Divergent regional patterns of cerebral hypoperfusion and gray matter atrophy in mild cognitive impairment patients.

PubMed

Wirth, Miranka; Pichet Binette, Alexa; Brunecker, Peter; Köbe, Theresa; Witte, A Veronica; Flöel, Agnes

2017-03-01

Reductions of cerebral blood flow and gray matter structure have been implicated in early pathogenesis of Alzheimer's disease, potentially providing complementary information. The present study evaluated regional patterns of cerebral hypoperfusion and atrophy in patients with mild cognitive impairment and healthy older adults. In each participant, cerebral perfusion and gray matter structure were extracted within selected brain regions vulnerable to Alzheimer's disease using magnetic resonance imaging. Measures were compared between diagnostic groups with/without adjustment for covariates. In mild cognitive impairment patients, cerebral blood flow was significantly reduced in comparison with healthy controls in temporo-parietal regions and the basal ganglia in the absence of local gray matter atrophy. By contrast, gray matter structure was significantly reduced in the hippocampus in the absence of local hypoperfusion. Both, cerebral perfusion and gray matter structure were significantly reduced in the entorhinal and isthmus cingulate cortex in mild cognitive impairment patients compared with healthy older adults. Our results demonstrated partly divergent patterns of temporo-parietal hypoperfusion and medial-temporal atrophy in mild cognitive impairment patients, potentially indicating biomarker sensitivity to dissociable pathological mechanisms. The findings support applicability of cerebral perfusion and gray matter structure as complementary magnetic resonance imaging-based biomarkers in early Alzheimer's disease detection, a hypothesis to be further evaluated in longitudinal studies.

The effectiveness of high-flow regional cerebral perfusion in Norwood stage I palliation.

PubMed

Miyaji, Kagami; Miyamoto, Takashi; Kohira, Satoshi; Yoshii, Takeshi; Itatani, Kei-Ichi; Sato, Hajime; Inoue, Nobuyuki

2011-11-01

Regional cerebral perfusion (RCP) has been shown to provide cerebral circulatory support during Norwood procedure. In our institution, high-flow RCP (HFRCP) from the right innominate artery has been induced to keep sufficient cerebral and somatic oxygen delivery via collateral vessels. We studied the effectiveness of HFRCP to regional cerebral and somatic tissue oxygenation in Norwood stage I palliation. Seventeen patients, who underwent the Norwood procedure, were separated into two groups: group C (n=6) using low-flow RCP and group H (n=11) using HFRCP (mean flow: 54 vs 92mlkg(-1)min(-1), P<0.0001). The mean duration of RCP was 64±10min (range, 49-86min) under the moderate hypothermia. Chlorpromazine (3.0mgkg(-1)) was given to group H patients before and during RCP to increase RCP flow. The mean radial arterial pressure was kept <50mmHg during RCP. To clarify the effectiveness of HFRCP for cerebral and somatic tissue oxygenation, cerebral regional oxygen saturation (rSO(2)) and systemic venous oxygenation (SvO(2)) during RCP were compared between the two groups. Changes in the lactate level before and after RCP, and changes in the blood urea nitrogen (BUN), creatinine, lactate dehydrogenase (LDH), and creatinine kinase (CK) levels before and after surgery, were also compared between the groups. Mean rSO(2) was 82.9±9.0% in group H and 65.9±10.7% in group C (P<0.05). Mean SvO(2) during RCP was 98.2±4.3% in group H and 85.4±9.7% in group C (P<0.01). During RCP, lactate concentration significantly increased in group C compared with that in group H (P<0.001). After surgery, the LDH and CK levels significantly increased in group C compared with that in group H (P<0.05). Our study revealed that HFRCP preserved sufficient cerebral and somatic tissue oxygenation during the Norwood procedure. The reduction of vascular resistance of collateral vessels increased both cerebral and somatic blood flow, resulting in improved tissue oxygen delivery. Copyright © 2011

Regional cerebral glucose metabolism in systemic lupus erythematosus patients with major depressive disorder.

PubMed

Saito, Tomoyuki; Tamura, Maasa; Chiba, Yuhei; Katsuse, Omi; Suda, Akira; Kamada, Ayuko; Ikura, Takahiro; Abe, Kie; Ogawa, Matsuyoshi; Minegishi, Kaoru; Yoshimi, Ryusuke; Kirino, Yohei; Ihata, Atsushi; Hirayasu, Yoshio

2017-08-15

Depression is frequently observed in patients with systemic lupus erythematosus (SLE). Neuropsychiatric SLE (NPSLE) patients often exhibit cerebral hypometabolism, but the association between cerebral metabolism and depression remains unclear. To elucidate the features of cerebral metabolism in SLE patients with depression, we performed brain 18F-fluoro-d-glucose positron emission tomography (FDG-PET) on SLE patients with and without major depressive disorder. We performed brain FDG-PET on 20 SLE subjects (5 male, 15 female). The subjects were divided into two groups: subjects with major depressive disorder (DSLE) and subjects without major depressive disorder (non-DSLE). Cerebral glucose metabolism was analyzed using the three-dimensional stereotactic surface projection (3D-SSP) program. Regional metabolism was evaluated by stereotactic extraction estimation (SEE), in which the whole brain was divided into segments. Every SLE subject exhibited cerebral hypometabolism, in contrast to the normal healthy subjects. Regional analysis revealed a significantly lower ER in the left medial frontal gyrus (p=0.0055) and the right medial frontal gyrus (p=0.0022) in the DSLE group than in the non-DSLE group. Hypometabolism in the medial frontal gyrus may be related to major depressive disorder in SLE. Larger studies are needed to clarify this relationship. Copyright © 2017 Elsevier B.V. All rights reserved.

Dynamic alteration of regional cerebral blood flow during carotid compression and proof of reversibility.

PubMed

Asahi, Kouichi; Hori, M; Hamasaki, N; Sato, S; Nakanishi, H; Kuwatsuru, R; Sasai, K; Aoki, S

2012-01-01

It is difficult to non-invasively visualize changes in regional cerebral blood flow caused by manual compression of the carotid artery. To visualize dynamic changes in regional cerebral blood flow during and after manual compression of the carotid artery. Two healthy volunteers were recruited. Anatomic features and flow directions in the circle of Willis were evaluated with time-of-flight magnetic resonance angiography (MRA) and two-dimensional phase-contrast (2DPC) MRA, respectively. Regional cerebral blood flow was visualized with territorial arterial spin-labeling magnetic resonance imaging (TASL-MRI). TASL-MRI and 2DPC-MRA were performed in three states: at rest, during manual compression of the right carotid artery, and after decompression. In one volunteer, time-space labeling inversion pulse (Time-SLIP) MRA was performed to confirm collateral flow. During manual carotid compression, in one volunteer, the right thalamus changed to be fed only by the vertebrobasilar system, and the right basal ganglia changed to be fed by the left internal carotid artery. In the other volunteer, the right basal ganglia changed to be fed by the vertebrobasilar system. 2DPC-MRA showed that the flow direction changed in the right A1 segment of the anterior cerebral artery and the right posterior communicating artery. Perfusion patterns and flow directions recovered after decompression. Time-SLIP MRA showed pial vessels and dural collateral circulation when the right carotid artery was manually compressed. Use of TASL-MRI and 2DPC-MRA was successful for non-invasive visualization of the dynamic changes in regional cerebral blood flow during and after manual carotid compression.

AltitudeOmics: effect of ascent and acclimatization to 5260 m on regional cerebral oxygen delivery.

PubMed

Subudhi, Andrew W; Fan, Jui-Lin; Evero, Oghenero; Bourdillon, Nicolas; Kayser, Bengt; Julian, Colleen G; Lovering, Andrew T; Roach, Robert C

2014-05-01

Cerebral hypoxaemia associated with rapid ascent to high altitude can be life threatening; yet, with proper acclimatization, cerebral function can be maintained well enough for humans to thrive. We investigated adjustments in global and regional cerebral oxygen delivery (DO2) as 21 healthy volunteers rapidly ascended and acclimatized to 5260 m. Ultrasound indices of cerebral blood flow in internal carotid and vertebral arteries were measured at sea level, upon arrival at 5260 m (ALT1; atmospheric pressure 409 mmHg) and after 16 days of acclimatization (ALT16). Cerebral DO2 was calculated as the product of arterial oxygen content and flow in each respective artery and summed to estimate global cerebral blood flow. Vascular resistances were calculated as the quotient of mean arterial pressure and respective flows. Global cerebral blood flow increased by ∼70% upon arrival at ALT1 (P < 0.001) and returned to sea-level values at ALT16 as a result of changes in cerebral vascular resistance. A reciprocal pattern in arterial oxygen content maintained global cerebral DO2 throughout acclimatization, although DO2 to the posterior cerebral circulation was increased by ∼25% at ALT1 (P = 0.032). We conclude that cerebral DO2 is well maintained upon acute exposure and acclimatization to hypoxia, particularly in the posterior and inferior regions of the brain associated with vital homeostatic functions. This tight regulation of cerebral DO2 was achieved through integrated adjustments in local vascular resistances to alter cerebral perfusion during both acute and chronic exposure to hypoxia. © 2013 The Authors. Experimental Physiology © 2013 The Physiological Society.

Chronic Stress Modulates Regional Cerebral Glucose Transporter Expression in an Age-Specific and Sexually-Dimorphic Manner

PubMed Central

Kelly, Sean D.; Harrell, Constance S.; Neigh, Gretchen N.

2014-01-01

Facilitative glucose transporters (GLUT) mediate glucose uptake across the blood-brain-barrier into neurons and glia. Deficits in specific cerebral GLUT isoforms are linked to developmental and neurological dysfunction, but less is known about the range of variation in cerebral GLUT expression in normal conditions and the effects of environmental influences on cerebral GLUT expression. Knowing that puberty is a time of increased cerebral plasticity, metabolic demand, and shifts in hormonal balance for males and females, we first assessed gene expression of five GLUT subtypes in four brain regions in male and female adolescent and adult Wistar rats. The data indicated that sex differences in GLUT expression were most profound in the hypothalamus, and the transition from adolescence to adulthood had the most profound effect on GLUT expression in the hippocampus. Next, given the substantial energetic demands during adolescence and prior demonstrations of the adverse effects of adolescent stress, we determined the extent to which chronic stress altered GLUT expression in males and females in both adolescence and adulthood. Chronic stress significantly altered cerebral GLUT expression in males and females throughout both developmental stages but in a sexually dimorphic and brain region-specific manner. Collectively, our data demonstrate that cerebral GLUTs are expressed differentially based on brain region, sex, age, and stress exposure. These results suggest that developmental and environmental factors influence GLUT expression in multiple brain regions. Given the importance of appropriate metabolic balance within the brain, further assessment of the functional implications of life stage and environmentally-induced changes in GLUTs are warranted. PMID:24382486

Low regional cerebral blood flow in burning mouth syndrome patients with depression.

PubMed

Liu, B-L; Yao, H; Zheng, X-J; Du, G-H; Shen, X-M; Zhou, Y-M; Tang, G-Y

2015-07-01

The main aims of this study were to (i) investigate the emotional disorder status of patients with burning mouth syndrome (BMS) and (ii) detect regional cerebral blood flow in BMS patients with the application of combined single-photon emission computed tomography and computed tomography (SPECT/CT). The degree of pain was measured using the visual analysis scale, and emotional disorder with the self-rating anxiety scale, self-rating depression scale, and Hamilton depression rating scale in 29 patients with BMS and 10 healthy controls. SPECT/CT was performed in 29 patients with BMS and 10 healthy controls, and statistical parametric mapping method was used for between-group analyses. The incidence rate of depression in patients with BMS was 31.0%. Compared to the control group, patients with BMS displayed significantly different depression and anxiety scales (P < 0.05). Significantly lower regional cerebral blood flow in the left parietal and left temporal lobes was recorded for BMS patients with depression (P < 0.05). Patients with BMS experience more depression and anxious emotion. Moreover, depression in patients with BMS may be associated with lower regional cerebral blood flow in the left temporal and left parietal lobes. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Quantifying China's regional economic complexity

NASA Astrophysics Data System (ADS)

Gao, Jian; Zhou, Tao

2018-02-01

China has experienced an outstanding economic expansion during the past decades, however, literature on non-monetary metrics that reveal the status of China's regional economic development are still lacking. In this paper, we fill this gap by quantifying the economic complexity of China's provinces through analyzing 25 years' firm data. First, we estimate the regional economic complexity index (ECI), and show that the overall time evolution of provinces' ECI is relatively stable and slow. Then, after linking ECI to the economic development and the income inequality, we find that the explanatory power of ECI is positive for the former but negative for the latter. Next, we compare different measures of economic diversity and explore their relationships with monetary macroeconomic indicators. Results show that the ECI index and the non-linear iteration based Fitness index are comparative, and they both have stronger explanatory power than other benchmark measures. Further multivariate regressions suggest the robustness of our results after controlling other socioeconomic factors. Our work moves forward a step towards better understanding China's regional economic development and non-monetary macroeconomic indicators.

Determinants of inclusive education of 8-12 year-old children with cerebral palsy in 9 European regions.

PubMed

Sentenac, Mariane; Ehlinger, Virginie; Michelsen, Susan Ishoy; Marcelli, Marco; Dickinson, Heather Olivia; Arnaud, Catherine

2013-01-01

The principle of inclusive education has been increasingly recognised over recent decades and most countries officially support schooling of children with disabilities in mainstream settings. The SPARCLE study offers the opportunity to report on the schooling practices for children with cerebral palsy according to the nature and severity of their impairments and the schooling policy in European regions. The aim of this paper is to describe the type of schooling of children with cerebral palsy in various European regions after controlling for relevant individual factors. Children aged 8-12 years with cerebral palsy from 9 European regions and their families were interviewed. Our findings support the hypothesis that between-region variations in the type of schooling are still significant after adjustment for individual factors; and that motor function and intellectual ability have different effects on inclusion in mainstream school, depending on the region. Copyright © 2012 Elsevier Ltd. All rights reserved.

Effects of blockade of cerebral lymphatic drainage on regional cerebral blood flow and brain edema after subarachnoid hemorrhage.

PubMed

Sun, Bao-Liang; Xia, Zuo-Li; Wang, Jing-Ru; Yuan, Hui; Li, Wen-Xia; Chen, Yu-She; Yang, Ming-Feng; Zhang, Su-Ming

2006-01-01

The study was designed to observe the influence of blockade of cerebral lymphatic drainage on the regional cerebral blood flow (rCBF) and brain edema after experimental subarachnoid hemorrhage (SAH). Wistar rats were divided into non-SAH, SAH, and SAH plus cervical lymphatic blockade (SAH + CLB) groups. Autologous arterial hemolysate was injected into rat's cisterna magna to induce SAH. The rCBF was recorded continuously by a laser Doppler flowmeter. Intracranial pressure (ICP) was also monitored. After 24 hours and 72 hours of SAH, the rats were sacrificed and the brain was harvested for water content detection. It was found that there was no obvious change of rCBF and brain water content during the experiment in non-SAH group. An immediate and persistent drop in rCBF was found in SAH group. The drop in rCBF was more obvious in SAH + CLB group. CLB also worsened the SAH-induced increase in ICP. The brain water content 24 hours and 72 hours after induction of SAH in SAH group increased significantly. CLB led to a further increase of brain water content. In conclusion, blockade of cerebral lymphatic drainage pathway deteriorates the secondary cerebral ischemia and brain edema after SAH.

Impact of Methamphetamine on Regional Metabolism and Cerebral Blood Flow after Traumatic Brain Injury

PubMed Central

O'Phelan, Kristine; Ernst, Thomas; Park, Dalnam; Stenger, Andrew; Denny, Katherine; Green, Deborah; Chang, Cherylee; Chang, Linda

2014-01-01

Substance abuse is a frequent comorbid condition among patients with Traumatic Brain Injury (TBI), but little is known about its potential additive or interactive effects on tissue injury or recovery from TBI. This study aims to evaluate changes in regional metabolism and cerebral perfusion in subjects who used methamphetamine(METH) prior to sustaining a TBI. We hypothesized that METH use would decrease pericontusional cerebral perfusion and markers of neuronal metabolism, in TBI patients compared to those without METH use. Methods This is a single center prospective observational study. Adults with moderate and severe TBI were included. MRI scanning was performed on a 3 Tesla scanner. MP-RAGE and FLAIR sequences as well as Metabolite spectra of NAA and lactate in pericontusional and contralateral voxels identified on the MP-RAGE scans. A spiral-based FAIR sequence was used for the acquisition of cerebral blood flow (CBF) maps. Regional CBF images were analyzed using Image J open source software. Pericontusional and contralateral CBF, NAA and lactate were assessed in the entire cohort and in the METH and non-METH groups. Results 17 subjects completed the MR studies. Analysis of entire cohort: Pericontusional NAA concentrations (5.81 ± 2.0 mM/kg) were 12% lower compared to the contralateral NAA (6.98 ± 1.2 mM/kg; p=0.03). Lactate concentrations and CBF were not significantly different between the two regions, however, regional cerebral blood flow was equally reduced in the two regions. Subgroup analysis: 41% of subjects tested positive for METH. The mean age, Glasgow Coma Scale and time to scan did not differ between groups. The two subject groups also had similar regional NAA and lactate. Pericontusional CBF was 60% lower in the METH users than the non-users, p=0.04; contralateral CBF did not differ between the groups. Conclusion This small study demonstrates that tissue metabolism is regionally heterogeneous after TBI and pericontusional perfusion was

Multichannel near infrared spectroscopy indicates regional variations in cerebral autoregulation in infants supported on extracorporeal membrane oxygenation

NASA Astrophysics Data System (ADS)

Papademetriou, Maria D.; Tachtsidis, Ilias; Elliot, Martin J.; Hoskote, Aparna; Elwell, Clare E.

2012-06-01

Assessing noninvasively cerebral autoregulation, the protective mechanism of the brain to maintain constant cerebral blood flow despite changes in blood pressure, is challenging. Infants on life support system (ECMO) for cardiorespiratory failure are at risk of cerebral autoregulation impairment and consequent neurological problems. We measured oxyhaemoglobin concentration (HbO2) by multichannel (12 channels) near-infrared spectroscopy (NIRS) in six infants during sequential changes in ECMO flow. Wavelet cross-correlation (WCC) between mean arterial pressure (MAP) and HbO2 was used to construct a time-frequency representation of the concordance between the two signals to assess the nonstationary aspect of cerebral autoregulation and investigate regional variations. Group data showed that WCC increases with decreasing ECMO flow indicating higher concordance between MAP and HbO2 and demonstrating loss of cerebral autoregulation at low ECMO flows. Statistically significant differences in WCC were observed between channels placed on the right and left scalp with channels on the right exhibiting higher values of WCC suggesting that the right hemisphere was more susceptible to disruption of cerebral autoregulation. Multichannel NIRS in conjunction with wavelet analysis methods can be used to assess regional variations in dynamic cerebral autoregulation with important clinical application in the management of critically ill children on life support systems.

USGS Regional Groundwater Availability Studies: Quantifying Aquifer Response

NASA Astrophysics Data System (ADS)

Reeves, H. W.

2017-12-01

The U.S. Geological Survey (USGS) identified six challenges in determining groundwater availability: 1) limited direct measurement, 2) varying response times for different systems, 3) varying spatial scales for different availability questions and aquifer systems, 4) varying tolerance to changes in water levels or outflows, 5) redistribution of stresses and potential return-flow of water pumped from the system, and 6) varying chemical quality of groundwater and the role of quality in determining suitability for different uses. USGS Regional groundwater availability studies are designed to address these challenges. USGS regional groundwater availability studies focus on quantifying the groundwater budget for principal aquifers and determining how this budget has changed in response to pumping or variations in climate. This focus requires relating limited measurements to a quantitative understanding of the temporal and spatial response of regional aquifers. For most principal aquifer studies, aquifer response is quantified using regional groundwater flow models, and USGS regional groundwater availability studies have provided test cases for the development and application of advanced modeling techniques and methods. Results from regional studies from the Lake Michigan Basin and Northern Atlantic Coastal Plain illustrate how different parts of these systems respond differently to pumping with some areas showing large drawdowns and others having much less drawdown but greater capture of discharge. The Central Valley and Mississippi Embayment studies show how extensive pumping and transfer of water have resulted in much more groundwater moving through the aquifer system under current conditions compared to pre-development. These and other results from regional studies will be explored to illustrate how regional groundwater availability and related studies address the six challenges to determining groundwater availability.

Dual role of cerebral blood flow in regional brain temperature control in the healthy newborn infant.

PubMed

Iwata, Sachiko; Tachtsidis, Ilias; Takashima, Sachio; Matsuishi, Toyojiro; Robertson, Nicola J; Iwata, Osuke

2014-10-01

Small shifts in brain temperature after hypoxia-ischaemia affect cell viability. The main determinants of brain temperature are cerebral metabolism, which contributes to local heat production, and brain perfusion, which removes heat. However, few studies have addressed the effect of cerebral metabolism and perfusion on regional brain temperature in human neonates because of the lack of non-invasive cot-side monitors. This study aimed (i) to determine non-invasive monitoring tools of cerebral metabolism and perfusion by combining near-infrared spectroscopy and echocardiography, and (ii) to investigate the dependence of brain temperature on cerebral metabolism and perfusion in unsedated newborn infants. Thirty-two healthy newborn infants were recruited. They were studied with cerebral near-infrared spectroscopy, echocardiography, and a zero-heat flux tissue thermometer. A surrogate of cerebral blood flow (CBF) was measured using superior vena cava flow adjusted for cerebral volume (rSVC flow). The tissue oxygenation index, fractional oxygen extraction (FOE), and the cerebral metabolic rate of oxygen relative to rSVC flow (CMRO₂ index) were also estimated. A greater rSVC flow was positively associated with higher brain temperatures, particularly for superficial structures. The CMRO₂ index and rSVC flow were positively coupled. However, brain temperature was independent of FOE and the CMRO₂ index. A cooler ambient temperature was associated with a greater temperature gradient between the scalp surface and the body core. Cerebral oxygen metabolism and perfusion were monitored in newborn infants without using tracers. In these healthy newborn infants, cerebral perfusion and ambient temperature were significant independent variables of brain temperature. CBF has primarily been associated with heat removal from the brain. However, our results suggest that CBF is likely to deliver heat specifically to the superficial brain. Further studies are required to assess the

Cerebral oxygenation in patients undergoing shoulder surgery in beach chair position: comparing general to regional anesthesia and the impact on neurobehavioral outcome.

PubMed

Aguirre, J; Borgeat, A; Trachsel, T; Cobo Del Prado, I; De Andrés, J; Bühler, P

2014-02-01

Ischemic brain damage has been reported in healthy patients after beach chair position for surgery due to cerebral hypoperfusion. Near-infrared spectroscopy has been described as a non-invasive, continuous method to monitor cerebral oxygen saturation. However, its impact on neurobehavioral outcome comparing different anesthesia regimens has been poorly described. In this prospective, assessor-blinded study, 90 patients undergoing shoulder surgery in beach chair position following general (G-group, n=45) or regional anesthesia (R-group; n=45) were enrolled to assess the prevalence of cerebral desaturation events comparing anesthesia regimens and their impact on neurobehavioral and neurological outcome. Anesthesiologists were blinded to regional cerebral oxygen saturation values. Baseline data assessed the day before surgery included neurological and neurobehavioral tests, which were repeated the day after surgery. The baseline data for regional cerebral oxygen saturation/bispectral index and invasive blood pressure both at heart and auditory meatus levels were taken prior to anesthesia, 5 min after induction of anesthesia, 5 min after beach chair positioning, after skin incision and thereafter all 20 min until discharge. Patients in the R-group showed significantly less cerebral desaturation events (p<0.001), drops in regional cerebral oxygen saturation values (p<0.001), significantly better neurobehavioral test results the day after surgery (p<0.001) and showed a greater hemodynamic stability in the beach chair position compared to patients in the G-group. The incidence of regional cerebral oxygen desaturations seems to influence the neurobehavioral outcome. Regional anesthesia offers more stable cardiovascular conditions for shoulder surgery in beach chair position influencing neurobehavioral test results at 24h. Copyright © 2013 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Published by Elsevier España. All rights reserved.

In Vivo Theranostics at the Peri-Infarct Region in Cerebral Ischemia

PubMed Central

Agulla, Jesús; Brea, David; Campos, Francisco; Sobrino, Tomás; Argibay, Bárbara; Al-Soufi, Wajih; Blanco, Miguel; Castillo, José; Ramos-Cabrer, Pedro

2014-01-01

The use of theranostics in neurosciences has been rare to date because of the limitations imposed on the free delivery of substances to the brain by the blood-brain barrier. Here we report the development of a theranostic system for the treatment of stroke, a leading cause of death and disability in developed countries. We first performed a series of proteomic, immunoblotting and immunohistological studies to characterize the expression of molecular biomarkers for the so-called peri-infarct tissue, a key region of the brain for stroke treatment. We confirmed that the HSP72 protein is a suitable biomarker for the peri-infarct region, as it is selectively expressed by at-risk tissue for up to 7 days following cerebral ischemia. We also describe the development of anti-HSP72 vectorized stealth immunoliposomes containing imaging probes to make them traceable by conventional imaging techniques (fluorescence and MRI) that were used to encapsulate a therapeutic agent (citicoline) for the treatment of cerebral ischemia. We tested the molecular recognition capabilities of these nano-platforms in vitro together with their diagnostic and therapeutic properties in vivo, in an animal model of cerebral ischemia. Using MRI, we found that 80% of vectorized liposomes were located on the periphery of the ischemic lesion, and animals treated with citicoline encapsulated on these liposomes presented lesion volumes up to 30% smaller than animals treated with free (non-encapsulated) drugs. Our results show the potential of nanotechnology for the development of effective tools for the treatment of neurological diseases. PMID:24396517

Relations of Blood Pressure and Head Injury to Regional Cerebral Blood Flow

PubMed Central

Allen, Allyssa J.; Katzel, Leslie I.; Wendell, Carrington R.; Siegel, Eliot L.; Lefkowitz, David; Waldstein, Shari R.

2016-01-01

Hypertension confers increased risk for cognitive decline, dementia, and cerebrovascular disease. These associations have been attributed, in part, to cerebral hypoperfusion. Here we posit that relations of higher blood pressure to lower levels of cerebral perfusion may be potentiated by a prior head injury. Participants were 87 community-dwelling older adults -69% men, 90% white, mean age= 66.9 years, 27.6% with a history of mild traumatic brain injury (mTBI) defined as a loss of consciousness regions. Cerebellum served as the denominator. Sex-stratified multiple regression analyses, adjusted for age, education, race, alcohol consumption, smoking status, and depressive symptomatology, revealed significant interactions of blood pressure and head injury to cerebral blood flow in men only. Specifically, among men with a history of head injury, higher systolic blood pressure was associated with lower levels of perfusion in the left orbital (β=-3.21, p=.024) and left dorsolateral (β=-2.61, p=.042) prefrontal cortex, and left temporal cortex (β=-3.36, p=.014); higher diastolic blood pressure was marginally associated with lower levels of perfusion in the left dorsolateral prefrontal cortex (β=-2.79, p=.051). Results indicate that men with a history of head injury may be particularly vulnerable to the impact of higher blood pressure on cerebral perfusion in left anterior cortical regions, thus potentially enhancing risk for adverse brain and neurocognitive outcomes. PMID:27206865

Real-time imaging of cerebral infarction in rabbits using electrical impedance tomography.

PubMed

Yang, Bin; Shi, Xuetao; Dai, Meng; Xu, Canhua; You, Fushen; Fu, Feng; Liu, Ruigang; Dong, Xiuzhen

2014-02-01

To investigate the possible use of electrical impedance tomography (EIT) in monitoring focal cerebral infarction in a rabbit model. A model of focal cerebral infarction was established in eight New Zealand rabbits using a photochemical method without craniectomy. Focal cerebral infarction was confirmed by histopathological examination. Intracranial impedance variation was measured using 16 electrodes placed in a circle on the scalp. EIT images were obtained using a damped least-squares reconstruction algorithm. The average resistivity value (ARV) of the infarct region on EIT images was calculated to quantify relative resistivity changes. A symmetry index was calculated to evaluate the relative difference in resistivity between the two sides of the cerebrum. EIT images and ARV curves showed that impedance changes caused by cerebral infarction increased linearly with irradiation time. A difference in ARV was found between measurements taken before and after infarct induction. Focal cerebral infarction can be monitored by EIT in the proposed animal model. The results are sufficiently encouraging that the authors plan to extend this study to humans, after further technical improvements.

Neuropsychological and structural brain lesions in multiple sclerosis: a regional analysis.

PubMed

Swirsky-Sacchetti, T; Mitchell, D R; Seward, J; Gonzales, C; Lublin, F; Knobler, R; Field, H L

1992-07-01

Quantified lesion scores derived from MRI correlate significantly with neuropsychological testing in patients with multiple sclerosis (MS). Variables used to reflect disease severity include total lesion area (TLA), ventricular-brain ratio, and size of the corpus callosum. We used these general measures of cerebral lesion involvement as well as specific ratings of lesion involvement by frontal, temporal, and parieto-occipital regions to quantify the topographic distribution of lesions and consequent effects upon cognitive function. Lesions were heavily distributed in the parieto-occipital regions bilaterally. Neuropsychological tests were highly related to all generalized measures of cerebral involvement, with TLA being the best predictor of neuropsychological deficit. Mean TLA for the cognitively impaired group was 28.30 cm2 versus 7.41 cm2 for the cognitively intact group (p less than 0.0001). Multiple regression analyses revealed that left frontal lobe involvement best predicted impaired abstract problem solving, memory, and word fluency. Left parieto-occipital lesion involvement best predicted deficits in verbal learning and complex visual-integrative skills. Analysis of regional cerebral lesion load may assist in understanding the particular pattern and course of cognitive deficits in MS.

Cerebral Cortex Regions Selectively Vulnerable to Radiation Dose-Dependent Atrophy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Seibert, Tyler M.; Karunamuni, Roshan; Kaifi, Samar

Purpose and Objectives: Neurologic deficits after brain radiation therapy (RT) typically involve decline in higher-order cognitive functions such as attention and memory rather than sensory defects or paralysis. We sought to determine whether areas of the cortex critical to cognition are selectively vulnerable to radiation dose-dependent atrophy. Methods and Materials: We measured change in cortical thickness in 54 primary brain tumor patients who underwent fractionated, partial brain RT. The study patients underwent high-resolution, volumetric magnetic resonance imaging (T1-weighted; T2 fluid-attenuated inversion recovery, FLAIR) before RT and 1 year afterward. Semiautomated software was used to segment anatomic regions of the cerebral cortex formore » each patient. Cortical thickness was measured for each region before RT and 1 year afterward. Two higher-order cortical regions of interest (ROIs) were tested for association between radiation dose and cortical thinning: entorhinal (memory) and inferior parietal (attention/memory). For comparison, 2 primary cortex ROIs were also tested: pericalcarine (vision) and paracentral lobule (somatosensory/motor). Linear mixed-effects analyses were used to test all other cortical regions for significant radiation dose-dependent thickness change. Statistical significance was set at α = 0.05 using 2-tailed tests. Results: Cortical atrophy was significantly associated with radiation dose in the entorhinal (P=.01) and inferior parietal ROIs (P=.02). By contrast, no significant radiation dose-dependent effect was found in the primary cortex ROIs (pericalcarine and paracentral lobule). In the whole-cortex analysis, 9 regions showed significant radiation dose-dependent atrophy, including areas responsible for memory, attention, and executive function (P≤.002). Conclusions: Areas of cerebral cortex important for higher-order cognition may be most vulnerable to radiation-related atrophy. This is consistent with clinical

Apparent diffusion coefficient evaluation for secondary changes in the cerebellum of rats after middle cerebral artery occlusion

PubMed Central

Yang, Yunjun; Gao, Lingyun; Fu, Jun; Zhang, Jun; Li, Yuxin; Yin, Bo; Chen, Weijian; Geng, Daoying

2013-01-01

Supratentorial cerebral infarction can cause functional inhibition of remote regions such as the cerebellum, which may be relevant to diaschisis. This phenomenon is often analyzed using positron emission tomography and single photon emission CT. However, these methods are expensive and radioactive. Thus, the present study quantified the changes of infarction core and remote regions after unilateral middle cerebral artery occlusion using apparent diffusion coefficient values. Diffusion-weighted imaging showed that the area of infarction core gradually increased to involve the cerebral cortex with increasing infarction time. Diffusion weighted imaging signals were initially increased and then stabilized by 24 hours. With increasing infarction time, the apparent diffusion coefficient value in the infarction core and remote bilateral cerebellum both gradually decreased, and then slightly increased 3–24 hours after infarction. Apparent diffusion coefficient values at remote regions (cerebellum) varied along with the change of supratentorial infarction core, suggesting that the phenomenon of diaschisis existed at the remote regions. Thus, apparent diffusion coefficient values and diffusion weighted imaging can be used to detect early diaschisis. PMID:25206615

Development of a NIRS method to quantify cerebral perfusion and oxidative metabolism in preterm infants with post-hemorrhagic ventricle dilation (Conference Presentation)

NASA Astrophysics Data System (ADS)

McLachlan, Peter; Kishimoto, Jessica; de Ribeaupierre, Sandrine; Lee, David S. C.; Diop, Mamadou; St Lawrence, Keith

2017-02-01

A complication of intraventricular hemorrhage among preterm neonates is post-hemorrhagic ventricle dilation (PHVD), which is associated with a greater risk of life-long neurological disability. Clinical evidence, including suppressed EEG patterns, suggests that cerebral perfusion and oxygenation is impaired in these patients, likely due to elevated intracranial pressure (ICP). Cerebral blood flow (CBF) and the cerebral metabolic rate of oxygen (CMRO2) can be quantified by dynamic contrast-enhanced NIRS; however, PHVD poses a unique challenge to NIRS since the cerebral mantle can be compressed to 1 cm or less. The objectives of this work were to develop a finite-slab model for the analysis of NIRS spectra, incorporating depth measurements from ultrasound images, and to assess the magnitude of error when using the standard semi-infinite model. CBF, tissue saturation (StO2) and CMRO2 were measured in 9 patients receiving ventricle taps to reduce ICP. Monte Carlo simulations indicated that errors in StO2 could be greater than 20% if the cerebral mantle was reduced to 1 cm. Using the finite-slab model, basal CBF and CMRO2 in the PHVD patients were not significantly different from a control group of preterm infants (14.6 ± 4.2 ml/100 g/min and 1.0 ± 0.4 ml O2/100 g/min), but StO2 was significantly lower (PDA 70.5 ± 9%, PHVD 58.9 ± 12%). Additionally, ventricle tapping improved CBF by 15.6 ± 22%. This work indicates that applying NIRS to PHVD patients is prone to error; however, this issue can be overcome with the appropriate model and using readily available ultrasound images.

Quantifying the physical, social and attitudinal environment of children with cerebral palsy.

PubMed

Dickinson, Heather O; Colver, Allan

2011-01-01

To develop an instrument to represent the availability of needed environmental features (EFs) in the physical, social and attitudinal environment of home, school and community for children with cerebral palsy. Following a literature review and qualitative studies, the European Child Environment Questionnaire (ECEQ) was developed to capture whether EFs needed by children with cerebral palsy were available to them: 24, 24 and 12 items related to the physical, social and attitudinal environments, respectively. The ECEQ was administered to parents of 818 children with cerebral palsy aged 8-12 years, in seven European countries. A domain structure was developed using factor analysis. Parents responded to 98% of items. Seven items were omitted from statistical models as the EFs they referred to were available to most children who needed them; two items were omitted as they did not fit well into plausible domains. The final domains, based on 51 items, were: Transport, Physical - home, Physical - community, Physical - school, Social support - home, Social support - community, Attitudes - family and friends, Attitudes - teachers and therapists, Attitudes - classmates. ECEQ was acceptable to parents and can be used to assess both the access children with cerebral palsy have to the EFs that they need and how available individual EFs are.

Regional cerebral blood flow changes associated with focal electrically administered seizure therapy (FEAST).

PubMed

Chahine, George; Short, Baron; Spicer, Ken; Schmidt, Matthew; Burns, Carol; Atoui, Mia; George, Mark S; Sackeim, Harold A; Nahas, Ziad

2014-01-01

Use of electroconvulsive therapy (ECT) is limited by cognitive disturbance. Focal electrically-administered seizure therapy (FEAST) is designed to initiate focal seizures in the prefrontal cortex. To date, no studies have documented the effects of FEAST on regional cerebral blood flow (rCBF). A 72 year old depressed man underwent three single photon emission computed tomography (SPECT) scans to capture the onset and resolution of seizures triggered with right unilateral FEAST. We used Bioimage Suite for within-subject statistical analyses of perfusion differences ictally and post-ictally compared with the baseline scan. Early ictal increases in regional cerebral blood flow (rCBF) were limited to the right prefrontal cortex. Post-ictally, perfusion was reduced in bilateral frontal and occipital cortices and increased in left motor and precuneus cortex. FEAST appears to triggers focal onsets of seizure activity in the right prefrontal cortex with subsequent generalization. Future studies are needed on a larger sample. Copyright © 2014 Elsevier Inc. All rights reserved.

A Mobile Device for Measuring Regional Cerebral Circulation

PubMed Central

Howard, George; Griffith, David W.; Stump, David A.; Hinschelwood, Laura

1980-01-01

Immobility and costs of currently available regional cerebral blood flow (rCBF) equipment usually require having a single fixed blood flow lab, which cannot be used to study non-ambulatory patients who are often the most interesting to study. After careful study of the information flow between the steps involved in the collection, analysis and display of data, a new rCBF machine has been developed with a mobile satellite and a host processor. The satellite is equipped with a Z-80 microprocessor which controls the data collection, screen formating, data display and communications with the host. The host provides the processing power necessary for moderately complex curve fitting and data storage.

Quantifying climate feedbacks in polar regions.

PubMed

Goosse, Hugues; Kay, Jennifer E; Armour, Kyle C; Bodas-Salcedo, Alejandro; Chepfer, Helene; Docquier, David; Jonko, Alexandra; Kushner, Paul J; Lecomte, Olivier; Massonnet, François; Park, Hyo-Seok; Pithan, Felix; Svensson, Gunilla; Vancoppenolle, Martin

2018-05-15

The concept of feedback is key in assessing whether a perturbation to a system is amplified or damped by mechanisms internal to the system. In polar regions, climate dynamics are controlled by both radiative and non-radiative interactions between the atmosphere, ocean, sea ice, ice sheets and land surfaces. Precisely quantifying polar feedbacks is required for a process-oriented evaluation of climate models, a clear understanding of the processes responsible for polar climate changes, and a reduction in uncertainty associated with model projections. This quantification can be performed using a simple and consistent approach that is valid for a wide range of feedbacks, offering the opportunity for more systematic feedback analyses and a better understanding of polar climate changes.

Cerebral Perfusion Is Perturbed by Preterm Birth and Brain Injury.

PubMed

Mahdi, E S; Bouyssi-Kobar, M; Jacobs, M B; Murnick, J; Chang, T; Limperopoulos, C

2018-05-10

Early disturbances in systemic and cerebral hemodynamics are thought to mediate prematurity-related brain injury. However, the extent to which CBF is perturbed by preterm birth is unknown. Our aim was to compare global and regional CBF in preterm infants with and without brain injury on conventional MR imaging using arterial spin-labeling during the third trimester of ex utero life and to examine the relationship between clinical risk factors and CBF. We prospectively enrolled preterm infants younger than 32 weeks' gestational age and <1500 g and performed arterial spin-labeling MR imaging studies. Global and regional CBF in the cerebral cortex, thalami, pons, and cerebellum was quantified. Preterm infants were stratified into those with and without structural brain injury. We further categorized preterm infants by brain injury severity: moderate-severe and mild. We studied 78 preterm infants: 31 without brain injury and 47 with brain injury (29 with mild and 18 with moderate-severe injury). Global CBF showed a borderline significant increase with increasing gestational age at birth ( P = .05) and trended lower in preterm infants with brain injury ( P = .07). Similarly, regional CBF was significantly lower in the right thalamus and midpons ( P < .05) and trended lower in the midtemporal, left thalamus, and anterior vermis regions ( P < .1) in preterm infants with brain injury. Regional CBF in preterm infants with moderate-severe brain injury trended lower in the midpons, right cerebellar hemisphere, and dentate nuclei compared with mild brain injury ( P < .1). In addition, a significant, lower regional CBF was associated with ventilation, sepsis, and cesarean delivery ( P < .05). We report early disturbances in global and regional CBF in preterm infants following brain injury. Regional cerebral perfusion alterations were evident in the thalamus and pons, suggesting regional vulnerability of the developing cerebro-cerebellar circuitry. © 2018 by American Journal of

Orthostatic hypotension, cerebral hypoperfusion, and visuospatial deficits in Lewy body disorders.

PubMed

Robertson, Andrew D; Messner, Michelle A; Shirzadi, Zahra; Kleiner-Fisman, Galit; Lee, Joyce; Hopyan, Julia; Lang, Anthony E; Black, Sandra E; MacIntosh, Bradley J; Masellis, Mario

2016-01-01

Orthostatic hypotension and cognitive impairment are two non-motor attributes of Lewy body spectrum disorders that impact independence. This proof-of-concept study examined cerebral blood flow (perfusion) as a mediator of orthostatic hypotension and cognition. In fifteen patients with Lewy body disorders, we estimated regional perfusion using pseudo-continuous arterial spin labeling MRI, and quantified orthostatic hypotension from the change in systolic blood pressure between supine and standing positions. Executive, visuospatial, attention, memory, and language domains were characterized by neuropsychological tests. A matching sample of non-demented adults with cerebral small vessel disease was obtained to contrast perfusion patterns associated with comorbid vascular pathology. Compared to the vascular group, patients with Lewy body disorders exhibited lower perfusion to temporal and occipital lobes than to frontal and parietal lobes (q < 0.05). A greater orthostatic drop in systolic pressure was associated with lower occipito-parietal perfusion in these patients (uncorrected p < 0.005; cluster size ≥ 20 voxels). Although orthostatic hypotension and supine hypertension were strongly correlated (r = -0.79, p < 0.001), the patterns of association for each with perfusion were distinct. Specifically, supine hypertension was associated with high perfusion to anterior and middle cerebral arterial territories, as well as with low perfusion to posterior regions. Perfusion within orthostatic hypotension-defined regions was directly related to performance on visuospatial and attention tasks, independent of dementia severity (p < 0.05). These findings provide new insight that regional cerebral hypoperfusion is related to orthostatic hypotension, and may be involved in domain-specific cognitive deficits in Lewy body disorders. Copyright © 2015 Elsevier Ltd. All rights reserved.

Differential diagnosis of regional cerebral hyperfixation of TC-99m HMPAO on SPECT imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shirazi, P.; Konopka, L.; Crayton, J.W.

1994-05-01

Accurate diagnostic evaluation of patients with neurologic and neuropsychiatric disease is important because early treatment may halt disease progression and prevent impairment or disability. Cerebral hyperfixation of HMPAO has been ascribed to luxury perfusion following ischemic infarction. The present study sought to identify other conditions that also display radiotracer hyperfixation in order to develop a differential diagnosis of this finding on SPECT imaging. Two hundred fifty (n=250) successive cerebral SPECT images were reviewed for evidence of HMPAO hyperfixation. Hyperfixation was defined as enhanced focal perfusion surrounded by a zone of diminished or normal cerebral perfusion. All patients were scanned aftermore » intravenous injection of 25 mCi Tc-99m HMPAO. Volume-rendered and oblique images were obtained with a Trionix triple-head SPECT system using ultra high resolution fan beam collimators. Thirteen (13/250; 5%) of the patients exhibited regions of HMPAO hyperfixation. CT or MRI abnormalities were detected in 6/13 cases. Clinical diagnoses in these patients included intractable psychosis, post-traumatic stress disorder, alcohol and narcotic dependence, major depression, acute closed-head trauma, hypothyroidism, as well as subacute ischemic infarction. A wide variety of conditions may be associated with cerebral hyperfixation of HMPAO. These conditions include neurologic and psychiatric diagnoses, and extend the consideration of hyperfixation beyond ischemic infarction. Consequently, a differential diagnosis of HMPAO hyperfixation may be broader than originally considered, and this may suggest a fundamental role for local cerebral hyperperfusion. Elucidation of the fundamental mechanism(s) for cerebral hyperperfusion requires further investigation.« less

Common and Dissociable Regional Cerebral Blood Flow Differences Associate with Dimensions of Psychopathology Across Categorical Diagnoses

PubMed Central

Kaczkurkin, Antonia N.; Moore, Tyler M.; Calkins, Monica E.; Ciric, Rastko; Detre, John A.; Elliott, Mark A.; Foa, Edna B.; de La Garza, Angel Garcia; Roalf, David R.; Rosen, Adon; Ruparel, Kosha; Shinohara, Russell T.; Xia, Cedric H.; Wolf, Daniel H.; Gur, Raquel E.; Gur, Ruben C.; Satterthwaite, Theodore D.

2017-01-01

The high comorbidity among neuropsychiatric disorders suggests a possible common neurobiological phenotype. Resting-state regional cerebral blood flow (CBF) can be measured noninvasively with MRI and abnormalities in regional CBF are present in many neuropsychiatric disorders. Regional CBF may also provide a useful biological marker across different types of psychopathology. To investigate CBF changes common across psychiatric disorders, we capitalized upon a sample of 1,042 youths (ages 11 to 23 years) who completed cross-sectional imaging as part of the Philadelphia Neurodevelopmental Cohort. CBF during a resting state was quantified on a voxelwise basis using arterial spin labeled perfusion MRI at 3T. A dimensional measure of psychopathology was constructed using a bifactor model of item-level data from a psychiatric screening interview, which delineated four factors (fear, anxious-misery, psychosis, and behavioral symptoms) plus a general factor: overall psychopathology. Overall psychopathology was associated with elevated perfusion in several regions including the right dorsal anterior cingulate cortex (ACC) and left rostral ACC. Furthermore, several clusters were associated with specific dimensions of psychopathology. Psychosis symptoms were related to reduced perfusion in the left frontal operculum and insula, whereas fear symptoms were associated with less perfusion in the right occipital/fusiform gyrus and left subgenual ACC. Follow-up functional connectivity analyses using resting-state fMRI collected in the same participants revealed that overall psychopathology was associated with decreased connectivity between the dorsal ACC and bilateral caudate. Together, the results of this study demonstrate common and dissociable CBF abnormalities across neuropsychiatric disorders in youth. PMID:28924181

Regional gray matter growth, sexual dimorphism, and cerebral asymmetry in the neonatal brain.

PubMed

Gilmore, John H; Lin, Weili; Prastawa, Marcel W; Looney, Christopher B; Vetsa, Y Sampath K; Knickmeyer, Rebecca C; Evans, Dianne D; Smith, J Keith; Hamer, Robert M; Lieberman, Jeffrey A; Gerig, Guido

2007-02-07

Although there has been recent interest in the study of childhood and adolescent brain development, very little is known about normal brain development in the first few months of life. In older children, there are regional differences in cortical gray matter development, whereas cortical gray and white matter growth after birth has not been studied to a great extent. The adult human brain is also characterized by cerebral asymmetries and sexual dimorphisms, although very little is known about how these asymmetries and dimorphisms develop. We used magnetic resonance imaging and an automatic segmentation methodology to study brain structure in 74 neonates in the first few weeks after birth. We found robust cortical gray matter growth compared with white matter growth, with occipital regions growing much faster than prefrontal regions. Sexual dimorphism is present at birth, with males having larger total brain cortical gray and white matter volumes than females. In contrast to adults and older children, the left hemisphere is larger than the right hemisphere, and the normal pattern of fronto-occipital asymmetry described in older children and adults is not present. Regional differences in cortical gray matter growth are likely related to differential maturation of sensory and motor systems compared with prefrontal executive function after birth. These findings also indicate that whereas some adult patterns of sexual dimorphism and cerebral asymmetries are present at birth, others develop after birth.

Quantifying climate feedbacks in polar regions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goosse, Hugues; Kay, Jennifer E.; Armour, Kyle C.

The concept of feedback is key in assessing whether a perturbation to a system is amplified or damped by mechanisms internal to the system. In polar regions, climate dynamics are controlled by both radiative and non-radiative interactions between the atmosphere, ocean, sea ice, ice sheets and land surfaces. Precisely quantifying polar feedbacks is required for a process-oriented evaluation of climate models, a clear understanding of the processes responsible for polar climate changes, and a reduction in uncertainty associated with model projections. This quantification can be performed using a simple and consistent approach that is valid for a wide range ofmore » feedbacks, thus offering the opportunity for more systematic feedback analyses and a better understanding of polar climate changes.« less

Quantifying climate feedbacks in polar regions

DOE PAGES

Goosse, Hugues; Kay, Jennifer E.; Armour, Kyle C.; ...

2018-05-15

The concept of feedback is key in assessing whether a perturbation to a system is amplified or damped by mechanisms internal to the system. In polar regions, climate dynamics are controlled by both radiative and non-radiative interactions between the atmosphere, ocean, sea ice, ice sheets and land surfaces. Precisely quantifying polar feedbacks is required for a process-oriented evaluation of climate models, a clear understanding of the processes responsible for polar climate changes, and a reduction in uncertainty associated with model projections. This quantification can be performed using a simple and consistent approach that is valid for a wide range ofmore » feedbacks, thus offering the opportunity for more systematic feedback analyses and a better understanding of polar climate changes.« less

Brain region-selective mechanisms contribute to the progression of cerebral alterations in acute liver failure in rats.

PubMed

Cauli, Omar; López-Larrubia, Pilar; Rodrigo, Regina; Agusti, Ana; Boix, Jordi; Nieto-Charques, Laura; Cerdán, Sebastián; Felipo, Vicente

2011-02-01

Patients with acute liver failure (ALF) often die of intracranial pressure (IP) and cerebral herniation. Main contributors to increased IP are ammonia, glutamine, edema, and blood flow. The sequence of events and underlying mechanisms, as well as the temporal pattern, regional distribution, and contribution of each parameter to the progression of neurologic deterioration and IP, are unclear. We studied rats with ALF to follow the progression of changes in ammonia, glutamine, grade and type (vasogenic or cytotoxic) of edema, blood-brain barrier permeability, cerebral blood flow, and IP. We assessed whether the changes in these parameters were similar between frontal cortex and cerebellum and evaluated the presence, type, and progression of edema in 12 brain areas. ALF was induced by injection of galactosamine. The grade and type of edema was assessed by measuring the apparent diffusion coefficient by magnetic resonance imaging. Cerebral blood flow was measured by magnetic resonance and blood-brain barrier permeability by Evans blue-albumin extravasation. Increased IP arises from an early increase of blood-brain barrier permeability in certain areas (including cerebellum but not frontal cortex) followed by vasogenic edema. Ammonia and glutamine then increase progressively, leading to cytotoxic edema in many areas. Alterations in lactate and cerebral blood flow are later events that further increase IP. Different mechanisms in specific regions of the brain contribute, with different temporal patterns, to the progression of cerebral alterations and IP in ALF. Copyright © 2011 AGA Institute. Published by Elsevier Inc. All rights reserved.

Meta-analyses of structural regional cerebral effects in type 1 and type 2 diabetes.

PubMed

Moulton, Calum D; Costafreda, Sergi G; Horton, Paul; Ismail, Khalida; Fu, Cynthia H Y

2015-12-01

Diabetes is associated with macrovascular and microvascular complications and is a major risk factor for neurological and psychiatric disorders, such as dementia and depression. Type 1 diabetes (T1DM) and type 2 diabetes (T2DM) have distinct etiologies and pathophysiological effects while sharing a common endpoint of persistent hyperglycemia. Neuroimaging studies in T1DM have revealed reductions in numerous regions, including the parahippocampal and occipital regions, while in T2DM there have been numerous reports of hippocampal atrophy. This meta-analysis aimed to identify consistent regional abnormalities in cerebral structures in T1DM and T2DM respectively, and also to examine the impact of potential confounds, including age, depression and vascular risk factors. Neuroimaging studies of both voxel-based morphometry (VBM) data and volumetric data were included. Ten T1DM studies (n = 613 patients) and 23 T2DM studies (n = 1364 patients) fulfilled inclusion criteria. The T1DM meta-analysis revealed reduced bilateral thalamus grey matter density in adults. The T2DM meta-analysis revealed reduced global brain volume and regional atrophy in the hippocampi, basal ganglia, and orbitofrontal and occipital lobes. Moreover, hippocampal atrophy in T2DM was not modified by hypertension, although there were more marked reductions in younger patients relative to healthy controls. In conclusion, T1DM and T2DM demonstrated distinct cerebral effects with generalised and specific target areas of grey matter reduction. Thalamic atrophy in T1DM may be a substrate of associated cognitive deficits. In T2DM, global cerebral atrophy may reflect atherosclerotic factors, while hippocampal atrophy was an independent effect providing a potential common neuropathological etiology for the comorbidity of T2DM with dementia and depression.

Using High Resolution Regional Climate Models to Quantify the Snow Albedo Feedback in a Region of Complex Terrain

NASA Astrophysics Data System (ADS)

Letcher, T.; Minder, J. R.

2015-12-01

High resolution regional climate models are used to characterize and quantify the snow albedo feedback (SAF) over the complex terrain of the Colorado Headwaters region. Three pairs of 7-year control and pseudo global warming simulations (with horizontal grid spacings of 4, 12, and 36 km) are used to study how the SAF modifies the regional climate response to a large-scale thermodynamic perturbation. The SAF substantially enhances warming within the Headwaters domain, locally as much as 5 °C in regions of snow loss. The SAF also increases the inter-annual variability of the springtime warming within Headwaters domain under the perturbed climate. Linear feedback analysis is used quantify the strength of the SAF. The SAF attains a maximum value of 4 W m-2 K-1 during April when snow loss coincides with strong incoming solar radiation. On sub-seasonal timescales, simulations at 4 km and 12 km horizontal grid-spacing show good agreement in the strength and timing of the SAF, whereas a 36km simulation shows greater discrepancies that are tired to differences in snow accumulation and ablation caused by smoother terrain. An analysis of the regional energy budget shows that transport by atmospheric motion acts as a negative feedback to regional warming, damping the effects of the SAF. On the mesoscale, this transport causes non-local warming in locations with no snow. The methods presented here can be used generally to quantify the role of the SAF in other regional climate modeling experiments.

Regional cerebral blood flow in Parkinson disease with nonpsychotic visual hallucinations.

PubMed

Oishi, N; Udaka, F; Kameyama, M; Sawamoto, N; Hashikawa, K; Fukuyama, H

2005-12-13

Patients with Parkinson disease (PD) often experience visual hallucinations (VH) with retained insight (nonpsychotic) but the precise mechanism remains unclear. To clarify which neural substrates participate in nonpsychotic VH in PD, the authors evaluated regional cerebral blood flow (rCBF) changes in patients with PD and VH. The authors compared 24 patients with PD who had nonpsychotic VH (hallucinators) and 41 patients with PD who had never experienced VH (non-hallucinators) using SPECT images with N-isopropyl-p-[(123)I]iodoamphetamine. There were no significant differences in age, sex, duration of disease, doses of PD medications, Hoehn and Yahr scale, or Mini-Mental State Examination (MMSE) scores between the two groups. The rCBF data were analyzed using statistical parametric mapping (SPM). The rCBF in the right fusiform gyrus was lower in the hallucinators than in the non-hallucinators (corrected p < 0.05 at cluster levels). The hallucinators revealed higher rCBF in the right superior and middle temporal gyri than the non-hallucinators (uncorrected p < 0.001). These significant differences were demonstrated after MMSE scores and duration of disease, which are the relevant factors associated with VH, were covariated out. Nonpsychotic visual hallucinations in Parkinson disease (PD) may be associated with hypoperfusion in the right fusiform gyrus and hyperperfusion in the right superior and middle temporal gyri. These temporal regions are important for visual object recognition and these regional cerebral blood flow changes are associated with inappropriate visual processing and are responsible for nonpsychotic visual hallucinations in PD.

Main Effects of Diagnoses, Brain Regions, and their Interaction Effects for Cerebral Metabolites in Bipolar and Unipolar Depressive Disorders

NASA Astrophysics Data System (ADS)

Tan, Hai-Zhu; Li, Hui; Liu, Chen-Feng; Guan, Ji-Tian; Guo, Xiao-Bo; Wen, Can-Hong; Ou, Shao-Min; Zhang, Yin-Nan; Zhang, Jie; Xu, Chong-Tao; Shen, Zhi-Wei; Wu, Ren-Hua; Wang, Xue-Qin

2016-11-01

Previous studies suggested patients with bipolar depressive disorder (BDd) or unipolar depressive disorder (UDd) have cerebral metabolites abnormalities. These abnormalities may stem from multiple sub-regions of gray matter in brain regions. Thirteen BDd patients, 20 UDd patients and 20 healthy controls (HC) were enrolled to investigate these abnormalities. Absolute concentrations of 5 cerebral metabolites (glutamate-glutamine (Glx), N-acetylaspartate (NAA), choline (Cho), myo-inositol (mI), creatine (Cr), parietal cortex (PC)) were measured from 4 subregions (the medial frontal cortex (mPFC), anterior cingulate cortex (ACC), posterior cingulate cortex (PCC), and parietal cortex (PC)) of gray matter. Main and interaction effects of cerebral metabolites across subregions of gray matter were evaluated. For example, the Glx was significantly higher in BDd compared with UDd, and so on. As the interaction analyses showed, some interaction effects existed. The concentrations of BDds’ Glx, Cho, Cr in the ACC and HCs’ mI and Cr in the PC were higher than that of other interaction effects. In addition, the concentrations of BDds’ Glx and Cr in the PC and HCs’ mI in the ACC were statistically significant lower than that of other interaction effects. These findings point to region-related abnormalities of cerebral metabolites across subjects with BDd and UDd.

Main Effects of Diagnoses, Brain Regions, and their Interaction Effects for Cerebral Metabolites in Bipolar and Unipolar Depressive Disorders.

PubMed

Tan, Hai-Zhu; Li, Hui; Liu, Chen-Feng; Guan, Ji-Tian; Guo, Xiao-Bo; Wen, Can-Hong; Ou, Shao-Min; Zhang, Yin-Nan; Zhang, Jie; Xu, Chong-Tao; Shen, Zhi-Wei; Wu, Ren-Hua; Wang, Xue-Qin

2016-11-21

Previous studies suggested patients with bipolar depressive disorder (BDd) or unipolar depressive disorder (UDd) have cerebral metabolites abnormalities. These abnormalities may stem from multiple sub-regions of gray matter in brain regions. Thirteen BDd patients, 20 UDd patients and 20 healthy controls (HC) were enrolled to investigate these abnormalities. Absolute concentrations of 5 cerebral metabolites (glutamate-glutamine (Glx), N-acetylaspartate (NAA), choline (Cho), myo-inositol (mI), creatine (Cr), parietal cortex (PC)) were measured from 4 subregions (the medial frontal cortex (mPFC), anterior cingulate cortex (ACC), posterior cingulate cortex (PCC), and parietal cortex (PC)) of gray matter. Main and interaction effects of cerebral metabolites across subregions of gray matter were evaluated. For example, the Glx was significantly higher in BDd compared with UDd, and so on. As the interaction analyses showed, some interaction effects existed. The concentrations of BDds' Glx, Cho, Cr in the ACC and HCs' mI and Cr in the PC were higher than that of other interaction effects. In addition, the concentrations of BDds' Glx and Cr in the PC and HCs' mI in the ACC were statistically significant lower than that of other interaction effects. These findings point to region-related abnormalities of cerebral metabolites across subjects with BDd and UDd.

A broadband continuous-wave multichannel near-infrared system for measuring regional cerebral blood flow and oxygen consumption in newborn piglets.

PubMed

Diop, Mamadou; Elliott, Jonathan T; Tichauer, Kenneth M; Lee, Ting-Yim; St Lawrence, Keith

2009-05-01

Near-infrared spectroscopy (NIRS) is a promising technique for assessing brain function in newborns, particularly due to its portability and sensitivity to cerebral hemodynamics and oxygenation. Methods for measuring cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO(2)) have been developed based on broadband continuous-wave NIRS. However, broadband NIRS apparatus typically have only one detection channel, which limits their applicability to measuring regional CBF and CMRO(2). In this study, a relatively simple multiplexing approach based on electronically controlled mechanical shutters is proposed to expand the detection capabilities from one to eight channels. The tradeoff is an increase in the sampling interval; however, this has negligible effects on CBF measurements for intervals less than or equal to 1 s. The ability of the system to detect focal brain injury was demonstrated in piglets by injecting endothelin-1 (ET-1) into the cerebral cortex. For validation, CBF was independently measured by computed tomography (CT) perfusion. The average reduction in CBF from the source-detector pair that interrogated the injured region was 51%+/-9%, which was in good agreement with the CBF reduction measured by CT perfusion (55%+/-5%). No significant changes in regional CMRO(2) were observed. The average regional differential pathlength prior to ET-1 injection was 8.4+/-0.2 cm (range of 7.1-9.6 cm) and did not significantly change after the injury.

Regional vulnerability of longitudinal cortical association connectivity: Associated with structural network topology alterations in preterm children with cerebral palsy.

PubMed

Ceschin, Rafael; Lee, Vince K; Schmithorst, Vince; Panigrahy, Ashok

2015-01-01

Preterm born children with spastic diplegia type of cerebral palsy and white matter injury or periventricular leukomalacia (PVL), are known to have motor, visual and cognitive impairments. Most diffusion tensor imaging (DTI) studies performed in this group have demonstrated widespread abnormalities using averaged deterministic tractography and voxel-based DTI measurements. Little is known about structural network correlates of white matter topography and reorganization in preterm cerebral palsy, despite the availability of new therapies and the need for brain imaging biomarkers. Here, we combined novel post-processing methodology of probabilistic tractography data in this preterm cohort to improve spatial and regional delineation of longitudinal cortical association tract abnormalities using an along-tract approach, and compared these data to structural DTI cortical network topology analysis. DTI images were acquired on 16 preterm children with cerebral palsy (mean age 5.6 ± 4) and 75 healthy controls (mean age 5.7 ± 3.4). Despite mean tract analysis, Tract-Based Spatial Statistics (TBSS) and voxel-based morphometry (VBM) demonstrating diffusely reduced fractional anisotropy (FA) reduction in all white matter tracts, the along-tract analysis improved the detection of regional tract vulnerability. The along-tract map-structural network topology correlates revealed two associations: (1) reduced regional posterior-anterior gradient in FA of the longitudinal visual cortical association tracts (inferior fronto-occipital fasciculus, inferior longitudinal fasciculus, optic radiation, posterior thalamic radiation) correlated with reduced posterior-anterior gradient of intra-regional (nodal efficiency) metrics with relative sparing of frontal and temporal regions; and (2) reduced regional FA within frontal-thalamic-striatal white matter pathways (anterior limb/anterior thalamic radiation, superior longitudinal fasciculus and cortical spinal tract) correlated with

Relationship between white matter lesions and regional cerebral blood flow changes during longitudinal follow up in Alzheimer's disease.

PubMed

Hanaoka, Takuya; Kimura, Noriyuki; Aso, Yasuhiro; Takemaru, Makoto; Kimura, Yuki; Ishibashi, Masato; Matsubara, Etsuro

2016-07-01

The aim of the present study was to evaluate the relationship between baseline white matter lesions (WML) and changes in regional cerebral blood flow during longitudinal follow up of patients with Alzheimer's disease (AD). A total of 38 patients with AD were included in the study (16 men, 22 women; mean age 77.8 years). All patients were evaluated using the Mini-Mental State Examination and brain perfusion single-photon emission computed tomography at baseline with an approximately 2-year follow up. The patients were divided into two subgroups according to the presence of WML on magnetic resonance imaging. Single-photon emission computed tomography data were analyzed using a voxel-by-voxel group analysis with Statistical Parametric Mapping 8 and region of interest analysis using FineSRT. Changes in Mini-Mental State Examination scores and regional cerebral blood flow were analyzed using the Wilcoxon signed-rank test. Mean Mini-Mental State Examination scores in AD patients with WML significantly decreased from 19.4 ± 4.8 to 15.5 ± 6.5 (P = 0.003). Statistical Parametric Mapping 8 and FineSRT analysis showed more severe and widespread regional cerebral blood flow reduction, mainly in the frontal and mesial temporal regions in AD patients with WML compared with those without WML. Baseline WML could predict a rapid progression of cognitive and brain functional impairment during longitudinal follow up in AD. Geriatr Gerontol Int 2016; 16: 836-842. © 2015 Japan Geriatrics Society.

A broadband continuous-wave multichannel near-infrared system for measuring regional cerebral blood flow and oxygen consumption in newborn piglets

NASA Astrophysics Data System (ADS)

Diop, Mamadou; Elliott, Jonathan T.; Tichauer, Kenneth M.; Lee, Ting-Yim; St. Lawrence, Keith

2009-05-01

Near-infrared spectroscopy (NIRS) is a promising technique for assessing brain function in newborns, particularly due to its portability and sensitivity to cerebral hemodynamics and oxygenation. Methods for measuring cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO2) have been developed based on broadband continuous-wave NIRS. However, broadband NIRS apparatus typically have only one detection channel, which limits their applicability to measuring regional CBF and CMRO2. In this study, a relatively simple multiplexing approach based on electronically controlled mechanical shutters is proposed to expand the detection capabilities from one to eight channels. The tradeoff is an increase in the sampling interval; however, this has negligible effects on CBF measurements for intervals less than or equal to 1 s. The ability of the system to detect focal brain injury was demonstrated in piglets by injecting endothelin-1 (ET-1) into the cerebral cortex. For validation, CBF was independently measured by computed tomography (CT) perfusion. The average reduction in CBF from the source-detector pair that interrogated the injured region was 51%±9%, which was in good agreement with the CBF reduction measured by CT perfusion (55%±5%). No significant changes in regional CMRO2 were observed. The average regional differential pathlength prior to ET-1 injection was 8.4±0.2 cm (range of 7.1-9.6 cm) and did not significantly change after the injury.

Regional cerebral blood flow measurement with intravenous ( sup 15 O)water bolus and ( sup 18 F)fluoromethane inhalation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Herholz, K.; Pietrzyk, U.; Wienhard, K.

1989-09-01

In 20 patients with ischemic cerebrovascular disease, classic migraine, or angiomas, we compared paired dynamic positron emission tomographic measurements of regional cerebral blood flow using both ({sup 15}O)water and ({sup 18}F)fluoromethane as tracers. Cerebral blood flow was also determined according to the autoradiographic technique with a bolus injection of ({sup 15}O)water. There were reasonable overall correlations between dynamic ({sup 15}O)water and ({sup 18}F)fluoromethane values for cerebral blood flow (r = 0.82) and between dynamic and autoradiographic ({sup 15}O)water values for cerebral blood flow (r = 0.83). We found a close correspondence between abnormal pathologic findings and visually evaluated cerebral bloodmore » flow tomograms obtained with the two tracers. On average, dynamic ({sup 15}O)water cerebral blood flow was 6% lower than that measured with ({sup 18}F)fluoromethane. There also was a general trend toward a greater underestimation with ({sup 15}O)water in high-flow areas, particularly in hyperemic areas, probably due to incomplete first-pass extraction of ({sup 15}O)water. Underestimation was not detected in low-flow areas or in the cerebellum. Absolute cerebral blood flow values were less closely correlated between tracers and techniques than cerebral blood flow patterns. The variability of the relation between absolute flow values was probably caused by confounding effects of the variation in the circulatory delay time. The autoradiographic technique was most sensitive to this type error.« less

Glibenclamide Produces Region-Dependent Effects on Cerebral Edema in a Combined Injury Model of Traumatic Brain Injury and Hemorrhagic Shock in Mice.

PubMed

Jha, Ruchira M; Molyneaux, Bradley J; Jackson, Travis C; Wallisch, Jessica S; Park, Seo-Young; Poloyac, Samuel; Vagni, Vincent A; Janesko-Feldman, Keri L; Hoshitsuki, Keito; Minnigh, M Beth; Kochanek, Patrick M

2018-06-06

Cerebral edema is critical to morbidity/mortality in traumatic brain injury (TBI) and is worsened by hypotension. Glibenclamide may reduce cerebral edema by inhibiting sulfonylurea receptor-1 (Sur1); its effect on diffuse cerebral edema exacerbated by hypotension/resuscitation is unknown. We aimed to determine if glibenclamide improves pericontusional and/or diffuse edema in controlled cortical impact (CCI) (5m/sec, 1 mm depth) plus hemorrhagic shock (HS) (35 min), and compare its effects in CCI alone. C57BL/6 mice were divided into five groups (n = 10/group): naïve, CCI+vehicle, CCI+glibenclamide, CCI+HS+vehicle, and CCI+HS+glibenclamide. Intravenous glibenclamide (10 min post-injury) was followed by a subcutaneous infusion for 24 h. Brain edema in injured and contralateral hemispheres was subsequently quantified (wet-dry weight). This protocol brain water (BW) = 80.4% vehicle vs. 78.3% naïve, p < 0.01) but was not reduced by glibenclamide (I%BW = 80.4%). Ipsilateral edema also developed in CCI alone (I%BW = 80.2% vehicle vs. 78.3% naïve, p < 0.01); again unaffected by glibenclamide (I%BW = 80.5%). Contralateral (C) %BW in CCI+HS was increased in vehicle (78.6%) versus naive (78.3%, p = 0.02) but unchanged in CCI (78.3%). At 24 h, glibenclamide treatment in CCI+HS eliminated contralateral cerebral edema (C%BW = 78.3%) with no difference versus naïve. By 72 h, contralateral cerebral edema had resolved (C%BW = 78.5 ± 0.09% vehicle vs. 78.3 ± 0.05% naïve). Glibenclamide decreased 24 h contralateral cerebral edema in CCI+HS. This beneficial effect merits additional exploration in the important setting of TBI with polytrauma, shock, and resuscitation. Contralateral edema did not develop in CCI alone. Surprisingly, 24 h of glibenclamide treatment failed to decrease ipsilateral edema in either model. Interspecies dosing differences versus prior studies may play an important role in these findings

Increased regional cerebral glucose uptake in an APP/PS1 model of Alzheimer’s disease

PubMed Central

Poisnel, Géraldine; Hérard, Anne-Sophie; El Tannir El Tayara, Nadine; Bourrin, Emmanuel; Volk, Andreas; Kober, Frank; Delatour, Benoit; Delzescaux, Thierry; Debeir, Thomas; Rooney, Thomas; Benavides, Jésus; Hantraye, Philippe; Dhenain, Marc

2013-01-01

Alzheimer’s disease (AD), the most common age-related neurodegenerative disorder, is characterized by the invariant cerebral accumulation of β-amyloid peptide. This event occurs early in the disease process. In humans, [18F]-Fluoro-2-deoxy-D-Glucose-Positron Emission Tomography ([18F]-FDG-PET) is largely used to follow-up in vivo cerebral glucose utilisation (CGU) and brain metabolism modifications associated to the AD pathology. Here, [18F]-FDG-PET was used to study age-related changes of CGU under resting conditions in 3, 6 and 12-month-old APPSweLon/PS1M146L, a mouse model of amyloidosis. We showed an age-dependent increase of glucose uptake in several brain regions of APP/PS1 mice but not in control animals and a higher [18F]-FDG uptake in the cortex and the hippocampus of 12-month-old APP/PS1 mice as compared to age-matched control mice. We then developed a method of 3D-microscopic autoradiography to evaluate glucose uptake at the level of amyloid plaques and showed an increased glucose uptake close to the plaques rather than in amyloid-free cerebral tissues. These data suggest a macroscopic and microscopic reorganisation of glucose uptake in relation to cerebral amyloidosis. PMID:22079157

Caffeine and human cerebral blood flow: A positron emission tomography study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cameron, O.G.; Modell, J.G.; Hariharan, M.

1990-01-01

Positron emission tomography (PET) was used to quantify the effect of caffeine on whole brain and regional cerebral blood flow (CBF) in humans. A mean dose of 250 mg of caffeine produced approximately a 30% decrease in whole brain CBF; regional differences in caffeine effect were not observed. Pre-caffeine CBF strongly influenced the magnitude of the caffeine-induced decrease. Caffeine decreased p{sub a}CO{sub 2} and increased systolic blood pressure significantly; the change in p{sub a}CO{sub 2} did not account for the change in CBF. Smaller increases in diastolic blood pressure, heart rate, plasma epinephrine and norepinephrine, and subjectively reported anxiety weremore » also observed.« less

Autonomic neural control of dynamic cerebral autoregulation in humans

NASA Technical Reports Server (NTRS)

Zhang, Rong; Zuckerman, Julie H.; Iwasaki, Kenichi; Wilson, Thad E.; Crandall, Craig G.; Levine, Benjamin D.

2002-01-01

BACKGROUND: The purpose of the present study was to determine the role of autonomic neural control of dynamic cerebral autoregulation in humans. METHODS AND RESULTS: We measured arterial pressure and cerebral blood flow (CBF) velocity in 12 healthy subjects (aged 29+/-6 years) before and after ganglion blockade with trimethaphan. CBF velocity was measured in the middle cerebral artery using transcranial Doppler. The magnitude of spontaneous changes in mean blood pressure and CBF velocity were quantified by spectral analysis. The transfer function gain, phase, and coherence between these variables were estimated to quantify dynamic cerebral autoregulation. After ganglion blockade, systolic and pulse pressure decreased significantly by 13% and 26%, respectively. CBF velocity decreased by 6% (P<0.05). In the very low frequency range (0.02 to 0.07 Hz), mean blood pressure variability decreased significantly (by 82%), while CBF velocity variability persisted. Thus, transfer function gain increased by 81%. In addition, the phase lead of CBF velocity to arterial pressure diminished. These changes in transfer function gain and phase persisted despite restoration of arterial pressure by infusion of phenylephrine and normalization of mean blood pressure variability by oscillatory lower body negative pressure. CONCLUSIONS: These data suggest that dynamic cerebral autoregulation is altered by ganglion blockade. We speculate that autonomic neural control of the cerebral circulation is tonically active and likely plays a significant role in the regulation of beat-to-beat CBF in humans.

Feasibility of Quantifying Arterial Cerebral Blood Volume Using Multiphase Alternate Ascending/Descending Directional Navigation (ALADDIN).

PubMed

Kim, Ki Hwan; Choi, Seung Hong; Park, Sung-Hong

2016-01-01

Arterial cerebral blood volume (aCBV) is associated with many physiologic and pathologic conditions. Recently, multiphase balanced steady state free precession (bSSFP) readout was introduced to measure labeled blood signals in the arterial compartment, based on the fact that signal difference between labeled and unlabeled blood decreases with the number of RF pulses that is affected by blood velocity. In this study, we evaluated the feasibility of a new 2D inter-slice bSSFP-based arterial spin labeling (ASL) technique termed, alternate ascending/descending directional navigation (ALADDIN), to quantify aCBV using multiphase acquisition in six healthy subjects. A new kinetic model considering bSSFP RF perturbations was proposed to describe the multiphase data and thus to quantify aCBV. Since the inter-slice time delay (TD) and gap affected the distribution of labeled blood spins in the arterial and tissue compartments, we performed the experiments with two TDs (0 and 500 ms) and two gaps (300% and 450% of slice thickness) to evaluate their roles in quantifying aCBV. Comparison studies using our technique and an existing method termed arterial volume using arterial spin tagging (AVAST) were also separately performed in five subjects. At 300% gap or 500-ms TD, significant tissue perfusion signals were demonstrated, while tissue perfusion signals were minimized and arterial signals were maximized at 450% gap and 0-ms TD. ALADDIN has an advantage of visualizing bi-directional flow effects (ascending/descending) in a single experiment. Labeling efficiency (α) of inter-slice blood flow effects could be measured in the superior sagittal sinus (SSS) (20.8±3.7%.) and was used for aCBV quantification. As a result of fitting to the proposed model, aCBV values in gray matter (1.4-2.3 mL/100 mL) were in good agreement with those from literature. Our technique showed high correlation with AVAST, especially when arterial signals were accentuated (i.e., when TD = 0 ms) (r = 0

The role of regional nerve block anesthesia for carotid endarterectomy: an experimental comparison with previous series with the use of general anesthesia and barbiturates for cerebral protection.

PubMed

Agrifoglio, G; Agus, G B; Bonalumi, F; Costantini, A; Carlesi, R

1987-01-01

A retrospective analysis was performed on a consecutive series of 60 cases divided into two groups given carotid endarterectomy (C.E.) for atherosclerotic disease. In the first group general anesthesia and barbiturate cerebral protection were employed; in group two, loco-regional anesthesia. Indications and risk factors were similar in the two groups; the surgical procedure was identical. The differences in the results are reported and factors contributing to cerebral protection or reduction in the risk of stroke are analyzed. The analysis indicates that loco-regional anesthesia for C.E. is a reliable method for detecting cerebral ischemia and guaranteeing cerebral protection by means of a temporary shunt when strictly necessary.

Increasing the Contrast-to-Noise Ratio of MRI Signals for Regional Assessment of Dynamic Cerebral Autoregulation.

PubMed

Jara, José L; Saeed, Nazia P; Panerai, Ronney B; Robinson, Thompson G

2018-01-01

To devise an appropriate measure of the quality of a magnetic resonance imaging (MRI) signal for the assessment of dynamic cerebral autoregulation, and propose simple strategies to improve its quality. Magnetic resonance images of 11 healthy subjects were scanned during a transient decrease in arterial blood pressure (BP). Mean signals were extracted from non-overlapping brain regions for each image. An ad-hoc contrast-to-noise ratio (CNR) was used to evaluate the quality of these regional signals. Global mean signals were obtained by averaging the set of regional signals resulting after applying a Hampel filter and discarding a proportion of the lower quality component signals. Significant improvements in CNR values of global mean signals were obtained, whilst maintaining significant correlation with the original ones. A Hampel filter with a small moving window and a low rejection threshold combined with a selection of the 50% component signals seems a recommendable option. This work has demonstrated the possibility of improving the quality of MRI signals acquired during transient drops in BP. This approach needs validation at a voxel level, which could help to consolidate MRI as a technological alternative to the standard techniques for the study of cerebral autoregulation.

Multiple Transmitter Receptors in Regions and Layers of the Human Cerebral Cortex

PubMed Central

Zilles, Karl; Palomero-Gallagher, Nicola

2017-01-01

We measured the densities (fmol/mg protein) of 15 different receptors of various transmitter systems in the supragranular, granular and infragranular strata of 44 areas of visual, somatosensory, auditory and multimodal association systems of the human cerebral cortex. Receptor densities were obtained after labeling of the receptors using quantitative in vitro receptor autoradiography in human postmortem brains. The mean density of each receptor type over all cortical layers and of each of the three major strata varies between cortical regions. In a single cortical area, the multi-receptor fingerprints of its strata (i.e., polar plots, each visualizing the densities of multiple different receptor types in supragranular, granular or infragranular layers of the same cortical area) differ in shape and size indicating regional and laminar specific balances between the receptors. Furthermore, the three strata are clearly segregated into well definable clusters by their receptor fingerprints. Fingerprints of different cortical areas systematically vary between functional networks, and with the hierarchical levels within sensory systems. Primary sensory areas are clearly separated from all other cortical areas particularly by their very high muscarinic M2 and nicotinic α4β2 receptor densities, and to a lesser degree also by noradrenergic α2 and serotonergic 5-HT2 receptors. Early visual areas of the dorsal and ventral streams are segregated by their multi-receptor fingerprints. The results are discussed on the background of functional segregation, cortical hierarchies, microstructural types, and the horizontal (layers) and vertical (columns) organization in the cerebral cortex. We conclude that a cortical column is composed of segments, which can be assigned to the cortical strata. The segments differ by their patterns of multi-receptor balances, indicating different layer-specific signal processing mechanisms. Additionally, the differences between the strata-and area

Regional cerebral blood flow in childhood headache

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roach, E.S.; Stump, D.A.

1989-06-01

Regional cerebral blood flow (rCBF) was measured in 16 cranial regions in 23 children and adolescents with frequent headaches using the non-invasive Xenon-133 inhalation technique. Blood flow response to 5% carbon dioxide (CO2) was also determined in 21 patients, while response to 50% oxygen was measured in the two patients with hemoglobinopathy. Included were 10 patients with a clinical diagnosis of migraine, 4 with musculoskeletal headaches, and 3 with features of both types. Also studied were 2 patients with primary thrombocythemia, 2 patients with hemoglobinopathy and headaches, 1 patient with polycythemia, and 1 with headaches following trauma. With two exceptions,more » rCBF determinations were done during an asymptomatic period. Baseline rCBF values tended to be higher in these young patients than in young adults done in our laboratory. Localized reduction in the expected blood flow surge after CO2 inhalation, most often noted posteriorly, was seen in 8 of the 13 vascular headaches, but in none of the musculoskeletal headache group. Both patients with primary thrombocythemia had normal baseline flow values and altered responsiveness to CO2 similar to that seen in migraineurs; thus, the frequently reported headache and transient neurologic signs with primary thrombocythemia are probably not due to microvascular obstruction as previously suggested. These data support the concept of pediatric migraine as a disorder of vasomotor function and also add to our knowledge of normal rCBF values in younger patients. Demonstration of altered vasomotor reactivity to CO2 could prove helpful in children whose headache is atypical.« less

Reference ranges for regional cerebral tissue oxygen saturation and fractional oxygen extraction in neonates during immediate transition after birth.

PubMed

Pichler, Gerhard; Binder, Corinna; Avian, Alexander; Beckenbach, Elisabeth; Schmölzer, Georg M; Urlesberger, Berndt

2013-12-01

To define reference ranges for regional cerebral tissue oxygen saturation (crSO2) and regional cerebral fractional tissue oxygen extraction (cFTOE) during the first 15 minutes after birth in neonates requiring no medical support. The crSO2 was measured using near infrared spectroscopy (Invos 5100 cerebral/somatic oximeter monitor; Somanetics Corp, Troy, Michigan) during the first 15 minutes after birth for term and preterm neonates. The near infrared spectroscopy sensor was placed on the left forehead. Peripheral oxygen saturation and heart rate were continuously measured by pulse oximetry, and cFTOE was calculated. Neonates were excluded if they required any medical support. A total of 381 neonates were included: 82 term neonates after vaginal delivery, 272 term neonates after cesarean delivery, and 27 preterm neonates after cesarean delivery. In all neonates, median (10th-90th percentiles) crSO2 was 41% (23-64) at 2 minutes, 68% (45-85) at 5 minutes, 79% (65-90) at 10 minutes, and 77% (63-89) at 15 minutes of age. In all neonates, median (10th-90th percentiles) cFTOE was 33% (11-70) at 2 minutes, 21% (6-45) at 5 minutes, 15% (5-31) at 10 minutes, and 18% (7-34) at 15 minutes of age. We report reference ranges of crSO2 and cFTOE in neonates requiring no medical support during transition immediately after birth. The use of cerebral oxygenation monitoring and use of these reference ranges in neonates during transition may help to guide oxygen delivery and avoid cerebral hypo-oxygenation and hyperoxygenation. Copyright © 2013 Mosby, Inc. All rights reserved.

Regional Cerebral Oxygen Saturation Level Predicts 30-Day Mortality Rate After Left Ventricular Assist Device Surgery.

PubMed

Ghosal, Soutik; Trivedi, Jaimin; Chen, James; Rogers, Michael P; Cheng, Allen; Slaughter, Mark S; Kong, Maiying; Huang, Jiapeng

2018-06-01

Left ventricular assist device (LVAD) surgery is complex, high risk, and expensive. The authors' hypothesis is baseline regional cerebral oxygen saturation (rSO 2 ) might be a predictor of postoperative clinical outcomes. Retrospective review of 210 consecutive continuous flow LVAD patients between 2008 and 2014. The primary measure is 30-day mortality rate and secondary measures include modified major adverse cardiocerebral events (MACE), length of stay (LOS), and intensive care unit (ICU) stay. Multiple logistic regression models were applied to examine if a binary outcome variable, such as 30-day mortality and MACE, is associated with rSO 2 at baseline. Log-linear model was used to examine whether LOS or ICU stay hours is associated with rSO 2 at baseline. Single institution, academic hospital. Patients who received LVAD surgery ​at Jewish Hospital, Louisville, KY. All patients received LVAD surgery. Cerebral oximetry monitoring was used in both the preoperative and intraoperative periods. The authors found that higher rSO 2 at baseline is associated with lower 30-day mortality with an odds ratio of 0.94 and 95% confidence interval (0.888, 0.995) for every 1% increase of rSO 2 . For secondary outcomes, baseline rSO 2 was not significantly associated with MACE, requirement for postoperative renal failure/dialysis, reoperation for bleeding, and LOS or ICU hours. Regional cerebral oxygen saturation levels at baseline are significantly associated with 30-day mortality after LVAD surgeries. Copyright © 2017 Elsevier Inc. All rights reserved.

Effects of ischemic preconditioning on PDGF-BB expression in the gerbil hippocampal CA1 region following transient cerebral ischemia

PubMed Central

Lee, Jae-Chul; Kim, Yang Hee; Lee, Tae-Kyeong; Kim, In Hye; Cho, Jeong Hwi; Cho, Geum-Sil; Shin, Bich-Na; Park, Joon Ha; Ahn, Ji Hyeon; Shin, Myoung Cheol; Cho, Jun Hwi; Kang, Il Jun; Won, Moo-Ho; Seo, Jeong Yeol

2017-01-01

Ischemic preconditioning (IPC) is induced by exposure to brief durations of transient ischemia, which results in ischemic tolerance to a subsequent longer or lethal period of ischemia. In the present study, the effects of IPC (2 min of transient cerebral ischemia) were examined on immunoreactivity of platelet-derived growth factor (PDGF)-BB and on neuroprotection in the gerbil hippocampal CA1 region following lethal transient cerebral ischemia (LTCI; 5 min of transient cerebral ischemia). IPC was subjected to a 2-min sublethal ischemia and a LTCI was given 5-min transient ischemia. The animals in all of the groups were given recovery times of 1, 2 and 5 days and change in PDGF-BB immunoreactivity was examined as was the neuronal damage/death in the hippocampus induced by LTCI. LTCI induced a significant loss of pyramidal neurons in the hippocampal CA1 region 5 days after LTCI, and significantly decreased PDGF-BB immunoreactivity in the CA1 pyramidal neurons from day 1 after LTCI. Conversely, IPC effectively protected the CA1 pyramidal neurons from LTCI and increased PDGF-BB immunoreactivity in the CA1 pyramidal neurons post-LTCI. In conclusion, the results demonstrated that LTCI significantly altered PDGF-BB immunoreactivity in pyramidal neurons in the hippocampal CA1 region, whereas IPC increased the immunoreactivity. These findings indicated that PDGF-BB may be associated with IPC-mediated neuroprotection. PMID:28627606

Cerebral hematocrit decreases with hemodynamic compromise in carotid artery occlusion: a PET study.

PubMed

Yamauchi, H; Fukuyama, H; Nagahama, Y; Katsumi, Y; Okazawa, H

1998-01-01

This study investigated whether in patients with internal carotid artery occlusion the regional cerebral hematocrit correlates with cerebral hemodynamics or metabolic state and, if so, how the regional cerebral hematocrit changes in the hemodynamically compromised region. We used positron emission tomography to study seven patients with unilateral internal carotid artery occlusion and no cortical infarction in the chronic stage. The distributions of red blood cell and plasma volumes were assessed using oxygen-15-labeled carbon monoxide and copper-62-labeled human serum albumin-dithiosemicarbazone tracers, respectively. The calculated hematocrit value was compared with the hemodynamic and metabolic parameters measured with the oxygen-15 steady-state technique. In the cerebral cortex, the value of the cerebral hematocrit varied but was correlated with the hemodynamic and metabolic status. Stepwise regression analysis revealed that the large vessel hematocrit, the cerebral metabolic rate of oxygen, and the cerebral blood flow or the oxygen extraction fraction accounted for a significant proportion of variance of the cerebral hematocrit. The oxygen extraction fraction and the cerebral metabolic rate of oxygen negatively correlated with the cerebral hematocrit, whereas the cerebral blood flow correlated positively: patients with reduced blood supply relative to metabolic demand (decreased blood flow with increased oxygen extraction fraction) showed low hematocrit values. In carotid artery occlusion in the chronic stage, regional cerebral hematocrit may vary according to cerebral hemodynamics and metabolic status. Regional cerebral hematocrit may decrease with hemodynamic compromise unless oxygen metabolism concomitantly decreases.

Usefulness of Deep Hypothermic Circulatory Arrest and Regional Cerebral Perfusion in Children

PubMed Central

Guo, Zheng; Hu, Ren-Jie; Zhu, De-Ming; Zhu, Zhong-Qun; Zhang, Hai-Bo

2013-01-01

To compare the safety and usefulness of deep hypothermic circulatory arrest (DHCA) and regional cerebral perfusion (RCP) during pediatric open heart surgery. Between January 1, 2004 and September 30, 2012, 1250 children with congenital cardiac defect underwent corrective operation with the DHCA or RCP technique in the Shanghai Children's Medical Center. Of them, 947 cases underwent the operation with the aid of DHCA (DHCA group), and 303 cases with RCP (RCP group). The mean DHCA time was 30.64±15.81 (7–63) minutes and mean RCP time was 36.18±12.86 (10–82) minutes. The mortality rate was 7.18% (68/947) and 6.60% (20/30) in two groups, respectively. The postoperative incidences of temporary and permanent neurological dysfunction were 6.23% (59/947) in the DHCA group and 2.64% (8/303) in the RCP group (p<0.01). The incidence of other complications such as low cardiac output, renal dysfunction, and lung issues are similar in both groups. RCP is a reliable technique for cerebral protection and it facilitates time-consuming corrected procedures for complex congenital cardiac defect repair procedures. PMID:24066266

Cerebral Apolipoprotein-D Is Hypoglycosylated Compared to Peripheral Tissues and Is Variably Expressed in Mouse and Human Brain Regions.

PubMed

Li, Hongyun; Ruberu, Kalani; Karl, Tim; Garner, Brett

2016-01-01

Recent studies have shown that cerebral apoD levels increase with age and in Alzheimer's disease (AD). In addition, loss of cerebral apoD in the mouse increases sensitivity to lipid peroxidation and accelerates AD pathology. Very little data are available, however, regarding the expression of apoD protein levels in different brain regions. This is important as both brain lipid peroxidation and neurodegeneration occur in a region-specific manner. Here we addressed this using western blotting of seven different regions (olfactory bulb, hippocampus, frontal cortex, striatum, cerebellum, thalamus and brain stem) of the mouse brain. Our data indicate that compared to most brain regions, the hippocampus is deficient in apoD. In comparison to other major organs and tissues (liver, spleen, kidney, adrenal gland, heart and skeletal muscle), brain apoD was approximately 10-fold higher (corrected for total protein levels). Our analysis also revealed that brain apoD was present at a lower apparent molecular weight than tissue and plasma apoD. Utilising peptide N-glycosidase-F and neuraminidase to remove N-glycans and sialic acids, respectively, we found that N-glycan composition (but not sialylation alone) were responsible for this reduction in molecular weight. We extended the studies to an analysis of human brain regions (hippocampus, frontal cortex, temporal cortex and cerebellum) where we found that the hippocampus had the lowest levels of apoD. We also confirmed that human brain apoD was present at a lower molecular weight than in plasma. In conclusion, we demonstrate apoD protein levels are variable across different brain regions, that apoD levels are much higher in the brain compared to other tissues and organs, and that cerebral apoD has a lower molecular weight than peripheral apoD; a phenomenon that is due to the N-glycan content of the protein.

Impairment of facial recognition in patients with right cerebral infarcts quantified by computer aided "morphing".

PubMed Central

Rösler, A; Lanquillon, S; Dippel, O; Braune, H J

1997-01-01

OBJECTIVE: To investigate where facial recognition is located anatomically and to establish whether there is a graded transition from unimpaired recognition of faces to complete prosopagnosia after infarctions in the territory of the middle cerebral artery. METHODS: A computerised morphing program was developed which shows 30 frames gradually changing from portrait photographs of unfamiliar persons to those of well known persons. With a standardised protocol, 31 patients with right and left sided infarctions in the territory of the middle cerebral artery and an age and sex matched control group were compared by non-parametric tests. RESULTS AND CONCLUSION: Facial recognition in patients with right sided lesions was significantly impaired compared with controls and with patients with left sided lesions. A graded impairment in facial recognition in patients with right sided ischaemic infarcts in the territory of the middle cerebral artery seems to exist. Images PMID:9069481

Cerebral Effect of Intratracheal Aerosolized Surfactant Versus Bolus Therapy in Preterm Lambs.

PubMed

Rey-Santano, Carmen; Mielgo, Victoria E; López-de-Heredia-y-Goya, Jon; Murgia, Xabier; Valls-i-Soler, Adolfo

2016-04-01

Aerosolization has been proposed as a useful alternative to rapid intratracheal instillation for the delivery of exogenous surfactant in neonatal respiratory distress syndrome. However, there is a lack of information regarding the likely safety of this new therapeutic approach for the neonatal brain. We aimed to compare the cerebral effects of aerosolized versus bolus surfactant administration in premature lambs with respiratory distress syndrome. Prospective randomized study. BioCruces Institute Animal Research Facility. Fourteen intensively monitored and mechanically ventilated preterm lambs. Preterm lambs were randomly assigned to receive intratracheal aerosolized surfactant or bolus surfactant. Brain hemodynamics (cerebral and regional cerebral blood flow) and cerebral oxygen metabolism (cerebral oxygen delivery, cerebral metabolic rate of oxygen, and oxygen extraction fraction) were measured every 30 minutes for 6 hours. We also performed cerebral biochemical and histological analysis. In preterm lambs with respiratory distress syndrome, cerebral blood flow, regional cerebral blood flow, cerebral oxygen delivery, and cerebral metabolic rate of oxygen increased significantly in the bolus surfactant group during the first 5 minutes, without changes in cerebral oxygen extraction fraction. By 60 minutes, all parameters had decreased in both groups, cerebral blood flow and regional cerebral blood flow (in inner and cerebellum brainstem regions) remaining higher in the bolus surfactant than in the aerosolized surfactant group. Overall, the impact of aerosol surfactant was not significantly different to that of bolus surfactant in terms of cerebral necrosis, edema, inflammation, hemorrhage, infarct, apoptosis, or oxidative stress. In preterm lambs with severe respiratory distress syndrome, aerosol surfactant administration seems to be as safe as bolus administration, showing more stable cerebral hemodynamics and cerebral oxygen metabolism to the same dose of

Single-photon tomographic determination of regional cerebral blood flow in epilepsy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bonte, F.J.; Devous, M.D. Sr.; Stokely, E.M.

Using a single-photon emission computed tomographic scanner (SPECT) the authors determined regional cerebral blood flow (rCBF) with inhaled xenon-133, a noninvasive procedure. Studies were performed in 40 normal individuals, and these were compared with rCBF determinations in 51 patients with seizure disorders. Although positive results were obtained in 15 of 16 patients with mass lesions, the group of principal interest comprised 25 patients suffering from ''temporal lobe'' epilepsy. Only one of these had a positive x-ray computed tomogram, but 16 had positive findings on rCBF study. These findings included increased local blood flow in the ictal state and reduced flowmore » interictally.« less

[Regional cerebral oxygen saturation as a marker of hemodynamic state following cardiac surgery].

PubMed

García-Hernández, J A; Aldemira-Liz, A; Martínez-López, A I; Cayuela, A; Charlo-Molina, M T; Cano-Franco, J; Loscertales-Abril, M

2013-10-01

Regional cerebral oxygen saturation (rSO₂) is a measure of the general state of perfusion and oxygenation. We aim to analyze the relationship between this and various hemodynamic and respiratory parameters. Forty-three patients, operated on between October 2011 and July 2012, were included in this prospective observational descriptive study. The following parameters were measured: mean arterial pressure, both arterial and central venous oxygen saturation and partial pressures of oxygen and carbon dioxide, and lactate levels. From these parameters, the oxygenation index and the oxygen extraction ratio were calculated. These measurements were studied to evaluate whether rSO₂ correlated significantly with the other parameters. The average age and weight of the patients were 27.3 months and 9.2 kg, respectively. The rSO₂ correlated positively with both central venous oxygen saturation (r=0.73, P<.01) and mean arterial pressure (r=0.59, P<.01), and negatively with the oxygen extraction ratio (r=-0.7, P<.01). No correlation was found with the respiratory parameters. Concordance analysis established an acceptable Kappa index (> 0.4) between the rSO₂ and central venous oxygen saturation, and between the rSO₂ and oxygen extraction ratio. Regional cerebral oxygen saturation correlates well with hemodynamic parameters - mean arterial pressure, venous saturation, and the tissue oxygen extraction. However, it does not correlate with respiratory parameters. Copyright © 2012 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.

Characterization of Atrophic Changes in the Cerebral Cortex Using Fractal Dimensional Analysis

PubMed Central

George, Anuh T.; Jeon, Tina; Hynan, Linda S.; Youn, Teddy S.; Kennedy, David N.; Dickerson, Bradford

2010-01-01

The purpose of this project is to apply a modified fractal analysis technique to high-resolution T1 weighted magnetic resonance images in order to quantify the alterations in the shape of the cerebral cortex that occur in patients with Alzheimer’s disease. Images were selected from the Alzheimer’s Disease Neuroimaging Initiative database (Control N=15, Mild-Moderate AD N=15). The images were segmented using a semi-automated analysis program. Four coronal and three axial profiles of the cerebral cortical ribbon were created. The fractal dimensions (Df) of the cortical ribbons were then computed using a box-counting algorithm. The mean Df of the cortical ribbons from AD patients were lower than age-matched controls on six of seven profiles. The fractal measure has regional variability which reflects local differences in brain structure. Fractal dimension is complementary to volumetric measures and may assist in identifying disease state or disease progression. PMID:20740072

Verbal fluency and positron emission tomographic mapping of regional cerebral glucose metabolism.

PubMed

Boivin, M J; Giordani, B; Berent, S; Amato, D A; Lehtinen, S; Koeppe, R A; Buchtel, H A; Foster, N L; Kuhl, D E

1992-06-01

Impairment in verbal fluency (VF) has been a consistently reported clinical feature of focal cerebral deficits in frontal and temporal regions. More recent behavioral activation studies with healthy control subjects using positron emission tomography (PET), however, have noted a negative correlation between performance on verbal fluency tasks and regional cortical activity. To see if this negative relationship extends to steady-state non-activation PET measures, thirty-three healthy adults were given a VF task within a day of their 18F-2-fluoro-2-deoxy-D-glucose PET scan. VF was found to correlate positively with left temporal cortical region metabolic activity but to correlate negatively with right and left frontal activity. VF was not correlated significantly with right temporal cortical metabolic activity. Some previous studies with normals using behavioral activation paradigms and PET have reported negative correlations between metabolic activity and cognitive performance similar to that reported here. An explanation for the disparate relationships that were observed between frontal and temporal brain areas and VF might be found in the mediation of different task demands by these separate locations, i.e., task planning and/or initiation by frontal regions and verbal memory by the left temporal area.

Higher serum glucose levels are associated with cerebral hypometabolism in Alzheimer regions.

PubMed

Burns, Christine M; Chen, Kewei; Kaszniak, Alfred W; Lee, Wendy; Alexander, Gene E; Bandy, Daniel; Fleisher, Adam S; Caselli, Richard J; Reiman, Eric M

2013-04-23

To investigate whether higher fasting serum glucose levels in cognitively normal, nondiabetic adults were associated with lower regional cerebral metabolic rate for glucose (rCMRgl) in brain regions preferentially affected by Alzheimer disease (AD). This is a cross-sectional study of 124 cognitively normal persons aged 64 ± 6 years with a first-degree family history of AD, including 61 APOEε4 noncarriers and 63 carriers. An automated brain mapping algorithm characterized and compared correlations between higher fasting serum glucose levels and lower [(18)F]-fluorodeoxyglucose-PET rCMRgl measurements. As predicted, higher fasting serum glucose levels were significantly correlated with lower rCMRgl and were confined to the vicinity of brain regions preferentially affected by AD. A similar pattern of regional correlations occurred in the APOEε4 noncarriers and carriers. Higher fasting serum glucose levels in cognitively normal, nondiabetic adults may be associated with AD pathophysiology. Findings suggest that the risk imparted by higher serum glucose levels may be independent of APOEε4 status. This study raises additional questions about the role of the metabolic process in the predisposition to AD and supports the possibility of targeting these processes in presymptomatic AD trials.

Cerebral and non-cerebral coenurosis: on the genotypic and phenotypic diversity of Taenia multiceps.

PubMed

Christodoulopoulos, Georgios; Dinkel, Anke; Romig, Thomas; Ebi, Dennis; Mackenstedt, Ute; Loos-Frank, Brigitte

2016-12-01

We characterised the causative agents of cerebral and non-cerebral coenurosis in livestock by determining the mitochondrial genotypes and morphological phenotypes of 52 Taenia multiceps isolates from a wide geographical range in Europe, Africa, and western Asia. Three studies were conducted: (1) a morphological comparison of the rostellar hooks of cerebral and non-cerebral cysts of sheep and goats, (2) a morphological comparison of adult worms experimentally produced in dogs, and (3) a molecular analysis of three partial mitochondrial genes (nad1, cox1, and 12S rRNA) of the same isolates. No significant morphological or genetic differences were associated with the species of the intermediate host. Adult parasites originating from cerebral and non-cerebral cysts differed morphologically, e.g. the shape of the small hooks and the distribution of the testes in the mature proglottids. The phylogenetic analysis of the mitochondrial haplotypes produced three distinct clusters: one cluster including both cerebral isolates from Greece and non-cerebral isolates from tropical and subtropical countries, and two clusters including cerebral isolates from Greece. The majority of the non-cerebral specimens clustered together but did not form a monophyletic group. No monophyletic groups were observed based on geography, although specimens from the same region tended to cluster. The clustering indicates high intraspecific diversity. The phylogenetic analysis suggests that all variants of T. multiceps can cause cerebral coenurosis in sheep (which may be the ancestral phenotype), and some variants, predominantly from one genetic cluster, acquired the additional capacity to produce non-cerebral forms in goats and more rarely in sheep.

Regional cerebral energy metabolism during intravenous anesthesia with etomidate, ketamine or thiopental

DOE Office of Scientific and Technical Information (OSTI.GOV)

Davis, D.W.

1987-01-01

Regional brain glucose utilization (rCMRglc) was measured in rats during steady-state levels of intravenous anesthesia to determine if alterations in brain function due to anesthesia could provide information on the mechanisms of anesthesia. Intravenous anesthetics from three different chemical classes were studied: etomidate, ketamine and thiopental. All rCMRglc experiments were conducted in freely moving rats in isolation chambers, with the use of (6-/sup 14/C) glucose and guantitative autoradiography. Etomidate caused a rostral-to-caudal gradient of depression of rCMRglc. The four doses of etomidate did not differ in their effects on energy metabolism. Sub-anesthetic (5 mg kg/sup -1/) and anesthetic (30 mgmore » kg /sup -1/) doses of ketamine produced markedly different patterns of behavior. Brain energy metabolism during the sub-anesthetic dose was stimulated in most regions, while the anesthetic dose selectively stimulated the hippocampus, leaving most brain regions unaffected. Thiopental produced a dose-dependent reduction of rCMRglc in all gray matter regions. No brain region was selectively affected. Comparison of the drug-specific alterations of cerebral energy metabolism suggests these anesthetics do not act through a common mechanism. The hypothesis that each acts by binding to specific cell membrane receptors is consistent with these observations.« less

Regional cerebral (18)FDG uptake during subarachnoid hemorrhage induced vasospasm.

PubMed

Novak, Laszlo; Emri, Miklos; Molnar, Peter; Balkay, Laszlo; Szabo, Sandor; Rozsa, Laszlo; Lengyel, Zsolt; Tron, Lajos

2006-12-01

The aim was to elucidate whether aneurysmal subarachnoid hemorrhage (SAH)-induced vasospasm induces changes of regional glucose uptake in surgically treated, asymptomatic cases. (18)FDG uptake (standardized uptake value, SUV) was analysed with PET in eight surgically treated aneurismal patients with a mean middle cerebral artery flow velocity >120 cm/seconds measured with transcranial Doppler ultrasound. Data were compared with a healthy control group using Statistical Parametric Mapping (SPM99b). Six of the eight patients had no focal neurological signs. The inhomogeneous bilateral increase in SUV (p<0.0001) was asymmetrical, with an almost 70% larger volume on the operated side. Reduced glucose uptake was found in the frontal and temporobasal regions of the two patients with neurological deficits (p<0.0001); the affected volume was 40% larger on the operated side. SAH-induced vasospasm results in widespread increase of glucose uptake-probably reflecting increased glycolysis. This was earlier than neurological focal signs appear. Decreased glucose uptake can be detected in severe cases of vasospasm reflected by neurological deficit. Although the changes are more prominent where surgery had taken place our results suggest that not only the surgery, but also subarachnoid blood might have resulted in our findings.

Alterations in regional shape on ipsilateral and contralateral cortex contrast in children with unilateral cerebral palsy and are predictive of multiple outcomes.

PubMed

Pagnozzi, Alex M; Dowson, Nicholas; Fiori, Simona; Doecke, James; Bradley, Andrew P; Boyd, Roslyn N; Rose, Stephen

2016-10-01

Congenital brain lesions result in a wide range of cerebral tissue alterations observed in children with cerebral palsy (CP) that are associated with a range of functional impairments. The relationship between injury severity and functional outcomes, however, remains poorly understood. This research investigates the differences in cortical shape between children with congenital brain lesions and typically developing children (TDC) and investigates the correlations between cortical shape and functional outcome in a large cohort of patients diagnosed with unilateral CP. Using 139 structural magnetic resonance images, including 95 patients with clinically diagnosed CP and 44 TDC, cortical segmentations were obtained using a modified expectation maximization algorithm. Three shape characteristics (cortical thickness, curvature, and sulcal depth) were computed within a number of cortical regions. Significant differences in these shape measures compared to the TDC were observed on both the injured hemisphere of children with CP (P < 0.004), as well as on the apparently uninjured hemisphere, illustrating potential compensatory mechanisms in these children. Furthermore, these shape measures were significantly correlated with several functional outcomes, including motor, cognition, vision, and communication (P < 0.012), with three out of these four models performing well on test set validation. This study highlights that cortical neuroplastic effects may be quantified using MR imaging, allowing morphological changes to be studied longitudinally, including any influence of treatment. Ultimately, such approaches could be used for the long term prediction of outcomes and the tailoring of treatment to individuals. Hum Brain Mapp 37:3588-3603, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Use of Electrical Impedance Tomography to Monitor Regional Cerebral Edema during Clinical Dehydration Treatment

PubMed Central

Hu, Shi-Jie; Li, Xia; Xu, Can-Hua; Wang, Bing; Yang, Bin; Tang, Meng-Xing; Dong, Xiu-Zhen; Fei, Zhou; Shi, Xue-Tao

2014-01-01

Objective Variations of conductive fluid content in brain tissue (e.g. cerebral edema) change tissue impedance and can potentially be measured by Electrical Impedance Tomography (EIT), an emerging medical imaging technique. The objective of this work is to establish the feasibility of using EIT as an imaging tool for monitoring brain fluid content. Design a prospective study. Setting In this study EIT was used, for the first time, to monitor variations in cerebral fluid content in a clinical model with patients undergoing clinical dehydration treatment. The EIT system was developed in house and its imaging sensitivity and spatial resolution were evaluated on a saline-filled tank. Patients 23 patients with brain edema. Interventions The patients were continuously imaged by EIT for two hours after initiation of dehydration treatment using 0.5 g/kg intravenous infusion of mannitol for 20 minutes. Measurement and Main Results Overall impedance across the brain increased significantly before and after mannitol dehydration treatment (p = 0.0027). Of the all 23 patients, 14 showed high-level impedance increase and maintained this around 4 hours after the dehydration treatment whereas the other 9 also showed great impedance gain during the treatment but it gradually decreased after the treatment. Further analysis of the regions of interest in the EIT images revealed that diseased regions, identified on corresponding CT images, showed significantly less impedance changes than normal regions during the monitoring period, indicating variations in different patients' responses to such treatment. Conclusions EIT shows potential promise as an imaging tool for real-time and non-invasive monitoring of brain edema patients. PMID:25474474

Quantifying interindividual variability and asymmetry of face-selective regions: a probabilistic functional atlas.

PubMed

Zhen, Zonglei; Yang, Zetian; Huang, Lijie; Kong, Xiang-Zhen; Wang, Xu; Dang, Xiaobin; Huang, Yangyue; Song, Yiying; Liu, Jia

2015-06-01

Face-selective regions (FSRs) are among the most widely studied functional regions in the human brain. However, individual variability of the FSRs has not been well quantified. Here we use functional magnetic resonance imaging (fMRI) to localize the FSRs and quantify their spatial and functional variabilities in 202 healthy adults. The occipital face area (OFA), posterior and anterior fusiform face areas (pFFA and aFFA), posterior continuation of the superior temporal sulcus (pcSTS), and posterior and anterior STS (pSTS and aSTS) were delineated for each individual with a semi-automated procedure. A probabilistic atlas was constructed to characterize their interindividual variability, revealing that the FSRs were highly variable in location and extent across subjects. The variability of FSRs was further quantified on both functional (i.e., face selectivity) and spatial (i.e., volume, location of peak activation, and anatomical location) features. Considerable interindividual variability and rightward asymmetry were found in all FSRs on these features. Taken together, our work presents the first effort to characterize comprehensively the variability of FSRs in a large sample of healthy subjects, and invites future work on the origin of the variability and its relation to individual differences in behavioral performance. Moreover, the probabilistic functional atlas will provide an adequate spatial reference for mapping the face network. Copyright © 2015 Elsevier Inc. All rights reserved.

Shortened dental arch and cerebral regional blood volume: an experimental pilot study with optical topography.

PubMed

Miyamoto, Ikuya; Yoshida, Kazuya; Bessho, Kazuhisa

2009-04-01

A shortened dental arch without posterior occlusal support has been thought to maintain sufficient oral function. The mechanism of occlusal adaptation with a shortened dental arch is unclear. For a better understanding of the effects of molar teeth on brain function, the authors combined experimentally-shortened dental arches and a neuro-imaging technique. Regional cerebral blood volume was measured using near-infrared optical topography during maximum voluntary clenching tasks from 10 subjects on individually fabricated oral appliances, which can create experimentally complete and shortened dental arches. Results suggested that clenching on the complete dental arch showed a significantly higher brain blood volume than that on the shortened dental arch. Moreover, there were no differences between the two splints in the latency to the maximum oxyhemoglobin concentration. These findings suggest that occlusal status is closely related to brain blood flow and lack of occlusal molar support rapidly reduces cerebral blood volume in the maximum voluntary clenching condition.

Regional cerebral perfusion for surgical correction of neonatal aortic arch obstruction.

PubMed

Zhang, Hui; Cheng, Pei; Hou, Jia; Li, Lei; Liu, Hu; Liu, Ruifang; Ji, Bingyang; Luo, Yi

2009-05-01

One-stage repair of aortic arch obstruction and associated cardiac anomalies is a surgical challenge in infants.The purpose of the present study is to review the current outcome using regional cerebral perfusion (RCP) during a procedure correcting interrupted aortic arch (IAA) and also isolated aortic coarctation (CoA) and CoA combined with hypoplastic aortic arch (CoA-HyAA) in our center. Between January 2007 and July 2008, 24 infant patients with interrupted aortic arch (IAA) (n=3), isolated aortic coarctation (iCoA) (n=9) and aortic coarctation with hypoplastic aortic arch (CoA-HyAA) (n=12) underwent one-stage surgical correction in our hospital. End-to-end anastomosis was employed in 12 infants (IAA n=3 and iCoA n=9); for the other 12 patients with CoA-HyAA, an end-to-end extended anastomosis was used in 8 cases, end-to-side anastomosis in 2 cases, and composite heterologous pericardial patch in 2 cases. RCP with 40 mL/kg/min through the innominate artery during aortic arch reconstruction was employed for all pediatric patients. One single-dose histidine-ketoglutarate-tryptophan (HTK) solution was used for myocardial protection during CPB. Cardiopulmonary bypass time and aortic cross-clamp time were 165.6+/-32.4 min and 81.7+/-30.0 min, respectively. The mean regional cerebral perfusion time was 31.0+/-10.6 min; lowest nasopharyngeal temperature was 19.1+/-1.1 degrees C. Operative mortality rate in both groups was 8.3%. Mean follow-up was 10.5+/-4.8 months. There was no late mortality or postoperative neurologic, renal or hepatic complications. All patients are asymptomatic and are developing normally. One-stage total arch repair using the RCP technique is an excellent method that may minimize neurologic and renal complications. Our surgical strategy for arch anomaly has a low rate of residual and recurrent coarctation when performed in these infants.

Impaired Cerebral Autoregulation Is Associated with Brain Atrophy and Worse Functional Status in Chronic Ischemic Stroke

PubMed Central

Aoi, Mikio C.; Hu, Kun; Lo, Men-Tzung; Selim, Magdy; Olufsen, Mette S.; Novak, Vera

2012-01-01

Dynamic cerebral autoregulation (dCA) is impaired following stroke. However, the relationship between dCA, brain atrophy, and functional outcomes following stroke remains unclear. In this study, we aimed to determine whether impairment of dCA is associated with atrophy in specific regions or globally, thereby affecting daily functions in stroke patients. We performed a retrospective analysis of 33 subjects with chronic infarctions in the middle cerebral artery territory, and 109 age-matched non-stroke subjects. dCA was assessed via the phase relationship between arterial blood pressure and cerebral blood flow velocity. Brain tissue volumes were quantified from MRI. Functional status was assessed by gait speed, instrumental activities of daily living (IADL), modified Rankin Scale, and NIH Stroke Score. Compared to the non-stroke group, stroke subjects showed degraded dCA bilaterally, and showed gray matter atrophy in the frontal, parietal and temporal lobes ipsilateral to infarct. In stroke subjects, better dCA was associated with less temporal lobe gray matter atrophy on the infracted side ( = 0.029), faster gait speed ( = 0.018) and lower IADL score (0.002). Our results indicate that better dynamic cerebral perfusion regulation is associated with less atrophy and better long-term functional status in older adults with chronic ischemic infarctions. PMID:23071639

Cerebral palsy characterization by estimating ocular motion

NASA Astrophysics Data System (ADS)

González, Jully; Atehortúa, Angélica; Moncayo, Ricardo; Romero, Eduardo

2017-11-01

Cerebral palsy (CP) is a large group of motion and posture disorders caused during the fetal or infant brain development. Sensorial impairment is commonly found in children with CP, i.e., between 40-75 percent presents some form of vision problems or disabilities. An automatic characterization of the cerebral palsy is herein presented by estimating the ocular motion during a gaze pursuing task. Specifically, After automatically detecting the eye location, an optical flow algorithm tracks the eye motion following a pre-established visual assignment. Subsequently, the optical flow trajectories are characterized in the velocity-acceleration phase plane. Differences are quantified in a small set of patients between four to ten years.

Planning-free cerebral blood flow territory mapping in patients with intracranial arterial stenosis

PubMed Central

Arteaga, Daniel F; Strother, Megan K; Davis, L Taylor; Fusco, Matthew R; Faraco, Carlos C; Roach, Brent A; Scott, Allison O

2016-01-01

A noninvasive method for quantifying cerebral blood flow and simultaneously visualizing cerebral blood flow territories is vessel-encoded pseudocontinuous arterial spin labeling MRI. However, obstacles to acquiring such information include limited access to the methodology in clinical centers and limited work on how clinically acquired vessel-encoded pseudocontinuous arterial spin labeling data correlate with gold-standard methods. The purpose of this work is to develop and validate a semiautomated pipeline for the online quantification of cerebral blood flow maps and cerebral blood flow territories from planning-free vessel-encoded pseudocontinuous arterial spin labeling MRI with gold-standard digital subtraction angiography. Healthy controls (n = 10) and intracranial atherosclerotic disease patients (n = 34) underwent 3.0 T MRI imaging including vascular (MR angiography) and hemodynamic (cerebral blood flow-weighted arterial spin labeling) MRI. Patients additionally underwent catheter and/or CT angiography. Variations in cross-territorial filling were grouped according to diameters of circle of Willis vessels in controls. In patients, Cohen’s k-statistics were computed to quantify agreement in perfusion patterns between vessel-encoded pseudocontinuous arterial spin labeling and angiography. Cross-territorial filling patterns were consistent with circle of Willis anatomy. The intraobserver Cohen's k-statistics for cerebral blood flow territory and digital subtraction angiography perfusion agreement were 0.730 (95% CI = 0.593–0.867; reader one) and 0.708 (95% CI = 0.561–0.855; reader two). These results support the feasibility of a semiautomated pipeline for evaluating major neurovascular cerebral blood flow territories in patients with intracranial atherosclerotic disease. PMID:27389177

Effects of rapamycin on cerebral oxygen supply and consumption during reperfusion after cerebral ischemia.

PubMed

Chi, O Z; Barsoum, S; Vega-Cotto, N M; Jacinto, E; Liu, X; Mellender, S J; Weiss, H R

2016-03-01

Activation of the mammalian target of rapamycin (mTOR) leads to cell growth and survival. We tested the hypothesis that inhibition of mTOR would increase infarct size and decrease microregional O2 supply/consumption balance after cerebral ischemia-reperfusion. This was tested in isoflurane-anesthetized rats with middle cerebral artery blockade for 1h and reperfusion for 2h with and without rapamycin (20mg/kg once daily for two days prior to ischemia). Regional cerebral blood flow was determined using a C(14)-iodoantipyrine autoradiographic technique. Regional small-vessel arterial and venous oxygen saturations were determined microspectrophotometrically. The control ischemic-reperfused cortex had a similar blood flow and O2 consumption to the contralateral cortex. However, microregional O2 supply/consumption balance was significantly reduced in the ischemic-reperfused cortex. Rapamycin significantly increased cerebral O2 consumption and further reduced O2 supply/consumption balance in the reperfused area. This was associated with an increased cortical infarct size (13.5±0.8% control vs. 21.5±0.9% rapamycin). We also found that ischemia-reperfusion increased AKT and S6K1 phosphorylation, while rapamycin decreased this phosphorylation in both the control and ischemic-reperfused cortex. This suggests that mTOR is important for not only cell survival, but also for the control of oxygen balance after cerebral ischemia-reperfusion. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

Autistic Traits, ADHD Symptoms, Neurological Soft Signs and Regional Cerebral Blood Flow in Adults with Autism Spectrum Disorders

ERIC Educational Resources Information Center

Manouilenko, Irina; Pagani, Marco; Stone-Elander, Sharon; Odh, Richard; Brolin, Fredrik; Hatherly, Robert; Jacobsson, Hans; Larsson, Stig A.; Bejerot, Susanne

2013-01-01

The resting regional cerebral blood flow (rCBF) patterns related to co-occurring symptoms such as inattention, hyperactivity, neurological soft signs and motor problems have not yet been disclosed in autism spectrum disorders (ASD). In this study thirteen adults with ASD and ten matched neurotypical controls underwent PET. The scores of rating…

[The cerebral hemodynamics in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy].

PubMed

Jin, De-xin; Chen, Xiu-yun; Huang, He; Zhang, Xu

2006-12-01

To investigate the cerebral hemodynamics in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). The blood flow velocity of cerebral arteries was measured by using transcranial Doppler ultrasound (TCD) in 6 cases with CADASIL and a quite number of age and sex matched control subjects. All patients (4 were symptomatic and 2 asymptomatic), being an established CADASIL family with the diagnosis confirmed by clinical characteristics, neuroimaging, pathology and molecular genetics, had abnormal mark signals on MR imagining and no history of hypertension, diabetes, heart disease and migraine. A routinely TCD detection, including peak-systolic velocity (Vp), end-diastolic velocity (Vd), mean velocity (Vm) and pulsatility index (PI), was carried out on the bilateral middle cerebral arteries (MCA), anterior cerebral arteries (ACA), posterior cerebral arteries (PCA) and vertebral arteries (VA) as well as the basilar artery (BA). A comparison between the cases and controls was made. Then, the changes of flow velocity in middle cerebral arteries (MCA) of the patients with CADASIL were observed before and after breathholding tests. In addition, brain CT perfusion imaging (CTP) was carried out in all the cases by using 16-slice spiral CT. The appearances of frequency spectrum were nearly normal in all the cases and there was no abnormality between the two sides on velocity (P > 0.05). As compared with the controls, the bilateral Vp, Vd and Vm in ACA and PCA were decreased obviously (P < 0.05). The velocity parameters of MCA with the exception of left Vm and right PI showed changes (P < 0.05) and there were no changes of PI in the bilateral ACA, PCA and Left MCA (P > 0.05). Moreover, there were marked changes in MCA (including Vm, Vd and PI) of all the cases as compared with the controls after breathholding (P < 0.01). Brain perfusion imaging showing the regional cerebral blood flow and regional cerebral blood volume in frontal

Cerebellar asymmetry and its relation to cerebral asymmetry estimated by intrinsic functional connectivity

PubMed Central

Wang, Danhong; Buckner, Randy L.

2013-01-01

Asymmetry of the human cerebellum was investigated using intrinsic functional connectivity. Regions of functional asymmetry within the cerebellum were identified during resting-state functional MRI (n = 500 subjects) and replicated in an independent cohort (n = 500 subjects). The most strongly right lateralized cerebellar regions fell within the posterior lobe, including crus I and crus II, in regions estimated to link to the cerebral association cortex. The most strongly left lateralized cerebellar regions were located in lobules VI and VIII in regions linked to distinct cerebral association networks. Comparison of cerebellar asymmetry with independently estimated cerebral asymmetry revealed that the lateralized regions of the cerebellum belong to the same networks that are strongly lateralized in the cerebrum. The degree of functional asymmetry of the cerebellum across individuals was significantly correlated with cerebral asymmetry and varied with handedness. In addition, cerebellar asymmetry estimated at rest predicted cerebral lateralization during an active language task. These results demonstrate that functional lateralization is likely a unitary feature of large-scale cerebrocerebellar networks, consistent with the hypothesis that the cerebellum possesses a roughly homotopic map of the cerebral cortex including the prominent asymmetries of the association cortex. PMID:23076113

Shy-Drager syndrome. Effect of fludrocortisone and L-threo-3,4-dihydroxyphenylserine on the blood pressure and regional cerebral blood flow.

PubMed Central

Matsubara, S; Sawa, Y; Yokoji, H; Takamori, M

1990-01-01

In nine cases of Shy-Drager syndrome, the changes in blood pressure and cerebral blood flow on sitting up from a supine position were studied. The influence of fludrocortisone, a synthetic mineralocorticoid, and L-threo-3,4-dihydroxyphenylserine (DOPS), a precursor of norepinephrine, on these changes was examined. On sitting up, the regional cerebral blood flow (rCBF) measured by Xe133 inhalation showed a tendency to decrease. Fludrocortisone reduced the fall of the mean blood pressure significantly. DOPS reduced the fall of both the diastolic blood pressure and rCBF significantly. PMID:2283531

Different Alterations of Cerebral Regional Homogeneity in Early-Onset and Late-Onset Parkinson's Disease

PubMed Central

Sheng, Ke; Fang, Weidong; Zhu, Yingcheng; Shuai, Guangying; Zou, Dezhi; Su, Meilan; Han, Yu; Cheng, Oumei

2016-01-01

HIGHLIGHTS Eighteen EOPD, 21 LOPD and 37 age-matched normal control subjects participated in the resting state fMRI scans.Age at onset of PD modulates the distribution of cerebral regional homogeneity during resting state.Disproportionate putamen alterations are more prominent in PD patients with a younger age of onset. Objective: Early-onset Parkinson's disease (EOPD) is distinct from late-onset PD (LOPD) as it relates to the clinical profile and response to medication. The objective of current paper is to investigate whether characteristics of spontaneous brain activity in the resting state are associated with the age of disease onset. Methods: We assessed the correlation between neural activity and age-at-onset in a sample of 39 PD patients (18 EOPD and 21 LOPD) and 37 age-matched normal control subjects. Regional homogeneity (ReHo) approaches were employed using ANOVA with two factors: PD and age. Results: In the comparisons between LOPD and EOPD, EOPD revealed lower ReHo values in the right putamen and higher ReHo values in the left superior frontal gyrus. Compared with age-matched control subjects, EOPD exhibited lower ReHo values in the right putamen and higher ReHo values in the left inferior temporal gyrus; However, LOPD showed lower ReHo values in the right putamen and left insula. The ReHo values were negatively correlated with the UPDRS total scores in the right putamen in LOPD, but a correlation between the ReHo value and UPDRS score was not detected in EOPD. Conclusions: Our findings support the notion that age at onset is associated with the distribution of cerebral regional homogeneity in the resting state and suggest that disproportionate putamen alterations are more prominent in patients with a younger age of onset. PMID:27462265

Effects of ischemic stroke on dynamics of cerebral autoregulation

NASA Astrophysics Data System (ADS)

Chen, Zhi; Ivanov, Plamen Ch; Hu, Kun; Stanley, Eugene; Novak, Vera

2004-03-01

Cerebral vasoregulation involves several complex mechanisms adapting blood flow to fluctuations of systemic blood pressure (BP). Autonomic BP and metabolic vasoregulation are impaired after stroke and cerebral blood flow depends on systemic BP. To probe the mechanisms of cerebral autoregulation we study levels of nonlinear synchronization between cerebral blood flow velocity (BFV) and peripheral BP. We quantify the instantaneous phase of each signal employing analytic signal approach and Hilbert transform. As a marker of synchronization, we introduce a measure of cross-correlation between the instantaneous phase increments of the BFV and BP signals at different time lags. We have studied 12 subjects with minor chronic ischemic stroke and 11 matched normotensive controls (age<65years). BFV and BP of these subjects are continuously recorded during supine baseline, head-up tilt, hyperventilation and CO2 rebreathing. For control subjects we find significant synchronization between cerebral BFV and peripheral BP only for short time lags of up to 5-6 seconds, suggesting a rapid return to a steady cerebral blood flow after initial blood pressure perturbations. In contrast, for stroke subjects BFV/BP we find enhanced synchronization over longer time lags of up to 20 seconds, suggesting entrainment of cerebral blood flow velocity by slow vasomotor rhythms. These findings suggest that cerebral vasoregulation is impaired and cerebral blood flow follows the fluctuations of systemic BP in a synchronous manner. Our analysis shows that cerebral autoregulation is impaired in 10 out of the 12 stroke subjects, which is typically difficult to diagnose with conventional methods. Thus, our novel synchronization approach offers a new tool sensitive for evaluation of changes in the dynamics of cerebral autoregulation under stroke.

The Cerebellar-Cerebral Microstructure Is Disrupted at Multiple Sites in Very Preterm Infants with Cerebellar Haemorrhage.

PubMed

Neubauer, Vera; Djurdjevic, Tanja; Griesmaier, Elke; Biermayr, Marlene; Gizewski, Elke Ruth; Kiechl-Kohlendorfer, Ursula

2018-01-01

Recent advances in magnetic resonance imaging (MRI) techniques have prompted reconsideration of the anatomical correlates of adverse outcomes in preterm infants. The importance of the contribution made by the cerebellum is now increasingly appreciated. The effect of cerebellar haemorrhage (CBH) on the microstructure of the cerebellar-cerebral circuit is largely unexplored. To investigate the effect of CBH on the microstructure of cerebellar-cerebral connections in preterm infants aged <32 gestational weeks. Infants underwent diffusion tensor MRI at term-equivalent age. MRI was evaluated for CBH and additional supratentorial brain injury using a validated scoring system. Region of interest-based measures of brain microstructure (fractional anisotropy [FA] and apparent diffusion coefficient) were quantified in 5 vulnerable regions (the centrum semiovale, posterior limb of the internal capsule, corpus callosum, and superior and middle cerebellar peduncles). Group differences between infants with CBH and infants without CBH were assessed. There were 267 infants included in the study. Infants with CBH (isolated and combined) had significantly lower FA values in all regions investigated. Infants with isolated CBH showed lower FA in the middle and superior cerebellar peduncles and in the posterior limb of the internal capsule. This study provides evidence that CBH causes alterations in localised and remote WM pathways in the developing brain. The disruption of the cerebellar-cerebral microstructure at multiple sites adds further support for the concept of developmental diaschisis, which is propagated as an explanation for the consequences of early cerebellar injury on cognitive and affective domains. © 2017 S. Karger AG, Basel.

Proteomic identification of altered cerebral proteins in the complex regional pain syndrome animal model.

PubMed

Nahm, Francis Sahngun; Park, Zee-Yong; Nahm, Sang-Soep; Kim, Yong Chul; Lee, Pyung Bok

2014-01-01

Complex regional pain syndrome (CRPS) is a rare but debilitating pain disorder. Although the exact pathophysiology of CRPS is not fully understood, central and peripheral mechanisms might be involved in the development of this disorder. To reveal the central mechanism of CRPS, we conducted a proteomic analysis of rat cerebrum using the chronic postischemia pain (CPIP) model, a novel experimental model of CRPS. After generating the CPIP animal model, we performed a proteomic analysis of the rat cerebrum using a multidimensional protein identification technology, and screened the proteins differentially expressed between the CPIP and control groups. Results. A total of 155 proteins were differentially expressed between the CPIP and control groups: 125 increased and 30 decreased; expressions of proteins related to cell signaling, synaptic plasticity, regulation of cell proliferation, and cytoskeletal formation were increased in the CPIP group. However, proenkephalin A, cereblon, and neuroserpin were decreased in CPIP group. Altered expression of cerebral proteins in the CPIP model indicates cerebral involvement in the pathogenesis of CRPS. Further study is required to elucidate the roles of these proteins in the development and maintenance of CRPS.

Estimation of regional cerebral blood flow distribution in infants by multichannel near-infrared spectroscopy with indocyanine green

NASA Astrophysics Data System (ADS)

Kusaka, Takashi; Isobe, Kenichi; Nagano, Keiko; Okubo, Kensuke; Yasuda, Saneyuki; Kawada, Kou; Itoh, Susumu; Onishi, Shoju; Oda, Ichiro; Wada, Yukihisa; Konishi, Ikuo; Tsunazawa, Yoshio

2001-06-01

This is the report on the use of multichannel near-infrared spectroscopy (MNIRS) with indocyanine green (ICG) to determine regional cerebral blood flow (rCBF) distribution disturbance in infants. We measured rCBF in an infant with subdural hemorrhage after surgical removal of a subdural hematoma. A probe consisting of 12 optical fibers, 6 for transmission and 6 for detection, was set on the right and then left temporal regions of the head of the infant, and 16 measuring points were determined. Changes in ICG concentration were recorded using MNIRS (near infrared optical imaging system, OMM-2000, Shimadzu Corp., Japan).

[Indicators of general, cerebral, and regional hemodynamics in myopic schoolchildren aged 13-15 years].

PubMed

Iastrebtseva, T A; Chuprov, A D; Plotnikova, Iu A

2002-01-01

110 schoolchildren aged 13-15 years were examined. 24 of them had pseudomyopia and 6 patients myopia of various forms. A control group consisted of 38 children. Central hemodynamics was estimated by average dynamic pressure, cerebral hemodynamics--by rheoencephalography, regional hemodynamics--by dopplerography of the internal carotid and suprapubic arteries. It was found that with myopia progression, the average dynamic pressure positively comes down with reduction of reographic waves amplitude in rheogram. The blood flow rate in internal carotid and suprapubic arteries has no substantial impact on myopia course. Predisposition to arterial hypotension is a risk factor for myopia development and progression.

Regional Cerebral Oximetry During Cardiopulmonary Resuscitation: Useful or Useless?

PubMed

Genbrugge, Cornelia; Dens, Jo; Meex, Ingrid; Boer, Willem; Eertmans, Ward; Sabbe, Marc; Jans, Frank; De Deyne, Cathy

2016-01-01

Approximately 375,000 people annually experience sudden cardiac arrest (CA) in Europe. Most patients who survive the initial hours and days after CA die of postanoxic brain damage. Current monitors, such as electrocardiography and end-tidal capnography, provide only indirect information about the condition of the brain during cardiopulmonary resuscitation (CPR). In contrast, cerebral near-infrared spectroscopy provides continuous, noninvasive, real-time information about brain oxygenation without the need for a pulsatile blood flow. It measures transcutaneous cerebral tissue oxygen saturation (rSO2). This information could supplement currently used monitors. Moreover, an evolution in rSO2 monitoring technology has made it easier to assess rSO2 in CA conditions. We give an overview of the literature regarding rSO2 measurements during CPR and the current commercially available devices. We highlight the feasibility of cerebral saturation measurement during CPR, its role as a quality parameter of CPR, predictor of return of spontaneous circulation (ROSC) and neurologic outcome, and its monitoring function during transport. rSO2 is feasible in the setting of CA and has the potential to measure the quality of CPR, predict ROSC and neurologic outcome, and monitor post-CA patients during transport. The literature shows that rSO2 has the potential to serve multiple roles as a neuromonitoring tool during CPR and also to guide neuroprotective therapeutic strategies. Copyright © 2016 Elsevier Inc. All rights reserved.

Quantifying landscape linkages among giant panda subpopulations in regional scale conservation.

PubMed

Qi, Dunwu; Hu, Yibo; Gu, Xiaodong; Yang, Xuyi; Yang, Guang; Wei, Fuwen

2012-06-01

Understanding habitat requirements and identifying landscape linkages are essential for the survival of isolated populations of endangered species. Currently, some of the giant panda populations are isolated, which threatens their long-term survival, particularly in the Xiaoxiangling mountains. In the present study, we quantified niche requirements and then identified potential linkages of giant panda subpopulations in the most isolated region, using ecological niche factor analysis and a least-cost path model. Giant pandas preferred habitat with conifer forest and gentle slopes (>20 to ≤30°). Based on spatial distribution of suitable habitat, linkages were identified for the Yele subpopulation to 4 other subpopulations (Liziping, Matou, Xinmin and Wanba). Their lengths ranged from 15 to 54 km. The accumulated cost ranged from 693 to 3166 and conifer forest covered over 31%. However, a variety of features (e.g. major roads, human settlements and large unforested areas) might act as barriers along the linkages for giant panda dispersal. Our analysis quantified giant panda subpopulation connectivity to ensure long-term survival. © 2012 ISZS, Blackwell Publishing and IOZ/CAS.

Plantar flexor muscle weakness and fatigue in spastic cerebral palsy patients.

PubMed

Neyroud, Daria; Armand, Stéphane; De Coulon, Geraldo; Sarah R Dias Da Silva; Maffiuletti, Nicola A; Kayser, Bengt; Place, Nicolas

2017-02-01

Patients with cerebral palsy develop an important muscle weakness which might affect the aetiology and extent of exercise-induced neuromuscular fatigue. This study evaluated the aetiology and extent of plantar flexor neuromuscular fatigue in patients with cerebral palsy. Ten patients with cerebral palsy and 10 age- and sex-matched healthy individuals (∼20 years old, 6 females) performed four 30-s maximal isometric plantar flexions interspaced by a resting period of 2-3s to elicit a resting twitch. Maximal voluntary contraction force, voluntary activation level and peak twitch were quantified before and immediately after the fatiguing task. Before fatigue, patients with cerebral palsy were weaker than healthy individuals (341±134N vs. 858±151N, p<0.05) and presented lower voluntary activation (73±19% vs. 90±9%, p<0.05) and peak twitch (100±28N vs. 199±33N, p<0.05). Maximal voluntary contraction force was not significantly reduced in patients with cerebral palsy following the fatiguing task (-10±23%, p>0.05), whereas it decreased by 30±12% (p<0.05) in healthy individuals. Plantar flexor muscles of patients with cerebral palsy were weaker than their healthy peers but showed greater fatigue resistance. Cerebral palsy is a widely defined pathology that is known to result in muscle weakness. The extent and origin of muscle weakness were the topic of several previous investigations; however some discrepant results were reported in the literature regarding how it might affect the development of exercise-induced neuromuscular fatigue. Importantly, most of the studies interested in the assessment of fatigue in patients with cerebral palsy did so with general questionnaires and reported increased levels of fatigue. Yet, exercise-induced neuromuscular fatigue was quantified in just a few studies and it was found that young patients with cerebral palsy might be more fatigue resistant that their peers. Thus, it appears that (i) conflicting results exist regarding

Applying time-frequency analysis to assess cerebral autoregulation during hypercapnia.

PubMed

Placek, Michał M; Wachel, Paweł; Iskander, D Robert; Smielewski, Peter; Uryga, Agnieszka; Mielczarek, Arkadiusz; Szczepański, Tomasz A; Kasprowicz, Magdalena

2017-01-01

Classic methods for assessing cerebral autoregulation involve a transfer function analysis performed using the Fourier transform to quantify relationship between fluctuations in arterial blood pressure (ABP) and cerebral blood flow velocity (CBFV). This approach usually assumes the signals and the system to be stationary. Such an presumption is restrictive and may lead to unreliable results. The aim of this study is to present an alternative method that accounts for intrinsic non-stationarity of cerebral autoregulation and the signals used for its assessment. Continuous recording of CBFV, ABP, ECG, and end-tidal CO2 were performed in 50 young volunteers during normocapnia and hypercapnia. Hypercapnia served as a surrogate of the cerebral autoregulation impairment. Fluctuations in ABP, CBFV, and phase shift between them were tested for stationarity using sphericity based test. The Zhao-Atlas-Marks distribution was utilized to estimate the time-frequency coherence (TFCoh) and phase shift (TFPS) between ABP and CBFV in three frequency ranges: 0.02-0.07 Hz (VLF), 0.07-0.20 Hz (LF), and 0.20-0.35 Hz (HF). TFPS was estimated in regions locally validated by statistically justified value of TFCoh. The comparison of TFPS with spectral phase shift determined using transfer function approach was performed. The hypothesis of stationarity for ABP and CBFV fluctuations and the phase shift was rejected. Reduced TFPS was associated with hypercapnia in the VLF and the LF but not in the HF. Spectral phase shift was also decreased during hypercapnia in the VLF and the LF but increased in the HF. Time-frequency method led to lower dispersion of phase estimates than the spectral method, mainly during normocapnia in the VLF and the LF. The time-frequency method performed no worse than the classic one and yet may offer benefits from lower dispersion of phase shift as well as a more in-depth insight into the dynamic nature of cerebral autoregulation.

Regional Cerebral Blood Flow during Wakeful Rest in Older Subjects with Mild to Severe Obstructive Sleep Apnea

PubMed Central

Baril, Andrée-Ann; Gagnon, Katia; Arbour, Caroline; Soucy, Jean-Paul; Montplaisir, Jacques; Gagnon, Jean-François; Gosselin, Nadia

2015-01-01

Objectives: To evaluate changes in regional cerebral blood flow (rCBF) during wakeful rest in older subjects with mild to severe obstructive sleep apnea (OSA) and healthy controls, and to identify markers of OSA severity that predict altered rCBF. Design: High-resolution 99mTc-HMPAO SPECT imaging during wakeful rest. Setting: Research sleep laboratory affiliated with a University hospital. Participants: Fifty untreated OSA patients aged between 55 and 85 years, divided into mild, moderate, and severe OSA, and 20 age-matched healthy controls. Interventions: N/A. Measurements: Using statistical parametric mapping, rCBF was compared between groups and correlated with clinical, respiratory, and sleep variables. Results: Whereas no rCBF change was observed in mild and moderate groups, participants with severe OSA had reduced rCBF compared to controls in the left parietal lobules, left precentral gyrus, bilateral postcentral gyri, and right precuneus. Reduced rCBF in these regions and in areas of the bilateral frontal and left temporal cortex was associated with more hypopneas, snoring, hypoxemia, and sleepiness. Higher apnea, microarousal, and body mass indexes were correlated to increased rCBF in the basal ganglia, insula, and limbic system. Conclusions: While older individuals with severe obstructive sleep apnea (OSA) had hypoperfusion in the sensorimotor and parietal areas, respiratory variables and subjective sleepiness were correlated with extended regions of hypoperfusion in the lateral cortex. Interestingly, OSA severity, sleep fragmentation, and obesity correlated with increased perfusion in subcortical and medial cortical regions. Anomalies with such a distribution could result in cognitive deficits and reflect impaired vascular regulation, altered neuronal integrity, and/or undergoing neurodegenerative processes. Citation: Baril AA, Gagnon K, Arbour C, Soucy JP, Montplaisir J, Gagnon JF, Gosselin N. Regional cerebral blood flow during wakeful rest in older

Smart catheter flow sensor for real-time continuous regional cerebral blood flow monitoring

NASA Astrophysics Data System (ADS)

Li, Chunyan; Wu, Pei-Ming; Hartings, Jed A.; Wu, Zhizhen; Ahn, Chong H.; LeDoux, David; Shutter, Lori A.; Narayan, Raj K.

2011-12-01

We present a smart catheter flow sensor for real-time, continuous, and quantitative measurement of regional cerebral blood flow using in situ temperature and thermal conductivity compensation. The flow sensor operates in a constant-temperature mode and employs a periodic heating and cooling technique. This approach ensures zero drift and provides highly reliable data with microelectromechanical system-based thin film sensors. The developed flow sensor has a sensitivity of 0.973 mV/ml/100 g/min in the range from 0 to 160 ml/100 g/min with a linear correlation coefficient of R2 = 0.9953. It achieves a resolution of 0.25 ml/100 g/min and an accuracy better than 5 ml/100 g/min.

Regional brain blood flow and cerebral hemispheric oxygen consumption during acute hypoxaemia in the llama fetus

PubMed Central

Llanos, Aníbal J; Riquelme, Raquel A; Sanhueza, Emilia M; Herrera, Emilio; Cabello, Gertrudis; Giussani, Dino A; Parer, Julian T

2002-01-01

Unlike fetal animals of lowland species, the llama fetus does not increase its cerebral blood flow during an episode of acute hypoxaemia. This study tested the hypothesis that the fetal llama brain maintains cerebral hemispheric O2 consumption by increasing cerebral O2 extraction rather than decreasing cerebral oxygen utilisation during acute hypoxaemia. Six llama fetuses were surgically instrumented under general anaesthesia at 217 days of gestation (term ca 350 days) with vascular and amniotic catheters in order to carry out cardiorespiratory studies. Following a control period of 1 h, the llama fetuses underwent 3 × 20 min episodes of progressive hypoxaemia, induced by maternal inhalational hypoxia. During basal conditions and during each of the 20 min of hypoxaemia, fetal cerebral blood flow was measured with radioactive microspheres, cerebral oxygen extraction was calculated, and fetal cerebral hemispheric O2 consumption was determined by the modified Fick principle. During hypoxaemia, fetal arterial O2 tension and fetal pH decreased progressively from 24 ± 1 to 20 ± 1 Torr and from 7.36 ± 0.01 to 7.33 ± 0.01, respectively, during the first 20 min episode, to 16 ± 1 Torr and 7.25 ± 0.05 during the second 20 min episode and to 14 ± 1 Torr and 7.21 ± 0.04 during the final 20 min episode. Fetal arterial partial pressure of CO2 (Pa,CO2, 42 ± 2 Torr) remained unaltered from baseline throughout the experiment. Fetal cerebral hemispheric blood flow and cerebral hemispheric oxygen extraction were unaltered from baseline during progressive hypoxaemia. In contrast, a progressive fall in fetal cerebral hemispheric oxygen consumption occurred during the hypoxaemic challenge. In conclusion, these data do not support the hypothesis that the fetal llama brain maintains cerebral hemispheric O2 consumption by increasing cerebral hemispheric O2 extraction. Rather, the data show that in the llama fetus, a reduction in cerebral hemispheric metabolism occurs during acute

Mood disturbances and regional cerebral metabolic abnormalities in recently abstinent methamphetamine abusers.

PubMed

London, Edythe D; Simon, Sara L; Berman, Steven M; Mandelkern, Mark A; Lichtman, Aaron M; Bramen, Jennifer; Shinn, Ann K; Miotto, Karen; Learn, Jennifer; Dong, Yun; Matochik, John A; Kurian, Varughese; Newton, Thomas; Woods, Roger; Rawson, Richard; Ling, Walter

2004-01-01

Mood disturbances in methamphetamine (MA) abusers likely influence drug use, but the neurobiological bases for these problems are poorly understood. To assess regional brain function and its possible relationships with negative affect in newly abstinent MA abusers. Two groups were compared by measures of mood and cerebral glucose metabolism ([18F]fluorodeoxyglucose positron emission tomography) during performance of a vigilance task. Participants were recruited from the general community to a research center. Seventeen abstaining (4-7 days) MA abusers (6 women) were compared with 18 control subjects (8 women). Self-reports of depressive symptoms and anxiety were measured, as were global and relative glucose metabolism in the orbitofrontal, cingulate, lateral prefrontal, and insular cortices and the amygdala, striatum, and cerebellum. Abusers of MA provided higher self-ratings of depression and anxiety than control subjects and differed significantly in relative regional glucose metabolism: lower in the anterior cingulate and insula and higher in the lateral orbitofrontal area, middle and posterior cingulate, amygdala, ventral striatum, and cerebellum. In MA abusers, self-reports of depressive symptoms covaried positively with relative glucose metabolism in limbic regions (eg, perigenual anterior cingulate gyrus and amygdala) and ratings of state and trait anxiety covaried negatively with relative activity in the anterior cingulate cortex and left insula. Trait anxiety also covaried negatively with relative activity in the orbitofrontal cortex and positively with amygdala activity. Abusers of MA have abnormalities in brain regions implicated in mood disorders. Relationships between relative glucose metabolism in limbic and paralimbic regions and self-reports of depression and anxiety in MA abusers suggest that these regions are involved in affective dysregulation and may be an important target of intervention for MA dependence.

[Effects of carbon dioxide insufflation on regional cerebral oxygenation during laparoscopic surgery in children: a prospective study].

PubMed

Tuna, Ayca Tas; Akkoyun, Ibrahim; Darcin, Sevtap; Palabiyik, Onur

2016-01-01

Laparoscopic surgery has become a popular surgical tool when compared to traditional open surgery. There are limited data on pediatric patients regarding whether pneumoperitoneum affects cerebral oxygenation although end-tidal CO2 concentration remains normal. Therefore, this study was designed to evaluate the changes of cerebral oxygen saturation using near-infrared spectroscope during laparoscopic surgery in children. The study comprised forty children who were scheduled for laparoscopic (Group L, n=20) or open (Group O, n=20) appendectomy. Hemodynamic variables, right and left regional cerebral oxygen saturation (RrSO2 and LrSO2), fraction of inspired oxygen, end-tidal carbon dioxide pressure (PETCO2), peak inspiratory pressure (Ppeak), respiratory minute volume, inspiratory and end-tidal concentrations of sevoflurane and body temperature were recorded. All parameters were recorded after anesthesia induction and before start of surgery (T0, baseline), 15min after start of surgery (T1), 30min after start of surgery (T2), 45min after start of surgery (T3), 60min after start of surgery (T4) and end of the surgery (T5). There were progressive decreases in both RrSO2 and LrSO2 levels in both groups, which were not statistically significant at T1, T2, T3, T4. The RrSO2 levels of Group L at T5 were significantly lower than that of Group O. One patient in Group L had an rSO2 value <80% of the baseline value. Carbon dioxide insufflation during pneumoperitoneum in pediatric patients may not affect cerebral oxygenation under laparoscopic surgery. Copyright © 2015 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.

Effects of carbon dioxide insufflation on regional cerebral oxygenation during laparoscopic surgery in children: a prospective study.

PubMed

Tuna, Ayca Tas; Akkoyun, Ibrahim; Darcin, Sevtap; Palabiyik, Onur

2016-01-01

Laparoscopic surgery has become a popular surgical tool when compared to traditional open surgery. There are limited data on pediatric patients regarding whether pneumoperitoneum affects cerebral oxygenation although end-tidal CO2 concentration remains normal. Therefore, this study was designed to evaluate the changes of cerebral oxygen saturation using near-infrared spectroscope during laparoscopic surgery in children. The study comprised forty children who were scheduled for laparoscopic (Group L, n=20) or open (Group O, n=20) appendectomy. Hemodynamic variables, right and left regional cerebral oxygen saturation (RrSO2 and LrSO2), fraction of inspired oxygen, end-tidal carbon dioxide pressure (PETCO2), peak inspiratory pressure (Ppeak), respiratory minute volume, inspiratory and end-tidal concentrations of sevoflurane and body temperature were recorded. All parameters were recorded after anesthesia induction and before start of surgery (T0, baseline), 15min after start of surgery (T1), 30min after start of surgery (T2), 45min after start of surgery (T3), 60min after start of surgery (T4) and end of the surgery (T5). There were progressive decreases in both RrSO2 and LrSO2 levels in both groups, which were not statistically significant at T1, T2, T3, T4. The RrSO2 levels of Group L at T5 were significantly lower than that of Group O. One patient in Group L had an rSO2 value <80% of the baseline value. Carbon dioxide insufflation during pneumoperitoneum in pediatric patients may not affect cerebral oxygenation under laparoscopic surgery. Copyright © 2015 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rights reserved.

Relationship between regional cerebral metabolism and consciousness disturbance in traumatic diffuse brain injury without large focal lesions: an FDG-PET study with statistical parametric mapping analysis.

PubMed

Nakayama, N; Okumura, A; Shinoda, J; Nakashima, T; Iwama, T

2006-07-01

The cerebral metabolism of patients in the chronic stage of traumatic diffuse brain injury (TDBI) has not been fully investigated. To study the relationship between regional cerebral metabolism (rCM) and consciousness disturbance in patients with TDBI. 52 patients with TDBI in the chronic stage without large focal lesions were enrolled, and rCM was evaluated by fluorine-18-fluorodeoxyglucose positron emission tomography (FDG-PET) with statistical parametric mapping (SPM). All the patients were found to have disturbed consciousness or cognitive function and were divided into the following three groups: group A (n = 22), patients in a state with higher brain dysfunction; group B (n = 13), patients in a minimally conscious state; and group C (n = 17), patients in a vegetative state. rCM patterns on FDG-PET among these groups were evaluated and compared with those of normal control subjects on statistical parametric maps. Hypometabolism was consistently indicated bilaterally in the medial prefrontal regions, the medial frontobasal regions, the cingulate gyrus and the thalamus. Hypometabolism in these regions was the most widespread and prominent in group C, and that in group B was more widespread and prominent than that in group A. Bilateral hypometabolism in the medial prefrontal regions, the medial frontobasal regions, the cingulate gyrus and the thalamus may reflect the clinical deterioration of TDBI, which is due to functional and structural disconnections of neural networks rather than due to direct cerebral focal contusion.

Regional differences in the morphological and functional effects of aging on cerebral basement membranes and perivascular drainage of amyloid-β from the mouse brain.

PubMed

Hawkes, Cheryl A; Gatherer, Maureen; Sharp, Matthew M; Dorr, Adrienne; Yuen, Ho Ming; Kalaria, Rajesh; Weller, Roy O; Carare, Roxana O

2013-04-01

Development of cerebral amyloid angiopathy (CAA) and Alzheimer's disease (AD) is associated with failure of elimination of amyloid-β (Aβ) from the brain along perivascular basement membranes that form the pathways for drainage of interstitial fluid and solutes from the brain. In transgenic APP mouse models of AD, the severity of cerebral amyloid angiopathy is greater in the cerebral cortex and hippocampus, intermediate in the thalamus, and least in the striatum. In this study we test the hypothesis that age-related regional variation in (1) vascular basement membranes and (2) perivascular drainage of Aβ contribute to the different regional patterns of CAA in the mouse brain. Quantitative electron microscopy of the brains of 2-, 7-, and 23-month-old mice revealed significant age-related thickening of capillary basement membranes in cerebral cortex, hippocampus, and thalamus, but not in the striatum. Results from Western blotting and immunocytochemistry experiments showed a significant reduction in collagen IV in the cortex and hippocampus with age and a reduction in laminin and nidogen 2 in the cortex and striatum. Injection of soluble Aβ into the hippocampus or thalamus showed an age-related reduction in perivascular drainage from the hippocampus but not from the thalamus. The results of the study suggest that changes in vascular basement membranes and perivascular drainage with age differ between brain regions, in the mouse, in a manner that may help to explain the differential deposition of Aβ in the brain in AD and may facilitate development of improved therapeutic strategies to remove Aβ from the brain in AD. © 2013 The Authors Aging Cell © 2013 Blackwell Publishing Ltd/Anatomical Society of Great Britain and Ireland.

Regional cerebral blood flow for singers and nonsingers while speaking, singing, and humming a rote passage

DOE Office of Scientific and Technical Information (OSTI.GOV)

Formby, C.; Thomas, R.G.; Halsey, J.H. Jr.

1989-05-01

Two groups of singers (n = 12,13) and a group of nonsingers (n = 12) each produced the national anthem by (1) speaking and (2) singing the words and by (3) humming the melody. Regional cerebral blood flow (rCBF) was measured at rest and during each phonation task from seven areas in each hemisphere by the {sup 133}Xe-inhalation method. Intrahemisphere, interhemisphere, and global rCBF were generally similar across phonation tasks and did not yield appreciable differences among the nonsingers and the singers.

Regional cerebral blood flow for singers and nonsingers while speaking, singing, and humming a rote passage.

PubMed

Formby, C; Thomas, R G; Halsey, J H

1989-05-01

Two groups of singers (n = 12,13) and a group of nonsingers (n = 12) each produced the national anthem by (1) speaking and (2) singing the words and by (3) humming the melody. Regional cerebral blood flow (rCBF) was measured at rest and during each phonation task from seven areas in each hemisphere by the 133Xe-inhalation method. Intrahemisphere, interhemisphere, and global rCBF were generally similar across phonation tasks and did not yield appreciable differences among the nonsingers and the singers.

Evaluation of cerebral ischemia using near-infrared spectroscopy with oxygen inhalation

NASA Astrophysics Data System (ADS)

Ebihara, Akira; Tanaka, Yuichi; Konno, Takehiko; Kawasaki, Shingo; Fujiwara, Michiyuki; Watanabe, Eiju

2012-09-01

Conventional methods presently used to evaluate cerebral hemodynamics are invasive, require physical restraint, and employ equipment that is not easily transportable. Therefore, it is difficult to take repeated measurements at the patient's bedside. An alternative method to evaluate cerebral hemodynamics was developed using near-infrared spectroscopy (NIRS) with oxygen inhalation. The bilateral fronto-temporal areas of 30 normal volunteers and 33 patients with cerebral ischemia were evaluated with the NIRS system. The subjects inhaled oxygen through a mask for 2 min at a flow rate of 8 L/min. Principal component analysis (PCA) was applied to the data, and a topogram was drawn using the calculated weights. NIRS findings were compared with those of single-photon-emission computed tomography (SPECT). In normal volunteers, no laterality of the PCA weights was observed in 25 of 30 cases (83%). In patients with cerebral ischemia, PCA weights in ischemic regions were lower than in normal regions. In 28 of 33 patients (85%) with cerebral ischemia, NIRS findings agreed with those of SPECT. The results suggest that transmission of the changes in systemic SpO2 were attenuated in ischemic regions. The method discussed here should be clinically useful because it can be used to measure cerebral ischemia easily, repeatedly, and noninvasively.

Acute and chronic head-down tail suspension diminishes cerebral perfusion in rats

NASA Technical Reports Server (NTRS)

Wilkerson, M. Keith; Colleran, Patrick N.; Delp, Michael D.

2002-01-01

The purpose of this study was to test the hypothesis that regional brain blood flow and vascular resistance are altered by acute and chronic head-down tail suspension (HDT). Regional cerebral blood flow, arterial pressure, heart rate, and vascular resistance were measured in a group of control rats during normal standing and following 10 min of HDT and in two other groups of rats after 7 and 28 days of HDT. Heart rate was not different among conditions, whereas mean arterial pressure was elevated at 10 min of HDT relative to the other conditions. Total brain blood flow was reduced from that during standing by 48, 24, and 27% following 10 min and 7 and 28 days of HDT, respectively. Regional blood flows to all cerebral tissues and the eyes were reduced with 10 min of HDT and remained lower in the eye, olfactory bulbs, left and right cerebrum, thalamic region, and the midbrain with 7 and 28 days of HDT. Total brain vascular resistance was 116, 44, and 38% greater following 10 min and 7 and 28 days of HDT, respectively, relative to that during control standing. Vascular resistance was elevated in all cerebral regions with 10 min of HDT and remained higher than control levels in most brain regions. These results demonstrate that HDT results in chronic elevations in total and regional cerebral vascular resistance, and this may be the underlying stimulus for the HDT-induced smooth muscle hypertrophy of cerebral resistance arteries.

Higher cerebral oxygen saturation may provide higher urinary output during continuous regional cerebral perfusion.

PubMed

Miyamoto, Takashi; Miyaji, Kagami; Okamoto, Hirotsugu; Kohira, Satoshi; Tomoyasu, Takahiro; Inoue, Nobuyuki; Ohara, Kuniyoshi

2008-10-31

We examined the hypothesis that higher cerebral oxygen saturation (rSO2) during RCP is correlated with urinary output. Between December 2002 and August 2006, 12 patients aged 3 to 61 days and weighing 2.6 to 3.4 kg underwent aortic arch repair with RCP. Urinary output and rSO2 were analyzed retrospectively. Data were assigned to either of 2 groups according to their corresponding rSO2: Group A (rSO2 < or = 75%) and Group B (rSO2 < 75%). Seven and 5 patients were assigned to Group A and Group B, respectively.Group A was characterized by mean radial arterial pressure (37.9 +/- 9.6 vs 45.8 +/- 7.8 mmHg; P = 0.14) and femoral arterial pressure (6.7 +/- 6.1 vs 20.8 +/- 14.6 mmHg; P = 0.09) compared to Group B. However, higher urinary output during CPB (1.03 +/- 1.18 vs 0.10 +/- 0.15 ml.kg-1.h-1; P = 0.03). Furthermore our results indicate that a higher dose of Chlorpromazine was used in Group A (2.9 +/- 1.4 vs 1.7 +/- 1.0 mg/kg; P = 0.03). Higher cerebral oxygenation may provide higher urinary output due to higher renal blood flow through collateral circulation.

Quantifying the Influence of Dynamics Across Scales on Regional Climate Uncertainty in Western North America

NASA Astrophysics Data System (ADS)

Goldenson, Naomi L.

Uncertainties in climate projections at the regional scale are inevitably larger than those for global mean quantities. Here, focusing on western North American regional climate, several approaches are taken to quantifying uncertainties starting with the output of global climate model projections. Internal variance is found to be an important component of the projection uncertainty up and down the west coast. To quantify internal variance and other projection uncertainties in existing climate models, we evaluate different ensemble configurations. Using a statistical framework to simultaneously account for multiple sources of uncertainty, we find internal variability can be quantified consistently using a large ensemble or an ensemble of opportunity that includes small ensembles from multiple models and climate scenarios. The latter offers the advantage of also producing estimates of uncertainty due to model differences. We conclude that climate projection uncertainties are best assessed using small single-model ensembles from as many model-scenario pairings as computationally feasible. We then conduct a small single-model ensemble of simulations using the Model for Prediction Across Scales with physics from the Community Atmosphere Model Version 5 (MPAS-CAM5) and prescribed historical sea surface temperatures. In the global variable resolution domain, the finest resolution (at 30 km) is in our region of interest over western North America and upwind over the northeast Pacific. In the finer-scale region, extreme precipitation from atmospheric rivers (ARs) is connected to tendencies in seasonal snowpack in mountains of the Northwest United States and California. In most of the Cascade Mountains, winters with more AR days are associated with less snowpack, in contrast to the northern Rockies and California's Sierra Nevadas. In snowpack observations and reanalysis of the atmospheric circulation, we find similar relationships between frequency of AR events and winter

Impaired cerebral autoregulation and brain injury in newborns with hypoxic-ischemic encephalopathy treated with hypothermia.

PubMed

Massaro, An N; Govindan, R B; Vezina, Gilbert; Chang, Taeun; Andescavage, Nickie N; Wang, Yunfei; Al-Shargabi, Tareq; Metzler, Marina; Harris, Kari; du Plessis, Adre J

2015-08-01

Impaired cerebral autoregulation may contribute to secondary injury in newborns with hypoxic-ischemic encephalopathy (HIE). Continuous, noninvasive assessment of cerebral pressure autoregulation can be achieved with bedside near-infrared spectroscopy (NIRS) and systemic mean arterial blood pressure (MAP) monitoring. This study aimed to evaluate whether impaired cerebral autoregulation measured by NIRS-MAP monitoring during therapeutic hypothermia and rewarming relates to outcome in 36 newborns with HIE. Spectral coherence analysis between NIRS and MAP was used to quantify changes in the duration [pressure passivity index (PPI)] and magnitude (gain) of cerebral autoregulatory impairment. Higher PPI in both cerebral hemispheres and gain in the right hemisphere were associated with neonatal adverse outcomes [death or detectable brain injury by magnetic resonance imaging (MRI), P < 0.001]. NIRS-MAP monitoring of cerebral autoregulation can provide an ongoing physiological biomarker that may help direct care in perinatal brain injury. Copyright © 2015 the American Physiological Society.

Defining ischemic burden after traumatic brain injury using 15O PET imaging of cerebral physiology.

PubMed

Coles, Jonathan P; Fryer, Tim D; Smielewski, Peter; Rice, Kenneth; Clark, John C; Pickard, John D; Menon, David K

2004-02-01

Whereas postmortem ischemic damage is common in head injury, antemortem demonstration of ischemia has proven to be elusive. Although 15O positron emission tomography may be useful in this area, the technique has traditionally analyzed data within regions of interest (ROIs) to improve statistical accuracy. In head injury, such techniques are limited because of the lack of a priori knowledge regarding the location of ischemia, coexistence of hyperaemia, and difficulty in defining ischemic cerebral blood flow (CBF) and cerebral oxygen metabolism (CMRO2) levels. We report a novel method for defining disease pathophysiology following head injury. Voxel-based approaches are used to define the distribution of oxygen extraction fraction (OEF) across the entire brain; the standard deviation of this distribution provides a measure of the variability of OEF. These data are also used to integrate voxels above a threshold OEF value to produce an ROI based upon coherent physiology rather than spatial contiguity (the ischemic brain volume; IBV). However, such approaches may suffer from poor statistical accuracy, particularly in regions with low blood flow. The magnitude of these errors has been assessed in modeling experiments using the Hoffman brain phantom and modified control datasets. We conclude that this technique is a valid and useful tool for quantifying ischemic burden after traumatic brain injury.

Network architecture of the cerebral nuclei (basal ganglia) association and commissural connectome.

PubMed

Swanson, Larry W; Sporns, Olaf; Hahn, Joel D

2016-10-04

The cerebral nuclei form the ventral division of the cerebral hemisphere and are thought to play an important role in neural systems controlling somatic movement and motivation. Network analysis was used to define global architectural features of intrinsic cerebral nuclei circuitry in one hemisphere (association connections) and between hemispheres (commissural connections). The analysis was based on more than 4,000 reports of histologically defined axonal connections involving all 45 gray matter regions of the rat cerebral nuclei and revealed the existence of four asymmetrically interconnected modules. The modules form four topographically distinct longitudinal columns that only partly correspond to previous interpretations of cerebral nuclei structure-function organization. The network of connections within and between modules in one hemisphere or the other is quite dense (about 40% of all possible connections), whereas the network of connections between hemispheres is weak and sparse (only about 5% of all possible connections). Particularly highly interconnected regions (rich club and hubs within it) form a topologically continuous band extending through two of the modules. Connection path lengths among numerous pairs of regions, and among some of the network's modules, are relatively long, thus accounting for low global efficiency in network communication. These results provide a starting point for reexamining the connectional organization of the cerebral hemispheres as a whole (right and left cerebral cortex and cerebral nuclei together) and their relation to the rest of the nervous system.

Network architecture of the cerebral nuclei (basal ganglia) association and commissural connectome

PubMed Central

Swanson, Larry W.; Sporns, Olaf; Hahn, Joel D.

2016-01-01

The cerebral nuclei form the ventral division of the cerebral hemisphere and are thought to play an important role in neural systems controlling somatic movement and motivation. Network analysis was used to define global architectural features of intrinsic cerebral nuclei circuitry in one hemisphere (association connections) and between hemispheres (commissural connections). The analysis was based on more than 4,000 reports of histologically defined axonal connections involving all 45 gray matter regions of the rat cerebral nuclei and revealed the existence of four asymmetrically interconnected modules. The modules form four topographically distinct longitudinal columns that only partly correspond to previous interpretations of cerebral nuclei structure–function organization. The network of connections within and between modules in one hemisphere or the other is quite dense (about 40% of all possible connections), whereas the network of connections between hemispheres is weak and sparse (only about 5% of all possible connections). Particularly highly interconnected regions (rich club and hubs within it) form a topologically continuous band extending through two of the modules. Connection path lengths among numerous pairs of regions, and among some of the network’s modules, are relatively long, thus accounting for low global efficiency in network communication. These results provide a starting point for reexamining the connectional organization of the cerebral hemispheres as a whole (right and left cerebral cortex and cerebral nuclei together) and their relation to the rest of the nervous system. PMID:27647882

Human cerebral autoregulation before, during and after spaceflight.

PubMed

Iwasaki, Ken-ichi; Levine, Benjamin D; Zhang, Rong; Zuckerman, Julie H; Pawelczyk, James A; Diedrich, André; Ertl, Andrew C; Cox, James F; Cooke, William H; Giller, Cole A; Ray, Chester A; Lane, Lynda D; Buckey, Jay C; Baisch, Friedhelm J; Eckberg, Dwain L; Robertson, David; Biaggioni, Italo; Blomqvist, C Gunnar

2007-03-15

Exposure to microgravity alters the distribution of body fluids and the degree of distension of cranial blood vessels, and these changes in turn may provoke structural remodelling and altered cerebral autoregulation. Impaired cerebral autoregulation has been documented following weightlessness simulated by head-down bed rest in humans, and is proposed as a mechanism responsible for postspaceflight orthostatic intolerance. In this study, we tested the hypothesis that spaceflight impairs cerebral autoregulation. We studied six astronauts approximately 72 and 23 days before, after 1 and 2 weeks in space (n = 4), on landing day, and 1 day after the 16 day Neurolab space shuttle mission. Beat-by-beat changes of photoplethysmographic mean arterial pressure and transcranial Doppler middle cerebral artery blood flow velocity were measured during 5 min of spontaneous breathing, 30 mmHg lower body suction to simulate standing in space, and 10 min of 60 deg passive upright tilt on Earth. Dynamic cerebral autoregulation was quantified by analysis of the transfer function between spontaneous changes of mean arterial pressure and cerebral artery blood flow velocity, in the very low- (0.02-0.07 Hz), low- (0.07-0.20 Hz) and high-frequency (0.20-0.35 Hz) ranges. Resting middle cerebral artery blood flow velocity did not change significantly from preflight values during or after spaceflight. Reductions of cerebral blood flow velocity during lower body suction were significant before spaceflight (P < 0.05, repeated measures ANOVA), but not during or after spaceflight. Absolute and percentage reductions of mean (+/- s.e.m.) cerebral blood flow velocity after 10 min upright tilt were smaller after than before spaceflight (absolute, -4 +/- 3 cm s(-1) after versus -14 +/- 3 cm s(-1) before, P = 0.001; and percentage, -8.0 +/- 4.8% after versus -24.8 +/- 4.4% before, P < 0.05), consistent with improved rather than impaired cerebral blood flow regulation. Low-frequency gain decreased

Enhanced contractility of intraparenchymal arterioles after global cerebral ischaemia in rat - new insights into the development of delayed cerebral hypoperfusion.

PubMed

Spray, S; Johansson, S E; Radziwon-Balicka, A; Haanes, K A; Warfvinge, K; Povlsen, G K; Kelly, P A T; Edvinsson, L

2017-08-01

Delayed cerebral hypoperfusion is a secondary complication found in the days after transient global cerebral ischaemia that worsens the ischaemic damage inflicted by the initial transient episode of global cerebral ischaemia. A recent study demonstrated increased cerebral vasoconstriction in the large arteries on the brain surface (pial arteries) after global cerebral ischaemia. However, smaller arterioles inside the brain (parenchymal arterioles) are equally important in the regulation of cerebral blood flow and yet their pathophysiology after global cerebral ischaemia is largely unknown. Therefore, we investigated whether increased contractility occurs in the intraparenchymal arterioles. Global cerebral ischaemia was induced in male Wistar rats by bilateral common carotid occlusion for 15 min combined with hypovolaemia. Regional cerebral blood flow was determined by quantitative autoradiography. Intraparenchymal arterioles were isolated and pressurized, and concentration-response curves to endothelin-1 with and without the endothelin B receptor-selective antagonist BQ788 was generated. Endothelin B receptor expression was investigated by quantitative flow cytometry and immunohistochemistry. We observed increased endothelin-1-mediated contractility of parenchymal arterioles correlating with reduced cerebral blood flow of the cortex, hippocampus and caudate nucleus 48 h after global cerebral ischaemia. The increased endothelin-1-mediated contractility was abolished by BQ788, and the vascular smooth muscle cell-specific expression of endothelin B receptors was significantly increased after global cerebral ischaemia. Increased endothelin-1-mediated contractility and expression of endothelin B receptors in the intraparenchymal vasculature contributes to the development of delayed cerebral hypoperfusion after global cerebral ischaemia in combination with vascular changes of the pial vasculature. © 2016 Scandinavian Physiological Society. Published by John Wiley

Temporal lobe interictal epileptic discharges affect cerebral activity in “default mode” brain regions

PubMed Central

Laufs, Helmut; Hamandi, Khalid; Salek-Haddadi, Afraim; Kleinschmidt, Andreas K; Duncan, John S; Lemieux, Louis

2007-01-01

A cerebral network comprising precuneus, medial frontal, and temporoparietal cortices is less active both during goal-directed behavior and states of reduced consciousness than during conscious rest. We tested the hypothesis that the interictal epileptic discharges affect activity in these brain regions in patients with temporal lobe epilepsy who have complex partial seizures. At the group level, using electroencephalography-correlated functional magnetic resonance imaging in 19 consecutive patients with focal epilepsy, we found common decreases of resting state activity in 9 patients with temporal lobe epilepsy (TLE) but not in 10 patients with extra-TLE. We infer that the functional consequences of TLE interictal epileptic discharges are different from those in extra-TLE and affect ongoing brain function. Activity increases were detected in the ipsilateral hippocampus in patients with TLE, and in subthalamic, bilateral superior temporal and medial frontal brain regions in patients with extra-TLE, possibly indicating effects of different interictal epileptic discharge propagation. PMID:17133385

The neurobiology of glucocerebrosidase-associated parkinsonism: a positron emission tomography study of dopamine synthesis and regional cerebral blood flow.

PubMed

Goker-Alpan, Ozlem; Masdeu, Joseph C; Kohn, Philip D; Ianni, Angela; Lopez, Grisel; Groden, Catherine; Chapman, Molly C; Cropp, Brett; Eisenberg, Daniel P; Maniwang, Emerson D; Davis, Joie; Wiggs, Edythe; Sidransky, Ellen; Berman, Karen F

2012-08-01

Mutations in GBA, the gene encoding glucocerebrosidase, the enzyme deficient in Gaucher disease, are common risk factors for Parkinson disease, as patients with Parkinson disease are over five times more likely to carry GBA mutations than healthy controls. Patients with GBA mutations generally have an earlier onset of Parkinson disease and more cognitive impairment than those without GBA mutations. We investigated whether GBA mutations alter the neurobiology of Parkinson disease, studying brain dopamine synthesis and resting regional cerebral blood flow in 107 subjects (38 women, 69 men). We measured dopamine synthesis with (18)F-fluorodopa positron emission tomography, and resting regional cerebral blood flow with H(2)(15)O positron emission tomography in the wakeful, resting state in four study groups: (i) patients with Parkinson disease and Gaucher disease (n = 7, average age = 56.6 ± 9.2 years); (ii) patients with Parkinson disease without GBA mutations (n = 11, 62.1 ± 7.1 years); (iii) patients with Gaucher disease without parkinsonism, but with a family history of Parkinson disease (n = 14, 52.6 ± 12.4 years); and (iv) healthy GBA-mutation carriers with a family history of Parkinson disease (n = 7, 50.1 ± 18 years). We compared each study group with a matched control group. Data were analysed with region of interest and voxel-based methods. Disease duration and Parkinson disease functional and staging scores were similar in the two groups with parkinsonism, as was striatal dopamine synthesis: both had greatest loss in the caudal striatum (putamen Ki loss: 44 and 42%, respectively), with less reduction in the caudate (20 and 18% loss). However, the group with both Parkinson and Gaucher diseases showed decreased resting regional cerebral blood flow in the lateral parieto-occipital association cortex and precuneus bilaterally. Furthermore, two subjects with Gaucher disease without parkinsonian manifestations showed diminished striatal dopamine. In conclusion

Correlated regions of cerebral blood flow with clinical parameters in Parkinson's disease; comparison using 'Anatomy' and 'Talairach Daemon' software.

PubMed

Yoon, Hyun Jin; Cheon, Sang Myung; Jeong, Young Jin; Kang, Do-Young

2012-02-01

We assign the anatomical names of functional activation regions in the brain, based on the probabilistic cyto-architectonic atlas by Anatomy 1.7 from an analysis of correlations between regional cerebral blood flow (rCBF) and clinical parameters of the non-demented Parkinson's disease (PD) patients by SPM8. We evaluated Anatomy 1.7 of SPM toolbox compared to 'Talairach Daemon' (TD) Client 2.4.2 software. One hundred and thirty-six patients (mean age 60.0 ± 9.09 years; 73 women and 63 men) with non-demented PD were selected. Tc-99m-HMPAO brain single-photon emission computed tomography (SPECT) scans were performed on the patients using a two-head gamma-camera. We analyzed the brain image of PD patients by SPM8 and found the anatomical names of correlated regions of rCBF perfusion with the clinical parameters using TD Client 2.4.2 and Anatomy 1.7. The SPM8 provided a correlation coefficient between clinical parameters and cerebral hypoperfusion by a simple regression method. To the clinical parameters were added age, duration of disease, education period, Hoehn and Yahr (H&Y) stage and Korean mini-mental state examination (K-MMSE) score. Age was correlated with cerebral perfusion in the Brodmann area (BA) 6 and BA 3b assigned by Anatomy 1.7 and BA 6 and pyramis in gray matter by TD Client 2.4.2 with p < 0.001 uncorrected. Also, assigned significant correlated regions were found in the left and right lobules VI (Hem) with duration of disease, in left and right lobules VIIa crus I (Hem) with education, in left insula (Ig2), left and right lobules VI (Hem) with H&Y, and in BA 4a and 6 with K-MMSE score with p < 0.05 uncorrected by Anatomy 1.7, respectively. Most areas of correlation were overlapped by two different anatomical labeling methods, but some correlation areas were found with different names. Age was the most significantly correlated clinical parameter with rCBF. TD Client found the exact anatomical name by the peak intensity position of the cluster while

The neurobiology of glucocerebrosidase-associated parkinsonism: a positron emission tomography study of dopamine synthesis and regional cerebral blood flow

PubMed Central

Goker-Alpan, Ozlem; Masdeu, Joseph C.; Kohn, Philip D.; Ianni, Angela; Lopez, Grisel; Groden, Catherine; Chapman, Molly C.; Cropp, Brett; Eisenberg, Daniel P.; Maniwang, Emerson D.; Davis, Joie; Wiggs, Edythe; Berman, Karen F.

2012-01-01

Mutations in GBA, the gene encoding glucocerebrosidase, the enzyme deficient in Gaucher disease, are common risk factors for Parkinson disease, as patients with Parkinson disease are over five times more likely to carry GBA mutations than healthy controls. Patients with GBA mutations generally have an earlier onset of Parkinson disease and more cognitive impairment than those without GBA mutations. We investigated whether GBA mutations alter the neurobiology of Parkinson disease, studying brain dopamine synthesis and resting regional cerebral blood flow in 107 subjects (38 women, 69 men). We measured dopamine synthesis with 18F-fluorodopa positron emission tomography, and resting regional cerebral blood flow with H215O positron emission tomography in the wakeful, resting state in four study groups: (i) patients with Parkinson disease and Gaucher disease (n = 7, average age = 56.6 ± 9.2 years); (ii) patients with Parkinson disease without GBA mutations (n = 11, 62.1 ± 7.1 years); (iii) patients with Gaucher disease without parkinsonism, but with a family history of Parkinson disease (n = 14, 52.6 ± 12.4 years); and (iv) healthy GBA-mutation carriers with a family history of Parkinson disease (n = 7, 50.1 ± 18 years). We compared each study group with a matched control group. Data were analysed with region of interest and voxel-based methods. Disease duration and Parkinson disease functional and staging scores were similar in the two groups with parkinsonism, as was striatal dopamine synthesis: both had greatest loss in the caudal striatum (putamen Ki loss: 44 and 42%, respectively), with less reduction in the caudate (20 and 18% loss). However, the group with both Parkinson and Gaucher diseases showed decreased resting regional cerebral blood flow in the lateral parieto-occipital association cortex and precuneus bilaterally. Furthermore, two subjects with Gaucher disease without parkinsonian manifestations showed diminished striatal dopamine. In conclusion, the

Imaging putative foetal cerebral blood oxygenation using susceptibility weighted imaging (SWI).

PubMed

Yadav, Brijesh Kumar; Krishnamurthy, Uday; Buch, Sagar; Jella, Pavan; Hernandez-Andrade, Edgar; Yeo, Lami; Korzeniewski, Steven J; Trifan, Anabela; Hassan, Sonia S; Haacke, E Mark; Romero, Roberto; Neelavalli, Jaladhar

2018-05-01

To evaluate the magnetic susceptibility, ∆χ v , as a surrogate marker of venous blood oxygen saturation, S v O 2 , in second- and third-trimester normal human foetuses. Thirty-six pregnant women, having a mean gestational age (GA) of 31 2/7 weeks, underwent magnetic resonance imaging (MRI). Susceptibility-weighted imaging (SWI) data from the foetal brain were acquired. ∆χ v of the superior sagittal sinus (SSS) was quantified using MR susceptometry from the intra-vascular phase measurements. Assuming the magnetic property of foetal blood, ∆χ do , is the same as that of adult blood, S v O 2 was derived from the measured Δχ v . The variation of ∆χ v and S v O 2 , as a function of GA, was statistically evaluated. The mean ∆χ v in the SSS in the second-trimester (n = 8) and third-trimester foetuses (n = 28) was found to be 0.34± 0.06 ppm and 0.49 ±0.05 ppm, respectively. Correspondingly, the derived S v O 2 values were 69.4% ±3.27% and 62.6% ±3.25%. Although not statistically significant, an increasing trend (p = 0.08) in Δχ v and a decreasing trend (p = 0.22) in S v O 2 with respect to advancing gestation was observed. We report cerebral venous blood magnetic susceptibility and putative oxygen saturation in healthy human foetuses. Cerebral oxygen saturation in healthy human foetuses, despite a slight decreasing trend, does not change significantly with advancing gestation. • Cerebral venous magnetic susceptibility and oxygenation in human foetuses can be quantified. • Cerebral venous oxygenation was not different between second- and third-trimester foetuses. • Foetal cerebral venous oxygenation does not change significantly with advancing gestation.

[Inferior frontal region hypoperfusion in Parkinson disease with dementia].

PubMed

Ochudło, Stanisław; Opala, Grzegorz; Jasińska-Myga, Barbara; Siuda, Joanna; Nowak, Stanisław

2003-01-01

Dementia is more frequent in patients suffering from Parkinson's disease (PD) then in general population. The mechanism for mental deterioration in PD remains controversial. The aim of our study was comparison of the regional cerebral perfusion quantified by single photon emission computed tomography in patients suffering from idiopathic Parkinson's disease with and without dementia. We examined 49 PD patients: 22 PD patients with dementia and 27 PD patients without dementia. Dementia was recognized according to ICD-10 and DSM-IV criteria. Cognitive functions were executed by means of the Mini Mental State Examination (MMSE) and neuropsychological assessment. The Unified Parkinson's Disease Rating Scale (UPDRS) and Modified Hoehn & Yahr Scale was used to quantify the severity of PD. SPECT was performed with Siemens Diacam single--head rotating gamma camera after intravenous application of technetium 99m hexamethylpropylene amine oxime (99mTc-HMPAO). The perfusion values were expressed as cortical or basal ganglia regions of interest (ROIs)/cerebellum activity ratios. In both examined group of patients the lowest uptake was in basal ganglia region, while the highest uptake was in occipital region. In the subgroup of PD patients with dementia significant hypoperfusion affecting the inferior frontal cortices was observed. In Parkinson's disease with dementia hypoperfusion in inferior frontal region can be found.

Quantifying the Contribution of Regional Aquifers to Stream Flow in the Upper Colorado River Basin

NASA Astrophysics Data System (ADS)

Masbruch, M.; Dickinson, J.

2017-12-01

The growing population of the arid and semiarid southwestern U.S. relies on over-allocated surface water resources and poorly quantified groundwater resources. In the Upper Colorado River Basin, recent studies have found that about 50 percent of the surface water at U.S. Geological Survey (USGS) stream gages is derived from groundwater contributions as base flow. Prior USGS and other studies for the Colorado Plateau region have mainly examined groundwater and surface water as separate systems, and there has yet to be regional synthesis of groundwater availability in aquifers that contribute to surface water. A more physically based representation of groundwater flow could improve simulations of surface-water capture by groundwater pumping, and changes of groundwater discharge to surface water caused by possible shifts in the distribution, magnitude, and timing of recharge in the future. We seek to improve conceptual and numerical models of groundwater and surface-water interactions in the Colorado Plateau region as part of a USGS regional groundwater availability assessment. Numerical modeling is used to simulate and quantify the base flow from groundwater to the Colorado River and its major tributaries. Groundwater/surface-water interactions will be simulated using the USGS code GSFLOW, which couples the Precipitation Runoff Modeling System (PRMS) to the groundwater flow model MODFLOW. Initial results suggest that interactions between groundwater and surface water are important for projecting long-term changes in surface water budgets.

Cerebral hemodynamic and metabolic changes caused by brain retraction after aneurysmal subarachnoid hemorrhage.

PubMed

Yundt, K D; Grubb, R L; Diringer, M N; Powers, W J

1997-03-01

The cerebral hemodynamic and metabolic effects of aneurysmal subarachnoid hemorrhage are complex. To investigate the impact of surgical retraction, we analyzed position emission tomography (PET) studies that measured the regional cerebral metabolic rate for oxygen, regional oxygen extraction fraction, and regional cerebral blood flow in four patients before and after right frontotemporal craniotomies for clipping of ruptured anterior circulation aneurysms. Preoperative studies were conducted 1 day before surgery and postoperative studies 6 to 17 days after surgery. No patient had hydrocephalus or intracerebral hematoma. At the time of the second PET study, none of the patients had signs of clinical vasospasm. Regional measurements were obtained from the right ventrolateral frontal and anterior temporal regions corresponding to the area of retraction and compared to the same regions in the opposite hemisphere. To establish a quantitative means to differentiate between hemodynamic and metabolic changes related to arterial vasospasm and those caused by brain retraction, we studied a second group of preoperative patients, who had undergone PET during angiographic and clinical vasospasm. There was a 45% reduction in regional cerebral metabolic rate for oxygen (1.87 +/- 0.22 to 1.04 +/- 0.28 ml 100 g-1 min-1) and 32% reduction in regional oxygen extraction fraction (0.41 +/- 0.04 to 0.28 +/- 0.03) in the region of retraction but no change in the opposite hemisphere (paired t test; P = 0.042 and 0.003, respectively). There was no change in regional cerebral blood flow in any region. Brain retraction produced a focal area of tissue injury at the site of retractor blade placement, as compared to more diffuse vascular territory changes produced by vasospasm. This reduction in the cerebral metabolic rate of oxygen and the oxygen extraction fraction indicates a primary reduction in metabolism and uncoupling of flow and metabolism (luxury perfusion). Similar findings of luxury

Higher cerebral oxygen saturation may provide higher urinary output during continuous regional cerebral perfusion

PubMed Central

Miyamoto, Takashi; Miyaji, Kagami; Okamoto, Hirotsugu; Kohira, Satoshi; Tomoyasu, Takahiro; Inoue, Nobuyuki; Ohara, Kuniyoshi

2008-01-01

Objective We examined the hypothesis that higher cerebral oxygen saturation (rSO2) during RCP is correlated with urinary output. Methods Between December 2002 and August 2006, 12 patients aged 3 to 61 days and weighing 2.6 to 3.4 kg underwent aortic arch repair with RCP. Urinary output and rSO2 were analyzed retrospectively. Data were assigned to either of 2 groups according to their corresponding rSO2: Group A (rSO2 ≦ 75%) and Group B (rSO2 < 75%). Results Seven and 5 patients were assigned to Group A and Group B, respectively. Group A was characterized by mean radial arterial pressure (37.9 ± 9.6 vs 45.8 ± 7.8 mmHg; P = 0.14) and femoral arterial pressure (6.7 ± 6.1 vs 20.8 ± 14.6 mmHg; P = 0.09) compared to Group B. However, higher urinary output during CPB (1.03 ± 1.18 vs 0.10 ± 0.15 ml·kg-1·h-1; P = 0.03). Furthermore our results indicate that a higher dose of Chlorpromazine was used in Group A (2.9 ± 1.4 vs 1.7 ± 1.0 mg/kg; P = 0.03). Conclusion Higher cerebral oxygenation may provide higher urinary output due to higher renal blood flow through collateral circulation. PMID:18973699

Hemodilution increases cerebral blood flow in acute ischemic stroke

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vorstrup, S.; Andersen, A.; Juhler, M.

1989-07-01

We measured cerebral blood flow in 10 consecutive, but selected, patients with acute ischemic stroke (less than 48 hours after onset) before and after hemodilution. Cerebral blood flow was measured by xenon-133 inhalation and emission tomography, and only patients with focal hypoperfusion in clinically relevant areas were included. Hemodilution was done according to the hematocrit level: for a hematocrit greater than or equal to 42%, 500 ml whole blood was drawn and replaced by the same volume of dextran 40; for a hematocrit between 37% and 42%, only 250 ml whole blood was drawn and replaced by 500 cc ofmore » dextran 40. Mean hematocrit was reduced by 16%, from 46 +/- 5% (SD) to 39 +/- 5% (SD) (p less than 0.001). Cerebral blood flow increased in both hemispheres by an average of 20.9% (p less than 0.001). Regional cerebral blood flow increased in the ischemic areas in all cases, on an average of 21.4 +/- 12.0% (SD) (p less than 0.001). In three patients, a significant redistribution of flow in favor of the hypoperfused areas was observed, and in six patients, the fractional cerebral blood flow increase in the hypoperfused areas was of the same magnitude as in the remainder of the brain. In the last patient, cerebral blood flow increased relatively less in the ischemic areas. Our findings show that cerebral blood flow increases in the ischemic areas after hemodilution therapy in stroke patients. The marked regional cerebral blood flow increase seen in some patients could imply an improved oxygen delivery to the ischemic tissue.« less

Measurement of regional cerebral blood flow with copper-62-PTSM and a three-compartment model.

PubMed

Okazawa, H; Yonekura, Y; Fujibayashi, Y; Mukai, T; Nishizawa, S; Magata, Y; Ishizu, K; Tamaki, N; Konishi, J

1996-07-01

We evaluated quantitatively 62Cu-labeled pyruvaldehyde bis(N4-methylthiosemicarbazone) copper II (62Cu-PTSM) as a brain perfusion tracer for positron emission tomography (PET). For quantitative measurement, the octanol extraction method is needed to correct for arterial radioactivity in estimating the lipophilic input function, but the procedure is not practical for clinical studies. To measure regional cerebral blood flow (rCBF) by 62Cu-PTSM with simple arterial blood sampling, a standard curve of the octanol extraction ratio and a three-compartment model were applied. We performed both 15O-labeled water PET and 62 Cu-PTSM PET with dynamic data acquisition and arterial sampling in six subjects. Data obtained in 10 subjects studied previously were used for the standard octanol extraction curve. Arterial activity was measured and corrected to obtain the true input function using the standard curve. Graphical analysis (Gjedde-Patlak plot) with the data for each subject fitted by a straight regression line suggested that 62Cu-PTSM can be analyzed by the three-compartment model with negligible K4. Using this model, K1-K3 were estimated from curve fitting of the cerebral time-activity curve and the corrected input function. The fractional uptake of 62Cu-PTSM was corrected to rCBF with the individual extraction at steady state calculated from K1-K3. The influx rates (Ki) obtained from three-compartment model and graphical analyses were compared for the validation of the model. A comparison of rCBF values obtained from 62Cu-PTSM and 150-water studies demonstrated excellent correlation. The results suggest the potential feasibility of quantitation of cerebral perfusion with 62Cu-PTSM accompanied by dynamic PET and simple arterial sampling.

Regional cerebral blood flow and cerebrovascular reactivity in Alzheimer's disease and vascular dementia assessed by arterial spinlabeling magnetic resonance imaging.

PubMed

Gao, Yong-Zhe; Zhang, Jun-Jian; Liu, Hui; Wu, Guang-Yao; Xiong, Li; Shu, Min

2013-02-01

Hemodynamic disturbance in cerebral blood flow (CBF) is common in both Alzheimer's disease (AD) and vascular dementia (VaD).The aim of this study is to investigate the different patterns of regional cerebral blood flow (rCBF) change and cerebrovascular reactivity (CVR) in these two types of dementia. Mean flow velocity (MFV) of middle cerebral artery and rCBF were measured by Transcranial Doppler ultrasound (TCD) and arterial spin-labeling (ASL) magnetic resonance, separately. CVR was evaluated by MFV or rCBF change in response to 5% CO2 inhalation. The ASL results showed that, rCBF was significantly lower in both the bilateral frontal and temporal lobes in AD group and lower in left frontal and temporal white matter in patients with VaD. CVR calculated by rCBF was impaired more severely in bilateral frontal cortices in AD. Conversely, TCD tests failed to demonstrate significant difference in MFV and CVR between the two groups. It is concluded that the different patterns detected by ASL in resting rCBF change and cerebrovascular reactivity in response to carbogen inhalation may serve as a potential marker to distinguish AD and VaD.

Histological quantification of brain tissue inflammatory cell infiltration after focal cerebral infarction: a systematic review.

PubMed

Russek, Natanya S; Jensen, Matthew B

2014-03-01

Ischemic stroke is a leading cause of death and disability, and current treatments to limit tissue injury and improve recovery are limited. Cerebral infarction is accompanied by intense brain tissue inflammation involving many inflammatory cell types that may cause both negative and positive effects on outcomes. Many potential neuroprotective and neurorestorative treatments may affect, and be affected by, this inflammatory cell infiltration, so that accurate quantification of this tissue response is needed. We performed a systematic review of histological methods to quantify brain tissue inflammatory cell infiltration after cerebral infarction. We found reports of multiple techniques to quantify different inflammatory cell types. We found no direct comparison studies and conclude that more research is needed to optimize the assessment of this important stroke outcome.

Orthogonal design to sift the optimal parameter of Neiguan acupuncture for cerebral infarction

PubMed Central

Zhang, Yanan; Yang, Sha; Fan, Xiaonong; Wang, Shu; He, Nina; Li, Lingxin; Luo, Ding; Shi, Xuemin

2013-01-01

The individual difference and non-repeatability in acupuncture have not only restricted the development of acupuncture, but have also affected the specificity of acupoints. The present study used instruments to control needle depth, lifting and thrusting frequency, and the duration of acupuncture. Effects of the quantified acupuncture were observed at Neiguan (PC6) with different stimulation parameters. A frequency of 1, 2, or 3 Hz and duration of 5, 60, or 180 seconds were used to observe cerebral blood flow and ratio of infarct volume recovery. Results showed that stimulation at Neiguan with a frequency of 1 Hz and long duration of 180 seconds or 2/3 Hz and long duration of 5/60 seconds significantly increased cerebral blood flow and decreased the ratio of infarct volume. Interactions between frequency and duration play a critical role in quantified acupuncture therapy. PMID:25206575

Modelling the effects of cerebral microvasculature morphology on oxygen transport.

PubMed

Park, Chang Sub; Payne, Stephen J

2016-01-01

The cerebral microvasculature plays a vital role in adequately supplying blood to the brain. Determining the health of the cerebral microvasculature is important during pathological conditions, such as stroke and dementia. Recent studies have shown the complex relationship between cerebral metabolic rate and transit time distribution, the transit times of all the possible pathways available dependent on network topology. In this paper, we extend a recently developed technique to solve for residue function, the amount of tracer left in the vasculature at any time, and transit time distribution in an existing model of the cerebral microvasculature to calculate cerebral metabolism. We present the mathematical theory needed to solve for oxygen concentration followed by results of the simulations. It is found that oxygen extraction fraction, the fraction of oxygen removed from the blood in the capillary network by the tissue, and cerebral metabolic rate are dependent on both mean and heterogeneity of the transit time distribution. For changes in cerebral blood flow, a positive correlation can be observed between mean transit time and oxygen extraction fraction, and a negative correlation between mean transit time and metabolic rate of oxygen. A negative correlation can also be observed between transit time heterogeneity and the metabolic rate of oxygen for a constant cerebral blood flow. A sensitivity analysis on the mean and heterogeneity of the transit time distribution was able to quantify their respective contributions to oxygen extraction fraction and metabolic rate of oxygen. Mean transit time has a greater contribution than the heterogeneity for oxygen extraction fraction. This is found to be opposite for metabolic rate of oxygen. These results provide information on the role of the cerebral microvasculature and its effects on flow and metabolism. They thus open up the possibility of obtaining additional valuable clinical information for diagnosing and treating

Quantifying Tropical Glacier Mass Balance Sensitivity to Climate Change Through Regional-Scale Modeling and The Randolph Glacier Inventory

NASA Astrophysics Data System (ADS)

Malone, A.

2017-12-01

Quantifying mass balance sensitivity to climate change is essential for forecasting glacier evolution and deciphering climate signals embedded in archives of past glacier changes. Ideally, these quantifications result from decades of field measurement, remote sensing, and a hierarchy modeling approach, but in data-sparse regions, such as the Himalayas and tropical Andes, regional-scale modeling rooted in first principles provides a first-order picture. Previous regional-scaling modeling studies have applied a surface energy and mass balance approach in order to quantify equilibrium line altitude sensitivity to climate change. In this study, an expanded regional-scale surface energy and mass balance model is implemented to quantify glacier-wide mass balance sensitivity to climate change for tropical Andean glaciers. Data from the Randolph Glacier Inventory are incorporated, and additional physical processes are included, such as a dynamic albedo and cloud-dependent atmospheric emissivity. The model output agrees well with the limited mass balance records for tropical Andean glaciers. The dominant climate variables driving interannual mass balance variability differ depending on the climate setting. For wet tropical glaciers (annual precipitation >0.75 m y-1), temperature is the dominant climate variable. Different hypotheses for the processes linking wet tropical glacier mass balance variability to temperature are evaluated. The results support the hypothesis that glacier-wide mass balance on wet tropical glaciers is largely dominated by processes at the lowest elevation where temperature plays a leading role in energy exchanges. This research also highlights the transient nature of wet tropical glaciers - the vast majority of tropical glaciers and a vital regional water resource - in an anthropogenic warming world.

Mannitol-facilitated perfusion staining with 2, 3, 5-triphenyltetrazolium chloride (TTC) for detection of experimental cerebral infarction and biochemical analysis

PubMed Central

Sun, Yu-Yo; Yang, Dianer; Kuan, Chia-Yi

2011-01-01

A simple method to quantify cerebral infarction has great value for mechanistic and therapeutic studies in experimental stroke research. Immersion staining of unfixed brain slices with 2,3,5-triphenyltetrazolium chloride (TTC) is a popular method to determine cerebral infarction in preclinical studies. However, it is often difficult to apply immersion TTC-labeling to severely injured or soft newborn brains in rodents. Here we report an in-vivo TTC perfusion-labeling method based on osmotic opening of blood-brain-barrier with mannitol-pretreatment. This new method delineates cortical infarction correlated with the boundary of morphological cell injury, differentiates the induction or subcellular redistribution of apoptosis-related factors between viable and damaged areas, and easily determines the size of cerebral infarction in both adult and newborn mice. Using this method, we confirmed that administration of lipopolysaccharide 72 h before hypoxia-ischemia increases the damage in neonatal mouse brains, in contrast to its effect of protective preconditioning in adults. These results demonstrate a fast and inexpensive method that simplifies the task of quantifying cerebral infarction in small or severely injured brains and assists biochemical analysis of experimental cerebral ischemia. PMID:21982741

Bimanual Force Coordination in Children with Spastic Unilateral Cerebral Palsy

ERIC Educational Resources Information Center

Smits-Engelsman, B. C. M.; Klingels, K.; Feys, H.

2011-01-01

In this study bimanual grip-force coordination was quantified using a novel "Gripper" system that records grip forces produced while holding a lower and upper unit, in combination with the lift force necessary to separate these units. Children with unilateral cerebral palsy (CP) (aged 5-14 years, n = 12) were compared to age matched typically…

An analysis of regional cerebral blood flow in impulsive murderers using single photon emission computed tomography.

PubMed

Amen, Daniel G; Hanks, Chris; Prunella, Jill R; Green, Aisa

2007-01-01

The authors explored differences in regional cerebral blood flow in 11 impulsive murderers and 11 healthy comparison subjects using single photon emission computed tomography. The authors assessed subjects at rest and during a computerized go/no-go concentration task. Using statistical parametric mapping software, the authors performed voxel-by-voxel t tests to assess significant differences, making family-wide error corrections for multiple comparisons. Murderers were found to have significantly lower relative rCBF during concentration, particularly in areas associated with concentration and impulse control. These results indicate that nonemotionally laden stimuli may result in frontotemporal dysregulation in people predisposed to impulsive violence.

Sleep-Wake Differences in Relative Regional Cerebral Metabolic Rate for Glucose among Patients with Insomnia Compared with Good Sleepers

PubMed Central

Kay, Daniel B.; Karim, Helmet T.; Soehner, Adriane M.; Hasler, Brant P.; Wilckens, Kristine A.; James, Jeffrey A.; Aizenstein, Howard J.; Price, Julie C.; Rosario, Bedda L.; Kupfer, David J.; Germain, Anne; Hall, Martica H.; Franzen, Peter L.; Nofzinger, Eric A.; Buysse, Daniel J.

2016-01-01

Study Objectives: The neurobiological mechanisms of insomnia may involve altered patterns of activation across sleep-wake states in brain regions associated with cognition, self-referential processes, affect, and sleep-wake promotion. The objective of this study was to compare relative regional cerebral metabolic rate for glucose (rCMRglc) in these brain regions across wake and nonrapid eye movement (NREM) sleep states in patients with primary insomnia (PI) and good sleeper controls (GS). Methods: Participants included 44 PI and 40 GS matched for age (mean = 37 y old, range 21–60), sex, and race. We conducted [18F]fluoro-2-deoxy-d-glucose positron emission tomography scans in PI and GS during both morning wakefulness and NREM sleep at night. Repeated measures analysis of variance was used to test for group (PI vs. GS) by state (wake vs. NREM sleep) interactions in relative rCMRglc. Results: Significant group-by-state interactions in relative rCMRglc were found in the precuneus/posterior cingulate cortex, left middle frontal gyrus, left inferior/superior parietal lobules, left lingual/fusiform/occipital gyri, and right lingual gyrus. All clusters were significant at Pcorrected < 0.05. Conclusions: Insomnia was characterized by regional alterations in relative glucose metabolism across NREM sleep and wakefulness. Significant group-by-state interactions in relative rCMRglc suggest that insomnia is associated with impaired disengagement of brain regions involved in cognition (left frontoparietal), self-referential processes (precuneus/posterior cingulate), and affect (left middle frontal, fusiform/lingual gyri) during NREM sleep, or alternatively, to impaired engagement of these regions during wakefulness. Citation: Kay DB, Karim HT, Soehner AM, Hasler BP, Wilckens KA, James JA, Aizenstein HJ, Price JC, Rosario BL, Kupfer DJ, Germain A, Hall MH, Franzen PL, Nofzinger EA, Buysse DJ. Sleep-wake differences in relative regional cerebral metabolic rate for glucose among

Mechanisms of murine cerebral malaria: Multimodal imaging of altered cerebral metabolism and protein oxidation at hemorrhage sites

PubMed Central

Hackett, Mark J.; Aitken, Jade B.; El-Assaad, Fatima; McQuillan, James A.; Carter, Elizabeth A.; Ball, Helen J.; Tobin, Mark J.; Paterson, David; de Jonge, Martin D.; Siegele, Rainer; Cohen, David D.; Vogt, Stefan; Grau, Georges E.; Hunt, Nicholas H.; Lay, Peter A.

2015-01-01

Using a multimodal biospectroscopic approach, we settle several long-standing controversies over the molecular mechanisms that lead to brain damage in cerebral malaria, which is a major health concern in developing countries because of high levels of mortality and permanent brain damage. Our results provide the first conclusive evidence that important components of the pathology of cerebral malaria include peroxidative stress and protein oxidation within cerebellar gray matter, which are colocalized with elevated nonheme iron at the site of microhemorrhage. Such information could not be obtained previously from routine imaging methods, such as electron microscopy, fluorescence, and optical microscopy in combination with immunocytochemistry, or from bulk assays, where the level of spatial information is restricted to the minimum size of tissue that can be dissected. We describe the novel combination of chemical probe–free, multimodal imaging to quantify molecular markers of disturbed energy metabolism and peroxidative stress, which were used to provide new insights into understanding the pathogenesis of cerebral malaria. In addition to these mechanistic insights, the approach described acts as a template for the future use of multimodal biospectroscopy for understanding the molecular processes involved in a range of clinically important acute and chronic (neurodegenerative) brain diseases to improve treatment strategies. PMID:26824064

Influence of cerebrovascular resistance on the dynamic relationship between blood pressure and cerebral blood flow in humans.

PubMed

Smirl, J D; Tzeng, Y C; Monteleone, B J; Ainslie, P N

2014-06-15

We examined the hypothesis that changes in the cerebrovascular resistance index (CVRi), independent of blood pressure (BP), will influence the dynamic relationship between BP and cerebral blood flow in humans. We altered CVRi with (via controlled hyperventilation) and without [via indomethacin (INDO, 1.2 mg/kg)] changes in PaCO2. Sixteen subjects (12 men, 27 ± 7 yr) were tested on two occasions (INDO and hypocapnia) separated by >48 h. Each test incorporated seated rest (5 min), followed by squat-stand maneuvers to increase BP variability and improve assessment of the pressure-flow dynamics using linear transfer function analysis (TFA). Beat-to-beat BP, middle cerebral artery velocity (MCAv), posterior cerebral artery velocity (PCAv), and end-tidal Pco2 were monitored. Dynamic pressure-flow relations were quantified using TFA between BP and MCAv/PCAv in the very low and low frequencies through the driven squat-stand maneuvers at 0.05 and 0.10 Hz. MCAv and PCAv reductions by INDO and hypocapnia were well matched, and CVRi was comparably elevated (P < 0.001). During the squat-stand maneuvers (0.05 and 0.10 Hz), the point estimates of absolute gain were universally reduced, and phase was increased under both conditions. In addition to an absence of regional differences, our findings indicate that alterations in CVRi independent of PaCO2 can alter cerebral pressure-flow dynamics. These findings are consistent with the concept of CVRi being a key factor that should be considered in the correct interpretation of cerebral pressure-flow dynamics as indexed using TFA metrics. Copyright © 2014 the American Physiological Society.

T2’-Imaging to Assess Cerebral Oxygen Extraction Fraction in Carotid Occlusive Disease: Influence of Cerebral Autoregulation and Cerebral Blood Volume

PubMed Central

Deichmann, Ralf; Pfeilschifter, Waltraud; Hattingen, Elke; Singer, Oliver C.; Wagner, Marlies

2016-01-01

Purpose Quantitative T2'-mapping detects regional changes of the relation of oxygenated and deoxygenated hemoglobin (Hb) by using their different magnetic properties in gradient echo imaging and might therefore be a surrogate marker of increased oxygen extraction fraction (OEF) in cerebral hypoperfusion. Since elevations of cerebral blood volume (CBV) with consecutive accumulation of Hb might also increase the fraction of deoxygenated Hb and, through this, decrease the T2’-values in these patients we evaluated the relationship between T2’-values and CBV in patients with unilateral high-grade large-artery stenosis. Materials and Methods Data from 16 patients (13 male, 3 female; mean age 53 years) with unilateral symptomatic or asymptomatic high-grade internal carotid artery (ICA) or middle cerebral artery (MCA) stenosis/occlusion were analyzed. MRI included perfusion-weighted imaging and high-resolution T2’-mapping. Representative relative (r)CBV-values were analyzed in areas of decreased T2’ with different degrees of perfusion delay and compared to corresponding contralateral areas. Results No significant elevations in cerebral rCBV were detected within areas with significantly decreased T2’-values. In contrast, rCBV was significantly decreased (p<0.05) in regions with severe perfusion delay and decreased T2’. Furthermore, no significant correlation between T2’- and rCBV-values was found. Conclusions rCBV is not significantly increased in areas of decreased T2’ and in areas of restricted perfusion in patients with unilateral high-grade stenosis. Therefore, T2’ should only be influenced by changes of oxygen metabolism, regarding our patient collective especially by an increase of the OEF. T2’-mapping is suitable to detect altered oxygen consumption in chronic cerebrovascular disease. PMID:27560515

Analysis of dynamic cerebral autoregulation using an ARX model based on arterial blood pressure and middle cerebral artery velocity simulation.

PubMed

Liu, Y; Allen, R

2002-09-01

The study aimed to model the cerebrovascular system, using a linear ARX model based on data simulated by a comprehensive physiological model, and to assess the range of applicability of linear parametric models. Arterial blood pressure (ABP) and middle cerebral arterial blood flow velocity (MCAV) were measured from 11 subjects non-invasively, following step changes in ABP, using the thigh cuff technique. By optimising parameters associated with autoregulation, using a non-linear optimisation technique, the physiological model showed a good performance (r=0.83+/-0.14) in fitting MCAV. An additional five sets of measured ABP of length 236+/-154 s were acquired from a subject at rest. These were normalised and rescaled to coefficients of variation (CV=SD/mean) of 2% and 10% for model comparisons. Randomly generated Gaussian noise with standard deviation (SD) from 1% to 5% was added to both ABP and physiologically simulated MCAV (SMCAV), with 'normal' and 'impaired' cerebral autoregulation, to simulate the real measurement conditions. ABP and SMCAV were fitted by ARX modelling, and cerebral autoregulation was quantified by a 5 s recovery percentage R5% of the step responses of the ARX models. The study suggests that cerebral autoregulation can be assessed by computing the R5% of the step response of an ARX model of appropriate order, even when measurement noise is considerable.

The effect of amphetamine on regional cerebral blood flow during cognitive activation in schizophrenia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Daniel, D.G.; Weinberger, D.R.; Jones, D.W.

1991-07-01

To explore the role of monoamines on cerebral function during specific prefrontal cognitive activation, we conducted a double-blind placebo-controlled crossover study of the effects of 0.25 mg/kg oral dextroamphetamine on regional cerebral blood flow (rCBF) as determined by 133Xe dynamic single-photon emission-computed tomography (SPECT) during performance of the Wisconsin Card Sorting Test (WCST) and a sensorimotor control task. Ten patients with chronic schizophrenia who had been stabilized for at least 6 weeks on 0.4 mg/kg haloperidol participated. Amphetamine produced a modest, nonsignificant, task-independent, global reduction in rCBF. However, the effect of amphetamine on task-dependent activation of rCBF (i.e., WCST minusmore » control task) was striking. Whereas on placebo no significant activation of rCBF was seen during the WCST compared with the control task, on amphetamine significant activation of the left dorsolateral prefrontal cortex (DLPFC) occurred (p = 0.0006). Both the mean number of correct responses and the mean conceptual level increased (p less than 0.05) with amphetamine relative to placebo. In addition, with amphetamine, but not with placebo, a significant correlation (p = -0.71; p less than 0.05) emerged between activation of DLPFC rCBF and performance of the WCST task. These findings are consistent with animal models in which mesocortical catecholaminergic activity modulates and enhances the signal-to-noise ratio of evoked cortical activity.« less

Improved power for characterizing longitudinal amyloid-β PET changes and evaluating amyloid-modifying treatments with a cerebral white matter reference region.

PubMed

Chen, Kewei; Roontiva, Auttawut; Thiyyagura, Pradeep; Lee, Wendy; Liu, Xiaofen; Ayutyanont, Napatkamon; Protas, Hillary; Luo, Ji Luo; Bauer, Robert; Reschke, Cole; Bandy, Daniel; Koeppe, Robert A; Fleisher, Adam S; Caselli, Richard J; Landau, Susan; Jagust, William J; Weiner, Michael W; Reiman, Eric M

2015-04-01

In this article, we describe an image analysis strategy with improved power for tracking longitudinal amyloid-β (Aβ) PET changes and evaluating Aβ-modifying treatments. Our aims were to compare the power of template-based cerebellar, pontine, and cerebral white matter reference regions to track 24-mo florbetapir standardized uptake value (SUV) ratio (SUVR) changes; to relate those changes to 24-mo clinical declines; and to evaluate Aβ-modifying treatments in Aβ-positive (Aβ+) and Aβ-negative (Aβ-) patients with probable Alzheimer dementia (pAD), in patients with mild cognitive impairment (MCI), in cognitively normal controls (NCs), and in cognitively normal apolipoprotein E4 (APOE4) carriers and noncarriers. We used baseline and follow-up (∼24 mo) florbetapir PET scans from 332 Aβ+ and Aβ- subjects participating in the multicenter Alzheimer's Disease Neuroimaging Initiative. Each of the proposed analyses included 31 pAD patients, 187 MCI patients, and 114 NCs. Cerebral-to-white matter, cerebellar, and pontine SUVRs were characterized in terms of their longitudinal variability; their power to track longitudinal fibrillar Aβ increases in Aβ+ and Aβ- subgroups and cognitively normal APOE4 carriers and noncarriers; the sample sizes needed to detect attenuated accumulation of or clearance of fibrillar Aβ accumulation in randomized clinical trials; and their ability to relate 24-mo fibrillar Aβ increases to clinical declines. As predicted, cerebral-to-white matter SUVR changes were significantly less variable and had significantly greater power to detect 24-mo fibrillar Aβ increases and evaluate Aβ-modifying treatment effects in Aβ+ pAD, MCI, and NC subjects and cognitively normal APOE4 carriers. They were also distinguished by the ability to detect significant associations between 24-mo Aβ increases and clinical declines. A cerebral white matter reference region may improve the power to track longitudinal fibrillar Aβ increases, to characterize

Individual variability of cerebral autoregulation, posterior cerebral circulation and white matter hyperintensity.

PubMed

Liu, Jie; Tseng, Benjamin Y; Khan, Muhammad Ayaz; Tarumi, Takashi; Hill, Candace; Mirshams, Niki; Hodics, Timea M; Hynan, Linda S; Zhang, Rong

2016-06-01

Cerebral autoregulation (CA) is a key mechanism to protect brain perfusion in the face of changes in arterial blood pressure, but little is known about individual variability of CA and its relationship to the presence of brain white matter hyperintensity (WMH) in older adults, a type of white matter lesion related to cerebral small vessel disease (SVD). This study demonstrated the presence of large individual variability of CA in healthy older adults during vasoactive drug-induced changes in arterial pressure assessed at the internal carotid and vertebral arteries. We also observed, unexpectedly, that it was the 'over-' rather than the 'less-reactive' CA measured at the vertebral artery that was associated with WMH severity. These findings challenge the traditional concept of CA and suggest that the presence of cerebral SVD, manifested as WMH, is associated with posterior brain hypoperfusion during acute increase in arterial pressure. This study measured the individual variability of static cerebral autoregulation (CA) and determined its associations with brain white matter hyperintensity (WMH) in older adults. Twenty-seven healthy older adults (13 females, 66 ± 6 years) underwent assessment of CA during steady-state changes in mean arterial pressure (MAP) induced by intravenous infusion of sodium nitroprusside (SNP) and phenylephrine. Cerebral blood flow (CBF) was measured using colour-coded duplex ultrasonography at the internal carotid (ICA) and vertebral arteries (VA). CA was quantified by a linear regression slope (CA slope) between percentage changes in cerebrovascular resistance (CVR = MAP/CBF) and MAP relative to baseline values. Periventricular and deep WMH volumes were measured with T2-weighted magnetic resonance imaging. MAP was reduced by -11 ± 7% during SNP, and increased by 21 ± 8% during phenylephrine infusion. CA demonstrated large individual variability with the CA slopes ranging from 0.37 to 2.20 at the ICA and from 0.17 to 3.18 at the

Anxiety and cerebral blood flow during behavioral challenge. Dissociation of central from peripheral and subjective measures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zohar, J.; Insel, T.R.; Berman, K.F.

1989-06-01

To investigate the relationship between anxiety and regional cerebral blood flow, we administered behavioral challenges to 10 patients with obsessive-compulsive disorder while measuring regional cerebral blood flow with the xenon 133 inhalation technique. Each patient was studied under three conditions: relaxation, imaginal flooding, and in vivo (actual) exposure to the phobic stimulus. Subjective anxiety, obsessive-compulsive ratings, and autonomic measures (heart rate, blood pressure) increased significantly, but respiratory rate and PCO/sub 2/ did not change across the three conditions. Regional cerebral blood flow increased slightly (in the temporal region) during imaginal flooding, but decreased markedly in several cortical regions during inmore » vivo exposure, when anxiety was highest by subjective and peripheral autonomic measures. These results demonstrate that intense anxiety can be associated with decreased rather than increased cortical perfusion and that ostensibly related states of anxiety (eg, anticipatory and obsessional anxiety) may be associated with opposite effects on regional cerebral blood flow.« less

Regional cerebral blood flow and abnormal eating behavior in Prader-Willi syndrome.

PubMed

Ogura, Kaeko; Fujii, Toshikatsu; Abe, Nobuhito; Hosokai, Yoshiyuki; Shinohara, Mayumi; Fukuda, Hiroshi; Mori, Etsuro

2013-05-01

Prader-Willi syndrome (PWS) is a genetically determined neurodevelopmental disorder and is generally regarded as a genetic model of obesity. Individuals with PWS exhibit behavioral symptoms including temper tantrums, rigid thinking, and compulsive behavior. The most striking feature of PWS is abnormal eating behavior, including hyperphagia, intense preoccupation with food, and incessant food seeking. To explore brain regions associated with the behavioral symptoms of PWS, we investigated differences in resting-state regional cerebral blood flow (rCBF) between individuals with PWS and healthy controls. Correlation analyses were also performed to examine the relationship between rCBF and altered eating behavior in PWS individuals. Twelve adults with PWS and 13 age- and gender-matched controls underwent resting-state single photon emission computerized tomography (SPECT) with N-isopropyl-p-[(123)I] iodoamphetamine (IMP). The rCBF data were analyzed on a voxel-by-voxel basis using SPM5 software. The results demonstrated that compared with controls, individuals with PWS had significantly lower rCBF in the right thalamus, left insular cortex, bilateral lingual gyrus, and bilateral cerebellum. They had significantly higher rCBF in the right inferior frontal gyrus, left middle/inferior frontal gyrus (anterior and posterior clusters), and bilateral angular gyrus. Additionally, rCBF in the left insula, which was significantly lower in PWS individuals, was negatively correlated with the eating behavior severity score. These results suggest that specific brain regions, particularly the left insula, may be partly responsible for the behavioral symptoms in PWS. Copyright © 2012 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

Mechanisms of Acupuncture Therapy for Cerebral Ischemia: an Evidence-Based Review of Clinical and Animal Studies on Cerebral Ischemia.

PubMed

Zhu, Wen; Ye, Yang; Liu, Yi; Wang, Xue-Rui; Shi, Guang-Xia; Zhang, Shuai; Liu, Cun-Zhi

2017-12-01

Ischemic stroke is a major cause of mortality and disability worldwide. As a part of Traditional Chinese Medicine (TCM), acupuncture has been shown to be effective in promoting recovery after stroke. In this article, we review the clinical and experimental studies that demonstrated the mechanisms of acupuncture treatment for cerebral ischemia. Clinical studies indicated that acupuncture activated relevant brain regions, modulated cerebral blood flow and related molecules in stroke patients. Evidence from laboratory indicated that acupuncture regulates cerebral blood flow and metabolism after the interrupt of blood supply. Acupuncture regulates multiple molecules and signaling pathways that lead to excitoxicity, oxidative stress, inflammation, neurons death and survival. Acupuncture also promotes neurogenesis, angiogenesis as well as neuroplasticity after ischemic damage. The evidence provided from clinical and laboratory suggests that acupuncture induces multi-level regulation via complex mechanisms and a single factor may not be enough to explain the beneficial effects against cerebral ischemia.

Comprehensive Quantification of the Spastic Catch in Children with Cerebral Palsy

ERIC Educational Resources Information Center

Lynn, Bar-On; Erwin, Aertbelien; Guy, Molenaers; Herman, Bruyninckx; Davide, Monari; Ellen, Jaspers; Anne, Cazaerck; Kaat, Desloovere

2013-01-01

In clinical settings, the spastic catch is judged subjectively. This study assessed the psychometric properties of objective parameters that define and quantify the severity of the spastic catch in children with cerebral palsy (CP). A convenience sample of children with spastic CP (N = 46; age range: 4-16 years) underwent objective spasticity…

Non-invasive optical measurement of cerebral metabolism and hemodynamics in infants.

PubMed

Lin, Pei-Yi; Roche-Labarbe, Nadege; Dehaes, Mathieu; Carp, Stefan; Fenoglio, Angela; Barbieri, Beniamino; Hagan, Katherine; Grant, P Ellen; Franceschini, Maria Angela

2013-03-14

Perinatal brain injury remains a significant cause of infant mortality and morbidity, but there is not yet an effective bedside tool that can accurately screen for brain injury, monitor injury evolution, or assess response to therapy. The energy used by neurons is derived largely from tissue oxidative metabolism, and neural hyperactivity and cell death are reflected by corresponding changes in cerebral oxygen metabolism (CMRO₂). Thus, measures of CMRO₂ are reflective of neuronal viability and provide critical diagnostic information, making CMRO₂ an ideal target for bedside measurement of brain health. Brain-imaging techniques such as positron emission tomography (PET) and single-photon emission computed tomography (SPECT) yield measures of cerebral glucose and oxygen metabolism, but these techniques require the administration of radionucleotides, so they are used in only the most acute cases. Continuous-wave near-infrared spectroscopy (CWNIRS) provides non-invasive and non-ionizing radiation measures of hemoglobin oxygen saturation (SO₂) as a surrogate for cerebral oxygen consumption. However, SO₂ is less than ideal as a surrogate for cerebral oxygen metabolism as it is influenced by both oxygen delivery and consumption. Furthermore, measurements of SO₂ are not sensitive enough to detect brain injury hours after the insult, because oxygen consumption and delivery reach equilibrium after acute transients. We investigated the possibility of using more sophisticated NIRS optical methods to quantify cerebral oxygen metabolism at the bedside in healthy and brain-injured newborns. More specifically, we combined the frequency-domain NIRS (FDNIRS) measure of SO2 with the diffuse correlation spectroscopy (DCS) measure of blood flow index (CBFi) to yield an index of CMRO₂ (CMRO₂i). With the combined FDNIRS/DCS system we are able to quantify cerebral metabolism and hemodynamics. This represents an improvement over CWNIRS for detecting brain health, brain

Opiates and cerebral functional activity in rats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Trusk, T.C.

1986-01-01

Cerebral activity was measured using the free-fatty acid (1-/sup 14/C) octanoate as a fast functional tracer in conscious, unrestrained rats 5 minutes after intravenous injection of heroin, cocaine or saline vehicle. Regional changes of octanoate labeling density in the autoradiograms relative to saline-injected animals were used to determine the functional activity effects of each drug. Heroin and cocaine each produced a distinctive pattern of activity increases and suppression throughout the rat brain. Similar regional changes induced by both drugs were found in limbic brain regions implicated in drug reinforcement. Labeled octanoate autoradiography was used to measure the cerebral functional responsemore » to a tone that had previously been paired to heroin injections. Rats were trained in groups of three consisting of one heroin self-administration animal, and two animals receiving yoked infusion of heroin or saline. A tone was paired with each infusion during training. Behavioral experiments in similarly trained rats demonstrated that these training conditions impart secondary reinforcing properties to the tone in animals previously self-administering heroin, while the tone remains behaviorally neutral in yoked-infusion rats. Cerebral functional activity was measured during presentation of the tone without drug infusion. Octanoate labeling density changed in fifteen brain areas in response to the tone previously paired to heroin without response contingency. Labeling density was significantly modified in sixteen regions as a result of previously pairing the tone to response-contingent heroin infusions.« less

A Computational Model of the Fetal Circulation to Quantify Blood Redistribution in Intrauterine Growth Restriction

PubMed Central

Garcia-Canadilla, Patricia; Rudenick, Paula A.; Crispi, Fatima; Cruz-Lemini, Monica; Palau, Georgina; Camara, Oscar; Gratacos, Eduard; Bijens, Bart H.

2014-01-01

Intrauterine growth restriction (IUGR) due to placental insufficiency is associated with blood flow redistribution in order to maintain delivery of oxygenated blood to the brain. Given that, in the fetus the aortic isthmus (AoI) is a key arterial connection between the cerebral and placental circulations, quantifying AoI blood flow has been proposed to assess this brain sparing effect in clinical practice. While numerous clinical studies have studied this parameter, fundamental understanding of its determinant factors and its quantitative relation with other aspects of haemodynamic remodeling has been limited. Computational models of the cardiovascular circulation have been proposed for exactly this purpose since they allow both for studying the contributions from isolated parameters as well as estimating properties that cannot be directly assessed from clinical measurements. Therefore, a computational model of the fetal circulation was developed, including the key elements related to fetal blood redistribution and using measured cardiac outflow profiles to allow personalization. The model was first calibrated using patient-specific Doppler data from a healthy fetus. Next, in order to understand the contributions of the main parameters determining blood redistribution, AoI and middle cerebral artery (MCA) flow changes were studied by variation of cerebral and peripheral-placental resistances. Finally, to study how this affects an individual fetus, the model was fitted to three IUGR cases with different degrees of severity. In conclusion, the proposed computational model provides a good approximation to assess blood flow changes in the fetal circulation. The results support that while MCA flow is mainly determined by a fall in brain resistance, the AoI is influenced by a balance between increased peripheral-placental and decreased cerebral resistances. Personalizing the model allows for quantifying the balance between cerebral and peripheral-placental remodeling

[Regional cerebral blood flow changes in Parkinson's disease: correlation with disease duration].

PubMed

Kapitán, M; Ferrando, R; Diéguez, E; de Medina, O; Aljanati, R; Ventura, R; Amorin, I; Salinas, D; Langhain, M; Gioia, A; Cardoso, A; Lago, G; Buzó, R

2009-01-01

Changes in regional cerebral blood flow (rCBF) have been reported in idiopathic Parkinson's disease (PD). Nonetheless, their typical pattern still remains controversial regarding some features, such as basal ganglia involvement and the main cortical regions affected. Functional neuroimaging makes it possible to identify the brain dysfunctions of the neural circuits underlying the disease. Voxel-based analysis methods make it possible to increase the reliability of the results. To assess the rCBF changes in patients with PD and their relation with disease duration. Thirty PD adult patients without dementia underwent evaluation with (99m)Tc-ECD SPECT. SPM5 was used for statistical comparison with 25 normal controls of similar ages. The disease course duration in years was added as a covariate. Additionally, patients with a 6-year evolution or less and those with more than 6 years were compared separately with normal controls. Significant hypoperfusion was detected in bilateral premotor and posterior parietal cortex and increase of perfusion was present in the cerebellum. These changes correlated with the years of evolution of the illness. Patients with longer evolution also presented thalamic, subthalamic and basal ganglia hypoperfusion. We describe rCBF changes in PD in neural circuits related with control of movements. These changes are more manifest in patients with a longer duration of the disease.

Regional cerebral blood flow changes in female to male gender identity disorder.

PubMed

Nawata, Hideyuki; Ogomori, Koji; Tanaka, Mariko; Nishimura, Ryoji; Urashima, Hajime; Yano, Rika; Takano, Koichi; Kuwabara, Yasuo

2010-04-01

Despite a range of research on gender identity disorder (GID), at present there is no scientific consensus on whether the etiology of GID is mental or physical. In particular recent advances in the technology of neuroimaging research have led to an increased understanding of the biological basis of various mental disorders. GID also should be evaluated from this perspective. The aim of the present study was therefore to do the first trial to examine the regional cerebral blood flow (rCBF) in GID. Persons considered biologically male fulfilling the GID criteria are termed male to female (MTF) and, conversely, persons considered biological female are termed female to male (FTM). We compared 11 FTM subjects and nine age- and handedness-matched female control subjects. None of the subjects was regularly taking medication and none had any kind of physical or psychiatric comorbidity. To evaluate rCBF in GID subjects and control subjects, statistical parametric mapping analysis of (99m)Tc-ethyl-cysteinate dimer single-photon emission computed tomography was used. GID subjects had a significant decrease in rCBF in the left anterior cingulate cortex (ACC) and a significant increase in the right insula compared to control subjects. The ACC and insula are regions that have been noted as being related to human sexual behavior and consciousness. From these findings, useful insights into the biological basis of GID were suggested.

Abnormal regional cerebral blood flow in childhood autism.

PubMed

Ohnishi, T; Matsuda, H; Hashimoto, T; Kunihiro, T; Nishikawa, M; Uema, T; Sasaki, M

2000-09-01

Neuroimaging studies of autism have shown abnormalities in the limbic system and cerebellar circuits and additional sites. These findings are not, however, specific or consistent enough to build up a coherent theory of the origin and nature of the brain abnormality in autistic patients. Twenty-three children with infantile autism and 26 non-autistic controls matched for IQ and age were examined using brain-perfusion single photon emission computed tomography with technetium-99m ethyl cysteinate dimer. In autistic subjects, we assessed the relationship between regional cerebral blood flow (rCBF) and symptom profiles. Images were anatomically normalized, and voxel-by-voxel analyses were performed. Decreases in rCBF in autistic patients compared with the control group were identified in the bilateral insula, superior temporal gyri and left prefrontal cortices. Analysis of the correlations between syndrome scores and rCBF revealed that each syndrome was associated with a specific pattern of perfusion in the limbic system and the medial prefrontal cortex. The results confirmed the associations of (i) impairments in communication and social interaction that are thought to be related to deficits in the theory of mind (ToM) with altered perfusion in the medial prefrontal cortex and anterior cingulate gyrus, and (ii) the obsessive desire for sameness with altered perfusion in the right medial temporal lobe. The perfusion abnormalities seem to be related to the cognitive dysfunction observed in autism, such as deficits in ToM, abnormal responses to sensory stimuli, and the obsessive desire for sameness. The perfusion patterns suggest possible locations of abnormalities of brain function underlying abnormal behaviour patterns in autistic individuals.

Non-invasive Assessment of Cerebral Blood Flow and Oxygen Metabolism in Neonates during Hypothermic Cardiopulmonary Bypass: Feasibility and Clinical Implications

PubMed Central

Ferradal, Silvina L.; Yuki, Koichi; Vyas, Rutvi; Ha, Christopher G.; Yi, Francesca; Stopp, Christian; Wypij, David; Cheng, Henry H.; Newburger, Jane W.; Kaza, Aditya K.; Franceschini, Maria A.; Kussman, Barry D.; Grant, P. Ellen

2017-01-01

The neonatal brain is extremely vulnerable to injury during periods of hypoxia and/or ischemia. Risk of brain injury is increased during neonatal cardiac surgery, where pre-existing hemodynamic instability and metabolic abnormalities are combined with long periods of low cerebral blood flow and/or circulatory arrest. Our understanding of events associated with cerebral hypoxia-ischemia during cardiopulmonary bypass (CPB) remains limited, largely due to inadequate tools to quantify cerebral oxygen delivery and consumption non-invasively and in real-time. This pilot study aims to evaluate cerebral blood flow (CBF) and oxygen metabolism (CMRO2) intraoperatively in neonates by combining two novel non-invasive optical techniques: frequency-domain near-infrared spectroscopy (FD-NIRS) and diffuse correlation spectroscopy (DCS). CBF and CMRO2 were quantified before, during and after deep hypothermic cardiopulmonary bypass (CPB) in nine neonates. Our results show significantly decreased CBF and CMRO2 during hypothermic CPB. More interestingly, a change of coupling between both variables is observed during deep hypothermic CPB in all subjects. Our results are consistent with previous studies using invasive techniques, supporting the concept of FD-NIRS/DCS as a promising technology to monitor cerebral physiology in neonates providing the potential for individual optimization of surgical management. PMID:28276534

Non-invasive Assessment of Cerebral Blood Flow and Oxygen Metabolism in Neonates during Hypothermic Cardiopulmonary Bypass: Feasibility and Clinical Implications.

PubMed

Ferradal, Silvina L; Yuki, Koichi; Vyas, Rutvi; Ha, Christopher G; Yi, Francesca; Stopp, Christian; Wypij, David; Cheng, Henry H; Newburger, Jane W; Kaza, Aditya K; Franceschini, Maria A; Kussman, Barry D; Grant, P Ellen

2017-03-09

The neonatal brain is extremely vulnerable to injury during periods of hypoxia and/or ischemia. Risk of brain injury is increased during neonatal cardiac surgery, where pre-existing hemodynamic instability and metabolic abnormalities are combined with long periods of low cerebral blood flow and/or circulatory arrest. Our understanding of events associated with cerebral hypoxia-ischemia during cardiopulmonary bypass (CPB) remains limited, largely due to inadequate tools to quantify cerebral oxygen delivery and consumption non-invasively and in real-time. This pilot study aims to evaluate cerebral blood flow (CBF) and oxygen metabolism (CMRO 2 ) intraoperatively in neonates by combining two novel non-invasive optical techniques: frequency-domain near-infrared spectroscopy (FD-NIRS) and diffuse correlation spectroscopy (DCS). CBF and CMRO 2 were quantified before, during and after deep hypothermic cardiopulmonary bypass (CPB) in nine neonates. Our results show significantly decreased CBF and CMRO 2 during hypothermic CPB. More interestingly, a change of coupling between both variables is observed during deep hypothermic CPB in all subjects. Our results are consistent with previous studies using invasive techniques, supporting the concept of FD-NIRS/DCS as a promising technology to monitor cerebral physiology in neonates providing the potential for individual optimization of surgical management.

A feasibility study of cerebral oximetry during in-hospital mechanical and manual cardiopulmonary resuscitation*.

PubMed

Parnia, Sam; Nasir, Asad; Ahn, Anna; Malik, Hanan; Yang, Jie; Zhu, Jiawen; Dorazi, Francis; Richman, Paul

2014-04-01

A major hurdle limiting the ability to improve the quality of resuscitation has been the lack of a noninvasive real-time detection system capable of monitoring the quality of cerebral and other organ perfusion, as well as oxygen delivery during cardiopulmonary resuscitation. Here, we report on a novel system of cerebral perfusion targeted resuscitation. An observational study evaluating the role of cerebral oximetry (Equanox; Nonin, Plymouth, MI, and Invos; Covidien, Mansfield, MA) as a real-time marker of cerebral perfusion and oxygen delivery together with the impact of an automated mechanical chest compression system (Life Stat; Michigan Instruments, Grand Rapids, MI) on oxygen delivery and return of spontaneous circulation following in-hospital cardiac arrest. Tertiary medical center. In-hospital cardiac arrest patients (n = 34). Cerebral oximetry provided real-time information regarding the quality of perfusion and oxygen delivery. The use of automated mechanical chest compression device (n = 12) was associated with higher regional cerebral oxygen saturation compared with manual chest compression device (n = 22) (53.1% ± 23.4% vs 24% ± 25%, p = 0.002). There was a significant difference in mean regional cerebral oxygen saturation (median % ± interquartile range) in patients who achieved return of spontaneous circulation (n = 15) compared with those without return of spontaneous circulation (n = 19) (47.4% ± 21.4% vs 23% ± 18.42%, p < 0.001). After controlling for patients achieving return of spontaneous circulation or not, significantly higher mean regional cerebral oxygen saturation levels during cardiopulmonary resuscitation were observed in patients who were resuscitated using automated mechanical chest compression device (p < 0.001). The integration of cerebral oximetry into cardiac arrest resuscitation provides a novel noninvasive method to determine the quality of cerebral perfusion and oxygen delivery to the brain. The use of automated mechanical

Sex-dependent alterations in resting-state cerebral blood flow, amplitude of low-frequency fluctuations and their coupling relationship in schizophrenia.

PubMed

Ma, Xiaomei; Wang, Di; Zhou, Yujing; Zhuo, Chuanjun; Qin, Wen; Zhu, Jiajia; Yu, Chunshui

2016-04-01

We aimed to investigate sex-dependent alterations in resting-state relative cerebral blood flow, amplitude of low-frequency fluctuations and relative cerebral blood flow-amplitude of low-frequency fluctuations coupling in patients with schizophrenia. Resting-state functional magnetic resonance imaging and three-dimensional pseudo-continuous arterial spin labeling imaging were performed to obtain resting-state amplitude of low-frequency fluctuations and relative cerebral blood flow in 95 schizophrenia patients and 99 healthy controls. Sex differences in relative cerebral blood flow and amplitude of low-frequency fluctuations were compared in both groups. Diagnostic group differences in relative cerebral blood flow, amplitude of low-frequency fluctuations and relative cerebral blood flow-amplitude of low-frequency fluctuations coupling were compared in male and female subjects, respectively. In both healthy controls and schizophrenia patients, the males had higher relative cerebral blood flow in anterior brain regions and lower relative cerebral blood flow in posterior brain regions than did the females. Compared with multiple regions exhibiting sex differences in relative cerebral blood flow, only the left middle frontal gyrus had a significant sex difference in amplitude of low-frequency fluctuations. In the females, schizophrenia patients exhibited increased relative cerebral blood flow and amplitude of low-frequency fluctuations in the basal ganglia, thalamus and hippocampus and reduced relative cerebral blood flow and amplitude of low-frequency fluctuations in the frontal, parietal and occipital regions compared with those of healthy controls. However, there were fewer brain regions with diagnostic group differences in the males than in the females. Brain regions with diagnostic group differences in relative cerebral blood flow and amplitude of low-frequency fluctuations only partially overlapped. Only the female patients exhibited increased relative cerebral

Perisylvian sulcal morphology and cerebral asymmetry patterns in adults who stutter.

PubMed

Cykowski, Matthew D; Kochunov, Peter V; Ingham, Roger J; Ingham, Janis C; Mangin, Jean-François; Rivière, Denis; Lancaster, Jack L; Fox, Peter T

2008-03-01

Previous investigations of cerebral anatomy in persistent developmental stutterers have reported bilateral anomalies in the perisylvian region and atypical patterns of cerebral asymmetry. In this study, perisylvian sulcal patterns were analyzed to compare subjects with persistent developmental stuttering (PDS) and an age-, hand-, and gender-matched control group. This analysis was accomplished using software designed for 3-dimensional sulcal identification and extraction. Patterns of cerebral asymmetry were also investigated with standard planimetric measurements. PDS subjects showed a small but significant increase in both the number of sulci connecting with the second segment of the right Sylvian fissure and in the number of suprasylvian gyral banks (of sulci) along this segment. No differences were seen in the left perisylvian region for either sulcal number or gyral bank number. Measurements of asymmetry revealed typical patterns of cerebral asymmetry in both groups with no significant differences in frontal and occipital width asymmetry, frontal and occipital pole asymmetry, or planum temporale and Sylvian fissure asymmetries. The subtle difference in cortical folding of the right perisylvian region observed in PDS subjects may correlate with functional imaging studies that have reported increased right-hemisphere activity during stuttered speech.

Spatial transcriptomic survey of human embryonic cerebral cortex by single-cell RNA-seq analysis.

PubMed

Fan, Xiaoying; Dong, Ji; Zhong, Suijuan; Wei, Yuan; Wu, Qian; Yan, Liying; Yong, Jun; Sun, Le; Wang, Xiaoye; Zhao, Yangyu; Wang, Wei; Yan, Jie; Wang, Xiaoqun; Qiao, Jie; Tang, Fuchou

2018-06-04

The cellular complexity of human brain development has been intensively investigated, although a regional characterization of the entire human cerebral cortex based on single-cell transcriptome analysis has not been reported. Here, we performed RNA-seq on over 4,000 individual cells from 22 brain regions of human mid-gestation embryos. We identified 29 cell sub-clusters, which showed different proportions in each region and the pons showed especially high percentage of astrocytes. Embryonic neurons were not as diverse as adult neurons, although they possessed important features of their destinies in adults. Neuron development was unsynchronized in the cerebral cortex, as dorsal regions appeared to be more mature than ventral regions at this stage. Region-specific genes were comprehensively identified in each neuronal sub-cluster, and a large proportion of these genes were neural disease related. Our results present a systematic landscape of the regionalized gene expression and neuron maturation of the human cerebral cortex.

Altered regional and circuit resting-state activity in patients with occult spastic diplegic cerebral palsy.

PubMed

Mu, Xuetao; Wang, Zhiqun; Nie, Binbin; Duan, Shaofeng; Ma, Qiaozhi; Dai, Guanghui; Wu, Chunnan; Dong, Yuru; Shan, Baoci; Ma, Lin

2017-10-07

Very few studies have been made to investigate functional activity changes in occult spastic diplegic cerebral palsy (SDCP). The purpose of this study was to analyze whole-brain resting state regional brain activity and functional connectivity (FC) changes in patients with SDCP. We examined 12 occult SDCP and 14 healthy control subjects using resting-state functional magnetic resonance imaging. The data were analyzed using Resting-State fMRI Data Analysis Toolkit (REST) software. The regional homogeneity (ReHo), amplitude of low-frequency fluctuations (ALFF), and whole brain FC of the motor cortex and thalamus were analyzed and compared between the occult SDCP and control groups. Compared with the control group, the occult SDCP group showed decreased ReHo regions, including the bilateral frontal, parietal, and temporal lobes, the cerebellum, right cingulate gyrus, and right lenticular nucleus, whereas an increased ReHo value was observed in the left precuneus, calcarine, fusiform gyrus, and right precuneus. Compared with the control group, no significant differences in ALFF were noted in the occult SDCP group. With the motor cortex as the region of interest, the occult SDCP group showed decreased connectivity regions in the bilateral fusiform and lingual gyrus, but increased connectivity regions in the contralateral precentral and postcentral gyrus, supplementary motor area, and the ipsilateral postcentral gyrus. With the thalamus being regarded as the region of interest, the occult SDCP group showed decreased connectivity regions in the bilateral basal ganglia, cingulate, and prefrontal cortex, but increased connectivity regions in the bilateral precentral gyrus, the contralateral cerebellum, and inferior temporal gyrus. Resting-state regional brain activities and FC changes in the patients with occult SDCP exhibited a special distribution pattern, which is consistent with the pathology of the disease. Copyright © 2017. Published by Elsevier B.V.

Quantifying the cerebral metabolic rate of oxygen by combining diffuse correlation spectroscopy and time-resolved near-infrared spectroscopy.

PubMed

Verdecchia, Kyle; Diop, Mamadou; Lee, Ting-Yim; St Lawrence, Keith

2013-02-01

Preterm infants are highly susceptible to ischemic brain injury; consequently, continuous bedside monitoring to detect ischemia before irreversible damage occurs would improve patient outcome. In addition to monitoring cerebral blood flow (CBF), assessing the cerebral metabolic rate of oxygen (CMRO2) would be beneficial considering that metabolic thresholds can be used to evaluate tissue viability. The purpose of this study was to demonstrate that changes in absolute CMRO2 could be measured by combining diffuse correlation spectroscopy (DCS) with time-resolved near-infrared spectroscopy (TR-NIRS). Absolute CBF was determined using bolus-tracking TR-NIRS to calibrate the DCS measurements. Cerebral venous blood oxygenation (SvO2) was determined by multiwavelength TR-NIRS measurements, the accuracy of which was assessed by directly measuring the oxygenation of sagittal sinus blood. In eight newborn piglets, CMRO2 was manipulated by varying the anesthetics and by injecting sodium cyanide. No significant differences were found between the two sets of SvO2 measurements obtained by TR-NIRS or sagittal sinus blood samples and the corresponding CMRO2 measurements. Bland-Altman analysis showed a mean CMRO2 difference of 0.0268 ± 0.8340 mLO2/100 g/min between the two techniques over a range from 0.3 to 4 mL O2/100 g/min.

Brain regions associated with cognitive impairment in patients with Parkinson disease: quantitative analysis of cerebral blood flow using 123I iodoamphetamine SPECT.

PubMed

Hattori, Naoya; Yabe, Ichiro; Hirata, Kenji; Shiga, Tohru; Sakushima, Ken; Tsuji-Akimoto, Sachiko; Sasaki, Hidenao; Tamaki, Nagara

2013-05-01

Cognitive impairment is a representative neuropsychiatric presentation that accompanies Parkinson disease (PD). The purpose of this study was to localize the cerebral regions associated with cognitive impairment in patients with PD using quantitative SPECT. Thirty-two patients with PD (mean [SD] age, 75 [8] years; 25 women; Hoehn-Yahr scores from 2 to 5) underwent quantitative brain SPECT using 123I iodoamphetamine. Parametric images of regional cerebral blood flow (rCBF) were spatially normalized to the standard brain atlas. First, voxel-by-voxel comparison between patients with PD with versus without cognitive impairment was performed to visualize overall trend of regional differences. Next, the individual quantitative rCBF values were extracted in representative cortical regions using a standard region-of-interest template to compare the quantitative rCBF values. Patients with cognitive impairment showed trends of lower rCBF in the left frontal and temporal cortices as well as in the bilateral medial frontal and anterior cingulate cortices in the voxel-by-voxel analyses. Region-of-interest-based analysis demonstrated significantly lower rCBF in the bilateral anterior cingulate cortices (right, 25.8 [5.5] vs 28.9 [5.7] mL per 100 g/min, P < 0.05; left, 25.8 [5.8] vs 29.1 [5.7] mL per 100 g/min, P < 0.05) associated with cognitive impairment. Patients with cognitive impairment showed lower rCBF in the left frontal and temporal cortices as well as in the bilateral medial frontal and anterior cingulate cortices. The results suggested dysexecutive function as an underlining mechanism of cognitive impairment in patients with PD.

Arterial blood gas management in retrograde cerebral perfusion: the importance of carbon dioxide.

PubMed

Ueno, K; Takamoto, S; Miyairi, T; Morota, T; Shibata, K; Murakami, A; Kotsuka, Y

2001-11-01

Many interventional physiological assessments for retrograde cerebral perfusion (RCP) have been explored. However, the appropriate arterial gas management of carbon dioxide (CO2) remains controversial. The aim of this study is to determine whether alpha-stat or pH-stat could be used for effective brain protection under RCP in terms of cortical cerebral blood flow (CBF), cerebral metabolic rate for oxygen (CMRO2), and distribution of regional cerebral blood flow. Fifteen anesthetized dogs (25.1+/-1.1 kg) on cardiopulmonary bypass (CPB) were cooled to 18 degrees C under alpha-stat management and had RCP for 90 min under: (1), alpha-stat; (2), pH-stat; or (3), deep hypothermic (18 degrees C) antegrade CPB (antegrade). RCP flow was regulated for a sagittal sinus pressure of around 25 mmHg. CBF was monitored by a laser tissue flowmeter. Serial analyses of blood gas were made. The regional cerebral blood flow was measured with colored microspheres before discontinuation of RCP. CBF and CMRO2 were evaluated as the percentage of the baseline level (%CBF, %CMRO2). The oxygen content of arterial inflow and oxygen extraction was not significantly different between the RCP groups. The %CBF and %CMRO2 were significantly higher for pH-stat RCP than for alpha-stat RCP. The regional cerebral blood flow, measured with colored microspheres, tended to be higher for pH-stat RCP than for alpha-stat RCP, at every site in the brain. Irrespective of CO2 management, regional differences were not significant among any site in the brain. CO2 management is crucial for brain protection under deep hypothermic RCP. This study revealed that pH-stat was considered to be better than alpha-stat in terms of CBF and oxygen metabolism in the brain. The regional blood flow distribution was considered to be unchanged irrespective of CO2 management.

[Research on brain white matter network in cerebral palsy infant].

PubMed

Li, Jun; Yang, Cheng; Wang, Yuanjun; Nie, Shengdong

2017-10-01

Present study used diffusion tensor image and tractography to construct brain white matter networks of 15 cerebral palsy infants and 30 healthy infants that matched for age and gender. After white matter network analysis, we found that both cerebral palsy and healthy infants had a small-world topology in white matter network, but cerebral palsy infants exhibited abnormal topological organization: increased shortest path length but decreased normalize clustering coefficient, global efficiency and local efficiency. Furthermore, we also found that white matter network hub regions were located in the left cuneus, precuneus, and left posterior cingulate gyrus. However, some abnormal nodes existed in the frontal, temporal, occipital and parietal lobes of cerebral palsy infants. These results indicated that the white matter networks for cerebral palsy infants were disrupted, which was consistent with previous studies about the abnormal brain white matter areas. This work could help us further study the pathogenesis of cerebral palsy infants.

Cerebral blood flow asymmetries in headache-free migraineurs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Levine, S.R.; Welch, K.M.; Ewing, J.R.

1987-11-01

Regional cerebral blood flow (rCBF) asymmetries were studied in controls and patients with common and classic/complicated migraine using /sup 133/Xe inhalation with 8 homologously situated external collimators over each cerebral hemisphere. Migraine patients as a group more frequently had posterior rCBF asymmetries than controls (p less than 0.03). Although there were no differences in the number of anterior rCBF asymmetries, migraine patients had 2 or more asymmetric probe pairs more often than controls (p less than 0.02). The posterior rCBF asymmetries, consistent with the site of activation of many migraine attacks, may be related to more labile control of themore » cerebral circulation.« less

Cerebral Perfusion Changes in Post-Concussion Syndrome: A Prospective Controlled Cohort Study

PubMed Central

Marcil, Lorenzo D.; Dewey, Deborah; Carlson, Helen L.; MacMaster, Frank P.; Brooks, Brian L.; Lebel, R. Marc

2017-01-01

Abstract The biology of post-concussive symptoms is unclear. Symptoms are often increased during activities, and have been linked to decreased cerebrovascular reactivity and perfusion. The aim of this study was to examine cerebral blood flow (CBF) in children with different clinical recovery patterns following mild traumatic brain injury (mTBI). This was a prospective controlled cohort study of children with mTBI (ages 8 to 18 years) who were symptomatic with post-concussive symptoms at one month post-injury (symptomatic, n = 27) and children who had recovered quickly (asymptomatic, n = 24). Pseudo continuous arterial spin labeling magnetic resonance imaging (MRI) was used to quantify CBF. The mTBI groups were imaged at 40 days post-injury. Global and regional CBF were compared with healthy controls of similar age and sex but without a history of mTBI (n = 21). Seventy-two participants (mean age: 14.1 years) underwent neuroimaging. Significant differences in CBF were found: global CBF was higher in the symptomatic group and lower in the asymptomatic group compared with controls, (F(2,69) 9.734; p < 0.001). Post-injury symptom score could be predicted by pre-injury symptoms and CBF in presence of mTBI (adjusted R2 = 0.424; p < 0.001). Altered patterns of cerebral perfusion are seen following mTBI and are associated with the recovery trajectory. Symptomatic children have higher CBF. Children who “recovered” quickly, have decreased CBF suggesting that clinical recovery precedes the cerebral recovery. Further longitudinal studies are required to determine if these perfusion patterns continue to change over time. PMID:27554429

Quantifying understorey vegetation in the US Lake States: a proposed framework to inform regional forest carbon stocks

USGS Publications Warehouse

Russell, Matthew B.; D'Amato, Anthony W.; Schulz, Bethany K.; Woodall, Christopher W.; Domke, Grant M.; Bradford, John B.

2014-01-01

The contribution of understorey vegetation (UVEG) to forest ecosystem biomass and carbon (C) across diverse forest types has, to date, eluded quantification at regional and national scales. Efforts to quantify UVEG C have been limited to field-intensive studies or broad-scale modelling approaches lacking field measurements. Although large-scale inventories of UVEG C are not common, species- and community-level inventories of vegetation structure are available and may prove useful in quantifying UVEG C stocks. This analysis developed a general framework for estimating UVEG C stocks by employing per cent cover estimates of UVEG from a region-wide forest inventory coupled with an estimate of maximum UVEG C across the US Lake States (i.e. Michigan, Minnesota and Wisconsin). Estimates of UVEG C stocks from this approach reasonably align with expected C stocks in the study region, ranging from 0.86 ± 0.06 Mg ha-1 in red pine-dominated to 1.59 ± 0.06 Mg ha-1 for aspen/birch-dominated forest types. Although the data employed here were originally collected to assess broad-scale forest structure and diversity, this study proposes a framework for using UVEG inventories as a foundation for estimating C stocks in an often overlooked, yet important ecosystem C pool.

Quantifying understorey vegetation in the US Lake States: a proposed framework to inform regional forest carbon stocks

Treesearch

Matthew B. Russell; Anthony W. D' Amato; Bethany K. Schulz; Christopher W. Woodall; Grant M. Domke; John B. Bradford

2014-01-01

The contribution of understorey vegetation (UVEG) to forest ecosystem biomass and carbon (C) across diverse forest types has, to date, eluded quantification at regional and national scales. Efforts to quantify UVEG C have been limited to field-intensive studies or broad-scalemodelling approaches lacking fieldmeasurements. Although large-scale inventories of UVEG C are...

Neuroimaging findings in children with retinopathy-confirmed cerebral malaria.

PubMed

Potchen, Michael J; Birbeck, Gretchen L; Demarco, J Kevin; Kampondeni, Sam D; Beare, Nicholas; Molyneux, Malcolm E; Taylor, Terrie E

2010-04-01

To describe brain CT findings in retinopathy-confirmed, paediatric cerebral malaria. In this outcomes study of paediatric cerebral malaria, a subset of children with protracted coma during initial presentation was scanned acutely. Survivors experiencing adverse neurological outcomes also underwent a head CT. All children had ophthalmological examination to confirm the presence of the retinopathy specific for cerebral malaria. Independent interpretation of CT images was provided by two neuroradiologists. Acute brain CT findings in three children included diffuse oedema with obstructive hydrocephalus (2), acute cerebral infarctions in multiple large vessel distributions with secondary oedema and herniation (1), and oedema of thalamic grey matter (1). One child who was reportedly normal prior to admission had parenchymal atrophy suggestive of pre-existing CNS injury. Among 56 survivors (9-84 months old), 15 had adverse neurologic outcomes-11/15 had a follow-up head CT, 3/15 died and 1/15 refused CT. Follow-up head CTs obtained 7-18 months after the acute infection revealed focal and multifocal lobar atrophy correlating to regions affected by focal seizures during the acute infection (5/11). Other findings were communicating hydrocephalus (2/11), vermian atrophy (1/11) and normal studies (3/11). The identification of pre-existing imaging abnormalities in acute cerebral malaria suggests that population-based studies are required to establish the rate and nature of incidental imaging abnormalities in Malawi. Children with focal seizures during acute cerebral malaria developed focal cortical atrophy in these regions at follow-up. Longitudinal studies are needed to further elucidate mechanisms of CNS injury and death in this common fatal disease. Copyright (c) 2010 Elsevier Ireland Ltd. All rights reserved.

Quantifying and Projecting Relative Sea-Level Rise in The Deltaic Regions

NASA Astrophysics Data System (ADS)

Shum, C. K.; Chung-Yen, K.; Calmant, S.; Yang, T. Y.; Guo, Q.; Jia, Y.; Ballu, V.; Guo, J.; Karptychev, M.; Krien, Y.; Kusche, J.; Tseng, K. H.; Wan, J.; Uebbing, B.

2017-12-01

Half of the world's population lives within 200 km of coastlines. Accelerated sea-level rise, compounded by effects of population growth, severe land subsidence due to fluvial sediment compaction/load, and anthropogenic oil and natural gas and ground water extraction, tectonic motion, and the increasing threat of more intense and more frequent cyclone-driven storm surges, have exacerbated the vulnerability of many of world's deltaic regions, including the Bangladesh and the Mississippi River Deltas. At present, understanding and quantifying the natural and anthropogenic processes governing these solid Earth vertical motion processes remain elusive to enable addressing coastal vulnerability due to current and future projection of relative sea-level rise for deltaic regions at the regional scales. Bangladesh, a low-lying and one of the most densely populated countries in the world located at the Bay of Bengal, is prone to transboundary monsoonal flooding, and is believed to be aggravated by more frequent and intensified cyclones resulting from anthropogenic climate change. The Mississippi River Deltaic region has been severely subsiding due primarily to fluvial sediment compaction and load during the last 10 centuries, oil/gas and groundwater extractions, and commercial developments, making it vulnerable to sea-level rise hazards. Here we present results of global geocentric sea-level rise, 1950-2016, separating vertical land motion at global tide gauge datum, by integrating tide gauge and radar altimeter records in a novel sea-level reconstruction scheme, focusing on the Mississippi River and the Bangladesh Deltas. We then integrate the resulting sea level estimates with historic imageries, GPS and InSAR data, as well as sediment isostatic and load model predicted present-day land subsidence, to constrain the 3D land motion to study the impacts of various scenarios of future relative sea level projections on the Bangladesh Delta to the end of the 21st Century and

Quantifying the cerebral metabolic rate of oxygen by combining diffuse correlation spectroscopy and time-resolved near-infrared spectroscopy

NASA Astrophysics Data System (ADS)

Verdecchia, Kyle; Diop, Mamadou; Lee, Ting-Yim; St. Lawrence, Keith

2013-02-01

Preterm infants are highly susceptible to ischemic brain injury; consequently, continuous bedside monitoring to detect ischemia before irreversible damage occurs would improve patient outcome. In addition to monitoring cerebral blood flow (CBF), assessing the cerebral metabolic rate of oxygen (CMRO2) would be beneficial considering that metabolic thresholds can be used to evaluate tissue viability. The purpose of this study was to demonstrate that changes in absolute CMRO2 could be measured by combining diffuse correlation spectroscopy (DCS) with time-resolved near-infrared spectroscopy (TR-NIRS). Absolute CBF was determined using bolus-tracking TR-NIRS to calibrate the DCS measurements. Cerebral venous blood oxygenation (SvO2) was determined by multiwavelength TR-NIRS measurements, the accuracy of which was assessed by directly measuring the oxygenation of sagittal sinus blood. In eight newborn piglets, CMRO2 was manipulated by varying the anesthetics and by injecting sodium cyanide. No significant differences were found between the two sets of SvO2 measurements obtained by TR-NIRS or sagittal sinus blood samples and the corresponding CMRO2 measurements. Bland-Altman analysis showed a mean CMRO2 difference of 0.0268±0.8340 mL O2/100 g/min between the two techniques over a range from 0.3 to 4 mL O2/100 g/min.

Cerebral aneurysm

MedlinePlus Videos and Cool Tools

The tissue of the brain is supplied by a network of cerebral arteries. If the wall of a cerebral artery becomes weakened, a portion of the wall may balloon out forming an aneurysm. A cerebral aneurysm may enlarge until it bursts, sending blood ...

An evaluation of bilateral monitoring of cerebral oxygen saturation during pediatric cardiac surgery.

PubMed

Kussman, Barry D; Wypij, David; DiNardo, James A; Newburger, Jane; Jonas, Richard A; Bartlett, Jodi; McGrath, Ellen; Laussen, Peter C

2005-11-01

Cerebral oximetry is a technique that enables monitoring of regional cerebral oxygenation during cardiac surgery. In this study, we evaluated differences in bi-hemispheric measurement of cerebral oxygen saturation using near-infrared spectroscopy in 62 infants undergoing biventricular repair without aortic arch reconstruction. Left and right regional cerebral oxygen saturation index (rSO2i) were recorded continuously after the induction of anesthesia, and data were analyzed at 12 time points. Baseline rSO2i measurements were left 65 +/- 13 and right 66 +/- 13 (P = 0.17). Mean left and right rSO2i measurements were similar (< or =2 percentage points/absolute scale units) before, during, and after cardiopulmonary bypass, irrespective of the use of deep hypothermic circulatory arrest. Further longitudinal neurological outcome studies are required to determine whether uni- or bi-hemispheric monitoring is required in this patient population.

The role of blood flow distribution in the regulation of cerebral oxygen availability in fetal growth restriction.

PubMed

Luria, Oded; Bar, Jacob; Kovo, Michal; Malinger, Gustavo; Golan, Abraham; Barnea, Ofer

2012-04-01

Fetal growth restriction (FGR) elicits hemodynamic compensatory mechanisms in the fetal circulation. These mechanisms are complex and their effect on the cerebral oxygen availability is not fully understood. To quantify the contribution of each compensatory mechanism to the fetal cerebral oxygen availability, a mathematical model of the fetal circulation was developed. The model was based on cardiac-output distribution in the fetal circulation. The compensatory mechanisms of FGR were simulated and their effects on cerebral oxygen availability were analyzed. The mathematical analysis included the effects of cerebral vasodilation, placental resistance to blood flow, degree of blood shunting by the ductus venosus and the effect of maternal-originated placental insufficiency. The model indicated a unimodal dependency between placental blood flow and cerebral oxygen availability. Optimal cerebral oxygen availability was achieved when the placental blood flow was mildly reduced compared to the normal flow. This optimal ratio was found to increase as the hypoxic state of FGR worsens. The model indicated that cerebral oxygen availability is increasingly dependent on the cardiac output distribution as the fetus gains weight. Copyright © 2011 IPEM. Published by Elsevier Ltd. All rights reserved.

Cerebral sex dimorphism and sexual orientation.

PubMed

Manzouri, Amirhossein; Savic, Ivanka

2018-03-01

The neurobiology of sexual orientation is frequently discussed in terms of cerebral sex dimorphism (defining both functional and structural sex differences). Yet, the information about possible cerebral differences between sex-matched homo and heterosexual persons is limited, particularly among women. In this multimodal MRI study, we addressed these issues by investigating possible cerebral differences between homo and heterosexual persons, and by asking whether there is any sex difference in this aspect. Measurements of cortical thickness (Cth), subcortical volumes, and functional and structural resting-state connections among 40 heterosexual males (HeM) and 40 heterosexual females (HeF) were compared with those of 30 homosexual males (HoM) and 30 homosexual females (HoF). Congruent with previous reports, sex differences were detected in heterosexual controls with regard to fractional anisotropy (FA), Cth, and several subcortical volumes. Homosexual groups did not display any sex differences in FA values. Furthermore, their functional connectivity was significantly less pronounced in the mesial prefrontal and precuneus regions. In these two particular regions, HoM also displayed thicker cerebral cortex than other groups, whereas HoF did not differ from HeF. In addition, in HoM the parietal Cth showed "sex-reversed" values, not observed in HoF. Homosexual orientation seems associated with a less pronounced sexual differentiation of white matter tracts and a less pronounced functional connectivity of the self-referential networks compared to heterosexual orientation. Analyses of Cth suggest that male and female homosexuality are not simple analogues of each other and that differences from heterosexual controls are more pronounced in HoM. © 2017 Wiley Periodicals, Inc.

Dynamic change in cerebral microcirculation and focal cerebral metabolism in experimental subarachnoid hemorrhage in rabbits.

PubMed

Song, Jin-Ning; Chen, Hu; Zhang, Ming; Zhao, Yong-Lin; Ma, Xu-Dong

2013-03-01

Regional cerebral blood flow (rCBF) in the cerebral metabolism and energy metabolism measurements can be used to assess blood flow of brain cells and to detect cell activity. Changes of rCBF in the cerebral microcirculation and energy metabolism were determined in an experimental model of subarachnoid hemorrhage (SAH) model in 56 large-eared Japanese rabbits about 12 to 16-month old. Laser Doppler flowmetry was used to detect the blood supply to brain cells. Internal carotid artery and vein blood samples were used for duplicate blood gas analysis to assess the energy metabolism of brain cells. Cerebral blood flow (CBF) was detected by single photon emission computed tomography (SPECT) perfusion imaging using Tc-99m ethyl cysteinate dimer (Tc-99m ECD) as an imaging reagent. The percentage of injected dose per gram of brain tissue was calculated and analyzed. There were positive correlations between the percentage of radionuclide injected per gram of brain tissue and rCBF supply and cerebral metabolic rate for oxygen (P < 0.05). However, there was a negative correlation between radioactivity counts per unit volume detected on the SPECT rheoencephalogram and lactic acid concentration in the homolateral internal carotid artery and vein. In summary, this study found abnormal CBF in metabolism and utilization of brain cells after SAH, and also found that deterioration of energy metabolism of brain cells played a significant role in the development of SAH. There are matched reductions in CBF and metabolism. Thus, SPECT imaging could be used as a noninvasive method to detect CBF.

Motor Control of the Lower Extremity Musculature in Children with Cerebral Palsy

ERIC Educational Resources Information Center

Arpin, David J.; Stuberg, Wayne; Stergiou, Nicholas; Kurz, Max J.

2013-01-01

The aim of this investigation was to quantify the differences in torque steadiness and variability of the muscular control in children with cerebral palsy (CP) and typically developing (TD) children. Fifteen children with CP (age = 14.2 [plus or minus] 0.7 years) that had a Gross Motor Function Classification System (GMFCS) score of I-III and 15…

Human cerebral organoids recapitulate gene expression programs of fetal neocortex development

PubMed Central

Camp, J. Gray; Badsha, Farhath; Florio, Marta; Kanton, Sabina; Gerber, Tobias; Wilsch-Bräuninger, Michaela; Lewitus, Eric; Sykes, Alex; Hevers, Wulf; Lancaster, Madeline; Knoblich, Juergen A.; Lachmann, Robert; Pääbo, Svante; Huttner, Wieland B.; Treutlein, Barbara

2015-01-01

Cerebral organoids—3D cultures of human cerebral tissue derived from pluripotent stem cells—have emerged as models of human cortical development. However, the extent to which in vitro organoid systems recapitulate neural progenitor cell proliferation and neuronal differentiation programs observed in vivo remains unclear. Here we use single-cell RNA sequencing (scRNA-seq) to dissect and compare cell composition and progenitor-to-neuron lineage relationships in human cerebral organoids and fetal neocortex. Covariation network analysis using the fetal neocortex data reveals known and previously unidentified interactions among genes central to neural progenitor proliferation and neuronal differentiation. In the organoid, we detect diverse progenitors and differentiated cell types of neuronal and mesenchymal lineages and identify cells that derived from regions resembling the fetal neocortex. We find that these organoid cortical cells use gene expression programs remarkably similar to those of the fetal tissue to organize into cerebral cortex-like regions. Our comparison of in vivo and in vitro cortical single-cell transcriptomes illuminates the genetic features underlying human cortical development that can be studied in organoid cultures. PMID:26644564

Investigating cerebral oedema using poroelasticity.

PubMed

Vardakis, John C; Chou, Dean; Tully, Brett J; Hung, Chang C; Lee, Tsong H; Tsui, Po-Hsiang; Ventikos, Yiannis

2016-01-01

Cerebral oedema can be classified as the tangible swelling produced by expansion of the interstitial fluid volume. Hydrocephalus can be succinctly described as the abnormal accumulation of cerebrospinal fluid (CSF) within the brain which ultimately leads to oedema within specific sites of parenchymal tissue. Using hydrocephalus as a test bed, one is able to account for the necessary mechanisms involved in the interaction between oedema formation and cerebral fluid production, transport and drainage. The current state of knowledge about integrative cerebral dynamics and transport phenomena indicates that poroelastic theory may provide a suitable framework to better understand various diseases. In this work, Multiple-Network Poroelastic Theory (MPET) is used to develop a novel spatio-temporal model of fluid regulation and tissue displacement within the various scales of the cerebral environment. The model is applied through two formats, a one-dimensional finite difference - Computational Fluid Dynamics (CFD) coupling framework, as well as a two-dimensional Finite Element Method (FEM) formulation. These are used to investigate the role of endoscopic fourth ventriculostomy in alleviating oedema formation due to fourth ventricle outlet obstruction (1D coupled model) in addition to observing the capability of the FEM template in capturing important characteristics allied to oedema formation, like for instance in the periventricular region (2D model). Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Differential effects of gaseous versus injectable anesthetics on changes in regional cerebral blood flow and metabolism induced by l-DOPA in a rat model of Parkinson's disease.

PubMed

Bimpisidis, Zisis; Öberg, Carl M; Maslava, Natallia; Cenci, M Angela; Lundblad, Cornelia

2017-06-01

Preclinical imaging of brain activity requires the use of anesthesia. In this study, we have compared the effects of two widely used anesthetics, inhaled isoflurane and ketamine/xylazine cocktail, on cerebral blood flow and metabolism in a rat model of Parkinson's disease and l-DOPA-induced dyskinesia. Specific tracers were used to estimate regional cerebral blood flow (rCBF - [ 14 C]-iodoantipyrine) and regional cerebral metabolic rate (rCMR - [ 14 C]-2-deoxyglucose) with a highly sensitive autoradiographic method. The two types of anesthetics had quite distinct effects on l-DOPA-induced changes in rCBF and rCMR. Isoflurane did not affect either the absolute rCBF values or the increases in rCBF in the basal ganglia after l-DOPA administration. On the contrary, rats anesthetized with ketamine/xylazine showed lower absolute rCBF values, and the rCBF increases induced by l-DOPA were masked. We developed a novel improved model to calculate rCMR, and found lower metabolic activities in rats anesthetized with isoflurane compared to animals anesthetized with ketamine/xylazine. Both anesthetics prevented changes in rCMR upon l-DOPA administration. Pharmacological challenges in isoflurane-anesthetized rats indicated that drugs mimicking the actions of ketamine/xylazine on adrenergic or glutamate receptors reproduced distinct effects of the injectable anesthetics on rCBF and rCMR. Our results highlight the importance of anesthesia in studies of cerebral flow and metabolism, and provide novel insights into mechanisms mediating abnormal neurovascular responses to l-DOPA in Parkinson's disease. Copyright © 2017 Elsevier Inc. All rights reserved.

Voxel-based statistical analysis of cerebral glucose metabolism in patients with permanent vegetative state after acquired brain injury.

PubMed

Kim, Yong Wook; Kim, Hyoung Seop; An, Young-Sil; Im, Sang Hee

2010-10-01

Permanent vegetative state is defined as the impaired level of consciousness longer than 12 months after traumatic causes and 3 months after non-traumatic causes of brain injury. Although many studies assessed the cerebral metabolism in patients with acute and persistent vegetative state after brain injury, few studies investigated the cerebral metabolism in patients with permanent vegetative state. In this study, we performed the voxel-based analysis of cerebral glucose metabolism and investigated the relationship between regional cerebral glucose metabolism and the severity of impaired consciousness in patients with permanent vegetative state after acquired brain injury. We compared the regional cerebral glucose metabolism as demonstrated by F-18 fluorodeoxyglucose positron emission tomography from 12 patients with permanent vegetative state after acquired brain injury with those from 12 control subjects. Additionally, covariance analysis was performed to identify regions where decreased changes in regional cerebral glucose metabolism significantly correlated with a decrease of level of consciousness measured by JFK-coma recovery scale. Statistical analysis was performed using statistical parametric mapping. Compared with controls, patients with permanent vegetative state demonstrated decreased cerebral glucose metabolism in the left precuneus, both posterior cingulate cortices, the left superior parietal lobule (P(corrected) < 0.001), and increased cerebral glucose metabolism in the both cerebellum and the right supramarginal cortices (P(corrected) < 0.001). In the covariance analysis, a decrease in the level of consciousness was significantly correlated with decreased cerebral glucose metabolism in the both posterior cingulate cortices (P(uncorrected) < 0.005). Our findings suggest that the posteromedial parietal cortex, which are part of neural network for consciousness, may be relevant structure for pathophysiological mechanism in patients with permanent

Tanshinone IIA attenuates the cerebral ischemic injury-induced increase in levels of GFAP and of caspases-3 and -8.

PubMed

Zhou, L; Bondy, S C; Jian, L; Wen, P; Yang, F; Luo, H; Li, W; Zhou, Jun

2015-03-12

Tanshinone IIA (TSA) is a lipid soluble agent derived from the root of Salvia miltiorrhiza (Danshen). This plant is a traditional Chinese herb, which has been used widely in China especially for enhancing circulation. However mechanisms underlying its efficacy remain poorly understood. The present study was designed to illuminate events that may underlie the apparently neuroprotective effects of TSA following ischemic insult. Adult Sprague-Dawley rats were subjected to transient focal cerebral ischemia by use of a middle cerebral artery occlusion model. They were then randomly divided into a sham-operated control group, and cerebral ischemia/reperfusion groups receiving a two-hour occlusion. Further subsets of groups received the same durations of occlusion or were sham-operated but then received daily i.p. injections of high or low doses of TSA, for seven or 15days. Hematoxylin and eosin staining revealed lesions in the entorhinal cortex of both rats subject to ischemia and to a lesser extent to those receiving TSA after surgery. Levels of glial fibrillary acidic protein (GFAP), caspase-3 and caspase-8, were quantified by both immunohistochemistry and Western blotting. TSA treatment after middle cerebral artery occlusion, markedly reduced infarct size, and reduced the expression of caspase-3 and caspase-8. These changes were considered protective and were generally proportional to the dose of TSA used. These results suggest that TSA may effect neuroprotection by way of reduction of the extent of cell inflammation and death within affected regions. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

Monitoring the Relationship Between Changes in Cerebral Oxygenation and Electroencephalography Patterns During Cardiopulmonary Resuscitation: A Feasibility Study.

PubMed

Reagan, Elizabeth M; Nguyen, Robert T; Ravishankar, Shreyas T; Chabra, Vikram; Fuentes, Barbara; Spiegel, Rebecca; Parnia, Sam

2018-05-01

To date, no studies have examined real-time electroencephalography and cerebral oximetry monitoring during cardiopulmonary resuscitation as markers of the magnitude of global ischemia. We therefore sought to assess the feasibility of combining cerebral oximetry and electroencephalography in patients undergoing cardiopulmonary resuscitation and further to evaluate the electroencephalography patterns during cardiopulmonary resuscitation and their relationship with cerebral oxygenation as measured by cerebral oximetry. Extended case series of in-hospital and out-of-hospital cardiac arrest subjects. Tertiary Medical Center. Inclusion criteria: Convenience sample of 16 patients undergoing cardiopulmonary resuscitation during working hours between March 2014 and March 2015, greater than or equal to 18 years. A portable electroencephalography (Legacy; SedLine, Masimo, Irvine, CA) and cerebral oximetry (Equanox 7600; Nonin Medical, Plymouth, MN) system was used to measure cerebral resuscitation quality. Real-time regional cerebral oxygen saturation and electroencephalography readings were observed during cardiopulmonary resuscitation. The regional cerebral oxygen saturation values and electroencephalography patterns were not used to manage patients by clinical staff. In total, 428 electroencephalography images from 16 subjects were gathered; 40.7% (n = 174/428) were artifactual, therefore 59.3% (n = 254/428) were interpretable. All 16 subjects had interpretable images. Interpretable versus noninterpretable images were not related to a function of time or duration of cardiopulmonary resuscitation but to artifacts that were introduced to the raw data such as diaphoresis, muscle movement, or electrical interference. Interpretable data were able to be obtained immediately after application of the electrode strip. Seven distinct electroencephalography patterns were identified. Voltage suppression was commonest and seen during 78% of overall cardiopulmonary resuscitation time

Normal regional distribution of cerebral blood flow in dogs: comparison between (99m) Tc-ethylcysteinate dimer and (99m) Tc- hexamethylpropylene amine oxime single photon emission computed tomography.

PubMed

Adriaens, Antita; Polis, Ingeborgh; Waelbers, Tim; Vandermeulen, Eva; Dobbeleir, André; De Spiegeleer, Bart; Peremans, Kathelijne

2013-01-01

Functional imaging provides important insights into canine brain pathologies such as behavioral problems. Two (99m) Tc-labeled single photon emission computed tomography (SPECT) cerebral blood flow tracers-ethylcysteinate dimer (ECD) and hexamethylpropylene amine oxime (HMPAO)-are commonly used in human medicine and have been used previously in dogs but intrasubject comparison of both tracers in dogs is lacking. Therefore, this study investigated whether regional distribution differences between both tracers occur in dogs as is reported in humans. Eight beagles underwent two SPECT examinations first with (99m) Tc-ECD and followed by (99m) Tc-HMPAO. SPECT scanning was performed with a triple head gamma camera equipped with ultrahigh resolution parallel hole collimators. Images were reconstructed using filtered backprojection with a Butterworth filter. Emission data were fitted to a template permitting semiquantification using predefined regions or volumes of interest (VOIs). For each VOI, perfusion indices were calculated by normalizing the regional counts per voxel to total brain counts per voxel. The obtained perfusion indices for each region for both tracers were compared with a paired Student's T-test. Significant (P < 0.05) regional differences were seen in the subcortical region and the cerebellum. Both tracers can be used to visualize regional cerebral blood flow in dogs, however, due to the observed regional differences, they are not entirely interchangeable. © 2013 Veterinary Radiology & Ultrasound.

Cerebral Palsy (For Parents)

MedlinePlus

... Staying Safe Videos for Educators Search English Español Cerebral Palsy KidsHealth / For Parents / Cerebral Palsy What's in this ... Ahead Print en español Parálisis cerebral What Is Cerebral Palsy? Cerebral palsy (CP) is a disorder that affects ...

White Matter Hyperintensity Associations with Cerebral Blood Flow in Elderly Subjects Stratified by Cerebrovascular Risk.

PubMed

Bahrani, Ahmed A; Powell, David K; Yu, Guoquiang; Johnson, Eleanor S; Jicha, Gregory A; Smith, Charles D

2017-04-01

This study aims to add clarity to the relationship between deep and periventricular brain white matter hyperintensities (WMHs), cerebral blood flow (CBF), and cerebrovascular risk in older persons. Deep white matter hyperintensity (dWMH) and periventricular white matter hyperintensity (pWMH) and regional gray matter (GM) and white matter (WM) blood flow from arterial spin labeling were quantified from magnetic resonance imaging scans of 26 cognitively normal elderly subjects stratified by cerebrovascular disease (CVD) risk. Fluid-attenuated inversion recovery images were acquired using a high-resolution 3-dimensional (3-D) sequence that reduced partial volume effects seen with slice-based techniques. dWMHs but not pWMHs were increased in patients at high risk of CVD; pWMHs but not dWMHs were associated with decreased regional cortical (GM) blood flow. We also found that blood flow in WM is decreased in regions of both pWMH and dWMH, with a greater degree of decrease in pWMH areas. WMHs are usefully divided into dWMH and pWMH regions because they demonstrate differential effects. 3-D regional WMH volume is a potentially valuable marker for CVD based on associations with cortical CBF and WM CBF. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Increased resting cerebral blood flow in adult Fabry disease: MRI arterial spin labeling study.

PubMed

Phyu, Po; Merwick, Aine; Davagnanam, Indran; Bolsover, Fay; Jichi, Fatima; Wheeler-Kingshott, Claudia; Golay, Xavier; Hughes, Deralynn; Cipolotti, Lisa; Murphy, Elaine; Lachmann, Robin H; Werring, David John

2018-04-17

To assess resting cerebral blood flow (CBF) in the whole-brain and cerebral white matter (WM) and gray matter (GM) of adults with Fabry disease (FD), using arterial spin labeling (ASL) MRI, and to investigate CBF correlations with WM hyperintensity (WMH) volume and the circulating biomarker lyso-Gb3. This cross-sectional, case-control study included 25 patients with genetically confirmed FD and 18 age-matched healthy controls. We quantified resting CBF using Quantitative Signal Targeting With Alternating Radiofrequency Labeling of Arterial Regions (QUASAR) ASL MRI. We measured WMH volume using semiautomated software. We measured CBF in regions of interest in whole-brain, WM, and deep GM, and assessed correlations with WMH volume and plasma lyso-Gb3. The mean age (% male) for FD and healthy controls was 42.2 years (44%) and 37.1 years (50%). Mean whole-brain CBF was 27.56 mL/100 mL/min (95% confidence interval [CI] 23.78-31.34) for FD vs 22.39 mL/100 mL/min (95% CI 20.08-24.70) for healthy controls, p = 0.03. In WM, CBF was higher in FD (22.42 mL/100 mL/min [95% CI 17.72-27.12] vs 16.25 mL/100 mL/min [95% CI 14.03-18.48], p = 0.05). In deep GM, CBF was similar between groups (40.41 mL/100 mL/min [95% CI 36.85-43.97] for FD vs 37.46 mL/100 mL/min [95% CI 32.57-42.35], p = 0.38). In patients with FD with WMH (n = 20), whole-brain CBF correlated with WMH volume ( r = 0.59, p = 0.006), not with plasma lyso-Gb3. In FD, resting CBF is increased in WM but not deep GM. In FD, CBF correlates with WMH, suggesting that cerebral perfusion changes might contribute to, or result from, WM injury. © 2018 American Academy of Neurology.

Effect of ethanol on cerebral blood flow (CBF) and metabolism (CMRO2) in conscious sheep

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krasney, J.A.; Zubkov, B.; Iwamoto, J.

1991-03-11

A moderate dose of ethanol severely depresses CBF and CMRO2 in the awake sheep fetus. However, the effects of ethanol on CBF and CMRO2 in the adult are unclear. The same dose of ethanol was infused for 2 hr in 5 ewes instrumented with aortic, left ventricular and sagittal sinus catheters. Ethanol caused ataxia accompanied by early modest and variable increases of total and regional CBF and CMRO2, followed by later modest and variable decreases of total and regional CBF (cerebellum) and CMRO2. Ethanol caused a cerebral transcapillary fluid shift as indicated by significant increases of the arterial-cerebral venous differencesmore » for hematocrit and hemoglobin. Brain wet-dry ratios increased by 10% above control levels. However, cerebral venous pressures were unchanged. The authors conclude that the adult cerebral response to ethanol differs quantitatively from that of the fetus. The functional significance of the cerebral fluid shift is unclear.« less

Dynamic cerebral autoregulation measured with coherent hemodynamics spectroscopy (CHS)

NASA Astrophysics Data System (ADS)

Kainerstorfer, Jana M.; Sassaroli, Angelo; Tgavalekos, Kristen T.; Fantini, Sergio

2015-03-01

Coherent Hemodynamics Spectroscopy (CHS) is a novel technique for non-invasive measurements of local microcirculation quantities such as the capillary blood transit times and dynamic autoregulation. The basis of CHS is to measure, for instance with near-infrared spectroscopy (NIRS), peripheral coherent hemodynamic changes that are induced by controlled perturbations in the systemic mean arterial pressure (MAP). In this study, the MAP perturbation was induced by the fast release of two pneumatic cuffs placed around the subject's thighs after they were kept inflated (at 200 mmHg) for two minutes. The resulting transient changes in cerebral oxy- (O) and deoxy- (D) hemoglobin concentrations measured with NIRS on the prefrontal cortex are then described by a novel hemodynamic model, from which quantifiable parameters such as the capillary blood transit time and a cutoff frequency for cerebral autoregulation are obtained. We present results on eleven healthy volunteers in a protocol involving measurements during normal breathing and during hyperventilation, which is known to cause a hypocapnia-induced increase in cerebral autoregulation. The measured capillary transit time was unaffected by hyperventilation (normal breathing: 1.1±0.1 s; hyperventilation: 1.1±0.1 s), whereas the cutoff frequency of autoregulation, which increases for higher autoregulation efficiency, was indeed found to be significantly greater during hyperventilation (normal breathing: 0.017±0.002 Hz; hyperventilation: 0.034±0.005 Hz). These results provide a validation of local cerebral autoregulation measurements with the new technique of CHS.

Decreased cerebellar-cerebral connectivity contributes to complex task performance

PubMed Central

Knops, André

2016-01-01

The cerebellum's role in nonmotor processes is now well accepted, but cerebellar interaction with cerebral targets is not well understood. Complex cognitive tasks activate cerebellar, parietal, and frontal regions, but the effective connectivity between these regions has never been tested. To this end, we used psycho-physiological interactions (PPI) analysis to test connectivity changes of cerebellar and parietal seed regions in complex (2-digit by 1-digit multiplication, e.g., 12 × 3) vs. simple (1-digit by 1-digit multiplication, e.g., 4 × 3) task conditions (“complex − simple”). For cerebellar seed regions (lobule VI, hemisphere and vermis), we found significantly decreased cerebellar-parietal, cerebellar-cingulate, and cerebellar-frontal connectivity in complex multiplication. For parietal seed regions (PFcm, PFop, PFm) we found significantly increased parietal-parietal and parietal-frontal connectivity in complex multiplication. These results suggest that decreased cerebellar-cerebral connectivity contributes to complex task performance. Interestingly, BOLD activity contrasts revealed partially overlapping parietal areas of increased BOLD activity but decreased cerebellar-parietal PPI connectivity. PMID:27334957

Multiple Spontaneous Cerebral Microbleeds and Leukoencephalopathy in PSEN1-Associated Familial Alzheimer's Disease: Mirror of Cerebral Amyloid Angiopathy?

PubMed

Floris, Gianluca; Di Stefano, Francesca; Cherchi, Maria Valeria; Costa, Gianna; Marrosu, Francesco; Marrosu, Maria Giovanna

2015-01-01

Cerebral microbleeds (CMB) might reflect specific underlying vascular pathologies like cerebral amyloid angiopathy (CAA). In the present study we report the gradient-echo MRI pattern of two siblings with P284S PSEN1 mutation. T2* gradient-echo images of the two subjects demonstrated multiple microbleeds in lobar regions. The role and causes of CMB in sporadic Alzheimer's disease (AD) patients have not been clearly established and useful contributions could derive from familial AD studies. Furthermore, since CAA is a potential risk factor for developing adverse events in AD immunization trials, the identification in vivo of CAA through non-invasive MRI methods could be useful to monitoring side effects.

Types of traumatic brain injury and regional cerebral blood flow assessed by 99mTc-HMPAO SPECT.

PubMed

Yamakami, I; Yamaura, A; Isobe, K

1993-01-01

To investigate the relationship between focal and diffuse traumatic brain injury (TBI) and regional cerebral blood flow (rCBF), rCBF changes in the first 24 hours post-trauma were studied in 12 severe head trauma patients using single photon emission computed tomography (SPECT) with 99mtechnetium-hexamethyl propyleneamine oxime. Patients were classified as focal or diffuse TBI based on x-ray computed tomographic (X-CT) findings and neurological signs. In six patients with focal damage, SPECT demonstrated 1) perfusion defect (focal severe ischemia) in the brain region larger than the brain contusion by X-CT, 2) hypoperfusion (focal CBF reduction) in the brain region without abnormality by X-CT, and 3) localized hyperperfusion (focal CBF increase) in the surgically decompressed brain after decompressive craniectomy. Focal damage may be associated with a heterogeneous CBF change by causing various focal CBF derangements. In six patients with diffuse damage, SPECT revealed hypoperfusion in only one patient. Diffuse damage may be associated with a homogeneous CBF change by rarely causing focal CBF derangements. The type of TBI, focal or diffuse, determines the type of CBF change, heterogeneous or homogeneous, in the acute severe head trauma patient.

Cerebral blood flow autoregulation is impaired in schizophrenia: A pilot study.

PubMed

Ku, Hsiao-Lun; Wang, Jiunn-Kae; Lee, Hsin-Chien; Lane, Timothy Joseph; Liu, I-Chao; Chen, Yung-Chan; Lee, Yao-Tung; Lin, I-Cheng; Lin, Chia-Pei; Hu, Chaur-Jong; Chi, Nai-Fang

2017-10-01

Patients with schizophrenia have a higher risk of cardiovascular diseases and higher mortality from them than does the general population; however, the underlying mechanism remains unclear. Impaired cerebral autoregulation is associated with cerebrovascular diseases and their mortality. Increased or decreased cerebral blood flow in different brain regions has been reported in patients with schizophrenia, which implies impaired cerebral autoregulation. This study investigated the cerebral autoregulation in 21 patients with schizophrenia and 23 age- and sex-matched healthy controls. None of the participants had a history of cardiovascular diseases, hypertension, or diabetes. All participants underwent 10-min blood pressure and cerebral blood flow recording through finger plethysmography and Doppler ultrasonography, respectively. Cerebral autoregulation was assessed by analyzing two autoregulation indices: the mean blood pressure and cerebral blood flow correlation coefficient (Mx), and the phase shift between the waveforms of blood pressure and cerebral blood flow determined using transfer function analysis. Compared with the controls, the patients had a significantly higher Mx (0.257 vs. 0.399, p=0.036) and lower phase shift (44.3° vs. 38.7° in the 0.07-0.20Hz frequency band, p=0.019), which indicated impaired maintenance of constant cerebral blood flow and a delayed cerebrovascular autoregulatory response. Impaired cerebral autoregulation may be caused by schizophrenia and may not be an artifact of coexisting medical conditions. The mechanism underlying impaired cerebral autoregulation in schizophrenia and its probable role in the development of cerebrovascular diseases require further investigation. Copyright © 2017 Elsevier B.V. All rights reserved.

Regionally clustered ABCC8 polymorphisms in a prospective cohort predict cerebral oedema and outcome in severe traumatic brain injury.

PubMed

Jha, Ruchira Menka; Koleck, Theresa A; Puccio, Ava M; Okonkwo, David O; Park, Seo-Young; Zusman, Benjamin E; Clark, Robert S B; Shutter, Lori A; Wallisch, Jessica S; Empey, Philip E; Kochanek, Patrick M; Conley, Yvette P

2018-04-19

ABCC8 encodes sulfonylurea receptor 1, a key regulatory protein of cerebral oedema in many neurological disorders including traumatic brain injury (TBI). Sulfonylurea-receptor-1 inhibition has been promising in ameliorating cerebral oedema in clinical trials. We evaluated whether ABCC8 tag single-nucleotide polymorphisms predicted oedema and outcome in TBI. DNA was extracted from 485 prospectively enrolled patients with severe TBI. 410 were analysed after quality control. ABCC8 tag single-nucleotide polymorphisms (SNPs) were identified (Hapmap, r 2 >0.8, minor-allele frequency >0.20) and sequenced (iPlex-Gold, MassArray). Outcomes included radiographic oedema, intracranial pressure (ICP) and 3-month Glasgow Outcome Scale (GOS) score. Proxy SNPs, spatial modelling, amino acid topology and functional predictions were determined using established software programs. Wild-type rs7105832 and rs2237982 alleles and genotypes were associated with lower average ICP (β=-2.91, p=0.001; β=-2.28, p=0.003) and decreased radiographic oedema (OR 0.42, p=0.012; OR 0.52, p=0.017). Wild-type rs2237982 also increased favourable 3-month GOS (OR 2.45, p=0.006); this was partially mediated by oedema (p=0.03). Different polymorphisms predicted 3-month outcome: variant rs11024286 increased (OR 1.84, p=0.006) and wild-type rs4148622 decreased (OR 0.40, p=0.01) the odds of favourable outcome. Significant tag and concordant proxy SNPs regionally span introns/exons 2-15 of the 39-exon gene. This study identifies four ABCC8 tag SNPs associated with cerebral oedema and/or outcome in TBI, tagging a region including 33 polymorphisms. In polymorphisms predictive of oedema, variant alleles/genotypes confer increased risk. Different variant polymorphisms were associated with favourable outcome, potentially suggesting distinct mechanisms. Significant polymorphisms spatially clustered flanking exons encoding the sulfonylurea receptor site and transmembrane domain 0/loop 0 (juxtaposing the channel pore

[Imaging Observation of Scalp Acupuncture on Brain Gray Matter Injury in Stroke Patients with Cerebral Infarction].

PubMed

Lang, Yi; Cui, Fang-yuan; Li, Kuang-shi; Tan, Zhong-jian; Zou, Yi-huai

2016-03-01

To study features of brain gray matter injury in cerebral infarction patients and intervention of scalp acupuncture by using voxel-based morphology. A total of 16 cerebral infarction patients were recruited in this study, and assigned to the scalp acupuncture group and the control group, 8 in each group. Another 16 healthy volunteers were recruited as a normal group. All patients received scanning of T1 structure. Images were managed using VBM8 Software package. Difference of the gray matter structure was compared among the scalp acupuncture group, the control group, and the healthy volunteers. Compared with healthy volunteers, gray matter injury of cerebral infarction patients mainly occurred in 14 brain regions such as cingulate gyrus, precuneus, cuneus, anterior central gyrus, insular lobe, and so on. They were mainly distributed in affected side. Two weeks after treatment when compared with healthy volunteers, gray matter injury of cerebral infarction patients in the scalp acupuncture group still existed in 8 brain regions such as bilateral lingual gyrus, posterior cingulate gyrus, left cuneus, right precuneus, and so on. New gray matter injury occurred in lingual gyrus and posterior cingulate gyrus. Two weeks after treatment when compared with healthy volunteers, gray matter injury of cerebral infarction patients in the control group existed in 23 brain regions: bilateral anterior cingulum, caudate nucleus, cuneate lobe, insular lobe, inferior frontal gyrus, medial frontal gyrus, precuneus, paracentral lobule, superior temporal gyrus, middle temporal gyrus, lingual gyrus, right postcentral gyrus, posterior cingulate gyrus, precentral gyrus, middle frontal gyrus, and so on. New gray matter injury still existed in 9 cerebral regions such as lingual gyrus, posterior cingulate gyrus, postcentral gyrus, and so on. Brain gray matter structure is widely injured after cerebral infarction. Brain gray matter volume gradually decreased as time went by. Combined use of

Cerebral autoregulation during whole-body hypothermia and hyperthermia stimulus.

PubMed

Doering, T J; Aaslid, R; Steuernagel, B; Brix, J; Niederstadt, C; Breull, A; Schneider, B; Fischer, G C

1999-01-01

The purpose of the study contained herein was to investigate the effects of old traditional physiotherapeutic treatments on cerebral autoregulation. Treatment consisted of complete body immersion in cold or warm water baths. Fifteen volunteers were investigated by means of transcranial Doppler sonography and a servo-controlled noninvasive device for blood pressure measuring. One group of 8 volunteers (mean age, 27.2+/-3.5 yr; gender, 3 females/5 males) was subjected to cold baths of 22 degrees C for 20 min Another group of 7 volunteers (mean age, 52.1+/-8.5 yr; gender, 4 females/3 males) took hyperthermic baths at rising water temperatures from 36 degrees to 42 degrees C, increased by 1 degree C every 5 min. Each volunteer in both groups underwent autoregulation tests two to four times before, during, and after the thermic bath. Dynamic autoregulation was measured by the response of cerebral blood flow velocity to a transient decrease of the mean arterial blood pressure, induced by rapid deflation of thigh cuffs. The autoregulation index, i.e., a measure of the speed of change of cerebral autoregulation, was used to quantify the response. Further parameters were core temperature, blood pressure (mm Hg) and CO2et. During hypothermic baths, core temperature decreased by 0.3 degrees C (P = 0.001), measured between preliminary phase and the end of the bath; the autoregulation index decreased significantly (P < 0.05) from 5.3 before the bath to 4.25 during the bath. During hyperthermic baths, the autoregulation index increased from 6.0 to 7.5 and 8.9 (P < 0.001), with an increase of core temperature of 0.4 degrees C. The main cerebral autoregulation system is dependent on changes of core temperature, provoked by hypothermic or hyperthermic whole-body thermostimulus. Application of hyperthermic baths increased the autoregulation index, and hypothermic baths decreased the autoregulation index. Further studies are needed to prove the positive effects of thermo

Hypopituitarism in children with cerebral palsy.

PubMed

Uday, Suma; Shaw, Nick; Krone, Ruth; Kirk, Jeremy

2017-06-01

Poor growth and delayed puberty in children with cerebral palsy is frequently felt to be related to malnutrition. Although growth hormone deficiency is commonly described in these children, multiple pituitary hormone deficiency (MPHD) has not been previously reported. We present a series of four children with cerebral palsy who were born before 29 weeks gestation who were referred to the regional endocrinology service, three for delayed puberty and one for short stature, in whom investigations identified MPHD. All patients had a height well below -2 standard deviation score (2nd centile) at presentation and three who had MRI scans had an ectopic posterior pituitary gland. We therefore recommend that the possibility of MPHD should be considered in all children with cerebral palsy and poor growth or delayed puberty. Early diagnosis and treatment is essential to maximise growth and prevent associated morbidity and mortality. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Cerebral Palsy (For Teens)

MedlinePlus

... Staying Safe Videos for Educators Search English Español Cerebral Palsy KidsHealth / For Teens / Cerebral Palsy What's in this ... do just what everyone else does. What Is Cerebral Palsy? Cerebral palsy (CP) is a disorder of the ...

Cerebral blood flow changes during sodium-lactate-induced panic attacks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stewart, R.S.; Devous, M.D. Sr.; Rush, A.J.

1988-04-01

Dynamic single-photon emission computed axial tomography (CAT) with inhaled xenon-133 was used to measure regional cerebral blood flow in 10 drug-free patients with DSM-III-diagnosed panic disorder and in five normal control subjects. All subjects underwent regional cerebral blood flow studies while at rest or during normal saline infusion and during sodium lactate infusion. Six of the 10 patients and none of the control subjects experienced lactate-induced panic attacks. Lactate infusion markedly raised hemispheric blood flow levels in both control subjects and patients who did not panic. Patients who did panic experienced either a minimal increase or a decrease in hemisphericmore » blood flow.« less

Increased cerebral oxygen consumption in Eker rats and effects of N-methyl-D-aspartate blockade: Implications for autism.

PubMed

Weiss, Harvey R; Liu, Xia; Zhang, Qihang; Chi, Oak Z

2007-08-15

Because there is a strong correlation between tuberous sclerosis and autism, we used a tuberous sclerosis model (Eker rat) to test the hypothesis that these animals would have an altered regional cerebral O2 consumption that might be associated with autism. We also examined whether the altered cerebral O2 consumption was related to changes in the importance of N-methyl-D-aspartate (NMDA) receptors. Young (4 weeks) male control Long Evans (N = 14) and Eker (N = 14) rats (70-100 g) were divided into control and CGS-19755 (10 mg/kg, competitive NMDA antagonist)-treated animals. Cerebral regional blood flow (14C-iodoantipyrine) and O2 consumption (cryomicrospectrophotometry) were determined in isoflurane-anesthetized rats. NMDA receptor protein levels were determined by Western immunoblotting. We found significantly increased basal O2 consumption in the cortex (6.2 +/- 0.6 ml O2/min/100 g Eker vs. 4.7 +/- 0.4 Long Evans), hippocampus, cerebellum, and pons. Regional cerebral blood flow was also elevated in Eker rats at baseline, but cerebral O2 extraction was similar. CGS-19755 significantly lowered O2 consumption in the cortex (2.8 +/- 0.3), hippocampus, and pons of the Long Evans rats but had no effect on cortex (5.8 +/- 0.8) or other regions of the Eker rats. Cerebral blood flow followed a similar pattern. NMDA receptor protein levels (NR1 subunit) were similar between groups. In conclusion, Eker rats had significantly elevated cerebral O2 consumption and blood flow, but this was not related to NMDA receptor activation. In fact, the importance of NMDA receptors in the control of basal cerebral O2 consumption was reduced. This might have important implications in the treatment of autism. Copyright 2007 Wiley-Liss, Inc.

[Progress of researches on mechanism of acupuncture therapy underlying improvement of acute cerebral hemorrhage].

PubMed

Wang, Fan; Wang, Hai-qiao; Dong, Gui-rong

2011-04-01

In the present paper, the authors review the progress of researches on the mechanism of acupuncture therapy underlying improvement of acute cerebral hemorrhage from experimental studies and research methods. The effects of acupuncture intervention mainly involve (1) lessening inflammatory reactions, (2) reducing impairment of free radicals and excitatory amino acids on cerebral neurons, (3) balancing release of vascular bioactive substances to increase regional cerebral blood flow, and (4) promoting repair and regeneration of the neural tissue, etc. In regard to the research methods, many new biological techniques such as biological molecular approaches, neuro-cellular chemical methods, reverse transcription-polymerase chain reaction (RT-PCR) or quantitative real time-PCR, situ hybridization, western blotting, electron microscope, etc., have been extensively applied to researches on the underlying mechanism of acupuncture therapy for cerebral infarction. In addition, the authors also pointed out that in spite of achieving some bigger progresses in experimental studies, most of the results basically reflect static, isolated and regional changes rather than dynamic and whole body changes. For this reason, more vivo research techniques and noninvasive research methods are highly recommended to be used in the future research on the underlying mechanisms of acupuncture therapy for acute cerebral ischemia.

Convection-enhanced delivery of AAV2 in white matter--a novel method for gene delivery to cerebral cortex.

PubMed

Barua, N U; Woolley, M; Bienemann, A S; Johnson, D; Wyatt, M J; Irving, C; Lewis, O; Castrique, E; Gill, S S

2013-10-30

Convection-enhanced delivery (CED) is currently under investigation for delivering therapeutic agents to subcortical targets in the brain. Direct delivery of therapies to the cerebral cortex, however, remains a significant challenge. We describe a novel method of targeting adeno-associated viral vector (AAV) mediated gene therapies to specific cerebral cortical regions by performing high volume, high flow rate infusions into underlying white matter in a large animal (porcine) model. Infusion volumes of up to 700 μl at flow rates as high as 10 μl/min were successfully performed in white matter without adverse neurological sequelae. Co-infusion of AAV2/5-GFP with 0.2% Gadolinium in artificial CSF confirmed transgene expression in the deep layers of cerebral cortex overlying the infused areas of white matter. AAV-mediated gene therapies have been previously targeted to the cerebral cortex by performing intrathalamic CED and exploiting axonal transport. The novel method described in this study facilitates delivery of gene therapies to specific regions of the cerebral cortex without targeting deep brain structures. AAV-mediated gene therapies can be targeted to specific cortical regions by performing CED into underlying white matter. This technique could be applied to the treatment of neurological disorders characterised by cerebral cortical degeneration. Copyright © 2013 Elsevier B.V. All rights reserved.

Cerebral ischemia and neuroregeneration

PubMed Central

Lee, Reggie H. C.; Lee, Michelle H. H.; Wu, Celeste Y. C.; Couto e Silva, Alexandre; Possoit, Harlee E.; Hsieh, Tsung-Han; Minagar, Alireza; Lin, Hung Wen

2018-01-01

Cerebral ischemia is one of the leading causes of morbidity and mortality worldwide. Although stroke (a form of cerebral ischemia)-related costs are expected to reach 240.67 billion dollars by 2030, options for treatment against cerebral ischemia/stroke are limited. All therapies except anti-thrombolytics (i.e., tissue plasminogen activator) and hypothermia have failed to reduce neuronal injury, neurological deficits, and mortality rates following cerebral ischemia, which suggests that development of novel therapies against stroke/cerebral ischemia are urgently needed. Here, we discuss the possible mechanism(s) underlying cerebral ischemia-induced brain injury, as well as current and future novel therapies (i.e., growth factors, nicotinamide adenine dinucleotide, melatonin, resveratrol, protein kinase C isozymes, pifithrin, hypothermia, fatty acids, sympathoplegic drugs, and stem cells) as it relates to cerebral ischemia. PMID:29623912

Cerebral Blood Flow and Glucose Metabolism in Appetite-Related Brain Regions in Type 1 Diabetic Patients After Treatment With Insulin Detemir and NPH Insulin

PubMed Central

van Golen, Larissa W.; IJzerman, Richard G.; Huisman, Marc C.; Hensbergen, Jolanda F.; Hoogma, Roel P.; Drent, Madeleine L.; Lammertsma, Adriaan A.; Diamant, Michaela

2013-01-01

OBJECTIVE To test the hypothesis that insulin detemir, which is associated with less weight gain than other basal insulin formulations, exerts its weight-modulating effects by acting on brain regions involved in appetite regulation, as represented by altered cerebral blood flow (CBF) or cerebral glucose metabolism (CMRglu). RESEARCH DESIGN AND METHODS Twenty-eight male type 1 diabetic patients (age 36.9 ± 9.7 years, BMI 24.9 ± 2.7 kg/m2, A1C 7.5 ± 0.6%) successfully completed a randomized crossover study, consisting of two periods of 12-week treatment with either insulin detemir or NPH insulin, both in combination with prandial insulin aspart. After each treatment period, patients underwent positron emission tomography scans to measure regional CBF and CMRglu. RESULTS After 12 weeks, A1C, daily insulin doses, fasting insulin, and blood glucose levels were similar between treatments. Insulin detemir resulted in body weight loss, whereas NPH insulin induced weight gain (between-treatment difference 1.3 kg; P = 0.02). After treatment with insulin detemir relative to NPH insulin, CBF was higher in brain regions involved in appetite regulation, whereas no significant difference in CMRglu was observed. CONCLUSIONS Treatment with insulin detemir versus NPH insulin resulted in weight loss, paralleled by increased CBF in appetite-related brain regions in the resting state, in men with well-controlled type 1 diabetes. These findings lend support to the hypothesis that a differential effect on the brain may contribute to the consistently observed weight-sparing effect of insulin detemir. PMID:24130356

Cerebral oxygen metabolism in patients with early Parkinson's disease.

PubMed

Borghammer, Per; Cumming, Paul; Østergaard, Karen; Gjedde, Albert; Rodell, Anders; Bailey, Christopher J; Vafaee, Manoucher S

2012-02-15

Decreased activity of the mitochondrial electron transport chain (ETC) has been implicated in the pathogenesis of Parkinson's disease (PD). This model would most likely predict a decrease in the rate of cerebral oxygen consumption (CMRO(2)). To test this hypothesis, we compared CMRO(2) and cerebral blood flow (CBF) PET scans from PD patients and healthy controls. Nine early-stage PD patients and 15 healthy age-matched controls underwent PET scans for quantitative mapping of CMRO(2) and CBF. Between-group differences were evaluated for absolute data and intensity-normalized values. No group differences were detected in regional magnitudes of CMRO(2) or CBF. Upon normalization using the reference cluster method, significant relative CMRO(2) decreases were evident in widespread prefrontal, parieto-occipital, and lateral temporal regions. Sensory-motor and subcortical regions, brainstem, and the cerebellum were spared. A similar pattern was evident in normalized CBF data, as described previously. While the data did not reveal substantially altered absolute CMRO(2) in brain of PD patients, employing data-driven intensity normalization revealed widespread relative CMRO(2) decreases in cerebral cortex. The detected pattern was very similar to that reported in earlier CBF and CMRglc studies of PD, and in the CBF images from the same subjects. Thus, the present results are consistent with the occurrence of parallel declines in CMRO(2), CBF, and CMRglc in spatially contiguous cortical regions in early PD, and support the hypothesis that ETC dysfunction could be a primary pathogenic mechanism in early PD. Copyright © 2011 Elsevier B.V. All rights reserved.

Is Vasomotion in Cerebral Arteries Impaired in Alzheimer's Disease?

PubMed

Di Marco, Luigi Yuri; Farkas, Eszter; Martin, Chris; Venneri, Annalena; Frangi, Alejandro F

2015-01-01

A substantial body of evidence supports the hypothesis of a vascular component in the pathogenesis of Alzheimer's disease (AD). Cerebral hypoperfusion and blood-brain barrier dysfunction have been indicated as key elements of this pathway. Cerebral amyloid angiopathy (CAA) is a cerebrovascular disorder, frequent in AD, characterized by the accumulation of amyloid-β (Aβ) peptide in cerebral blood vessel walls. CAA is associated with loss of vascular integrity, resulting in impaired regulation of cerebral circulation, and increased susceptibility to cerebral ischemia, microhemorrhages, and white matter damage. Vasomotion- the spontaneous rhythmic modulation of arterial diameter, typically observed in arteries/arterioles in various vascular beds including the brain- is thought to participate in tissue perfusion and oxygen delivery regulation. Vasomotion is impaired in adverse conditions such as hypoperfusion and hypoxia. The perivascular and glymphatic pathways of Aβ clearance are thought to be driven by the systolic pulse. Vasomotion produces diameter changes of comparable amplitude, however at lower rates, and could contribute to these mechanisms of Aβ clearance. In spite of potential clinical interest, studies addressing cerebral vasomotion in the context of AD/CAA are limited. This study reviews the current literature on vasomotion, and hypothesizes potential paths implicating impaired cerebral vasomotion in AD/CAA. Aβ and oxidative stress cause vascular tone dysregulation through direct effects on vascular cells, and indirect effects mediated by impaired neurovascular coupling. Vascular tone dysregulation is further aggravated by cholinergic deficit and results in depressed cerebrovascular reactivity and (possibly) impaired vasomotion, aggravating regional hypoperfusion and promoting further Aβ and oxidative stress accumulation.

Supraorbital Postmortem Brain Sampling for Definitive Quantitative Confirmation of Cerebral Sequestration of Plasmodium falciparum Parasites

PubMed Central

Milner, Danny A.; Valim, Clarissa; Luo, Robert; Playforth, Krupa B.; Kamiza, Steve; Molyneux, Malcolm E.; Seydel, Karl B.; Taylor, Terrie E.

2012-01-01

Background The conventional clinical case definition of cerebral malaria (CM) is imprecise but specificity is improved by a definitive clinical feature such as retinopathy or confirming sequestration of parasites in a post-mortem examination of the brain. A full autopsy is often not possible, since it is costly and may encounter resistance of the deceased's family. Methods We have assessed the use of a cytological smear of brain tissue, obtained post-mortem by supraorbital sampling, for the purpose of quantifying cerebral sequestration in children with fatal malaria in Blantyre, Malawi. We have compared this method to histological quantification of parasites at autopsy. Results The number of parasites present on cytological smears correlated with the proportion of vessels parasitized as assessed by histology of fixed and stained brain tissue. Use of cytological results in addition to the standard clinical case definition increases the specificity of the clinical case definition alone from 48.3% to 100% with a minimal change in sensitivity. Conclusions Post-mortem supraorbital sampling of brain tissue improves the specificity of the diagnosis of fatal cerebral malaria and provides accurate quantitative estimates of cerebral sequestration. This tool can be of great value in clinical, pathogenetic, and epidemiological research studies on cerebral malaria. PMID:22291197

Cerebral blood flow response to hypoglycemia is altered in patients with type 1 diabetes and impaired awareness of hypoglycemia

PubMed Central

Becker, Kirsten M; Rooijackers, Hanne M; von Samson-Himmelstjerna, Federico C; Tack, Cees J; Heerschap, Arend; de Galan, Bastiaan E; van der Graaf, Marinette

2016-01-01

It is unclear whether cerebral blood flow responses to hypoglycemia are altered in people with type 1 diabetes and impaired awareness of hypoglycemia. The aim of this study was to investigate the effect of hypoglycemia on both global and regional cerebral blood flow in type 1 diabetes patients with impaired awareness of hypoglycemia, type 1 diabetes patients with normal awareness of hypoglycemia and healthy controls (n = 7 per group). The subjects underwent a hyperinsulinemic euglycemic–hypoglycemic glucose clamp in a 3 T MR system. Global and regional changes in cerebral blood flow were determined by arterial spin labeling magnetic resonance imaging, at the end of both glycemic phases. Hypoglycemia generated typical symptoms in patients with type 1 diabetes and normal awareness of hypoglycemia and healthy controls, but not in patients with impaired awareness of hypoglycemia. Conversely, hypoglycemia increased global cerebral blood flow in patients with impaired awareness of hypoglycemia, which was not observed in the other two groups. Regionally, hypoglycemia caused a redistribution of cerebral blood flow towards the thalamus of both patients with normal awareness of hypoglycemia and healthy controls, consistent with activation of brain regions associated with the autonomic response to hypoglycemia. No such redistribution was found in the patients with impaired awareness of hypoglycemia. An increase in global cerebral blood flow may enhance nutrient supply to the brain, hence suppressing symptomatic awareness of hypoglycemia. Altogether these results suggest that changes in cerebral blood flow during hypoglycemia contribute to impaired awareness of hypoglycemia. PMID:27389175

Is impaired cerebral vasoreactivity an early marker of cognitive decline in multiple sclerosis patients?

PubMed

Metzger, Aude; Le Bars, Emmanuelle; Deverdun, Jeremy; Molino, François; Maréchal, Bénédicte; Picot, Marie-Christine; Ayrignac, Xavier; Carra, Clarisse; Bauchet, Luc; Krainik, Alexandre; Labauge, Pierre; Menjot de Champfleur, Nicolas

2018-03-01

The link between cerebral vasoreactivity and cognitive status in multiple sclerosis remains unclear. The aim of the present study was to investigate a potential decrease of cerebral vasoreactivity in multiple sclerosis patients and correlate it with cognitive status. Thirty-three patients with multiple sclerosis (nine progressive and 24 remitting forms, median age: 39 years, 12 males) and 22 controls underwent MRI with a hypercapnic challenge to assess cerebral vasoreactivity and a neuropsychological assessment. Cerebral vasoreactivity, measured as the cerebral blood flow percent increase normalised by end-tidal carbon dioxide variation, was assessed globally and by regions of interest using the blood oxygen level-dependent technique. Non-parametric statistics tests were used to assess differences between groups, and associations were estimated using linear models. Cerebral vasoreactivity was lower in patients with cognitive impairment than in cognitively normal patients (p=0.004) and was associated with education level in patients (R 2 = 0.35; p = 0.047). There was no decrease in cerebral vasoreactivity between patients and controls. Cognitive impairment in multiple sclerosis may be mediated through decreased cerebral vasoreactivity. Cerebral vasoreactivity could therefore be considered as a marker of cognitive decline in multiple sclerosis. • Cerebral vasoreactivity does not differ between multiple sclerosis patients and controls. • Cerebral vasoreactivity measure is linked to cognitive impairment in multiple sclerosis. • Cerebral vasoreactivity is linked to level of education in multiple sclerosis.

Transcranial Doppler-based assessment of cerebral autoregulation in critically ill children during diabetic ketoacidosis treatment.

PubMed

Ma, Li; Roberts, Joan S; Pihoker, Catherine; Richards, Todd L; Shaw, Dennis W W; Marro, Ken I; Vavilala, Monica S

2014-10-01

Impaired cerebral autoregulation may be associated with poor outcome in diabetic ketoacidosis. We examined change in cerebral autoregulation during diabetic ketoacidosis treatment. Prospective observational cohort study. Tertiary care children's hospital. Children admitted to the ICU with diabetic ketoacidosis (venous pH < 7.3, glucose > 300 mg/dL, HCO3 < 15 mEq/L, and ketonuria) constituted cases, and children with type I diabetes without diabetic ketoacidosis constituted controls. None. Between 2005 and 2009, 32 cases and 50 controls were enrolled. Transcranial Doppler ultrasonography was used to measure middle cerebral artery flow velocities, and cerebral autoregulation testing was achieved via tilt-table testing. Cases underwent two and controls underwent one cerebral autoregulation test. Cerebral autoregulation was quantified by the autoregulatory index (autoregulatory index < 0.4 = impaired and autoregulatory index 0.4-1.0 = intact autoregulation). The first autoregulation test was obtained early (time 1, 12-24 hr; median [interquartile range], 8 hr [5-18 hr]) during diabetic ketoacidosis treatment, and a second autoregulation test was obtained during recovery (time 2, 36-72 hr; median [ interquartile range], 46 hr [40-59 hr]) from time 0 (defined as time of insulin start). Cases had lower autoregulatory index at time 1 than time 2 (p < 0.001) as well lower autoregulatory index than control subjects (p < 0.001). Cerebral autoregulation was impaired in 40% (n = 13) of cases at time 1 and in 6% (n = 2) of cases at time 2. Five cases (17%) showed persistent impairment of cerebral autoregulation between times 1 and 2 of treatment. All control subjects had intact cerebral autoregulation. Impaired cerebral autoregulation was common early during diabetic ketoacidosis treatment. Although the majority improved during diabetic ketoacidosis treatment, 17% of subjects had impairment between 36 and 72 hours after start of insulin therapy. The observed impaired cerebral

Near-source and Regional Experiments to Quantify Coupling and Propagation Effects of Seismic and Infrasound Signals from Mining Explosions

NASA Astrophysics Data System (ADS)

Stump, B. W.; Hayward, C.; Zhou, R.; House, S. M.

2001-12-01

Mining explosions designed to fragment rock are known to be regular sources of seismic waves as exemplified by the routine identification of these events in the USGS Mining Seismicity Report. Near-surface explosions can also generate low frequency acoustic waves or infrasound that can propagate through the atmosphere to regional distances. An understanding of source contributions to the size and character of waves initiated in the solid earth and atmosphere can be used to interpret propagation path effects as well as provide a physical understanding of characteristics that can be used for identifying the source type from the regional observations. The porphyry copper district of the SW United States was chosen for the study of these effects because of the existence of mining explosions that are routinely included in the USGS Mining Seismicity Report and an abundance of high quality regional seismic stations. A regional network of infrasound arrays was installed in order to quantify the accompanying low-frequency acoustic signals. In-mine seismic and acoustic measurements were made to quantify the source. These observations were supplemented with GPS locked video and in-mine documentation of the explosion design parameters. This comprehensive data set has been used to estimate source parameters that can be used to interpret the regional signals. Infrasound signals observed over a one-year time period indicate that the direction of atmospheric winds controls the amplitude and thus detection of these signals. Regional seismic observations are strongly affected by the style of blasting. The largest of the ground truth events (~250,000 kg explosive) are detonated in relatively long blasting sequences (~2 seconds) and produce some of the smallest regional signals. Smaller blasts (~25,000 to 50,000 kg) are detonated over relatively shorter time periods (`~0.2 to 0.4 seconds) and produce the largest regional signals. This source time function signature in the regional

Quantifying the Extremity of Windstorms for Regions Featuring Infrequent Events

NASA Astrophysics Data System (ADS)

Walz, M. A.; Leckebusch, G. C.; Kruschke, T.; Rust, H.; Ulbrich, U.

2017-12-01

This paper introduces the Distribution-Independent Storm Severity Index (DI-SSI). The DI-SSI represents an approach to quantify the severity of exceptional surface wind speeds of large scale windstorms that is complementary to the Storm Severity Index (SSI) introduced by Leckebusch et al. (2008). While the SSI approaches the extremeness of a storm from a meteorological and potential loss (impact) perspective, the DI-SSI defines the severity in a more climatological perspective. The idea is to assign equal index values to wind speeds of the same singularity (e.g. the 99th percentile) under consideration of the shape of the tail of the local wind speed climatology. Especially in regions at the edge of the classical storm track the DI-SSI shows more equitable severity estimates, e.g. for the extra-tropical cyclone Klaus. Here were compare the integral severity indices for several prominent windstorm in the European domain and discuss the advantages and disadvantages of the respective index. In order to compare the indices, their relation with the North Atlantic Oscillation (NAO) is studied, which is one of the main large scale drivers for the intensity of European windstorms. Additionally we can identify a significant relationship between the frequency and intensity of windstorms for large parts of the European domain.

Dynamic cerebral autoregulation during repeated squat-stand maneuvers

PubMed Central

Claassen, Jurgen A. H. R.; Levine, Benjamin D.; Zhang, Rong

2009-01-01

Transfer function analysis of spontaneous oscillations in blood pressure (BP) and cerebral blood flow (CBF) can quantify the dynamic relationship between BP and CBF. However, such oscillation amplitudes are often small and of questionable clinical significance, vary substantially, and cannot be controlled. At the very low frequencies (<0.07 Hz), coherence between BP and CBF often is low (<0.50) and their causal relationship is debated. Eight healthy subjects performed repeated squat-stand maneuvers to induce large oscillations in BP at frequencies of 0.025 and 0.05 Hz (very low frequency) and 0.1 Hz (low frequency), respectively. BP (Finapres), CBF velocity (CBFV; transcranial Doppler), and end-tidal CO2 (capnography) were monitored. Spectral analysis was used to quantify oscillations in BP and CBFV and to estimate transfer function phase, gain, and coherence. Compared with spontaneous oscillations, induced oscillations had higher coherence [mean 0.8 (SD 0.11); >0.5 in all subjects at all frequencies] and lower variability in phase estimates. However, gain estimates remained unchanged. Under both conditions, the “high-pass filter” characteristics of dynamic autoregulation were observed. In conclusion, using repeated squat-stand maneuvers, we were able to study dynamic cerebral autoregulation in the low frequencies under conditions of hemodynamically strong and causally related oscillations in BP and CBFV. This not only enhances the confidence of transfer function analysis as indicated by high coherence and improved phase estimation but also strengthens the clinical relevance of this method as induced oscillations in BP and CBFV mimic those associated with postural changes in daily life. PMID:18974368

Nonstationary multivariate modeling of cerebral autoregulation during hypercapnia.

PubMed

Kostoglou, Kyriaki; Debert, Chantel T; Poulin, Marc J; Mitsis, Georgios D

2014-05-01

We examined the time-varying characteristics of cerebral autoregulation and hemodynamics during a step hypercapnic stimulus by using recursively estimated multivariate (two-input) models which quantify the dynamic effects of mean arterial blood pressure (ABP) and end-tidal CO2 tension (PETCO2) on middle cerebral artery blood flow velocity (CBFV). Beat-to-beat values of ABP and CBFV, as well as breath-to-breath values of PETCO2 during baseline and sustained euoxic hypercapnia were obtained in 8 female subjects. The multiple-input, single-output models used were based on the Laguerre expansion technique, and their parameters were updated using recursive least squares with multiple forgetting factors. The results reveal the presence of nonstationarities that confirm previously reported effects of hypercapnia on autoregulation, i.e. a decrease in the MABP phase lead, and suggest that the incorporation of PETCO2 as an additional model input yields less time-varying estimates of dynamic pressure autoregulation obtained from single-input (ABP-CBFV) models. Copyright © 2013 IPEM. Published by Elsevier Ltd. All rights reserved.

Early postoperative changes in cerebral oxygen metabolism following neonatal cardiac surgery: Effects of surgical duration

PubMed Central

Buckley, Erin M.; Lynch, Jennifer M.; Goff, Donna A.; Schwab, Peter J.; Baker, Wesley B.; Durduran, Turgut; Busch, David R.; Nicolson, Susan C.; Montenegro, Lisa M.; Naim, Maryam Y.; Xiao, Rui; Spray, Thomas L.; Yodh, A. G.; Gaynor, J. William; Licht, Daniel J.

2013-01-01

Objective The early postoperative period following neonatal cardiac surgery is a time of increased risk for brain injury, yet the mechanisms underlying this risk are unknown. To understand these risks more completely, we quantified changes in postoperative cerebral metabolic rate of oxygen (CMRO2), oxygen extraction fraction (OEF), and cerebral blood flow (CBF) compared with preoperative levels by using noninvasive optical modalities. Methods Diffuse optical spectroscopy and diffuse correlation spectroscopy were used concurrently to derive cerebral blood flow and oxygen utilization postoperatively for 12 hours. Relative changes in CMRO2, OEF, and CBF were quantified with reference to preoperative data. A mixed-effect model was used to investigate the influence of total support time and deep hypothermic circulatory arrest duration on relative changes in CMRO2, OEF, and CBF. Results Relative changes in CMRO2, OEF, and CBF were assessed in 36 patients, 21 with single-ventricle defects and 15 with 2-ventricle defects. Among patients with single-ventricle lesions, deep hypothermic circulatory arrest duration did not affect relative changes in CMRO2, CBF, or OEF (P > .05). Among 2-ventricle patients, total support time was not a significant predictor of relative changes in CMRO2 or CBF (P > .05), although longer total support time was associated significantly with greater increases in relative change of postoperative OEF (P = .008). Conclusions Noninvasive diffuse optical techniques were used to quantify postoperative relative changes in CMRO2, CBF, and OEF for the first time in this observational pilot study. Pilot data suggest that surgical duration does not account for observed variability in the relative change in CMRO2, and that more comprehensive clinical studies using the new technology are feasible and warranted to elucidate these issues further. PMID:23111021

Effect of Toki-Shakuyaku-San on Regional Cerebral Blood Flow in Patients with Mild Cognitive Impairment and Alzheimer's Disease

PubMed Central

Matsuoka, Teruyuki; Narumoto, Jin; Shibata, Keisuke; Okamura, Aiko; Taniguchi, Shogo; Kitabayashi, Yurinosuke; Fukui, Kenji

2012-01-01

The aim of this study was to examine the effect of toki-shakuyaku-san (TSS) on mild cognitive impairment (MCI) and Alzheimer's disease (AD) using single-photon emission computed tomography (SPECT). All subjects were administered TSS (7.5 g/day) for eight weeks. SPECT and evaluations using the Mini Mental State Examination (MMSE), Neuropsychiatric Inventory, and Physical Self-Maintenance Scale were performed before and after treatment with TSS. Three patients with MCI and five patients with AD completed the study. No adverse events occurred during the study period. After treatment with TSS, regional cerebral blood flow (rCBF) in the posterior cingulate was significantly higher than that before treatment. No brain region showed a significant decrease in rCBF. TSS treatment also tended to improve the score for orientation to place on the MMSE. These results suggest that TSS could be useful for treatment of MCI and AD. PMID:22454658

Cerebral Palsy

MedlinePlus

Cerebral palsy is a group of disorders that affect a person's ability to move and to maintain balance ... do not get worse over time. People with cerebral palsy may have difficulty walking. They may also have ...

Regional cerebral blood flow changes associated with clitorally induced orgasm in healthy women.

PubMed

Georgiadis, Janniko R; Kortekaas, Rudie; Kuipers, Rutger; Nieuwenburg, Arie; Pruim, Jan; Reinders, A A T Simone; Holstege, Gert

2006-12-01

There is a severe lack of knowledge regarding the brain regions involved in human sexual performance in general, and female orgasm in particular. We used [15O]-H2O positron emission tomography to measure regional cerebral blood flow (rCBF) in 12 healthy women during a nonsexual resting state, clitorally induced orgasm, sexual clitoral stimulation (sexual arousal control) and imitation of orgasm (motor output control). Extracerebral markers of sexual performance and orgasm were rectal pressure variability (RPstd) and perceived level of sexual arousal (PSA). Sexual stimulation of the clitoris (compared to rest) significantly increased rCBF in the left secondary and right dorsal primary somatosensory cortex, providing the first account of neocortical processing of sexual clitoral information. In contrast, orgasm was mainly associated with profound rCBF decreases in the neocortex when compared with the control conditions (clitoral stimulation and imitation of orgasm), particularly in the left lateral orbitofrontal cortex, inferior temporal gyrus and anterior temporal pole. Significant positive correlations were found between RPstd and rCBF in the left deep cerebellar nuclei, and between PSA and rCBF in the ventral midbrain and right caudate nucleus. We propose that decreased blood flow in the left lateral orbitofrontal cortex signifies behavioural disinhibition during orgasm in women, and that deactivation of the temporal lobe is directly related to high sexual arousal. In addition, the deep cerebellar nuclei may be involved in orgasm-specific muscle contractions while the involvement of the ventral midbrain and right caudate nucleus suggests a role for dopamine in female sexual arousal and orgasm.

Zingiber officinale Mitigates Brain Damage and Improves Memory Impairment in Focal Cerebral Ischemic Rat

PubMed Central

Wattanathorn, Jintanaporn; Jittiwat, Jinatta; Tongun, Terdthai; Muchimapura, Supaporn; Ingkaninan, Kornkanok

2011-01-01

Cerebral ischemia is known to produce brain damage and related behavioral deficits including memory. Recently, accumulating lines of evidence showed that dietary enrichment with nutritional antioxidants could reduce brain damage and improve cognitive function. In this study, possible protective effect of Zingiber officinale, a medicinal plant reputed for neuroprotective effect against oxidative stress-related brain damage, on brain damage and memory deficit induced by focal cerebral ischemia was elucidated. Male adult Wistar rats were administrated an alcoholic extract of ginger rhizome orally 14 days before and 21 days after the permanent occlusion of right middle cerebral artery (MCAO). Cognitive function assessment was performed at 7, 14, and 21 days after MCAO using the Morris water maze test. The brain infarct volume and density of neurons in hippocampus were also determined. Furthermore, the level of malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) in cerebral cortex, striatum, and hippocampus was also quantified at the end of experiment. The results showed that cognitive function and neurons density in hippocampus of rats receiving ginger rhizome extract were improved while the brain infarct volume was decreased. The cognitive enhancing effect and neuroprotective effect occurred partly via the antioxidant activity of the extract. In conclusion, our study demonstrated the beneficial effect of ginger rhizome to protect against focal cerebral ischemia. PMID:21197427

Homolateral ataxia and crural paresis: a crossed cerebral-cerebellar diaschisis.

PubMed Central

Giroud, M; Creisson, E; Fayolle, H; Gras, P; Vion, P; Brunotte, F; Dumas, R

1994-01-01

A patient developed weakness of the right leg and homolateral ataxia of the arm, caused by a subcortical infarct in the area supplied by the anterior cerebral artery in the left paracentral region, demonstrated by CT and MRI. Cerebral blood flow studied by technetium-labelled hexamethyl-propylene-amine oxime using single photon emission computed tomography showed decreased blood flow in the left lateral frontal cortex and in the right cerebellar hemisphere ("crossed cerebral-cerebellar diaschisis"). The homolateral ataxia of the arm may be caused by decreased function of the right cerebellar hemisphere, because of a lesion of the corticopontine-cerebellar tracts, whereas crural hemiparesis is caused by a lesion of the upper part of the corona radiata. Images PMID:8126511

Effects of Fructose vs Glucose on Regional Cerebral Blood Flow in Brain Regions Involved With Appetite and Reward Pathways

PubMed Central

Page, Kathleen A.; Chan, Owen; Arora, Jagriti; Belfort-DeAguiar, Renata; Dzuira, James; Roehmholdt, Brian; Cline, Gary W.; Naik, Sarita; Sinha, Rajita; Constable, R. Todd; Sherwin, Robert S.

2014-01-01

Importance Increases in fructose consumption have paralleled the increasing prevalence of obesity, and high-fructose diets are thought to promote weight gain and insulin resistance. Fructose ingestion produces smaller increases in circulating satiety hormones compared with glucose ingestion, and central administration of fructose provokes feeding in rodents, whereas centrally administered glucose promotes satiety. Objective To study neurophysiological factors that might underlie associations between fructose consumption and weight gain. Design, Setting, and Participants Twenty healthy adult volunteers underwent 2 magnetic resonance imaging sessions at Yale University in conjunction with fructose or glucose drink ingestion in a blinded, random-order, crossover design. Main Outcome Measures Relative changes in hypothalamic regional cerebral blood flow (CBF) after glucose or fructose ingestion. Secondary outcomes included whole-brain analyses to explore regional CBF changes, functional connectivity analysis to investigate correlations between the hypothalamus and other brain region responses, and hormone responses to fructose and glucose ingestion. Results There was a significantly greater reduction in hypothalamic CBF after glucose vs fructose ingestion (–5.45 vs 2.84 mL/g per minute, respectively; mean difference, 8.3 mL/g per minute [95% CI of mean difference, 1.87-14.70]; P=.01). Glucose ingestion (compared with baseline) increased functional connectivity between the hypothalamus and the thalamus and striatum. Fructose increased connectivity between the hypothalamus and thalamus but not the striatum. Regional CBF within the hypothalamus, thalamus, insula, anterior cingulate, and striatum (appetite and reward regions) was reduced after glucose ingestion compared with baseline (P<.05 significance threshold, family-wise error [FWE] whole-brain corrected). In contrast, fructose reduced regional CBF in the thalamus, hippocampus, posterior cingulate cortex, fusiform

[Etiology of cerebral palsy].

PubMed

Jaisle, F

1996-01-01

The "perinatal asphyxia" is regarded to be one of the causes of cerebral palsy, though in the very most of the children with cerebral palsy there is found no hypoxia during labour. It should be mentioned, that the definition of "perinatal" and "asphyxia" neither are unic nor concret. And also there is no correlation between nonreassuring fetal heart rate patterns and acidosis in fetal blood with the incidence of cerebral palsy. Numerous studies in pregnant animals failed in proving an acute intrapartal hypoxia to be the origin of the cerebral palsy. Myers (1975) describes four patterns of anatomic brain damage after different injuries. Only his so called oligo-acidotic hypoxia, which is protracted and lasts over a longer time is leading to brain injury, which can be regarded in analogy to the injury of children with cerebral palsy. Summarising the update publications about the causes of cerebral palsy and the studies in pregnant animals there is no evidence that hypoxia during labour may be the cause of cerebral palsy. There is a great probability of a pre(and post-)natal origin of brain injury (for instance a periventricular leucomalacia found after birth) which leads to cerebral palsy. Short after labour signs of a so called "asphyxia" may occur in addition to this preexisting injury and misrepresent the cause of cerebral palsy. Finally the prepartal injury may cause both: Cerebral palsy and hypoxia.

Structural network alterations and neurological dysfunction in cerebral amyloid angiopathy

PubMed Central

Reijmer, Yael D.; Fotiadis, Panagiotis; Martinez-Ramirez, Sergi; Salat, David H.; Schultz, Aaron; Shoamanesh, Ashkan; Ayres, Alison M.; Vashkevich, Anastasia; Rosas, Diana; Schwab, Kristin; Leemans, Alexander; Biessels, Geert-Jan; Rosand, Jonathan; Johnson, Keith A.; Viswanathan, Anand; Gurol, M. Edip

2015-01-01

Cerebral amyloid angiopathy is a common form of small-vessel disease and an important risk factor for cognitive impairment. The mechanisms linking small-vessel disease to cognitive impairment are not well understood. We hypothesized that in patients with cerebral amyloid angiopathy, multiple small spatially distributed lesions affect cognition through disruption of brain connectivity. We therefore compared the structural brain network in patients with cerebral amyloid angiopathy to healthy control subjects and examined the relationship between markers of cerebral amyloid angiopathy-related brain injury, network efficiency, and potential clinical consequences. Structural brain networks were reconstructed from diffusion-weighted magnetic resonance imaging in 38 non-demented patients with probable cerebral amyloid angiopathy (69 ± 10 years) and 29 similar aged control participants. The efficiency of the brain network was characterized using graph theory and brain amyloid deposition was quantified by Pittsburgh compound B retention on positron emission tomography imaging. Global efficiency of the brain network was reduced in patients compared to controls (0.187 ± 0.018 and 0.201 ± 0.015, respectively, P < 0.001). Network disturbances were most pronounced in the occipital, parietal, and posterior temporal lobes. Among patients, lower global network efficiency was related to higher cortical amyloid load (r = −0.52; P = 0.004), and to magnetic resonance imaging markers of small-vessel disease including increased white matter hyperintensity volume (P < 0.001), lower total brain volume (P = 0.02), and number of microbleeds (trend P = 0.06). Lower global network efficiency was also related to worse performance on tests of processing speed (r = 0.58, P < 0.001), executive functioning (r = 0.54, P = 0.001), gait velocity (r = 0.41, P = 0.02), but not memory. Correlations with cognition were independent of age, sex, education level, and other magnetic resonance imaging

Interharmonic modulation products as a means to quantify nonlinear D-region interactions

NASA Astrophysics Data System (ADS)

Moore, Robert

Experimental observations performed during dual beam ionospheric HF heating experiments at the High frequency Active Auroral Research Program (HAARP) HF transmitter in Gakona, Alaska are used to quantify the relative importance of specific nonlinear interactions that occur within the D region ionosphere. During these experiments, HAARP broadcast two amplitude modulated HF beams whose center frequencies were separated by less than 20 kHz. One beam was sinusoidally modulated at 500 Hz while the second beam was sinusoidally modulated using a 1-7 kHz linear frequency-time chirp. ELF/VLF observations performed at two different locations (3 and 98 km from HAARP) provide clear evidence of strong interactions between all field components of the two HF beams in the form of low and high order interharmonic modulation products. From a theoretical standpoint, the observed interharmonic modulation products could be produced by several different nonlinearities. The two primary nonlinearities take the form of wave-medium interactions (i.e., cross modulation), wherein the ionospheric conductivity modulation produced by one signal crosses onto the other signal via collision frequency modification, and wave-wave interactions, wherein the conduction current associated with one wave mixes with the electric field of the other wave to produce electron temperature oscillations. We are able to separate and quantify these two different nonlinearities, and we conclude that the wave-wave interactions dominate the wave-medium interactions by a factor of two. These results are of great importance for the modeling of transioinospheric radio wave propagation, in that both the wave-wave and the wave-medium interactions could be responsible for a significant amount of anomalous absorption.

Genetic modification of cerebral arterial wall: implications for prevention and treatment of cerebral vasospasm.

PubMed

Vijay, Anantha; Santhanam, R; Katusic, Zvonimir S

2006-10-01

Genetic modification of cerebral vessels represents a promising and novel approach for prevention and/or treatment of various cerebral vascular disorders, including cerebral vasospasm. In this review, we focus on the current understanding of the use of gene transfer to the cerebral arteries for prevention and/or treatment of cerebral vasospasm following subarachnoid hemorrhage (SAH). We also discuss the recent developments in vascular therapeutics, involving the autologous use of progenitor cells for repair of damaged vessels, as well as a cell-based gene delivery approach for the prevention and treatment of cerebral vasospasm.

Altered cerebral hemodyamics and cortical thinning in asymptomatic carotid artery stenosis.

PubMed

Marshall, Randolph S; Asllani, Iris; Pavol, Marykay A; Cheung, Ying-Kuen; Lazar, Ronald M

2017-01-01

Cortical thinning is a potentially important biomarker, but the pathophysiology in cerebrovascular disease is unknown. We investigated the association between regional cortical blood flow and regional cortical thickness in patients with asymptomatic unilateral high-grade internal carotid artery disease without stroke. Twenty-nine patients underwent high resolution anatomical and single-delay, pseudocontinuous arterial spin labeling magnetic resonance imaging with partial volume correction to assess gray matter baseline flow. Cortical thickness was estimated using Freesurfer software, followed by co-registration onto each patient's cerebral blood flow image space. Paired t-tests assessed regional cerebral blood flow in motor cortex (supplied by the carotid artery) and visual cortex (indirectly supplied by the carotid) on the occluded and unoccluded side. Pearson correlations were calculated between cortical thickness and regional cerebral blood flow, along with age, hypertension, diabetes and white matter hyperintensity volume. Multiple regression and generalized estimating equation were used to predict cortical thickness bilaterally and in each hemisphere separately. Cortical blood flow correlated with thickness in motor cortex bilaterally (p = 0.0002), and in the occluded and unoccluded sides individually; age (p = 0.002) was also a predictor of cortical thickness in the motor cortex. None of the variables predicted cortical thickness in visual cortex. Blood flow was significantly lower on the occluded versus unoccluded side in the motor cortex (p<0.0001) and in the visual cortex (p = 0.018). On average, cortex was thinner on the side of occlusion in motor but not in visual cortex. The association between cortical blood flow and cortical thickness in carotid arterial territory with greater thinning on the side of the carotid occlusion suggests that altered cerebral hemodynamics is a factor in cortical thinning.

Prospective pilot study of cerebral near infrared spectroscopy monitoring during pre-hospital anaesthesia.

PubMed

Ångerman, S; Länkimäki, S; Neuvonen, N; Kirves, H; Nurmi, J

2018-05-22

Near-infrared spectroscopy (NIRS) provides a non-invasive measure of cerebral tissue oxygenation. The literature on application of this method in pre-hospital setting is limited. The aims of this study were to determine the feasibility of cerebral NIRS during pre-hospital anaesthesia and to quantify the changes in front lobe regional oxygen saturation (rSO 2 ) during the pre-hospital phase. NIRS monitoring (Nonin SenSmart X-100) of front lobe regional oxygen saturation (rSO2) was initiated before induction of anaesthesia in 31 adult patients and continued until hospital arrival. The median age of the patients was 55 years (IQR [range] 43-63 [20-84]), and 20 (65%) of the patients were male. The indications for pre-hospital anaesthesia were neurological reasons (29%), intoxication (23%), traumatic brain injury (23%) and successful resuscitation from cardiac arrest (16%). The NIRS monitoring was successful in 29 of 31 cases (94%; 95% CI: 78-99). One patient could not be monitored due to poor probe-skin contact, and 1 patient had poor contact with 1 hemisphere. Monitoring was performed for a total of 1335 minutes and was successful in both hemispheres 95% (95% CI: 94-96) of the time. The median lowest rSO 2 was 8% (IQR [range] 2-13 [0-30]) below baseline, and median peak rSO 2 was 7% (IQR [range] 2-11 [0-34]) above the baseline. Changes in rSO 2 without accompanying changes in vital signs were observed. NIRS is feasible during pre-hospital anaesthesia and substantial changes were observed in some patients. It provides data beyond the standard monitoring used in the pre-hospital setting. © 2018 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

The Role of Neuronal Signaling in Controlling Cerebral Blood Flow

ERIC Educational Resources Information Center

Drake, Carrie T.; Iadecola, Costantino

2007-01-01

Well-regulated blood flow within the brain is vital to normal function. The brain's requirement for sufficient blood flow is ensured by a tight link between neural activity and blood flow. The link between regional synaptic activity and regional cerebral blood flow, termed functional hyperemia, is the basis for several modern imaging techniques…

Emesis, radiation exposure, and local cerebral blood flow in the ferret

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tuor, U.I.; Kondysar, M.H.; Harding, R.K.

1988-06-01

We examined the sensitivity of the ferret to emetic stimuli and the effect of radiation exposure near the time of emesis on local cerebral blood flow. Ferrets vomited following the administration of either apomorphine (approx 45% of the ferrets tested) or peptide YY (approx 36% of those tested). Exposure to radiation was a very potent emetic stimulus, but vomiting could be prevented by restraint of the hindquarters of the ferret. Local cerebral blood flow was measured using a quantitative autoradiographic technique and with the exception of several regions in the telencephalon and cerebellum, local cerebral blood flow in the ferretmore » was similar to that in the rat. In animals with whole-body exposure to moderate levels of radiation (4 Gy of /sup 137/Cs), mean arterial blood pressure was similar to that in the control group. However, 15-25 min following irradiation there was a general reduction of local cerebral blood flow ranging from 7 to 33% of that in control animals. These cerebral blood flow changes likely correspond to a reduced activation of the central nervous system.« less

Feasibility of absolute cerebral tissue oxygen saturation during cardiopulmonary resuscitation.

PubMed

Meex, Ingrid; De Deyne, Cathy; Dens, Jo; Scheyltjens, Simon; Lathouwers, Kevin; Boer, Willem; Vundelinckx, Guy; Heylen, René; Jans, Frank

2013-03-01

Current monitoring during cardiopulmonary resuscitation (CPR) is limited to clinical observation of consciousness, breathing pattern and presence of a pulse. At the same time, the adequacy of cerebral oxygenation during CPR is critical for neurological outcome and thus survival. Cerebral oximetry, based on near-infrared spectroscopy (NIRS), provides a measure of brain oxygen saturation. Therefore, we examined the feasibility of using NIRS during CPR. Recent technologies (FORE-SIGHT™ and EQUANOX™) enable the monitoring of absolute cerebral tissue oxygen saturation (SctO2) values without the need for pre-calibration. We tested both FORE-SIGHT™ (five patients) and EQUANOX Advance™ (nine patients) technologies in the in-hospital as well as the out-of-hospital CPR setting. In this observational study, values were not utilized in any treatment protocol or therapeutic decision. An independent t-test was used for statistical analysis. Our data demonstrate the feasibility of both technologies to measure cerebral oxygen saturation during CPR. With the continuous, pulseless near-infrared wave analysis of both FORE-SIGHT™ and EQUANOX™ technology, we obtained SctO2 values in the absence of spontaneous circulation. Both technologies were able to assess the efficacy of CPR efforts: improved resuscitation efforts (improved quality of chest compressions with switch of caregivers) resulted in higher SctO2 values. Until now, the ability of CPR to provide adequate tissue oxygenation was difficult to quantify or to assess clinically due to a lack of specific technology. With both technologies, any change in hemodynamics (for example, ventricular fibrillation) results in a reciprocal change in SctO2. In some patients, a sudden drop in SctO2 was the first warning sign of reoccurring ventricular fibrillation. Both the FORE-SIGHT™ and EQUANOX™ technology allow non-invasive monitoring of the cerebral oxygen saturation during CPR. Moreover, changes in SctO2 values might be

Regional flux analysis for discovering and quantifying anatomical changes: An application to the brain morphometry in Alzheimer's disease.

PubMed

Lorenzi, M; Ayache, N; Pennec, X

2015-07-15

In this study we introduce the regional flux analysis, a novel approach to deformation based morphometry based on the Helmholtz decomposition of deformations parameterized by stationary velocity fields. We use the scalar pressure map associated to the irrotational component of the deformation to discover the critical regions of volume change. These regions are used to consistently quantify the associated measure of volume change by the probabilistic integration of the flux of the longitudinal deformations across the boundaries. The presented framework unifies voxel-based and regional approaches, and robustly describes the volume changes at both group-wise and subject-specific level as a spatial process governed by consistently defined regions. Our experiments on the large cohorts of the ADNI dataset show that the regional flux analysis is a powerful and flexible instrument for the study of Alzheimer's disease in a wide range of scenarios: cross-sectional deformation based morphometry, longitudinal discovery and quantification of group-wise volume changes, and statistically powered and robust quantification of hippocampal and ventricular atrophy. Copyright © 2015 Elsevier Inc. All rights reserved.

Changes in cerebral glucose metabolism during early abstinence from chronic methamphetamine abuse.

PubMed

Berman, S M; Voytek, B; Mandelkern, M A; Hassid, B D; Isaacson, A; Monterosso, J; Miotto, K; Ling, W; London, E D

2008-09-01

Changes in brain function during the initial weeks of abstinence from chronic methamphetamine abuse may substantially affect clinical outcome, but are not well understood. We used positron emission tomography with [F-18]fluorodeoxyglucose (FDG) to quantify regional cerebral glucose metabolism, an index of brain function, during performance of a vigilance task. A total of 10 methamphetamine-dependent subjects were tested after 5-9 days of abstinence, and after 4 additional weeks of supervised abstinence. A total of 12 healthy control subjects were tested at corresponding times. Global glucose metabolism increased between tests (P=0.01), more in methamphetamine-dependent (10.9%, P=0.02) than control subjects (1.9%, NS). Glucose metabolism did not change in subcortical regions of methamphetamine-dependent subjects, but increased in neocortex, with maximal increase (>20%) in parietal regions. Changes in reaction time and self-reports of negative affect varied more in methamphetamine-dependent than in control subjects, and correlated both with the increase in parietal glucose metabolism, and decrease in relative activity (after scaling to the global mean) in some regions. A robust relationship between change in self-reports of depressive symptoms and relative activity in the ventral striatum may have great relevance to treatment success because of the role of this region in drug abuse-related behaviors. Shifts in cortical-subcortical metabolic balance either reflect new processes that occur during early abstinence, or the unmasking of effects of chronic methamphetamine abuse that are obscured by suppression of cortical glucose metabolism that continues for at least 5-9 days after cessation of methamphetamine self-administration.

Cerebral Atrophy

MedlinePlus

... Alzheimer’s disease, Pick’s disease, and fronto-temporal dementia cerebral palsy , in which lesions (damaged areas) may impair motor ... Alzheimer’s disease, Pick’s disease, and fronto-temporal dementia cerebral palsy , in which lesions (damaged areas) may impair motor ...

Up-regulation of cerebral cytochrome-c-oxidase and hemodynamics by transcranial infrared laser stimulation: A broadband near-infrared spectroscopy study.

PubMed

Wang, Xinlong; Tian, Fenghua; Reddy, Divya D; Nalawade, Sahil S; Barrett, Douglas W; Gonzalez-Lima, Francisco; Liu, Hanli

2017-12-01

Transcranial infrared laser stimulation (TILS) is a noninvasive form of brain photobiomulation. Cytochrome-c-oxidase (CCO), the terminal enzyme in the mitochondrial electron transport chain, is hypothesized to be the primary intracellular photoacceptor. We hypothesized that TILS up-regulates cerebral CCO and causes hemodynamic changes. We delivered 1064-nm laser stimulation to the forehead of healthy participants ( n = 11), while broadband near-infrared spectroscopy was utilized to acquire light reflectance from the TILS-treated cortical region before, during, and after TILS. Placebo experiments were also performed for accurate comparison. Time course of spectroscopic readings were analyzed and fitted to the modified Beer-Lambert law. With respect to the placebo readings, we observed (1) significant increases in cerebral concentrations of oxidized CCO (Δ[CCO]; >0.08 µM; p < 0.01), oxygenated hemoglobin (Δ[HbO]; >0.8 µM; p < 0.01), and total hemoglobin (Δ[HbT]; >0.5 µM; p < 0.01) during and after TILS, and (2) linear interplays between Δ[CCO] versus Δ[HbO] and between Δ[CCO] versus Δ[HbT]. Ratios of Δ[CCO]/Δ[HbO] and Δ[CCO]/Δ[HbT] were introduced as TILS-induced metabolic-hemodynamic coupling indices to quantify the coupling strength between TILS-enhanced cerebral metabolism and blood oxygen supply. This study provides the first demonstration that TILS causes up-regulation of oxidized CCO in the human brain, and contributes important insight into the physiological mechanisms.

Cerebral Palsy. Fact Sheet = La Paralisis Cerebral. Hojas Informativas Sobre Discapacidades.

ERIC Educational Resources Information Center

National Information Center for Children and Youth with Disabilities, Washington, DC.

This fact sheet on cerebral palsy is written in both English and Spanish. First, it provides a definition of cerebral palsy and considers various causes (e.g., an insufficient amount of oxygen reaching the fetal or newborn brain). The fact sheet then offers incidence figures and explains characteristics of the three main types of cerebral palsy:…

Pre-treatment with Chrysanthemum indicum Linné extract protects pyramidal neurons from transient cerebral ischemia via increasing antioxidants in the gerbil hippocampal CA1 region

PubMed Central

Kim, In Hye; Lee, Tae-Kyeong; Cho, Jeong Hwi; Lee, Jae-Chul; Park, Joon Ha; Ahn, Ji Hyeon; Shin, Bich-Na; Chen, Bai Hui; Tae, Hyun-Jin; Kim, Yang Hee; Kim, Jong-Dai; Kim, Young-Myeong; Won, Moo-Ho; Kang, Il Jun

2017-01-01

Chrysanthemum indicum Linné extract (CIL) is used in herbal medicine in East Asia. In the present study, gerbils were orally pre-treated with CIL, and changes of antioxidant enzymes including superoxide dismutase (SOD) 1 and SOD2, catalase (CAT) and glutathione peroxidase (GPX) in the hippocampal CA1 region following 5 min of transient cerebral ischemia were investigated and the neuroprotective effect of CIL in the ischemic CA1 region was examined. SOD1, SOD2, CAT and GPX immunoreactivities were observed in the pyramidal cells of the CA1 region and their immunoreactivities were gradually decreased following ischemia-reperfusion and barely detectable at 5 days post-ischemia. CIL pre-treatment significantly increased immunoreactivities of SOD1, CAT and GPX, but not SOD2, in the CA1 pyramidal cells of the sham-operated animals. In addition, SOD1, SOD2, CAT and GPX immunoreactivities in the CA1 pyramidal cells were significantly higher compared with the ischemia-operated animals. Furthermore, it was identified that pre-treatment with CIL protected the CA1 pyramidal cells in the CA1 region using neuronal nuclei immunohistochemistry and Fluoro-Jade B histofluorescence staining; the protected CA1 pyramidal cells were 67.5% compared with the sham-operated animals. In conclusion, oral CIL pre-treatment increased endogenous antioxidant enzymes in CA1 pyramidal cells in the gerbil hippocampus and protected the cells from transient cerebral ischemic insult. This finding suggested that CIL is promising for the prevention of ischemia-induced neuronal damage. PMID:28534982

Chronic hyperperfusion and angiogenesis follow subacute hypoperfusion in the thalamus of rats with focal cerebral ischemia

PubMed Central

Hayward, Nick MEA; Yanev, Pavel; Haapasalo, Annakaisa; Miettinen, Riitta; Hiltunen, Mikko; Gröhn, Olli; Jolkkonen, Jukka

2011-01-01

Cerebral blood flow (CBF) is disrupted after focal ischemia in rats. We examined long-term hemodynamic and cerebrovascular changes in the rat thalamus after focal cerebral ischemia. Cerebral blood flow quantified by arterial spin labeling magnetic resonance imaging was decreased in the ipsilateral and contralateral thalamus 2 days after cerebral ischemia. Partial thalamic CBF recovery occurred by day 7, then the ipsilateral thalamus was chronically hyperperfused at 30 days and 3 months compared with its contralateral side. This contrasted with permanent hypoperfusion in the ipsilateral cortex. Angiogenesis was indicated by endothelial cell (RECA-1) immunohistochemistry that showed increased blood vessel branching in the ipsilateral thalamus at the end of the 3-month follow-up. Only transient thalamic IgG extravasation was observed, indicating that the blood–brain barrier was intact after day 2. Angiogenesis was preceded by transiently altered expression levels of cadherin family adhesion molecules, cadherin-7, protocadherin-1, and protocadherin-17. In conclusion, thalamic pathology after focal cerebral ischemia involved long-term hemodynamic changes and angiogenesis preceded by altered expression of vascular adhesion factors. Postischemic angiogenesis in the thalamus represents a novel type of remote plasticity, which may support removal of necrotic brain tissue and aid functional recovery. PMID:21081957

Regional cerebral blood flow assessed by single photon emission computed tomography (SPECT) in dogs with congenital portosystemic shunt and hepatic encephalopathy.

PubMed

Or, Matan; Peremans, Kathelijne; Martlé, Valentine; Vandermeulen, Eva; Bosmans, Tim; Devriendt, Nausikaa; de Rooster, Hilde

2017-02-01

Regional cerebral blood flow (rCBF) in eight dogs with congenital portosystemic shunt (PSS) and hepatic encephalopathy (HE) was compared with rCBF in eight healthy control dogs using single photon emission computed tomography (SPECT) with a 99m technetium-hexamethylpropylene amine oxime ( 99m Tc-HMPAO) tracer. SPECT scans were abnormal in all PSS dogs. Compared to the control group, rCBF in PSS dogs was significantly decreased in the temporal lobes and increased in the subcortical (thalamic and striatal) area. Brain perfusion imaging alterations observed in the dogs with PSS and HE are similar to those in human patients with HE. These findings suggest that dogs with HE and PSS have altered perfusion of mainly the subcortical and the temporal regions of the brain. Copyright © 2016 Elsevier Ltd. All rights reserved.

A Nonlinear Dynamic Approach Reveals a Long-Term Stroke Effect on Cerebral Blood Flow Regulation at Multiple Time Scales

PubMed Central

Hu, Kun; Lo, Men-Tzung; Peng, Chung-Kang; Liu, Yanhui; Novak, Vera

2012-01-01

Cerebral autoregulation (CA) is an important vascular control mechanism responsible for relatively stable cerebral blood flow despite changes of systemic blood pressure (BP). Impaired CA may leave brain tissue unprotected against potentially harmful effects of BP fluctuations. It is generally accepted that CA is less effective or even inactive at frequencies >∼0.1 Hz. Without any physiological foundation, this concept is based on studies that quantified the coupling between BP and cerebral blood flow velocity (BFV) using transfer function analysis. This traditional analysis assumes stationary oscillations with constant amplitude and period, and may be unreliable or even invalid for analysis of nonstationary BP and BFV signals. In this study we propose a novel computational tool for CA assessment that is based on nonlinear dynamic theory without the assumption of stationary signals. Using this method, we studied BP and BFV recordings collected from 39 patients with chronic ischemic infarctions and 40 age-matched non-stroke subjects during baseline resting conditions. The active CA function in non-stroke subjects was associated with an advanced phase in BFV oscillations compared to BP oscillations at frequencies from ∼0.02 to 0.38 Hz. The phase shift was reduced in stroke patients even at > = 6 months after stroke, and the reduction was consistent at all tested frequencies and in both stroke and non-stroke hemispheres. These results provide strong evidence that CA may be active in a much wider frequency region than previously believed and that the altered multiscale CA in different vascular territories following stroke may have important clinical implications for post-stroke recovery. Moreover, the stroke effects on multiscale cerebral blood flow regulation could not be detected by transfer function analysis, suggesting that nonlinear approaches without the assumption of stationarity are more sensitive for the assessment of the coupling of nonstationary

Middle cerebral artery diameter changes during rhythmic handgrip exercise in humans.

PubMed

Verbree, J; Bronzwaer, Agt; van Buchem, M A; Daemen, Mjap; van Lieshout, J J; van Osch, Mjp

2017-08-01

Transcranial Doppler (TCD) sonography is a frequently employed technique for quantifying cerebral blood flow by assuming a constant arterial diameter. Given that exercise increases arterial pressure by sympathetic activation, we hypothesized that exercise might induce a change in the diameter of large cerebral arteries. Middle cerebral artery (MCA) cross-sectional area was assessed in response to handgrip exercise by direct magnetic resonance imaging (MRI) observations. Twenty healthy subjects (11 female) performed three 5 min bouts of rhythmic handgrip exercise at 60% maximum voluntary contraction, alternated with 5 min of rest. High-resolution 7 T MRI scans were acquired perpendicular to the MCA. Two blinded observers manually determined the MCA cross-sectional area. Sufficient image quality was obtained in 101 MCA-scans of 19 subjects (age-range 20-59 years). Mixed effects modelling showed that the MCA cross-sectional area decreased by 2.1 ± 0.8% (p = 0.01) during handgrip, while the heart rate increased by 11 ± 2% (p < 0.001) at constant end-tidal CO 2 (p = 0.10). In conclusion, the present study showed a 2% decrease in MCA cross-sectional area during rhythmic handgrip exercise. This further strengthens the current concept of sympathetic control of large cerebral arteries, showing in vivo vasoconstriction during exercise-induced sympathetic activation. Moreover, care must be taken when interpreting TCD exercise studies as diameter constancy cannot be assumed.

Subchronic exposure of benzo(a)pyrene interferes with the expression of Bcl-2, Ki-67, C-myc and p53, Bax, Caspase-3 in sub-regions of cerebral cortex and hippocampus.

PubMed

He, Jianlong; Ji, Xiaoying; Li, Yongfei; Xue, Xiaochang; Feng, Guodong; Zhang, Huqin; Wang, Huichun; Gao, Meilii

2016-01-01

Benzo[a]pyrene [B(a)P], a representative substance of the polycyclic aromatic hydrocarbons, is an ubiquitous environmental contaminant. However, the mechanism of B(a)P neurotoxicity is still not clear. The aim of this study was to investigate the molecular mechanism by assay the expression of Bcl-2, C-myc, Ki-67 oncogene and p53, Bax, Caspase-3 proapoptotic gene in sub-regions of cerebral cortex and hippocampus in brain. Mice were administrated with subchronic intraperitoneal injection and oral gavage of B(a)P (2.5, 5, 10mg/kg body weight) for 13 weeks. We observed that B(a)P induced the significant increase in relative brain weights and the slight proliferation phenomenon in hippocampus in the experiment. Significant increase of C-myc, Ki-67 and p53, Bax, Caspase-3 and dramatic decrease of Bcl-2 protein levels were observed through immunohistochemical analysis. The relative higher interference of Bcl-2, C-myc, Ki-67 and p53, Bax, Caspase-3 proteins was observed in hippocampus sub-regions of dentate gyrus, cornu ammonis 3 and cornu ammonis 1. The relative lower interference of the examined genes was found in cerebral cortex sub-regions of frontal cortex, temporal cortex and parietal cortex. The results showed a region-difference manner with accompanying dose-dependent manner in brain hippocampus and cerebral cortex induced by B(a)P. These findings indicate that B(a)P-induced subchronic neural toxicity may occur through the enhancement in Bcl-2, C-myc, Ki-67 oncogenes and p53, Bax, Caspase-3 proapoptotic genes expression. Copyright © 2015 Elsevier GmbH. All rights reserved.

Is Vasomotion in Cerebral Arteries Impaired in Alzheimer’s Disease?

PubMed Central

Di Marco, Luigi Yuri; Farkas, Eszter; Martin, Chris; Venneri, Annalena; Frangi, Alejandro F.

2015-01-01

Abstract A substantial body of evidence supports the hypothesis of a vascular component in the pathogenesis of Alzheimer’s disease (AD). Cerebral hypoperfusion and blood-brain barrier dysfunction have been indicated as key elements of this pathway. Cerebral amyloid angiopathy (CAA) is a cerebrovascular disorder, frequent in AD, characterized by the accumulation of amyloid-β (Aβ) peptide in cerebral blood vessel walls. CAA is associated with loss of vascular integrity, resulting in impaired regulation of cerebral circulation, and increased susceptibility to cerebral ischemia, microhemorrhages, and white matter damage. Vasomotion— the spontaneous rhythmic modulation of arterial diameter, typically observed in arteries/arterioles in various vascular beds including the brain— is thought to participate in tissue perfusion and oxygen delivery regulation. Vasomotion is impaired in adverse conditions such as hypoperfusion and hypoxia. The perivascular and glymphatic pathways of Aβ clearance are thought to be driven by the systolic pulse. Vasomotion produces diameter changes of comparable amplitude, however at lower rates, and could contribute to these mechanisms of Aβ clearance. In spite of potential clinical interest, studies addressing cerebral vasomotion in the context of AD/CAA are limited. This study reviews the current literature on vasomotion, and hypothesizes potential paths implicating impaired cerebral vasomotion in AD/CAA. Aβ and oxidative stress cause vascular tone dysregulation through direct effects on vascular cells, and indirect effects mediated by impaired neurovascular coupling. Vascular tone dysregulation is further aggravated by cholinergic deficit and results in depressed cerebrovascular reactivity and (possibly) impaired vasomotion, aggravating regional hypoperfusion and promoting further Aβ and oxidative stress accumulation. PMID:25720414

Hyperventilation, cerebral perfusion, and syncope.

PubMed

Immink, R V; Pott, F C; Secher, N H; van Lieshout, J J

2014-04-01

This review summarizes evidence in humans for an association between hyperventilation (HV)-induced hypocapnia and a reduction in cerebral perfusion leading to syncope defined as transient loss of consciousness (TLOC). The cerebral vasculature is sensitive to changes in both the arterial carbon dioxide (PaCO2) and oxygen (PaO2) partial pressures so that hypercapnia/hypoxia increases and hypocapnia/hyperoxia reduces global cerebral blood flow. Cerebral hypoperfusion and TLOC have been associated with hypocapnia related to HV. Notwithstanding pronounced cerebrovascular effects of PaCO2 the contribution of a low PaCO2 to the early postural reduction in middle cerebral artery blood velocity is transient. HV together with postural stress does not reduce cerebral perfusion to such an extent that TLOC develops. However when HV is combined with cardiovascular stressors like cold immersion or reduced cardiac output brain perfusion becomes jeopardized. Whether, in patients with cardiovascular disease and/or defect, cerebral blood flow cerebral control HV-induced hypocapnia elicits cerebral hypoperfusion, leading to TLOC, remains to be established.

Phase-contrast MRI versus numerical simulation to quantify hemodynamical changes in cerebral aneurysms after flow diverter treatment

PubMed Central

Frolov, Sergey; Prothmann, Sascha; Liepsch, Dieter; Balasso, Andrea; Berg, Philipp; Kaczmarz, Stephan; Kirschke, Jan Stefan

2018-01-01

Cerebral aneurysms are a major risk factor for intracranial bleeding with devastating consequences for the patient. One recently established treatment is the implantation of flow-diverters (FD). Methods to predict their treatment success before or directly after implantation are not well investigated yet. The aim of this work was to quantitatively study hemodynamic parameters in patient-specific models of treated cerebral aneurysms and its correlation with the clinical outcome. Hemodynamics were evaluated using both computational fluid dynamics (CFD) and phase contrast (PC) MRI. CFD simulations and in vitro MRI measurements were done under similar flow conditions and results of both methods were comparatively analyzed. For preoperative and postoperative distribution of hemodynamic parameters, CFD simulations and PC-MRI velocity measurements showed similar results. In both cases where no occlusion of the aneurysm was observed after six months, a flow reduction of about 30-50% was found, while in the clinically successful case with complete occlusion of the aneurysm after 6 months, the flow reduction was about 80%. No vortex was observed in any of the three models after treatment. The results are in agreement with recent studies suggesting that CFD simulations can predict post-treatment aneurysm flow alteration already before implantation of a FD and PC-MRI could validate the predicted hemodynamic changes right after implantation of a FD. PMID:29304062

Metabolic Characterization of Acutely Isolated Hippocampal and Cerebral Cortical Slices Using [U-13C]Glucose and [1,2-13C]Acetate as Substrates.

PubMed

McNair, Laura F; Kornfelt, Rasmus; Walls, Anne B; Andersen, Jens V; Aldana, Blanca I; Nissen, Jakob D; Schousboe, Arne; Waagepetersen, Helle S

2017-03-01

Brain slice preparations from rats, mice and guinea pigs have served as important tools for studies of neurotransmission and metabolism. While hippocampal slices routinely have been used for electrophysiology studies, metabolic processes have mostly been studied in cerebral cortical slices. Few comparative characterization studies exist for acute hippocampal and cerebral cortical slices, hence, the aim of the current study was to characterize and compare glucose and acetate metabolism in these slice preparations in a newly established incubation design. Cerebral cortical and hippocampal slices prepared from 16 to 18-week-old mice were incubated for 15-90 min with unlabeled glucose in combination with [U- 13 C]glucose or [1,2- 13 C]acetate. Our newly developed incubation apparatus allows accurate control of temperature and is designed to avoid evaporation of the incubation medium. Subsequent to incubation, slices were extracted and extracts analyzed for 13 C-labeling (%) and total amino acid contents (µmol/mg protein) using gas chromatography-mass spectrometry and high performance liquid chromatography, respectively. Release of lactate from the slices was quantified by analysis of the incubation media. Based on the measured 13 C-labeling (%), total amino acid contents and relative activity of metabolic enzymes/pathways, we conclude that the slice preparations in the current incubation apparatus exhibited a high degree of metabolic integrity. Comparison of 13 C-labeling observed with [U- 13 C]glucose in slices from cerebral cortex and hippocampus revealed no significant regional differences regarding glycolytic or total TCA cycle activities. On the contrary, results from the incubations with [1,2- 13 C]acetate suggest a higher capacity of the astrocytic TCA cycle in hippocampus compared to cerebral cortex. Finally, we propose a new approach for assessing compartmentation of metabolite pools between astrocytes and neurons using 13 C-labeling (%) data obtained from

MDMA ‘ecstasy’ increases cerebral cortical perfusion determined by bolus-tracking arterial spin labelling (btASL) MRI

PubMed Central

Rouine, J; Gobbo, O L; Campbell, M; Gigliucci, V; Ogden, I; McHugh Smith, K; Duffy, P; Behan, B; Byrne, D; Kelly, M E; Blau, C W; Kerskens, C M; Harkin, A

2013-01-01

Background and Purpose The purpose of this study was to assess cerebral perfusion changes following systemic administration of the recreational drug 3,4-methylendioxymethamphetamine (MDMA ‘ecstasy’) to rats. Experimental Approach Cerebral perfusion was quantified using bolus-tracking arterial spin labelling (btASL) MRI. Rats received MDMA (20 mg·kg−1; i.p.) and were assessed 1, 3 or 24 h later. Rats received MDMA (5 or 20 mg·kg−1; i.p.) and were assessed 3 h later. In addition, rats received MDMA (5 or 10 mg·kg−1; i.p.) or saline four times daily over 2 consecutive days and were assessed 8 weeks later. Perfusion-weighted images were generated in a 7 tesla (7T) MRI scanner and experimental data was fitted to a quantitative model of cerebral perfusion to generate mean transit time (MTT), capillary transit time (CTT) and signal amplitude. Key Results MDMA reduces MTT and CTT and increases amplitude in somatosensory and motor cortex 1 and 3 h following administration, indicative of an increase in perfusion. Prior exposure to MDMA provoked a long-term reduction in cortical 5-HT concentration, but did not produce a sustained effect on cerebral cortical perfusion. The response to acute MDMA challenge (20 mg·kg−1; i.p.) was attenuated in these animals indicating adaptation in response to prior MDMA exposure. Conclusions and Implications MDMA provokes changes in cortical perfusion, which are quantifiable by btASL MRI, a neuroimaging tool with translational potential. Future studies are directed towards elucidation of the mechanisms involved and correlating changes in cerebrovascular function with potential behavioural deficits associated with drug use. PMID:23517012

Noninvasive MRI measurement of the absolute cerebral blood volume-cerebral blood flow relationship during visual stimulation in healthy humans.

PubMed

Ciris, Pelin Aksit; Qiu, Maolin; Constable, R Todd

2014-09-01

The relationship between cerebral blood volume (CBV) and cerebral blood flow (CBF) underlies blood oxygenation level-dependent functional MRI signal. This study investigates the potential for improved characterization of the CBV-CBF relationship in humans, and examines sex effects as well as spatial variations in the CBV-CBF relationship. Healthy subjects were imaged noninvasively at rest and during visual stimulation, constituting the first MRI measurement of the absolute CBV-CBF relationship in humans with complete coverage of the functional areas of interest. CBV and CBF estimates were consistent with the literature, and their relationship varied both spatially and with sex. In a region of interest with stimulus-induced activation in CBV and CBF at a significance level of the P < 0.05, a power function fit resulted in CBV = 2.1 CBF(0.32) across all subjects, CBV = 0.8 CBF(0.51) in females and CBV = 4.4 CBF(0.15) in males. Exponents decreased in both sexes as ROIs were expanded to include less significantly activated regions. Consideration for potential sex-related differences, as well as regional variations under a range of physiological states, may reconcile some of the variation across literature and advance our understanding of the underlying cerebrovascular physiology. Copyright © 2013 Wiley Periodicals, Inc.

Cerebral versus systemic hemodynamics during graded orthostatic stress in humans

NASA Technical Reports Server (NTRS)

Levine, B. D.; Giller, C. A.; Lane, L. D.; Buckey, J. C.; Blomqvist, C. G.

1994-01-01

BACKGROUND: Orthostatic syncope is usually attributed to cerebral hypoperfusion secondary to systemic hemodynamic collapse. Recent research in patients with neurocardiogenic syncope has suggested that cerebral vasoconstriction may occur during orthostatic hypotension, compromising cerebral autoregulation and possibly contributing to the loss of consciousness. However, the regulation of cerebral blood flow (CBF) in such patients may be quite different from that of healthy individuals, particularly when assessed during the rapidly changing hemodynamic conditions associated with neurocardiogenic syncope. To be able to interpret the pathophysiological significance of these observations, a clear understanding of the normal responses of the cerebral circulation to orthostatic stress must be obtained, particularly in the context of the known changes in systemic and regional distributions of blood flow and vascular resistance during orthostasis. Therefore, the specific aim of this study was to examine the changes that occur in the cerebral circulation during graded reductions in central blood volume in the absence of systemic hypotension in healthy humans. We hypothesized that cerebral vasoconstriction would occur and CBF would decrease due to activation of the sympathetic nervous system. We further hypothesized, however, that the magnitude of this change would be small compared with changes in systemic or skeletal muscle vascular resistance in healthy subjects with intact autoregulation and would be unlikely to cause syncope without concomitant hypotension. METHODS AND RESULTS: To test this hypothesis, we studied 13 healthy men (age, 27 +/- 7 years) during progressive lower body negative pressure (LBNP). We measured systemic flow (Qc is cardiac output; C2H2 rebreathing), regional forearm flow (FBF; venous occlusion plethysmography), and blood pressure (BP; Finapres) and calculated systemic (SVR) and forearm (FVR) vascular resistances. Changes in brain blood flow were

Detection of cerebral ischemia using the power spectrum of the pulse wave measured by near-infrared spectroscopy.

PubMed

Ebihara, Akira; Tanaka, Yuichi; Konno, Takehiko; Kawasaki, Shingo; Fujiwara, Michiyuki; Watanabe, Eiju

2013-10-01

The diagnosis and medical treatment of cerebral ischemia are becoming more important due to the increase in the prevalence of cerebrovascular disease. However, conventional methods of evaluating cerebral perfusion have several drawbacks: they are invasive, require physical restraint, and the equipment is not portable, which makes repeated measurements at the bedside difficult. An alternative method is developed using near-infrared spectroscopy (NIRS). NIRS signals are measured at 44 positions (22 on each side) on the fronto-temporal areas in 20 patients with cerebral ischemia. In order to extract the pulse-wave component, the raw total hemoglobin data recorded from each position are band-pass filtered (0.8 to 2.0 Hz) and subjected to a fast Fourier transform to obtain the power spectrum of the pulse wave. The ischemic region is determined by single-photon emission computed tomography. The pulse-wave power in the ischemic region is compared with that in the symmetrical region on the contralateral side. In 17 cases (85%), the pulse-wave power on the ischemic side is significantly lower than that on the contralateral side, which indicates that the transmission of the pulse wave is attenuated in the region with reduced blood flow. Pulse-wave power might be useful as a noninvasive marker of cerebral ischemia.

Effects of hyperglycemia and effects of ketosis on cerebral perfusion, cerebral water distribution, and cerebral metabolism.

PubMed

Glaser, Nicole; Ngo, Catherine; Anderson, Steven; Yuen, Natalie; Trifu, Alexandra; O'Donnell, Martha

2012-07-01

Diabetic ketoacidosis (DKA) may cause brain injuries in children. The mechanisms responsible are difficult to elucidate because DKA involves multiple metabolic derangements. We aimed to determine the independent effects of hyperglycemia and ketosis on cerebral metabolism, blood flow, and water distribution. We used magnetic resonance spectroscopy to measure ratios of cerebral metabolites (ATP to inorganic phosphate [Pi], phosphocreatine [PCr] to Pi, N-acetyl aspartate [NAA] to creatine [Cr], and lactate to Cr) and diffusion-weighted imaging and perfusion-weighted imaging to assess cerebral water distribution (apparent diffusion coefficient [ADC] values) and cerebral blood flow (CBF) in three groups of juvenile rats (hyperglycemic, ketotic, and normal control). ATP-to-Pi ratio was reduced in both hyperglycemic and ketotic rats in comparison with controls. PCr-to-Pi ratio was reduced in the ketotic group, and there was a trend toward reduction in the hyperglycemic group. No significant differences were observed in NAA-to-Cr or lactate-to-Cr ratio. Cortical ADC was reduced in both groups (indicating brain cell swelling). Cortical CBF was also reduced in both groups. We conclude that both hyperglycemia and ketosis independently cause reductions in cerebral high-energy phosphates, CBF, and cortical ADC values. These effects may play a role in the pathophysiology of DKA-related brain injury.

Effect of age on cerebral blood flow during hypothermic cardiopulmonary bypass

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brusino, F.G.; Reves, J.G.; Smith, L.R.

1989-04-01

Cerebral blood flow was measured in 20 patients by xenon 133 clearance methodology during nonpulsatile hypothermic cardiopulmonary bypass to determine the effect of age on regional cerebral blood flow during these conditions. Measurements of cerebral blood flow at varying perfusion pressures were made in patients arbitrarily divided into two age groups at nearly identical nasopharyngeal temperature, hematocrit value, and carbon dioxide tension and with equal cardiopulmonary bypass flows of 1.6 L/min/m2. The range of mean arterial pressure was 30 to 110 mm Hg for group I (less than or equal to 50 years of age) and 20 to 90 mmmore » Hg for group II (greater than or equal to 65 years of age). There was no significant difference (p = 0.32) between the mean arterial pressure in group I (54 +/- 28 mm Hg) and that in group II (43 +/- 21 mm Hg). The range of cerebral blood flow was 14.8 to 29.2 ml/100 gm/min for group I and 13.8 to 37.5 ml/100 gm/min for group II. There was no significant difference (p = 0.37) between the mean cerebral blood flow in group I (21.5 +/- 4.6 ml/100 gm/min) and group II (24.3 +/- 8.1 ml/100 gm/min). There was a poor correlation between mean arterial pressure and cerebral blood flow in both groups: group I, r = 0.16 (p = 0.67); group II, r = 0.5 (p = 0.12). In 12 patients, a second cerebral blood flow measurements was taken to determine the effect of mean arterial pressure on cerebral blood flow in the individual patient. Changes in mean arterial pressure did not correlate with changes in cerebral blood flow (p less than 0.90). We conclude that age does not alter cerebral blood flow and that cerebral blood flow autoregulation is preserved in elderly patients during nonpulsatile hypothermic cardiopulmonary bypass.« less

Cerebral cortical neurons with activity linked to central neurogenic spontaneous and evoked elevations in cerebral blood flow

NASA Technical Reports Server (NTRS)

Golanov, E. V.; Reis, D. J.

1996-01-01

We recorded neurons in rat cerebral cortex with activity relating to the neurogenic elevations in regional cerebral blood flow (rCBF) coupled to stereotyped bursts of EEG activity, burst-cerebrovascular wave complexes, appearing spontaneously or evoked by electrical stimulation of rostral ventrolateral medulla (RVL) or fastigial nucleus (FN). Of 333 spontaneously active neurons only 15 (5%), in layers 5-6, consistently (P < 0.05, chi-square) increased their activity during the earliest potential of the complex, approximately 1.3 s before the rise of rCBF, and during the minutes-long elevation of rCBF elicited by 10 s of stimulation of RVL or FN. The results indicate the presence of a small population of neurons in deep cortical laminae whose activity correlates with neurogenic elevations of rCBF. These neurons may function to transduce afferent neuronal signals into vasodilation.

Regional Cerebral Blood Flow In Dementia: Receiver-Operating-Characteristic Analysis

NASA Astrophysics Data System (ADS)

Zemcov, Alexander; Barclay, Laurie; Sansone, Joseph; Blass, John P.; Metz, Charles E.

1985-06-01

The coupling of mentation to regional cerebral blood flow (rCBF) has prompted the application of the Xe-133 inhalation method of measuring rCBF in the differential diagnosis of the two most common dementing diseases, Alzheimer's disease and multi-infarct dementia (MID). In this study receiver-operating-characteristic (ROC) curve analysis was used to assess the effectiveness of a 32 detector Xe-133 inhalation system in discriminating between patients with Alzheimer's disease and normal controls, MID patients and normal controls and between patients with Alzheimer's disease and MID. The populations were clinically evaluated as 1) normal (age 63.1 + 13.1, n=23), 2) Alzheimer's disease (age 72.7 + 7.0, n=82), 3) MID (age 76.4 + 7.6, n=27): The mean flow values for all detectors were lowest for the Alzheimer's disease group, larger for the MID group and largest for the normal controls. The dynamic relationship between the correct identifications (true posi-tives) versus incorrect identifications (false positives) per detector for any 2 pairs of clinical groups varies as the cutoff value of flow is changed over the range of experimental blood flow values. Therefore a quantitative characterization of the "decision" or ROC curve (TP vs FP) for each detector and for each pair of clinical groups provides a measure of the overall diagnostic efficacy of the detector. Detectors directed approximately toward the speech, auditory and association cortices were most effective in disciminatinq between each of the dementia groups and the controls. Frontal detectors were diagnostically inefficient. The Xe-133 inhalation system provided virtually no diagnostic power in discriminating between the two forms of dementia, however. Therefore this imaging technology is most useful when assessing the general diagnostic state of dementia (Alz-heimer's disease and MID) from normal cognitive function.

Restoration of Normal Cerebral Oxygen Consumption with Rapamycin Treatment in a Rat Model of Autism-Tuberous Sclerosis.

PubMed

Chi, Oak Z; Wu, Chang-Chih; Liu, Xia; Rah, Kang H; Jacinto, Estela; Weiss, Harvey R

2015-09-01

Tuberous sclerosis (TSC) is associated with autism spectrum disorders and has been linked to metabolic dysfunction and unrestrained signaling of the mammalian target of rapamycin (mTOR). Inhibition of mTOR by rapamycin can mitigate some of the phenotypic abnormalities associated with TSC and autism, but whether this is due to the mTOR-related function in energy metabolism remains to be elucidated. In young Eker rats, an animal model of TSC and autism, which harbors a germ line heterozygous Tsc2 mutation, we previously reported that cerebral oxygen consumption was pronouncedly elevated. Young (4 weeks) male control Long-Evans and Eker rats were divided into control and rapamycin-treated (20 mg/kg once daily for 2 days) animals. Cerebral regional blood flow ((14)C-iodoantipyrine) and O2 consumption (cryomicrospectrophotometry) were determined in isoflurane-anesthetized rats. We found significantly increased basal O2 consumption in the cortex (8.7 ± 1.5 ml O2/min/100 g Eker vs. 2.7 ± 0.2 control), hippocampus, pons and cerebellum. Regional cerebral blood flow and cerebral O2 extractions were also elevated in all brain regions. Rapamycin had no significant effect on O2 consumption in any brain region of the control rats, but significantly reduced consumption in the cortex (4.1 ± 0.3) and all other examined regions of the Eker rats. Phosphorylation of mTOR and S6K1 was similar in the two groups and equally reduced by rapamycin. Thus, a rapamycin-sensitive, mTOR-dependent but S6K1-independent, signal led to enhanced oxidative metabolism in the Eker brain. We found decreased Akt phosphorylation in Eker but not Long-Evans rat brains, suggesting that this may be related to the increased cerebral O2 consumption in the Eker rat. Our findings suggest that rapamycin targeting of Akt to restore normal cerebral metabolism could have therapeutic potential in tuberous sclerosis and autism.

Cerebral near-infrared spectroscopy insensitively detects low cerebral venous oxygen saturations after stage 1 palliation.

PubMed

Rescoe, Erin; Tang, Xiaoqi; Perry, Dorothy Alison; Sleeper, Lynn A; DiNardo, James A; Kussman, Barry D; Kheir, John N

2017-09-01

Measurement of cerebral venous oxyhemoglobin saturation (ScvO 2 ) is considered a gold standard in assessing the adequacy of tissue oxygen delivery (DO 2 ) after the stage 1 palliation (S1P), with SvO 2  <30% often representing severely compromised DO 2 . Regional oxygenation index (rSO 2 ) based on near-infrared resonance spectroscopy (NIRS) frequently is used to screen for compromised DO 2 , although its sensitivity to detect severe abnormalities in SvO 2 is uncertain. ScvO 2 was measured by co-oximetry from the internal jugular vein as clinically indicated in 73 neonates after S1P. These values were compared with cerebral rSO 2 (FORE-SIGHT; CASMED) via mixed effects model linear regression, Bland-Altman analysis, and sensitivity analysis. Because NIRS devices measure a composite of arterial and venous blood, we calculated an rSO 2 -based ScvO 2 designed to remove arterial contamination from the rSO 2 signal: rSO 2 -based ScvO 2  = (rSO 2 - arterial oxygen saturation × 0.3)/0.7. Among 520 time-matched pairs of ScvO 2 and cerebral rSO 2 , the slope of the relationship between rSO 2 and ScvO 2 (after we adjusted for effects of hemoglobin) was 0.37 ± 0.04 with only modest correlation (r 2  = 0.39), and mean bias of +8.26. When ScvO 2 was <30%, cerebral rSO 2 was <30 in less than 1%, <40 less than 1%, and <50 in 45.7% of data points; specificity of rSO 2 in the same range is >99%. Correction of rSO 2 for arterial contamination significantly decreased mean bias (+3.03) and improved the sensitivity of rSO 2 to detect ScvO 2  <30 to 6.5% for rSO 2  <30, 29% for rSO 2  <40, and 77.4% for rSO 2  <50. Cerebral rSO 2 in isolation should not be used to detect low ScvO 2 , because its sensitivity is low, although correction of rSO 2 for arterial contamination may improve sensitivity. Cerebral rSO 2 of 50 or greater should not be considered reassuring, though values below 30 are specific for low ScvO 2 . Copyright © 2017 The American Association for Thoracic

The association of the metalloproteinase-3 gene promoter polymorphisms and the middle cerebral artery stenosis.

PubMed

Fu, Chunli; Xing, Yingqi; Song, Xiaonan

2011-04-01

To investigate the association of single nucleotide polymorphism in the matrix metalloproteinase-3 (MMP3) gene promoter with the susceptibility to the middle cerebral artery stenosis. A case-control study was performed by determining the genotype of MMP3 gene promoter region using polymerase chain reaction-restriction fragment length polymorphism in 119 patients with middle cerebral artery stenosis documented by transcranial Doppler compared to 92 control patients. The frequencies of 5A and 6A alleles in MMP3 promoter region were 16.0 and 84.0% respectively in case group compared to 15.8 and 84.2% in control group with no significant difference between the two groups (P > 0.05). No significant difference was also observed in the distribution of genotypes 5A/5A,5A/6A, and 6A/6A between middle cerebral artery stenosis and control groups. Compared to 5A/5A + 5A/6A genotypes,the 6A/6A genotype did not significantly modify the risk of developing the middle cerebral artery stenosis. The MMP3-1171 dupA promoter polymorphisms are not valuable markers of susceptibility of the middle cerebral artery stenosis in this sample of population studied.

l-arginine and l-NMMA for assessing cerebral endothelial dysfunction in ischaemic cerebrovascular disease: A systematic review.

PubMed

Karlsson, William K; Sørensen, Caspar G; Kruuse, Christina

2017-01-01

Endothelial dysfunction (ED), in particular cerebral ED, may be an essential biomarker for ischaemic cerebrovascular disease. However, there is no consensus on methods to best estimate cerebral ED. In this systematic review, we evaluate the use of l-arginine and N G -monomethyl-l-arginine (l-NMMA) for assessment of cerebral ED. A systematic search of PubMed, EMBASE and the Cochrane Library was done. We included studies investigating cerebrovascular response to l-arginine or l-NMMA in human subjects with vascular risk factors or ischaemic cerebrovascular disease. Seven studies (315 subjects) were eligible according to inclusion and exclusion criteria. Studies investigated the effect of age (n=2), type 2 diabetes mellitus (DM) (n=1), cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) (n=1), leukoaraiosis (n=1), and prior ischaemic stroke or transient ischaemic attack (TIA) (n=2) on cerebral ED. Most studies applied transcranial Doppler to quantify cerebral ED. Endothelium-dependent vasodilatation (EDV) induced by l-arginine was impaired in elderly and subjects with leukoaraiosis, but enhanced in CADASIL patients. Studies including subjects with prior ischaemic stroke or TIA reported both enhanced and impaired EDV to l-arginine. Responses to l-NMMA deviated between subjects with type 2 DM and the elderly. We found only few studies investigating cerebral endothelial responses to l-arginine and l-NMMA in subjects with vascular risk factors or ischaemic cerebrovascular disease. Inconsistencies in results were most likely due to variations in methods and included subject populations. In order to use cerebral ED as a prognostic marker, further studies are required to evaluate the association to cerebrovascular disease. © 2016 John Wiley & Sons Australia, Ltd.

Land Use in LCA: Including Regionally Altered Precipitation to Quantify Ecosystem Damage.

PubMed

Lathuillière, Michael J; Bulle, Cécile; Johnson, Mark S

2016-11-01

The incorporation of soil moisture regenerated by precipitation, or green water, into life cycle assessment has been of growing interest given the global importance of this resource for terrestrial ecosystems and food production. This paper proposes a new impact assessment model to relate land and water use in seasonally dry, semiarid, and arid regions where precipitation and evapotranspiration are closely coupled. We introduce the Precipitation Reduction Potential midpoint impact representing the change in downwind precipitation as a result of a land transformation and occupation activity. Then, our end-point impact model quantifies terrestrial ecosystem damage as a function of precipitation loss using a relationship between woody plant species richness, water and energy regimes. We then apply the midpoint and end-point models to the production of soybean in Southeastern Amazonia which has resulted from the expansion of cropland into tropical forest, with noted effects on local precipitation. Our proposed cause-effect chain represents a complementary approach to previous contributions which have focused on water consumption impacts and/or have represented evapotranspiration as a loss to the water cycle.

Cerebral palsy - resources

MedlinePlus

Resources - cerebral palsy ... The following organizations are good resources for information on cerebral palsy : National Institute of Neurological Disorders and Stroke -- www.ninds.nih.gov/Disorders/Patient-Caregiver-Education/Hope- ...

Progressive Cortical Neuronal Damage and Chronic Hemodynamic Impairment in Atherosclerotic Major Cerebral Artery Disease.

PubMed

Yamauchi, Hiroshi; Kagawa, Shinya; Kishibe, Yoshihiko; Takahashi, Masaaki; Higashi, Tatsuya

2016-06-01

Cross-sectional studies suggest that chronic hemodynamic impairment may cause selective cortical neuronal damage in patients with atherosclerotic internal carotid artery or middle cerebral artery occlusive disease. The purpose of this longitudinal study was to determine whether the progression of cortical neuronal damage, evaluated as a decrease in central benzodiazepine receptors (BZRs), is associated with hemodynamic impairment at baseline or hemodynamic deterioration during follow-up. We evaluated the distribution of BZRs twice using positron emission tomography and (11)C-flumazenil over time in 80 medically treated patients with atherosclerotic internal carotid artery or middle cerebral artery occlusive disease that had no ischemic episodes during follow-up. Using 3D stereotactic surface projections, we quantified abnormal decreases in the BZRs in the cerebral cortex within the middle cerebral artery distribution and correlated changes in the BZR index with the mean hemispheric values of hemodynamic parameters obtained from (15)O gas positron emission tomography. In the hemisphere affected by arterial disease, the BZR index in 40 patients (50%) was increased during follow-up (mean 26±20 months). In multivariable logistic regression analyses, increases in the BZR index were associated with the decreased cerebral blood flow at baseline and an increased oxygen extraction fraction during follow-up. Increases in the oxygen extraction fraction during follow-up were associated with a lack of statin use. In patients with atherosclerotic internal carotid artery or middle cerebral artery disease, the progression of cortical neuronal damage was associated with hemodynamic impairment at baseline and hemodynamic deterioration during follow-up. Statin use may be beneficial against hemodynamic deterioration and therefore neuroprotective. © 2016 American Heart Association, Inc.

Fully distributed absolute blood flow velocity measurement for middle cerebral arteries using Doppler optical coherence tomography

PubMed Central

Qi, Li; Zhu, Jiang; Hancock, Aneeka M.; Dai, Cuixia; Zhang, Xuping; Frostig, Ron D.; Chen, Zhongping

2016-01-01

Doppler optical coherence tomography (DOCT) is considered one of the most promising functional imaging modalities for neuro biology research and has demonstrated the ability to quantify cerebral blood flow velocity at a high accuracy. However, the measurement of total absolute blood flow velocity (BFV) of major cerebral arteries is still a difficult problem since it is related to vessel geometry. In this paper, we present a volumetric vessel reconstruction approach that is capable of measuring the absolute BFV distributed along the entire middle cerebral artery (MCA) within a large field-of-view. The Doppler angle at each point of the MCA, representing the vessel geometry, is derived analytically by localizing the artery from pure DOCT images through vessel segmentation and skeletonization. Our approach could achieve automatic quantification of the fully distributed absolute BFV across different vessel branches. Experiments on rodents using swept-source optical coherence tomography showed that our approach was able to reveal the consequences of permanent MCA occlusion with absolute BFV measurement. PMID:26977365

Fully distributed absolute blood flow velocity measurement for middle cerebral arteries using Doppler optical coherence tomography.

PubMed

Qi, Li; Zhu, Jiang; Hancock, Aneeka M; Dai, Cuixia; Zhang, Xuping; Frostig, Ron D; Chen, Zhongping

2016-02-01

Doppler optical coherence tomography (DOCT) is considered one of the most promising functional imaging modalities for neuro biology research and has demonstrated the ability to quantify cerebral blood flow velocity at a high accuracy. However, the measurement of total absolute blood flow velocity (BFV) of major cerebral arteries is still a difficult problem since it is related to vessel geometry. In this paper, we present a volumetric vessel reconstruction approach that is capable of measuring the absolute BFV distributed along the entire middle cerebral artery (MCA) within a large field-of-view. The Doppler angle at each point of the MCA, representing the vessel geometry, is derived analytically by localizing the artery from pure DOCT images through vessel segmentation and skeletonization. Our approach could achieve automatic quantification of the fully distributed absolute BFV across different vessel branches. Experiments on rodents using swept-source optical coherence tomography showed that our approach was able to reveal the consequences of permanent MCA occlusion with absolute BFV measurement.

The Cerebral Palsy Research Registry: Development and Progress Toward National Collaboration in the United States

PubMed Central

Hurley, Donna S.; Sukal-Moulton, Theresa; Msall, Michael E.; Gaebler-Spira, Deborah; Krosschell, Kristin J.; Dewald, Julius P.

2011-01-01

Cerebral palsy is the most common neurodevelopmental motor disability in children. The condition requires medical, educational, social, and rehabilitative resources throughout the life span. Several countries have developed population-based registries that serve the purpose of prospective longitudinal collection of etiologic, demographic, and functional severity. The United States has not created a comprehensive program to develop such a registry. Barriers have been large population size, poor interinstitution collaboration, and decentralized medical and social systems. The Cerebral Palsy Research Registry was created to fill the gap between population and clinical-based cerebral palsy registries and promote research in the field. This is accomplished by connecting persons with cerebral palsy, as well as their families, to a network of regional researchers. This article describes the development of an expandable cerebral palsy research registry, its current status, and the potential it has to affect families and persons with cerebral palsy in the United States and abroad. PMID:21677201

Gradient adjustment method for better discriminating correlating and non-correlating regions of physiological signals: application to the partitioning of impaired and intact zones of cerebral autoregulation.

PubMed

Addison, Paul S; Antunes, André; Montgomery, Dean; Borg, Ulf R

2017-08-01

Cerebral blood flow (CBF) is regulated over a range of systemic blood pressures by the cerebral autoregulation (CA) control mechanism. This range lies within the lower and upper limits of autoregulation (LLA, ULA), beyond which blood pressure drives CBF, and CA function is considered impaired. A standard method to determine autoregulation limits noninvasively using NIRS technology is via the COx measure: a moving correlation index between mean arterial pressure and regional oxygen saturation. In the intact region, there should be no correlation between these variables whereas in the impaired region, the correlation index should approximate unity. In practice, however, the data may be noisy and/or the intact region may often exhibit a slightly positive relationship. This positive relationship may render traditional autoregulation limit calculations difficult to perform, resulting in the need for manual interpretation of the data using arbitrary thresholds. Further, the underlying mathematics of the technique are asymmetric in terms of the results produced for impaired and intact regions and are, in fact, not computable for the ideal case within the intact region. In this work, we propose a novel gradient adjustment method (GACOx) to enhance the differences in COx values observed in the intact and impaired regions. Results from a porcine model (N = 8) are used to demonstrate that GACOx is successful in determining LLA values where traditional methods fail. It is shown that the derived GACOx indices exhibit a mean difference between the intact/impaired regions of 1.54 ± 0.26 (mean ± SD), compared to 0.14 ± 0.10 for the traditional COx method. The GACOx effectively polarizes the COx data in order to better differentiate the intact and impaired zones and, in doing so, makes the determination of the LLA and ULA points a simpler and more consistent task. The method lends itself to the automation of the robust determination of autoregulation zone limits.

Quantifying renewable groundwater stress with GRACE

NASA Astrophysics Data System (ADS)

Richey, Alexandra S.; Thomas, Brian F.; Lo, Min-Hui; Reager, John T.; Famiglietti, James S.; Voss, Katalyn; Swenson, Sean; Rodell, Matthew

2015-07-01

Groundwater is an increasingly important water supply source globally. Understanding the amount of groundwater used versus the volume available is crucial to evaluate future water availability. We present a groundwater stress assessment to quantify the relationship between groundwater use and availability in the world's 37 largest aquifer systems. We quantify stress according to a ratio of groundwater use to availability, which we call the Renewable Groundwater Stress ratio. The impact of quantifying groundwater use based on nationally reported groundwater withdrawal statistics is compared to a novel approach to quantify use based on remote sensing observations from the Gravity Recovery and Climate Experiment (GRACE) satellite mission. Four characteristic stress regimes are defined: Overstressed, Variable Stress, Human-dominated Stress, and Unstressed. The regimes are a function of the sign of use (positive or negative) and the sign of groundwater availability, defined as mean annual recharge. The ability to mitigate and adapt to stressed conditions, where use exceeds sustainable water availability, is a function of economic capacity and land use patterns. Therefore, we qualitatively explore the relationship between stress and anthropogenic biomes. We find that estimates of groundwater stress based on withdrawal statistics are unable to capture the range of characteristic stress regimes, especially in regions dominated by sparsely populated biome types with limited cropland. GRACE-based estimates of use and stress can holistically quantify the impact of groundwater use on stress, resulting in both greater magnitudes of stress and more variability of stress between regions.

Quantifying renewable groundwater stress with GRACE

PubMed Central

Richey, Alexandra S.; Thomas, Brian F.; Lo, Min‐Hui; Reager, John T.; Voss, Katalyn; Swenson, Sean; Rodell, Matthew

2015-01-01

Abstract Groundwater is an increasingly important water supply source globally. Understanding the amount of groundwater used versus the volume available is crucial to evaluate future water availability. We present a groundwater stress assessment to quantify the relationship between groundwater use and availability in the world's 37 largest aquifer systems. We quantify stress according to a ratio of groundwater use to availability, which we call the Renewable Groundwater Stress ratio. The impact of quantifying groundwater use based on nationally reported groundwater withdrawal statistics is compared to a novel approach to quantify use based on remote sensing observations from the Gravity Recovery and Climate Experiment (GRACE) satellite mission. Four characteristic stress regimes are defined: Overstressed, Variable Stress, Human‐dominated Stress, and Unstressed. The regimes are a function of the sign of use (positive or negative) and the sign of groundwater availability, defined as mean annual recharge. The ability to mitigate and adapt to stressed conditions, where use exceeds sustainable water availability, is a function of economic capacity and land use patterns. Therefore, we qualitatively explore the relationship between stress and anthropogenic biomes. We find that estimates of groundwater stress based on withdrawal statistics are unable to capture the range of characteristic stress regimes, especially in regions dominated by sparsely populated biome types with limited cropland. GRACE‐based estimates of use and stress can holistically quantify the impact of groundwater use on stress, resulting in both greater magnitudes of stress and more variability of stress between regions. PMID:26900185

Cerebral arteriovenous malformation

MedlinePlus

AVM - cerebral; Arteriovenous hemangioma; Stroke - AVM; Hemorrhagic stroke - AVM ... The cause of cerebral AVM is unknown. An AVM occurs when arteries in the brain connect directly to nearby veins without having the ...

Regional brain volumetry and brain function in severely brain-injured patients.

PubMed

Annen, Jitka; Frasso, Gianluca; Crone, Julia Sophia; Heine, Lizette; Di Perri, Carol; Martial, Charlotte; Cassol, Helena; Demertzi, Athena; Naccache, Lionel; Laureys, Steven

2018-04-01

The relationship between residual brain tissue in patients with disorders of consciousness (DOC) and the clinical condition is unclear. This observational study aimed to quantify gray (GM) and white matter (WM) atrophy in states of (altered) consciousness. Structural T1-weighted magnetic resonance images were processed for 102 severely brain-injured and 52 healthy subjects. Regional brain volume was quantified for 158 (sub)cortical regions using Freesurfer. The relationship between regional brain volume and clinical characteristics of patients with DOC and conscious brain-injured patients was assessed using a linear mixed-effects model. Classification of patients with unresponsive wakefulness syndrome (UWS) and minimally conscious state (MCS) using regional volumetric information was performed and compared to classification using cerebral glucose uptake from fluorodeoxyglucose positron emission tomography. For validation, the T1-based classifier was tested on independent datasets. Patients were characterized by smaller regional brain volumes than healthy subjects. Atrophy occurred faster in UWS compared to MCS (GM) and conscious (GM and WM) patients. Classification was successful (misclassification with leave-one-out cross-validation between 2% and 13%) and generalized to the independent data set with an area under the receiver operator curve of 79% (95% confidence interval [CI; 67-91.5]) for GM and 70% (95% CI [55.6-85.4]) for WM. Brain volumetry at the single-subject level reveals that regions in the default mode network and subcortical gray matter regions, as well as white matter regions involved in long range connectivity, are most important to distinguish levels of consciousness. Our findings suggest that changes of brain structure provide information in addition to the assessment of functional neuroimaging and thus should be evaluated as well. Ann Neurol 2018;83:842-853. © 2018 American Neurological Association.

Aging and Cerebral Palsy.

ERIC Educational Resources Information Center

Networker, 1993

1993-01-01

This special edition of "The Networker" contains several articles focusing on aging and cerebral palsy (CP). "Aging and Cerebral Palsy: Pathways to Successful Aging" (Jenny C. Overeynder) reports on the National Invitational Colloquium on Aging and Cerebral Palsy held in April 1993. "Observations from an Observer" (Kathleen K. Barrett) describes…

Cerebral perfusion and oxygenation after the Norwood procedure: comparison of right ventricle-pulmonary artery conduit with modified Blalock-Taussig shunt.

PubMed

Kussman, Barry D; Gauvreau, Kimberlee; DiNardo, James A; Newburger, Jane W; Mackie, Andrew S; Booth, Karen L; del Nido, Pedro J; Roth, Stephen J; Laussen, Peter C

2007-03-01

The proposed physiologic advantage of the modified Norwood procedure using a right ventricle-pulmonary artery conduit to supply pulmonary blood flow, compared with a modified Blalock-Taussig shunt, is reduced runoff from the systemic-to-pulmonary circulation during diastole, resulting in a higher diastolic blood pressure and improved systemic perfusion. We hypothesized that the modified Norwood procedure is associated with improved cerebral perfusion and oxygenation. Transcranial Doppler sonography and near-infrared spectroscopy were performed in neonates undergoing the Norwood procedure with either a modified Blalock-Taussig shunt (n = 14) or right ventricle-pulmonary artery conduit (n = 13). Diastolic blood pressure was significantly higher in the right ventricle-pulmonary artery group at 6 hours after bypass (46 +/- 7 vs 40 +/- 4 mm Hg; P = .03), on postoperative day 1 (45 +/- 6 vs 37 +/- 5 mm Hg; P = .002), and on postoperative day 2 (46 +/- 7 vs 37 +/- 4 mm Hg; P = .001). Cerebral diastolic blood flow velocity did not differ significantly between groups at any time point or over time, but cerebral systolic blood flow velocity was higher over time in the Blalock-Taussig group (P = .01). No significant differences in regional cerebral oxygen saturation were found between groups at baseline or after bypass. Blood flow velocities and cerebral oxygen saturation did not differ significantly according to use of regional low-flow perfusion. The higher diastolic blood pressure after the modified Norwood procedure is not associated with higher cerebral blood flow velocities or regional cerebral oxygen saturation. This may imply an equal vulnerability to the cerebral injury associated with hemodynamic instability in the early postoperative period.

Influence of anesthesia on cerebral blood flow, cerebral metabolic rate, and brain functional connectivity.

PubMed

Bonhomme, Vincent; Boveroux, Pierre; Hans, Pol; Brichant, Jean François; Vanhaudenhuyse, Audrey; Boly, Melanie; Laureys, Steven

2011-10-01

To describe recent studies exploring brain function under the influence of hypnotic anesthetic agents, and their implications on the understanding of consciousness physiology and anesthesia-induced alteration of consciousness. Cerebral cortex is the primary target of the hypnotic effect of anesthetic agents, and higher-order association areas are more sensitive to this effect than lower-order processing regions. Increasing concentration of anesthetic agents progressively attenuates connectivity in the consciousness networks, while connectivity in lower-order sensory and motor networks is preserved. Alteration of thalamic sub-cortical regulation could compromise the cortical integration of information despite preserved thalamic activation by external stimuli. At concentrations producing unresponsiveness, the activity of consciousness networks becomes anticorrelated with thalamic activity, while connectivity in lower-order sensory networks persists, although with cross-modal interaction alterations. Accumulating evidence suggests that hypnotic anesthetic agents disrupt large-scale cerebral connectivity. This would result in an inability of the brain to generate and integrate information, while external sensory information is still processed at a lower order of complexity.

Improving 1H MRSI measurement of cerebral lactate for clinical applications

PubMed Central

Corrigan, Neva M.; Richards, Todd L.; Friedman, Seth D.; Petropoulos, Helen; Dager, Stephen R.

2010-01-01

Accurate measurement of cerebral lactate is critical to the understanding of brain function for psychiatric disorders such as panic disorder and bipolar disorder as well as mitochondrial dysfunction. Proton magnetic spectroscopic imaging (MRSI) techniques can be used to study lactate in vivo; however, accurate measurement of cerebral lactate, which is normally at low basal abundance, can be challenging. In this study, regional lactate measurements obtained with two different MRSI analytic approaches were evaluated using proton echo-planar spectroscopic imaging (PEPSI) data from 18 healthy adults participating in an in vivo sodium lactate infusion study. The results demonstrate that averaging data within a region of interest (ROI) before spectral fitting with LCModel results in significantly improved lactate measurement as compared to averaging chemical concentrations derived from the fitting of individual voxels in the ROI. Simulation results that confirm this finding are also presented. This study additionally outlines an atlas-based approach for the systematic computation of regional distributions of chemical concentrations in large MRSI data sets. PMID:20236806

Positive affect predicts cerebral glucose metabolism in late middle-aged adults

PubMed Central

Nicholas, Christopher R.; Hoscheidt, Siobhan M.; Clark, Lindsay R.; Racine, Annie M.; Berman, Sara E.; Koscik, Rebecca L.; Maritza Dowling, N.; Asthana, Sanjay; Christian, Bradley T.; Sager, Mark A.

2017-01-01

Abstract Positive affect is associated with a number of health benefits; however, few studies have examined the relationship between positive affect and cerebral glucose metabolism, a key energy source for neuronal function and a possible index of brain health. We sought to determine if positive affect was associated with cerebral glucose metabolism in late middle-aged adults (n = 133). Participants completed the positive affect subscale of the Center for Epidemiological Studies Depression Scale at two time points over a two-year period and underwent 18F-fluorodeoxyglucose-positron emission tomography scanning. After controlling for age, sex, perceived health status, depressive symptoms, anti-depressant use, family history of Alzheimer’s disease, APOE ε4 status and interval between visits, positive affect was associated with greater cerebral glucose metabolism across para-/limbic, frontal, temporal and parietal regions. Our findings provide evidence that positive affect in late midlife is associated with greater brain health in regions involved in affective processing and also known to be susceptible to early neuropathological processes. The current findings may have implications for interventions aimed at increasing positive affect to attenuate early neuropathological changes in at-risk individuals. PMID:28402542

[Raman spectra of monkey cerebral cortex tissue].

PubMed

Zhu, Ji-chun; Guo, Jian-yu; Cai, Wei-ying; Wang, Zu-geng; Sun, Zhen-rong

2010-01-01

Monkey cerebral cortex, an important part in the brain to control action and thought activities, is mainly composed of grey matter and nerve cell. In the present paper, the in situ Raman spectra of the cerebral cortex of the birth, teenage and aged monkeys were achieved for the first time. The results show that the Raman spectra for the different age monkey cerebral cortex exhibit most obvious changes in the regions of 1000-1400 and 2800-3000 cm(-1). With monkey growing up, the relative intensities of the Raman bands at 1313 and 2885 cm(-1) mainly assigned to CH2 chain vibrational mode of lipid become stronger and stronger whereas the relative intensities of the Raman bands at 1338 and 2932 cm(-1) mainly assigned to CH3 chain vibrational mode of protein become weaker and weaker. In addition, the two new Raman bands at 1296 and 2850 cm(-1) are only observed in the aged monkey cerebral cortex, therefore, the two bands can be considered as a character or "marker" to differentiate the caducity degree with monkey growth In order to further explore the changes, the relative intensity ratios of the Raman band at 1313 cm(-1) to that at 1338 cm(-1) and the Raman band at 2885 cm(-1) to that at 2 932 cm(-1), I1313/I1338 and I2885/I2932, which are the lipid-to-protein ratios, are introduced to denote the degree of the lipid content. The results show that the relative intensity ratios increase significantly with monkey growth, namely, the lipid content in the cerebral cortex increases greatly with monkey growth. So, the authors can deduce that the overmuch lipid is an important cause to induce the caducity. Therefore, the results will be a powerful assistance and valuable parameter to study the order of life growth and diagnose diseases.

Revealing the cerebral regions and networks mediating vulnerability to depression: oxidative metabolism mapping of rat brain.

PubMed

Harro, Jaanus; Kanarik, Margus; Kaart, Tanel; Matrov, Denis; Kõiv, Kadri; Mällo, Tanel; Del Río, Joaquin; Tordera, Rosa M; Ramirez, Maria J

2014-07-01

The large variety of available animal models has revealed much on the neurobiology of depression, but each model appears as specific to a significant extent, and distinction between stress response, pathogenesis of depression and underlying vulnerability is difficult to make. Evidence from epidemiological studies suggests that depression occurs in biologically predisposed subjects under impact of adverse life events. We applied the diathesis-stress concept to reveal brain regions and functional networks that mediate vulnerability to depression and response to chronic stress by collapsing data on cerebral long term neuronal activity as measured by cytochrome c oxidase histochemistry in distinct animal models. Rats were rendered vulnerable to depression either by partial serotonergic lesion or by maternal deprivation, or selected for a vulnerable phenotype (low positive affect, low novelty-related activity or high hedonic response). Environmental adversity was brought about by applying chronic variable stress or chronic social defeat. Several brain regions, most significantly median raphe, habenula, retrosplenial cortex and reticular thalamus, were universally implicated in long-term metabolic stress response, vulnerability to depression, or both. Vulnerability was associated with higher oxidative metabolism levels as compared to resilience to chronic stress. Chronic stress, in contrast, had three distinct patterns of effect on oxidative metabolism in vulnerable vs. resilient animals. In general, associations between regional activities in several brain circuits were strongest in vulnerable animals, and chronic stress disrupted this interrelatedness. These findings highlight networks that underlie resilience to stress, and the distinct response to stress that occurs in vulnerable subjects. Copyright © 2014 Elsevier B.V. All rights reserved.

[Cerebral protection].

PubMed

Cattaneo, A D

1993-09-01

Cerebral protection means prevention of cerebral neuronal damage. Severe brain damage extinguishes the very "human" functions such as speech, consciousness, intellectual capacity, and emotional integrity. Many pathologic conditions may inflict injuries to the brain, therefore the protection and salvage of cerebral neuronal function must be the top priorities in the care of critically ill patients. Brain tissue has unusually high energy requirements, its stores of energy metabolites are small and, as a result, the brain is totally dependent on a continuous supply of substrates and oxygen, via the circulation. In complete global ischemia (cardiac arrest) reperfusion is characterized by an immediate reactive hyperemia followed within 20-30 min by a delayed hypoperfusion state. It has been postulated that the latter contributes to the ultimate neurologic outcome. In focal ischemia (stroke) the primary focus of necrosis is encircled by an area (ischemic penumbra) that is underperfused and contains neurotoxic substances such as free radicals, prostaglandins, calcium, and excitatory neurotransmitters. The variety of therapeutic effort that have addressed the question of protecting the brain reflects their limited success. 1) Barbiturates. After an initial enthusiastic endorsement by many clinicians and years of vigorous controversy, it can now be unequivocally stated that there is no place for barbiturate therapy following resuscitation from cardiac arrest. One presumed explanation for this negative statement is that cerebral metabolic suppression by barbiturates (and other anesthetics) is impossible in the absence of an active EEG. Conversely, in the event of incomplete ischemia EEG activity in usually present (albeit altered) and metabolic suppression and hence possibly protection can be induced with barbiturates. Indeed, most of the animal studies led to a number of recommendations for barbiturate therapy in man for incomplete ischemia. 2) Isoflurane. From a cerebral

Lexical factors and cerebral regions influencing verbal fluency performance in MCI.

PubMed

Clark, D G; Wadley, V G; Kapur, P; DeRamus, T P; Singletary, B; Nicholas, A P; Blanton, P D; Lokken, K; Deshpande, H; Marson, D; Deutsch, G

2014-02-01

nouns score in the left inferior frontal gyrus, but for letter A, letter S, and a composite FAS score in the right inferior frontal gyrus. These regressions also revealed a lateralized association of the left subcortical nuclei with all letter fluency scores and fruits and vegetables fluency, and an association of the right lower temporal ROI with letter A, FAS, and verb fluency. Gray matter volume in several bihemispheric ROIs (left dorsal frontal, right lower temporal, right occipital, and bilateral mesial temporal) mediated the relationship between cognitive impairment and fluency for fruits and vegetables. Gray matter volume in the right lower temporal ROI mediated the relationship between cognitive impairment and five fluency raw scores (animals, fruits and vegetables, tools, verbs, and the composite nouns score). Semantic memory exerts the strongest influence on word adjacency in letter fluency as well as semantic verbal fluency tasks. Orthography is a stronger influence than pronunciation. All types of fluency task raw scores (letter, noun, and verb) correlate with cerebral regions known to support verbal or nonverbal semantic memory. The findings emphasize the contribution of right hemisphere regions to fluency task performance, particularly for verb and letter fluency. The relationship between diagnosis and semantic fluency performance is mediated by semantic similarity of words and by gray matter volume in the right lower temporal region. Published by Elsevier Ltd.

Female exposure to high G: effects of simulated combat sorties on cerebral and arterial O2 saturation.

PubMed

Tripp, L D; Chelette, T; Savul, S; Widman, R A

1998-09-01

One of the key factors in maintaining optimal cognitive performance in the high-G environment is the adequate delivery of oxygen to the cerebral tissue. As eye-level blood pressure is compromised at 22 mmHg x G(-1), perfusion to the peripheral cerebral tissues (cerebral cortex) may not be adequate to support the mental demands of flight. This study measured the effect of closed-loop flight simulations (3 min) on cerebral oxygen saturation changes (rSO2), arterial oxygen saturation (SAO2), and heart rate (HR), in both rested (8 h of rest) and sleepless (24 h without sleep) conditions. Subjects (16; 8 males and 8 females) were subjected to G-exposures via closed-loop flight simulations in a series of four 3-min sorties flown by subjects on the Dynamic Environment Simulator (centrifuge) in either a rested or a sleepless state. Prior to the centrifuge flight, subjects were instrumented with sensors for measurement of arterial oxygen saturation (SAO2) and regional cerebral tissue oxygenation (rSO2). Subjects wore the standard flight suit, boots, CSU-13B/P anti-G suit, and the COMBAT EDGE positive-pressure breathing for G-protection system. Significant changes in cerebral and arterial oxygen saturation were observed within groups when comparing pretest baselines and minimum values during the test and pre- and post-G rSO2, SAO2, and HR in both the rested and sleepless state, (p # 0.01), respectively, for each group. Comparisons between groups showed women to have significantly smaller regional cerebral cortex oxygen decreases than men (p # 0.01). No significant changes in SAO2, however, were observed between groups. Both men and women showed a slow recovery of rSO2 values to the prebaseline levels. Sleeplessness had no effect on the rSO2, SAO2, and HR compared with the rested condition. During acceleration, regional cerebral tissue oxygen decreased 13% in men compared with 9% in women. The recovery of cerebral tissue oxygen levels to prebaseline values was retarded

Non-invasive assessment of cerebral oxygen metabolism following surgery of congenital heart disease.

PubMed

Neunhoeffer, Felix; Sandner, Katharina; Wiest, Milena; Haller, Christoph; Renk, Hanna; Kumpf, Matthias; Schlensak, Christian; Hofbeck, Michael

2017-07-01

Cerebral protection is a major issue in the treatment of infants with complex congenital heart disease. We tested a new device combining tissue spectrometry and laser Doppler flowmetry for non-invasive determination of cerebral oxygen metabolism following cardiac surgery in infants. We prospectively measured regional cerebral oxygen saturation cSO 2 and microperfusion (rcFlow) in 43 infants 12-24 h following corrective ( n  = 30) or palliative surgery ( n  = 13) of congenital heart defects. For comparison, cerebral blood flow (CBF) was determined by colour duplex sonography of the extracranial cerebral arteries. Cerebral fractional tissue oxygen extraction, approximated cerebral metabolic rate of oxygen (aCMRO 2 ) and cerebral metabolic rate of oxygen (CMRO 2 ) were calculated. cSO 2 was lower [54.6% (35.7-64.0) vs 59.7% (44.5-81.7); P  < 0.01] after neonatal palliation, while rcFlow [69.7 AU (42.5-165.3) vs 77.0 AU (41.2-168.1); P  = 0.06] and cerebral fractional tissue oxygen extraction [0.34 (0.24-0.82) vs 0.38 (0.17-0.55); P  = 0.63] showed a trend towards lower values. We found a positive correlation between aCMRO 2 and CMRO 2 ( r  = 0.27; P  = 0.03). aCMRO 2 was significantly lower after neonatal palliation [4.0 AU (2.1-6.3) vs 4.9 AU (2.2-15.6); P  = 0.02]. According to our experience, combined photospectrometry and laser Doppler flowmetry enable non-invasive assessment of cerebral oxygen metabolism. The method promises new insights into perioperative cerebral perfusion following palliation or corrective surgery in infancy. © The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Sleep-Wake Differences in Relative Regional Cerebral Metabolic Rate for Glucose among Patients with Insomnia Compared with Good Sleepers.

PubMed

Kay, Daniel B; Karim, Helmet T; Soehner, Adriane M; Hasler, Brant P; Wilckens, Kristine A; James, Jeffrey A; Aizenstein, Howard J; Price, Julie C; Rosario, Bedda L; Kupfer, David J; Germain, Anne; Hall, Martica H; Franzen, Peter L; Nofzinger, Eric A; Buysse, Daniel J

2016-10-01

The neurobiological mechanisms of insomnia may involve altered patterns of activation across sleep-wake states in brain regions associated with cognition, self-referential processes, affect, and sleep-wake promotion. The objective of this study was to compare relative regional cerebral metabolic rate for glucose (rCMR glc ) in these brain regions across wake and nonrapid eye movement (NREM) sleep states in patients with primary insomnia (PI) and good sleeper controls (GS). Participants included 44 PI and 40 GS matched for age (mean = 37 y old, range 21-60), sex, and race. We conducted [ 18 F]fluoro-2-deoxy-D-glucose positron emission tomography scans in PI and GS during both morning wakefulness and NREM sleep at night. Repeated measures analysis of variance was used to test for group (PI vs. GS) by state (wake vs. NREM sleep) interactions in relative rCMR glc . Significant group-by-state interactions in relative rCMR glc were found in the precuneus/posterior cingulate cortex, left middle frontal gyrus, left inferior/superior parietal lobules, left lingual/fusiform/occipital gyri, and right lingual gyrus. All clusters were significant at P corrected < 0.05. Insomnia was characterized by regional alterations in relative glucose metabolism across NREM sleep and wakefulness. Significant group-by-state interactions in relative rCMR glc suggest that insomnia is associated with impaired disengagement of brain regions involved in cognition (left frontoparietal), self-referential processes (precuneus/posterior cingulate), and affect (left middle frontal, fusiform/lingual gyri) during NREM sleep, or alternatively, to impaired engagement of these regions during wakefulness. © 2016 Associated Professional Sleep Societies, LLC.

Can Structural MRI Indices of Cerebral Integrity Track Cognitive Trends in Executive Control Function During Normal Maturation and Adulthood?

PubMed Central

Kochunov, Peter; Robin, Don A.; Royall, Don R.; Coyle, Thomas; Lancaster, Jack; Kochunov, Valeria; Schlosser, Anita E.; Fox, Peter T.

2009-01-01

We explored the relationship between structural neuroimaging-based indices of cerebral integrity and executive control function (ECF) in two groups of healthy subjects: A maturing group (33 subjects; 19–29 years) and a senescing group (38 adults; 30–90 years). ECF was assessed using the Executive Interview (EXIT) battery. Cortical indices of cerebral integrity included GM thickness, intergyral span, and sulcal span, each measured for five cortical regions per hemisphere. Subcortical indices included fractional anisotropy (FA), measured using track-based-spatial-statistics (TBSS), and the volume of T2-hyperintense WM (HWM). In the maturing group, no significant relationships between neuroanatomical changes and ECF were found; however, there were hints that late-term maturation of cerebral WM influenced variability in ECF. In the senescing group, the decline in ECF corresponded to atrophic changes in cerebral WM (sulcal and intergyral span) primarily in the superior frontal and anterior cingulate regions. A large fraction of the variability in ECF (62%) can be explained by variability in the structural indices from these two regions. PMID:19067326

Paradoxical reduction of cerebral blood flow after acetazolamide loading: a hemodynamic and metabolic study with (15)O PET.

PubMed

Watabe, Tadashi; Shimosegawa, Eku; Kato, Hiroki; Isohashi, Kayako; Ishibashi, Mana; Tatsumi, Mitsuaki; Kitagawa, Kazuo; Fujinaka, Toshiyuki; Yoshimine, Toshiki; Hatazawa, Jun

2014-10-01

Paradoxical reduction of cerebral blood flow (CBF) after administration of the vasodilator acetazolamide is the most severe stage of cerebrovascular reactivity failure and is often associated with an increased oxygen extraction fraction (OEF). In this study, we aimed to reveal the mechanism underlying this phenomenon by focusing on the ratio of CBF to cerebral blood volume (CBV) as a marker of regional cerebral perfusion pressure (CPP). In 37 patients with unilateral internal carotid or middle cerebral arterial (MCA) steno-occlusive disease and 8 normal controls, the baseline CBF (CBF(b)), CBV, OEF, cerebral oxygen metabolic rate (CMRO2), and CBF after acetazolamide loading in the anterior and posterior MCA territories were measured by (15)O positron emission tomography. Paradoxical CBF reduction was found in 28 of 74 regions (18 of 37 patients) in the ipsilateral hemisphere. High CBF(b) (> 47.6 mL/100 mL/min, n = 7) was associated with normal CBF(b)/CBV, increased CBV, decreased OEF, and normal CMRO2. Low CBF(b) (< 31.8 mL/100 mL/min, n = 9) was associated with decreased CBF(b)/CBV, increased CBV, increased OEF, and decreased CMRO2. These findings demonstrated that paradoxical CBF reduction is not always associated with reduction of CPP, but partly includes high-CBF(b) regions with normal CPP, which has not been described in previous studies.

Glucose administration after traumatic brain injury improves cerebral metabolism and reduces secondary neuronal injury

PubMed Central

Moro, Nobuhiro; Ghavim, Sima; Harris, Neil G.; Hovda, David A.; Sutton, Richard L.

2013-01-01

Clinical studies have indicated an association between acute hyperglycemia and poor outcomes in patients with traumatic brain injury (TBI), although optimal blood glucose levels needed to maximize outcomes for these patients’ remains under investigation. Previous results from experimental animal models suggest that post-TBI hyperglycemia may be harmful, neutral, or beneficial. The current studies determined the effects of single or multiple episodes of acute hyperglycemia on cerebral glucose metabolism and neuronal injury in a rodent model of unilateral controlled cortical impact (CCI) injury. In Experiment 1, a single episode of hyperglycemia (50% glucose at 2 g/kg, i.p.) initiated immediately after CCI was found to significantly attenuate a TBI-induced depression of glucose metabolism in cerebral cortex (4 of 6 regions) and subcortical regions (2 of 7) as well as to significantly reduce the number of dead/dying neurons in cortex and hippocampus at 24 h post-CCI. Experiment 2 examined effects of more prolonged and intermittent hyperglycemia induced by glucose administrations (2 g/kg, i.p.) at 0, 1, 3 and 6 h post-CCI. The latter study also found significantly improved cerebral metabolism (in 3 of 6 cortical and 3 of 7 subcortical regions) and significant neuroprotection in cortex and hippocampus 1 day after CCI and glucose administration. These results indicate that acute episodes of post-TBI hyperglycemia can be beneficial and are consistent with other recent studies showing benefits of providing exogenous energy substrates during periods of increased cerebral metabolic demand. PMID:23994447

Brain-derived neurotrophic factor inhibits glucose intolerance after cerebral ischemia

PubMed Central

Shu, Xiaoliang; Zhang, Yongsheng; Xu, Han; Kang, Kai; Cai, Donglian

2013-01-01

Brain-derived neurotrophic factor is associated with the insulin signaling pathway and glucose tabolism. We hypothesized that expression of brain-derived neurotrophic factor and its receptor may be involved in glucose intolerance following ischemic stress. To verify this hypothesis, this study aimed to observe the changes in brain-derived neurotrophic factor and tyrosine kinase B receptor expression in glucose metabolism-associated regions following cerebral ischemic stress in mice. At day 1 after middle cerebral artery occlusion, the expression levels of brain-derived neurotrophic factor were significantly decreased in the ischemic cortex, hypothalamus, liver, skeletal muscle, and pancreas. The expression levels of tyrosine kinase B receptor were decreased in the hypothalamus and liver, and increased in the skeletal muscle and pancreas, but remained unchanged in the cortex. Intrahypothalamic administration of brain-derived neurotrophic factor (40 ng) suppressed the decrease in insulin receptor and tyrosine-phosphorylated insulin receptor expression in the liver and skeletal muscle, and inhibited the overexpression of gluconeogenesis-associated phosphoenolpyruvate carboxykinase and glucose-6-phosphatase in the liver of cerebral ischemic mice. However, serum insulin levels remained unchanged. Our experimental findings indicate that brain-derived neurotrophic factor can promote glucose metabolism, reduce gluconeogenesis, and decrease blood glucose levels after cerebral ischemic stress. The low expression of brain-derived neurotrophic factor following cerebral ischemia may be involved in the development of glucose intolerance. PMID:25206547

Cerebral ischemia and reperfusion increases the heterogeneity of local oxygen supply/consumption balance.

PubMed

Weiss, Harvey R; Grayson, Jeremy; Liu, Xia; Barsoum, Sylviana; Shah, Harsh; Chi, Oak Z

2013-09-01

After cerebral vessel blockage, local blood flow and O2 consumption becomes lower and oxygen extraction increases. With reperfusion, blood flow is partially restored. We examined the effects of ischemia-reperfusion on the heterogeneity of local venous oxygen saturation in rats in order to determine the pattern of microregional O2 supply/consumption balance in reperfusion. The middle cerebral artery was blocked for 1 hour using the internal carotid approach in 1 group (n=9) and was then reperfused for 2 hours in another group (n=9) of isoflurane-anesthetized rats. Regional cerebral blood flow was determined using a C(14)-iodoantipyrine autoradiographic technique. Regional small vessel arterial and venous oxygen saturations were determined microspectrophotometrically. After 1 hour of ischemia, local cerebral blood flow (92±10 versus 50±10 mL/min per 100 g) and O2 consumption (4.5±0.6 versus 2.7±0.5 mL O2/min per 100 g) decreased compared with the contralateral cortex. Oxygen extraction increased (4.7±0.2 versus 5.4±0.3 mL O2/100 mL) and the variation in small vein (20-60 μm) O2 saturation as determined by its coefficient of variation (=100×SD/mean) increased (5.5 versus 10.5). With 2 hours of reperfusion, the blood flow decrement was reduced and O2 consumption returned to the value in the contralateral cortex. Oxygen extraction remained elevated in the ischemic-reperfused area and the coefficient of variation of small vein O2 saturation increased further (17.3). These data indicated continued reduction of O2 supply/consumption balance with reperfusion. They also demonstrated many small regions of low oxygenation within the reperfused cortical region.

Klotho upregulation contributes to the neuroprotection of ligustilide against cerebral ischemic injury in mice.

PubMed

Long, Fang-Yi; Shi, Meng-Qi; Zhou, Hong-Jing; Liu, Dong-Ling; Sang, Na; Du, Jun-Rong

2018-02-05

Klotho, an aging-suppressor gene, encodes a protein that potentially acts as a neuroprotective factor. Our previous studies showed that ligustilide minimizes the cognitive dysfunction and brain damage induced by cerebral ischemia; however, the underlying mechanisms remain unclear. This study aims to investigate whether klotho is involved in the protective effects of ligustilide against cerebral ischemic injury in mice. Cerebral ischemia was induced by bilateral common carotid arterial occlusion. Neurobehavioral tests as well as Nissl and Fluoro-Jade B staining were used to evaluate the protective effects of ligustilide in cerebral ischemia, and Western blotting and ELISA approaches were used to investigate the underlying mechanisms. Administration of ligustilide prevented the development of neurological deficits and reduced neuronal loss in the hippocampal CA1 region and the caudate putamen after cerebral ischemia. The protective effects were associated with inhibition of the RIG-I/NF-κB p65 and Akt/FoxO1 pathways and with prevention of inflammation and oxidative stress in the brain. Further, downregulation of klotho could attenuate the neuroprotection of ligustilide against cerebral ischemic injury. Ligustilide exerted neuroprotective effects in mice after cerebral ischemia by regulating anti-inflammatory and anti-oxidant signaling pathways. Furthermore, klotho upregulation contributes to the neuroprotection of LIG against cerebral ischemic injury. These results indicated that ligustilide may be a promising therapeutic agent for the treatment of cerebral ischemia. Copyright © 2017 Elsevier B.V. All rights reserved.

In-Depth Proteomic Analysis of the Hippocampus in a Rat Model after Cerebral Ischaemic Injury and Repair by Danhong Injection (DHI)

PubMed Central

Cui, Yiran; Liu, Xin; Li, Xianyu; Yang, Hongjun

2017-01-01

Stroke is the second most common cause of death worldwide. A systematic description and characterization of the strokes and the effects induced in the hippocampus have not been performed so far. Here, we analysed the protein expression in the hippocampus 24 h after cerebral ischaemic injury and repair. Drug intervention using Danhong injection (DHI), which has been reported to have good therapeutic effects in a clinical setting, was selected for our study of cerebral ischaemia repair in rat models. A larger proteome dataset and total 4091 unique proteins were confidently identified in three biological replicates by combining tissue extraction for rat hippocampus and LC-MS/MS analysis. A label-free approach was then used to quantify the differences among the four experimental groups (Naive, Sham, middle cerebral artery occlusion (MCAO) and MCAO + DHI groups) and showed that about 2500 proteins on average were quantified in each of the experiment group. Bioinformatics analysis revealed that in total 280 unique proteins identified above were differentially expressed (P < 0.05). By combining the subcellular localization, hierarchical clustering and pathway information with the results from injury and repair phase, 12 significant expressed proteins were chosen and verified with respect to their potential as candidates for cerebral ischaemic injury by Western blot. The primary three signalling pathways of the candidates related may be involved in molecular mechanisms related to cerebral ischaemic injury. In addition, a glycogen synthase kinase-3β (Gsk-3β) inhibitor of the candidates with the best corresponding expression trends between western blotting (WB) and label-free quantitative results were chosen for further validation. The results of Western blot analysis of protein expression and 2,3,5- chloride three phenyl tetrazole (TTC) staining of rat brains showed that DHI treatment and Gsk-3β inhibitor are both able to confer protection against ischaemic injury in rat

The effects of therapeutic taping on gross motor function in children with cerebral palsy.

PubMed

Footer, Cheryl Burditt

2006-01-01

Therapeutic taping to address dysfunctional sitting control in children with cerebral palsy (CP) was investigated in this study. Eighteen children with quadriplegic CP, Gross Motor Function Classification System for Cerebral Palsy levels IV (n = 9) and V (n = 9) participated in the 12-week program. Subjects were assigned randomly to one of two groups: therapeutic taping + physical therapy or physical therapy only. Therapeutic taping was applied for periods of up to 72 hours over the paraspinal region. The effects were assessed with the Gross Motor Function Measure (GMFM-88) at baseline, six weeks, and 12 weeks. A factorial analysis of variance was used to examine group differences over time. No significant differences were found for the GMFM-88 scores between groups over time. Therapeutic taping does not evoke a positive functional change in the seated postural control of children with quadriplegic cerebral palsy. Subjective observation, however, suggested that one child with athetosis benefited from therapeutic taping over the paraspinal region.

Cerebral arterial bolus arrival time is prolonged in multiple sclerosis and associated with disability

PubMed Central

Paling, David; Thade Petersen, Esben; Tozer, Daniel J; Altmann, Daniel R; Wheeler-Kingshott, Claudia AM; Kapoor, Raju; Miller, David H; Golay, Xavier

2014-01-01

Alterations in the overall cerebral hemodynamics have been reported in multiple sclerosis (MS); however, their cause and significance is unknown. While potential venous causes have been examined, arterial causes have not. In this study, a multiple delay time arterial spin labeling magnetic resonance imaging sequence at 3T was used to quantify the arterial hemodynamic parameter bolus arrival time (BAT) and cerebral blood flow (CBF) in normal-appearing white matter (NAWM) and deep gray matter in 33 controls and 35 patients with relapsing–remitting MS. Bolus arrival time was prolonged in MS in NAWM (1.0±0.2 versus 0.9±0.2 seconds, P=0.031) and deep gray matter (0.90±0.18 versus 0.80±0.14 seconds, P=0.001) and CBF was increased in NAWM (14±4 versus 10±2 mL/100 g/min, P=0.001). Prolonged BAT in NAWM (P=0.042) and deep gray matter (P=0.01) were associated with higher expanded disability status score. This study demonstrates alteration in cerebral arterial hemodynamics in MS. One possible cause may be widespread inflammation. Bolus arrival time was longer in patients with greater disability independent of atrophy and T2 lesion load, suggesting alterations in cerebral arterial hemodynamics may be a marker of clinically relevant pathology. PMID:24045400

Scaling of cerebral blood perfusion in primates and marsupials.

PubMed

Seymour, Roger S; Angove, Sophie E; Snelling, Edward P; Cassey, Phillip

2015-08-01

The evolution of primates involved increasing body size, brain size and presumably cognitive ability. Cognition is related to neural activity, metabolic rate and rate of blood flow to the cerebral cortex. These parameters are difficult to quantify in living animals. This study shows that it is possible to determine the rate of cortical brain perfusion from the size of the internal carotid artery foramina in skulls of certain mammals, including haplorrhine primates and diprotodont marsupials. We quantify combined blood flow rate in both internal carotid arteries as a proxy of brain metabolism in 34 species of haplorrhine primates (0.116-145 kg body mass) and compare it to the same analysis for 19 species of diprotodont marsupials (0.014-46 kg). Brain volume is related to body mass by essentially the same exponent of 0.70 in both groups. Flow rate increases with haplorrhine brain volume to the 0.95 power, which is significantly higher than the exponent (0.75) expected for most organs according to 'Kleiber's Law'. By comparison, the exponent is 0.73 in marsupials. Thus, the brain perfusion rate increases with body size and brain size much faster in primates than in marsupials. The trajectory of cerebral perfusion in primates is set by the phylogenetically older groups (New and Old World monkeys, lesser apes) and the phylogenetically younger groups (great apes, including humans) fall near the line, with the highest perfusion. This may be associated with disproportionate increases in cortical surface area and mental capacity in the highly social, larger primates. © 2015. Published by The Company of Biologists Ltd.

The cerebral neurobiology of anxiety, anxiety displacement, and anxiety denial.

PubMed

Gottschalk, L A; Fronczek, J; Abel, L; Buchsbaum, M S; Fallon, J H

2001-01-01

Previous studies examining the relationship of anxiety scores, derived from the content analysis of speech of normal individuals, have revealed that the anxiety scores occurring in the dreams associated with rapid eye movement (REM) sleep are significantly correlated with localized cerebral glucose metabolic rates assessed by positron emission tomography (PET) scanning. These significant intercorrelations occur in different cerebral areas when the anxiety scores are obtained from mental experiences reported during non-REM sleep or during wakeful silent mentation. The purpose of the present study was to examine the intercorrelations found between anxiety attributed to the self, anxiety-displacement, and anxiety denial measured from computerized content analysis of 5-min verbal reports of subjective thoughts and feelings obtained from wakeful normal subjects and localized cerebral glucose metabolic rates during PET scanning. The subjects were 10 wakeful young males. Their anxiety scores were derived from computerized content analysis of 5-min reports they gave of their subjective thoughts, feelings and fantasies during a 30-min period following an intravenous injection of F D-deoxyglucose (FDG). The subjects were moved 32--45 min after this injection to obtain a PET scan, which records all of the localized cerebral glucose metabolic rates during the 30 min following the FDG injection. Significant intercorrelations of localized cerebral glucose metabolic rates with the scores of self-anxiety, anxiety displacement, and anxiety-denial were found in dissimilar cerebral locations depending on the type of anxiety involved. The significant correlations occurred in brain regions known to be associated with the functions of emotions, cognition, memory, and vision. Specific combinations of cerebral areas, based on glucose metabolic rates, appear to distinguish and be associated with different verbal expressions of anxiety. Replication of this preliminary research will be

Cerebral hemodynamics at altitude: effects of hyperventilation and acclimatization on cerebral blood flow and oxygenation.

PubMed

Sanborn, Matthew R; Edsell, Mark E; Kim, Meeri N; Mesquita, Rickson; Putt, Mary E; Imray, Chris; Yow, Heng; Wilson, Mark H; Yodh, Arjun G; Grocott, Mike; Martin, Daniel S

2015-06-01

Alterations in cerebral blood flow (CBF) and cerebral oxygenation are implicated in altitude-associated diseases. We assessed the dynamic changes in CBF and peripheral and cerebral oxygenation engendered by ascent to altitude with partial acclimatization and hyperventilation using a combination of near-infrared spectroscopy, transcranial Doppler ultrasound, and diffuse correlation spectroscopy. Peripheral (Spo2) and cerebral (Scto2) oxygenation, end-tidal carbon dioxide (ETCO2), and cerebral hemodynamics were studied in 12 subjects using transcranial Doppler and diffuse correlation spectroscopy (DCS) at 75 m and then 2 days and 7 days after ascending to 4559 m above sea level. After obtaining baseline measurements, subjects hyperventilated to reduce baseline ETCO2 by 50%, and a further set of measurements were obtained. Cerebral oxygenation and peripheral oxygenation showed a divergent response, with cerebral oxygenation decreasing at day 2 and decreasing further at day 7 at altitude, whereas peripheral oxygenation decreased on day 2 before partially rebounding on day 7. Cerebral oxygenation decreased after hyperventilation at sea level (Scto2 from 68.8% to 63.5%; P<.001), increased after hyperventilation after 2 days at altitude (Scto2 from 65.6% to 69.9%; P=.001), and did not change after hyperventilation after 7 days at altitude (Scto2 from 62.2% to 63.3%; P=.35). An intensification of the normal cerebral hypocapnic vasoconstrictive response occurred after partial acclimatization in the setting of divergent peripheral and cerebral oxygenation. This may help explain why hyperventilation fails to improve cerebral oxygenation after partial acclimatization as it does after initial ascent. The use of DCS is feasible at altitude and provides a direct measure of CBF indices with high temporal resolution. Copyright © 2015 Wilderness Medical Society. Published by Elsevier Inc. All rights reserved.

Improvement of Cerebral Hypoperfusion with Levothyroxine Therapy in Hashimoto's Encephalopathy Demonstrated by 99mTc-HMPAO-SPECT

PubMed Central

Schnedl, Wolfgang J.; Mirzaei, Siroos; Wallner-Liebmann, Sandra J.; Tafeit, Erwin; Mangge, Harald; Krause, Robert; Lipp, Rainer W.

2013-01-01

Background Hashimoto's encephalopathy (HE) is a rare immune-mediated encephalopathy associated with autoimmune Hashimoto's thyroiditis. Objectives and Methods We report on a patient with HE and significant clinical improvement correlating with an increase in cerebral blood flow demonstrated by hexamethylpropyleneamine oxime (HMPAO) single-photon emission computed tomography (SPECT). HMPAO-SPECT was performed with 740 MBq of technetium-99m-HMPAO. To demonstrate the improvement in regional cerebral blood flow, individual regions of interest were drawn around visually diminished HMPAO uptake, the lesion to reference region ratio was calculated and transverse section images and semi-quantitative measurements were performed. Results We show a 5-year follow-up with significant clinical improvement, a 10-fold reduction in autoantibodies to thyroid peroxidase and an approximately 20% improvement in cerebral blood flow with HMPAO-SPECT. Conclusion Adequate levothyroxine treatment achieving and maintaining euthyroidism should be considered as therapy to lower autoantibodies and improve clinical outcome in patients with Hashimoto's thyroiditis and encephalopathy. PMID:24783049

Role of Hydrogen Sulfide in Early Blood-Brain Barrier Disruption following Transient Focal Cerebral Ischemia

PubMed Central

Jiang, Zheng; Li, Chun; Manuel, Morganne L.; Yuan, Shuai; Kevil, Christopher G.; McCarter, Kimberly D.; Lu, Wei; Sun, Hong

2015-01-01

We determined the role of endogenous hydrogen sulfide (H₂S) in cerebral vasodilation/hyperemia and early BBB disruption following ischemic stroke. A cranial window was prepared over the left frontal, parietal and temporal cortex in mice. Transient focal cerebral Ischemia was induced by directly ligating the middle cerebral artery (MCA) for two hours. Regional vascular response and cerebral blood flow (CBF) during ischemia and reperfusion were measured in real time. Early BBB disruption was assessed by Evans Blue (EB) and sodium fluorescein (Na-F) extravasation at 3 hours of reperfusion. Topical treatment with DL-propargylglycine (PAG, an inhibitor for cystathionine γ-lyase (CSE)) and aspartate (ASP, inhibitor for cysteine aminotransferase/3-mercaptopyruvate sulfurtransferase (CAT/3-MST)), but not O-(Carboxymethyl)hydroxylamine hemihydrochloride (CHH, an inhibitor for cystathionine β-synthase (CBS)), abolished postischemic cerebral vasodilation/hyperemia and prevented EB and Na-F extravasation. CSE knockout (CSE-/-) reduced postischemic cerebral vasodilation/hyperemia but only inhibited Na-F extravasation. An upregulated CBS was found in cerebral cortex of CSE-/- mice. Topical treatment with CHH didn’t further alter postischemic cerebral vasodilation/hyperemia, but prevented EB extravasation in CSE-/- mice. In addition, L-cysteine-induced hydrogen sulfide (H2S) production similarly increased in ischemic side cerebral cortex of control and CSE-/- mice. Our findings suggest that endogenous production of H2S by CSE and CAT/3-MST during reperfusion may be involved in postischemic cerebral vasodilation/hyperemia and play an important role in early BBB disruption following transient focal cerebral ischemia. PMID:25695633

Regional Cerebral Blood Flow during Wakeful Rest in Older Subjects with Mild to Severe Obstructive Sleep Apnea.

PubMed

Baril, Andrée-Ann; Gagnon, Katia; Arbour, Caroline; Soucy, Jean-Paul; Montplaisir, Jacques; Gagnon, Jean-François; Gosselin, Nadia

2015-09-01

To evaluate changes in regional cerebral blood flow (rCBF) during wakeful rest in older subjects with mild to severe obstructive sleep apnea (OSA) and healthy controls, and to identify markers of OSA severity that predict altered rCBF. High-resolution (99m)Tc-HMPAO SPECT imaging during wakeful rest. Research sleep laboratory affiliated with a University hospital. Fifty untreated OSA patients aged between 55 and 85 years, divided into mild, moderate, and severe OSA, and 20 age-matched healthy controls. N/A. Using statistical parametric mapping, rCBF was compared between groups and correlated with clinical, respiratory, and sleep variables. Whereas no rCBF change was observed in mild and moderate groups, participants with severe OSA had reduced rCBF compared to controls in the left parietal lobules, left precentral gyrus, bilateral postcentral gyri, and right precuneus. Reduced rCBF in these regions and in areas of the bilateral frontal and left temporal cortex was associated with more hypopneas, snoring, hypoxemia, and sleepiness. Higher apnea, microarousal, and body mass indexes were correlated to increased rCBF in the basal ganglia, insula, and limbic system. While older individuals with severe obstructive sleep apnea (OSA) had hypoperfusion in the sensorimotor and parietal areas, respiratory variables and subjective sleepiness were correlated with extended regions of hypoperfusion in the lateral cortex. Interestingly, OSA severity, sleep fragmentation, and obesity correlated with increased perfusion in subcortical and medial cortical regions. Anomalies with such a distribution could result in cognitive deficits and reflect impaired vascular regulation, altered neuronal integrity, and/or undergoing neurodegenerative processes. © 2015 Associated Professional Sleep Societies, LLC.

Relationships between Lower Limb Muscle Strength and Locomotor Capacity in Children and Adolescents with Cerebral Palsy Who Walk Independently

ERIC Educational Resources Information Center

Ferland, Chantale; Lepage, Celine; Moffet, Helene; Maltais, Desiree B.

2012-01-01

This study aimed to quantify relationships between lower limb muscle strength and locomotor capacity for children and adolescents with cerebral palsy (CP) to identify key muscle groups for strength training. Fifty 6- to 16-year-olds with CP (Gross Motor Function Classification System level I or II) participated. Isometric muscle strength of hip…

Evaluation of cerebral maturation by visual and quantitative analysis of resting electroencephalography in children with primary nocturnal enuresis.

PubMed

Hallioğlu, O; Ozge, A; Comelekoglu, U; Topaloglu, A K; Kanik, A; Duzovali, O; Yilgor, E

2001-10-01

This study was undertaken to evaluate resting electroencephalographic (EEG) changes and their relations to cerebral maturation in children with primary nocturnal enuresis. Cerebral maturation is known to be important in the pathogenesis of this disorder. Twenty-five right-handed patients with primary nocturnal enuresis, aged 6 to 14 years, and 23 age- and sex-matched healthy children were included in this cross-sectional case-control study. The abnormalities detected using such techniques as hemispheral asymmetry, regional differences, and hyperventilation response in addition to visual and quantitative EEG analysis were examined statistically by multivariate analysis. A decrease in alpha activity in the left (dominant hemisphere) temporal lobe and in the frontal lobes bilaterally and an increase in delta activity in the right temporal region were observed. We concluded that insufficient cerebral maturation is an important factor in the pathogenesis of primary nocturnal enuresis, and EEG, as a noninvasive and inexpensive method, could be used in evaluating cerebral maturation.

Quantifying the energy required for groundwater pumping across a regional aquifer system

NASA Astrophysics Data System (ADS)

Ronayne, M. J.; Shugert, D. T.

2017-12-01

Groundwater pumping can be a substantial source of energy expenditure, particularly in semiarid regions with large depths to water. In this study we assessed the energy required for groundwater pumping in the Denver Basin aquifer system, a group of sedimentary rock aquifers used for municipal water supply in Colorado. In recent decades, declining water levels in the Denver Basin aquifers has resulted in increased pumping lifts and higher energy use rates. We quantified the spatially variable energy intensity for groundwater pumping by analyzing spatial variations in the lift requirement. The median energy intensities for two major aquifers were 1.2 and 1.8 kWh m-3. Considering typical municipal well production rates and household water use in the study area, these results indicate that the energy cost associated with groundwater pumping can be a significant fraction (>20%) of the total electricity consumption for all household end uses. Pumping at this scale (hundreds of municipal wells producing from deep aquifers) also generates substantial greenhouse gas emissions. Analytical wellfield modeling conducted as part of this study clearly demonstrates how multiple components of the lift impact the energy requirement. Results provide guidance for water management strategies that reduce energy expenditure.

Cerebral Microbleeds: Burden Assessment by Using Quantitative Susceptibility Mapping

PubMed Central

Liu, Tian; Surapaneni, Krishna; Lou, Min; Cheng, Liuquan; Spincemaille, Pascal

2012-01-01

Purpose: To assess quantitative susceptibility mapping (QSM) for reducing the inconsistency of standard magnetic resonance (MR) imaging sequences in measurements of cerebral microbleed burden. Materials and Methods: This retrospective study was HIPAA compliant and institutional review board approved. Ten patients (5.6%) were selected from among 178 consecutive patients suspected of having experienced a stroke who were imaged with a multiecho gradient-echo sequence at 3.0 T and who had cerebral microbleeds on T2*-weighted images. QSM was performed for various ranges of echo time by using both the magnitude and phase components in the morphology-enabled dipole inversion method. Cerebral microbleed size was measured by two neuroradiologists on QSM images, T2*-weighted images, susceptibility-weighted (SW) images, and R2* maps calculated by using different echo times. The sum of susceptibility over a region containing a cerebral microbleed was also estimated on QSM images as its total susceptibility. Measurement differences were assessed by using the Student t test and the F test; P < .05 was considered to indicate a statistically significant difference. Results: When echo time was increased from approximately 20 to 40 msec, the measured cerebral microbleed volume increased by mean factors of 1.49 ± 0.86 (standard deviation), 1.64 ± 0.84, 2.30 ± 1.20, and 2.30 ± 1.19 for QSM, R2*, T2*-weighted, and SW images, respectively (P < .01). However, the measured total susceptibility with QSM did not show significant change over echo time (P = .31), and the variation was significantly smaller than any of the volume increases (P < .01 for each). Conclusion: The total susceptibility of a cerebral microbleed measured by using QSM is a physical property that is independent of echo time. © RSNA, 2011 PMID:22056688

Cerebral monitoring during cardiopulmonary bypass in children.

PubMed

Kern, F H; Schell, R M; Greeley, W J

1993-07-01

Although cerebral monitoring during CPB remains primarily investigational, recent data support its clinical utility. In particular, it is cerebral metabolic monitoring that provides meaningful information in terms of preparing the brain for dhCPB and dhCA. Cerebral blood flow or cerebral blood flow velocity monitoring is less beneficial due to the presence of luxuriant cerebral blood flow at deep hypothermic temperatures. Conventional temperature monitoring can be improved upon by adding jugular venous oxygen saturation monitoring to satisfy the primary goal of cerebral protection--uniform cerebral cooling and metabolic suppression. Although online measures of cerebral cellular metabolism are not widely available, early experience with near infrared technology suggests that it is a feasible and reliable monitor of cerebral metabolic activity and is likely to represent an important noninvasive continuous monitor in the near future. CMRO2 recovery data have suggested that cerebral metabolic suppression is more severe the longer the period of dhCA. Cerebral protection strategies, such as intermittent cerebral perfusion have demonstrated less metabolic suppression of dhCA in animal models and are currently undergoing clinical evaluation in our institution. Finally, the postoperative period remains a high-risk period for neurologic injury because temperatures are normothermic, cardiac output is reduced, cerebral autoregulation is impaired, and management strategies, such as hyperventilation, are commonly used to increase pulmonary blood flow with little knowledge on its effects on cerebral perfusion.

Functional and anatomical evidence of cerebral tissue hypoxia in young sickle cell anemia mice.

PubMed

Cahill, Lindsay S; Gazdzinski, Lisa M; Tsui, Albert Ky; Zhou, Yu-Qing; Portnoy, Sharon; Liu, Elaine; Mazer, C David; Hare, Gregory Mt; Kassner, Andrea; Sled, John G

2017-03-01

Cerebral ischemia is a significant source of morbidity in children with sickle cell anemia; however, the mechanism of injury is poorly understood. Increased cerebral blood flow and low hemoglobin levels in children with sickle cell anemia are associated with increased stroke risk, suggesting that anemia-induced tissue hypoxia may be an important factor contributing to subsequent morbidity. To better understand the pathophysiology of brain injury, brain physiology and morphology were characterized in a transgenic mouse model, the Townes sickle cell model. Relative to age-matched controls, sickle cell anemia mice demonstrated: (1) decreased brain tissue pO 2 and increased expression of hypoxia signaling protein in the perivascular regions of the cerebral cortex; (2) elevated basal cerebral blood flow , consistent with adaptation to anemia-induced tissue hypoxia; (3) significant reduction in cerebrovascular blood flow reactivity to a hypercapnic challenge; (4) increased diameter of the carotid artery; and (5) significant volume changes in white and gray matter regions in the brain, as assessed by ex vivo magnetic resonance imaging. Collectively, these findings support the hypothesis that brain tissue hypoxia contributes to adaptive physiological and anatomic changes in Townes sickle cell mice. These findings may help define the pathophysiology for stroke in children with sickle cell anemia.

Functional and anatomical evidence of cerebral tissue hypoxia in young sickle cell anemia mice

PubMed Central

Gazdzinski, Lisa M; Tsui, Albert KY; Zhou, Yu-Qing; Portnoy, Sharon; Liu, Elaine; Mazer, C David; Hare, Gregory MT; Kassner, Andrea; Sled, John G

2016-01-01

Cerebral ischemia is a significant source of morbidity in children with sickle cell anemia; however, the mechanism of injury is poorly understood. Increased cerebral blood flow and low hemoglobin levels in children with sickle cell anemia are associated with increased stroke risk, suggesting that anemia-induced tissue hypoxia may be an important factor contributing to subsequent morbidity. To better understand the pathophysiology of brain injury, brain physiology and morphology were characterized in a transgenic mouse model, the Townes sickle cell model. Relative to age-matched controls, sickle cell anemia mice demonstrated: (1) decreased brain tissue pO2 and increased expression of hypoxia signaling protein in the perivascular regions of the cerebral cortex; (2) elevated basal cerebral blood flow , consistent with adaptation to anemia-induced tissue hypoxia; (3) significant reduction in cerebrovascular blood flow reactivity to a hypercapnic challenge; (4) increased diameter of the carotid artery; and (5) significant volume changes in white and gray matter regions in the brain, as assessed by ex vivo magnetic resonance imaging. Collectively, these findings support the hypothesis that brain tissue hypoxia contributes to adaptive physiological and anatomic changes in Townes sickle cell mice. These findings may help define the pathophysiology for stroke in children with sickle cell anemia. PMID:27165012

Chronic cocaine disrupts neurovascular networks and cerebral function: optical imaging studies in rodents

NASA Astrophysics Data System (ADS)

Zhang, Qiujia; You, Jiang; Volkow, Nora D.; Choi, Jeonghun; Yin, Wei; Wang, Wei; Pan, Yingtian; Du, Congwu

2016-02-01

Cocaine abuse can lead to cerebral strokes and hemorrhages secondary to cocaine's cerebrovascular effects, which are poorly understood. We assessed cocaine's effects on cerebrovascular anatomy and function in the somatosensory cortex of the rat's brain. Optical coherence tomography was used for in vivo imaging of three-dimensional cerebral blood flow (CBF) networks and to quantify CBF velocities (CBFv), and multiwavelength laser-speckle-imaging was used to simultaneously measure changes in CBFv, oxygenated (Δ[HbO2]) and deoxygenated hemoglobin (Δ[HbR]) concentrations prior to and after an acute cocaine challenge in chronically cocaine exposed rats. Immunofluorescence techniques on brain slices were used to quantify microvasculature density and levels of vascular endothelial growth factor (VEGF). After chronic cocaine (2 and 4 weeks), CBFv in small vessels decreased, whereas vasculature density and VEGF levels increased. Acute cocaine further reduced CBFv and decreased Δ[HbO2] and this decline was larger and longer lasting in 4 weeks than 2 weeks cocaine-exposed rats, which indicates that risk for ischemia is heightened during intoxication and that it increases with chronic exposures. These results provide evidence of cocaine-induced angiogenesis in cortex. The CBF reduction after chronic cocaine exposure, despite the increases in vessel density, indicate that angiogenesis was insufficient to compensate for cocaine-induced disruption of cerebrovascular function.

Can an anti-gravity treadmill improve stability of children with cerebral palsy?

PubMed

Birgani, P M; Ashtiyani, M; Rasooli, A; Shahrokhnia, M; Shahrokhi, A; Mirbagheri, M M

2016-08-01

We aimed to study the effects of an anti-gravity treadmill (AlterG) training on balance and postural stability in children with cerebral palsy (CP). AlterG training was performed 3 days/week for 8 weeks, with up to 45 minutes of training per session. The subject was evaluated before and after the 8-week training. The effects of training on the balance and postural stability was evaluated based on the Romberg test that was performed by using a posturography device. The parameters quantifying Center-of-Pressure (CoP) were calculated using different analytical approaches including power spectral density and principal components analyses. All of the key parameters including the Stabilogram, the Fast Fourier Transform (FFT) Energy, the Eigenvectors, and the Eigenvalues of CoP were modified between 14%-84%. The results indicated that the balance features were improved substantially after training. The clinical implication is that the AlterG has the potential to effectively improve postural stability in children with cerebral palsy.

FDG-PET study of the bilateral subthalamic nucleus stimulation effects on the regional cerebral metabolism in advanced Parkinson disease.

PubMed

Li, D; Zuo, C; Guan, Y; Zhao, Y; Shen, J; Zan, S; Sun, B

2006-01-01

The aim of the study was to evaluate the changes in regional cerebral metabolic rate of glucose (rCMRGlu) induced by bilateral subthalamic nucleurs (STN) stimulation in advanced Parkinson's disease (PD). 18F-Fluorodeoxyglucose (FDG) PET data obtained before and one month after stimulation were analyzed with statistical parametric mapping (SPM). As a result of clinically effective bilateral STN stimulation, rCMRGlu increased in lateral globus pallidus (GP), upper brain stem, dorsolateral prefrontal cortex (DLPFC) and posterior parietal-occipital cortex, and decreased in the orbital frontal cortex and parahippocampus gyrus (p < 0.001). We conclude that the alleviation of clinical symptoms in advanced PD by bilateral STN stimulation may be the result of activation of both ascending and descending pathways from STN and of restoration of the impaired higher-order cortex functions.

Quantifying the Impact of Tropospheric Ozone on Crops Productivity at regional scale using JULES-crop

NASA Astrophysics Data System (ADS)

Leung, F.

2016-12-01

Tropospheric ozone (O3) is the third most important anthropogenic greenhouse gas. It is causing significant crop production losses. Currently, O3 concentrations are projected to increase globally, which could have a significant impact on food security. The Joint UK Land Environment Simulator modified to include crops (JULES-crop) is used here to quantify the impacts of tropospheric O3 on crop production at the regional scale until 2100. We evaluate JULES-crop against the Soybean Free-Air-Concentration-Enrichment (SoyFACE) experiment in Illinois, USA. Experimental data from SoyFACE and various literature sources is used to calibrate the parameters for soybean and ozone damage parameters in soybean in JULES-crop. The calibrated model is then applied for a transient factorial set of JULES-crop simulations over 1960-2005. Simulated yield changes are attributed to individual environmental drivers, CO2, O3 and climate change, across regions and for different crops. A mixed scenario of RCP 2.6 and RCP 8.5 climatology and ozone are simulated to explore the implication of policy. The overall findings are that regions with high ozone concentration such as China and India suffer the most from ozone damage, soybean is more sensitive to O3 than other crops. JULES-crop predicts CO2 fertilisation would increase the productivity of vegetation. This effect, however, is masked by the negative impacts of tropospheric O3. Using data from FAO and JULES-crop estimated that ozone damage cost around 55.4 Billion USD per year on soybean. Irrigation improves the simulation of rice only, and it increases the relative ozone damage because drought can reduce the ozone from entering the plant stomata. RCP 8.5 scenario results in a high yield for all crops mainly due to the CO2 fertilisation effect. Mixed climate scenarios simulations suggest that RCP 8.5 CO2 concentration and RCP 2.6 O3 concentration result in the highest yield. Further works such as more crop FACE-O3 experiments and more Crop

The role of the endoplasmic reticulum stress response following cerebral ischemia.

PubMed

Hadley, Gina; Neuhaus, Ain A; Couch, Yvonne; Beard, Daniel J; Adriaanse, Bryan A; Vekrellis, Kostas; DeLuca, Gabriele C; Papadakis, Michalis; Sutherland, Brad A; Buchan, Alastair M

2018-06-01

Background Cornu ammonis 3 (CA3) hippocampal neurons are resistant to global ischemia, whereas cornu ammonis (CA1) 1 neurons are vulnerable. Hamartin expression in CA3 neurons mediates this endogenous resistance via productive autophagy. Neurons lacking hamartin demonstrate exacerbated endoplasmic reticulum stress and increased cell death. We investigated endoplasmic reticulum stress responses in CA1 and CA3 regions following global cerebral ischemia, and whether pharmacological modulation of endoplasmic reticulum stress or autophagy altered neuronal viability . Methods In vivo: male Wistar rats underwent sham or 10 min of transient global cerebral ischemia. CA1 and CA3 areas were microdissected and endoplasmic reticulum stress protein expression quantified at 3 h and 12 h of reperfusion. In vitro: primary neuronal cultures (E18 Wistar rat embryos) were exposed to 2 h of oxygen and glucose deprivation or normoxia in the presence of an endoplasmic reticulum stress inducer (thapsigargin or tunicamycin), an endoplasmic reticulum stress inhibitor (salubrinal or 4-phenylbutyric acid), an autophagy inducer ([4'-(N-diethylamino) butyl]-2-chlorophenoxazine (10-NCP)) or autophagy inhibitor (3-methyladenine). Results In vivo, decreased endoplasmic reticulum stress protein expression (phospho-eIF2α and ATF4) was observed at 3 h of reperfusion in CA3 neurons following ischemia, and increased in CA1 neurons at 12 h of reperfusion. In vitro, endoplasmic reticulum stress inducers and high doses of the endoplasmic reticulum stress inhibitors also increased cell death. Both induction and inhibition of autophagy also increased cell death. Conclusion Endoplasmic reticulum stress is associated with neuronal cell death following ischemia. Neither reduction of endoplasmic reticulum stress nor induction of autophagy demonstrated neuroprotection in vitro, highlighting their complex role in neuronal biology following ischemia.

Quantifying Impacts of Land-use and Land Cover Change in a Changing Climate at the Regional Scale using an Integrated Earth System Modeling Approach

NASA Astrophysics Data System (ADS)

Huang, M.

2016-12-01

Earth System models (ESMs) are effective tools for investigating the water-energy-food system interactions under climate change. In this presentation, I will introduce research efforts at the Pacific Northwest National Laboratory towards quantifying impacts of LULCC on the water-energy-food nexus in a changing climate using an integrated regional Earth system modeling framework: the Platform for Regional Integrated Modeling and Analysis (PRIMA). Two studies will be discussed to showcase the capability of PRIMA: (1) quantifying changes in terrestrial hydrology over the Conterminous US (CONUS) from 2005 to 2095 using the Community Land Model (CLM) driven by high-resolution downscaled climate and land cover products from PRIMA, which was designed for assessing the impacts of and potential responses to climate and anthropogenic changes at regional scales; (2) applying CLM over the CONUS to provide the first county-scale model validation in simulating crop yields and assessing associated impacts on the water and energy budgets using CLM. The studies demonstrate the benefits of incorporating and coupling human activities into complex ESMs, and critical needs to account for the biogeophysical and biogeochemical effects of LULCC in climate impacts studies, and in designing mitigation and adaptation strategies at a scale meaningful for decision-making. Future directions in quantifying LULCC impacts on the water-energy-food nexus under a changing climate, as well as feedbacks among climate, energy production and consumption, and natural/managed ecosystems using an Integrated Multi-scale, Multi-sector Modeling framework will also be discussed.

Cerebral Blood Flow and Cerebral Edema in Rats With Diabetic Ketoacidosis

PubMed Central

Yuen, Natalie; Anderson, Steven E.; Glaser, Nicole; Tancredi, Daniel J.; O'Donnell, Martha E.

2008-01-01

OBJECTIVE— Cerebral edema (CE) is a potentially life-threatening complication of diabetic ketoacidosis (DKA) in children. Osmotic fluctuations during DKA treatment have been considered responsible, but recent data instead suggest that cerebral hypoperfusion may be involved and that activation of cerebral ion transporters may occur. Diminished cerebral blood flow (CBF) during DKA, however, has not been previously demonstrated. We investigated CBF and edema formation in a rat model of DKA and determined the effects of bumetanide, an inhibitor of Na-K-Cl cotransport. RESEARCH DESIGN AND METHODS— Juvenile rats with streptozotocin-induced DKA were treated with intravenous saline and insulin, similar to human treatment protocols. CBF was determined by magnetic resonance (MR) perfusion–weighted imaging before and during treatment, and CE was assessed by determining apparent diffusion coefficients (ADCs) using MR diffusion–weighted imaging. RESULTS— CBF was significantly reduced in DKA and was responsive to alterations in pCO2. ADC values were reduced, consistent with cell swelling. The reduction in ADCs correlated with dehydration, as reflected in blood urea nitrogen concentrations. Bumetanide caused a rapid rise in ADCs of DKA rats without significantly changing CBF, while saline/insulin caused a rapid rise in CBF and a gradual rise in ADCs. DKA rats treated with bumetanide plus saline/insulin showed a trend toward more rapid rise in cortical ADCs and a larger rise in striatal CBF than those observed with saline/insulin alone. CONCLUSIONS— These data demonstrate that CE in DKA is accompanied by cerebral hypoperfusion before treatment and suggest that blocking Na-K-Cl cotransport may reduce cerebral cell swelling. PMID:18633109

Revisiting cerebral thromboangiitis obliterans.

PubMed

Hurelbrink, Carrie B; Barnett, Yael; Buckland, Michael E; Wilkinson, Mark; Leicester, Jon; Anderson, Craig; Brennan, Jeffrey; Barnett, Michael

2012-06-15

We describe a 56-year-old patient with progressive cognitive decline in the context of heavy tobacco use and migraine, and imaging evidence of an occlusive terminal cerebral vasculopathy. The results of brain biopsy recapitulated the pathological features described by Lindenberg and Spatz in their classic 1939 treatise on cerebral thromboangiitis obliterans, or cerebral Buerger's disease. Although the condition is associated with heavy smoking, the identification of a hypercoagulable state in our patient suggests a multifactorial pathogenesis. The diagnosis of cerebral thromboangiitis obliterans in life is facilitated by modern neuroimaging and should prompt immediate cessation of smoking and a search for an underlying prothrombotic tendency. Copyright © 2012 Elsevier B.V. All rights reserved.

A new conceptual model for quantifying transboundary contribution of atmospheric pollutants in the East Asian Pacific rim region.

PubMed

Lai, I-Chien; Lee, Chon-Lin; Huang, Hu-Ching

2016-03-01

Transboundary transport of air pollution is a serious environmental concern as pollutant affects both human health and the environment. Many numerical approaches have been utilized to quantify the amounts of pollutants transported to receptor regions, based on emission inventories from possible source regions. However, sparse temporal-spatial observational data and uncertainty in emission inventories might make the transboundary transport contribution difficult to estimate. This study presents a conceptual quantitative approach that uses transport pathway classification in combination with curve fitting models to simulate an air pollutant concentration baseline for pollution background concentrations. This approach is used to investigate the transboundary transport contribution of atmospheric pollutants to a metropolitan area in the East Asian Pacific rim region. Trajectory analysis categorized pollution sources for the study area into three regions: East Asia, Southeast Asia, and Taiwan cities. The occurrence frequency and transboundary contribution results suggest the predominant source region is the East Asian continent. This study also presents an application to evaluate heavy pollution cases for health concerns. This new baseline construction model provides a useful tool for the study of the contribution of transboundary pollution delivered to receptors, especially for areas deficient in emission inventories and regulatory monitoring data for harmful air pollutants. Copyright © 2015 Elsevier Ltd. All rights reserved.

Interleukin-6 mediates enhanced thrombus development in cerebral arterioles following a brief period of focal brain ischemia

PubMed Central

Tang, Ya Hui; Vital, Shantel; Russell, Janice; Seifert, Hilary; Granger, D. Neil

2015-01-01

Objective The cerebral microvasculature is rendered more vulnerable to thrombus formation following a brief (5.0 min) period of focal ischemia. This study examined the contribution of interleukin-6 (IL-6), a neuroprotective and prothrombotic cytokine produced by the brain, to transient ischemia-induced thrombosis in cerebral arterioles. Approach & results The middle cerebral artery of C57BL/6J mice was occluded for 5 minutes, followed by 24 hrs of reperfusion (MCAo/R). Intravital fluorescence microscopy was used to monitor thrombus development in cerebral arterioles induced by light/dye photoactivation. Thrombosis was quantified as the time of onset of platelet aggregation on the vessel wall and the time for complete blood flow cessation. MCAo/R in wild type (WT) mice yielded an acceleration of thrombus formation that was accompanied by increased IL-6 levels in plasma and in post-ischemic brain tissue. The exaggerated thrombosis response to MCAo/R was blunted in WT mice receiving an IL-6 receptor-blocking antibody and in IL-6 deficient (IL-6−/−) mice. Bone marrow chimeras, produced by transplanting IL-6−/− marrow into WT recipients, did not exhibit protection against MCAo/R-induced thrombosis. Conclusions The increased vulnerability of the cerebral vasculature to thrombus development after MCAo/R is mediated by IL-6, which is likely derived from brain cells rather than circulating blood cells. These findings suggest that anti-IL-6 therapy may reduce the likelihood of cerebral thrombus development after a transient ischemic attack. PMID:26054883

Investigating Flow-Structure Interactions in Cerebral Aneurysms

ScienceCinema

None

2018-06-05

Visualization of blood flow in a cerebral aneurysm. Streamlines (colored by fluid velocity magnitude) reveal the complexity of the flow, isocontours of vorticity show blood vortex structures (colored by pressure), and the flexible arterial wall is colored by the stress magnitude, where regions in red indicate areas of high stress. Credits: Science: Paris Perdikaris, Yue Yu, George Em. Karniadakis and Leopold Grinberg Visualization: Joseph A. Insley and Michael E. Papka

Quantitative Changes in Cerebral Perfusion during Urinary Urgency in Women with Overactive Bladder

PubMed Central

Weissbart, Steven J.; Xu, Sihua; Bhavsar, Rupal; Rao, Hengyi

2017-01-01

Purpose To quantitatively measure changes in cerebral perfusion in select regions of interest in the brain during urinary urgency in women with overactive bladder (OAB) using arterial spin labeling (ASL). Methods Twelve women with OAB and 10 controls underwent bladder filling and rated urinary urgency (scale 0–10). ASL fMRI scans were performed (1) in the low urgency state after voiding and (2) high urgency state after drinking oral fluids. Absolute regional cerebral blood flow (rCBF) in select regions of interest was compared between the low and high urgency states. Results There were no significant differences in rCBF between the low and high urgency states in the control group. In the OAB group, rCBF (mean ± SE, ml/100 g/min) increased by 10–14% from the low to the high urgency state in the right anterior cingulate cortex (ACC) (44.56 ± 0.59 versus 49.52 ± 1.49, p < 0.05), left ACC (49.29 ± 0.85 versus 54.02 ± 1.46, p < 0.05), and left insula (50.46 ± 1.72 versus 54.99 ± 1.09, p < 0.05). Whole-brain analysis identified additional areas of activation in the right insula, right dorsolateral prefrontal cortex, and pons/midbrain area. Conclusions Urinary urgency is associated with quantitative increase in cerebral perfusion in regions of the brain associated with processing emotional response to discomfort. PMID:28904950

Effects of Omega-3 Fatty Acids on Resting Cerebral Perfusion in Patients with Mild Cognitive Impairment: A Randomized Controlled Trial.

PubMed

Schwarz, C; Wirth, M; Gerischer, L; Grittner, U; Witte, A V; Köbe, T; Flöel, A

2018-01-01

Alteration of cerebral perfusion can be considered as a possible therapeutic target in mild cognitive impairment. This randomized, placebo-controlled, double-blind proof-of-concept study assessed effects of omega-3 fatty acids on cerebral perfusion in patients with mild cognitive impairment. In thirteen patients (omega:n=5; placebo:n=8) cerebral perfusion was measured before and after 26-weeks intervention within posterior cortical regions using magnetic resonance imaging. There was a medium effect of intervention on cerebral blood flow (η2=0.122) and blood volume (η2=0.098). The omega group showed an increase in blood flow (mean difference: 0.02 [corresponds to 26.1%], 95% confidence interval:0.00-0.05) and blood volume (mean difference: 0.08 [corresponds to 18.5%], 95% confidence interval:0.01-0.15), which was not observed in the placebo group. These preliminary findings suggest that omega-3 fatty acids supplementation may improve perfusion in cerebral regions typically affected in mild cognitive impairment.Regulation of perfusion may help to maintain brain structure and function and potentially delay conversion to dementia.

[Keap1-tat peptide attenuates oxidative stress damage in hippocampal CA1 region and learning and memory deficits following global cerebral ischemia].

PubMed

Tu, Jing-yi; Zhu, Ying; Shang, Shu-ling; Zhang, Xi; Tang, Hui; Wang, Rui-min

2016-02-18

To design Keap1-tat peptide and explore its neuroprotective role on hipocampal CA1 neuron, as well as the effect on spacial learning and memory function following global cerebral ischemia. Adult male Sprague Dawley (SD) rats were subjected to global cerebral ischemia (GCI) by four-vessel occlusion for 15 min and randomly divided into five groups: sham, sham+Keap1-tat, ischemia/reperfusion (I/R), Keap1-tat peptide- and vehicle-administrated groups. For Keap1-tat or vehicle groups, the rats were treated with Keap1-tat (30, 50, 100 μg in 5 μL 0.9% saline) or the same volume vehicle by intracerebroventricular injection (icv) 30 min prior to ischemia. Cresyl violet staining was used to observe the surviving neurons and 4-hydroxy-2-noneal (4-HNE) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) immunostaining were used to detect the change of markers response to oxidative stress in hippocampal CA1 region. The spatial learning and memory function of the rats was evaluated using Morris water maze. Compared with sham group, the number of surviving neurons in ischemia-reperfusion and vehicle groups significantly decreased in the hippocampal CA1 region (P<0.05), while administration of Keap1-tat significantly decreased the damage following GCI (P<0.05), and the dose of 50 μg existed the most effective neuroprotective role. Furthermore, immunostaining intensity of 4-HNE and 8-OHdG, markers of oxidative stress damage attenuated by Keap1-tat peptide as compared with vehicle group in CA1 region. Of significant interest, the time of finding underwater platform in Keap1-tat group animals was significantly short, and after removing the platform, the probe time of Keap1-tat group animals in the original quadrant where the platform was significantly increased compared with that of vehicle and I/R group animals (P<0.05). Keap1-tat peptide can effectively attenuate neuronal damage in hippocampal CA1 region and improve learning and memory function, which might bedue to the attenuation of

Glucose administration after traumatic brain injury improves cerebral metabolism and reduces secondary neuronal injury.

PubMed

Moro, Nobuhiro; Ghavim, Sima; Harris, Neil G; Hovda, David A; Sutton, Richard L

2013-10-16

Clinical studies have indicated an association between acute hyperglycemia and poor outcomes in patients with traumatic brain injury (TBI), although optimal blood glucose levels needed to maximize outcomes for these patients' remain under investigation. Previous results from experimental animal models suggest that post-TBI hyperglycemia may be harmful, neutral, or beneficial. The current studies determined the effects of single or multiple episodes of acute hyperglycemia on cerebral glucose metabolism and neuronal injury in a rodent model of unilateral controlled cortical impact (CCI) injury. In Experiment 1, a single episode of hyperglycemia (50% glucose at 2 g/kg, i.p.) initiated immediately after CCI was found to significantly attenuate a TBI-induced depression of glucose metabolism in cerebral cortex (4 of 6 regions) and subcortical regions (2 of 7) as well as to significantly reduce the number of dead/dying neurons in cortex and hippocampus at 24 h post-CCI. Experiment 2 examined effects of more prolonged and intermittent hyperglycemia induced by glucose administrations (2 g/kg, i.p.) at 0, 1, 3 and 6h post-CCI. The latter study also found significantly improved cerebral metabolism (in 3 of 6 cortical and 3 of 7 subcortical regions) and significant neuroprotection in cortex and hippocampus 1 day after CCI and glucose administration. These results indicate that acute episodes of post-TBI hyperglycemia can be beneficial and are consistent with other recent studies showing benefits of providing exogenous energy substrates during periods of increased cerebral metabolic demand. © 2013 Elsevier B.V. All rights reserved.

Transcranial diffuse optical monitoring of microvascular cerebral hemodynamics after thrombolysis in ischemic stroke

NASA Astrophysics Data System (ADS)

Zirak, Peyman; Delgado-Mederos, Raquel; Dinia, Lavinia; Carrera, David; Martí-Fàbregas, Joan; Durduran, Turgut

2014-01-01

The ultimate goal of therapeutic strategies for ischemic stroke is to reestablish the blood flow to the ischemic region of the brain. However, currently, the local cerebral hemodynamics (microvascular) is almost entirely inaccessible for stroke clinicians at the patient bed-side, and the recanalization of the major cerebral arteries (macrovascular) is the only available measure to evaluate the therapy, which does not always reflect the local conditions. Here we report the case of an ischemic stroke patient whose microvascular cerebral blood flow and oxygenation were monitored by a compact hybrid diffuse optical monitor during thrombolytic therapy. This monitor combined diffuse correlation spectroscopy and near-infrared spectroscopy. The reperfusion assessed by hybrid diffuse optics temporally correlated with the recanalization of the middle cerebral artery (assessed by transcranial-Doppler) and was in agreement with the patient outcome. This study suggests that upon further investigation, diffuse optics might have a potential for bed-side acute stroke monitoring and therapy guidance by providing hemodynamics information at the microvascular level.

Transcranial diffuse optical monitoring of microvascular cerebral hemodynamics after thrombolysis in ischemic stroke.

PubMed

Zirak, Peyman; Delgado-Mederos, Raquel; Dinia, Lavinia; Carrera, David; Martí-Fàbregas, Joan; Durduran, Turgut

2014-01-01

The ultimate goal of therapeutic strategies for ischemic stroke is to reestablish the blood flow to the ischemic region of the brain. However, currently, the local cerebral hemodynamics (microvascular) is almost entirely inaccessible for stroke clinicians at the patient bed-side, and the recanalization of the major cerebral arteries (macrovascular) is the only available measure to evaluate the therapy, which does not always reflect the local conditions. Here we report the case of an ischemic stroke patient whose microvascular cerebral blood flow and oxygenation were monitored by a compact hybrid diffuse optical monitor during thrombolytic therapy. This monitor combined diffuse correlation spectroscopy and near-infrared spectroscopy. The reperfusion assessed by hybrid diffuse optics temporally correlated with the recanalization of the middle cerebral artery (assessed by transcranial-Doppler) and was in agreement with the patient outcome. This study suggests that upon further investigation, diffuse optics might have a potential for bed-side acute stroke monitoring and therapy guidance by providing hemodynamics information at the microvascular level.

Effects of intermittent theta burst stimulation on cerebral blood flow and cerebral vasomotor reactivity.

PubMed

Pichiorri, Floriana; Vicenzini, Edoardo; Gilio, Francesca; Giacomelli, Elena; Frasca, Vittorio; Cambieri, Chiara; Ceccanti, Marco; Di Piero, Vittorio; Inghilleri, Maurizio

2012-08-01

To determine whether intermittent theta burst stimulation influences cerebral hemodynamics, we investigated changes induced by intermittent theta burst stimulation on the middle cerebral artery cerebral blood flow velocity and vasomotor reactivity to carbon dioxide (CO(2)) in healthy participants. The middle cerebral artery flow velocity and vasomotor reactivity were monitored by continuous transcranial Doppler sonography. Changes in cortical excitability were tested by transcranial magnetic stimulation. In 11 healthy participants, before and immediately after delivering intermittent theta burst stimulation, we tested cortical excitability measured by the resting motor threshold and motor evoked potential amplitude over the stimulated hemisphere and vasomotor reactivity to CO(2) bilaterally. The blood flow velocity was monitored in both middle cerebral arteries throughout the experimental session. In a separate session, we tested the effects of sham stimulation under the same experimental conditions. Whereas the resting motor threshold remained unchanged before and after stimulation, motor evoked potential amplitudes increased significantly (P = .04). During and after stimulation, middle cerebral artery blood flow velocities also remained bilaterally unchanged, whereas vasomotor reactivity to CO(2) increased bilaterally (P = .04). The sham stimulation left all variables unchanged. The expected intermittent theta burst stimulation-induced changes in cortical excitability were not accompanied by changes in cerebral blood flow velocities; however, the bilateral increased vasomotor reactivity suggests that intermittent theta burst stimulation influences the cerebral microcirculation, possibly involving subcortical structures. These findings provide useful information on hemodynamic phenomena accompanying intermittent theta burst stimulation, which should be considered in research aimed at developing this noninvasive, low-intensity stimulation technique for safe

Comparison of clipping and coiling in elderly patients with unruptured cerebral aneurysms

PubMed Central

Bekelis, Kimon; Gottlieb, Daniel J.; Su, Yin; O’Malley, A. James; Labropoulos, Nicos; Goodney, Philip; Lawton, Michael T.; MacKenzie, Todd A.

2016-01-01

OBJECTIVE The comparative effectiveness of the 2 treatment options—surgical clipping and endovascular coiling—for unruptured cerebral aneurysms remains an issue of debate and has not been studied in clinical trials. The authors investigated the association between treatment method for unruptured cerebral aneurysms and outcomes in elderly patients. METHODS The authors performed a cohort study of 100% of Medicare fee-for-service claims data for elderly patients who had treatment for unruptured cerebral aneurysms between 2007 and 2012. To control for measured confounding, the authors used propensity score conditioning and inverse probability weighting with mixed effects to account for clustering at the level of the hospital referral region (HRR). An instrumental variable (regional rates of coiling) analysis was used to control for unmeasured confounding and to create pseudo-randomization on the treatment method. RESULTS During the study period, 8705 patients underwent treatment for unruptured cerebral aneurysms and met the study inclusion criteria. Of these patients, 2585 (29.7%) had surgical clipping and 6120 (70.3%) had endovascular coiling. Instrumental variable analysis demonstrated no difference between coiling and clipping in 1-year postoperative mortality (OR 1.25, 95% CI 0.68–2.31) or 90-day readmission rate (OR 1.04, 95% CI 0.66–1.62). However, clipping was associated with a greater likelihood of discharge to rehabilitation (OR 6.39, 95% CI 3.85–10.59) and 3.6 days longer length of stay (LOS; 95% CI 2.90–4.71). The same associations were present in propensity score–adjusted and inverse probability– weighted models. CONCLUSIONS In a cohort of Medicare patients, there was no difference in mortality and the readmission rate between clipping and coiling of unruptured cerebral aneurysms. Clipping was associated with a higher rate of discharge to a rehabilitation facility and a longer LOS. PMID:27203150

Diffusion tensor imaging of the human cerebellar pathways and their interplay with cerebral macrostructure

PubMed Central

Keser, Zafer; Hasan, Khader M.; Mwangi, Benson I.; Kamali, Arash; Ucisik-Keser, Fehime Eymen; Riascos, Roy F.; Yozbatiran, Nuray; Francisco, Gerard E.; Narayana, Ponnada A.

2015-01-01

Cerebellar white matter (WM) connections to the central nervous system are classified functionally into the Spinocerebellar (SC), vestibulocerebellar (VC), and cerebrocerebellar subdivisions. The SC pathways project from spinal cord to cerebellum, whereas the VC pathways project from vestibular organs of the inner ear. Cerebrocerebellar connections are composed of feed forward and feedback connections between cerebrum and cerebellum including the cortico-ponto-cerebellar (CPC) pathways being of cortical origin and the dentate-rubro-thalamo-cortical (DRTC) pathway being of cerebellar origin. In this study we systematically quantified the whole cerebellar system connections using diffusion tensor magnetic resonance imaging (DT-MRI). Ten right-handed healthy subjects (7 males and 3 females, age range 20–51 years) were studied. DT-MRI data were acquired with a voxel size = 2 mm × 2 mm × 2 mm at a 3.0 Tesla clinical MRI scanner. The DT-MRI data were prepared and analyzed using anatomically-guided deterministic tractography methods to reconstruct the SC, DRTC, fronto-ponto-cerebellar (FPC), parieto-ponto-cerebellar (PPC), temporo-ponto-cerebellar (TPC) and occipito-ponto-cerebellar (OPC). The DTI-attributes or the cerebellar tracts along with their cortical representation (Brodmann areas) were presented in standard Montréal Neurological Institute space. All cerebellar tract volumes were quantified and correlated with volumes of cerebral cortical, subcortical gray matter (GM), cerebral WM and cerebellar GM, and cerebellar WM. On our healthy cohort, the ratio of total cerebellar GM-to-WM was ~3.29 ± 0.24, whereas the ratio of cerebral GM-to-WM was approximately 1.10 ± 0.11. The sum of all cerebellar tract volumes is ~25.8 ± 7.3 mL, or a percentage of 1.6 ± 0.45 of the total intracranial volume (ICV). PMID:25904851

Improving 1H MRSI measurement of cerebral lactate for clinical applications.

PubMed

Corrigan, Neva M; Richards, Todd L; Friedman, Seth D; Petropoulos, Helen; Dager, Stephen R

2010-04-30

Accurate measurement of cerebral lactate is critical to the understanding of brain function for psychiatric disorders such as panic disorder and bipolar disorder as well as mitochondrial dysfunction. Proton magnetic spectroscopic imaging (MRSI) techniques can be used to study lactate in vivo; however, accurate measurement of cerebral lactate, which is normally at low basal abundance, can be challenging. In this study, regional lactate measurements obtained with two different MRSI analytic approaches were evaluated using proton echo-planar spectroscopic imaging (PEPSI) data from 18 healthy adults participating in an in vivo sodium lactate infusion study. The results demonstrate that averaging data within a region of interest (ROI) before spectral fitting with LCModel results in significantly improved lactate measurement as compared to averaging chemical concentrations derived from the fitting of individual voxels in the ROI. Simulation results that confirm this finding are also presented. This study additionally outlines an atlas-based approach for the systematic computation of regional distributions of chemical concentrations in large MRSI data sets. Copyright @ 2009 Elsevier Ireland Ltd. All rights reserved.

The effect of donepezil on increased regional cerebral blood flow in the posterior cingulate cortex of a patient with Parkinson's disease dementia.

PubMed

Imamura, Keiko; Wada-Isoe, Kenji; Kowa, Hisanori; Tanabe, Yoshio; Nakashima, Kenji

2008-01-01

It has been reported that the cholinesterase inhibitor, donepezil, improves cognitive decline in patients with Parkinson's disease dementia (PDD). However, this improvement was dominant for frontal lobe dysfunction, and the increase in the Mini-Mental State Examination (MMSE) score was minimal. We report a PDD patient with a decline of regional cerebral blood flow (rCBF) in the posterior cingulate cortex, precunei, and bilateral parietotemporal association cortex, as determined by single-photon emission computed tomography (SPECT) using the easy Z-scores imaging system (e-ZIS). Upon administration of donepezil, both the rCBF and MMSE score increased. The effectiveness of donepezil may vary based on the rCBF pattern in PDD.

Perforator and secondary branch origin in relation to the neck of saccular, cerebral bifurcation aneurysms.

PubMed

Pritz, Michael B

2014-11-01

Perforator and secondary branch origin in relation to the neck of cerebral, saccular bifurcation aneurysms were analyzed. These two features were considered important for treatment. From a series of microsurgically clipped saccular cerebral aneurysms, 142 bifurcation aneurysms had detailed imaging studies and operative records that could be analyzed. The incidence of perforator origin from the aneurysm neck was as follows: basilar, 1/15 (7%); internal carotid artery bifurcation, 4/23 (17%); main stem of the middle cerebral artery/secondary branch of the middle cerebral artery, 6/52 (12%); anterior communicating artery region, 5/46 (11%); and distal bifurcation vessels, 0/6 (0%). Aneurysms arising from the anterior communicating artery between the anterior cerebral arteries had a high incidence of perforator origin from the aneurysm neck. The location of secondary branch origin from the aneurysm neck varied depending on the aneurysm group. Perforator origin from the aneurysm neck was infrequent. A subgroup of anterior communicating artery region aneurysms had a high incidence of perforator origin from the aneurysm neck. Although protection of these neck perforators will be difficult, their identification may be even more challenging. Secondary branch origin from the aneurysm neck varied depending on the aneurysm group. Advanced endovascular techniques are needed to obliterate aneurysms in which the secondary branch(es) arise from the aneurysm neck. If this is not possible, craniotomy and clip ligation will be required if complete aneurysm obliteration is the goal. Copyright © 2014 Elsevier Inc. All rights reserved.

Adaptive grid generation in a patient-specific cerebral aneurysm

NASA Astrophysics Data System (ADS)

Hodis, Simona; Kallmes, David F.; Dragomir-Daescu, Dan

2013-11-01

Adapting grid density to flow behavior provides the advantage of increasing solution accuracy while decreasing the number of grid elements in the simulation domain, therefore reducing the computational time. One method for grid adaptation requires successive refinement of grid density based on observed solution behavior until the numerical errors between successive grids are negligible. However, such an approach is time consuming and it is often neglected by the researchers. We present a technique to calculate the grid size distribution of an adaptive grid for computational fluid dynamics (CFD) simulations in a complex cerebral aneurysm geometry based on the kinematic curvature and torsion calculated from the velocity field. The relationship between the kinematic characteristics of the flow and the element size of the adaptive grid leads to a mathematical equation to calculate the grid size in different regions of the flow. The adaptive grid density is obtained such that it captures the more complex details of the flow with locally smaller grid size, while less complex flow characteristics are calculated on locally larger grid size. The current study shows that kinematic curvature and torsion calculated from the velocity field in a cerebral aneurysm can be used to find the locations of complex flow where the computational grid needs to be refined in order to obtain an accurate solution. We found that the complexity of the flow can be adequately described by velocity and vorticity and the angle between the two vectors. For example, inside the aneurysm bleb, at the bifurcation, and at the major arterial turns the element size in the lumen needs to be less than 10% of the artery radius, while at the boundary layer, the element size should be smaller than 1% of the artery radius, for accurate results within a 0.5% relative approximation error. This technique of quantifying flow complexity and adaptive remeshing has the potential to improve results accuracy and reduce

Longitudinal thalamic diffusion changes after middle cerebral artery infarcts

PubMed Central

Herve, D; Molko, N; Pappata, S; Buffon, F; LeBihan, D; Bousser, M; Chabriat, H

2005-01-01

Background: Cerebral infarcts are responsible for functional alterations and microscopic tissue damage at distance from the ischaemic area. Such remote effects have been involved in stroke recovery. Thalamic hypometabolism is related to motor recovery in middle cerebral artery (MCA) infarcts but little is known concerning the tissue changes underlying these metabolic changes. Diffusion tensor imaging (DTI) is highly sensitive to microstructural tissue alterations and can be used to quantify in vivo the longitudinal microscopic tissue changes occurring in the thalamus after MCA infarcts in humans. Methods: Nine patients underwent DTI after an isolated MCA infarct. Mean diffusivity (MD), fractional anisotropy (FA), and thalamic region volume were measured from the first week to the sixth month after stroke onset in these patients and in 10 age matched controls. Results: MD significantly increased in the ipsilateral thalamus between the first and the sixth month (0.766x10–3 mm2/s first month; 0.792x10–3 mm2/s third month; 0.806x10–3 mm2/s sixth month). No significant modification of FA was detected. In six patients, the ipsilateral/contralateral index of MD was higher than the upper limit of the 95% CI calculated in 10 age matched controls. An early decrease of MD preceded the increase of ipsilateral thalamic diffusion in one patient at the first week and in two other patients at the first month. Conclusion: After MCA infarcts, an increase in diffusion is observed with DTI in the ipsilateral thalamus later than 1 month after the stroke onset. This is presumably because of the progressive loss of neurons and/or glial cells. In some patients, this increase is preceded by a transient decrease in diffusion possibly related to an early swelling of these cells or to microglial activation. Further studies in larger series are needed to assess the clinical correlates of these findings. PMID:15654032

Sodium transport through the cerebral sodium-glucose transporter exacerbates neuron damage during cerebral ischaemia.

PubMed

Yamazaki, Yui; Harada, Shinichi; Wada, Tetsuyuki; Yoshida, Shigeru; Tokuyama, Shogo

2016-07-01

We recently demonstrated that the cerebral sodium-glucose transporter (SGLT) is involved in postischaemic hyperglycaemia-induced exacerbation of cerebral ischaemia. However, the associated SGLT-mediated mechanisms remain unclear. Thus, we examined the involvement of cerebral SGLT-induced excessive sodium ion influx in the development of cerebral ischaemic neuronal damage. [Na+]i was estimated according to sodium-binding benzofuran isophthalate fluorescence. In the in vitro study, primary cortical neurons were prepared from fetuses of ddY mice. Primary cortical neurons were cultured for 5 days before each treatment with reagents, and these survival rates were assessed using biochemical assays. In in vivo study, a mouse model of focal ischaemia was generated using middle cerebral artery occlusion (MCAO). In these experiments, treatment with high concentrations of glucose induced increment in [Na+]i, and this phenomenon was suppressed by the SGLT-specific inhibitor phlorizin. SGLT-specific sodium ion influx was induced using a-methyl-D-glucopyranoside (a-MG) treatments, which led to significant concentration-dependent declines in neuronal survival rates and exacerbated hydrogen peroxide-induced neuronal cell death. Moreover, phlorizin ameliorated these effects. Finally, intracerebroventricular administration of a-MG exacerbated the development of neuronal damage induced by MCAO, and these effects were ameliorated by the administration of phlorizin. Hence, excessive influx of sodium ions into neuronal cells through cerebral SGLT may exacerbate the development of cerebral ischaemic neuronal damage. © 2016 Royal Pharmaceutical Society.

Velocity vector imaging fails to quantify regional myocardial dysfunction in a mouse model of isoprenaline-induced cardiotoxicity.

PubMed

Täng, Margareta Scharin; Redfors, Bjorn; Shao, Yangzhen; Omerovic, Elmir

2012-08-01

Regional myocardial deformation patterns are important in a variety of cardiac diseases, including stress-induced cardiomyopathy. Velocity-vector-based imaging is a speckle-tracking echocardiography (STE)-based algorithm that has been shown to allow in-depth cardiac phenotyping in humans. Regional posterior wall myocardial dysfunction occurs during severe isoprenaline stress in mice. We have previously shown that regional posterior wall end-systolic transmural strain decreases after severe isoprenaline toxicity in mice. We hypothesize that STE can detect and further quantify these perturbations. Twenty-three mice underwent echocardiographic examination using the VEVO2100 system. Regional transmural radial strain and strain rate were calculated in both parasternal short-axis and parasternal long-axis cine loops using the VisualSonics VEVO 2100 velocity vector imaging (VVI) STE algorithm. Eight C57BL/6 mice underwent baseline echocardiographic examination using the VisualSonics VEVO 770 system, which can acquire >1,000 frames/s cine loops. In a parasternal short-axis cine loop, the heart was divided into six segments, and regional fractional wall thickening (FWT) was assessed manually. The same protocols were also performed 90 minutes post 400 mg/kg intraperitoneally isoprenaline. Regional myocardial FWT is uniform at baseline but increases significantly in anterolateral segments, whereas it decreases significantly in posterior segments (P < 0.05). A similar pattern is seen using the VVI algorithm although the variance is larger, and differences are smaller and fail to reach significance. VVI is less sensitive in detecting regional perturbations in myocardial function than manual tracing, possibly due to the low frame rate in the cine loops used. © 2012, Wiley Periodicals, Inc.

Effect of sympathetic nerves on composition and distensibility of cerebral arterioles in rats.

PubMed Central

Baumbach, G L; Heistad, D D; Siems, J E

1989-01-01

1. The goals of this study were to examine the effects of chronic sympathetic denervation on the mechanics and composition of cerebral arterioles in normotensive Wistar Kyoto rats (WKY) and stroke-prone spontaneously hypertensive rats (SHRSP). 2. We used an in vivo method to examine the mechanics of pial arterioles in 10- to 12-month-old, anaesthetized WKY and SHRSP that had undergone unilateral removal of the superior cervical ganglion at 1 month of age. Bilateral craniotomies were performed in each rat to expose pial arterioles in the innervated and denervated cerebral hemispheres. Arterioles were deactivated with EDTA. Incremental distensibility and stress-strain relationships were calculated from measurements of pial arteriolar pressure (servo null), diameter and cross-sectional area of the arteriolar wall. Point counting stereology was used to quantify volume density and cross-sectional area of individual components in the arteriolar wall. 3. Chronic sympathetic denervation reduced cross-sectional area of the arteriolar wall by 16 +/- 2% (mean +/- S.E. of mean; P less than 0.05) in WKY and 44 +/- 3% in SHRSP. During maximal dilatation with EDTA, incremental distensibility was reduced and the stress-strain curve was shifted to the left in denervated arterioles of SHRSP, but not WKY. These findings indicate that sympathetic denervation in SHRSP attenuates the development of hypertrophy in pial arterioles and reduces arteriolar distensibility. The ratio of non-distensible (collagen and basement membrane) to distensible (smooth muscle, elastin and endothelium) components was reduced in denervated arterioles in SHRSP, but not WKY. 4. Thus, sympathetic nerves have trophic effects on cerebral arterioles in WKY and, to a greater degree, in SHRSP. Sympathetic nerves also contribute to increases in distensibility of cerebral arterioles in SHRSP, but not WKY. The increase in arteriolar distensibility is accompanied by a disproportionate increase in the more compliant

Analysis of cerebral vessels dynamics using experimental data with missed segments

NASA Astrophysics Data System (ADS)

Pavlova, O. N.; Abdurashitov, A. S.; Ulanova, M. V.; Shihalov, G. M.; Semyachkina-Glushkovskaya, O. V.; Pavlov, A. N.

2018-04-01

Physiological signals often contain various bad segments that occur due to artifacts, failures of the recording equipment or varying experimental conditions. The related experimental data need to be preprocessed to avoid such parts of recordings. In the case of few bad segments, they can simply be removed from the signal and its analysis is further performed. However, when there are many extracted segments, the internal structure of the analyzed physiological process may be destroyed, and it is unclear whether such signal can be used in diagnostic-related studies. In this paper we address this problem for the case of cerebral vessels dynamics. We perform analysis of simulated data in order to reveal general features of quantifying scaling features of complex signals with distinct correlation properties and show that the effects of data loss are significantly different for experimental data with long-range correlations and anti-correlations. We conclude that the cerebral vessels dynamics is significantly less sensitive to missed data fragments as compared with signals with anti-correlated statistics.

Initial experience of a novel sheath guide for transbrachial coil embolization of cerebral aneurysms in the anterior cerebral circulation.

PubMed

Iwata, Tomonori; Mori, Takahisa; Tajiri, Hiroyuki; Miyazaki, Yuichi; Nakazaki, Masahito; Mizokami, Koji

2013-03-01

The transfemoral approach is a common technique for coil embolization of cerebral aneurysms in the anterior cerebral circulation. However, it is difficult to advance a guiding catheter into the carotid artery via the femoral route in patients with a tortuous aortic arch, an unfavorable supra-aortic takeoff, aortic diseases, or occlusion of the femoral artery. To report our initial experiences of coil embolization of cerebral aneurysms in the anterior cerebral circulation with a novel sheath guide for transbrachial carotid cannulation. A sheath guide designed specifically for transbrachial carotid cannulation was developed; transbrachial coil embolization for cerebral aneurysms began in May 2011. Included for analysis were patients who underwent transbrachial coil embolization for cerebral aneurysms in the anterior cerebral circulation from May 2011 to January 2012. Adjuvant techniques, angiographic results, procedural success, and periprocedural complications were investigated. Ten patients underwent transbrachial coil embolization of cerebral aneurysms in the anterior cerebral circulation. All procedures were successful using the brachial route. No periprocedural complications occurred. Patients were permitted to get seated immediately after coil embolization even during hemostasis. The sheath guide specifically designed for transbrachial carotid cannulation was useful for coil embolization of cerebral aneurysms in the anterior cerebral circulation.

Development and validation of a cerebral oximeter capable of absolute accuracy.

PubMed

MacLeod, David B; Ikeda, Keita; Vacchiano, Charles; Lobbestael, Aaron; Wahr, Joyce A; Shaw, Andrew D

2012-12-01

Cerebral oximetry may be a valuable monitor, but few validation data are available, and most report the change from baseline rather than absolute accuracy, which may be affected by individuals whose oximetric values are outside the expected range. The authors sought to develop and validate a cerebral oximeter capable of absolute accuracy. An in vivo research study. A university human physiology laboratory. Healthy human volunteers were enrolled in calibration and validation studies of 2 cerebral oximetric sensors, the Nonin 8000CA and 8004CA. The 8000CA validation study identified 5 individuals with atypical cerebral oxygenation values; their data were used to design the 8004CA sensor, which subsequently underwent calibration and validation. Volunteers were taken through a stepwise hypoxia protocol to a minimum saturation of peripheral oxygen. Arteriovenous saturation (70% jugular bulb venous saturation and 30% arterial saturation) at 6 hypoxic plateaus was used as the reference value for the cerebral oximeter. Absolute accuracy was defined using a combination of the bias and precision of the paired saturations (A(RMS)). In the validation study for the 8000CA sensor (n = 9, 106 plateaus), relative accuracy was an A(RMS) of 2.7, with an absolute accuracy of 8.1, meeting the criteria for a relative (trend) monitor, but not an absolute monitor. In the validation study for the 8004CA sensor (n = 11, 119 plateaus), the A(RMS) of the 8004CA was 4.1, meeting the prespecified success criterion of <5.0. The Nonin cerebral oximeter using the 8004CA sensor can provide absolute data on regional cerebral saturation compared with arteriovenous saturation, even in subjects previously shown to have values outside the normal population distribution curves. Copyright © 2012 Elsevier Inc. All rights reserved.

Quantifying the risk that marine debris poses to cetaceans in coastal waters of the 4-island region of Maui.

PubMed

Currie, Jens J; Stack, Stephanie H; McCordic, Jessica A; Kaufman, Gregory D

2017-08-15

Marine debris poses considerable threat to biodiversity and ecosystems and has been identified as a stressor for a variety of marine life. Here we present results from the first study quantifying the amount and type of debris accumulation in Maui leeward waters and relate this to cetacean distribution to identify areas where marine debris may present a higher threat. Transect surveys were conducted within the 4-island region of Maui, Hawai'i from April 1, 2013 to April 15, 2016. Debris was found in all areas of the study region with higher concentrations observed where the Au'au, Kealaikahiki, and Alalakeiki channels converge. The degree of overlap between debris and cetaceans varied among species but was largest for humpback whales, which account for the largest portion of reported entanglements in the 4-island region of Maui. Identifying areas of high debris-cetacean density overlap can facilitate species management and debris removal efforts. Copyright © 2017 Elsevier Ltd. All rights reserved.

Therapeutic interventions in cerebral palsy.

PubMed

Patel, Dilip R

2005-11-01

Various therapeutic interventions have been used in the management of children with cerebral palsy. Traditional physiotherapy and occupational therapy are widely used interventions and have been shown to be of benefit in the treatment of cerebral palsy. Evidence in support of the effectiveness of the neurodevelopmental treatment is equivocal at best. There is evidence to support the use and effectiveness of neuromuscular electrical stimulation in children with cerebral palsy. The effectiveness of many other interventions used in the treatment of cerebral palsy has not been clearly established based on well-controlled trials. These include: sensory integration, body-weight support treadmill training, conductive education, constraint-induced therapy, hyperbaric oxygen therapy, and the Vojta method. This article provides an overview of salient aspects of popular interventions used in the management of children with cerebral palsy.

Analyzing complex networks evolution through Information Theory quantifiers

NASA Astrophysics Data System (ADS)

Carpi, Laura C.; Rosso, Osvaldo A.; Saco, Patricia M.; Ravetti, Martín Gómez

2011-01-01

A methodology to analyze dynamical changes in complex networks based on Information Theory quantifiers is proposed. The square root of the Jensen-Shannon divergence, a measure of dissimilarity between two probability distributions, and the MPR Statistical Complexity are used to quantify states in the network evolution process. Three cases are analyzed, the Watts-Strogatz model, a gene network during the progression of Alzheimer's disease and a climate network for the Tropical Pacific region to study the El Niño/Southern Oscillation (ENSO) dynamic. We find that the proposed quantifiers are able not only to capture changes in the dynamics of the processes but also to quantify and compare states in their evolution.

Cerebral Palsy Litigation

PubMed Central

Sartwelle, Thomas P.

2015-01-01

The cardinal driver of cerebral palsy litigation is electronic fetal monitoring, which has continued unabated for 40 years. Electronic fetal monitoring, however, is based on 19th-century childbirth myths, a virtually nonexistent scientific foundation, and has a false positive rate exceeding 99%. It has not affected the incidence of cerebral palsy. Electronic fetal monitoring has, however, increased the cesarian section rate, with the expected increase in mortality and morbidity risks to mothers and babies alike. This article explains why electronic fetal monitoring remains endorsed as efficacious in the worlds’ labor rooms and courtrooms despite being such a feeble medical modality. It also reviews the reasons professional organizations have failed to condemn the use of electronic fetal monitoring in courtrooms. The failures of tort reform, special cerebral palsy courts, and damage limits to stem the escalating litigation are discussed. Finally, the authors propose using a currently available evidence rule—the Daubert doctrine that excludes “junk science” from the courtroom—as the beginning of the end to cerebral palsy litigation and electronic fetal monitoring’s 40-year masquerade as science. PMID:25183322

Quantifying the test-retest reliability of cerebral blood flow measurements in a clinical model of on-going post-surgical pain: A study using pseudo-continuous arterial spin labelling.

PubMed

Hodkinson, Duncan J; Krause, Kristina; Khawaja, Nadine; Renton, Tara F; Huggins, John P; Vennart, William; Thacker, Michael A; Mehta, Mitul A; Zelaya, Fernando O; Williams, Steven C R; Howard, Matthew A

2013-01-01

Arterial spin labelling (ASL) is increasingly being applied to study the cerebral response to pain in both experimental human models and patients with persistent pain. Despite its advantages, scanning time and reliability remain important issues in the clinical applicability of ASL. Here we present the test-retest analysis of concurrent pseudo-continuous ASL (pCASL) and visual analogue scale (VAS), in a clinical model of on-going pain following third molar extraction (TME). Using ICC performance measures, we were able to quantify the reliability of the post-surgical pain state and ΔCBF (change in CBF), both at the group and individual case level. Within-subject, the inter- and intra-session reliability of the post-surgical pain state was ranked good-to-excellent (ICC > 0.6) across both pCASL and VAS modalities. The parameter ΔCBF (change in CBF between pre- and post-surgical states) performed reliably (ICC > 0.4), provided that a single baseline condition (or the mean of more than one baseline) was used for subtraction. Between-subjects, the pCASL measurements in the post-surgical pain state and ΔCBF were both characterised as reliable (ICC > 0.4). However, the subjective VAS pain ratings demonstrated a significant contribution of pain state variability, which suggests diminished utility for interindividual comparisons. These analyses indicate that the pCASL imaging technique has considerable potential for the comparison of within- and between-subjects differences associated with pain-induced state changes and baseline differences in regional CBF. They also suggest that differences in baseline perfusion and functional lateralisation characteristics may play an important role in the overall reliability of the estimated changes in CBF. Repeated measures designs have the important advantage that they provide good reliability for comparing condition effects because all sources of variability between subjects are excluded from the experimental error. The ability to

Neurodevelopmental Outcomes Following Regional Cerebral Perfusion with Neuromonitoring for Neonatal Aortic Arch Reconstruction

PubMed Central

Andropoulos, Dean B.; Easley, R. Blaine; Brady, Ken; McKenzie, E. Dean; Heinle, Jeffrey S.; Dickerson, Heather A.; Shekerdemian, Lara S.; Meador, Marcie; Eisenman, Carol; Hunter, Jill V.; Turcich, Marie; Voigt, Robert G.; Fraser, Charles D.

2013-01-01

Background In this study we report magnetic resonance imaging (MRI) brain injury, and 12 month neurodevelopmental outcomes, when regional cerebral perfusion (RCP) is utilized for neonatal aortic arch reconstruction. Methods Fifty seven neonates receiving RCP during aortic arch reconstruction were enrolled in a prospective outcome study. RCP flows were determined by near-infrared spectroscopy and transcranial Doppler monitoring. Brain MRI were performed preoperatively and 7 days postoperatively. Bayley Scales of Infant Development III was performed at 12 months. Results Mean RCP time was 71 ± 28 minutes (range 5–121), mean flow 56.6 ± 10.6 ml/kg/min. New postoperative MRI brain injury was seen in 40% of patients. For 35 RCP patients at age 12 months, mean Bayley III composite standard scores were: Cognitive = 100.1 ± 14.6,(range 75–125); Language = 87.2 ± 15.0, (range 62–132); Motor = 87.9 ± 16.8, (range 58–121).Increasing duration of RCP was not associated with adverse neurodevelopmental outcomes. Conclusions Neonatal aortic arch repair with RCP utilizing a neuromonitoring strategy results in 12-month cognitive outcomes that are at reference population norms; language and motor outcomes are lower than the reference population norms by 0.8–0.9 standard deviation. This largest RCP group with neurodevelopmental outcomes published to date demonstrates that this technique is effective and safe in supporting the brain during neonatal aortic arch reconstruction. PMID:22766302

Cerebral hemodynamic changes of mild traumatic brain injury at the acute stage.

PubMed

Doshi, Hardik; Wiseman, Natalie; Liu, Jun; Wang, Wentao; Welch, Robert D; O'Neil, Brian J; Zuk, Conor; Wang, Xiao; Mika, Valerie; Szaflarski, Jerzy P; Haacke, E Mark; Kou, Zhifeng

2015-01-01

Mild traumatic brain injury (mTBI) is a significant public health care burden in the United States. However, we lack a detailed understanding of the pathophysiology following mTBI and its relation to symptoms and recovery. With advanced magnetic resonance imaging (MRI), we can investigate brain perfusion and oxygenation in regions known to be implicated in symptoms, including cortical gray matter and subcortical structures. In this study, we assessed 14 mTBI patients and 18 controls with susceptibility weighted imaging and mapping (SWIM) for blood oxygenation quantification. In addition to SWIM, 7 patients and 12 controls had cerebral perfusion measured with arterial spin labeling (ASL). We found increases in regional cerebral blood flow (CBF) in the left striatum, and in frontal and occipital lobes in patients as compared to controls (p = 0.01, 0.03, 0.03 respectively). We also found decreases in venous susceptibility, indicating increases in venous oxygenation, in the left thalamostriate vein and right basal vein of Rosenthal (p = 0.04 in both). mTBI patients had significantly lower delayed recall scores on the standardized assessment of concussion, but neither susceptibility nor CBF measures were found to correlate with symptoms as assessed by neuropsychological testing. The increased CBF combined with increased venous oxygenation suggests an increase in cerebral blood flow that exceeds the oxygen demand of the tissue, in contrast to the regional hypoxia seen in more severe TBI. This may represent a neuroprotective response following mTBI, which warrants further investigation.

Cerebral amyloid angiopathy increases susceptibility to infarction after focal cerebral ischemia in Tg2576 mice.

PubMed

Milner, Eric; Zhou, Meng-Liang; Johnson, Andrew W; Vellimana, Ananth K; Greenberg, Jacob K; Holtzman, David M; Han, Byung Hee; Zipfel, Gregory J

2014-10-01

We and others have shown that soluble amyloid β-peptide (Aβ) and cerebral amyloid angiopathy (CAA) cause significant cerebrovascular dysfunction in mutant amyloid precursor protein (APP) mice, and that these deficits are greater in aged APP mice having CAA compared with young APP mice lacking CAA. Amyloid β-peptide in young APP mice also increases infarction after focal cerebral ischemia, but the impact of CAA on ischemic brain injury is unknown. To determine this, we assessed cerebrovascular reactivity, cerebral blood flow (CBF), and extent of infarction and neurological deficits after transient middle cerebral artery occlusion in aged APP mice having extensive CAA versus young APP mice lacking CAA (and aged-matched littermate controls). We found that aged APP mice have more severe cerebrovascular dysfunction that is CAA dependent, have greater CBF compromise during and immediately after middle cerebral artery occlusion, and develop larger infarctions after middle cerebral artery occlusion. These data indicate CAA induces a more severe form of cerebrovascular dysfunction than amyloid β-peptide alone, leading to intra- and postischemic CBF deficits that ultimately exacerbate cerebral infarction. Our results shed mechanistic light on human studies identifying CAA as an independent risk factor for ischemic brain injury. © 2014 American Heart Association, Inc.

The habenula and iron metabolism in cerebral mouse models of multiple sclerosis

PubMed Central

Sands, Scott A.; Tsau, Sheila; LeVine, Steven M.

2015-01-01

Iron accumulates in the CNS of patients with multiple sclerosis, but our understanding of the mechanism accounting for this accumulation is unclear. Mouse models of cerebral experimental autoimmune encephalomyelitis (EAE) in C57BL/6 and SJL mice were used together with a histochemical stain for iron and immunohistochemical stains for transferrin receptor, synaptophysin, iron regulatory protein 1 (IRP1) and/or IRP2 to investigate the role of disease activity on CNS iron metabolism. The expression of transferrin receptor, but not IRP1 or IRP2, increased in the medial habenula, which is adjacent to the third ventricle, in response to both types of cerebral EAE. In the habenula, the elevated expression of transferrin receptor in C57BL/6 mice with cerebral EAE was generally restricted to the medial habenula while the expression in SJL mice with cerebral EAE was more diffusely expressed. Iron levels were increased in all regions of the habenula in C57BL/6 mice with cerebral EAE, and in the medial and medial lateral but not the lateral habenula in SJL mice with cerebral EAE. Synaptophysin, which has been observed previously in endocytic vesicles together with the transferrin receptor, was concentrated at the medial habenula, but its levels did not increase with disease in C57BL/6 mice with cerebral EAE. Our results support the model that the medial habenula responds to disease activity by upregulating transferrin receptor to facilitate the movement of iron into the brain from the third ventricle, raising the possibility that a similar mechanism accounts for iron accumulation in deep gray matter structures in patients with multiple sclerosis. PMID:26362814

Effects of hyperbaric oxygen on intracranial pressure and cerebral blood flow in experimental cerebral oedema1

PubMed Central

Miller, J. D.; Ledingham, I. McA.; Jennett, W. B.

1970-01-01

Increased intracranial pressure was induced in anaesthetized dogs by application of liquid nitrogen to the dura mater. Intracranial pressure and cerebral blood flow were measured, together with arterial blood pressure and arterial and cerebral venous blood gases. Carbon dioxide was administered intermittently to test the responsiveness of the cerebral circulation, and hyperbaric oxygen was delivered at intervals in a walk-in hyperbaric chamber, pressurized to two atmospheres absolute. Hyperbaric oxygen caused a 30% reduction of intracranial pressure and a 19% reduction of cerebral blood flow in the absence of changes in arterial PCO2 or blood pressure, but only as long as administration of carbon dioxide caused an increase in both intracranial pressure and cerebral blood flow. When carbon dioxide failed to influence intracranial pressure or cerebral blood flow then hyperbaric oxygen had no effect. This unresponsive state was reached at high levels of intracranial pressure. Images PMID:5497875

[A case of severe asthma exacerbation complicated with cerebral edema and diffuse multiple cerebral micro-bleeds].

PubMed

Ohkura, Noriyuki; Fujimura, Masaki; Sakai, Asao; Fujita, Kentaro; Katayama, Nobuyuki

2009-08-01

A 36-year-old woman was admitted to the Intensive Care Unit for the treatment of severe asthma exacerbation. Her condition of asthma improved with systemic glucocorticosteroids, inhaled beta2-agonist, intravenous theophylline and inhaled anesthesia (isoflurane) under mechanical ventilation. Her consciousness was disturbed even after terminating isoflurane. Brain CT and MRI scan showed cerebral edema and diffuse multiple cerebral micro-bleeds. Glyceol, a hyperosmotic diuretic solution consisting of 10% glycerol and 5% fructose in saline, was administered to decrease cerebral edema. Her consciousness disturbance gradually recovered. Cerebral edema and hemorrhage improved. On the 69th hospital day, she was discharged from hospital without sequelae. This case is a rare one in which severe asthma exacerbation was complicated with cerebral edema and diffuse multiple cerebral hemorrhage. Inhaled anesthesia for asthma exacerbation should be used carefully to avoid delay of diagnosis of central nervous system complications.

Influence of beach chair position on cerebral oxygen saturation: a comparison of INVOS and FORE-SIGHT cerebral oximeter.

PubMed

Closhen, Dorothea; Berres, Manfred; Werner, Christian; Engelhard, Kristin; Schramm, Patrick

2013-10-01

Although beach chair position (BCP) is frequently used for shoulder surgery, a potentially detrimental influence on cerebral oxygenation is discussed. Therefore, the present study investigated changes in regional cerebral oxygen saturation (rSO2/StO2) during BCP comparing 2 different devices for near-infrared spectroscopy measurement. Data were collected in 35 patients undergoing shoulder surgery in BCP and compared with a control group of 35 awake volunteers. The rSO2/StO2 was assessed using INVOS and FORE-SIGHT monitors. Mean arterial blood pressure (MAP), peripheral oxygen saturation (SpO2), PeCO2, FiO2, end-tidal sevoflurane concentration, and rSO2/StO2 were measured before positioning, during BCP, and in supine position after surgery. A decrease in rSO2/StO2 could be observed after BCP (INVOS: 76.1% supine vs. 66.7% BCP, P<0.001; FORE-SIGHT: 78.6% supine, 66.1% BCP, P<0.001), which was reversible in supine position. This decrease correlated with MAP during BCP, while in supine position no correlation was detected. In control group BCP did not influence rSO2/StO2. Changes detected with INVOS or FORE-SIGHT cerebral oximeter did not differ. BCP is associated with a decrease in rSO2/StO2 of 10% in anesthetized patients, which is reversible after repositioning. No changes occurred in supine position under general anesthesia as well as in awake subjects in BCP. This underlines the assumption that vasodilation by anesthetics in combination with BCP evoke a drop in rSO2/StO2. A strict hemodynamic management may be necessary to prevent desaturation events. Despite different technology used by the devices, the results of INVOS and FORE-SIGHT cerebral oximeters are comparable.

[Assessment of motor and sensory pathways of the brain using diffusion-tensor tractography in children with cerebral palsy].

PubMed

Memedyarov, A M; Namazova-Baranova, L S; Ermolina, Y V; Anikin, A V; Maslova, O I; Karkashadze, M Z; Klochkova, O A

2014-01-01

Diffusion tensor tractography--a new method of magnetic resonance imaging, that allows to visualize the pathways of the brain and to study their structural-functional state. The authors investigated the changes in motor and sensory pathways of brain in children with cerebral palsy using routine magnetic resonance imaging and diffusion-tensor tractography. The main group consisted of 26 patients with various forms of cerebral palsy and the comparison group was 25 people with normal psychomotor development (aged 2 to 6 years) and MR-picture of the brain. Magnetic resonance imaging was performed on the scanner with the induction of a magnetic field of 1,5 Tesla. Coefficients of fractional anisotropy and average diffusion coefficient estimated in regions of the brain containing the motor and sensory pathways: precentral gyrus, posterior limb of the internal capsule, thalamus, posterior thalamic radiation and corpus callosum. Statistically significant differences (p < 0.05) values of fractional anisotropy and average diffusion coefficient in patients with cerebral palsy in relation to the comparison group. All investigated regions, the coefficients of fractional anisotropy in children with cerebral palsy were significantly lower, and the average diffusion coefficient, respectively, higher. These changes indicate a lower degree of ordering of the white matter tracts associated with damage and subsequent development of gliosis of varying severity in children with cerebral palsy. It is shown that microstructural damage localized in both motor and sensory tracts that plays a leading role in the development of the clinical picture of cerebral palsy.

Estimates of segregation and overlap of functional connectivity networks in the human cerebral cortex.

PubMed

Yeo, B T Thomas; Krienen, Fenna M; Chee, Michael W L; Buckner, Randy L

2014-03-01

The organization of the human cerebral cortex has recently been explored using techniques for parcellating the cortex into distinct functionally coupled networks. The divergent and convergent nature of cortico-cortical anatomic connections suggests the need to consider the possibility of regions belonging to multiple networks and hierarchies among networks. Here we applied the Latent Dirichlet Allocation (LDA) model and spatial independent component analysis (ICA) to solve for functionally coupled cerebral networks without assuming that cortical regions belong to a single network. Data analyzed included 1000 subjects from the Brain Genomics Superstruct Project (GSP) and 12 high quality individual subjects from the Human Connectome Project (HCP). The organization of the cerebral cortex was similar regardless of whether a winner-take-all approach or the more relaxed constraints of LDA (or ICA) were imposed. This suggests that large-scale networks may function as partially isolated modules. Several notable interactions among networks were uncovered by the LDA analysis. Many association regions belong to at least two networks, while somatomotor and early visual cortices are especially isolated. As examples of interaction, the precuneus, lateral temporal cortex, medial prefrontal cortex and posterior parietal cortex participate in multiple paralimbic networks that together comprise subsystems of the default network. In addition, regions at or near the frontal eye field and human lateral intraparietal area homologue participate in multiple hierarchically organized networks. These observations were replicated in both datasets and could be detected (and replicated) in individual subjects from the HCP. © 2013.

Estimates of Segregation and Overlap of Functional Connectivity Networks in the Human Cerebral Cortex

PubMed Central

Yeo, BT Thomas; Krienen, Fenna M; Chee, Michael WL; Buckner, Randy L

2014-01-01

The organization of the human cerebral cortex has recently been explored using techniques for parcellating the cortex into distinct functionally coupled networks. The divergent and convergent nature of cortico-cortical anatomic connections suggests the need to consider the possibility of regions belonging to multiple networks and hierarchies among networks. Here we applied the Latent Dirichlet Allocation (LDA) model and spatial independent component analysis (ICA) to solve for functionally coupled cerebral networks without assuming that cortical regions belong to a single network. Data analyzed included 1,000 subjects from the Brain Genomics Superstruct Project (GSP) and 12 high quality individual subjects from the Human Connectome Project (HCP). The organization of the cerebral cortex was similar regardless of whether a winner-take-all approach or the more relaxed constraints of LDA (or ICA) were imposed. This suggests that large-scale networks may function as partially isolated modules. Several notable interactions among networks were uncovered by the LDA analysis. Many association regions belong to at least two networks, while somatomotor and early visual cortices are especially isolated. As examples of interaction, the precuneus, lateral temporal cortex, medial prefrontal cortex and posterior parietal cortex participate in multiple paralimbic networks that together comprise subsystems of the default network. In addition, regions at or near the frontal eye field and human lateral intraparietal area homologue participate in multiple hierarchically organized networks. These observations were replicated in both datasets and could be detected (and replicated) in individual subjects from the HCP. PMID:24185018

Low nocturnal blood pressure is associated with reduced cerebral blood flow in the cohort “Men born in 1914”

PubMed Central

Reinprecht, Faina; Axelsson, Johan; Siennicki-Lantz, Arkadiusz; Elmståhl, Sölve

2008-01-01

BACKGROUND: “Men born in 1914” is a population-based cohort study of the epidemiology of cardiovascular and cerebral disease. Little is known about how diurnal variation in blood pressure (BP) levels influence cerebral perfusion in very elderly populations. OBJECTIVES: To study the association between systolic (SBP) and diastolic BP (DBP) levels, during the day and at night, expressed through 24 h ambulatory BP monitoring (ABPM) and regional cerebral blood flow (rCBF) disturbances. METHODS: A cross-sectional study from a population-based cohort of 108 men 81 years of age (born in 1914) was performed in an out-patient university clinic. Cerebral blood flow measurements using 99mTc-hexamethylpropyleneamine oxime single photon emission computed tomography and 24 h ABPM were performed. Eleven men were excluded due to incomplete ABPM data. RESULTS: Mean DBP at night for each tertile was correlated to rCBF for the medial temporal right (P=0.012) and left (P=0.039) regions. Also, DBP during the day was correlated to the medial temporal right region (P=0.025). When analyses were stratified for DBP during the day, subjects with high DBP during the day (greater than 70 mmHg) showed a stronger association between low medial temporal right rCBF and low mean DBP at night (r=0.32, P=0.009) compared with subjects who had a lower daytime DBP. A corresponding positive correlation was noted for the medial temporal left region and daytime SBP, whereas a negative correlation was noted for frontal left region blood flow and SBP at night. CONCLUSIONS: A significant association was seen between low BP levels, especially at night, and rCBF in subjects with otherwise normal daytime DBP that may indicate a risk for nocturnal cerebral ischemia. PMID:22477391

Quantifying loopy network architectures.

PubMed

Katifori, Eleni; Magnasco, Marcelo O

2012-01-01

Biology presents many examples of planar distribution and structural networks having dense sets of closed loops. An archetype of this form of network organization is the vasculature of dicotyledonous leaves, which showcases a hierarchically-nested architecture containing closed loops at many different levels. Although a number of approaches have been proposed to measure aspects of the structure of such networks, a robust metric to quantify their hierarchical organization is still lacking. We present an algorithmic framework, the hierarchical loop decomposition, that allows mapping loopy networks to binary trees, preserving in the connectivity of the trees the architecture of the original graph. We apply this framework to investigate computer generated graphs, such as artificial models and optimal distribution networks, as well as natural graphs extracted from digitized images of dicotyledonous leaves and vasculature of rat cerebral neocortex. We calculate various metrics based on the asymmetry, the cumulative size distribution and the Strahler bifurcation ratios of the corresponding trees and discuss the relationship of these quantities to the architectural organization of the original graphs. This algorithmic framework decouples the geometric information (exact location of edges and nodes) from the metric topology (connectivity and edge weight) and it ultimately allows us to perform a quantitative statistical comparison between predictions of theoretical models and naturally occurring loopy graphs.

Neonatal risk factors for cerebral palsy in very preterm babies: case-control study.

PubMed Central

Murphy, D. J.; Hope, P. L.; Johnson, A.

1997-01-01

OBJECTIVE: To identify neonatal risk factors for cerebral palsy among very preterm babies and in particular the associations independent of the coexistence of antenatal and intrapartum factors. DESIGN: Case-control study. SETTING: Oxford health region. SUBJECTS: Singleton babies born between 1984 and 1990 at less than 32 weeks' gestation who survived to discharge from hospital: 59 with cerebral palsy and 234 randomly selected controls without cerebral palsy. MAIN OUTCOME MEASURES: Adverse neonatal factors expressed as odds ratios and 95% confidence intervals. RESULTS: Factors associated with an increased risk of cerebral palsy after adjustment for gestational age and the presence of previously identified antenatal and intrapartum risk factors were patent ductus arteriosus (odds ratio 2.3; 95% confidence interval 1.2 to 4.5), hypotension (2.3; 1.3 to 4.7), blood transfusion (4.8; 2.5 to 9.3), prolonged ventilation (4.8; 2.5 to 9.0), pneumothorax (3.5; 1.6 to 7.6), sepsis (3.6; 1.8 to 7.4), hyponatraemia (7.9; 2.1 to 29.6) and total parenteral nutrition (5.5; 2.8 to 10.5). Seizures were associated with an increased risk of cerebral palsy (10.0; 4.1 to 24.7), as were parenchymal damage (32; 12.4 to 84.4) and appreciable ventricular dilatation (5.4; 3.0 to 9.8) detected by cerebral ultrasound. CONCLUSION: A reduction in the rate of cerebral palsy in very preterm babies requires an integrated approach to management throughout the antenatal, intrapartum, and neonatal periods. PMID:9040385

Cerebral Palsy (For Kids)

MedlinePlus

... Staying Safe Videos for Educators Search English Español Cerebral Palsy KidsHealth / For Kids / Cerebral Palsy What's in this ... the things that kids do every day. What's CP? Some kids with CP use wheelchairs and others ...

Carnosine reverses the aging-induced down regulation of brain regional serotonergic system.

PubMed

Banerjee, Soumyabrata; Ghosh, Tushar K; Poddar, Mrinal K

2015-12-01

The purpose of the present investigation was to study the role of carnosine, an endogenous dipeptide biomolecule, on brain regional (cerebral cortex, hippocampus, hypothalamus and pons-medulla) serotonergic system during aging. Results showed an aging-induced brain region specific significant (a) increase in Trp (except cerebral cortex) and their 5-HIAA steady state level with an increase in their 5-HIAA accumulation and declination, (b) decrease in their both 5-HT steady state level and 5-HT accumulation (except cerebral cortex). A significant decrease in brain regional 5-HT/Trp ratio (except cerebral cortex) and increase in 5-HIAA/5-HT ratio were also observed during aging. Carnosine at lower dosages (0.5-1.0μg/Kg/day, i.t. for 21 consecutive days) didn't produce any significant response in any of the brain regions, but higher dosages (2.0-2.5μg/Kg/day, i.t. for 21 consecutive days) showed a significant response on those aging-induced brain regional serotonergic parameters. The treatment with carnosine (2.0μg/Kg/day, i.t. for 21 consecutive days), attenuated these brain regional aging-induced serotonergic parameters and restored towards their basal levels that observed in 4 months young control rats. These results suggest that carnosine attenuates and restores the aging-induced brain regional down regulation of serotonergic system towards that observed in young rats' brain regions. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Longitudinal Cerebral Blood Flow Changes during Speech in Hereditary Ataxia

ERIC Educational Resources Information Center

Sidtis, John J.; Strother, Stephen C.; Naoum, Ansam; Rottenberg, David A.; Gomez, Christopher

2010-01-01

The hereditary ataxias constitute a group of degenerative diseases that progress over years or decades. With principal pathology involving the cerebellum, dysarthria is an early feature of many of the ataxias. Positron emission tomography was used to study regional cerebral blood flow changes during speech production over a 21 month period in a…

Application of positron emission tomography to determine cerebral glucose utilization in conscious infant monkeys.

PubMed

Moore, A H; Cherry, S R; Pollack, D B; Hovda, D A; Phelps, M E

1999-05-01

Cerebral glucose metabolism has been used as a marker of cerebral maturation and neuroplasticity. In studies addressing these issues in young non-human primates, investigators have used positron emission tomography (PET) and [18F]2-fluoro-2-deoxy-D-glucose (FDG) to calculate local cerebral metabolic rates of glucose (1CMRG1c). Unfortunately, these values were influenced by anesthesia. In order to avoid this confounding factor, we have established a method that permits reliable measurements in young conscious vervet monkeys using FDG-PET. Immature animals remained in a conscious, resting state during the initial 42 min of FDG uptake as they were allowed to cling to their anesthetized mothers. After FDG uptake, animals were anesthetized and placed in the PET scanner with data acquisition beginning at 60 min post-FDG injection. FDG image sets consisted of 30 planes separated by 1.69 mm, parameters sufficient to image the entire monkey brain. Our method of region-of-interest (ROI) analysis was assessed within and between raters and demonstrated high reliability (P < 0.001). To illustrate that our method was sensitive to developmental changes in cerebral glucose metabolism, quantitative studies of young conscious monkeys revealed that infant monkeys 6-8 months of age exhibited significantly higher 1CMRG1c values (P < 0.05) in all regions examined, except sensorimotor cortex and thalamus, compared to monkeys younger than 4 months of age. This method provided high resolution images and 1CMRG1c values that were reliable within age group. These results support the application of FDG-PET to investigate questions related to cerebral glucose metabolism in young conscious non-human primates.

Molecular pathophysiology of cerebral edema

PubMed Central

Gerzanich, Volodymyr; Simard, J Marc

2015-01-01

Advancements in molecular biology have led to a greater understanding of the individual proteins responsible for generating cerebral edema. In large part, the study of cerebral edema is the study of maladaptive ion transport. Following acute CNS injury, cells of the neurovascular unit, particularly brain endothelial cells and astrocytes, undergo a program of pre- and post-transcriptional changes in the activity of ion channels and transporters. These changes can result in maladaptive ion transport and the generation of abnormal osmotic forces that, ultimately, manifest as cerebral edema. This review discusses past models and current knowledge regarding the molecular and cellular pathophysiology of cerebral edema. PMID:26661240

Traumatic brain injury causes long-term behavioral changes related to region-specific increases of cerebral blood flow.

PubMed

Pöttker, Bruno; Stöber, Franziska; Hummel, Regina; Angenstein, Frank; Radyushkin, Konstantin; Goldschmidt, Jürgen; Schäfer, Michael K E

2017-12-01

Traumatic brain injury (TBI) is a leading cause of disability and death and survivors often suffer from long-lasting motor impairment, cognitive deficits, anxiety disorders and epilepsy. Few experimental studies have investigated long-term sequelae after TBI and relations between behavioral changes and neural activity patterns remain elusive. We examined these issues in a murine model of TBI combining histology, behavioral analyses and single-photon emission computed tomography (SPECT) imaging of regional cerebral blood flow (CBF) as a proxy for neural activity. Adult C57Bl/6N mice were subjected to unilateral cortical impact injury and investigated at early (15-57 days after lesion, dal) and late (184-225 dal) post-traumatic time points. TBI caused pronounced tissue loss of the parietal cortex and subcortical structures and enduring neurological deficits. Marked perilesional astro- and microgliosis was found at 57 dal and declined at 225 dal. Motor and gait pattern deficits occurred at early time points after TBI and improved over the time. In contrast, impaired performance in the Morris water maze test and decreased anxiety-like behavior persisted together with an increased susceptibility to pentylenetetrazole-induced seizures suggesting alterations in neural activity patterns. Accordingly, SPECT imaging of CBF indicated asymmetric hemispheric baseline neural activity patterns. In the ipsilateral hemisphere, increased baseline neural activity was found in the amygdala. In the contralateral hemisphere, homotopic to the structural brain damage, the hippocampus and distinct cortex regions displayed increased baseline neural activity. Thus, regionally elevated CBF along with behavioral alterations indicate that increased neural activity is critically involved in the long-lasting consequences of TBI.

Symptomatic Cerebral Vasospasm and Delayed Cerebral Ischemia Following Transsphenoidal Resection of a Craniopharyngioma.

PubMed

Ricarte, Irapuá Ferreira; Funchal, Bruno F; Miranda Alves, Maramélia A; Gomes, Daniela L; Valiente, Raul A; Carvalho, Flávio A; Silva, Gisele S

2015-09-01

Vasospasm has been rarely described as a complication associated with craniopharyngioma surgery. Herein we describe a patient who developed symptomatic vasospasm and delayed cerebral ischemia after transsphenoidal surgery for a craniopharyngioma. A 67-year-old woman became drowsy 2 weeks after a transsphenoidal resection of a craniopharyngioma. A head computed tomography (CT) was unremarkable except for postoperative findings. Electroencephalogram and laboratory studies were within the normal limits. A repeated CT scan 48 hours after the initial symptoms showed bilateral infarcts in the territory of the anterior cerebral arteries (ACA). Transcranial Doppler (TCD) showed increased blood flow velocities in both anterior cerebral arteries (169 cm/second in the left ACA and 145 cm/second in the right ACA) and right middle cerebral artery (164 cm/second) compatible with vasospasm. A CT angiography confirmed the findings. She was treated with induced hypertension and her level of consciousness improved. TCD velocities normalized after 2 weeks. Cerebral vasospasm should be considered in the differential diagnosis of patients with altered neurologic status in the postoperative period following a craniopharyngioma resection. Copyright © 2015 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Neuroprotective effects of water-soluble Ganoderma lucidum polysaccharides on cerebral ischemic injury in rats.

PubMed

Zhou, Zi-Yi; Tang, Yu-Ping; Xiang, Jun; Wua, Pin; Jin, Hui-Ming; Wang, Zhong; Mori, Masao; Cai, Ding-Fang

2010-08-19

To investigate the neuroprotective effects of water-soluble Ganoderma lucidum polysaccharides (GLPS) on cerebral ischemic injury in rats, and to explore the involved mechanisms. Two models [middle cerebral artery occlusion (MCAO) in Sprague-Dawley (SD) rats and oxygen and glucose deprivation (OGD) in primary cultured rat cortical neurons] were employed to mimic ischemia-reperfusion (I/R) damage, in vivo and in vitro, respectively. Cerebral infarct area was measured by tetrazolium staining, and neurological functional deficits were assessed at 24h after I/R. Neuronal apoptosis was studied by Nissl staining and DNA fragmentation assay. Neuronal injury was assessed by morphological examination using phase-contrast microscopy and quantified by measuring the amount of lactate dehydrogenase (LDH) leakage, cell viability was measured by sodium 3'-1- (phenylaminocarbonyl)-3, 4-tetrazolium-bis (4-methoxy-6-nitro) benzene sulfonic acid (XTT) reduction. Neuronal apoptosis was determined by flow cytometry, and electron microscopy was used to study morphological changes of neurons. Caspase-3, -8 and -9 activation and Bcl-2, Bax protein expression were determined by western blot analysis. Oral administration of GLPS (100, 200 and 400mg/kg) significantly reduced cerebral infarct area, attenuated neurological functional deficits, and reduced neuronal apoptosis in ischemic cortex. In OGD model, GLSP (0.1, 1 and 10 microg/ml) effectively reduced neuronal cell death and relieved cell injury. Moreover, GLPS decreased the percentage of apoptotic neurons, relieved neuronal morphological damage, suppressed overexpression of active caspases-3, -8 and -9 and Bax, and inhibited the reduction of Bcl-2 expression. Our findings indicate that GLPS protects against cerebral ischemic injury by inhibiting apoptosis by downregulating caspase-3 activation and modulating the Bcl-2/Bax ratio. (c) 2010 Elsevier Ireland Ltd. All rights reserved.

Multimodal Pressure-Flow Analysis: Application of Hilbert Huang Transform in Cerebral Blood Flow Regulation

NASA Astrophysics Data System (ADS)

Lo, Men-Tzung; Hu, Kun; Liu, Yanhui; Peng, C.-K.; Novak, Vera

2008-12-01

Quantification of nonlinear interactions between two nonstationary signals presents a computational challenge in different research fields, especially for assessments of physiological systems. Traditional approaches that are based on theories of stationary signals cannot resolve nonstationarity-related issues and, thus, cannot reliably assess nonlinear interactions in physiological systems. In this review we discuss a new technique called multimodal pressure flow (MMPF) method that utilizes Hilbert-Huang transformation to quantify interaction between nonstationary cerebral blood flow velocity (BFV) and blood pressure (BP) for the assessment of dynamic cerebral autoregulation (CA). CA is an important mechanism responsible for controlling cerebral blood flow in responses to fluctuations in systemic BP within a few heart-beats. The MMPF analysis decomposes BP and BFV signals into multiple empirical modes adaptively so that the fluctuations caused by a specific physiologic process can be represented in a corresponding empirical mode. Using this technique, we showed that dynamic CA can be characterized by specific phase delays between the decomposed BP and BFV oscillations, and that the phase shifts are significantly reduced in hypertensive, diabetics and stroke subjects with impaired CA. Additionally, the new technique can reliably assess CA using both induced BP/BFV oscillations during clinical tests and spontaneous BP/BFV fluctuations during resting conditions.

Quantifying sex, race, and age specific differences in bone microstructure requires measurement of anatomically equivalent regions.

PubMed

Ghasem-Zadeh, Ali; Burghardt, Andrew; Wang, Xiao-Fang; Iuliano, Sandra; Bonaretti, Serena; Bui, Minh; Zebaze, Roger; Seeman, Ego

2017-08-01

Individuals differ in forearm length. As microstructure differs along the radius, we hypothesized that errors may occur when sexual and racial dimorphisms are quantified at a fixed distance from the radio-carpal joint. Microstructure was quantified ex vivo in 18 cadaveric radii using high resolution peripheral quantitative computed tomography and in vivo in 158 Asian and Caucasian women and men at a fixed region of interest (ROI), a corrected ROI positioned at 4.5-6% of forearm length and using the fixed ROI adjusted for cross sectional area (CSA), forearm length or height. Secular effects of age were assessed by comparing 38 younger and 33 older women. Ex vivo, similar amounts of bone mass fashioned adjacent cross sections. Larger distal cross sections had thinner porous cortices of lower matrix mineral density (MMD), a larger medullary CSA and higher trabecular density. Smaller proximal cross-sections had thicker less porous cortices of higher MMD, a small medullary canal with little trabecular bone. Taller persons had more distally positioned fixed ROIs which moved proximally when corrected. Shorter persons had more proximally positioned fixed ROIs which moved distally when corrected, so dimorphisms lessened. In the corrected ROIs, in Caucasians, women had 0.6 SD higher porosity and 0.6 SD lower trabecular density than men (p<0.01). In Asians, women had 0.25 SD higher porosity (NS) and 0.5 SD lower trabecular density than men (p<0.05). In women, Asians had 0.8 SD lower porosity and 0.3 SD higher trabecular density than Caucasians (p<0.01). In men, Asians and Caucasians had similar porosity and trabecular density. Results were similar using an adjusted fixed ROI. Adjusting for secular effects of age on forearm length resulted in the age-related increment in porosity increasing from 2.08 SD to 2.48 SD (p<0.05). Assessment of sex, race and age related differences in microstructure requires measurement of anatomically equivalent regions. Copyright © 2017 Elsevier

Heterogeneity in Kv7 channel function in the Cerebral and Coronary Circulation

PubMed Central

Tanner, Miles A.; Li, Min; Hill, Michael A.

2014-01-01

Kv7 channels are considered important regulators of vascular smooth muscle contractility. The present study examined the hypotheses that 1. Kv7 channels are present in mouse cerebral and coronary arteries and regulate vascular reactivity, and 2. regional differences exist in the activity of these channels. PCR confirmed that basilar, Circle of Willis and left anterior descending (LAD) arteries express predominantly Kv7.1 and 7.4. Western blot analysis, however, showed greater Kv7.4 protein levels in the cerebral vessels. Relaxation to the Kv7 channel activator, retigabine (1-50μM) was significantly greater in basilar compared to LAD. Similarly, the Kv7 channel inhibitor, linopirdine (10μM) caused stronger contraction of the basilar artery. Furthermore, pre-incubation with linopirdine reduced forskolin (cAMP activator)-induced vasorelaxation in basilar while not altering forskolin-induced vasorelaxation of the LAD, suggesting that Kv7 channels play a more prominent role in the cerebral than coronary circulation. Consistent with the vessel data, whole cell Kv7 currents in cerebral VSMCs were potentiated by retigabine and inhibited by linopirdine, while these responses were blunted in coronary VSMCs. This study provides evidence that mouse Kv7 channels may contribute differently to regulating the functional properties of cerebral and coronary arteries. Such heterogeneity has important implications for developing novel therapeutics for cardiovascular dysfunction. PMID:25476662

Cerebral hemodynamics and metabolism in patients with symptomatic occlusion of the internal carotid artery.

PubMed

Rutgers, D R; van Osch, M J P; Kappelle, L J; Mali, W P T M; van der Grond, J

2003-03-01

The goals of this study were to investigate (1) whether the concentrations of choline, creatine, and N-acetyl aspartate (NAA) in cerebral white matter are changed in patients with symptomatic occlusion of the internal carotid artery (ICA) and (2) whether possible changes in metabolite concentration are related to regional cerebral perfusion or cerebral vasoreactivity. In 19 patients (mean+/-SD age, 60+/-9 years), white matter metabolite concentrations were measured with proton MR spectroscopic imaging on average 4+/-2 months after symptoms occurred. In selected voxels, corresponding cerebral blood flow and volume, mean transit time, and time-to-bolus peak were determined with dynamic susceptibility contrast MRI. Cerebral CO2 reactivity was determined with transcranial Doppler sonography. No significant changes in choline and creatine concentrations were observed. NAA concentration was significantly reduced in the hemisphere on the side of the symptomatic ICA (9.1+/-1.7 mmol/L) compared with the contralateral hemisphere (10.5+/-1.7 mmol/L, P<0.005) and control subjects (10.5+/-0.9 mmol/L, P<0.01). Although no significant interhemispheric difference in NAA concentration was found in patients who presented with retinal ischemia, patients with cerebral ischemia had a significantly lower NAA concentration in the symptomatic hemisphere (9.0+/-1.7 mmol/L) compared with the asymptomatic hemisphere (10.4+/-1.6 mmol/L, P<0.05). In all patients, NAA concentration was not significantly correlated with quantitative cerebral perfusion parameters or CO2 reactivity. Patients with symptomatic ICA occlusion may show chronic neuronal damage in cerebral white matter as evidenced by reduced NAA concentration. This seems to be related to previous symptomatology rather than to the cerebral hemodynamic status in a chronic stage.

Simple retrograde cerebral perfusion is as good as complex antegrade cerebral perfusion for hemiarch replacement.

PubMed

Tanaka, Akiko; Estrera, Anthony L

2018-01-01

Cerebral complication is a major concern after aortic arch surgery, which may lead to death. Thus, cerebral protection strategy plays the key role to obtain respectable results in aortic arch repair. Deep hypothermic circulatory arrest was introduced in 1970s to decrease the ischemic insults to the brain. However, safe duration of circulatory arrest time was limited to 30 minutes. The 1990s was the decade of evolution for cerebral protection, in which two adjuncts for deep hypothermic circulatory arrest were introduced: retrograde and antegrade cerebral perfusion (ACP) techniques. These two cerebral perfusion techniques significantly decreased incidence of postoperative neurological dysfunction and mortality after aortic arch surgery. Although there are no large prospective studies that demonstrate which perfusion technique provide better outcomes, multiple retrospective studies implicate that ACP may decrease cerebral complications compared to retrograde cerebral perfusion (RCP) when a long circulatory arrest time is required during aortic arch reconstructions. To date, many surgeons favor ACP over RCP during a complex aortic arch repair, such as total arch replacement and hybrid arch replacement. However, the question is whether the use of ACP is necessary during a short, limited circulatory arrest time, such as hemiarch replacement? There is a paucity of data that proves the advantages of a complex ACP over a simple RCP for a short circulatory arrest time. RCP with deep hypothermic circulatory arrest is the simple, efficient cerebral protection technique with minimal interference to the surgical field-and it potentially allows to flush atheromatous debris out from the arch vessels. Thus, it is the preferred adjunct to deep hypothermic circulatory arrest during hemiarch replacement in our institution.

Simple retrograde cerebral perfusion is as good as complex antegrade cerebral perfusion for hemiarch replacement

PubMed Central

Tanaka, Akiko

2018-01-01

Cerebral complication is a major concern after aortic arch surgery, which may lead to death. Thus, cerebral protection strategy plays the key role to obtain respectable results in aortic arch repair. Deep hypothermic circulatory arrest was introduced in 1970s to decrease the ischemic insults to the brain. However, safe duration of circulatory arrest time was limited to 30 minutes. The 1990s was the decade of evolution for cerebral protection, in which two adjuncts for deep hypothermic circulatory arrest were introduced: retrograde and antegrade cerebral perfusion (ACP) techniques. These two cerebral perfusion techniques significantly decreased incidence of postoperative neurological dysfunction and mortality after aortic arch surgery. Although there are no large prospective studies that demonstrate which perfusion technique provide better outcomes, multiple retrospective studies implicate that ACP may decrease cerebral complications compared to retrograde cerebral perfusion (RCP) when a long circulatory arrest time is required during aortic arch reconstructions. To date, many surgeons favor ACP over RCP during a complex aortic arch repair, such as total arch replacement and hybrid arch replacement. However, the question is whether the use of ACP is necessary during a short, limited circulatory arrest time, such as hemiarch replacement? There is a paucity of data that proves the advantages of a complex ACP over a simple RCP for a short circulatory arrest time. RCP with deep hypothermic circulatory arrest is the simple, efficient cerebral protection technique with minimal interference to the surgical field—and it potentially allows to flush atheromatous debris out from the arch vessels. Thus, it is the preferred adjunct to deep hypothermic circulatory arrest during hemiarch replacement in our institution. PMID:29682460

Quantification of regional cerebral blood flow and volume with dynamic susceptibility contrast-enhanced MR imaging.

PubMed

Rempp, K A; Brix, G; Wenz, F; Becker, C R; Gückel, F; Lorenz, W J

1994-12-01

Quantification of regional cerebral blood flow (rCBF) and volume (rCBV) with dynamic magnetic resonance (MR) imaging. After bolus administration of a paramagnetic contrast medium, rapid T2*-weighted gradient-echo images of two sections were acquired for the simultaneous creation of concentration-time curves in the brain-feeding arteries and in brain tissue. Absolute rCBF and rCBV values were determined for gray and white brain matter in 12 subjects with use of principles of the indicator dilution theory. The mean rCBF value in gray matter was 69.7 mL/min +/- 29.7 per 100 g tissue and in white matter, 33.6 mL/min +/- 11.5 per 100 g tissue; the average rCBV was 8.0 mL +/- 3.1 per 100 g tissue and 4.2 mL +/- 1.0 per 100 g tissue, respectively. An age-related decrease in rCBF and rCBV for gray and white matter was observed. Preliminary data demonstrate that the proposed technique allows the quantification of rCBF and rCBV. Although the results are in good agreement with data from positron emission tomography studies, further evaluation is needed to establish the validity of method.

Effects of head-up vs. supine CPR on cerebral oxygenation and cerebral metabolism - a prospective, randomized porcine study.

PubMed

Putzer, Gabriel; Braun, Patrick; Martini, Judith; Niederstätter, Ines; Abram, Julia; Lindner, Andrea Katharina; Neururer, Sabrina; Mulino, Miriam; Glodny, Bernhard; Helbok, Raimund; Mair, Peter

2018-05-01

Recent studies have shown that during cardiopulmonary resuscitation (CPR) head-up position (HUP) as compared to standard supine position (SUP) decreases intracranial pressure (ICP) and increases cerebral perfusion pressure (CPP). The impact of this manoeuvre on brain oxygenation and metabolism is not clear. We therefore investigated HUP as compared to SUP during basic life support (BLS) CPR for their effect on brain oxygenation and metabolism. Twenty pigs were anaesthetized and instrumented. After 8 min of cardiac arrest (CA) pigs were randomized to either HUP or SUP and resuscitated mechanically for 20 min. Mean arterial pressure (MAP), ICP, CPP, cerebral regional oxygen saturation (rSO 2 ) and brain tissue oxygen tension (P bt O 2 ) were measured at baseline, after CA and every 5 min during CPR. Cerebral venous oxygen saturation (S cv O 2 ) was measured at baseline, after CA and after 20 min of CPR. Cerebral microdialysis parameters, e.g. lactate/pyruvate ratio (L/P ratio) were taken at baseline and the end of the experiment. ICP was significantly lower in HUP compared to SUP animals after 5 min (18.0 ± 4.5 vs. 24.1 ± 5.2 mmHg; p = 0.033) and 20 min (12.0 ± 3.4 vs. 17.8 ± 4.3 mmHg; p = 0.023) of CPR. Accordingly, CPP was significantly higher in the HUP group after 5 min (11.2 ± 9.5 vs. 1.0 ± 9.2 mmHg; p = 0.045) and 20 min (3.4 ± 6.4 vs. -3.8 ± 2.8 mmHg; p = 0.023) of CPR. However, no difference was found in rSO 2 , P bt O 2 , S cv O 2 and L/P ratio between groups after 20 min of CPR. In this animal model of BLS CPR, HUP as compared to SUP did not improve cerebral oxygenation or metabolism. Copyright © 2018. Published by Elsevier B.V.

Carbon Dioxide Fluctuations Are Associated with Changes in Cerebral Oxygenation and Electrical Activity in Infants Born Preterm.

PubMed

Dix, Laura Marie Louise; Weeke, Lauren Carleen; de Vries, Linda Simone; Groenendaal, Floris; Baerts, Willem; van Bel, Frank; Lemmers, Petra Maria Anna

2017-08-01

To evaluate the effects of acute arterial carbon dioxide partial pressure changes on cerebral oxygenation and electrical activity in infants born preterm. This retrospective observational study included ventilated infants born preterm with acute fluctuations of continuous end-tidal CO 2 (etCO 2 ) as a surrogate marker for arterial carbon dioxide partial pressure, during the first 72 hours of life. Regional cerebral oxygen saturation and fractional tissue oxygen extraction were monitored with near-infrared spectroscopy. Brain activity was monitored with 2-channel electroencephalography. Spontaneous activity transients (SATs) rate (SATs/minute) and interval between SATs (in seconds) were calculated. Ten-minute periods were selected for analysis: before, during, and after etCO 2 fluctuations of ≥5  mm Hg. Thirty-eight patients (mean ± SD gestational age of 29 ± 1.8 weeks) were included, with 60 episodes of etCO 2 increase and 70 episodes of etCO 2 decrease. During etCO 2 increases, brain oxygenation increased (regional cerebral oxygen saturation increased, fractional tissue oxygen extraction decreased; P < .01) and electrical activity decreased (SATs/minute decreased, interval between SATs increased; P < .01). All measures recovered when etCO 2 returned to baseline. During etCO 2 decreases, brain oxygenation decreased (regional cerebral oxygen saturation decreased, fractional tissue oxygen extraction decreased; P < .01) and brain activity increased (SATs/minute increased, P < .05), also with recovery after return of etCO 2 to baseline. An acute increase in etCO 2 is associated with increased cerebral oxygenation and decreased brain activity, whereas an acute decrease is associated with decreased cerebral oxygenation and slightly increased brain activity. Combining continuous CO 2 monitoring with near-infrared spectroscopy may enable the detection of otherwise undetected fluctuations in arterial carbon dioxide partial pressure that may be

Caffeine induced changes in cerebral circulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mathew, R.J.; Wilson, W.H.

1985-09-01

While the caffeine induced cerebral vasoconstriction is well documented, the effects of oral ingestion of the drug in a dose range comparable to the quantities in which it is usually consumed and the intensity and duration of the associated reduction in cerebral circulation are unknown. Cerebral blood flow was measured via the TTXenon inhalation technique before and thirty and ninety minutes after the oral administration of 250 mg of caffeine or a placebo, under double-blind conditions. Caffeine ingestion was found to be associated with significant reductions in cerebral perfusion thirty and ninety minutes later. The placebo group showed no differencesmore » between the three sets of cerebral blood flow values.« less

Implementing automatic LiDAR and supervised mapping methodologies to quantify agricultural terraced landforms at landscape scale: the case of Veneto Region

NASA Astrophysics Data System (ADS)

Eugenio Pappalardo, Salvatore; Ferrarese, Francesco; Tarolli, Paolo; Varotto, Mauro

2016-04-01

Traditional agricultural terraced landscapes presently embody an important cultural value to be deeply investigated, both for their role in local heritage and cultural economy and for their potential geo-hydrological hazard due to abandonment and degradation. Moreover, traditional terraced landscapes are usually based on non-intensive agro-systems and may enhance some important ecosystems services such as agro-biodiversity conservation and cultural services. Due to their unplanned genesis, mapping, quantifying and classifying agricultural terraces at regional scale is often critical as far as they are usually set up on geomorphologically and historically complex landscapes. Hence, traditional mapping methods are generally based on scientific literature and local documentation, historical and cadastral sources, technical cartography and aerial images visual interpretation or, finally, field surveys. By this, limitations and uncertainty in mapping at regional scale are basically related to forest cover and lack in thematic cartography. The Veneto Region (NE of Italy) presents a wide heterogeneity of agricultural terraced landscapes, mainly distributed within the hilly and Prealps areas. Previous studies performed by traditional mapping method quantified 2,688 ha of terraced areas, showing the higher values within the Prealps of Lessinia (1,013 ha, within the Province of Verona) and in the Brenta Valley (421 ha, within the Province of Vicenza); however, terraced features of these case studies show relevant differences in terms of fragmentation and intensity of terraces, highlighting dissimilar degrees of clusterization: 1.7 ha on one hand (Province of Verona) and 1.2 ha per terraced area (Province of Vicenza) on the other one. The aim of this paper is to implement and to compare automatic methodologies with traditional survey methodologies to map and assess agricultural terraces in two representative areas of the Veneto Region. Testing different Remote Sensing

Cerebral metabolic dysfunction and impaired vigilance in recently abstinent methamphetamine abusers.

PubMed

London, Edythe D; Berman, Steven M; Voytek, Bradley; Simon, Sara L; Mandelkern, Mark A; Monterosso, John; Thompson, Paul M; Brody, Arthur L; Geaga, Jennifer A; Hong, Michael S; Hayashi, Kiralee M; Rawson, Richard A; Ling, Walter

2005-11-15

Methamphetamine (MA) abusers have cognitive deficits, abnormal metabolic activity and structural deficits in limbic and paralimbic cortices, and reduced hippocampal volume. The links between cognitive impairment and these cerebral abnormalities are not established. We assessed cerebral glucose metabolism with [F-18]fluorodeoxyglucose positron emission tomography in 17 abstinent (4 to 7 days) methamphetamine users and 16 control subjects performing an auditory vigilance task and obtained structural magnetic resonance brain scans. Regional brain radioactivity served as a marker for relative glucose metabolism. Error rates on the task were related to regional radioactivity and hippocampal morphology. Methamphetamine users had higher error rates than control subjects on the vigilance task. The groups showed different relationships between error rates and relative activity in the anterior and middle cingulate gyrus and the insula. Whereas the MA user group showed negative correlations involving these regions, the control group showed positive correlations involving the cingulate cortex. Across groups, hippocampal metabolic and structural measures were negatively correlated with error rates. Dysfunction in the cingulate and insular cortices of recently abstinent MA abusers contribute to impaired vigilance and other cognitive functions requiring sustained attention. Hippocampal integrity predicts task performance in methamphetamine users as well as control subjects.

What makes children with cerebral palsy vulnerable to malnutrition? Findings from the Bangladesh cerebral palsy register (BCPR).

PubMed

Jahan, Israt; Muhit, Mohammad; Karim, Tasneem; Smithers-Sheedy, Hayley; Novak, Iona; Jones, Cheryl; Badawi, Nadia; Khandaker, Gulam

2018-04-16

To assess the nutritional status and underlying risk factors for malnutrition among children with cerebral palsy in rural Bangladesh. We used data from the Bangladesh Cerebral Palsy Register; a prospective population based surveillance of children with cerebral palsy aged 0-18 years in a rural subdistrict of Bangladesh (i.e., Shahjadpur). Socio-demographic, clinical and anthropometric measurements were collected using Bangladesh Cerebral Palsy Register record form. Z scores were calculated using World Health Organization Anthro and World Health Organization AnthroPlus software. A total of 726 children with cerebral palsy were registered into the Bangladesh Cerebral Palsy Register (mean age 7.6 years, standard deviation 4.5, 38.1% female) between January 2015 and December 2016. More than two-third of children were underweight (70.0%) and stunted (73.1%). Mean z score for weight for age, height for age and weight for height were -2.8 (standard deviation 1.8), -3.1 (standard deviation 2.2) and -1.2 (standard deviation 2.3) respectively. Moderate to severe undernutrition (i.e., both underweight and stunting) were significantly associated with age, monthly family income, gross motor functional classification system and neurological type of cerebral palsy. The burden of undernutrition is high among children with cerebral palsy in rural Bangladesh which is augmented by both poverty and clinical severity. Enhancing clinical nutritional services for children with cerebral palsy should be a public health priority in Bangladesh. Implications for Rehabilitation Population-based surveillance data on nutritional status of children with cerebral palsy in Bangladesh indicates substantially high burden of malnutrition among children with CP in rural Bangladesh. Children with severe form of cerebral palsy, for example, higher Gross Motor Function Classification System (GMFCS) level, tri/quadriplegic cerebral palsy presents the highest proportion of severe malnutrition; hence, these

Cerebral Arterial Occlusion Did Not Promote the Prevalence of Cerebral Amyloid Angiopathy.

PubMed

Honda, Kazuhiro

2016-08-01

An impairment of amyloid-β (Aβ) clearance has been suggested in Alzheimer's disease. Perivascular drainage along cerebrovascular vessels is considered an important amyloid clearance pathway. This study examined the effect of reduced arterial pulsation that could cause an impairment in cerebral amyloid drainage on the prevalence of cortical microbleeds (CMBs), a surrogate marker for cerebral amyloid angiopathy (CAA). Patients who lost depiction of either side of the carotid artery or the middle cerebral artery on magnetic resonance angiography were studied. Those who showed acute cerebral infarction or a previous cortical cerebral infarction were excluded. The number of CMBs was counted on the occluded and non-occluded sides of the brain in each subject. The number of subjects who showed more CMBs on the occluded side of the brain was compared with the number of subjects who showed more CMBs on the non-occluded side of the brain. Twenty-eight patients were studied. The extent of lacunar infarction and white matter lesions was not different, irrespective of the occluded vessels or the distribution of CMBs. The prevalence of CMBs was not different between the occluded and non-occluded sides of the brain. In this cross-sectional study, reduction of arterial pulsation was not associated with a higher prevalence of CAA. Therefore, reduced arterial pulsation alone may not be enough to promote CAA.

Prefrontal cerebral blood volume patterns while playing video games--a near-infrared spectroscopy study.

PubMed

Nagamitsu, Shinichiro; Nagano, Miki; Yamashita, Yushiro; Takashima, Sachio; Matsuishi, Toyojiro

2006-06-01

Video game playing is an attractive form of entertainment among school-age children. Although this activity reportedly has many adverse effects on child development, these effects remain controversial. To investigate the effect of video game playing on regional cerebral blood volume, we measured cerebral hemoglobin concentrations using near-infrared spectroscopy in 12 normal volunteers consisting of six children and six adults. A Hitachi Optical Topography system was used to measure hemoglobin changes. For all subjects, the video game Donkey Kong was played on a Game Boy device. After spectroscopic probes were positioned on the scalp near the target brain regions, the participants were asked to play the game for nine periods of 15s each, with 15-s rest intervals between these task periods. Significant increases in bilateral prefrontal total-hemoglobin concentrations were observed in four of the adults during video game playing. On the other hand, significant decreases in bilateral prefrontal total-hemoglobin concentrations were seen in two of the children. A significant positive correlation between mean oxy-hemoglobin changes in the prefrontal region and those in the bilateral motor cortex area was seen in adults. Playing video games gave rise to dynamic changes in cerebral blood volume in both age groups, while the difference in the prefrontal oxygenation patterns suggested an age-dependent utilization of different neural circuits during video game tasks.

Cerebral serotonin transporter binding is inversely related to body mass index.

PubMed

Erritzoe, D; Frokjaer, V G; Haahr, M T; Kalbitzer, J; Svarer, C; Holst, K K; Hansen, D L; Jernigan, T L; Lehel, S; Knudsen, G M

2010-08-01

Overweight and obesity is a health threat of increasing concern and understanding the neurobiology behind obesity is instrumental to the development of effective treatment regimes. Serotonergic neurotransmission is critically involved in eating behaviour; cerebral level of serotonin (5-HT) in animal models is inversely related to food intake and body weight and some effective anti-obesity agents involve blockade of the serotonin transporter (SERT). We investigated in 60 healthy volunteers body mass index (BMI) and regional cerebral SERT binding as measured with [(11)C]DASB PET. In a linear regression model with adjustment for relevant covariates, we found that cortical and subcortical SERT binding was negatively correlated to BMI (-0.003 to -0.012 BP(ND) unit per kg/m(2)). Tobacco smoking and alcohol consumption did not affect cerebral SERT binding. Several effective anti-obesity drugs encompass blockade of the SERT; yet, our study is the first to demonstrate an abnormally decreased cerebral SERT binding in obese individuals. Whether the SERT has a direct role in the regulation of appetite and eating behaviour or whether the finding is due to a compensatory downregulation of SERT secondary to other dysfunction(s) in the serotonergic transmitter system, such as low baseline serotonin levels, remains to be established. Copyright 2010 Elsevier Inc. All rights reserved.

Ferulic acid prevents cerebral ischemic injury-induced reduction of hippocalcin expression.

PubMed

Koh, Phil-Ok

2013-07-01

Intracellular calcium overload is a critical pathophysiological factor in ischemic injury. Hippocalcin is a neuronal calcium sensor protein that buffers intracellular calcium levels and protects cells from apoptotic stimuli. Ferulic acid exerts a neuroprotective effect in cerebral ischemia through its anti-oxidant and anti-inflammation activity. This study investigated whether ferulic acid contributes to hippocalcin expression during cerebral ischemia and glutamate exposure-induced neuronal cell death. Rats were immediately treated with vehicle or ferulic acid (100 mg/kg, i.v.) after middle cerebral artery occlusion (MCAO). Brain tissues were collected 24 h after MCAO and followed by assessment of cerebral infarct. Ferulic acid reduced MCAO-induced infarct regions. A proteomics approach elucidated a decrease in hippocalcin in MCAO-operated animals, ferulic acid attenuates the injury-induced decrease in hippocalcin expression. Reverse transcription-polymerase chain reaction and Western blot analyses confirmed that ferulic acid prevents the injury-induced decrease in hippocalcin. In cultured HT22 hippocampal cells, glutamate exposure increased the intracellular Ca(2+) levels, whereas ferulic acid attenuated this increase. Moreover, ferulic acid attenuated the glutamate toxicity-induced decrease in hippocalcin expression. These findings can suggest the possibility that ferulic acid exerts a neuroprotective effect through modulating hippocalcine expression and regulating intracellular calcium levels. Copyright © 2013 Wiley Periodicals, Inc.

Post traumatic brain perfusion SPECT analysis using reconstructed ROI maps of radioactive microsphere derived cerebral blood flow and statistical parametric mapping

PubMed Central

McGoron, Anthony J; Capille, Michael; Georgiou, Michael F; Sanchez, Pablo; Solano, Juan; Gonzalez-Brito, Manuel; Kuluz, John W

2008-01-01

Background Assessment of cerebral blood flow (CBF) by SPECT could be important in the management of patients with severe traumatic brain injury (TBI) because changes in regional CBF can affect outcome by promoting edema formation and intracranial pressure elevation (with cerebral hyperemia), or by causing secondary ischemic injury including post-traumatic stroke. The purpose of this study was to establish an improved method for evaluating regional CBF changes after TBI in piglets. Methods The focal effects of moderate traumatic brain injury (TBI) on cerebral blood flow (CBF) by SPECT cerebral blood perfusion (CBP) imaging in an animal model were investigated by parallelized statistical techniques. Regional CBF was measured by radioactive microspheres and by SPECT 2 hours after injury in sham-operated piglets versus those receiving severe TBI by fluid-percussion injury to the left parietal lobe. Qualitative SPECT CBP accuracy was assessed against reference radioactive microsphere regional CBF measurements by map reconstruction, registration and smoothing. Cerebral hypoperfusion in the test group was identified at the voxel level using statistical parametric mapping (SPM). Results A significant area of hypoperfusion (P < 0.01) was found as a response to the TBI. Statistical mapping of the reference microsphere CBF data confirms a focal decrease found with SPECT and SPM. Conclusion The suitability of SPM for application to the experimental model and ability to provide insight into CBF changes in response to traumatic injury was validated by the SPECT SPM result of a decrease in CBP at the left parietal region injury area of the test group. Further study and correlation of this characteristic lesion with long-term outcomes and auxiliary diagnostic modalities is critical to developing more effective critical care treatment guidelines and automated medical imaging processing techniques. PMID:18312639

Post traumatic brain perfusion SPECT analysis using reconstructed ROI maps of radioactive microsphere derived cerebral blood flow and statistical parametric mapping.

PubMed

McGoron, Anthony J; Capille, Michael; Georgiou, Michael F; Sanchez, Pablo; Solano, Juan; Gonzalez-Brito, Manuel; Kuluz, John W

2008-02-29

Assessment of cerebral blood flow (CBF) by SPECT could be important in the management of patients with severe traumatic brain injury (TBI) because changes in regional CBF can affect outcome by promoting edema formation and intracranial pressure elevation (with cerebral hyperemia), or by causing secondary ischemic injury including post-traumatic stroke. The purpose of this study was to establish an improved method for evaluating regional CBF changes after TBI in piglets. The focal effects of moderate traumatic brain injury (TBI) on cerebral blood flow (CBF) by SPECT cerebral blood perfusion (CBP) imaging in an animal model were investigated by parallelized statistical techniques. Regional CBF was measured by radioactive microspheres and by SPECT 2 hours after injury in sham-operated piglets versus those receiving severe TBI by fluid-percussion injury to the left parietal lobe. Qualitative SPECT CBP accuracy was assessed against reference radioactive microsphere regional CBF measurements by map reconstruction, registration and smoothing. Cerebral hypoperfusion in the test group was identified at the voxel level using statistical parametric mapping (SPM). A significant area of hypoperfusion (P < 0.01) was found as a response to the TBI. Statistical mapping of the reference microsphere CBF data confirms a focal decrease found with SPECT and SPM. The suitability of SPM for application to the experimental model and ability to provide insight into CBF changes in response to traumatic injury was validated by the SPECT SPM result of a decrease in CBP at the left parietal region injury area of the test group. Further study and correlation of this characteristic lesion with long-term outcomes and auxiliary diagnostic modalities is critical to developing more effective critical care treatment guidelines and automated medical imaging processing techniques.

[Advances in genetic research of cerebral palsy].

PubMed

Wang, Fang-Fang; Luo, Rong; Qu, Yi; Mu, De-Zhi

2017-09-01

Cerebral palsy is a group of syndromes caused by non-progressive brain injury in the fetus or infant and can cause disabilities in childhood. Etiology of cerebral palsy has always been a hot topic for clinical scientists. More and more studies have shown that genetic factors are closely associated with the development of cerebral palsy. With the development and application of various molecular and biological techniques such as chromosome microarray analysis, genome-wide association study, and whole exome sequencing, new achievements have been made in the genetic research of cerebral palsy. Chromosome abnormalities, copy number variations, susceptibility genes, and single gene mutation associated with the development of cerebral palsy have been identified, which provides new opportunities for the research on the pathogenesis of cerebral palsy. This article reviews the advances in the genetic research on cerebral palsy in recent years.

Changes in Cerebral Cortex of Children Treated for Medulloblastoma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Arthur K.; Marcus, Karen J.; Department of Radiation Oncology, Dana Farber Cancer Institute, Harvard Medical School, Boston, MA

2007-07-15

Purpose: Children with medulloblastoma undergo surgery, radiotherapy, and chemotherapy. After treatment, these children have numerous structural abnormalities. Using high-resolution magnetic resonance imaging, we measured the thickness of the cerebral cortex in a group of medulloblastoma patients and a group of normally developing children. Methods and Materials: We obtained magnetic resonance imaging scans and measured the cortical thickness in 9 children after treatment of medulloblastoma. The measurements from these children were compared with the measurements from age- and gender-matched normally developing children previously scanned. For additional comparison, the pattern of thickness change was compared with the cortical thickness maps from amore » larger group of 65 normally developing children. Results: In the left hemisphere, relatively thinner cortex was found in the perirolandic region and the parieto-occipital lobe. In the right hemisphere, relatively thinner cortex was found in the parietal lobe, posterior superior temporal gyrus, and lateral temporal lobe. These regions of cortical thinning overlapped with the regions of cortex that undergo normal age-related thinning. Conclusion: The spatial distribution of cortical thinning suggested that the areas of cortex that are undergoing development are more sensitive to the effects of treatment of medulloblastoma. Such quantitative methods may improve our understanding of the biologic effects that treatment has on the cerebral development and their neuropsychological implications.« less

Direct visualization of minimal cerebral capillary flow during retrograde cerebral perfusion: an intravital fluorescence microscopy study in pigs.

PubMed

Duebener, Lennart F; Hagino, Ikuo; Schmitt, Katharina; Sakamoto, Takahiko; Stamm, Christof; Zurakowski, David; Schäfers, Hans-Joachim; Jonas, Richard A

2003-04-01

Retrograde cerebral perfusion (RCP) is used in some centers during aortic arch surgery for brain protection during hypothermic circulatory arrest. It is still unclear however whether RCP provides adequate microcirculatory blood flow at a capillary level. We used intravital microscopy to directly visualize the cerebral capillary blood flow in a piglet model of RCP. Twelve pigs (weight 9.7 +/- 0.9 kg) were divided into two groups (n = 6 each): deep hypothermic circulatory arrest (DHCA) and RCP. After the creation of a window over the parietal cerebral cortex, pigs underwent 10 minutes of normothermic bypass and 40 minutes of cooling to 15 degrees C on cardiopulmonary bypass ([CPB] pH-stat, hemocrit 30%, pump flow 100 mL x kg(-1) x min(-1)). This was followed by 45 minutes of DHCA and rewarming on CPB to 37 degrees C. In the RCP group the brain was retrogradely perfused (pump flow 30 mL x kg(-1) x min(-1)) during DHCA through the superior vena cava after inferior vena cava occlusion. Plasma was labeled with fluorescein-isothiocyanate-dextran for assessing microvascular diameter and functional capillary density (FCD), defined as total length of erythrocyte-perfused capillaries per observation area. Cerebral tissue oxygenation was determined by nicotinamide adenine dinucleotide hydrogen (NADH) autofluorescence, which increases during tissue ischemia. During normothermic and hypothermic antegrade cerebral perfusion the FCD did not significantly change from base line (97% +/- 14% and 96% +/- 12%, respectively). During retrograde cerebral perfusion the FCD decreased highly significantly to 2% +/- 2% of base line values (p < 0.001). Thus there was no evidence of significant capillary blood flow during retrograde cerebral perfusion. The microvascular diameter of cerebral arterioles that were slowly perfused significantly decreased to 27% +/- 6% of base line levels during RCP. NADH fluorescence progressively and significantly increased during RCP, indicating poorer tissue

Cerebral microbleeds: different prevalence, topography, and risk factors depending on dementia diagnosis—the Karolinska Imaging Dementia Study.

PubMed

Shams, S; Martola, J; Granberg, T; Li, X; Shams, M; Fereshtehnejad, S M; Cavallin, L; Aspelin, P; Kristoffersen-Wiberg, M; Wahlund, L O

2015-04-01

Cerebral microbleeds are thought to represent cerebral amyloid angiopathy when in lobar regions of the brain and hypertensive arteriopathy when in deep and infratentorial locations. By studying cerebral microbleeds, their topography, and risk factors, we aimed to gain an insight into the vascular and amyloid pathology of dementia diagnoses and increase the understanding of cerebral microbleeds in dementia. We analyzed 1504 patients (53% women; mean age, 63 ± 10 years; 10 different dementia diagnoses) in this study. All patients underwent MR imaging as part of the dementia investigation, and all their clinical parameters were recorded. Among the 1504 patients with dementia, 22% had cerebral microbleeds. Cerebral microbleed topography was predominantly lobar (P = .01) and occipital (P = .007) in Alzheimer disease. Patients with cerebral microbleeds were significantly older (P < .001), were more frequently male (P < .001), had lower cognitive scores (P = .006), and more often had hypertension (P < .001). Risk factors for cerebral microbleeds varied depending on the dementia diagnosis. Odds ratios for having cerebral microbleeds increased with the number of risk factors (hypertension, hyperlipidemia, diabetes, male sex, and age 65 and older) in the whole patient group and increased differently in the separate dementia diagnoses. Prevalence, topography, and risk factors of cerebral microbleeds vary depending on the dementia diagnosis and reflect the inherent pathology of different dementia diagnoses. Because cerebral microbleeds are seen as possible predictors of intracerebral hemorrhage, their increasing prevalence with an increasing number of risk factors, as shown in our study, may require taking the number of risk factors into account when deciding on anticoagulant therapy in dementia. © 2015 by American Journal of Neuroradiology.

Gastrocnemius operating length with ankle foot orthoses in cerebral palsy.

PubMed

Choi, Hwan; Wren, Tishya Anne Leong; Steele, Katherine Muterspaugh

2017-06-01

Many individuals with cerebral palsy wear ankle foot orthoses during daily life. Orthoses influence joint motion, but how they impact muscle remains unclear. In particular, the gastrocnemius is commonly stiff in cerebral palsy. Understanding whether orthoses stretch or shorten this muscle during daily life may inform orthosis design and rehabilitation. This study investigated the impact of different ankle foot orthoses on gastrocnemius operating length during walking in children with cerebral palsy. Case series, within subject comparison of gastrocnemius operating length while walking barefoot and with two types of ankle foot orthoses. We performed gait analyses for 11 children with cerebral palsy. Each child was fit with two types of orthoses: a dynamic ankle foot orthosis (Cascade dynamic ankle foot orthosis) and an adjustable dynamic response ankle foot orthosis (Ultraflex ankle foot orthosis). Musculoskeletal modeling was used to quantify gastrocnemius musculotendon operating length and velocity with each orthosis. Walking with ankle foot orthoses could stretch the gastrocnemius more than barefoot walking for some individuals; however, there was significant variability between participants and orthoses. At least one type of orthosis stretched the gastrocnemius during walking for 4/6 and 3/5 of the Gross Motor Functional Classification System Level I and III participants, respectively. AFOs also reduced peak gastrocnemius lengthening velocity compared to barefoot walking for some participants, with greater reductions among the Gross Motor Functional Classification System Level III participants. Changes in gastrocnemius operating length and lengthening velocity were related to changes in ankle and knee kinematics during gait. Ankle foot orthoses impact gastrocnemius operating length during walking and, with proper design, may assist with stretching tight muscles in daily life. Clinical relevance Determining whether ankle foot orthoses stretch tight muscles can

Cerebral Lateralization and Aggression.

ERIC Educational Resources Information Center

Hillbrand, Marc; And Others

1994-01-01

A resurgence of interest in the relationship between cerebral lateralization (the functional asymmetry of the cerebral cortex) and aggression has occurred. Most recent studies have found that individuals with abnormal patterns of lateralization are overrepresented among violent individuals. Intervening variables (such as drug and alcohol abuse)…

Neurodevelopmental outcomes after regional cerebral perfusion with neuromonitoring for neonatal aortic arch reconstruction.

PubMed

Andropoulos, Dean B; Easley, R Blaine; Brady, Ken; McKenzie, E Dean; Heinle, Jeffrey S; Dickerson, Heather A; Shekerdemian, Lara S; Meador, Marcie; Eisenman, Carol; Hunter, Jill V; Turcich, Marie; Voigt, Robert G; Fraser, Charles D

2013-02-01

In this study we report magnetic resonance imaging (MRI) brain injury and 12-month neurodevelopmental outcomes when regional cerebral perfusion (RCP) is used for neonatal aortic arch reconstruction. Fifty-seven neonates receiving RCP during aortic arch reconstruction were enrolled in a prospective outcome study. RCP flows were determined by near-infrared spectroscopy and transcranial Doppler monitoring. Brain MRI was performed preoperatively and 7 days postoperatively. Bayley Scales of Infant Development III was performed at 12 months. Mean RCP time was 71 ± 28 minutes (range, 5 to 121 minutes) and mean flow was 56.6 ± 10.6 mL/kg/min. New postoperative MRI brain injury was seen in 40% of patients. For 35 RCP patients at age 12 months, mean Bayley Scales III Composite standard scores were: Cognitive, 100.1 ± 14.6 (range, 75 to 125); Language, 87.2 ± 15.0 (range, 62 to 132); and Motor, 87.9 ± 16.8 (range, 58 to 121). Increasing duration of RCP was not associated with adverse neurodevelopmental outcomes. Neonatal aortic arch repair with RCP using a neuromonitoring strategy results in 12-month cognitive outcomes that are at reference population norms. Language and motor outcomes are lower than the reference population norms by 0.8 to 0.9 standard deviations. The neurodevelopmental outcomes in this RCP cohort demonstrate that this technique is effective and safe in supporting the brain during neonatal aortic arch reconstruction. Copyright © 2013 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Abnormal regional cerebral blood flow in systemic lupus erythematosus patients with psychiatric symptoms.

PubMed

Oda, Kenji; Matsushima, Eisuke; Okubo, Yoshiro; Ohta, Katsuya; Murata, Yuji; Koike, Ryuji; Miyasaka, Nobuyuki; Kato, Motoichiro

2005-07-01

Single-photon emission computed tomography (SPECT) studies have demonstrated decreased regional cerebral blood flow (rCBF) in systemic lupus erythematosus (SLE) patients. However, no study has done voxel-based analysis using statistical parametric mapping (SPM) that can evaluate rCBF objectively, and the relationship between rCBF and psychiatric symptoms has not been well investigated. Using L,L-ethyl cysteinate dimer (99mTc ECD) SPECT and SPM, we aimed to clarify the association of rCBF changes with psychiatric symptoms in SLE patients whose magnetic resonance imaging (MRI) showed no morphological abnormalities. Twenty SLE patients and 19 healthy volunteers underwent 99mTc ECD SPECT. Data were collected from August 2000 to March 2003. SLE was diagnosed according to American College of Rheumatology criteria, and psychiatric symptoms were diagnosed according to ICD-10 criteria. On the basis of the modified Carbotte, Denburg, and Denburg method, the patients were classified into 3 groups: a group with major psychiatric symptoms (hallucinosis, delusional disorder, and mood disorder), a group with minor psychiatric symptoms (anxiety disorder, dissociative disorder, and emotionally labile disorder), and a group without psychiatric symptoms. Gross organic lesions were ruled out by brain MRI. Group comparisons of rCBF were performed with analysis using SPM99. SLE patients without MRI lesions showed decreased rCBF in the posterior cingulate gyrus and thalamus. The reduction in rCBF was overt in patients with major psychiatric symptoms. Our study indicated that SLE patients may have dysfunction in the posterior cingulate gyrus and thalamus and that this may be associated with the severity of psychiatric symptoms.

Laying the foundation for quantifying regional exposure to social phenomena: considering the case of legalized gambling as a public health toxin.

PubMed

Shaffer, Howard J; LaBrie, Richard A; LaPlante, Debi

2004-03-01

Exposure and adaptation models provide competing perspectives of the environmental influence on the development of addictive disorders. Exposure theory suggests that the presence of environmental toxins (e.g., casinos) increases the likelihood of related disease (e.g., gambling-related disorders). Adaptation theory proposes that new environmental toxins initially increase adverse reactions; subsequently, symptoms diminish as individuals adapt to such toxins and acquire resistance. The authors describe a new public health regional exposure model (REM) that provides a tool to gather empirical evidence in support of either model. This article demonstrates how the strategic REM, modified to examine gambling exposure, uses standardized indices of exposure to social phenomena at the regional level to quantify social constructs.

Puerarin Attenuates Cerebral Damage by Improving Cerebral Microcirculation in Spontaneously Hypertensive Rats

PubMed Central

Wu, Xu-Dong; Wang, Chen; Zhang, Zhen-Ying; Fu, Yan; Liu, Feng-Ying; Liu, Xiu-Hua

2014-01-01

Puerariae Lobatae Radix (Gegen in Chinese) is the dried root of Pueraria lobata, a semiwoody, perennial, and leguminous vine native to China. Puerarin is one of the effective components of isoflavones isolated from the root of Pueraria lobata. Previous studies showed that extracts derived from the root of Pueraria lobata possessed antihypertensive effect. Our study is to investigate whether puerarin contributes to prevention of stroke by improving cerebral microcirculation in rats. Materials and Methods. Video microscopy and laser Doppler perfusion imaging on the pia mater were used to measure the diameter of microvessel and blood perfusion in 12-week old spontaneously hypertensive rats (SHRs) and age-matched normotensive WKY rats. Histological alterations were observed by hematoxylin and eosin staining, and microvessel density in cerebral tissue was measured by immunohistochemical analysis with anti-Factor VIII antibody. Cell proliferation was detected by [3H]-TdR incorporation, and activities of p42/44 mitogen activated protein kinases (p42/44 MAPKs) were detected by western blot analysis in cultured cerebral microvascular endothelial cells (MECs). Results. Intravenous injection of puerarin relaxed arterioles and increased the blood flow perfusion in the pia mater in SHRs. Puerarin treatment for 14 days reduced the blood pressure to a normal level in SHRs (P < 0.05) and increased the arteriole diameter in the pia mater significantly as compared with vehicle treatment. Arteriole remodeling, edema, and ischemia in cerebral tissue were attenuated in puerarin-treated SHRs. Microvessel density in cerebral tissue was greater with puerarin than with vehicle treatment. Puerarin-treated MECs showed greater proliferation and p42/44 MAPKs activities than vehicle treatment. Conclusions. Puerarin possesses effects of antihypertension and stroke prevention by improved microcirculation in SHRs, which results from the increase in cerebral blood perfusion both by arteriole

In vitro strain measurements in cerebral aneurysm models for cyber-physical diagnosis.

PubMed

Shi, Chaoyang; Kojima, Masahiro; Anzai, Hitomi; Tercero, Carlos; Ikeda, Seiichi; Ohta, Makoto; Fukuda, Toshio; Arai, Fumihito; Najdovski, Zoran; Negoro, Makoto; Irie, Keiko

2013-06-01

The development of new diagnostic technologies for cerebrovascular diseases requires an understanding of the mechanism behind the growth and rupture of cerebral aneurysms. To provide a comprehensive diagnosis and prognosis of this disease, it is desirable to evaluate wall shear stress, pressure, deformation and strain in the aneurysm region, based on information provided by medical imaging technologies. In this research, we propose a new cyber-physical system composed of in vitro dynamic strain experimental measurements and computational fluid dynamics (CFD) simulation for the diagnosis of cerebral aneurysms. A CFD simulation and a scaled-up membranous silicone model of a cerebral aneurysm were completed, based on patient-specific data recorded in August 2008. In vitro blood flow simulation was realized with the use of a specialized pump. A vision system was also developed to measure the strain at different regions on the model by way of pulsating blood flow circulating inside the model. Experimental results show that distance and area strain maxima were larger near the aneurysm neck (0.042 and 0.052), followed by the aneurysm dome (0.023 and 0.04) and finally the main blood vessel section (0.01 and 0.014). These results were complemented by a CFD simulation for the addition of wall shear stress, oscillatory shear index and aneurysm formation index. Diagnosis results using imaging obtained in August 2008 are consistent with the monitored aneurysm growth in 2011. The presented study demonstrates a new experimental platform for measuring dynamic strain within cerebral aneurysms. This platform is also complemented by a CFD simulation for advanced diagnosis and prediction of the growth tendency of an aneurysm in endovascular surgery. Copyright © 2013 John Wiley & Sons, Ltd.

Quantifying the uncertainty of regional and national estimates of soil carbon stocks

NASA Astrophysics Data System (ADS)

Papritz, Andreas

2013-04-01

At regional and national scales, carbon (C) stocks are frequently estimated by means of regression models. Such statistical models link measurements of carbons stocks, recorded for a set of soil profiles or soil cores, to covariates that characterize soil formation conditions and land management. A prerequisite is that these covariates are available for any location within a region of interest G because they are used along with the fitted regression coefficients to predict the carbon stocks at the nodes of a fine-meshed grid that is laid over G. The mean C stock in G is then estimated by the arithmetic mean of the stock predictions for the grid nodes. Apart from the mean stock, the precision of the estimate is often also of interest, for example to judge whether the mean C stock has changed significantly between two inventories. The standard error of the estimated mean stock in G can be computed from the regression results as well. Two issues are thereby important: (i) How large is the area of G relative to the support of the measurements? (ii) Are the residuals of the regression model spatially auto-correlated or is the assumption of statistical independence tenable? Both issues are correctly handled if one adopts a geostatistical block kriging approach for estimating the mean C stock within a region and its standard error. In the presentation I shall summarize the main ideas of external drift block kriging. To compute the standard error of the mean stock, one has in principle to sum the elements a potentially very large covariance matrix of point prediction errors, but I shall show that the required term can be approximated very well by Monte Carlo techniques. I shall further illustrated with a few examples how the standard error of the mean stock estimate changes with the size of G and with the strenght of the auto-correlation of the regression residuals. As an application a robust variant of block kriging is used to quantify the mean carbon stock stored in the

Comparing cerebral perfusion in Alzheimer's disease and Parkinson's disease dementia: an ASL-MRI study.

PubMed

Le Heron, Campbell J; Wright, Sarah L; Melzer, Tracy R; Myall, Daniel J; MacAskill, Michael R; Livingston, Leslie; Keenan, Ross J; Watts, Richard; Dalrymple-Alford, John C; Anderson, Tim J

2014-06-01

Emerging evidence suggests that Alzheimer's disease (AD) and Parkinson's disease dementia (PDD) share neurodegenerative mechanisms. We sought to directly compare cerebral perfusion in these two conditions using arterial spin labeling magnetic resonance imaging (ASL-MRI). In total, 17 AD, 20 PDD, and 37 matched healthy controls completed ASL and structural MRI, and comprehensive neuropsychological testing. Alzheimer's disease and PDD perfusion was analyzed by whole-brain voxel-based analysis (to assess absolute blood flow), a priori specified region of interest analysis, and principal component analysis (to generate a network differentiating the two groups). Corrections were made for cerebral atrophy, age, sex, education, and MRI scanner software version. Analysis of absolute blood flow showed no significant differences between AD and PDD. Comparing each group with controls revealed an overlapping, posterior pattern of hypoperfusion, including posterior cingulate gyrus, precuneus, and occipital regions. The perfusion network that differentiated AD and PDD groups identified relative differences in medial temporal lobes (ADcerebral hypoperfusion is very similar in AD and PDD. This suggests closely linked mechanisms of neurodegeneration mediating the evolution of dementia in both conditions.

Deep Hypothermic Circulatory Arrest vs. Antegrade Cerebral Perfusion in Cerebral Protection during the Surgical Treatment of Chronic Dissection of the Ascending and Arch Aorta

PubMed Central

Kamenskaya, Oksana Vasilyevna; Klinkova, Asya Stanislavovna; Chernyavsky, Alexander Mikhailovich; Lomivorotov, Vladimir Vladimirovich; Meshkov, Ivan Olegovich; Karaskov, Alexander Mikhailovich

2017-01-01

Abstract: Circulatory arrest during aortic surgery presents a risk of neurological complications. The present study aimed to investigate the effectiveness of deep hypothermic circulatory arrest (DHCA) vs. antegrade cerebral perfusion (ACP) in cerebral protection during the surgical treatment of chronic dissection of the ascending and arch aorta and to assess the quality-of-life (QoL) in the long-term postoperative period with respect to the used cerebral protection method. In a prospective, randomized study, 58 patients with chronic type I aortic dissection who underwent ascending aorta and aortic arch replacement surgery were included. Patients were allocated in two groups: 29 patients who underwent surgery under moderate hypothermia (24°C) combined with ACP and 29 patients who underwent surgery under DHCA (18°C) with craniocerebral hypothermia. The regional hemoglobin oxygen saturation (rSO2, %) were compared during surgery, neurological complications were analyzed during the early postoperative period, QoL was compared in the long-term postoperative period (1-year follow-up). During the early postoperative period, 37.9% of patients in the DHCA group exhibited neurological complications, compared with 13.8% of those in the ACP group (p < .05). The risk of neurological complications in the early postoperative period was dependent on the extent of rSO2 decrease during circulatory arrest. In the ACP group, rSO2 decreased by ≤17% from baseline during circulatory arrest. In the DHCA group, a more profound decrease in rSO2 (>30%) was recorded (p < .05). QoL in the long-term period after surgery improved, but it was not dependent on the cerebral protection method used during surgery. ACP during aortic replacement demonstrated the most advanced properties of cerebral protection that can be evidenced by a lesser degree of neurological complications, compared with patients who underwent surgery under conditions of DHCA. QoL after surgery was not dependent on the

Strength Training for Adolescents with cerebral palsy (STAR): study protocol of a randomised controlled trial to determine the feasibility, acceptability and efficacy of resistance training for adolescents with cerebral palsy.

PubMed

Ryan, Jennifer M; Theis, Nicola; Kilbride, Cherry; Baltzopoulos, Vasilios; Waugh, Charlie; Shortland, Adam; Lavelle, Grace; Noorkoiv, Marika; Levin, Wendy; Korff, Thomas

2016-10-04

Gait is inefficient in children with cerebral palsy, particularly as they transition to adolescence. Gait inefficiency may be associated with declines in gross motor function and participation among adolescents with cerebral palsy. Resistance training may improve gait efficiency through a number of biomechanical and neural mechanisms. The aim of the Strength Training for Adolescents with cerebral palsy (STAR) trial is to evaluate the effect of resistance training on gait efficiency, activity and participation in adolescents with cerebral palsy. We also aim to determine the biomechanical and neural adaptations that occur following resistance training and evaluate the feasibility and acceptability of such an intervention for adolescents with cerebral palsy. 60 adolescents (Gross Motor Function Classification System level I-III) will be randomised to a 10-week resistance training group or a usual care control group according to a computer-generated random schedule. The primary outcome is gait efficiency. Secondary outcomes are habitual physical activity, participation, muscle-tendon mechanics and gross motor function. General linear models will be used to evaluate differences in continuous data between the resistance training and usual care groups at 10 and 22 weeks, respectively. A process evaluation will be conducted alongside the intervention. Fidelity of the resistance training programme to trial protocol will be quantified by observations of exercise sessions. Semistructured interviews will be conducted with participants and physiotherapists following the resistance training programme to determine feasibility and acceptability of the programme. This trial has ethical approval from Brunel University London's Department of Clinical Sciences' Research Ethics Committee and the National Research Ethics Service (NRES) Committee London-Surrey Borders. The results of the trial will be submitted for publication in academic journals, presented at conferences and

EFFECT OF PREGNANCY ON AUTOREGULATION OF CEREBRAL BLOOD FLOW IN ANTERIOR VERSUS POSTERIOR CEREBRUM

PubMed Central

Cipolla, Marilyn J.; Bishop, Nicole; Chan, Siu-Lung

2012-01-01

Severe pre/eclampsia are associated with brain edema that forms preferentially in the posterior cerebral cortex possibly due to decreased sympathetic innervation of posterior cerebral arteries and less effective autoregulation during acute hypertension. In the present study, we examined the effect of pregnancy on the effectiveness of cerebral blood flow autoregulation using laser Doppler flowmetry and edema formation by wet:dry weight in acute hypertension induced by phenylephrine infusion in the anterior and posterior cerebrum from nonpregnant (n=8) and late-pregnant (n=6) Sprague Dawley rats. In addition, we compared the effect of pregnancy on sympathetic innervation by tyrosine hydroxylase staining of posterior and middle cerebral arteries (n=5–6/group) and endothelial and neuronal nitric oxide synthase expression using quantitative polymerase chain reaction (n=3/group). In nonpregnant animals, there was no difference in autoregulation between anterior and posterior cerebrum. However, in late-pregnant animals, the threshold of cerebral blood flow autoregulation was shifted to lower pressures in the posterior cerebrum, which was associated with increased neuronal nitric oxide synthase expression in the posterior cerebral cortex vs. anterior. Compared to the nonpregnant state, pregnancy increased the threshold of autoregulation in both brain regions that was related to decreased expression of endothelial nitric oxide synthase. Lastly, acute hypertension during pregnancy caused greater edema formation in both brain cortices that was not due to changes in sympathetic innervation. These findings suggest that although pregnancy shifted the cerebral blood flow autoregulatory curve to higher pressures in both the anterior and posterior cortices, it did not protect from edema during acute hypertension. PMID:22824983

Effect of pregnancy on autoregulation of cerebral blood flow in anterior versus posterior cerebrum.

PubMed

Cipolla, Marilyn J; Bishop, Nicole; Chan, Siu-Lung

2012-09-01

Severe preeclampsia and eclampsia are associated with brain edema that forms preferentially in the posterior cerebral cortex possibly because of decreased sympathetic innervation of posterior cerebral arteries and less effective autoregulation during acute hypertension. In the present study, we examined the effect of pregnancy on the effectiveness of cerebral blood flow autoregulation using laser Doppler flowmetry and edema formation by wet:dry weight in acute hypertension induced by phenylephrine infusion in the anterior and posterior cerebrum from nonpregnant (n=8) and late-pregnant (n=6) Sprague-Dawley rats. In addition, we compared the effect of pregnancy on sympathetic innervation by tyrosine hydroxylase staining of posterior and middle cerebral arteries (n=5-6 per group) and endothelial and neuronal NO synthase expression using quantitative PCR (n=3 per group). In nonpregnant animals, there was no difference in autoregulation between the anterior and posterior cerebrum. However, in late-pregnant animals, the threshold of cerebral blood flow autoregulation was shifted to lower pressures in the posterior cerebrum, which was associated with increased neuronal NO synthase expression in the posterior cerebral cortex versus anterior. Compared with the nonpregnant state, pregnancy increased the threshold of autoregulation in both brain regions that was related to decreased expression of endothelial NO synthase. Lastly, acute hypertension during pregnancy caused greater edema formation in both brain cortices that was not attributed to changes in sympathetic innervation. These findings suggest that, although pregnancy shifted the cerebral blood flow autoregulatory curve to higher pressures in both the anterior and posterior cortices, it did not protect from edema during acute hypertension.

Dipeptidyl peptidase IV, aminopeptidase N and DPIV/APN-like proteases in cerebral ischemia

PubMed Central

2012-01-01

Background Cerebral inflammation is a hallmark of neuronal degeneration. Dipeptidyl peptidase IV, aminopeptidase N as well as the dipeptidyl peptidases II, 8 and 9 and cytosolic alanyl-aminopeptidase are involved in the regulation of autoimmunity and inflammation. We studied the expression, localisation and activity patterns of these proteases after endothelin-induced occlusion of the middle cerebral artery in rats, a model of transient and unilateral cerebral ischemia. Methods Male Sprague-Dawley rats were used. RT-PCR, immunohistochemistry and protease activity assays were performed at different time points, lasting from 2 h to 7 days after cerebral ischemia. The effect of protease inhibitors on ischemia-dependent infarct volumes was quantified 7 days post middle cerebral artery occlusion. Statistical analysis was conducted using the t-test. Results Qualitative RT-PCR revealed these proteases in ipsilateral and contralateral cortices. Dipeptidyl peptidase II and aminopeptidase N were up-regulated ipsilaterally from 6 h to 7 days post ischemia, whereas dipeptidyl peptidase 9 and cytosolic alanyl-aminopeptidase were transiently down-regulated at day 3. Dipeptidyl peptidase 8 and aminopeptidase N immunoreactivities were detected in cortical neurons of the contralateral hemisphere. At the same time point, dipeptidyl peptidase IV, 8 and aminopeptidase N were identified in activated microglia and macrophages in the ipsilateral cortex. Seven days post artery occlusion, dipeptidyl peptidase IV immunoreactivity was found in the perikarya of surviving cortical neurons of the ipsilateral hemisphere, whereas their nuclei were dipeptidyl peptidase 8- and amino peptidase N-positive. At the same time point, dipeptidyl peptidase IV, 8 and aminopeptidase N were targeted in astroglial cells. Total dipeptidyl peptidase IV, 8 and 9 activities remained constant in both hemispheres until day 3 post experimental ischemia, but were increased (+165%) in the ipsilateral cortex at day 7

The relationship between depression and regional cerebral blood flow in Parkinson's disease and the effect of selegiline treatment.

PubMed

Imamura, K; Okayasu, N; Nagatsu, T

2011-07-01

We examined the relationship between severity of depression in Parkinson's disease (PD) and regional cerebral blood flow (rCBF) using single photon emission computed tomography (SPECT) and the reaction to levodopa-selegiline combination therapy. We evaluated 52 patients with PD and nine age-matched controls with SPECT and the Unified Parkinson's Disease Rating Scale (UPDRS) part III, Mini-Mental State Examination (MMSE), and Beck Depression Inventory (BDI) to evaluate depression severity and its connection with rCBF. Furthermore, we examined rCBF in patients with PD treated with levodopa with or without selegiline. A significant fall in rCBF was observed in the bilateral posterior cingulate, hippocampus, and cuneus and the superior parietal and primary visual areas in PD patients with minor depression and in all regions in those with major depression. Elevations in UPDRS part III and BDI scores and falls in MMSE scores were of significantly lower magnitude in the levodopa-selegiline group than in the levodopa group. Whole brain rCBF fell significantly less in the levodopa-selegiline group than in the levodopa group. These results indicate that selegiline controlled not only worsening of motor function and cognitive function in PD but also aggravation of minor depression, and restrained a fall in whole brain rCBF. © 2010 John Wiley & Sons A/S.

Evaluation of cerebral oxygenation and perfusion with conversion from an arterial-to-systemic shunt circulation to the bidirectional Glenn circulation in patients with univentricular cardiac abnormalities.

PubMed

Bertolizio, Gianluca; DiNardo, James A; Laussen, Peter C; Polito, Angelo; Pigula, Frank A; Zurakowski, David; Kussman, Barry D

2015-02-01

Superior vena cava pressure after the bidirectional Glenn operation usually is higher than that associated with the preceding shunt-dependent circulation. The aim of the present study was to determine whether the acute elevation in central venous pressure was associated with changes in cerebral oxygenation and perfusion. Single-center prospective, observational cohort study. Academic children's hospital. Infants with single-ventricle lesions and surgically placed systemic-to-pulmonary artery shunts undergoing the bidirectional Glenn operation. Near-infrared spectroscopy and transcranial Doppler sonography were used to measure regional cerebral oxygen saturation and cerebral blood flow velocity. Mean differences in regional cerebral oxygen saturation and cerebral blood flow velocity before anesthetic induction and shortly before hospital discharge were compared using the F-test in repeated measures analysis of variance. In the 24 infants studied, mean cerebral oxygen saturation increased from 49%±2% to 57%±2% (p = 0.007), mean cerebral blood flow velocity decreased from 57±4 cm/s to 47±4 cm/s (p = 0.026), and peak systolic cerebral blood flow velocity decreased from 111±6 cm/s to 99±6 cm/s (p = 0.046) after the bidirectional Glenn operation. Mean central venous pressure was 8±2 mmHg postinduction of anesthesia and 14±4 mmHg on the first postoperative day and was not associated with a change in cerebral perfusion pressure (p = 0.35). The bidirectional Glenn operation in infants with a shunt-dependent circulation is associated with an improvement in cerebral oxygenation, and the lower cerebral blood flow velocity is likely a response of intact cerebral autoregulation. Copyright © 2014 Elsevier Inc. All rights reserved.

Regional cerebral blood flow (rCBF) in schizophrenia during verbal memory activation: a 99mTc-HMPAO single photon emission tomography (SPET) study.

PubMed

Busatto, G F; Costa, D C; Ell, P J; Pilowsky, L S; David, A S; Kerwin, R W

1994-05-01

Regional cerebral blood flow (rCBF) was investigated in a group of medicated DSM-III-R schizophrenic patients and age, sex and handedness matched normal volunteers using a split-dose 99mTc-HMPAO Single Photon Emission Tomography (SPET) protocol. Measures were taken during the performance of a verbal memory task aimed at activating the left medial temporal lobe, a region repeatedly suggested to be structurally abnormal in schizophrenia. In normal subjects, the performance of the task was associated with significant rCBF increases in the left medial temporal, left inferior frontal and anterior cingulate cortices, and right cerebellum. Despite their significantly poorer performance on the memory task, the degree of medial temporal activation measured in the schizophrenic patients was not significantly different from that found in the control group. This finding suggests that memory deficits in schizophrenia do not necessarily imply failure to activate the left medial temporal lobe as assessed by 99mTc-HMPAO SPET.

Effects of dexmedetomidine on microregional O2 balance during reperfusion after focal cerebral ischemia.

PubMed

Chi, Oak Z; Grayson, Jeremy; Barsoum, Sylviana; Liu, Xia; Dinani, Aliraza; Weiss, Harvey R

2015-01-01

This study was performed to determine whether there is an association between microregional O2 balance and neuronal survival in cerebral ischemia-reperfusion using dexmedetomidine, an α2-adrenoreceptor agonist and a sedative. Rats were subjected to 1 hour middle cerebral artery occlusion and a 2-hour reperfusion. During reperfusion, normal saline (n = 14) or dexmedetomidine 1 μg/kg/minute (n = 14) was infused intravenously. At 2 hours of reperfusion, regional cerebral blood flow using (14)C-iodoantipyrine autoradiography, microregional arterial and venous (20-60 μm in diameter) O2 saturation (SvO2) using cryomicrospectrophotometry, and the size of cortical infarction were determined. Ischemia-reperfusion decreased microregional SvO2 (52.9 ± 3.7% vs. 61.1 ± .6%, P < .005) with increased variation or heterogeneity (P < .0001) with similar regional cerebral blood flow and O2 consumption. Dexmedetomidine during reperfusion decreased the heterogeneity of SvO2 that was analyzed with an analysis of variance (P < .01) and reported as coefficient of variation (100 × standard deviation/Mean) (11.8 vs. 16.4). The number of veins with O2 saturation less than 50% decreased with dexmedetomidine (13/80 vs. 27/81, P < .01). The percentage of cortical infarct in total cortex was smaller with dexmedetomidine (8.3 ± 2.2% vs. 12.6 ± 1.5%, P < .005). In the cerebral ischemic reperfused cortex, dexmedetomidine decreased the heterogeneity of SvO2 and the number of small veins with low O2 saturation suggesting improved microregional O2 supply/consumption balance. The improvement was accompanied by the reduced size of cortical infarction. Copyright © 2015 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Tetrahedral and polyhedral mesh evaluation for cerebral hemodynamic simulation--a comparison.

PubMed

Spiegel, Martin; Redel, Thomas; Zhang, Y; Struffert, Tobias; Hornegger, Joachim; Grossman, Robert G; Doerfler, Arnd; Karmonik, Christof

2009-01-01

Computational fluid dynamic (CFD) based on patient-specific medical imaging data has found widespread use for visualizing and quantifying hemodynamics in cerebrovascular disease such as cerebral aneurysms or stenotic vessels. This paper focuses on optimizing mesh parameters for CFD simulation of cerebral aneurysms. Valid blood flow simulations strongly depend on the mesh quality. Meshes with a coarse spatial resolution may lead to an inaccurate flow pattern. Meshes with a large number of elements will result in unnecessarily high computation time which is undesirable should CFD be used for planning in the interventional setting. Most CFD simulations reported for these vascular pathologies have used tetrahedral meshes. We illustrate the use of polyhedral volume elements in comparison to tetrahedral meshing on two different geometries, a sidewall aneurysm of the internal carotid artery and a basilar bifurcation aneurysm. The spatial mesh resolution ranges between 5,119 and 228,118 volume elements. The evaluation of the different meshes was based on the wall shear stress previously identified as a one possible parameter for assessing aneurysm growth. Polyhedral meshes showed better accuracy, lower memory demand, shorter computational speed and faster convergence behavior (on average 369 iterations less).

New auto-segment method of cerebral hemorrhage

NASA Astrophysics Data System (ADS)

Wang, Weijiang; Shen, Tingzhi; Dang, Hua

2007-12-01

A novel method for Computerized tomography (CT) cerebral hemorrhage (CH) image automatic segmentation is presented in the paper, which uses expert system that models human knowledge about the CH automatic segmentation problem. The algorithm adopts a series of special steps and extracts some easy ignored CH features which can be found by statistic results of mass real CH images, such as region area, region CT number, region smoothness and some statistic CH region relationship. And a seven steps' extracting mechanism will ensure these CH features can be got correctly and efficiently. By using these CH features, a decision tree which models the human knowledge about the CH automatic segmentation problem has been built and it will ensure the rationality and accuracy of the algorithm. Finally some experiments has been taken to verify the correctness and reasonable of the automatic segmentation, and the good correct ratio and fast speed make it possible to be widely applied into practice.

Quantitative cerebral perfusion assessment using microscope-integrated analysis of intraoperative indocyanine green fluorescence angiography versus positron emission tomography in superficial temporal artery to middle cerebral artery anastomosis.

PubMed

Kobayashi, Shinya; Ishikawa, Tatsuya; Tanabe, Jun; Moroi, Junta; Suzuki, Akifumi

2014-01-01

Intraoperative qualitative indocyanine green (ICG) angiography has been used in cerebrovascular surgery. Hyperperfusion may lead to neurological complications after superficial temporal artery to middle cerebral artery (STA-MCA) anastomosis. The purpose of this study is to quantitatively evaluate intraoperative cerebral perfusion using microscope-integrated dynamic ICG fluorescence analysis, and to assess whether this value predicts hyperperfusion syndrome (HPS) after STA-MCA anastomosis. Ten patients undergoing STA-MCA anastomosis due to unilateral major cerebral artery occlusive disease were included. Ten patients with normal cerebral perfusion served as controls. The ICG transit curve from six regions of interest (ROIs) on the cortex, corresponding to ROIs on positron emission tomography (PET) study, was recorded. Maximum intensity (IMAX), cerebral blood flow index (CBFi), rise time (RT), and time to peak (TTP) were evaluated. RT/TTP, but not IMAX or CBFi, could differentiate between control and study subjects. RT/TTP correlated (|r| = 0.534-0.807; P < 0.01) with mean transit time (MTT)/MTT ratio in the ipsilateral to contralateral hemisphere by PET study. Bland-Altman analysis showed a wide limit of agreement between RT and MTT and between TTP and MTT. The ratio of RT before and after bypass procedures was significantly lower in patients with postoperative HPS than in patients without postoperative HPS (0.60 ± 0.032 and 0.80 ± 0.056, respectively; P = 0.017). The ratio of TTP was also significantly lower in patients with postoperative HPS than in patients without postoperative HPS (0.64 ± 0.081 and 0.85 ± 0.095, respectively; P = 0.017). Time-dependent intraoperative parameters from the ICG transit curve provide quantitative information regarding cerebral circulation time with quality and utility comparable to information obtained by PET. These parameters may help predict the occurrence of postoperative HPS.

A multiparametric evaluation of regional brain damage in patients with primary progressive multiple sclerosis.

PubMed

Ceccarelli, Antonia; Rocca, Maria A; Valsasina, Paola; Rodegher, Mariaemma; Pagani, Elisabetta; Falini, Andrea; Comi, Giancarlo; Filippi, Massimo

2009-09-01

The purpose of this study is to define the topographical distribution of gray matter (GM) and white matter (WM) damage in patients with primary progressive multiple sclerosis (PPMS), using a multiparametric MR-based approach. Using a 3 Tesla scanner, dual-echo, 3D fast-field echo (FFE), and diffusion tensor (DT) MRI scans were acquired from 18 PPMS patients and 17 matched healthy volunteers. An optimized voxel-based (VB) analysis was used to investigate the patterns of regional GM density changes and to quantify GM and WM diffusivity alterations of the entire brain. In PPMS patients, GM atrophy was found in the thalami and the right insula, while mean diffusivity (MD) changes involved several cortical-subcortical structures in all cerebral lobes and the cerebellum. An overlap between decreased WM fractional anisotropy (FA) and increased WM MD was found in the corpus callosum, the cingulate gyrus, the left short temporal fibers, the right short frontal fibers, the optic radiations, and the middle cerebellar peduncles. Selective MD increase, not associated with FA decrease, was found in the internal capsules, the corticospinal tracts, the superior longitudinal fasciculi, the fronto-occipital fasciculi, and the right cerebral peduncle. A discrepancy was found between regional WM diffusivity changes and focal lesions because several areas had DT MRI abnormalities but did not harbor T2-visible lesions. Our study allowed to detect tissue damage in brain areas associated with motor and cognitive functions, which are known to be impaired in PPMS patients. Combining regional measures derived from different MR modalities may be a valuable tool to improve our understanding of PPMS pathophysiology. 2009 Wiley-Liss, Inc.

The protocadherin 11X/Y (PCDH11X/Y) gene pair as determinant of cerebral asymmetry in modern Homo sapiens.

PubMed

Priddle, Thomas H; Crow, Timothy J

2013-06-01

Annett's right-shift theory proposes that human cerebral dominance (the functional and anatomical asymmetry or torque along the antero-posterior axis) and handedness are determined by a single "right-shift" gene. Familial transmission of handedness and specific deviations of cerebral dominance in sex chromosome aneuploidies implicate a locus within an X-Y homologous region of the sex chromosomes. The Xq21.3/Yp11.2 human-specific region of homology includes the protocadherin 11X/Y (PCDH11X/Y) gene pair, which encode cell adhesion molecules subject to accelerated evolution following the separation of the human and chimpanzee lineages six million years ago. PCDH11X and PCDH11Y, differentially regulated by retinoic acid, are highly expressed in the ventricular zone, subplate, and cortical plate of the developing cerebral cortex. Both proteins interact with β-catenin, a protein that plays a role in determining axis formation and regulating cortical size. In this way, the PCDH11X/Y gene pair determines cerebral asymmetry by initiating the right shift in Homo sapiens. © 2013 New York Academy of Sciences.