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Sample records for absent corpus callosum

  1. Bilingual Corpus Callosum Variability

    ERIC Educational Resources Information Center

    Coggins, Porter E., III.; Kennedy, Teresa J.; Armstrong, Terry A.

    2004-01-01

    Magnetic resonance imaging was used to produce midsagittal images of the corpus callosum of 19 right-handed adult male and female subjects. The preliminary findings of this study indicate that significant adaptation in the anterior midbody of the corpus callosum has occurred to accommodate multiple language capacity in bilingual individuals…

  2. Corpus Callosum Volume and Neurocognition in Autism

    ERIC Educational Resources Information Center

    Keary, Christopher J.; Minshew, Nancy J.; Bansal, Rahul; Goradia, Dhruman; Fedorov, Serguei; Keshavan, Matcheri S.; Hardan, Antonio Y.

    2009-01-01

    The corpus callosum has recently been considered as an index of interhemispheric connectivity. This study applied a novel volumetric method to examine the size of the corpus callosum in 32 individuals with autism and 34 age-, gender- and IQ-matched controls and to investigate the relationship between this structure and cognitive measures linked to…

  3. Corpus Callosum MR Image Classification

    NASA Astrophysics Data System (ADS)

    Elsayed, A.; Coenen, F.; Jiang, C.; García-Fiñana, M.; Sluming, V.

    An approach to classifying Magnetic Resonance (MR) image data is described. The specific application is the classification of MRI scan data according to the nature of the corpus callosum, however the approach has more general applicability. A variation of the “spectral segmentation with multi-scale graph decomposition” mechanism is introduced. The result of the segmentation is stored in a quad-tree data structure to which a weighted variation (also developed by the authors) of the gSpan algorithm is applied to identify frequent sub-trees. As a result the images are expressed as a set frequent sub-trees. There may be a great many of these and thus a decision tree based feature reduction technique is applied before classification takes place. The results show that the proposed approach performs both efficiently and effectively, obtaining a classification accuracy of over 95% in the case of the given application.

  4. Fiber composition of the human corpus callosum.

    PubMed

    Aboitiz, F; Scheibel, A B; Fisher, R S; Zaidel, E

    1992-12-11

    The densities of fibers of different sizes were calculated in ten regions of the corpus callosum of twenty human brains (ten females, ten males). Light microscopic examination revealed a consistent pattern of regional differentiation of fiber types in the corpus callosum. Thin fibers are most dense in the anterior corpus callosum (genu), and decrease in density posteriorly towards the posterior midbody, where they reach a minimum. Towards the posterior corpus callosum (splenium), the density of thin fibers increases again, but in the posterior pole of the callosum the density decreases locally. Large-diameter fibers show a pattern complementary to that of thin fibers, having a peak of density in the posterior midbody and a local increase of density in the posterior pole of the corpus callosum. Across subjects, the overall density of callosal fibers had no significant correlation with callosal area and an increased callosal area indicated an increased total number of fibers crossing through. Considering different fiber sizes, this was only true for small diameter fibers, whose large majority is believed to interconnect association cortex. No sex differences in fiber composition of the corpus callosum were found.

  5. Corpus Callosum Area in Children and Adults with Autism

    ERIC Educational Resources Information Center

    Prigge, Molly B. D.; Lange, Nicholas; Bigler, Erin D.; Merkley, Tricia L.; Neeley, E. Shannon; Abildskov, Tracy J.; Froehlich, Alyson L.; Nielsen, Jared A.; Cooperrider, Jason R.; Cariello, Annahir N.; Ravichandran, Caitlin; Alexander, Andrew L.; Lainhart, Janet E.

    2013-01-01

    Despite repeated findings of abnormal corpus callosum structure in autism, the developmental trajectories of corpus callosum growth in the disorder have not yet been reported. In this study, we examined corpus callosum size from a developmental perspective across a 30-year age range in a large cross-sectional sample of individuals with autism…

  6. Quantitative assessment of corpus callosum morphology in periventricular nodular heterotopia.

    PubMed

    Pardoe, Heath R; Mandelstam, Simone A; Hiess, Rebecca Kucharsky; Kuzniecky, Ruben I; Jackson, Graeme D

    2015-01-01

    We investigated systematic differences in corpus callosum morphology in periventricular nodular heterotopia (PVNH). Differences in corpus callosum mid-sagittal area and subregional area changes were measured using an automated software-based method. Heterotopic gray matter deposits were automatically labeled and compared with corpus callosum changes. The spatial pattern of corpus callosum changes were interpreted in the context of the characteristic anterior-posterior development of the corpus callosum in healthy individuals. Individuals with periventricular nodular heterotopia were imaged at the Melbourne Brain Center or as part of the multi-site Epilepsy Phenome Genome project. Whole brain T1 weighted MRI was acquired in cases (n=48) and controls (n=663). The corpus callosum was segmented on the mid-sagittal plane using the software "yuki". Heterotopic gray matter and intracranial brain volume was measured using Freesurfer. Differences in corpus callosum area and subregional areas were assessed, as well as the relationship between corpus callosum area and heterotopic GM volume. The anterior-posterior distribution of corpus callosum changes and heterotopic GM nodules were quantified using a novel metric and compared with each other. Corpus callosum area was reduced by 14% in PVNH (p=1.59×10(-9)). The magnitude of the effect was least in the genu (7% reduction) and greatest in the isthmus and splenium (26% reduction). Individuals with higher heterotopic GM volume had a smaller corpus callosum. Heterotopic GM volume was highest in posterior brain regions, however there was no linear relationship between the anterior-posterior position of corpus callosum changes and PVNH nodules. Reduced corpus callosum area is strongly associated with PVNH, and is probably associated with abnormal brain development in this neurological disorder. The primarily posterior corpus callosum changes may inform our understanding of the etiology of PVNH. Our results suggest that

  7. Agenesis of the Corpus Callosum and Generalized Epilepsy.

    PubMed

    Ilik, Faik; Bilgilisoy, Ugur T

    2015-07-01

    The corpus callosum is the main band of interhemispheric axonal fibers in the human brain. Corpus callosum agenesis has widely varying symptoms, mainly associated with epilepsy, cognitive failure, and different neuropsychiatric disorders. Our case of corpus callosum agenesis includes eyelid myoclonia with absences. In the literature, there is no reported case of this combination. We report this case because it is rare, and relevant for the understanding of interhemispheric communications, based on our electrophysiological findings.

  8. Delusional Disorder in a Patient with Corpus Callosum Agenesis.

    PubMed

    Bhatia, M S; Saha, Rashmita; Doval, Nimisha

    2016-12-01

    Agenesis of corpus callosum is rare and associated neuropsychiatric abnormalities reported are epilepsy, Asperger's syndrome, learning problems, depression, schizophrenia, conduct disorder and conversion symptoms. Schizophrenia is the most common psychiatric disorder reported among corpus callosum agenesis. We report a rare case of delusional disorder with corpus callosum agenesis and seizure disorder. The patient presented with delusions of persecution towards younger brother and mother, disturbed sleep and reduced appetite. She had a history of seizure disorder of ten years duration, which was controlled with carbamazepine and levetiracetam. Neurological examination was normal. On MRI, corpus callosum agenesis was detected. She was put on an atypical antipsychotic quetiapine to which her psychiatric symptoms responded completely.

  9. Educational Implications for Agenesis of the Corpus Callosum.

    ERIC Educational Resources Information Center

    Ritter, Shirley A.

    This case study evaluates the case of a 20-year-old young Australian adult born with agenesis of the corpus callosum, the area of the brain uniting the hemispheres. Deficits commonly associated with agenesis of the corpus callosum are mental retardation, motor involvement, seizure activity, and lateral transfer difficulties. The report: (1)…

  10. The Corpus Callosum and Reading: An MRI Volumetric Study

    ERIC Educational Resources Information Center

    Fine, Jodene Goldenring

    2006-01-01

    Researchers have long been interested in the role of the corpus callosum in reading disorder, but existing studies have yielded inconsistent results. Some have found larger corpus callosa in those with reading disorder, others have found smaller corpus callosa, and some have found no differences in the corpus callosa of persons with and without…

  11. Corpus callosum involvement and postoperative outcomes of patients with gliomas.

    PubMed

    Chen, Ko-Ting; Wu, Tai-Wei Erich; Chuang, Chi-Cheng; Hsu, Yung-Hsin; Hsu, Peng-Wei; Huang, Yin-Cheng; Lin, Tzu-Kang; Chang, Chen-Nen; Lee, Shih-Tseng; Wu, Chieh-Tsai; Tseng, Chen-Kan; Wang, Chun-Chieh; Pai, Ping-Ching; Wei, Kuo-Chen; Chen, Pin-Yuan

    2015-09-01

    Corpus callosum involvement is associated with poorer survival in high grade glioma (HGG), but the prognostic value in low grade glioma (LGG) is unclear. To determine the prognostic impact of corpus callosum involvement on progression free survival (PFS) and overall survival (OS) in HGG and LGG, the records of 233 glioma patients treated from 2008 to 2011 were retrospectively reviewed. Preoperative magnetic resonance (MR) images were used to identify corpus callosum involvement. Age, sex, preoperative Karnofsky performance scale, postoperative Eastern Cooperative Oncology Group (ECOG) score and extent of resection (EOR) were evaluated with respect to PFS and OS. The incidence of corpus callosum involvement was similar among HGG (14 %) and LGG (14.5 %). Univariate analysis revealed that PFS and OS were significantly shorter in both WHO grade II and grade IV glioma with corpus callosum involvement (both, p < 0.05). Multivariate analysis showed that grade II glioma with corpus callosum involvement have shorter PFS (p = 0.03), while EOR, instead of corpus callosum involvement (p = 0.16), was an independent factor associated with PFS in grade IV glioma (p < 0.05). Corpus callosum involvement was no longer significantly associated with OS after adjusting age, gender, EOR, preoperative and postoperative performance status (p = 0.16, 0.17 and 0.56 in grade II, III and IV gliomas, respectively). Corpus callosum involvement happened in both LGG and HGG, and is associated with lower EOR and higher postoperative ECOG score both in LGG and HGG. Corpus callosum involvement tends to be an independent prognostic factor for PFS in LGG, but not for OS in LGG or in HGG.

  12. [Modern diagnostic of agenesis of the corpus callosum in children].

    PubMed

    Milovanova, O A; Alikhanov, A A; Tambiev, I E; Tarakanova, T Yu

    2017-01-01

    Observations of the authors regarding main MRI symptoms of agenesis of the corpus callosum (ACC) and literature review on the structure of the corpus callosum in normalcy and pathology are presented. The authors emphasize that some cases of isolated ACC has been found during routine prenatal ultrasound examination. In this regard, prenatal MRI is more effective. In 74% patients with ACC, MRI results are consistent with the results of ultrasound and CT. MRI has advantages in the differentiation of inherited corpus callosum malformation as well as concomitant CNS abnormalities.

  13. Automatic recognition of corpus callosum from sagittal brain MR images

    NASA Astrophysics Data System (ADS)

    Lee, Chulhee; Unser, Michael A.; Ketter, Terence A.

    1995-08-01

    We propose a new method to find the corpus callosum from sagittal brain MR images automatically. First, we calculate the statistical characteristics of the corpus callosum and obtain shape information. The recognition algorithm consists of two stages: extracting regions satisfying the statistical characteristics (gray level distribtuions) of the corpus callosum, and finding a region matching the shape information. An innovative feature of the algorithm is that we adaptively relax the statistical requirement until we find a region matching the shape information. In order to match the shape information, we propose a new directed window region growing algorithm instead of using conventional contour matching. Experiments show promising results.

  14. Cavernous angioma of the corpus callosum presenting with acute psychosis.

    PubMed

    Pavesi, Giacomo; Causin, Francesco; Feletti, Alberto

    2014-01-01

    Psychiatric symptoms may occasionally be related to anatomic alterations of brain structures. Particularly, corpus callosum lesions seem to play a role in the change of patients' behavior. We present a case of a sudden psychotic attack presumably due to a hemorrhagic cavernous angioma of the corpus callosum, which was surgically removed with complete resolution of symptoms. Although a developmental defect like agenesis or lipoma is present in the majority of these cases, a growing lesion of the corpus callosum can rarely be the primary cause. Since it is potentially possible to cure these patients, clinicians should be aware of this association.

  15. Corpus Callosum Shape Analysis with Application to Dyslexia

    PubMed Central

    Casanova, Manuel F.; El-Baz, Ayman; Elnakib, Ahmed; Giedd, Jay; Rumsey, Judith M.; Williams, Emily L.; Switala, Andrew E.

    2012-01-01

    Morphometric studies of the corpus callosum suggest its involvement in a number of psychiatric conditions. In the present study we introduce a novel pattern recognition technique that offers a point-by-point shape descriptor of the corpus callosum. The method uses arc lengths of electric field lines in order to avoid discontinuities caused by folding anatomical contours. We tested this technique by comparing the shape of the corpus callosum in a series of dyslexic men (n = 16) and age-matched controls (n = 14). The results indicate a generalized increase in size of the corpus callosum in dyslexia with a concomitant diminution at its rostral and caudal poles. The reported shape analysis and 2D-reconstruction provide information of anatomical importance that would otherwise passed unnoticed when analyzing size information alone. PMID:22545196

  16. Anatomy of corpus callosum in prenatally malnourished rats.

    PubMed

    Olivares, Ricardo; Morgan, Carlos; Pérez, Hernán; Hernández, Alejandro; Aboitiz, Francisco; Soto-Moyano, Rubén; Gil, Julio; Ortiz, Alexis; Flores, Osvaldo; Gimeno, Miguel; Laborda, Jesús

    2012-01-01

    The effect of prenatal malnutrition on the anatomy of the corpus callosum was assessed in adult rats (45-52 days old). In the prenatally malnourished animals we observed a significant reduction of the corpus callosum total area, partial areas, and perimeter, as compared with normal animals. In addition, the splenium of corpus callosum (posterior fifth) showed a significant decrease of fiber diameters in the myelinated fibers without changing density. There was also a significant decrease in diameter and a significant increase in density of unmyelinated fibers. Measurements of perimeter's fractal dimensions from sagittal sections of the brain and corpus callosum did not show significant differences between malnourished and control animals. These findings indicate that cortico-cortical connections are vulnerable to the prenatal malnutrition, and suggest this may affect interhemispheric conduction velocity, particularly in visual connections (splenium).

  17. Delusional Disorder in a Patient with Corpus Callosum Agenesis

    PubMed Central

    Saha, Rashmita; Doval, Nimisha

    2016-01-01

    Agenesis of corpus callosum is rare and associated neuropsychiatric abnormalities reported are epilepsy, Asperger’s syndrome, learning problems, depression, schizophrenia, conduct disorder and conversion symptoms. Schizophrenia is the most common psychiatric disorder reported among corpus callosum agenesis. We report a rare case of delusional disorder with corpus callosum agenesis and seizure disorder. The patient presented with delusions of persecution towards younger brother and mother, disturbed sleep and reduced appetite. She had a history of seizure disorder of ten years duration, which was controlled with carbamazepine and levetiracetam. Neurological examination was normal. On MRI, corpus callosum agenesis was detected. She was put on an atypical antipsychotic quetiapine to which her psychiatric symptoms responded completely. PMID:28208982

  18. Corpus Callosum Morphometrics in Young Children with Autism Spectrum Disorder

    ERIC Educational Resources Information Center

    Boger-Megiddo, Inbal; Shaw, Dennis W. W.; Friedman, Seth D.; Sparks, Bobbi F.; Artru, Alan A.; Giedd, Jay N.; Dawson, Geraldine; Dager, Stephen R.

    2006-01-01

    This study assessed digital corpus callosum cross sectional areas in 3-4 year olds with autism spectrum disorder (ASD) compared to typically developing (TD) and developmentally delayed (DD) children. Though not different in absolute size compared to TD, ASD callosums were disproportionately small adjusted for increased ASD cerebral volume. ASD…

  19. Interleukin-6, age, and corpus callosum integrity.

    PubMed

    Bettcher, Brianne M; Watson, Christa L; Walsh, Christine M; Lobach, Iryna V; Neuhaus, John; Miller, Joshua W; Green, Ralph; Patel, Nihar; Dutt, Shubir; Busovaca, Edgar; Rosen, Howard J; Yaffe, Kristine; Miller, Bruce L; Kramer, Joel H

    2014-01-01

    The contribution of inflammation to deleterious aging outcomes is increasingly recognized; however, little is known about the complex relationship between interleukin-6 (IL-6) and brain structure, or how this association might change with increasing age. We examined the association between IL-6, white matter integrity, and cognition in 151 community dwelling older adults, and tested whether age moderated these associations. Blood levels of IL-6 and vascular risk (e.g., homocysteine), as well as health history information, were collected. Processing speed assessments were administered to assess cognitive functioning, and we employed tract-based spatial statistics to examine whole brain white matter and regions of interest. Given the association between inflammation, vascular risk, and corpus callosum (CC) integrity, fractional anisotropy (FA) of the genu, body, and splenium represented our primary dependent variables. Whole brain analysis revealed an inverse association between IL-6 and CC fractional anisotropy. Subsequent ROI linear regression and ridge regression analyses indicated that the magnitude of this effect increased with age; thus, older individuals with higher IL-6 levels displayed lower white matter integrity. Finally, higher IL-6 levels were related to worse processing speed; this association was moderated by age, and was not fully accounted for by CC volume. This study highlights that at older ages, the association between higher IL-6 levels and lower white matter integrity is more pronounced; furthermore, it underscores the important, albeit burgeoning role of inflammatory processes in cognitive aging trajectories.

  20. Interleukin-6, Age, and Corpus Callosum Integrity

    PubMed Central

    Bettcher, Brianne M.; Watson, Christa L.; Walsh, Christine M.; Lobach, Iryna V.; Neuhaus, John; Miller, Joshua W.; Green, Ralph; Patel, Nihar; Dutt, Shubir; Busovaca, Edgar; Rosen, Howard J.; Yaffe, Kristine; Miller, Bruce L.; Kramer, Joel H.

    2014-01-01

    The contribution of inflammation to deleterious aging outcomes is increasingly recognized; however, little is known about the complex relationship between interleukin-6 (IL-6) and brain structure, or how this association might change with increasing age. We examined the association between IL-6, white matter integrity, and cognition in 151 community dwelling older adults, and tested whether age moderated these associations. Blood levels of IL-6 and vascular risk (e.g., homocysteine), as well as health history information, were collected. Processing speed assessments were administered to assess cognitive functioning, and we employed tract-based spatial statistics to examine whole brain white matter and regions of interest. Given the association between inflammation, vascular risk, and corpus callosum (CC) integrity, fractional anisotropy (FA) of the genu, body, and splenium represented our primary dependent variables. Whole brain analysis revealed an inverse association between IL-6 and CC fractional anisotropy. Subsequent ROI linear regression and ridge regression analyses indicated that the magnitude of this effect increased with age; thus, older individuals with higher IL-6 levels displayed lower white matter integrity. Finally, higher IL-6 levels were related to worse processing speed; this association was moderated by age, and was not fully accounted for by CC volume. This study highlights that at older ages, the association between higher IL-6 levels and lower white matter integrity is more pronounced; furthermore, it underscores the important, albeit burgeoning role of inflammatory processes in cognitive aging trajectories. PMID:25188448

  1. Morphometric changes of the corpus callosum in congenital blindness.

    PubMed

    Tomaiuolo, Francesco; Campana, Serena; Collins, D Louis; Fonov, Vladimir S; Ricciardi, Emiliano; Sartori, Giuseppe; Pietrini, Pietro; Kupers, Ron; Ptito, Maurice

    2014-01-01

    We examined the effects of visual deprivation at birth on the development of the corpus callosum in a large group of congenitally blind individuals. We acquired high-resolution T1-weighted MRI scans in 28 congenitally blind and 28 normal sighted subjects matched for age and gender. There was no overall group effect of visual deprivation on the total surface area of the corpus callosum. However, subdividing the corpus callosum into five subdivisions revealed significant regional changes in its three most posterior parts. Compared to the sighted controls, congenitally blind individuals showed a 12% reduction in the splenium, and a 20% increase in the isthmus and the posterior part of the body. A shape analysis further revealed that the bending angle of the corpus callosum was more convex in congenitally blind compared to the sighted control subjects. The observed morphometric changes in the corpus callosum are in line with the well-described cross-modal functional and structural neuroplastic changes in congenital blindness.

  2. Proteome dynamics during postnatal mouse corpus callosum development

    PubMed Central

    Son, Alexander I.; Fu, Xiaoqin; Suto, Fumikazu; Liu, Judy S.; Hashimoto-Torii, Kazue; Torii, Masaaki

    2017-01-01

    Formation of cortical connections requires the precise coordination of numerous discrete phases. This is particularly significant with regard to the corpus callosum, whose development undergoes several dynamic stages including the crossing of axon projections, elimination of exuberant projections, and myelination of established tracts. To comprehensively characterize the molecular events in this dynamic process, we set to determine the distinct temporal expression of proteins regulating the formation of the corpus callosum and their respective developmental functions. Mass spectrometry-based proteomic profiling was performed on early postnatal mouse corpus callosi, for which limited evidence has been obtained previously, using stable isotope of labeled amino acids in mammals (SILAM). The analyzed corpus callosi had distinct proteomic profiles depending on age, indicating rapid progression of specific molecular events during this period. The proteomic profiles were then segregated into five separate clusters, each with distinct trajectories relevant to their intended developmental functions. Our analysis both confirms many previously-identified proteins in aspects of corpus callosum development, and identifies new candidates in understudied areas of development including callosal axon refinement. We present a valuable resource for identifying new proteins integral to corpus callosum development that will provide new insights into the development and diseases afflicting this structure. PMID:28349996

  3. Agenesis of corpus callosum and frontotemporal dementia: a casual finding?

    PubMed

    Calabrò, Rocco Salvatore; Spadaro, Letteria; Marra, Angela; Balletta, Tina; Cammaroto, Simona; Bramanti, Placido

    2015-06-01

    Agenesis of corpus callosum (AgCC) is a congenital malformation characterized by total or partial absence of corpus callosum with a good neuropsychological profile. Frontotemporal dementia (FTD) is the third most common cause of cortical dementia, and it is characterized by alterations in personality and social relationship, often associated with deficits in attention, abstraction, planning, and problem solving. Herein, we report a case of a 73-year-old woman presenting with FTD associated with primary AgCC. The possible "causal or casual" relationship between these 2 different conditions should be investigated in large prospective studies.

  4. The Contribution of the Corpus Callosum to Language Lateralization

    PubMed Central

    Hinkley, Leighton B.N.; Marco, Elysa J.; Brown, Ethan G.; Bukshpun, Polina; Gold, Jacquelyn; Hill, Susanna; Findlay, Anne M.; Jeremy, Rita J.; Wakahiro, Mari L.; Barkovich, A. James; Mukherjee, Pratik

    2016-01-01

    The development of hemispheric lateralization for language is poorly understood. In one hypothesis, early asymmetric gene expression assigns language to the left hemisphere. In an alternate view, language is represented a priori in both hemispheres and lateralization emerges via cross-hemispheric communication through the corpus callosum. To address this second hypothesis, we capitalized on the high temporal and spatial resolution of magnetoencephalographic imaging to measure cortical activity during language processing, speech preparation, and speech execution in 25 participants with agenesis of the corpus callosum (AgCC) and 21 matched neurotypical individuals. In contrast to strongly lateralized left hemisphere activations for language in neurotypical controls, participants with complete or partial AgCC exhibited bilateral hemispheric activations in both auditory or visually driven language tasks, with complete AgCC participants showing significantly more right hemisphere activations than controls or than individuals with partial AgCC. In AgCC individuals, language laterality positively correlated with verbal IQ. These findings suggest that the corpus callosum helps to drive language lateralization. SIGNIFICANCE STATEMENT The role that corpus callosum development has on the hemispheric specialization of language is poorly understood. Here, we used magnetoencephalographic imaging during linguistic tests (verb generation, picture naming) to test for hemispheric dominance in patients with agenesis of the corpus callosum (AgCC) and found reduced laterality (i.e., greater likelihood of bilaterality or right hemisphere dominance) in this cohort compared with controls, especially in patients with complete agenesis. Laterality was positively correlated with behavioral measures of verbal intelligence. These findings provide support for the hypothesis that the callosum aids in functional specialization throughout neural development and that the loss of this mechanism

  5. Perspectives on Dichotic Listening and the Corpus Callosum

    ERIC Educational Resources Information Center

    Musiek, Frank E.; Weihing, Jeffrey

    2011-01-01

    The present review summarizes historic and recent research which has investigated the role of the corpus callosum in dichotic processing within the context of audiology. Examination of performance by certain clinical groups, including split brain patients, multiple sclerosis cases, and other types of neurological lesions is included. Maturational,…

  6. Corpus Callosum Anatomy in Chronically Treated and Stimulant Naive ADHD

    ERIC Educational Resources Information Center

    Schnoebelen, Sarah; Semrud-Clikeman, Margaret; Pliszka, Steven R.

    2010-01-01

    Objective: To determine the effect of chronic stimulant treatment on corpus callosum (CC) size in children with ADHD using volumetric and area measurements. Previously published research indicated possible medication effects on specific areas of the CC. Method: Measurements of the CC from anatomical MRIs were obtained from children aged 9-16 in…

  7. Agenesis of the corpus callosum. An autopsy study in fetuses.

    PubMed

    Kidron, Debora; Shapira, Daniel; Ben Sira, Liat; Malinger, Gustavo; Lev, Dorit; Cioca, Andreea; Sharony, Reuven; Lerman Sagie, Tally

    2016-02-01

    Agenesis of the corpus callosum is currently diagnosed prenatally with ultrasound and MRI. While the diagnostic aspects of callosal defects are widely addressed, anatomo-histological data from fetal autopsies are sparse. Callosal defects were present in 50 fetal autopsies. Four distinct groups of complete, partial, hypoplastic, and mixed defects were determined by the gross and histologic details of the corpus callosum. These details helped to rule out other midline defects such as holoprosencephaly. Additional autopsy findings enabled specific diagnoses and suggested etiopathogeneses. Hypoplastic and mixed defects were associated with more abnormalities of the cerebral hemispheres and internal organs. The four groups did not differ according to gender, external dysmorphism, or cerebellar and brainstem anomalies. Defects were classified as syndromic (68 %), encephaloclastic (8 %), undetermined (14 %), or isolated (10 %) based on the autopsy findings. Isolated agenesis of the corpus callosum was diagnosed in only 10 % of the cases in this series, compared to higher numbers diagnosed by prenatal ultrasonography and MRI. Therefore, the autopsy, through its detailed, careful evaluation of external, as well as gross and histological internal features, can elucidate the etiopathogenesis of agenesis of the corpus callosum and suggest specific diagnoses which cannot be ascertained by prenatal imaging.

  8. Corpus Callosum Differences Associated with Persistent Stuttering in Adults

    ERIC Educational Resources Information Center

    Choo, Ai Leen; Kraft, Shelly Jo; Olivero, William; Ambrose, Nicoline G.; Sharma, Harish; Chang, Soo-Eun; Loucks, Torrey M.

    2011-01-01

    Recent studies have implicated anatomical differences in speech-relevant brain regions of adults who stutter (AWS) compared to normally fluent adults (NFA). The present study focused on the region of the corpus callosum (CC) which is involved in interhemispheric processing between the left and right cerebral hemispheres. Two-dimensional…

  9. Autism Traits in Individuals with Agenesis of the Corpus Callosum

    ERIC Educational Resources Information Center

    Lau, Yolanda C.; Hinkley, Leighton B. N.; Bukshpun, Polina; Strominger, Zoe A.; Wakahiro, Mari L. J.; Baron-Cohen, Simon; Allison, Carrie; Auyeung, Bonnie; Jeremy, Rita J.; Nagarajan, Srikantan S.; Sherr, Elliott H.; Marco, Elysa J.

    2013-01-01

    Autism spectrum disorders (ASD) have numerous etiologies, including structural brain malformations such as agenesis of the corpus callosum (AgCC). We sought to directly measure the occurrence of autism traits in a cohort of individuals with AgCC and to investigate the neural underpinnings of this association. We screened a large AgCC cohort (n =…

  10. Parenting, corpus callosum, and executive function in preschool children.

    PubMed

    Kok, Rianne; Lucassen, Nicole; Bakermans-Kranenburg, Marian J; van IJzendoorn, Marinus H; Ghassabian, Akhgar; Roza, Sabine J; Govaert, Paul; Jaddoe, Vincent W; Hofman, Albert; Verhulst, Frank C; Tiemeier, Henning

    2014-01-01

    In this longitudinal population-based study (N = 544), we investigated whether early parenting and corpus callosum length predict child executive function abilities at 4 years of age. The length of the corpus callosum in infancy was measured using postnatal cranial ultrasounds at 6 weeks of age. At 3 years, two aspects of parenting were observed: maternal sensitivity during a teaching task and maternal discipline style during a discipline task. Parents rated executive function problems at 4 years of age in five domains of inhibition, shifting, emotional control, working memory, and planning/organizing, using the Behavior Rating Inventory of Executive Function-Preschool Version. Maternal sensitivity predicted less executive function problems at preschool age. A significant interaction was found between corpus callosum length in infancy and maternal use of positive discipline to determine child inhibition problems: The association between a relatively shorter corpus callosum in infancy and child inhibition problems was reduced in children who experienced more positive discipline. Our results point to the buffering potential of positive parenting for children with biological vulnerability.

  11. Commissurotomy of the Corpus Callosum and the Remedial Reader.

    ERIC Educational Resources Information Center

    Albert, Elaine

    Testimony presented at a congressional hearing on illiteracy (March 1986) indicated that good readers use their myelinated corpus callosum fibers (which connect the left and right hemispheres of the brain) at millisecond speeds to coordinate the two brain hemispheres. Students taught using the whole-word recognition method (also called the…

  12. Agenesis of the Corpus Callosum Due to Defective Glial Wedge Formation in Lhx2 Mutant Mice.

    PubMed

    Chinn, Gregory A; Hirokawa, Karla E; Chuang, Tony M; Urbina, Cecilia; Patel, Fenil; Fong, Jeanette; Funatsu, Nobuo; Monuki, Edwin S

    2015-09-01

    Establishment of the corpus callosum involves coordination between callosal projection neurons and multiple midline structures, including the glial wedge (GW) rostrally and hippocampal commissure caudally. GW defects have been associated with agenesis of the corpus callosum (ACC). Here we show that conditional Lhx2 inactivation in cortical radial glia using Emx1-Cre or Nestin-Cre drivers results in ACC. The ACC phenotype was characterized by aberrant ventrally projecting callosal axons rather than Probst bundles, and was 100% penetrant on 2 different mouse strain backgrounds. Lhx2 inactivation in postmitotic cortical neurons using Nex-Cre mice did not result in ACC, suggesting that the mutant phenotype was not autonomous to the callosal projection neurons. Instead, ACC was associated with an absent hippocampal commissure and a markedly reduced to absent GW. Expression studies demonstrated strong Lhx2 expression in the normal GW and in its radial glial progenitors, with absence of Lhx2 resulting in normal Emx1 and Sox2 expression, but premature exit from the cell cycle based on EdU-Ki67 double labeling. These studies define essential roles for Lhx2 in GW, hippocampal commissure, and corpus callosum formation, and suggest that defects in radial GW progenitors can give rise to ACC.

  13. Agenesis of the corpus callosum and autism: a comprehensive comparison

    PubMed Central

    Corsello, Christina; Kennedy, Daniel P.; Adolphs, Ralph

    2014-01-01

    The corpus callosum, with its ∼200 million axons, remains enigmatic in its contribution to cognition and behaviour. Agenesis of the corpus callosum is a congenital condition in which the corpus callosum fails to develop; such individuals exhibit localized deficits in non-literal language comprehension, humour, theory of mind and social reasoning. These findings together with parent reports suggest that behavioural and cognitive impairments in subjects with callosal agenesis may overlap with the profile of autism spectrum disorders, particularly with respect to impairments in social interaction and communication. To provide a comprehensive test of this hypothesis, we directly compared a group of 26 adults with callosal agenesis to a group of 28 adults with a diagnosis of autism spectrum disorder but no neurological abnormality. All participants had full-scale intelligence quotient scores >78 and groups were matched on age, handedness, and gender ratio. Using the Autism Diagnostic Observation Schedule together with current clinical presentation to assess autistic symptomatology, we found that 8/26 (about a third) of agenesis subjects presented with autism. However, more formal diagnosis additionally involving recollective parent-report measures regarding childhood behaviour showed that only 3/22 met complete formal criteria for an autism spectrum disorder (parent reports were unavailable for four subjects). We found no relationship between intelligence quotient and autism symptomatology in callosal agenesis, nor evidence that the presence of any residual corpus callosum differentiated those who exhibited current autism spectrum symptoms from those who did not. Relative to the autism spectrum comparison group, parent ratings of childhood behaviour indicated children with agenesis were less likely to meet diagnostic criteria for autism, even for those who met autism spectrum criteria as adults, and even though there was no group difference in parent report of current

  14. Agenesis of the corpus callosum and autism: a comprehensive comparison.

    PubMed

    Paul, Lynn K; Corsello, Christina; Kennedy, Daniel P; Adolphs, Ralph

    2014-06-01

    The corpus callosum, with its ∼200 million axons, remains enigmatic in its contribution to cognition and behaviour. Agenesis of the corpus callosum is a congenital condition in which the corpus callosum fails to develop; such individuals exhibit localized deficits in non-literal language comprehension, humour, theory of mind and social reasoning. These findings together with parent reports suggest that behavioural and cognitive impairments in subjects with callosal agenesis may overlap with the profile of autism spectrum disorders, particularly with respect to impairments in social interaction and communication. To provide a comprehensive test of this hypothesis, we directly compared a group of 26 adults with callosal agenesis to a group of 28 adults with a diagnosis of autism spectrum disorder but no neurological abnormality. All participants had full-scale intelligence quotient scores >78 and groups were matched on age, handedness, and gender ratio. Using the Autism Diagnostic Observation Schedule together with current clinical presentation to assess autistic symptomatology, we found that 8/26 (about a third) of agenesis subjects presented with autism. However, more formal diagnosis additionally involving recollective parent-report measures regarding childhood behaviour showed that only 3/22 met complete formal criteria for an autism spectrum disorder (parent reports were unavailable for four subjects). We found no relationship between intelligence quotient and autism symptomatology in callosal agenesis, nor evidence that the presence of any residual corpus callosum differentiated those who exhibited current autism spectrum symptoms from those who did not. Relative to the autism spectrum comparison group, parent ratings of childhood behaviour indicated children with agenesis were less likely to meet diagnostic criteria for autism, even for those who met autism spectrum criteria as adults, and even though there was no group difference in parent report of current

  15. Partial agenesis of corpus callosum--case study.

    PubMed

    Zamurović, M; Andjelic, S

    2014-01-01

    Agenesis of the corpus callosum is an uncommon cerebral malformation usually of unknown etiology. It can be associated with other brain abnormalities, such as ventriculomegaly, or in combination with problems with other organs, such as congenital heart defect, as well as with chromosome anomalies. Diagnosis of this rare anomaly is important not only because of possible association with other developmental anomalies but also because of postnatal treatment and evaluation of children with this disorder. This paper presents prenatal diagnosis of partial agenesis of the posterior part of corpus callosum of a fetus detected in gestational week 33 by ultrasonography as an isolated developmental disorder, i.e., not accompanied by other morphological anomalies of the fetus or chromosome aberrations or other genetic defects.

  16. Emotional Intelligence in Agenesis of the Corpus Callosum.

    PubMed

    Anderson, Luke B; Paul, Lynn K; Brown, Warren S

    2017-01-23

    People with agenesis of the corpus callosum (AgCC) with normal general intelligence have deficits in complex cognitive processing, as well as in social cognition. It is uncertain the extent to which impoverished processing of emotions may contribute to social processing deficiencies. We used the Mayer-Salovey-Caruso Emotional Intelligence Test to clarify the nature of emotional intelligence in 16 adults with AgCC. As hypothesized, persons with AgCC exhibited greater disparities from norms on tests involving more socially complex aspects of emotions. The AgCC group did not differ from norms on the Experiential subscale, but they were significantly below norms on the Strategic subscale. These findings suggest that the corpus callosum is not essential for experiencing and thinking about basic emotions in a "normal" way, but is necessary for more complex processes involving emotions in the context of social interactions.

  17. Prenatal PCB exposure, the corpus callosum, and response inhibition.

    PubMed Central

    Stewart, Paul; Fitzgerald, Susan; Reihman, Jacqueline; Gump, Brooks; Lonky, Edward; Darvill, Thomas; Pagano, Jim; Hauser, Peter

    2003-01-01

    The present study reports the association between prenatal exposure to polychlorinated biphenyls (PCBs), the corpus callosum, and response inhibition in children who are 4.5 years old. Children (n = 189) enrolled in the Oswego study were tested using a continuous performance test. We measured (square millimeters) the splenium of the corpus callosum, a pathway implicated in the regulation of response inhibition, using magnetic resonance imaging. Results indicated a dose-dependent association between cord blood PCBs and errors of commission. Splenium size but not other brain areas predicted errors of commission (r(2) = 0.20), with smaller size associated with more errors of commission. There was an interaction between splenium size and PCB exposure. The smaller the splenium, the larger the association between PCBs and errors of commission. If the association between PCBs and response inhibition is indeed causal, then children with suboptimal development of the splenium are particularly vulnerable to these effects. These data await replication. PMID:14527849

  18. Anterior commissure versus corpus callosum: A quantitative comparison across mammals.

    PubMed

    Ashwell, Ken W S

    2016-04-01

    Mammals rely on two major pathways to transfer information between the two hemispheres of the brain: the anterior commissure and the corpus callosum. Metatheria and monotremes rely exclusively on the anterior commissure for interhemispheric transfer between the isocortices and olfactory allocortices of each side, whereas Eutheria use a combination of the anterior commissure and an additional pathway exclusive to Eutheria, the corpus callosum. Midline cross-sectional area of the anterior commissure and corpus callosum were measured in a range of mammals from all three infraclasses and plotted against brain volume to determine how midline anterior commissure area and its size relative to the corpus callosum vary with brain size and taxon. In Metatheria, the square root of anterior commissure area rises in almost direct proportion with the cube root of brain volume (i.e. the ratio of the two is relatively constant), whereas among Eutheria the ratio of the square root of anterior commissure area to the cube root of brain volume declines slightly with increasing brain size. The total of isocortical and olfactory allocortical commissure area rises more rapidly with increasing brain volume among Eutheria than among Metatheria. This means that the midline isocortical and olfactory allocortical commissural area of metatherians with large brains (about 70 ml) is only about 50% of that among eutherians with similarly sized brains. On the other hand, isocortical and olfactory allocortical commissural area is similar in Metatheria and Eutheria at brain volumes around 1 ml. Among the Eutheria, some groups make less use of the anterior commissure pathway than do others: soricomorphs, rodents and cetaceans have smaller anterior commissures for their brain size than do afrosoricids, erinaceomorphs and proboscideans. The findings suggest that use of the anterior commissural route for isocortical commissural connections may have placed limitations on interhemispheric transfer of

  19. Anatomical-behavioral relationships: corpus callosum morphometry and hemispheric specialization.

    PubMed

    Clarke, J M; Zaidel, E

    1994-10-20

    We obtained midsagittal measures of the corpus callosum in 60 healthy young adults (right-handed and left-handed males and females), and examined whether individual differences in anatomical measures of callosal connectivity are related to behavioral laterality measures in the same subjects. In an attempt to tap functionally-distinct callosal "channels", four behavioral laterality tasks were used that differed in sensory modality (visual, auditory, tactile) and/or level of cognitive processing (sensory versus semantic). In addition, the tasks had both intrahemispheric and interhemispheric conditions. Sex differences were found for measures of the posterior body (i.e. isthmus) of the corpus callosum, which, in turn, interacted with handedness. In contrast, only handedness effects were found for the behavioral laterality measures. Anatomical-behavioral correlations did not disclose relationships between callosal size and performance on task conditions requiring sensory interhemispheric integration or transfer. Instead, the correlational findings are consistent with the view that the corpus callosum participates in such higher order "control" functions as the support of bilateral representation of language, functional interhemispheric inhibition, and the maintenance of hemispheric differences in arousal. This is consistent with the finding that regional callosal size is related to the number of small diameter fibers, which are presumed to interconnect homologous association cortices in the two hemispheres.

  20. Lesions of the corpus callosum and other commissural fibers: diffusion tensor studies.

    PubMed

    Filippi, Christopher G; Cauley, Keith A

    2014-10-01

    The corpus callosum is the largest white matter tract in the brain, connecting the 2 hemispheres. The functions of the corpus callosum are many and varied, and lesions frequently cause only subtle clinical findings. The range of diseases that can affect the corpus callosum is vast and includes all potential white matter disease. The distribution of lesions in the corpus callosum is disease specific in only a few entities such as Susac syndrome and Marchiafava-Bignami disease. Group studies have found significant differences of diffusivity metrics in the corpus callosum in preterm infants, patients suffering seizure activity, and patients with early-onset Alzheimer's disease. Given the challenges that multiple orientation of fibers within the callosum presents, advanced postprocessing methods may be required to reveal ultrastructural disease.

  1. Facial emotion recognition in agenesis of the corpus callosum

    PubMed Central

    2014-01-01

    Background Impaired social functioning is a common symptom of individuals with developmental disruptions in callosal connectivity. Among these developmental conditions, agenesis of the corpus callosum provides the most extreme and clearly identifiable example of callosal disconnection. To date, deficits in nonliteral language comprehension, humor, theory of mind, and social reasoning have been documented in agenesis of the corpus callosum. Here, we examined a basic social ability as yet not investigated in this population: recognition of facial emotion and its association with social gaze. Methods Nine individuals with callosal agenesis and nine matched controls completed four tasks involving emotional faces: emotion recognition from upright and inverted faces, gender recognition, and passive viewing. Eye-tracking data were collected concurrently on all four tasks and analyzed according to designated facial regions of interest. Results Individuals with callosal agenesis exhibited impairments in recognizing emotions from upright faces, in particular lower accuracy for fear and anger, and these impairments were directly associated with diminished attention to the eye region. The callosal agenesis group exhibited greater consistency in emotion recognition across conditions (upright vs. inverted), with poorest performance for fear identification in both conditions. The callosal agenesis group also had atypical facial scanning (lower fractional dwell time in the eye region) during gender naming and passive viewing of faces, but they did not differ from controls on gender naming performance. The pattern of results did not differ when taking into account full-scale intelligence quotient or presence of autism spectrum symptoms. Conclusions Agenesis of the corpus callosum results in a pattern of atypical facial scanning characterized by diminished attention to the eyes. This pattern suggests that reduced callosal connectivity may contribute to the development and

  2. Corpus callosum thickness in children: an MR pattern-recognition approach on the midsagittal image.

    PubMed

    Andronikou, Savvas; Pillay, Tanyia; Gabuza, Lungile; Mahomed, Nasreen; Naidoo, Jaishree; Hlabangana, Linda Tebogo; du Plessis, Vicci; Prabhu, Sanjay P

    2015-02-01

    Thickening of the corpus callosum is an important feature of development, whereas thinning of the corpus callosum can be the result of a number of diseases that affect development or cause destruction of the corpus callosum. Corpus callosum thickness reflects the volume of the hemispheres and responds to changes through direct effects or through Wallerian degeneration. It is therefore not only important to evaluate the morphology of the corpus callosum for congenital anomalies but also to evaluate the thickness of specific components or the whole corpus callosum in association with other findings. The goal of this pictorial review is raise awareness that the thickness of the corpus callosum can be a useful feature of pathology in pediatric central nervous system disease and must be considered in the context of the stage of development of a child. Thinning of the corpus callosum can be primary or secondary, and generalized or focal. Primary thinning is caused by abnormal or failed myelination related to the hypomyelinating leukoencephalopathies, metabolic disorders affecting white matter, and microcephaly. Secondary thinning of the corpus callosum can be caused by diffuse injury such as hypoxic-ischemic encephalopathy, human immunodeficiency virus (HIV) encephalopathy, hydrocephalus, dysmyelinating conditions and demyelinating conditions. Focal disturbance of formation or focal injury also causes localized thinning, e.g., callosal dysgenesis, metabolic disorders with localized effects, hypoglycemia, white matter injury of prematurity, HIV-related atrophy, infarction and vasculitis, trauma and toxins. The corpus callosum might be too thick because of a primary disorder in which the corpus callosum finding is essential to diagnosis; abnormal thickening can also be secondary to inflammation, infection and trauma.

  3. A computerized approach for morphological analysis of the corpus callosum

    SciTech Connect

    Davatzikos, C.; Vaillant, M.; Letovsky, S.; Bryan, R.N.; Prince, J.L.; Resnick, S.M.

    1996-01-01

    A new technique for analyzing the morphology of the corpus callosum is presented, and it is applied to a group of elderly subjects. The proposed approach normalizes subject data into the Talairach space using an elastic deformation transformation. The properties of this transformation are used as a quantitative description of the callosal shape with respect to the Talairach atlas, which is treated as a standard. In particular, a deformation function measures the enlargement/shrinkage associated with this elastic deformation. Intersubject comparisons are made by comparing deformation functions. This technique was applied to eight male and eight female subjects. Based on the average deformation functions of each group, the posterior region of the female corpus callosum was found to be larger than its corresponding region in the males. The average callosal shape of each group was also found, demonstrating visually the callosal shape differences between the two groups in this sample. The proposed methodology utilizes the full resolution of the data, rather than relying on global descriptions such as area measurements. The application of this methodology to an elderly group indicated sex-related differences in the callosal shape and size. 29 refs., 16 figs.

  4. Organising white matter in a brain without corpus callosum fibres.

    PubMed

    Bénézit, Audrey; Hertz-Pannier, Lucie; Dehaene-Lambertz, Ghislaine; Monzalvo, Karla; Germanaud, David; Duclap, Delphine; Guevara, Pamela; Mangin, Jean-François; Poupon, Cyril; Moutard, Marie-Laure; Dubois, Jessica

    2015-02-01

    Isolated corpus callosum dysgenesis (CCD) is a congenital malformation which occurs during early development of the brain. In this study, we aimed to identify and describe its consequences beyond the lack of callosal fibres, on the morphology, microstructure and asymmetries of the main white matter bundles with diffusion imaging and fibre tractography. Seven children aged between 9 and 13 years old and seven age- and gender-matched control children were studied. First, we focused on bundles within the mesial region of the cerebral hemispheres: the corpus callosum, Probst bundles and cingulum which were selected using a conventional region-based approach. We demonstrated that the Probst bundles have a wider connectivity than the previously described rostrocaudal direction, and a microstructure rather distinct from the cingulum but relatively close to callosal remnant fibres. A sigmoid bundle was found in two partial ageneses. Second, the corticospinal tract, thalamic radiations and association bundles were extracted automatically via an atlas of adult white matter bundles to overcome bias resulting from a priori knowledge of the bundles' anatomical morphology and trajectory. Despite the lack of callosal fibres and the colpocephaly observed in CCD, all major white matter bundles were identified with a relatively normal morphology, and preserved microstructure (i.e. fractional anisotropy, mean diffusivity) and asymmetries. Consequently the bundles' organisation seems well conserved in brains with CCD. These results await further investigations with functional imaging before apprehending the cognition variability in children with isolated dysgenesis.

  5. Verbal learning and memory in agenesis of the corpus callosum

    PubMed Central

    Erickson, Roger L.; Paul, Lynn K.; Brown, Warren S.

    2015-01-01

    The role of interhemispheric interactions in the encoding, retention, and retrieval of verbal memory can be clarified by assessing individuals with complete or partial agenesis of the corpus callosum (AgCC), but who have normal intelligence. This study assessed verbal learning and memory in AgCC using the California Verbal Learning Test—Second Edition (CVLT-II). Twenty-six individuals with AgCC were compared to 24 matched controls on CVLT-II measures, as well as Donders’ four CVLT-II factors (i.e., Attention Span, Learning Efficiency, Delayed Memory, and Inaccurate Memory). Individuals with AgCC performed significantly below healthy controls on the Delayed Memory factor, confirmed by significant deficits in short and long delayed free recall and cued recall. They also performed less well in original learning. Deficient performance by individuals with AgCC during learning trials, as well as deficits in all forms of delayed memory, suggest that the corpus callosum facilitates interhemispheric elaboration and encoding of verbal information. PMID:24933663

  6. Corpus Callosum and Prefrontal Functions in Adolescents with History of Very Preterm Birth

    ERIC Educational Resources Information Center

    Narberhaus, Ana; Segarra, Dolors; Caldu, Xavier; Gimenez, Monica; Pueyo, Roser; Botet, Francesc; Junque, Carme

    2008-01-01

    Very preterm (VPT) birth can account for thinning of the corpus callosum and poorer cognitive performance. Research findings about preterm and VPT adolescents usually describe a small posterior corpus callosum, although our research group has also found reductions of the anterior part, specifically the genu. The aim of the present study was to…

  7. Automated segmentation of the corpus callosum in midsagittal brain magnetic resonance images

    NASA Astrophysics Data System (ADS)

    Lee, Chulhee; Huh, Shin; Ketter, Terence A.; Unser, Michael A.

    2000-04-01

    We propose a new algorithm to find the corpus callosum automatically from midsagittal brain MR (magnetic resonance) images using the statistical characteristics and shape information of the corpus callosum. We first extract regions satisfying the statistical characteristics (gray level distributions) of the corpus callosum that have relatively high intensity values. Then we try to find a region matching the shape information of the corpus callosum. In order to match the shape information, we propose a new directed window region growing algorithm instead of using conventional contour matching. An innovative feature of the algorithm is that we adaptively relax the statistical requirement until we find a region matching the shape information. After the initial segmentation, a directed border path pruning algorithm is proposed in order to remove some undesired artifacts, especially on the top of the corpus callosum. The proposed algorithm was applied to over 120 images and provided promising results.

  8. Effects of citicoline therapy on the network connectivity of the corpus callosum in patients with leukoaraiosis

    PubMed Central

    Feng, Liang; Jiang, Hong; Li, Yunxia; Teng, Fei; He, Yusheng

    2017-01-01

    Abstract This study aimed to investigate the effects of citicoline therapy on the network connectivity of the corpus callosum in patients with leukoaraiosis (LA) by diffusion tension imaging (DTI). A total of 30 LA patients with Fazekas score of 2 to 3 were voluntarily assigned into citicoline group (n = 14) and control group (n = 16). In citicoline group, citicoline was administered at 0.6 g/d for 1 year. In control group, central nervous system drugs should not be used, except for sleeping pills and antidepressants. Interventions for pre-existing diseases should be conducted in both groups. During the periods of citicoline therapy and post-treatment follow-up, cranial magnetic resonance imaging and DTI were routinely performed in these patients, and the genu, body, and splenium of corpus callosum were selected as the regions of interest (ROIs). The fractional anisotropy (FA) and mean diffusivity (MD) of each ROI were determined with PANDA software. On recruitment, there were no significant differences in the general characteristics, blood biochemical results, cognition function, and the FA and MD of the corpus callosum between 2 groups (P > 0.05). After 1-year treatment, the FA of the corpus callosum reduced gradually, but the MD of the corpus callosum tended to increased in both group, although significant differences were not observed. However, the reductions in FA of genu and splenium of corpus callosum in citicoline group were significantly lower than in control group (P < 0.05); the reductions in MD of genu, body, and splenium of corpus callosum in citicoline group were significantly lower than in control group (P < 0.05). In LA patients, the disruption of the network connectivity of the corpus callosum deteriorates over time. Citicoline treatment may delay the reduction in FA of corpus callosum, which might be beneficial for the improvement of network connectivity of the corpus callosum. PMID:28121935

  9. Effects of citicoline therapy on the network connectivity of the corpus callosum in patients with leukoaraiosis.

    PubMed

    Feng, Liang; Jiang, Hong; Li, Yunxia; Teng, Fei; He, Yusheng

    2017-01-01

    This study aimed to investigate the effects of citicoline therapy on the network connectivity of the corpus callosum in patients with leukoaraiosis (LA) by diffusion tension imaging (DTI).A total of 30 LA patients with Fazekas score of 2 to 3 were voluntarily assigned into citicoline group (n = 14) and control group (n = 16). In citicoline group, citicoline was administered at 0.6 g/d for 1 year. In control group, central nervous system drugs should not be used, except for sleeping pills and antidepressants. Interventions for pre-existing diseases should be conducted in both groups. During the periods of citicoline therapy and post-treatment follow-up, cranial magnetic resonance imaging and DTI were routinely performed in these patients, and the genu, body, and splenium of corpus callosum were selected as the regions of interest (ROIs). The fractional anisotropy (FA) and mean diffusivity (MD) of each ROI were determined with PANDA software.On recruitment, there were no significant differences in the general characteristics, blood biochemical results, cognition function, and the FA and MD of the corpus callosum between 2 groups (P > 0.05). After 1-year treatment, the FA of the corpus callosum reduced gradually, but the MD of the corpus callosum tended to increased in both group, although significant differences were not observed. However, the reductions in FA of genu and splenium of corpus callosum in citicoline group were significantly lower than in control group (P < 0.05); the reductions in MD of genu, body, and splenium of corpus callosum in citicoline group were significantly lower than in control group (P < 0.05).In LA patients, the disruption of the network connectivity of the corpus callosum deteriorates over time. Citicoline treatment may delay the reduction in FA of corpus callosum, which might be beneficial for the improvement of network connectivity of the corpus callosum.

  10. The subventricular zone continues to generate corpus callosum and rostral migratory stream astroglia in normal adult mice.

    PubMed

    Sohn, Jiho; Orosco, Lori; Guo, Fuzheng; Chung, Seung-Hyuk; Bannerman, Peter; Mills Ko, Emily; Zarbalis, Kostas; Deng, Wenbin; Pleasure, David

    2015-03-04

    Astrocytes are the most abundant cells in the CNS, and have many essential functions, including maintenance of blood-brain barrier integrity, and CNS water, ion, and glutamate homeostasis. Mammalian astrogliogenesis has generally been considered to be completed soon after birth, and to be reactivated in later life only under pathological circumstances. Here, by using genetic fate-mapping, we demonstrate that new corpus callosum astrocytes are continuously generated from nestin(+) subventricular zone (SVZ) neural progenitor cells (NPCs) in normal adult mice. These nestin fate-mapped corpus callosum astrocytes are uniformly postmitotic, express glutamate receptors, and form aquaporin-4(+) perivascular endfeet. The entry of new astrocytes from the SVZ into the corpus callosum appears to be balanced by astroglial apoptosis, because overall numbers of corpus callosum astrocytes remain constant during normal adulthood. Nestin fate-mapped astrocytes also flow anteriorly from the SVZ in association with the rostral migratory stream, but do not penetrate into the deeper layers of the olfactory bulb. Production of new astrocytes from nestin(+) NPCs is absent in the normal adult cortex, striatum, and spinal cord. Our study is the first to demonstrate ongoing SVZ astrogliogenesis in the normal adult mammalian forebrain.

  11. Ultrasound measurement of the corpus callosum and neural development of premature infants.

    PubMed

    Liu, Fang; Cao, Shikao; Liu, Jiaoran; Du, Zhifang; Guo, Zhimei; Ren, Changjun

    2013-09-15

    Length and thickness of 152 corpus callosa were measured in neonates within 24 hours of birth. Using ultrasonic diagnostic equipment with a neonatal brain-specific probe, corpus callosum length and thickness of the genu, body, and splenium were measured on the standard mid-sagittal plane, and the anteroposterior diameter of the genu was measured in the coronal plane. Results showed that corpus callosum length as well as thickness of the genu and splenium increased with tional age and birth weight, while other measures did not. These three factors on the standard mid-sagittal plane are therefore likely to be suitable for real-time evaluation of corpus callosum velopment in premature infants using cranial ultrasound. Further analysis revealed that thickness of the body and splenium and the anteroposterior diameter of the genu were greater in male infants than in female infants, suggesting that there are sex differences in corpus callosum size during the neonatal period. A second set of measurements were taken from 40 premature infants whose gestational age was 34 weeks or less. Corpus callosum measurements were corrected to a gestational age of 40 weeks, and infants were grouped for analysis depending on the outcome of a neonatal behavioral neurological assessment. Compared with infants with a normal neurological assessment, corpus callosum length and genu and splenium thicknesses were less in those with abnormalities, indicating that corpus callosum growth in premature infants is associated with neurobehavioral development during the early extrauterine stage.

  12. Agenesis of the Corpus Callosum in Two Sisters

    PubMed Central

    Shapira, Yehuda; Cohen, Tirza

    1973-01-01

    Two sisters are described. They are offspring of Arabic parents who are both first and second cousins, through both sets of grandparents; additionally the father's parents are first cousins. The diagnosis of agenesis of the corpus callosum in the propositae was made by the characteristic picture on the pneumoencephalogram. The clinical symptoms in the two sisters varied considerably. The older sister had shown delayed psychomotor development in infancy, mild mental retardation, and developed seizures at 7 years of age of both the grand mal and akinetic types. Her physical and neurological examination did not show any abnormalities. The EEG was severely abnormal with slow wave activity over the posterior parts of the brain and focal spiking. The younger sister presented at 6 months of age with failure to thrive, generalized hypotonia, but without seizures. Her EEG was within normal limits. This anomaly was probably transmitted by an autosomal recessive gene. The clinical and genetic aspects of this syndrome are discussed. Images PMID:4204338

  13. Clinical features of acute corpus callosum infarction patients

    PubMed Central

    Yang, Li-Li; Huang, Yi-Ning; Cui, Zhi-Tang

    2014-01-01

    The clinical manifestation of acute corpus callosum (CC) infarction is lack of specificity and complex, so it is easily missed diagnosis and misdiagnosis in the early stage. The present study aims to describe the clinical features of the acute CC infarction. In this study, 25 patients with corpus callosum infarction confirmed by the brain MRI/DWI and the risk factors were summarized. Patients were classified into genu infarction (3 cases), body infarction (4cases), body and genu infarction (4 cases), body and splenium infarction (1 case), splenium infarction (13 cases) according to lesion location. Clinical manifestation and prognosis were analyzed among groups. The results indicated that CC infarction in patients with high-risk group accounted for 72%, moderate-risk group accounted for 20%, low-risk group (8%). The main risk factors are carotid intimal thickening or plaque formation, hypertension, hyperlipidemia, cerebral artery stenosis, and so on. The CC infarction often merged with other parts infarction, and splenium infarction had the highest incidence, the clinical symptoms in the body infarction which can appear typical signs and symptoms, but in other parts infarction which always merged many nerve defect symptoms. The body infarction prognosis is poor; the rest parts of infarction are more favorable prognosis. In conclusion, CC infarction has the highest incidence in the stroke of high-risk group; neck color Doppler and TCD examination can be found as early as possible to explore the pathogenic factors. Prognosis is usually much better by treatment according to the location and risk factors. PMID:25197390

  14. Morphologic alterations in the corpus callosum in abuse-related posttraumatic stress disorder: a preliminary study.

    PubMed

    Kitayama, Noriyuki; Brummer, Marijn; Hertz, Lois; Quinn, Sinead; Kim, Yoshiharu; Bremner, J Douglas

    2007-12-01

    Magnetic resonance imaging (MRI) studies in children with maltreatment-related posttraumatic stress disorder (PTSD) have demonstrated smaller corpus callosum area, with the greatest magnitude of change in posterior portions of the corpus callosum. The purpose of this study was to measure corpus callosum area in adult female patients with childhood abuse-related PTSD and comparison subjects. MRI was used to measure the midsagittal area of the corpus callosum as well as subregions of the corpus callosum in 9 female subjects with abuse-related PTSD and 9 healthy female subjects. No differences were found in total area of the corpus callosum or in individual subregions, but the subregion/total area ratio was significantly smaller in posterior midbody in PTSD compared with the healthy subjects. These results suggest that relatively smaller areas of the posterior midbody of the corpus callosum are associated with childhood abuse related PTSD in adults; these findings are consistent with findings in children with abuse-related PTSD.

  15. Magnetic resonance findings of the corpus callosum in canine and feline lysosomal storage diseases.

    PubMed

    Hasegawa, Daisuke; Tamura, Shinji; Nakamoto, Yuya; Matsuki, Naoaki; Takahashi, Kimimasa; Fujita, Michio; Uchida, Kazuyuki; Yamato, Osamu

    2013-01-01

    Several reports have described magnetic resonance (MR) findings in canine and feline lysosomal storage diseases such as gangliosidoses and neuronal ceroid lipofuscinosis. Although most of those studies described the signal intensities of white matter in the cerebrum, findings of the corpus callosum were not described in detail. A retrospective study was conducted on MR findings of the corpus callosum as well as the rostral commissure and the fornix in 18 cases of canine and feline lysosomal storage diseases. This included 6 Shiba Inu dogs and 2 domestic shorthair cats with GM1 gangliosidosis; 2 domestic shorthair cats, 2 familial toy poodles, and a golden retriever with GM2 gangliosidosis; and 2 border collies and 3 chihuahuas with neuronal ceroid lipofuscinoses, to determine whether changes of the corpus callosum is an imaging indicator of those diseases. The corpus callosum and the rostral commissure were difficult to recognize in all cases of juvenile-onset gangliosidoses (GM1 gangliosidosis in Shiba Inu dogs and domestic shorthair cats and GM2 gangliosidosis in domestic shorthair cats) and GM2 gangliosidosis in toy poodles with late juvenile-onset. In contrast, the corpus callosum and the rostral commissure were confirmed in cases of GM2 gangliosidosis in a golden retriever and canine neuronal ceroid lipofuscinoses with late juvenile- to early adult-onset, but were extremely thin. Abnormal findings of the corpus callosum on midline sagittal images may be a useful imaging indicator for suspecting lysosomal storage diseases, especially hypoplasia (underdevelopment) of the corpus callosum in juvenile-onset gangliosidoses.

  16. Corpus callosum shape is altered in individuals with nonsyndromic cleft lip and palate.

    PubMed

    Weinberg, Seth M; Parsons, Trish E; Fogel, Melissa R; Walter, Courtney P; Conrad, Amy L; Nopoulos, Peg

    2013-05-01

    Individuals with nonsyndromic cleft lip with or without cleft palate (CL/P) have altered brain structure compared with healthy controls. Preliminary evidence suggests that the corpus callosum may be dysmorphic in orofacial clefting; however, this midline brain structure has not been systematically assessed in this population. The goal of the present study was to carry out a morphometric assessment of the corpus callosum and its relationship to cognitive performance in a well-characterized patient cohort with orofacial cleft. Midline brain images were obtained from previously collected MRI scans of 24 CL/P subjects and 40-adult-male controls. Eight landmarks on the corpus callosum were digitized on each image and their x,y coordinate locations saved. A geometric morphometrics analysis was applied to the landmark coordinate data to test for shape differences across groups. The relationship between corpus callosum shape and IQ was explored with nonparametric correlation coefficients. Results revealed significant differences in mean corpus callosum shape between CL/P cases and controls (P = 0.029). The CL/P corpus callosum was characterized by increased overall convexity resulting from a superior and posterior displacement. Within CL/P cases, increased corpus callosum shape dysmorphology was moderately correlated with reduced performance IQ (r = 0.546). These results provide additional evidence that midline brain changes may be an important part of the orofacial cleft phenotype.

  17. Clinics in diagnostic imaging (175). Corpus callosum glioblastoma multiforme (GBM): butterfly glioma.

    PubMed

    Krishnan, Vijay; Lim, Tze Chwan; Ho, Francis Cho Hao; Peh, Wilfred Cg

    2017-03-01

    A 54-year-old man presented with change in behaviour, nocturnal enuresis, abnormal limb movement and headache of one week's duration. The diagnosis of butterfly glioma (glioblastoma multiforme) was made based on imaging characteristics and was further confirmed by biopsy findings. As the corpus callosum is usually resistant to infiltration by tumours, a mass that involves and crosses the corpus callosum is suggestive of an aggressive neoplasm. Other neoplastic and non-neoplastic conditions that may involve the corpus callosum and mimic a butterfly glioma, as well as associated imaging features, are discussed.

  18. Cross-sectional area of the elephant corpus callosum: comparison to other eutherian mammals.

    PubMed

    Manger, P R; Hemingway, J; Haagensen, M; Gilissen, E

    2010-05-19

    The current study reports our findings of the relationship between cross-sectional area of the corpus callosum and brain mass in over 100 eutherian mammal species. We were specifically interested in determining whether the elephant had a corpus callosum the size that would be expected for eutherian mammal with a brain mass of approximately 5000 g, or whether a different morphology had evolved. To answer this question we first analysed data from primates, other eutherian mammals and cetaceans, finding that primates and other eutherian mammals showed a positive allometric relationship between the two variables, such that larger brains had a relatively larger corpus callosum. Interestingly, primates have a slightly larger corpus callosum than other eutherian mammals, but showed a similar allometric scaling to this group. The cetaceans had a both absolutely and relatively small corpus callosum compared to other mammals and showed isometric scaling with brain mass. The six elephants studied herein had the largest absolute corpus callosums recorded to date; however, relative to the mass of their brain, the size of the corpus callosum was what would be expected of a typical eutherian mammal with a brain mass of approximately 5000 g. The data for elephants hinted at sexual dimorphism in size of the corpus callosum, with female elephants having both an absolute and relatively larger callosum than the males. If this observation is supported in future studies, the elephants will be the first non-primate species to show sexual dimorphism in this neural character. The results are discussed in both an evolutionary and functional context.

  19. Mutations in DCC cause isolated agenesis of the corpus callosum with incomplete penetrance.

    PubMed

    Marsh, Ashley P L; Heron, Delphine; Edwards, Timothy J; Quartier, Angélique; Galea, Charles; Nava, Caroline; Rastetter, Agnès; Moutard, Marie-Laure; Anderson, Vicki; Bitoun, Pierre; Bunt, Jens; Faudet, Anne; Garel, Catherine; Gillies, Greta; Gobius, Ilan; Guegan, Justine; Heide, Solveig; Keren, Boris; Lesne, Fabien; Lukic, Vesna; Mandelstam, Simone A; McGillivray, George; McIlroy, Alissandra; Méneret, Aurélie; Mignot, Cyril; Morcom, Laura R; Odent, Sylvie; Paolino, Annalisa; Pope, Kate; Riant, Florence; Robinson, Gail A; Spencer-Smith, Megan; Srour, Myriam; Stephenson, Sarah E M; Tankard, Rick; Trouillard, Oriane; Welniarz, Quentin; Wood, Amanda; Brice, Alexis; Rouleau, Guy; Attié-Bitach, Tania; Delatycki, Martin B; Mandel, Jean-Louis; Amor, David J; Roze, Emmanuel; Piton, Amélie; Bahlo, Melanie; Billette de Villemeur, Thierry; Sherr, Elliott H; Leventer, Richard J; Richards, Linda J; Lockhart, Paul J; Depienne, Christel

    2017-04-01

    Brain malformations involving the corpus callosum are common in children with developmental disabilities. We identified DCC mutations in four families and five sporadic individuals with isolated agenesis of the corpus callosum (ACC) without intellectual disability. DCC mutations result in variable dominant phenotypes with decreased penetrance, including mirror movements and ACC associated with a favorable developmental prognosis. Possible phenotypic modifiers include the type and location of mutation and the sex of the individual.

  20. Restricted diffusion in the corpus callosum: A neuroradiological marker in hypoxic–ischemic encephalopathy

    PubMed Central

    Kale, Alok; Joshi, Priscilla; Kelkar, A B

    2016-01-01

    Background: Restricted diffusion within the splenium of the corpus callosum has been described by other authors in various conditions, however, restricted diffusion in the entire corpus callosum or isolated involvement of the splenium, genu, or body has been infrequently reported on magnetic resonance imaging (MRI) in neonatal hypoxic–ischemic encephalopathy. We report a series of cases showing different patterns of involvement. Methods and Materials: Perinatal imaging with MRI including diffusion-weighted imaging was performed in 40 neonates with hypoxic–ischemic encephalopathy, including 11 premature neonates. Sixteen out of 40 patients demonstrated restricted diffusion within the corpus callosum. Out of 16 patients, 9 showed restricted diffusion in the entire corpus callosum, 4 had isolated splenium involvement, 2 had body and splenium signal abnormality, and 1 showed diffusion restriction only in the genu. Conclusions: Changes in the corpus callosum were also associated with more severe clinical presentation of encephalopathy. Restricted diffusion within the corpus callosum in infants with hypoxic–ischemic encephalopathy is often associated with extensive brain injury and appears to be an early neuroradiologic marker of adverse neurologic outcome. PMID:28104944

  1. Segmentation of corpus callosum using diffusion tensor imaging: validation in patients with glioblastoma

    PubMed Central

    2012-01-01

    Background This paper presents a three-dimensional (3D) method for segmenting corpus callosum in normal subjects and brain cancer patients with glioblastoma. Methods Nineteen patients with histologically confirmed treatment naïve glioblastoma and eleven normal control subjects underwent DTI on a 3T scanner. Based on the information inherent in diffusion tensors, a similarity measure was proposed and used in the proposed algorithm. In this algorithm, diffusion pattern of corpus callosum was used as prior information. Subsequently, corpus callosum was automatically divided into Witelson subdivisions. We simulated the potential rotation of corpus callosum under tumor pressure and studied the reproducibility of the proposed segmentation method in such cases. Results Dice coefficients, estimated to compare automatic and manual segmentation results for Witelson subdivisions, ranged from 94% to 98% for control subjects and from 81% to 95% for tumor patients, illustrating closeness of automatic and manual segmentations. Studying the effect of corpus callosum rotation by different Euler angles showed that although segmentation results were more sensitive to azimuth and elevation than skew, rotations caused by brain tumors do not have major effects on the segmentation results. Conclusions The proposed method and similarity measure segment corpus callosum by propagating a hyper-surface inside the structure (resulting in high sensitivity), without penetrating into neighboring fiber bundles (resulting in high specificity). PMID:22591335

  2. Oligodendrocyte lineage and subventricular zone response to traumatic axonal injury in the corpus callosum.

    PubMed

    Sullivan, Genevieve M; Mierzwa, Amanda J; Kijpaisalratana, Naruchorn; Tang, Haiying; Wang, Yong; Song, Sheng-Kwei; Selwyn, Reed; Armstrong, Regina C

    2013-12-01

    Traumatic brain injury frequently causes traumatic axonal injury (TAI) in white matter tracts. Experimental TAI in the corpus callosum of adult mice was used to examine the effects on oligodendrocyte lineage cells and myelin in conjunction with neuroimaging. The injury targeted the corpus callosum over the subventricular zone, a source of neural stem/progenitor cells. Traumatic axonal injury was produced in the rostral body of the corpus callosum by impact onto the skull at the bregma. During the first week after injury, magnetic resonance diffusion tensor imaging showed that axial diffusivity decreased in the corpus callosum and that corresponding regions exhibited significant axon damage accompanied by hypertrophic microglia and reactive astrocytes. Oligodendrocyte progenitor proliferation increased in the subventricular zone and corpus callosum. Oligodendrocytes in the corpus callosum shifted toward upregulation of myelin gene transcription. Plp/CreER(T):R26IAP reporter mice showed normal reporter labeling of myelin sheaths 0 to 2 days after injury but labeling was increased between 2 and 7 days after injury. Electron microscopy revealed axon degeneration, demyelination, and redundant myelin figures. These findings expand the cell types and responses to white matter injuries that inform diffusion tensor imaging evaluation and identify pivotal white matter changes after TAI that may affect axon vulnerability vs. recovery after brain injury.

  3. Tractography of the Corpus Callosum in Huntington’s Disease

    PubMed Central

    Phillips, Owen; Sanchez-Castaneda, Cristina; Elifani, Francesca; Maglione, Vittorio; Di Pardo, Alba; Caltagirone, Carlo; Squitieri, Ferdinando; Sabatini, Umberto; Di Paola, Margherita

    2013-01-01

    White matter abnormalities have been shown in presymptomatic and symptomatic Huntington’s disease (HD) subjects using Magnetic Resonance Imaging (MRI) and Diffusion Tensor Imaging (DTI) methods. The largest white matter tract, the corpus callosum (CC), has been shown to be particularly vulnerable; however, little work has been done to investigate the regional specificity of tract abnormalities in the CC. Thus, this study examined the major callosal tracts by applying DTI-based tractography. Using TrackVis, a previously defined region of interest tractography method parcellating CC into seven major tracts based on target region was applied to 30 direction DTI data collected from 100 subjects: presymptomatic HD (Pre-HD) subjects (n = 25), HD patients (n = 25) and healthy control subjects (n = 50). Tractography results showed decreased fractional anisotropy (FA) and increased radial diffusivity (RD) across broad regions of the CC in Pre-HD subjects. Similar though more severe deficits were seen in HD patients. In Pre-HD and HD, callosal FA and RD were correlated with Disease Burden/CAG repeat length as well as motor (UHDRSI) and cognitive (URDRS2) assessments. These results add evidence that CC pathways are compromised prior to disease onset with possible demyelination occurring early in the disease and suggest that CAG repeat length is a contributing factor to connectivity deficits. Furthermore, disruption of these callosal pathways potentially contributes to the disturbances of motor and cognitive processing that characterize HD. PMID:24019913

  4. Parametric Probability Distribution Functions for Axon Diameters of Corpus Callosum.

    PubMed

    Sepehrband, Farshid; Alexander, Daniel C; Clark, Kristi A; Kurniawan, Nyoman D; Yang, Zhengyi; Reutens, David C

    2016-01-01

    Axon diameter is an important neuroanatomical characteristic of the nervous system that alters in the course of neurological disorders such as multiple sclerosis. Axon diameters vary, even within a fiber bundle, and are not normally distributed. An accurate distribution function is therefore beneficial, either to describe axon diameters that are obtained from a direct measurement technique (e.g., microscopy), or to infer them indirectly (e.g., using diffusion-weighted MRI). The gamma distribution is a common choice for this purpose (particularly for the inferential approach) because it resembles the distribution profile of measured axon diameters which has been consistently shown to be non-negative and right-skewed. In this study we compared a wide range of parametric probability distribution functions against empirical data obtained from electron microscopy images. We observed that the gamma distribution fails to accurately describe the main characteristics of the axon diameter distribution, such as location and scale of the mode and the profile of distribution tails. We also found that the generalized extreme value distribution consistently fitted the measured distribution better than other distribution functions. This suggests that there may be distinct subpopulations of axons in the corpus callosum, each with their own distribution profiles. In addition, we observed that several other distributions outperformed the gamma distribution, yet had the same number of unknown parameters; these were the inverse Gaussian, log normal, log logistic and Birnbaum-Saunders distributions.

  5. Viscoelasticity of brain corpus callosum in biaxial tension

    NASA Astrophysics Data System (ADS)

    Labus, Kevin M.; Puttlitz, Christian M.

    2016-11-01

    Computational models of the brain rely on accurate constitutive relationships to model the viscoelastic behavior of brain tissue. Current viscoelastic models have been derived from experiments conducted in a single direction at a time and therefore lack information on the effects of multiaxial loading. It is also unclear if the time-dependent behavior of brain tissue is dependent on either strain magnitude or the direction of loading when subjected to tensile stresses. Therefore, biaxial stress relaxation and cyclic experiments were conducted on corpus callosum tissue isolated from fresh ovine brains. Results demonstrated the relaxation behavior to be independent of strain magnitude, and a quasi-linear viscoelastic (QLV) model was able to accurately fit the experimental data. Also, an isotropic reduced relaxation tensor was sufficient to model the stress-relaxation in both the axonal and transverse directions. The QLV model was fitted to the averaged stress relaxation tests at five strain magnitudes while using the measured strain history from the experiments. The resulting model was able to accurately predict the stresses from cyclic tests at two strain magnitudes. In addition to deriving a constitutive model from the averaged experimental data, each specimen was fitted separately and the resulting distributions of the model parameters were reported and used in a probabilistic analysis to determine the probability distribution of model predictions and the sensitivity of the model to the variance of the parameters. These results can be used to improve the viscoelastic constitutive models used in computational studies of the brain.

  6. Automatic corpus callosum segmentation for standardized MR brain scanning

    NASA Astrophysics Data System (ADS)

    Xu, Qing; Chen, Hong; Zhang, Li; Novak, Carol L.

    2007-03-01

    Magnetic Resonance (MR) brain scanning is often planned manually with the goal of aligning the imaging plane with key anatomic landmarks. The planning is time-consuming and subject to inter- and intra- operator variability. An automatic and standardized planning of brain scans is highly useful for clinical applications, and for maximum utility should work on patients of all ages. In this study, we propose a method for fully automatic planning that utilizes the landmarks from two orthogonal images to define the geometry of the third scanning plane. The corpus callosum (CC) is segmented in sagittal images by an active shape model (ASM), and the result is further improved by weighting the boundary movement with confidence scores and incorporating region based refinement. Based on the extracted contour of the CC, several important landmarks are located and then combined with landmarks from the coronal or transverse plane to define the geometry of the third plane. Our automatic method is tested on 54 MR images from 24 patients and 3 healthy volunteers, with ages ranging from 4 months to 70 years old. The average accuracy with respect to two manually labeled points on the CC is 3.54 mm and 4.19 mm, and differed by an average of 2.48 degrees from the orientation of the line connecting them, demonstrating that our method is sufficiently accurate for clinical use.

  7. Social cognition in individuals with agenesis of the corpus callosum.

    PubMed

    Symington, Scott H; Paul, Lynn K; Symington, Melissa F; Ono, Makoto; Brown, Warren S

    2010-01-01

    Past research has revealed that individuals with agenesis of the corpus callosum (ACC) have deficits in interhemispheric transfer, complex novel problem-solving, and the comprehension of paralinguistic aspects of language. Case studies and family reports also suggest problems in social cognition. The performance of 11 individuals with complete ACC and with normal intelligence was compared to that of 13 IQ- and age-matched controls on three measures of social cognition. Individuals with ACC were indistinguishable from controls on the Happe Theory of Mind Stories and the Adult Faux Pas Test, but performed significantly worse on various portions of the Thames Awareness of Social Inference Test (TASIT) involving interpretations of videotaped social vignettes. Further analysis of the TASIT indicated that individuals with ACC showed deficiency in the recognition of emotion, weakness in understanding paradoxical sarcasm, and particular difficulty interpreting textual versus visual social cues. These results suggest that the tendency for deficient social cognition in individuals with ACC stems from a combination of difficulty integrating information from multiple sources, using paralinguistic cues for emotion, and understanding nonliteral speech. Together, these deficits would contribute to a less robust theory of mind.

  8. Acute infarction of corpus callosum due to transient obstructive hydrocephalus.

    PubMed

    Kaymakamzade, Bahar; Eker, Amber

    2016-01-01

    Acute ischemia of the corpus callosum (CC) is not a well-known feature in patients with acute hydrocephalus. Herein, we describe a case with acute CC infarction due to another rare entity; transient obstructive hydrocephalus. A 66-year-old male was admitted with sudden onset right-sided hemiparesia. CT demonstrated a hematoma on the left basal ganglia with extension to all ventricles. The following day, the patient's neurological status progressed to coma and developed bilateral pyramidal signs. MRI demonstrated obstructive hydrocephalus and acute diffuse infarction accompanied by elevation of the CC. On the same day there was improvement in his neurological status with significant decrease in ventricular size and complete resolution of the clot in the third ventricle. The mechanism of signal abnormalities is probably related with the neural compression of the CC against the falx. Presumably, the clot causing obstruction in the third ventricle dissolved or decayed by the help of fibrinolytic activity of CSF, which was raised after IVH and caused spontaneous improvement of hydrocephalus. Bilateral neurological symptoms suggest diffuse axonal damage and normalization of the intracranial pressure should be performed on the early onset of clinical detorioration in order to prevent axonal injury.

  9. Parametric Probability Distribution Functions for Axon Diameters of Corpus Callosum

    PubMed Central

    Sepehrband, Farshid; Alexander, Daniel C.; Clark, Kristi A.; Kurniawan, Nyoman D.; Yang, Zhengyi; Reutens, David C.

    2016-01-01

    Axon diameter is an important neuroanatomical characteristic of the nervous system that alters in the course of neurological disorders such as multiple sclerosis. Axon diameters vary, even within a fiber bundle, and are not normally distributed. An accurate distribution function is therefore beneficial, either to describe axon diameters that are obtained from a direct measurement technique (e.g., microscopy), or to infer them indirectly (e.g., using diffusion-weighted MRI). The gamma distribution is a common choice for this purpose (particularly for the inferential approach) because it resembles the distribution profile of measured axon diameters which has been consistently shown to be non-negative and right-skewed. In this study we compared a wide range of parametric probability distribution functions against empirical data obtained from electron microscopy images. We observed that the gamma distribution fails to accurately describe the main characteristics of the axon diameter distribution, such as location and scale of the mode and the profile of distribution tails. We also found that the generalized extreme value distribution consistently fitted the measured distribution better than other distribution functions. This suggests that there may be distinct subpopulations of axons in the corpus callosum, each with their own distribution profiles. In addition, we observed that several other distributions outperformed the gamma distribution, yet had the same number of unknown parameters; these were the inverse Gaussian, log normal, log logistic and Birnbaum-Saunders distributions. PMID:27303273

  10. [GENERAL PRINCIPLE OF THE CORPUS CALLOSUM INTERNAL STRUCTURE IN ADULT HUMAN].

    PubMed

    Boiagina, O

    2017-01-01

    The structure of the corpus callosum is a certain form of order of the nerve fibers, glial cells and blood microvessels and it is actually unexplored. We set the goal to understand the general constructive principle of the myeloarchitectonics of human corpus callosum. We used whole mounts of the corpus callosum (5 men and 5 women aged from 36 to 60 years) after their two-week fixation in 10% formalin solution. The next stage was to dissect plate sections of the corpus callosum brainstem in two mutually perpendicular planes. Some of them were subjected to impregnation in 1% osmium tetroxide solution, according to the method adopted in transmission electron microscopy. To prepare these plate sections of the corpus callosum for further study in the light microscope we used the method of plastination in epoxy resin. After complete polymerization plastinated mounts were used for making slices. For further research at high magnification light microscopy they were thinned up to 0.3 mm thickness and were subjected to coloration using 1% solution of methylene blue on 1% borax solution. They were studied using a binocular microscope МБС-9 and microscope "Konus" equipped with digital camera. It was found that the human corpus callosum consists of a number of transversely oriented bands of nerve fibers (commissural cords). Each of them consists of a tightly appressed stratified sections, fascicular rations, which are separated by interstitial layers. In turn, these interfascicular layers give short lateral spurs that divide fascicular rations into individual segments - subfascicular rations. Multiple cells containing interfascicular oligodendrocytes associated with individual subfascicular sets of nerve tracts are dispersed in the cluster order among myelinated nerve fibers of fascicular rations. Fundamentally important point is that the interstitial layers in the corpus callosum as a whole form a complex three-dimensional network structure which is subordinated to the

  11. Proverb comprehension in individuals with agenesis of the corpus callosum.

    PubMed

    Rehmel, Jamie L; Brown, Warren S; Paul, Lynn K

    2016-09-01

    Comprehension of non-literal language involves multiple neural systems likely involving callosal connections. We describe proverb comprehension impairments in individuals with isolated agenesis of the corpus callosum (AgCC) and normal-range general intelligence. Experiment 1 compared Gorham Proverb Test (Gorham, 1956) performance in 19 adults with AgCC and 33 neurotypical control participants of similar age, sex, and intelligence. Experiment 2 used the Proverbs subtest of the Delis-Kaplan Executive Function System (D-KEFS, 2001) to compare 19 adults with AgCC and 17 control participants with similar age, sex, and intelligence. Gorham Proverbs performance was impaired in the AgCC group for both the free-response and multiple-choice tasks. On the D-KEFS proverbs test, the AgCC group performed significantly worse on the free-response task (and all derivative scores) despite normal levels of performance on the multiple-choice task. Covarying verbal intelligence did not alter these outcomes. However, covarying a measure of non-literal language comprehension considerably reduced group differences in proverb comprehension on the Gorham test, but had little effect on the D-KEFS group differences. The difference between groups seemed to be greatest when participants had to generate their own interpretation (free response), or in the multiple choice format when the test included many proverbs that were likely to be less familiar. Taken together, the results of this study clearly show that proverb comprehension is diminished in individuals with AgCC compared to their peers.

  12. Comprehension of humor in primary agenesis of the corpus callosum.

    PubMed

    Brown, Warren S; Paul, Lynn K; Symington, Melissa; Dietrich, Rosalind

    2005-01-01

    Individuals with agenesis of the corpus callosum (ACC) can, in some cases, perform normally on standardized intelligence tests. Nevertheless, recent studies suggest that individuals with ACC and normal IQ scores have deficits in domains of fluid and social intelligence. Anecdotal reports from families suggest diminished appreciation of the subtleties of social interactions, and deficits in the comprehension of jokes and stories. In this research, both the cartoon and narrative joke subtests of a humor test (developed by Brownell et al. [Brownell, H., Michel, D., Powelson, J., & Gardner, H. (1983). Surprise but not coherence: sensitivity to verbal humor in right-hemisphere patients. Brain and language, 18(1), 20-27] and Bihrle et al. [Bihrle, A. M., Brownell, H. H., Powelson, J. A., & Gardner, H. (1986). Comprehension of humorous and non-humorous materials by left and right brain-damaged patients. Brain and Cognition, 5(4), 399-411]) were given to 16 adults with complete ACC (all with IQs>80) and 31 controls of similar age and IQ. Individuals with ACC performed worse than controls on the narrative joke subtest (p<.025) when VIQ was controlled. However, on the cartoon subtest the two groups were not significantly different. Covarying age, forms of IQ, narrative memory, set-switching, and literal language comprehension did not substantially alter the group difference. However, covarying comprehension of nonliteral language and proverbs eliminated the difference, suggesting a common origin for the comprehension of jokes, nonliteral language, and proverbs, most likely related to capacity for understanding second-order meanings.

  13. The combination of thermal dysregulation and agenesis of corpus callosum: Shapiro's or/and reverse Shapiro's syndrome

    PubMed Central

    Topcu, Yasemin; Bayram, Erhan; Karaoglu, Pakize; Yis, Uluc; Kurul, Semra Hiz

    2013-01-01

    Shapiro syndrome is an extremely rare condition consisting the clinical triad of recurrent hypothermia, hyperhydrosis and agenesis of the corpus callosum. On the other hand, reverse Shapiro's sydrome is characterized periodic hyperthermia and agenesis of the corpus callosum. Here, we describe a 3.5-year-old girl with complete agenesis of corpus callosum presenting with recurrent fever and vomiting. She also had hypothermia attacks with accompanying diaphoresis. To the best of our knowledge, there is no described case with episodes of hyperthermia, hypothermia, and vomiting associated with agenesis of the corpus callosum. Recurrent vomiting may be a newly defined symptom associated with these syndromes. PMID:24339619

  14. Lipoma of corpus callosum associated with dysraphic lesions and trisomy 13

    SciTech Connect

    Wainwright, H.; Bowen, R.; Radcliffe, M.

    1995-05-22

    We report on a further case of corpus callosal lipoma and frontal cranial defects. Most cases in the literature of corpus callosal lipoma in association with {open_quotes}dysraphic{close_quotes} lesions have been frontal in location. Malformation of the corpus callosum is said to be associated with 50% of these lipomas. Trisomy 13 was confirmed by the 13q14 cosmid probe on paraffin-embedded liver tissue. 19 refs., 5 figs.

  15. PEDF is a novel oligodendrogenic morphogen acting on the adult SVZ and corpus callosum.

    PubMed

    Sohn, Jiho; Selvaraj, Vimal; Wakayama, Kouji; Orosco, Lori; Lee, Eunyoung; Crawford, Susan E; Guo, Fuzheng; Lang, Jordan; Horiuchi, Makoto; Zarbalis, Konstantinos; Itoh, Takayuki; Deng, Wenbin; Pleasure, David

    2012-08-29

    Pigment epithelium-derived factor (PEDF) is a serine protease inhibitor (serpin) protein with well established neuroprotective and anti-angiogenic properties. Recent studies have also shown that PEDF enhances renewal of adult subventricular zone (SVZ) neural precursors. In neurosphere cultures prepared from the SVZ of adult mice, we found that addition of recombinant PEDF to the medium enhanced expressions of oligodendroglial lineage markers (NG2 and PDGFrα) and transcription factors (Olig1, Olig2, and Sox10). Similarly, continuous PEDF administration into the lateral ventricles of adult glial fibrillary acidic protein:green fluorescent protein (GFAP:GFP) transgenic mice increased the proportions of GFAP:GFP+ and GFAP:GFP- SVZ neural precursors coexpressing oligodendroglial lineage markers and transcription factors. Notably, PEDF infusion also resulted in an induction of doublecortin- and Sox10 double-positive cells in the adult SVZ. Immunoreactive PEDF receptor was detectable in multiple cell types in both adult SVZ and corpus callosum. Furthermore, PEDF intracerebral infusion enhanced survival and maturation of newly born oligodendroglial progenitor cells in the normal corpus callosum, and accelerated oligodendroglial regeneration in lysolecithin-induced corpus callosum demyelinative lesions. Western blot analysis showed a robust upregulation of endogenous PEDF in the corpus callosum upon lysolecithin-induced demyelination. Our results document previously unrecognized oligodendrotrophic effects of recombinant PEDF on the adult SVZ and corpus callosum, demonstrate induction of endogenous CNS PEDF production following demyelination, and make PEDF a strong candidate for pharmacological intervention in demyelinative diseases.

  16. Alien hand syndrome following corpus callosum infarction: A case report and review of the literature.

    PubMed

    Gao, Xiaoyu; Li, Bing; Chu, Wenzheng; Sun, Xuwen; Sun, Chunjuan

    2016-10-01

    Alien hand syndrome (AHS) is characterized by involuntary and autonomous activity of the affected limbs, and consists of the frontal, callosal and posterior AHS variants. The callosal subtype, resulting from damage to the corpus callosum, frequently features intermanual conflict. However, infarction of the corpus callosum is rare due to abundant blood supply. The present study reported a case of AHS (callosal subtype, in the right hand) caused by callosal infarction. Infarction of the left corpus callosum was confirmed with magnetic resonance imaging. In addition, magnetic resonance angiography and digital subtraction angiography examinations revealed multiple lesions in the feeding arteries. Subsequent to antiplatelet therapy for 2 weeks following admission, the patient gradually recovered. Furthermore, the current study reviewed 31 previously reported cases of AHS following callosal infarction in the literature.

  17. Alien hand syndrome following corpus callosum infarction: A case report and review of the literature

    PubMed Central

    Gao, Xiaoyu; Li, Bing; Chu, Wenzheng; Sun, Xuwen; Sun, Chunjuan

    2016-01-01

    Alien hand syndrome (AHS) is characterized by involuntary and autonomous activity of the affected limbs, and consists of the frontal, callosal and posterior AHS variants. The callosal subtype, resulting from damage to the corpus callosum, frequently features intermanual conflict. However, infarction of the corpus callosum is rare due to abundant blood supply. The present study reported a case of AHS (callosal subtype, in the right hand) caused by callosal infarction. Infarction of the left corpus callosum was confirmed with magnetic resonance imaging. In addition, magnetic resonance angiography and digital subtraction angiography examinations revealed multiple lesions in the feeding arteries. Subsequent to antiplatelet therapy for 2 weeks following admission, the patient gradually recovered. Furthermore, the current study reviewed 31 previously reported cases of AHS following callosal infarction in the literature. PMID:27698701

  18. Reversible cerebral periventricular white matter changes with corpus callosum involvement in acute toluene-poisoning.

    PubMed

    Lin, Chih-Ming; Liu, Chi-Kuang

    2015-01-01

    Substance poisoning, such as toluene intoxication, has seldom been reported in the relevant literature. The documented cerebral neuroimaging has mostly described reversible symmetrical white matter changes in both the cerebral and cerebellar hemispheres. This paper presents 2 patients with toluene poisoning, whose brain magnetic resonance imaging studies showed a similar picture that included extra involvement over the corpus callosum; however, such corpus callosum involvement has never been mentioned and is quite rare in the literature. We discussed the underlying neuropathological pathways in this article. Hopefully, these cases will provide first-line clinicians with some valuable information with regard to toluene intoxication and clinical neuroimaging presentations.

  19. Right hand predominant constructional apraxia due to right hemisphere infarction without corpus callosum lesions.

    PubMed

    Kobayashi, Zen; Watanabe, Mayumi; Karibe, Yuri; Nakazawa, Chika; Numasawa, Yoshiyuki; Tomimitsu, Hiroyuki; Shintani, Shuzo

    2014-01-01

    A 74-year-old right-handed woman without cognitive impairment suddenly developed nonfluent aphasia. Brain MRI showed acute infarction in the right frontal lobe and insula without involvement of the corpus callosum. A neurological examination demonstrated not only transcortical motor aphasia, but also ideomotor apraxia and right hand predominant constructional apraxia (CA). To date, right hand predominant CA has only been reported in patients with corpus callosum lesions. The right hand predominant CA observed in our patient may be associated with the failure to transfer information on the spatial structure from the right hemisphere to the motor cortex of the left hemisphere.

  20. Corpus Callosum Area and Brain Volume in Autism Spectrum Disorder: Quantitative Analysis of Structural MRI from the ABIDE Database

    ERIC Educational Resources Information Center

    Kucharsky Hiess, R.; Alter, R.; Sojoudi, S.; Ardekani, B. A.; Kuzniecky, R.; Pardoe, H. R.

    2015-01-01

    Reduced corpus callosum area and increased brain volume are two commonly reported findings in autism spectrum disorder (ASD). We investigated these two correlates in ASD and healthy controls using T1-weighted MRI scans from the Autism Brain Imaging Data Exchange (ABIDE). Automated methods were used to segment the corpus callosum and intracranial…

  1. Exuberant projection into the corpus callosum from the visual cortex of newborn cats.

    PubMed

    Innocenti, G M; Fiore, L; Caminiti, R

    1977-04-01

    In the first postnatal week, neurones projecting into the corpus callosum can be identified in kitten's visual cortex by retrograde transport of HRP. The neurones are located in layers III, IV, and VI. The region of cortex which gives rise to the callosal projection extends beyond its adult boundaries over most of area 17, 18, 19 and in the suprasylvian sulcus.

  2. Moebius syndrome with Dandy-Walker variant and agenesis of corpus callosum.

    PubMed

    John, Jomol Sara; Vanitha, R

    2013-09-01

    Moebius syndrome is a rare congenital neurological disorder. The most frequent mode of presentation is facial diplegia with bilateral lateral rectus palsy, but there are variations. Here, we report a rare case of Moebius syndrome in a 15-month-old child with unilateral facial palsy, bilateral abducens nerve palsy with Dandy Walker variant, and complete agenesis of corpus callosum.

  3. Interhemispheric functional disconnection because of abnormal corpus callosum integrity in bipolar disorder type II

    PubMed Central

    Kudo, Takashi; Matsuoka, Kiwamu; Yamamoto, Akihide; Takahashi, Masato; Nakagawara, Jyoji; Nagatsuka, Kazuyuki; Iida, Hidehiro; Kishimoto, Toshifumi

    2016-01-01

    Background A significantly lower fractional anisotropy (FA) value has been shown in anterior parts of the corpus callosum in patients with bipolar disorder. Aims We investigated the association between abnormal corpus callosum integrity and interhemispheric functional connectivity (IFC) in patients with bipolar disorder. Methods We examined the association between FA values in the corpus callosum (CC-FA) and the IFC between homotopic regions in the anterior cortical structures of bipolar disorder (n=16) and major depressive disorder (n=22) patients with depressed or euthymic states. Results We found a positive correlation between the CC-FA and IFC values between homotopic regions of the ventral prefrontal cortex and insula cortex, and significantly lower IFC between these regions in bipolar disorder patients. Conclusions The abnormal corpus callosum integrity in bipolar disorder patients is relevant to the IFC between homotopic regions, possibly disturbing the exchange of emotional information between the cerebral hemispheres resulting in emotional dysregulation. Declaration of interest None. Copyright and usage © The Royal College of Psychiatrists 2016. This is an open access article distributed under the terms of the Creative Commons Non-Commercial, No Derivatives (CC BY-NC-ND) license. PMID:27847590

  4. Corpus Callosum Size is Linked to Dichotic Deafness and Hemisphericity, Not Sex or Handedness

    ERIC Educational Resources Information Center

    Morton, Bruce E.; Rafto, Stein E.

    2006-01-01

    Individuals differ in the number of corpus callosum (CC) nerve fibers interconnecting their cerebral hemispheres by about threefold. Early reports suggested that males had smaller CCs than females. This was often interpreted to support the concept that the male brain is more "lateralized" or "specialized," thus accounting for presumed male…

  5. Mental State Understanding in Children with Agenesis of the Corpus Callosum

    PubMed Central

    Lábadi, Beatrix; Beke, Anna M.

    2017-01-01

    Impaired social functioning is a well-known outcome of individuals with agenesis of the corpus callosum. Social deficits in nonliteral language comprehension, humor, social reasoning, and recognition of facial expression have all been documented in adults with agenesis of the corpus callosum. In the present study, we examined the emotional and mentalizing deficits that contributing to the social-cognitive development in children with isolated corpus callosum agenesia, including emotion recognition, theory of mind, executive function, working memory, and behavioral impairments as assessed by the parents. The study involved children between the age of 6 and 8 years along with typically developing children who were matched by IQ, age, gender, education, and caregiver's education. The findings indicated that children with agenesis of the corpus callosum exhibited mild impairments in all social factors (recognizing emotions, understanding theory of mind), and showed more behavioral problems than control children. Taken together, these findings suggest that reduced callosal connectivity may contribute to the development of higher-order social-cognitive deficits, involving limits of complex and rapidly occurring social information to be processed. The studies of AgCC shed lights of the role of structural connectivity across the hemispheres in neurodevelopmental disorders. PMID:28220087

  6. A Two-Year Longitudinal MRI Study of the Corpus Callosum in Autism

    ERIC Educational Resources Information Center

    Frazier, Thomas W.; Keshavan, Matcheri S.; Minshew, Nancy J.; Hardan, Antonio Y.

    2012-01-01

    A growing body of literature has identified size reductions of the corpus callosum (CC) in autism. However, to our knowledge, no published studies have reported on the growth of CC volumes in youth with autism. Volumes of the total CC and its sub-divisions were obtained from 23 male children with autism and 23 age- and gender-matched controls at…

  7. Intrahemispheric dysfunction in primary motor cortex without corpus callosum: a transcranial magnetic stimulation study

    PubMed Central

    Fecteau, Shirley; Lassonde, Maryse; Théoret, Hugo

    2006-01-01

    Background The two human cerebral hemispheres are continuously interacting, through excitatory and inhibitory influences and one critical structure subserving this interhemispheric balance is the corpus callosum. Interhemispheric neurophysiological abnormalities and intrahemispheric behavioral impairments have been reported in individuals lacking the corpus callosum. The aim of this study was to examine intrahemispheric neurophysiological function in primary motor cortex devoid of callosal projections. Methods Intracortical excitatory and inhibitory systems were tested in three individuals with complete agenesis of the corpus callosum and sixteen healthy individuals. These systems were assessed using transcranial magnetic stimulation (TMS) protocols: motor threshold at rest, paired-pulse curve, and cortical silent period. Results TMS revealed no difference between the patient and control groups on the motor threshold measure, as well as intracortical facilitation and intracortical inhibition systems as tested by paired stimulation. However, intrahemispheric inhibitory function was found to be abnormal in participants without callosal projections, as the cortical silent period duration was significantly increased in the patient group. Conclusion These data suggest that in addition to previously reported impaired interhemispheric function, patients lacking the entire corpus callosum also display abnormal intrahemispheric excitability of the primary motor cortex. PMID:16790050

  8. Quantitative Analysis of the Shape of the Corpus Callosum in Patients with Autism and Comparison Individuals

    ERIC Educational Resources Information Center

    Casanova, Manuel F.; El-Baz, Ayman; Elnakib, Ahmed; Switala, Andrew E.; Williams, Emily L.; Williams, Diane L.; Minshew, Nancy J.; Conturo, Thomas E.

    2011-01-01

    Multiple studies suggest that the corpus callosum in patients with autism is reduced in size. This study attempts to elucidate the nature of this morphometric abnormality by analyzing the shape of this structure in 17 high-functioning patients with autism and an equal number of comparison participants matched for age, sex, IQ, and handedness. The…

  9. Social and Behavioral Problems of Children with Agenesis of the Corpus Callosum

    ERIC Educational Resources Information Center

    Badaruddin, Denise H.; Andrews, Glena L.; Bolte, Sven; Schilmoeller, Kathryn J.; Schilmoeller, Gary; Paul, Lynn K.; Brown, Warren S.

    2007-01-01

    Archival data from a survey of parent observations was used to determine the prevalence of social and behavioral problems in children with agenesis of the corpus callosum (ACC). Parent observations were surveyed using the Child Behavior Checklist (CBCL) for 61 children with ACC who were selected from the archive based on criteria of motor…

  10. The Brain Connection: The Corpus Callosum is Larger in Left-Handers.

    ERIC Educational Resources Information Center

    Witelson, Sandra F.

    1985-01-01

    Discusses the neurobiological basis for functional specialization of the cerebral hemispheres, indicating that the size of the corpus callosum is correlated with the neurophysiological measure of hand preference. In postmortem examinations of 42 subjects there were no sex differences, but mixed-handers had significantly larger total areas of the…

  11. Mental State Understanding in Children with Agenesis of the Corpus Callosum.

    PubMed

    Lábadi, Beatrix; Beke, Anna M

    2017-01-01

    Impaired social functioning is a well-known outcome of individuals with agenesis of the corpus callosum. Social deficits in nonliteral language comprehension, humor, social reasoning, and recognition of facial expression have all been documented in adults with agenesis of the corpus callosum. In the present study, we examined the emotional and mentalizing deficits that contributing to the social-cognitive development in children with isolated corpus callosum agenesia, including emotion recognition, theory of mind, executive function, working memory, and behavioral impairments as assessed by the parents. The study involved children between the age of 6 and 8 years along with typically developing children who were matched by IQ, age, gender, education, and caregiver's education. The findings indicated that children with agenesis of the corpus callosum exhibited mild impairments in all social factors (recognizing emotions, understanding theory of mind), and showed more behavioral problems than control children. Taken together, these findings suggest that reduced callosal connectivity may contribute to the development of higher-order social-cognitive deficits, involving limits of complex and rapidly occurring social information to be processed. The studies of AgCC shed lights of the role of structural connectivity across the hemispheres in neurodevelopmental disorders.

  12. Tractography of the spider monkey (Ateles geoffroyi) corpus callosum using diffusion tensor magnetic resonance imaging.

    PubMed

    Platas-Neri, Diana; Hidalgo-Tobón, Silvia; de Celis Alonso, Benito; da Celis Alonso, Benito; de León, Fernando Chico-Ponce; Muñoz-Delgado, Jairo; Phillips, Kimberley A

    2015-01-01

    The objective of this research was to describe the organization, connectivity and microstructure of the corpus callosum of the spider monkey (Ateles geoffroyi). Non-invasive magnetic resonance imaging and diffusion-tensor imaging were obtained from three subjects using a 3T Philips scanner. We hypothesized that the arrangement of fibers in spider monkeys would be similar to that observed in other non-human primates. A repeated measure (n = 3) of fractional anisotropy values was obtained of each subject and for each callosal subdivision. Measurements of the diffusion properties of corpus callosum fibers exhibited a similar pattern to those reported in the literature for humans and chimpanzees. No statistical difference was reached when comparing this parameter between the different CC regions (p = 0.066). The highest fractional anisotropy values corresponded to regions projecting from the corpus callosum to the posterior cortical association areas, premotor and supplementary motor cortices. The lowest fractional anisotropy corresponded to projections to motor and sensory cortical areas. Analyses indicated that approximately 57% of the fibers projects to the frontal cortex and 43% to the post-central cortex. While this study had a small sample size, the results provided important information concerning the organization of the corpus callosum in spider monkeys.

  13. Corpus callosum size and diffusion tensor anisotropy in adolescents and adults with schizophrenia.

    PubMed

    Balevich, Emily C; Haznedar, M Mehmet; Wang, Eugene; Newmark, Randall E; Bloom, Rachel; Schneiderman, Jason S; Aronowitz, Jonathan; Tang, Cheuk Y; Chu, King-Wai; Byne, William; Buchsbaum, Monte S; Hazlett, Erin A

    2015-03-30

    The corpus callosum has been implicated as a region of dysfunctional connectivity in schizophrenia, but the association between age and callosal pathology is unclear. Magnetic resonance imaging (MRI) and diffusion-tensor imaging (DTI) were performed on adults (n=34) and adolescents (n=17) with schizophrenia and adult (n=33) and adolescent (n=15) age- and sex-matched healthy controls. The corpus callosum was manually traced on each participant׳s MRI, and the DTI scan was co-registered to the MRI. The corpus callosum was divided into five anteroposterior segments. Area and anisotropy were calculated for each segment. Both patient groups demonstrated reduced callosal anisotropy; however, the adolescents exhibited reductions mostly in anterior regions while the reductions were more prominent in posterior regions of the adults. The adolescent patients showed greater decreases in absolute area as compared with the adult patients, particularly in the anterior segments. However, the adults showed greater reductions when area was considered relative to whole brain white matter volume. Our results suggest that the initial stages of the illness are characterized by deficiencies in frontal connections, and the chronic phase is characterized by deficits in the posterior corpus callosum; or, alternatively, adolescent-onset schizophrenia may represent a different or more severe form of the illness.

  14. Corpus Callosum Morphology in Attention Deficit-Hyperactivity Disorder: Morphometric Analysis of MRI.

    ERIC Educational Resources Information Center

    Hynd, George W.; And Others

    1991-01-01

    Morphometric analysis of magnetic resonance imaging scans revealed that, compared to nondisabled controls, the seven children with attention deficit hyperactivity disorder had a smaller corpus callosum. Results suggest that subtle differences may exist in the brains of these children and that deviations in normal corticogenesis may underlie the…

  15. A 23-Year Review of Communication Development in an Individual with Agenesis of the Corpus Callosum.

    ERIC Educational Resources Information Center

    Stickles, Judith L.; Schilmoeller, Gary L.; Schilmoeller, Kathryn J.

    2002-01-01

    Twenty-three years of observation and testing of the communication skills of a male with agenesis of the corpus callosum and normal IQ revealed initial weakness in language. Difficulties with fluent speech persisted into young adulthood. With intensive intervention, communication and academic skills developed and the participant completed high…

  16. The indusium griseum and the longitudinal striae of the corpus callosum.

    PubMed

    Di Ieva, Antonio; Fathalla, Hussein; Cusimano, Michael D; Tschabitscher, Manfred

    2015-01-01

    In the eighteenth century, Lancisi described the indusium griseum (IG) and the longitudinal striae (LS) of the corpus callosum. The IG is a thin neuronal lamina above the corpus callosum, covered on each side of the midline by the medial and lateral LS. The medial LS (nerves of Lancisi) and lateral LS are two pairs of myelinated fiber bands found in the gray matter of the IG on the dorsal aspect of the corpus callosum. Embryologically, the IG and LS are dorsal remnants of the archicortex of the hippocampus and fornix and thus they are considered components of the limbic system. Recent studies using immunohistochemistry reported that acetylcholine, dopamine, noradrenaline, 5-hydroxytryptamine and GABA neurons innervate the IG. Newer imaging techniques, such as high field MRI and diffusion tensor imaging, provide new tools for studying these structures, whose true function remains still unclear. The present paper reviews the history of the discovery of the IG and LS of the corpus callosum, with a holistic overview on these interesting structures from the anatomical, embryological, neurochemical, radiological and clinical perspective.

  17. Agenesis of the Corpus Callosum: Assessment and Remediation of School-Related Problems.

    ERIC Educational Resources Information Center

    Puente, Antonio, E.

    The paper examines three cases of children born with brain damage (absence of corpus callosum). Common problems (attentional, cognitive, visuo-motor, and motor deficits) are noted, and the impact of secondary emotional involvement is considered. Intervention approaches with two of the children are described as inconsistent and inadequate, while…

  18. Psychological Correlates of Handedness and Corpus Callosum Asymmetry in Autism: The Left Hemisphere Dysfunction Theory Revisited

    ERIC Educational Resources Information Center

    Floris, Dorothea L.; Chura, Lindsay R.; Holt, Rosemary J.; Suckling, John; Bullmore, Edward T.; Baron-Cohen, Simon; Spencer, Michael D.

    2013-01-01

    Rightward cerebral lateralization has been suggested to be involved in the neuropathology of autism spectrum conditions. We investigated functional and neuroanatomical asymmetry, in terms of handedness and corpus callosum measurements in male adolescents with autism, their unaffected siblings and controls, and their associations with executive…

  19. Tractography of the Spider Monkey (Ateles geoffroyi) Corpus Callosum Using Diffusion Tensor Magnetic Resonance Imaging

    PubMed Central

    Platas-Neri, Diana; Hidalgo-Tobón, Silvia; da Celis Alonso, Benito; de León, Fernando Chico-Ponce; Muñoz-Delgado, Jairo; Phillips, Kimberley A.

    2015-01-01

    The objective of this research was to describe the organization, connectivity and microstructure of the corpus callosum of the spider monkey (Ateles geoffroyi). Non-invasive magnetic resonance imaging and diffusion-tensor imaging were obtained from three subjects using a 3T Philips scanner. We hypothesized that the arrangement of fibers in spider monkeys would be similar to that observed in other non-human primates. A repeated measure (n = 3) of fractional anisotropy values was obtained of each subject and for each callosal subdivision. Measurements of the diffusion properties of corpus callosum fibers exhibited a similar pattern to those reported in the literature for humans and chimpanzees. No statistical difference was reached when comparing this parameter between the different CC regions (p = 0.066). The highest fractional anisotropy values corresponded to regions projecting from the corpus callosum to the posterior cortical association areas, premotor and supplementary motor cortices. The lowest fractional anisotropy corresponded to projections to motor and sensory cortical areas. Analyses indicated that approximately 57% of the fibers projects to the frontal cortex and 43% to the post-central cortex. While this study had a small sample size, the results provided important information concerning the organization of the corpus callosum in spider monkeys. PMID:25693078

  20. Reduced White Matter Connectivity in the Corpus Callosum of Children with Tourette Syndrome

    ERIC Educational Resources Information Center

    Plessen, Kerstin J.; Gruner, Renate; Lundervold, Arvid; Hirsch, Jochen G.; Xu, Dongrong; Bansal, Ravi; Hammar, Asa; Lundervold, Astri J.; Wentzel-Larsen, Tore; Lie, Stein Atle; Gass, Achim; Peterson, Bradley S.; Hugdahl, Kenneth

    2006-01-01

    Background: Brain imaging studies have revealed anatomical anomalies in the brains of individuals with Tourette syndrome (TS). Prefrontal regions have been found to be larger and the corpus callosum (CC) area smaller in children and young adults with TS compared with healthy control subjects, and these anatomical features have been understood to…

  1. Progesterone and nestorone promote myelin regeneration in chronic demyelinating lesions of corpus callosum and cerebral cortex.

    PubMed

    El-Etr, Martine; Rame, Marion; Boucher, Celine; Ghoumari, Abdel M; Kumar, Narender; Liere, Philippe; Pianos, Antoine; Schumacher, Michael; Sitruk-Ware, Regine

    2015-01-01

    Multiple Sclerosis affects mainly women and consists in intermittent or chronic damages to the myelin sheaths, focal inflammation, and axonal degeneration. Current therapies are limited to immunomodulators and antiinflammatory drugs, but there is no efficient treatment for stimulating the endogenous capacity of myelin repair. Progesterone and synthetic progestins have been shown in animal models of demyelination to attenuate myelin loss, reduce clinical symptoms severity, modulate inflammatory responses and partially reverse the age-dependent decline in remyelination. Moreover, progesterone has been demonstrated to promote myelin formation in organotypic cultures of cerebellar slices. In the present study, we show that progesterone and the synthetic 19-nor-progesterone derivative Nestorone® promote the repair of severe chronic demyelinating lesions induced by feeding cuprizone to female mice for up to 12 weeks. Progesterone and Nestorone increase the density of NG2(+) oligodendrocyte progenitor cells and CA II(+) mature oligodendrocytes and enhance the formation of myelin basic protein (MBP)- and proteolipid protein (PLP)-immunoreactive myelin. However, while demyelination in response to cuprizone was less marked in corpus callosum than in cerebral cortex, remyelination appeared earlier in the former. The remyelinating effect of progesterone was progesterone receptor (PR)-dependent, as it was absent in PR-knockout mice. Progesterone and Nestorone also decreased (but did not suppress) neuroinflammatory responses, specifically astrocyte and microglial cell activation. Therefore, some progestogens are promising therapeutic candidates for promoting the regeneration of myelin.

  2. Biallelic SZT2 Mutations Cause Infantile Encephalopathy with Epilepsy and Dysmorphic Corpus Callosum

    PubMed Central

    Basel-Vanagaite, Lina; Hershkovitz, Tova; Heyman, Eli; Raspall-Chaure, Miquel; Kakar, Naseebullah; Smirin-Yosef, Pola; Vila-Pueyo, Marta; Kornreich, Liora; Thiele, Holger; Bode, Harald; Lagovsky, Irina; Dahary, Dvir; Haviv, Ami; Hubshman, Monika Weisz; Pasmanik-Chor, Metsada; Nürnberg, Peter; Gothelf, Doron; Kubisch, Christian; Shohat, Mordechai; Macaya, Alfons; Borck, Guntram

    2013-01-01

    Epileptic encephalopathies are genetically heterogeneous severe disorders in which epileptic activity contributes to neurological deterioration. We studied two unrelated children presenting with a distinctive early-onset epileptic encephalopathy characterized by refractory epilepsy and absent developmental milestones, as well as thick and short corpus callosum and persistent cavum septum pellucidum on brain MRI. Using whole-exome sequencing, we identified biallelic mutations in seizure threshold 2 (SZT2) in both affected children. The causative mutations include a homozygous nonsense mutation and a nonsense mutation together with an exonic splice-site mutation in a compound-heterozygous state. The latter mutation leads to exon skipping and premature termination of translation, as shown by RT-PCR in blood RNA of the affected boy. Thus, all three mutations are predicted to result in nonsense-mediated mRNA decay and/or premature protein truncation and thereby loss of SZT2 function. Although the molecular role of the peroxisomal protein SZT2 in neuronal excitability and brain development remains to be defined, Szt2 has been shown to influence seizure threshold and epileptogenesis in mice, consistent with our findings in humans. We conclude that mutations in SZT2 cause a severe type of autosomal-recessive infantile encephalopathy with intractable seizures and distinct neuroradiological anomalies. PMID:23932106

  3. Cognitive impairments associated with corpus callosum infarction: a ten cases study.

    PubMed

    Huang, Xiaoqin; Du, Xiangnan; Song, Haiqing; Zhang, Qian; Jia, Jianping; Xiao, Tianyi; Wu, Jian

    2015-01-01

    The aim of this study was to determine whether the cognitive impairment is associated with corpus callosum infarctions. Ten corpus callosum infarction patients were enrolled in this study. Their emotions, cognitive and language abilities, memory, comprehensive perception were assessed using the Chinese version of following measures: Mini Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), World Health Organization-University of California-Los Angeles Auditory Verbal Learning Test (WHO-UCLA AVLT), Wechsler Adult Intelligence Scale (WAIS) Digit Span subtest and so on. The same measurements were performed on healthy control participants as contrast for analysis. Infarction most frequently occurred in the body and/or splenium of the corpus callosum. The scores of the most cognitive tests in the corpus callosum infarction patients were significantly worse than those of the control participants (P<0.05). Except for the naming ability, the patients showed significantly poorer performance at the overall level of MMSE than the controls did (P<0.05). Consistently, the results of MoCA suggested a significant reduction in visuospatial abilities of execution, orientation, attention, calculation, delayed memory, language, and repetition capabilities in the patients with respect to the control (P<0.05). In addition, the scores in the case group were significantly worse than those in the control group in the auditory word learning test, digital span and Rey complex figure test (P<0.05). Corpus callosum infarction can cause cognitive dysfunction, which poses obstacles to memory in the acute phase, accompanied by different degrees of decline in visuospatial abilities, attention and calculating abilities.

  4. Corpus callosum area and brain volume in autism spectrum disorder: quantitative analysis of structural MRI from the ABIDE database.

    PubMed

    Kucharsky Hiess, R; Alter, R; Sojoudi, S; Ardekani, B A; Kuzniecky, R; Pardoe, H R

    2015-10-01

    Reduced corpus callosum area and increased brain volume are two commonly reported findings in autism spectrum disorder (ASD). We investigated these two correlates in ASD and healthy controls using T1-weighted MRI scans from the Autism Brain Imaging Data Exchange (ABIDE). Automated methods were used to segment the corpus callosum and intracranial region. No difference in the corpus callosum area was found between ASD participants and healthy controls (ASD 598.53 ± 109 mm(2); control 596.82 ± 102 mm(2); p = 0.76). The ASD participants had increased intracranial volume (ASD 1,508,596 ± 170,505 mm(3); control 1,482,732 ± 150,873.5 mm(3); p = 0.042). No evidence was found for overall ASD differences in the corpus callosum subregions.

  5. Non-surgical treatment of massive traumatic corpus callosum hematoma after blunt head injury: A case report.

    PubMed

    Elsayed, A; Elgamal, E; Elsayed, A A; Wasserberg, J; Kuncz, A

    2016-01-01

    Massive hematoma of the corpus callosum caused by blunt head trauma is an extremely rare lesion. Most frequent traumatic lesions involve the corpus callosum are diffuse axonal injuries. They might be associated with small hemorrhagic foci in the hemispheric and brain stem white matter, intraventricular hemorrhages, subarachnoid hemorrhages, traumatic lesions of the septum pellucidum and fornix. Many cases of corpus callosum injury present with permanent disconnection syndrome. We present a case of a 32-year-old female suffered blunt head trauma resulted in massive corpus callosum hematoma which was managed non-surgically. The patient initially had a reduced conscious level and symptoms of disconnection syndrome, and significant recovery was observed at 6 months follow up.

  6. Individual differences in brain asymmetries and fiber composition in the human corpus callosum.

    PubMed

    Aboitiz, F; Scheibel, A B; Fisher, R S; Zaidel, E

    1992-12-11

    There have been several recent reports concerning individual differences in the gross morphometry of the human corpus callosum. However, no studies exist on individual differences in the fiber composition of the corpus callosum. Here we report for the first time the relation of fiber composition in specific callosal segments (as seen in light microscopy) to anatomical asymmetries in language-gifted cortex, as a function of sex. We found a significant negative correlation between Sylvian fissure asymmetries and the total numbers of fibers in the isthmus of males, and in the anterior splenium of females. In addition, a population of relatively large fibers (between 1 micron and 3 microns in diameter) in the isthmus showed a strong negative correlation with perisylvian asymmetries only in males. These findings suggest a sex-dependent, pathway-specific decrease in interhemispheric connectivity with increasing lateralization.

  7. Shape analysis of corpus callosum in phenylketonuria using a new 3D correspondence algorithm

    NASA Astrophysics Data System (ADS)

    He, Qing; Christ, Shawn E.; Karsch, Kevin; Peck, Dawn; Duan, Ye

    2010-03-01

    Statistical shape analysis of brain structures has gained increasing interest from neuroimaging community because it can precisely locate shape differences between healthy and pathological structures. The most difficult and crucial problem is establishing shape correspondence among individual 3D shapes. This paper proposes a new algorithm for 3D shape correspondence. A set of landmarks are sampled on a template shape, and initial correspondence is established between the template and the target shape based on the similarity of locations and normal directions. The landmarks on the target are then refined by iterative thin plate spline. The algorithm is simple and fast, and no spherical mapping is needed. We apply our method to the statistical shape analysis of the corpus callosum (CC) in phenylketonuria (PKU), and significant local shape differences between the patients and the controls are found in the most anterior and posterior aspects of the corpus callosum.

  8. Contralateral targeting of the corpus callosum in normal and pathological brain function.

    PubMed

    Fenlon, Laura R; Richards, Linda J

    2015-05-01

    The corpus callosum connects the two cortical hemispheres of the mammalian brain and is susceptible to structural defects during development, which often result in significant neuropsychological dysfunction. To date, such individuals have been studied primarily with regards to the integrity of the callosal tract at the midline. However, the mechanisms regulating the contralateral targeting of the corpus callosum, after midline crossing has occurred, are less well understood. Recent evidence suggests that defects in contralateral targeting can occur in isolation from midline-tract malformations, and may have significant functional implications. We propose that contralateral targeting is a crucially important and relatively under-investigated event in callosal development, and that defects in this process may constitute an undiagnosed phenotype in several neurological disorders.

  9. Germinoma with an extensive rhabdoid cell component centered at the corpus callosum.

    PubMed

    Tajima, Shogo; Koda, Kenji

    2017-03-01

    Intracranial germinomas comprise 0.5-2.0 % of all central nervous system (CNS) tumors and 50-60 % of CNS germ cell tumors. They most frequently originate in the pineal gland and the suprasellar region. The corpus callosum is an extremely uncommon location for germinoma formation. Herein, we report about a 20-year-old man with a germinoma centered at the corpus callosum and that extended to both cerebral hemispheres. In addition to its location, this case is unique in that the amount of tumor cells with rhabdoid morphology exceeded that of tumor cells with typical morphology. The rhabdoid cell component showed an immunophenotype compatible with germinoma. While the presence of rhabdoid cells is generally regarded as a sign of aggressive behavior, the patient has been doing well for at least 4 years since undergoing radiation therapy and chemotherapy. The cellular composition of germinoma might not critically affect prognosis with adequate treatment.

  10. Developmental changes in the corpus callosum from infancy to early adulthood: a structural magnetic resonance imaging study.

    PubMed

    Tanaka-Arakawa, Megumi M; Matsui, Mie; Tanaka, Chiaki; Uematsu, Akiko; Uda, Satoshi; Miura, Kayoko; Sakai, Tomoko; Noguchi, Kyo

    2015-01-01

    Previous research has reported on the development trajectory of the corpus callosum morphology. However, there have been only a few studies that have included data on infants. The goal of the present study was to examine the morphology of the corpus callosum in healthy participants of both sexes, from infancy to early adulthood. We sought to characterize normal development of the corpus callosum and possible sex differences in development. We performed a morphometric magnetic resonance imaging (MRI) study of 114 healthy individuals, aged 1 month to 25 years old, measuring the size of the corpus callosum. The corpus callosum was segmented into seven subareas of the rostrum, genu, rostral body, anterior midbody, posterior midbody, isthmus and splenium. Locally weighted regression analysis (LOESS) indicated significant non-linear age-related changes regardless of sex, particularly during the first few years of life. After this increase, curve slopes gradually became flat during adolescence and adulthood in both sexes. Age of local maximum for each subarea of the corpus callosum differed across the sexes. Ratios of total corpus callosum and genu, posterior midbody, as well as splenium to the whole brain were significantly higher in females compared with males. The present results demonstrate that the developmental trajectory of the corpus callosum during early life in healthy individuals is non-linear and dynamic. This pattern resembles that found for the cerebral cortex, further suggesting that this period plays a very important role in neural and functional development. In addition, developmental trajectories and changes in growth do show some sex differences.

  11. A de novo mutation in PRICKLE1 in fetal agenesis of the corpus callosum and polymicrogyria

    PubMed Central

    Bassuk, Alexander G.; Sherr, Elliott H.

    2016-01-01

    Homozygous recessive mutations in the PRICKLE1 gene were originally reported in three consanguineous families with myoclonic epilepsy. Subsequently, several studies have identified neurological abnormalities in animal models with both heterozygous and homozygous mutations in PRICKLE1 orthologues, including epilepsy in flies and in mice with heterozygous PRICKLE1 mutations. We describe a fetus with a novel de novo mutation in PRICKLE1 associated with agenesis of the corpus callosum. PMID:26727662

  12. Rare combination of gelastic epilepsy, agenesis of the corpus callosum, and hamartoma.

    PubMed

    Chen, Chia-Chun; Lin, Yu-Ting; Chang, Wen-Cheng; Hsieh, Li-Chun; Liang, Jao-Shwann

    2011-10-01

    Gelastic seizures are rare and are associated with different conditions, but mainly with hypothalamic hamartoma. We report on a boy who presented with mental retardation, aggressive behavior, and generalized tonic-clonic and gelastic seizures. Cranial imaging studies revealed a very rare combination of hypothalamic hamartoma and agenesis of the corpus callosum, which was only reported once previously. His seizure activities demonstrated a modest response to anticonvulsants.

  13. CORPUS CALLOSUM AND EXPERIMENTAL STROKE: STUDIES IN CALLOSOTOMIZED RATS AND ACALLOSAL MICE

    PubMed Central

    Jin, Kunlin; Xie, Lin; Sun, Fen; Mao, XiaoOu; Greenberg, David A.

    2011-01-01

    Background and Purpose Interhemispheric inhibition via the corpus callosum has been proposed as an exacerbating factor in outcome from stroke. Methods We measured infarct volume and behavioral outcome following middle cerebral artery occlusion in callosotomized rats and acallosal mice. Results Neither callosotomy in rats nor callosal agenesis in mice improved infarct volume or behavioral outcome after middle cerebral artery occlusion. Conclusions These findings argue against a role for transcallosal projections in exacerbating focal cerebral ischemia. PMID:21737800

  14. Altered corpus callosum morphology associated with autism over the first 2 years of life.

    PubMed

    Wolff, Jason J; Gerig, Guido; Lewis, John D; Soda, Takahiro; Styner, Martin A; Vachet, Clement; Botteron, Kelly N; Elison, Jed T; Dager, Stephen R; Estes, Annette M; Hazlett, Heather C; Schultz, Robert T; Zwaigenbaum, Lonnie; Piven, Joseph

    2015-07-01

    Numerous brain imaging studies indicate that the corpus callosum is smaller in older children and adults with autism spectrum disorder. However, there are no published studies examining the morphological development of this connective pathway in infants at-risk for the disorder. Magnetic resonance imaging data were collected from 270 infants at high familial risk for autism spectrum disorder and 108 low-risk controls at 6, 12 and 24 months of age, with 83% of infants contributing two or more data points. Fifty-seven children met criteria for ASD based on clinical-best estimate diagnosis at age 2 years. Corpora callosa were measured for area, length and thickness by automated segmentation. We found significantly increased corpus callosum area and thickness in children with autism spectrum disorder starting at 6 months of age. These differences were particularly robust in the anterior corpus callosum at the 6 and 12 month time points. Regression analysis indicated that radial diffusivity in this region, measured by diffusion tensor imaging, inversely predicted thickness. Measures of area and thickness in the first year of life were correlated with repetitive behaviours at age 2 years. In contrast to work from older children and adults, our findings suggest that the corpus callosum may be larger in infants who go on to develop autism spectrum disorder. This result was apparent with or without adjustment for total brain volume. Although we did not see a significant interaction between group and age, cross-sectional data indicated that area and thickness differences diminish by age 2 years. Regression data incorporating diffusion tensor imaging suggest that microstructural properties of callosal white matter, which includes myelination and axon composition, may explain group differences in morphology.

  15. Posterior polymorphous corneal dystrophy 3 is associated with agenesis and hypoplasia of the corpus callosum.

    PubMed

    Jang, Michelle S; Roldan, Ashley N; Frausto, Ricardo F; Aldave, Anthony J

    2014-07-01

    Posterior polymorphous corneal dystrophy (PPCD) is a dominantly inherited disorder of the corneal endothelium that has been associated with mutations in the zinc-finger E-box binding homeobox 1 gene (ZEB1) gene in approximately one-third of affected families. While the corneal dystrophies have traditionally been considered isolated disorders of the corneal endothelium, we have recently identified two cases of maldevelopment of the corpus callosum in unrelated individuals with PPCD. The proband of the first family was diagnosed shortly after birth with agenesis of the corpus callosum and several other developmental abnormalities. Karyotype, FISH and whole genome copy number variant analyses were normal. She was subsequently diagnosed with PPCD, prompting screening of the ZEB1 gene, which identified a novel deletion (c.449delG; p.(Gly150Alafs*36)) present in the heterozygous state that was not identified in either unaffected parent. The proband of the second family was diagnosed several months after birth with thinning of the corpus callosum and PPCD. Whole genome copy number variant analysis revealed a 1.79 Mb duplication of 17q12 in the proband and her father and brother, neither of whom had PPCD. ZEB1 sequencing identified a novel deletion (c.1913-1914delCA; p.(Ser638Cysfs*5)) present in the heterozygous state, which was also identified in the proband's affected mother. Thus, we report the first two cases of the association of PPCD with a developmental abnormality of the brain, in this case maldevelopment of the corpus callosum.

  16. Repeated prenatal corticosteroid administration delays myelination of the corpus callosum in fetal sheep.

    PubMed

    Huang, W L; Harper, C G; Evans, S F; Newnham, J P; Dunlop, S A

    2001-07-01

    Glucocorticoids regulate oligodendrocyte maturation and the myelin biosynthetic pathways. Synthetic glucocorticoids, the corticosteroids have been successfully used in clinical practice as a single course to enhance lung maturation and reduce mortality and morbidity in preterm infants with no long-term neurologic or cognitive side effects. However, a trend has arisen to use repeated courses despite an absence of safety data from clinical trials. We examined the effects of clinically appropriate, maternally administrated, repeated courses of corticosteroids on myelination of the corpus callosum using sheep as a large animal model. The corpus callosum is a major white matter tract that undergoes protracted myelination, underpins higher order cognitive processing and developmental damage to which is associated with, for example, cerebral palsy, mental retardation and attention deficit hyperactivity disorder. Pregnant ewes were given saline or betamethasone (0.5 mg/kg) at 104,111,118 and 124 days gestation, stages equivalent to the third trimester in humans. Lambs were delivered at 145 days (term), perfused and the corpus callosum examined light and electron microscopically. Total axon numbers were unaffected (P>0.05). However, myelination was significantly delayed. Myelinated axons were 5.7% in the experimental group and 9.2% in controls (P<0.05); conversely, unmyelinated axons were 88.3 and 83.7% (P<0.05). Myelinated axon diameter and myelin sheath thickness were also reduced (0.68 vs. 0.94 and 0.11 vs. 0.14 microm, P<0.05). Our data suggest that repeated prenatal corticosteroid administration delays myelination of the corpus callosum and that further safety data are needed to evaluate clinical practice.

  17. Thick corpus callosum: a clue to the diagnosis of fetal septopreoptic holoprosencephaly?

    PubMed

    Koob, Mériam; Weingertner, Anne-sophie; Gasser, Bernard; Oubel, Estanislao; Dietemann, Jean-Louis

    2012-07-01

    We describe fetal septopreoptic holoprosencephaly (HPE) associated with a thick corpus callosum (CC) diagnosed with MRI in a fetus at 31 weeks' gestation. Our report supports a recently published study connecting a thick fetal CC to other brain abnormalities. On diffusion tensor imaging (DTI), the body of the CC contained an abnormal longitudinal bundle, presumed to be a congenital heterotopic cingulum. Prenatal and postmortem brain MRI with DTI, CT, and pathological analyses are described and illustrated.

  18. Corpus callosum size is highly heritable in humans, and may reflect distinct genetic influences on ventral and rostral regions.

    PubMed

    Woldehawariat, Girma; Martinez, Pedro E; Hauser, Peter; Hoover, David M; Drevets, Wayne W C; McMahon, Francis J

    2014-01-01

    Anatomical differences in the corpus callosum have been found in various psychiatric disorders, but data on the genetic contributions to these differences have been limited. The current study used morphometric MRI data to assess the heritability of corpus callosum size and the genetic correlations among anatomical sub-regions of the corpus callosum among individuals with and without mood disorders. The corpus callosum (CC) was manually segmented at the mid-sagittal plane in 42 women (healthy, n = 14; major depressive disorder, n = 15; bipolar disorder, n = 13) and their 86 child or adolescent offspring. Four anatomical sub-regions (CC-genu, CC2, CC3 and CC-splenium) and total CC were measured and analyzed. Heritability and genetic correlations were estimated using a variance components method, with adjustment for age, sex, diagnosis, and diagnosis x age, where appropriate. Significant heritability was found for several CC sub-regions (P<0.01), with estimated values ranging from 48% (splenium) to 67% (total CC). There were strong and significant genetic correlations among most sub regions. Correlations between the genu and mid-body, between the genu and total corpus callosum, and between anterior and mid body were all >90%, but no significant genetic correlations were detected between ventral and rostral regions in this sample. Genetic factors play an important role in corpus callosum size among individuals. Distinct genetic factors seem to be involved in caudal and rostral regions, consistent with the divergent functional specialization of these brain areas.

  19. Functional topography of the corpus callosum investigated by DTI and fMRI

    PubMed Central

    Fabri, Mara; Pierpaoli, Chiara; Barbaresi, Paolo; Polonara, Gabriele

    2014-01-01

    This short review examines the most recent functional studies of the topographic organization of the human corpus callosum, the main interhemispheric commissure. After a brief description of its anatomy, development, microstructure, and function, it examines and discusses the latest findings obtained using diffusion tensor imaging (DTI) and tractography (DTT) and functional magnetic resonance imaging (fMRI), three recently developed imaging techniques that have significantly expanded and refined our knowledge of the commissure. While DTI and DTT have been providing insights into its microstructure, integrity and level of myelination, fMRI has been the key technique in documenting the activation of white matter fibers, particularly in the corpus callosum. By combining DTT and fMRI it has been possible to describe the trajectory of the callosal fibers interconnecting the primary olfactory, gustatory, motor, somatic sensory, auditory and visual cortices at sites where the activation elicited by peripheral stimulation was detected by fMRI. These studies have demonstrated the presence of callosal fiber tracts that cross the commissure at the level of the genu, body, and splenium, at sites showing fMRI activation. Altogether such findings lend further support to the notion that the corpus callosum displays a functional topographic organization that can be explored with fMRI. PMID:25550994

  20. Clinical, genetic and imaging findings identify new causes for corpus callosum development syndromes

    PubMed Central

    Edwards, Timothy J.; Sherr, Elliott H.; Barkovich, A. James

    2014-01-01

    The corpus callosum is the largest fibre tract in the brain, connecting the two cerebral hemispheres, and thereby facilitating the integration of motor and sensory information from the two sides of the body as well as influencing higher cognition associated with executive function, social interaction and language. Agenesis of the corpus callosum is a common brain malformation that can occur either in isolation or in association with congenital syndromes. Understanding the causes of this condition will help improve our knowledge of the critical brain developmental mechanisms required for wiring the brain and provide potential avenues for therapies for callosal agenesis or related neurodevelopmental disorders. Improved genetic studies combined with mouse models and neuroimaging have rapidly expanded the diverse collection of copy number variations and single gene mutations associated with callosal agenesis. At the same time, advances in our understanding of the developmental mechanisms involved in corpus callosum formation have provided insights into the possible causes of these disorders. This review provides the first comprehensive classification of the clinical and genetic features of syndromes associated with callosal agenesis, and provides a genetic and developmental framework for the interpretation of future research that will guide the next advances in the field. PMID:24477430

  1. Structural properties of the human corpus callosum: Multimodal assessment and sex differences.

    PubMed

    Björnholm, L; Nikkinen, J; Kiviniemi, V; Nordström, T; Niemelä, S; Drakesmith, M; Evans, J C; Pike, G B; Veijola, J; Paus, T

    2017-02-22

    A number of structural properties of white matter can be assessed in vivo using multimodal magnetic resonance imaging (MRI). We measured profiles of R1 and R2 relaxation rates, myelin water fraction (MWF) and diffusion tensor measures (fractional anisotropy [FA], mean diffusivity [MD]) across the mid-sagittal section of the corpus callosum in two samples of young individuals. In Part 1, we compared histology-derived axon diameter (Aboitiz et al., 1992) to MRI measures obtained in 402 young men (19.55 ± 0.84 years) recruited from the Avon Longitudinal Study on Parents and Children. In Part 2, we examined sex differences in FA, MD and magnetization transfer ratio (MTR) across the corpus callosum in 433 young (26.50 ± 0.51 years) men and women recruited from the Northern Finland Birth Cohort 1986. We found that R1, R2, and MWF follow the anterior-to-posterior profile of small-axon density. Sex differences in mean MTR were similar across the corpus callosum (males > females) while these in FA differed by the callosal segment (Body: M>F; Splenium: F>M). We suggest that the values of R1, R2 and MWF are driven by high surface area of myelin in regions with high density of "small axons".

  2. Clinical, genetic and imaging findings identify new causes for corpus callosum development syndromes.

    PubMed

    Edwards, Timothy J; Sherr, Elliott H; Barkovich, A James; Richards, Linda J

    2014-06-01

    The corpus callosum is the largest fibre tract in the brain, connecting the two cerebral hemispheres, and thereby facilitating the integration of motor and sensory information from the two sides of the body as well as influencing higher cognition associated with executive function, social interaction and language. Agenesis of the corpus callosum is a common brain malformation that can occur either in isolation or in association with congenital syndromes. Understanding the causes of this condition will help improve our knowledge of the critical brain developmental mechanisms required for wiring the brain and provide potential avenues for therapies for callosal agenesis or related neurodevelopmental disorders. Improved genetic studies combined with mouse models and neuroimaging have rapidly expanded the diverse collection of copy number variations and single gene mutations associated with callosal agenesis. At the same time, advances in our understanding of the developmental mechanisms involved in corpus callosum formation have provided insights into the possible causes of these disorders. This review provides the first comprehensive classification of the clinical and genetic features of syndromes associated with callosal agenesis, and provides a genetic and developmental framework for the interpretation of future research that will guide the next advances in the field.

  3. MIR137HG risk variant rs1625579 genotype is related to corpus callosum volume in schizophrenia.

    PubMed

    Patel, Veena S; Kelly, Sinead; Wright, Carrie; Gupta, Cota Navin; Arias-Vasquez, Alejandro; Perrone-Bizzozero, Nora; Ehrlich, Stefan; Wang, Lei; Bustillo, Juan R; Morris, Derek; Corvin, Aiden; Cannon, Dara M; McDonald, Colm; Donohoe, Gary; Calhoun, Vince D; Turner, Jessica A

    2015-08-18

    Genome-wide association studies implicate the MIR137HG risk variant rs1625579 (MIR137HGrv) within the host gene for microRNA-137 as a potential regulator of schizophrenia susceptibility. We examined the influence of MIR137HGrv genotype on 17 subcortical and callosal volumes in a large sample of individuals with schizophrenia and healthy controls (n=841). Although the volumes were overall reduced relative to healthy controls, for individuals with schizophrenia the homozygous MIR137HGrv risk genotype was associated with attenuated reduction of mid-posterior corpus callosum volume (p=0.001), along with trend-level effects in the adjacent central and posterior corpus callosum. These findings are unique in the literature and remain robust after analysis in ethnically homogenous and single-scanner subsets of the larger sample. Thus, our study suggests that the mechanisms whereby MIR137HGrv works to increase schizophrenia risk are not those that generate the corpus callosum volume reductions commonly found in the disorder.

  4. Shape-based normalization of the corpus callosum for DTI connectivity analysis.

    PubMed

    Sun, Hui; Yushkevich, Paul A; Zhang, Hui; Cook, Philip A; Duda, Jeffrey T; Simon, Tony J; Gee, James C

    2007-09-01

    The continuous medial representation (cm-rep) is an approach that makes it possible to model, normalize, and analyze anatomical structures on the basis of medial geometry. Having recently presented a partial differential equation (PDE)-based approach for 3-D cm-rep modeling [1], here we present an equivalent 2-D approach that involves solving an ordinary differential equation. This paper derives a closed form solution of this equation and shows how Pythagorean hodograph curves can be used to express the solution as a piecewise polynomial function, allowing efficient and robust medial modeling. The utility of the approach in medical image analysis is demonstrated by applying it to the problem of shape-based normalization of the midsagittal section of the corpus callosum. Using diffusion tensor tractography, we show that shape-based normalization aligns subregions of the corpus callosum, defined by connectivity, more accurately than normalization based on volumetric registration. Furthermore, shape-based normalization helps increase the statistical power of group analysis in an experiment where features derived from diffusion tensor tractography are compared between two cohorts. These results suggest that cm-rep is an appropriate tool for normalizing the corpus callosum in white matter studies.

  5. Pediatric neurofunctional intervention in agenesis of the corpus callosum: a case report☆

    PubMed Central

    Pacheco, Sheila Cristina da Silva; Queiroz, Ana Paula Adriano; Niza, Nathália Tiepo; da Costa, Letícia Miranda Resende; Ries, Lilian Gerdi Kittel

    2014-01-01

    Objective: To describe a clinical report pre- and post-neurofunctional intervention in a case of agenesis of the corpus callosum. Case description: Preterm infant with corpus callosum agenesis and hypoplasia of the cerebellum vermis and lateral ventricles, who, at the age of two years, started the proposed intervention. Functional performance tests were used such as the neurofunctional evaluation, the Gross Motor Function Measure and the Gross Motor Function Classification System. In the initial evaluation, absence of equilibrium reactions, postural transfers, deficits in manual and trunk control were observed. The intervention was conducted with a focus on function, prioritizing postural control and guidance of the family to continue care in the home environment. After the intervention, there was an improvement of body reactions, postural control and movement acquisition of hands and limbs. The intervention also showed improvement in functional performance. Comments: Postural control and transfers of positions were benefited by the neurofunction intervention in this case of agenesis of the corpus callosum. The approach based on function with activities that involve muscle strengthening and balance reactions training, influenced the acquisition of a more selective motor behavior. PMID:25479858

  6. Bilateral sensorineural deafness, partial agenesis of the corpus callosum, and arachnoid cysts in two sisters.

    PubMed

    Hendriks, Y M; Laan, L A; Vielvoye, G J; van Haeringen, A

    1999-09-10

    We describe two sisters (ages 10 and 3 years, respectively) with a normal development and a combination of congenital sensorineural hearing loss, partial agenesis of the corpus callosum, arachnoid cyst, and hydrocephalus. Neither girl has distinctive physical anomalies. In the oldest girl, there was a hearing loss of 80 dB bilaterally, and the most severe loss on audiogram was seen at 2,000-4,000 Hz. In the youngest girl, there was a hearing loss of 100 dB bilaterally. Above 2,000 Hz no neural reactions were seen. Cerebral magnetic resonance imaging in one girl and computed tomography in the other showed a partial agenesis of the corpus callosum and a cyst in the pineal region, causing an aqueduct stenosis by compression and consequent hydrocephalus. The parents have normal hearing, and brain magnetic resonance imaging showed no abnormalities. They are nonconsanguineous but from the same small village. This is the first report of a combination of congenital sensorineural hearing loss, partial agenesis of the corpus callosum, and an arachnoid cyst. The pattern of inheritance is probably autosomal recessive.

  7. Rubinstein-Taybi syndrome with agenesis of corpus callosum.

    PubMed

    Mishra, Shubhankar; Agarwalla, Sunil Kumar; Potpalle, Dnyaneshwar Ramesh; Dash, Nishant Nilotpal

    2015-01-01

    Rubinstein-Taybi syndrome (RSTS) is a rare genetic disorder with characteristic morphological anomaly. Our patient was a 4.5-year-old girl came with features like broad thumbs, downward slanting palpebral fissures and mental retardation. Systemic abnormalities such as repeated infection, seizure with developmental delay were also associated with it. She was having head banging behavior abnormal slurring speech, incoordination while transferring things from one hand to other. Galaxy of clinical pictures and magnetic resonance imaging report helped to clinch the diagnosis as a case of "RSTS with corpus callosal agenesis" which to the best of our knowledge has never been reported in past from India.

  8. Selective increase in posterior corpus callosum thickness between the age of 4 and 11years.

    PubMed

    Westerhausen, René; Fjell, Anders M; Krogsrud, Stine K; Rohani, Darius A; Skranes, Jon S; Håberg, Asta K; Walhovd, Kristine B

    2016-06-07

    Establishing an efficient functional and structural connectivity between the two cerebral hemispheres is an important developmental task during childhood, and alterations in this development have accordingly been linked to a series of neurodevelopmental and pediatric disorders. The corpus callosum, the major white-matter structure connecting the hemispheres, has been shown to increase in size throughout the three first decades of life. However, behavioral studies indicate that adult-like performance levels of functional hemispheric interaction are already reached during middle and late childhood. Thus, here we specifically examine the structural development of the corpus callosum during the functionally relevant time period by for the first time (a) selectively addressing prospective childhood development and (b) analyzing a sample in which also younger children are well represented. Corpus callosum anatomy was assessed from 732 T1-weighted MRI datasets acquired from 428 children (213 boys, 215 girls) aged of 4.1 and 10.9years, of which 304 were scanned at two time points. Regional callosal thickness was determined from an outline-based segmentation of the mid-sagittal cross-sectional surface area. Linear-mixed model analyses revealed a significant increase in thickness with age (effect size: up to 15% explained variance) equivalent to a growth in callosal thickness of up to 0.19mm per year in the posterior corpus callosum. The age effect was found to be stronger in posterior segments (i.e., splenium) than in other callosal subregions. Also, the age effect was found to be comparable between boys and girls, and was detected irrespective of whether developmental or individual differences in overall brain size where accounted for or not. Our results demonstrate a selective increase in posterior corpus-callosum thickness during middle and late childhood. Since axons crossing the midline in the splenium mainly connect occipital and parietal cortices, the accentuated

  9. Corpus callosum atrophy is associated with mental slowing and executive deficits in subjects with age‐related white matter hyperintensities: the LADIS Study

    PubMed Central

    Jokinen, Hanna; Ryberg, Charlotte; Kalska, Hely; Ylikoski, Raija; Rostrup, Egill; Stegmann, Mikkel B; Waldemar, Gunhild; Madureira, Sofia; Ferro, José M; van Straaten, Elizabeth C W; Scheltens, Philip; Barkhof, Frederik; Fazekas, Franz; Schmidt, Reinhold; Carlucci, Giovanna; Pantoni, Leonardo; Inzitari, Domenico; Erkinjuntti, Timo

    2007-01-01

    Background Previous research has indicated that corpus callosum atrophy is associated with global cognitive decline in neurodegenerative diseases, but few studies have investigated specific cognitive functions. Objective To investigate the role of regional corpus callosum atrophy in mental speed, attention and executive functions in subjects with age‐related white matter hyperintensities (WMH). Methods In the Leukoaraiosis and Disability Study, 567 subjects with age‐related WMH were examined with a detailed neuropsychological assessment and quantitative magnetic resonance imaging. The relationships of the total corpus callosum area and its subregions with cognitive performance were analysed using multiple linear regression, controlling for volume of WMH and other confounding factors. Results Atrophy of the total corpus callosum area was associated with poor performance in tests assessing speed of mental processing—namely, trail making A and Stroop test parts I and II. Anterior, but not posterior, corpus callosum atrophy was associated with deficits of attention and executive functions as reflected by the symbol digit modalities and digit cancellation tests, as well as by the subtraction scores in the trail making and Stroop tests. Furthermore, semantic verbal fluency was related to the total corpus callosum area and the isthmus subregion. Conclusions Corpus callosum atrophy seems to contribute to cognitive decline independently of age, education, coexisting WMH and stroke. Anterior corpus callosum atrophy is related to the frontal‐lobe‐mediated executive functions and attention, whereas overall corpus callosum atrophy is associated with the slowing of processing speed. PMID:17028118

  10. Positive correlations between corpus callosum thickness and intelligence.

    PubMed

    Luders, Eileen; Narr, Katherine L; Bilder, Robert M; Thompson, Paul M; Szeszko, Philip R; Hamilton, Liberty; Toga, Arthur W

    2007-10-01

    Callosal morphology is thought to reflect the capacity for inter-hemispheric communication and thus, in addition to other cerebral characteristics, may serve as a neuroanatomical substrate of general intellectual capacity. We applied novel computational mesh-based methods to establish the presence and direction of correlations between intelligence and callosal thickness at high spatial resolution while removing the variance associated with overall brain size. Within healthy subjects (n=62), and within males (n=28) and females (n=34) separately, we observed significant positive correlations between callosal morphology and intelligence measures (full-scale, performance, and verbal). These relationships were pronounced in posterior callosal sections and were confirmed by permutation testing. Significant negative correlations were absent. Positive associations between intelligence and posterior callosal thickness may reflect a more efficient inter-hemispheric information transfer, positively affecting information processing and integration, and thus intellectual performance. At the same time, regional variations in callosal size might also partly reflect the underlying architecture of topographically connected cortical regions relevant for processing higher-order cognitive information. Our findings emphasize the importance of incorporating posterior (callosal) regions into the theories and models proposed to explain the anatomical substrates of intelligence.

  11. Enriched environment increases the total number of CNPase positive cells in the corpus callosum of middle-aged rats.

    PubMed

    Zhao, Yuan-Yu; Shi, Xiao-Yan; Qiu, Xuan; Zhang, Lei; Lu, Wei; Yang, Shu; Li, Chen; Cheng, Guo-Hua; Yang, Zheng-Wei; Tang, Yong

    2011-01-01

    It had been reported that enriched environment was beneficial for the brain cognition, neurons and synapses in cortex and hippocampus. With diffusion tensor imaging (DTI), several studies recently found the trained-induced larger corpus callosum. However, the effect of enriched environment on the oligodendrocytes in corpus callosum has not been explored with the unbiased stereological methods. In current study, the effect of enriched environment on the total number of 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase) positive cells in middle-aged rat corpus callosum was investigated by means of immunohistochemical techniques and the unbiased stereological methods. We found that, when compared to standard rats, the spatial learning capacity of enriched-environment rats was significantly increased. The total number of the CNPase positive cells in the corpus callosum of enriched-environment middle-aged rats was significantly increased when compared to standard rats. The present study provided, to the best of our knowledge, the first evidence of environmental enrichment-induced increases in the total number of CNPase positive cells in the corpus callosum of middle-aged rats.

  12. The effect of injury timing on white matter changes in the corpus callosum following unilateral brain injury.

    PubMed

    Hawe, Rachel L; Sukal-Moulton, Theresa; Dewald, Julius P A

    2013-01-01

    Motor impairments following unilateral brain injuries may be related to changes in the corpus callosum. The purpose of this study was to determine if the corpus callosum is impacted differently in pediatric versus adult hemiplegia. Diffusion tensor imaging was completed on 41 participants (11 pediatric hemiplegia, 10 adult hemiplegia, 10 pediatric control and 10 adult control). Fractional anisotropy values and cross-sectional areas for five regions of the corpus callosum were compared between subject groups. Additionally, the amount of involuntary activity in the paretic elbow was quantified during non-paretic elbow flexion tasks for a subset of pediatric hemiplegia participants. Fractional anisotropy values were reduced in pediatric hemiplegia compared to pediatric control subjects in callosal regions corresponding to premotor and supplementary motor areas, primary sensory cortex, and parietal, temporal, and occipital cortices. Differences in fractional anisotropy between adult stroke and adult controls were only found in the region corresponding to parietal, temporal, and occipital cortices. Cross-sectional area was affected in all regions of the corpus callosum in pediatric hemiplegia, but only in the primary sensory region in adult hemiplegia. Additionally, changes in the cross-sectional areas were correlated with involuntary mirror movements in the pediatric hemiplegia group. In conclusion, the corpus callosum is affected to a greater extent in pediatric compared to adult hemiplegia, which may explain why unsuppressed mirror movements and difficulty with bimanual coordination are greater problems in this population.

  13. Microglia shape corpus callosum axon tract fasciculation: functional impact of prenatal inflammation.

    PubMed

    Pont-Lezica, Lorena; Beumer, Wouter; Colasse, Sabrina; Drexhage, Hemmo; Versnel, Marjan; Bessis, Alain

    2014-05-01

    Microglia colonise the brain parenchyma at early stages of development and accumulate in specific regions where they participate in cell death, angiogenesis, neurogenesis and synapse elimination. A recurring feature of embryonic microglial is their association with developing axon tracts, which, together with in vitro data, supports the idea of a physiological role for microglia in neurite development. Yet the demonstration of this role of microglia is lacking. Here, we have studied the consequences of microglial dysfunction on the formation of the corpus callosum, the largest commissure of the mammalian brain, which shows consistent microglial accumulation during development. We studied two models of microglial dysfunction: the loss-of-function of DAP12, a key microglial-specific signalling molecule, and a model of maternal inflammation by peritoneal injection of lipopolysaccharide at embryonic day (E)15.5. We also took advantage of the Pu.1(-/-) mouse line, which is devoid of microglia. We performed transcriptional profiling of maternally inflamed and Dap12-mutant microglia at E17.5. The two treatments principally down-regulated genes involved in nervous system development and function, particularly in neurite formation. We then analysed the developmental consequences of these microglial dysfunctions on the formation of the corpus callosum. We show that all three models of altered microglial activity resulted in the defasciculation of dorsal callosal axons. Our study demonstrates that microglia display a neurite-development-promoting function and are genuine actors of corpus callosum development. It further shows that microglial activation impinges on this function, thereby revealing that prenatal inflammation impairs neuronal development through a loss of trophic support.

  14. Effects of prenatal irradiation on the development of cerebral cortex and corpus callosum of the mouse

    SciTech Connect

    Schmidt, S.L.; Lent, R.

    1987-10-08

    Defects of the cerebral cortex and corpus callosum of mice subjected prenatally to gamma irradiation were evaluated as a function of dose and of embryonic age at irradiation. Pregnant mice were exposed to a gamma source at 16, 17, and 19 days of gestation (E16, E17, and E19, respectively), with total doses of 2 Gy and 3 Gy, in order to produce brain defects on their progeny. At 60 postnatal days, the brains of the offspring were analyzed qualitatively and quantitatively and compared with those of nonirradiated animals. Mice irradiated at E16 were all acallosal. Those that were exposed to 2 Gy displayed an aberrant longitudinal bundle typical of other acallosals, but this was not the case in those irradiated with 3 Gy. The corpus callosum of animals irradiated at E17 with 3 Gy was pronouncedly hypotrophic, but milder effects were observed in the other groups. Quantitative analysis confirmed a dependence of callosal midsagittal area upon dose and age at irradiation, and, in addition, indicated an interaction between these variables. The neocortex of irradiated animals was hypotrophic: layers II-III were much more affected than layer V, and this was more affected than layer VI. Quantitative analysis indicated that this effect also depended on dose and age at irradiation and that it was due to a loss of cortical neurons. Furthermore, a positive correlation was found between the number of neurons within layers II-III, and V and the midsagittal area of the corpus callosum. Ectopic neurons were found in the white matter and in layer I of animals irradiated at E16 and E17, indicating that fetal exposure to ionizing radiation interfered with the migration of cortical neuroblasts.

  15. Automatic corpus callosum segmentation using a deformable active Fourier contour model

    NASA Astrophysics Data System (ADS)

    Vachet, Clement; Yvernault, Benjamin; Bhatt, Kshamta; Smith, Rachel G.; Gerig, Guido; Cody Hazlett, Heather; Styner, Martin

    2012-03-01

    The corpus callosum (CC) is a structure of interest in many neuroimaging studies of neuro-developmental pathology such as autism. It plays an integral role in relaying sensory, motor and cognitive information from homologous regions in both hemispheres. We have developed a framework that allows automatic segmentation of the corpus callosum and its lobar subdivisions. Our approach employs constrained elastic deformation of flexible Fourier contour model, and is an extension of Szekely's 2D Fourier descriptor based Active Shape Model. The shape and appearance model, derived from a large mixed population of 150+ subjects, is described with complex Fourier descriptors in a principal component shape space. Using MNI space aligned T1w MRI data, the CC segmentation is initialized on the mid-sagittal plane using the tissue segmentation. A multi-step optimization strategy, with two constrained steps and a final unconstrained step, is then applied. If needed, interactive segmentation can be performed via contour repulsion points. Lobar connectivity based parcellation of the corpus callosum can finally be computed via the use of a probabilistic CC subdivision model. Our analysis framework has been integrated in an open-source, end-to-end application called CCSeg both with a command line and Qt-based graphical user interface (available on NITRC). A study has been performed to quantify the reliability of the semi-automatic segmentation on a small pediatric dataset. Using 5 subjects randomly segmented 3 times by two experts, the intra-class correlation coefficient showed a superb reliability (0.99). CCSeg is currently applied to a large longitudinal pediatric study of brain development in autism.

  16. Wnt/Calcium Signaling Mediates Axon Growth and Guidance in the Developing Corpus Callosum

    PubMed Central

    Hutchins, B Ian; Li, Li; Kalil, Katherine

    2011-01-01

    It has been shown in vivo that Wnt5a gradients surround the corpus callosum and guide callosal axons after the midline (postcrossing) by Wnt5a-induced repulsion via Ryk receptors. In dissociated cortical cultures we showed that Wnt5a simultaneously promotes axon outgrowth and repulsion by calcium signaling. Here to test the role of Wnt5a/calcium signaling in a complex in vivo environment we used sensorimotor cortical slices containing the developing corpus callosum. Plasmids encoding the cytoplasmic marker DsRed and the genetically encoded calcium indicator GCaMP2 were electroporated into one cortical hemisphere. Postcrossing callosal axons grew 50% faster than pre-crossing axons and higher frequencies of calcium transients in axons and growth cones correlated well with outgrowth. Application of pharmacological inhibitors to the slices showed that signaling pathways involving calcium release through IP3 receptors and calcium entry through TRP channels regulate post-crossing axon outgrowth and guidance. Co-electroporation of Ryk siRNA and DsRed revealed that knock down of the Ryk receptor reduced outgrowth rates of postcrossing but not precrossing axons by 50% and caused axon misrouting. Guidance errors in axons with Ryk knockdown resulted from reduced calcium activity. In the corpus callosum CaMKII inhibition reduced the outgrowth rate of postcrossing (but not precrossing) axons and caused severe guidance errors which resulted from reduced CaMKII-dependent repulsion downstream of Wnt/calcium. We show for the first time that Wnt/Ryk calcium signaling mechanisms regulating axon outgrowth and repulsion in cortical cultures are also essential for the proper growth and guidance of postcrossing callosal axons which involve axon repulsion through CaMKII. © 2010 Wiley Periodicals, Inc. Develop Neurobiol 71: 269–283, 2011. PMID:20936661

  17. Agenesis of the corpus callosum in a child with Leber's congenital amaurosis.

    PubMed

    Kiratli, H; Tatlipinar, S

    1999-09-01

    A 2.5-year-old male infant with agenesis of the corpus callosum and Leber's congenital amaurosis is described. The infant had nystagmus as the presenting sign. The fundi showed circumscribed macular atrophy with encircling retinal pigment epithelial hyperplasia (macular coloboma-like lesions), attenuation of the retinal arterioles, and very fine pigment dusting in the peripheral retina. Photopic and scotopic ERG were extinguished. Even though this is an exceedingly rare association, these findings along with neurological symptoms should alert the physician to conduct prompt cranial imaging.

  18. Humero-radial synostosis, microcephaly, short corpus callosum, and abnormal genitalia in sibs.

    PubMed

    Guilherme, Romain; Baumann, Clarisse; Garel, Catherine; Huten, Yolène; Oury, Jean-François; Delezoide, Anne-Lise

    2008-07-15

    We report on two male sib fetuses with humero-radial synostosis and thumb hypoplasia, microcephaly with simplified gyral pattern, short corpus callosum and ambiguous genitalia. The main clinical, anatomopathological and imaging findings are presented and compared with previous cases of humero-radial synostosis as a prominent manifestation and with the X-linked lissencephaly with ambiguous genitalia syndrome (X-LAG). To our knowledge, this combination of anomalies has never been described before, and we propose that this disorder comprises a new humero-radial synostosis syndrome with an autosomal recessive or X-linked pattern of inheritance.

  19. Structural Organization of the Corpus Callosum Predicts Attentional Shifts after Continuous Theta Burst Stimulation

    PubMed Central

    Humphreys, Glyn W.; Sotiropoulos, Stamatios N.; Kennard, Christopher; Cazzoli, Dario

    2015-01-01

    Repetitive transcranial magnetic stimulation (rTMS) applied over the right posterior parietal cortex (PPC) in healthy participants has been shown to trigger a significant rightward shift in the spatial allocation of visual attention, temporarily mimicking spatial deficits observed in neglect. In contrast, rTMS applied over the left PPC triggers a weaker or null attentional shift. However, large interindividual differences in responses to rTMS have been reported. Studies measuring changes in brain activation suggest that the effects of rTMS may depend on both interhemispheric and intrahemispheric interactions between cortical loci controlling visual attention. Here, we investigated whether variability in the structural organization of human white matter pathways subserving visual attention, as assessed by diffusion magnetic resonance imaging and tractography, could explain interindividual differences in the effects of rTMS. Most participants showed a rightward shift in the allocation of spatial attention after rTMS over the right intraparietal sulcus (IPS), but the size of this effect varied largely across participants. Conversely, rTMS over the left IPS resulted in strikingly opposed individual responses, with some participants responding with rightward and some with leftward attentional shifts. We demonstrate that microstructural and macrostructural variability within the corpus callosum, consistent with differential effects on cross-hemispheric interactions, predicts both the extent and the direction of the response to rTMS. Together, our findings suggest that the corpus callosum may have a dual inhibitory and excitatory function in maintaining the interhemispheric dynamics that underlie the allocation of spatial attention. SIGNIFICANCE STATEMENT The posterior parietal cortex (PPC) controls allocation of attention across left versus right visual fields. Damage to this area results in neglect, characterized by a lack of spatial awareness of the side of space

  20. Gender-based differences in the shape of the human corpus callosum are associated with allometric variations.

    PubMed

    Bruner, Emiliano; de la Cuétara, José Manuel; Colom, Roberto; Martin-Loeches, Manuel

    2012-04-01

    The corpus callosum displays considerable morphological variability between individuals. Although some characteristics are thought to differ between male and female brains, there is no agreement regarding the source of this variation. Biomedical imaging and geometric morphometrics have provided tools to investigate shape and size variation in terms of integration and correlation. Here we analyze variations at the midsagittal outline of the corpus callosum in a sample of 102 young adults in order to describe and quantify the pattern of covariation associated with its morphology. Our results suggest that the shape of the corpus callosum is characterized by low levels of morphological integration, which explains the large variability. In larger brains, a minor allometric component involves a relative reduction of the splenium. Small differences between males and?females are associated with this allometric pattern, induced primarily by size variation rather than gender-specific characteristics.

  1. Age-Specific Dynamics of Corpus Callosum Development in Children and its Peculiarities in Infantile Cerebral Palsy.

    PubMed

    Krasnoshchekova, E I; Zykin, P A; Tkachenko, L A; Aleksandrov, T A; Sereda, V M; Yalfimov, A N

    2016-10-01

    The age dynamics of corpus callosum development was studied on magnetic resonance images of the brain in children aged 2-11 years without neurological abnormalities and with infantile cerebral palsy. The areas of the total corpus callosum and its segments are compared in the midsagittal images. Analysis is carried out with the use of an original formula: proportion of areas of the anterior (genu, CC2; and anterior part, CC3) and posterior (isthmus, CC6 and splenium, CC7) segments: kCC=(CC2+CC3)×CC6/CC7. The results characterize age-specific dynamics of the corpus callosum development and can be used for differentiation, with high confidence, of the brain of children without neurological abnormalities from the brain patients with infantile cerebral palsy.

  2. Msh2 deficiency leads to dysmyelination of the corpus callosum, impaired locomotion, and altered sensory function in mice

    PubMed Central

    Diouf, Barthelemy; Devaraju, Prakash; Janke, Laura J.; Fan, Yiping; Frase, Sharon; Eddins, Donnie; Peters, Jennifer L.; Kim, Jieun; Pei, Deqing; Cheng, Cheng; Zakharenko, Stanislav S.; Evans, William E.

    2016-01-01

    A feature in patients with constitutional DNA-mismatch repair deficiency is agenesis of the corpus callosum, the cause of which has not been established. Here we report a previously unrecognized consequence of deficiency in MSH2, a protein known primarily for its function in correcting nucleotide mismatches or insertions and deletions in duplex DNA caused by errors in DNA replication or recombination. We documented that Msh2 deficiency causes dysmyelination of the axonal projections in the corpus callosum. Evoked action potentials in the myelinated corpus callosum projections of Msh2-null mice were smaller than wild-type mice, whereas unmyelinated axons showed no difference. Msh2-null mice were also impaired in locomotive activity and had an abnormal response to heat. These findings reveal a novel pathogenic consequence of MSH2 deficiency, providing a new mechanistic hint to previously recognized neurological disorders in patients with inherited DNA-mismatch repair deficiency. PMID:27476972

  3. The corpus callosum in monozygotic twins concordant and discordant for handedness and language dominance.

    PubMed

    Häberling, Isabelle S; Badzakova-Trajkov, Gjurgjica; Corballis, Michael C

    2012-10-01

    We used diffusion tensor imaging to assess callosal morphology in 35 pairs of monozygotic twins, of which 17 pairs were concordant for handedness and 18 pairs were discordant for handedness. Functional hemispheric language dominance was established for each twin member using fMRI, resulting in 26 twin pairs concordant and 9 twin pairs discordant for language dominance. On the basis of genetic models of handedness and language dominance, which assume one "right shift" (RS) gene with two alleles, an RS+ allele biasing toward right-handedness and left cerebral language dominance and an RS- allele leaving both asymmetries to chance, all twins were classified according to their putative genotypes, and the possible effects of the gene on callosal morphology was assessed. Whereas callosal size was under a high genetic control that was independent of handedness and language dominance, twin pairs with a high probability of carrying the putative RS+ allele showed a connectivity pattern characterized by a genetically controlled, low anisotropic diffusion over the whole corpus callosum. In contrast, the high connectivity pattern exhibited by twin pairs more likely to lack the RS+ allele was under significantly less genetic influence. The data suggest that handedness and hemispheric dominance for speech production might be at least partly dependent on genetically controlled processes of axonal pruning in the corpus callosum.

  4. Impaired Levels of Gangliosides in the Corpus Callosum of Huntington Disease Animal Models

    PubMed Central

    Di Pardo, Alba; Amico, Enrico; Maglione, Vittorio

    2016-01-01

    Huntington Disease (HD) is a genetic neurodegenerative disorder characterized by broad types of cellular and molecular dysfunctions that may affect both neuronal and non-neuronal cell populations. Among all the molecular mechanisms underlying the complex pathogenesis of the disease, alteration of sphingolipids has been identified as one of the most important determinants in the last years. In the present study, besides the purpose of further confirming the evidence of perturbed metabolism of gangliosides GM1, GD1a, and GT1b the most abundant cerebral glycosphingolipids, in the striatal and cortical tissues of HD transgenic mice, we aimed to test the hypothesis that abnormal levels of these lipids may be found also in the corpus callosum white matter, a ganglioside-enriched brain region described being dysfunctional early in the disease. Semi-quantitative analysis of GM1, GD1a, and GT1b content indicated that ganglioside metabolism is a common feature in two different HD animal models (YAC128 and R6/2 mice) and importantly, demonstrated that levels of these gangliosides were significantly reduced in the corpus callosum white matter of both models starting from the early stages of the disease. Besides corroborating the evidence of aberrant ganglioside metabolism in HD, here, we found out for the first time, that ganglioside dysfunction is an early event in HD models and it may potentially represent a critical molecular change influencing the pathogenesis of the disease. PMID:27766070

  5. The Corpus Callosum and the Visual Cortex: Plasticity Is a Game for Two

    PubMed Central

    Pietrasanta, Marta; Restani, Laura; Caleo, Matteo

    2012-01-01

    Throughout life, experience shapes and selects the most appropriate brain functional connectivity to adapt to a changing environment. An ideal system to study experience-dependent plasticity is the visual cortex, because visual experience can be easily manipulated. In this paper, we focus on the role of interhemispheric, transcallosal projections in experience-dependent plasticity of the visual cortex. We review data showing that deprivation of sensory experience can modify the morphology of callosal fibres, thus altering the communication between the two hemispheres. More importantly, manipulation of callosal input activity during an early critical period alters developmental maturation of functional properties in visual cortex and modifies its ability to remodel in response to experience. We also discuss recent data in rat visual cortex, demonstrating that the corpus callosum plays a role in binocularity of cortical neurons and is involved in the plastic shift of eye preference that follows a period of monocular eyelid suture (monocular deprivation) in early age. Thus, experience can modify the fine connectivity of the corpus callosum, and callosal connections represent a major pathway through which experience can mediate functional maturation and plastic rearrangements in the visual cortex. PMID:22792494

  6. Shape analysis of corpus callosum in autism subtype using planar conformal mapping

    NASA Astrophysics Data System (ADS)

    He, Qing; Duan, Ye; Yin, Xiaotian; Gu, Xianfeng; Karsch, Kevin; Miles, Judith

    2009-02-01

    A number of studies have documented that autism has a neurobiological basis, but the anatomical extent of these neurobiological abnormalities is largely unknown. In this study, we aimed at analyzing highly localized shape abnormalities of the corpus callosum in a homogeneous group of autism children. Thirty patients with essential autism and twenty-four controls participated in this study. 2D contours of the corpus callosum were extracted from MR images by a semiautomatic segmentation method, and the 3D model was constructed by stacking the contours. The resulting 3D model had two openings at the ends, thus a new conformal parameterization for high genus surfaces was applied in our shape analysis work, which mapped each surface onto a planar domain. Surface matching among different individual meshes was achieved by re-triangulating each mesh according to a template surface. Statistical shape analysis was used to compare the 3D shapes point by point between patients with autism and their controls. The results revealed significant abnormalities in the anterior most and anterior body in essential autism group.

  7. Corpus callosum analysis using MDL-based sequential models of shape and appearance

    NASA Astrophysics Data System (ADS)

    Stegmann, Mikkel B.; Davies, Rhodri H.; Ryberg, Charlotte

    2004-05-01

    This paper describes a method for automatically analysing and segmenting the corpus callosum from magnetic resonance images of the brain based on the widely used Active Appearance Models (AAMs) by Cootes et al. Extensions of the original method, which are designed to improve this specific case are proposed, but all remain applicable to other domain problems. The well-known multi-resolution AAM optimisation is extended to include sequential relaxations on texture resolution, model coverage and model parameter constraints. Fully unsupervised analysis is obtained by exploiting model parameter convergence limits and a maximum likelihood estimate of shape and pose. Further, the important problem of modelling object neighbourhood is addressed. Finally, we describe how correspondence across images is achieved by selecting the minimum description length (MDL) landmarks from a set of training boundaries using the recently proposed method of Davies et al. This MDL-approach ensures a unique parameterisation of corpus callosum contour variation, which is crucial for neurological studies that compare reference areas such as rostrum, splenium, et cetera. We present quantitative and qualitative results that show that the method produces accurate, robust and rapid segmentations in a cross sectional study of 17 subjects, establishing its feasibility as a fully automated clinical tool for analysis and segmentation.

  8. Structural and Functional Reorganization of the Corpus Callosum between the Age of 6 and 8 Years

    PubMed Central

    Luders, Eileen; Specht, Karsten; Ofte, Sonja H.; Toga, Arthur W.; Thompson, Paul M.; Helland, Turid; Hugdahl, Kenneth

    2011-01-01

    The establishment of an efficient exchange of information between the cerebral hemispheres is of crucial importance in the developing functionally lateralized brain. The corpus callosum, the major connection between the cerebral hemispheres, grows constantly throughout childhood and adolescence. However, behavioral studies suggest the existence of a critical time period for callosal functional development starting around the age of 6 years. In the present longitudinal study, examining a cohort of 20 children at the age of 6 and 8 years, we assessed the relationship between structural and functional callosal development during this time period. The structural development was quantified by calculating the increase in callosal thickness using a shape-based computational analysis of the mid-sagittal corpus callosum as obtained with magnetic resonance imaging. The functional development was assessed with a speech discrimination task based on the dichotic presentation of consonant–vowel syllables. The statistical analysis revealed that children whose callosal isthmus increased in thickness over the course of 2 years showed a decrease in interhemispheric information transfer. However, children exhibiting a decrease in isthmus thickness revealed an increase in information transfer. These results might indicate a refinement process of the callosal connections to optimize the neuronal communication between the developing cerebral hemispheres. PMID:20847151

  9. Polymicrogyria, Large Corpus Callosum and Psychomotor Retardation in Four-Year-Old Girl: Potential Association Based on MR Findings

    PubMed Central

    Budai, Caterina; Moscato, Giulia; Patruno, Francesco; Leonardi, Marco; Maffei, Monica

    2014-01-01

    Summary We describe a child from consanguineous parents presenting mega corpus callosum (MegaCC), polymicrogyria, psychomotor retardation with swallowing difficulties and language impairment perhaps linked to the syndrome of megalencephaly-polymicrogyria-mega corpus callosum (MEG-PMG-MegaCC). Reviewing the literature, we speculate that MegaCC, psychomotor retardation and anomalies in cortical migration are the three pathognomonic features. The presence of additional possibly associated anomalies such as megalencephaly, indicates that the spectrum of linked malformations with this rare syndrome is broad and yet to be defined. PMID:25260206

  10. Aging and the myelinated fibers in prefrontal cortex and corpus callosum of the monkey.

    PubMed

    Peters, Alan; Sethares, Claire

    2002-01-14

    In the rhesus monkey, the myelin sheaths of nerve fibers in area 46 of prefrontal cortex and in splenium of the corpus callosum show age-related alterations in their structure. The alterations are of four basic types. Most common is splitting of the dense line of myelin sheaths to accommodate electron dense cytoplasm derived from the oligodendroglia. Less common are splits of the intraperiod line to form balloons or blisters that appear to contain fluid, the occurrence of sheaths with redundant myelin, and thick sheaths that are almost completely split so that one set of compact lamellae is surrounded by another set. But despite these alterations in the sheaths, few nerve fibers show axonal degeneration. To quantify the frequency of the age-related alterations in myelin, transversely sectioned nerve fibers from the splenium of the corpus callosum and from the vertical bundles of nerve fibers within area 46 were examined in electron photomicrographs. The material was taken from 19 monkeys, ranging between 5 and 35 years of age. It was found that the frequency of alterations in myelin sheaths from both locations correlates significantly with age. In area 46, the age-related alterations also significantly correlate (P < 0.001) with an overall assessment of impairment in cognition, i.e., the cognitive impairment index, displayed by individual monkeys. The correlation is also significant when only the old monkeys are considered as a group. A similar result was obtained previously in our examination of the effects of age on the myelin sheaths of nerve fibers in primary visual cortex (Peters et al. [2000] J Comp Neurol. 419:364-376). However, in the corpus callosum the myelin alterations correlate significantly with only one component of the cognitive impairment index, namely the delayed nonmatching to sample task with a 2-minute delay. It is proposed that age-related myelin alterations are ubiquitous and that the correlations between their frequency and impairments in

  11. [STRUCTURE OF HUMAN CORPUS CALLOSUM IN AFTER-DEATH STATE COMPARED TO INTRA-VITAM MRI IMAGES].

    PubMed

    Boiagina, O

    2016-05-01

    Our preliminary results suggest that the corpus callosum is composed of a certain number of stringy formations visualized on macroscopic and microscopic level that we proposed to call commissural funiculi. They are treated as subcallous units of the first order. The purpose of this research is to find out the form of the above-mentioned corpus callosum formations as being displayed on its sagittal profile as well as the extent to which they are displayed. The material used was male and female cerebrum of mature age people, who died for reasons not related to the pathology of the central nervous system. Cerebrum extracted from the skull after being washed was exposed to a two week fixation in 10% formalin solution. The sagittal plane slicer was used for brain dissection. Photo fixation of the medial surface of hemispheres was implemented with a digital camera. It was found out that the sagittal cut of the corpus callosum can be represented as a formation having segmental structure principle. Also, according to our observations, the trunk of the corpus callosum has distinct morphological features of bilateral asymmetry.

  12. Corpus Callosum Size, Reaction Time Speed and Variability in Mild Cognitive Disorders and in a Normative Sample

    ERIC Educational Resources Information Center

    Anstey, Kaarin J.; Mack, Holly A.; Christensen, Helen; Li, Shu-Chen; Reglade-Meslin, Chantal; Maller, Jerome; Kumar, Rajeev; Dear, Keith; Easteal, Simon; Sachdev, Perminder

    2007-01-01

    Intra-individual variability in reaction time increases with age and with neurological disorders, but the neural correlates of this increased variability remain uncertain. We hypothesized that both faster mean reaction time (RT) and less intra-individual RT variability would be associated with larger corpus callosum (CC) size in older adults, and…

  13. A case report: corpus callosum dysgenesis, microcephaly, infantile spasm, cleft lip-palate, exophthalmos and psychomotor retardation.

    PubMed

    Tütüncüoglu, S; Ozkinay, F; Genel, F; Uran, N; Ozgür, T

    1996-04-01

    In this report, a case with corpus callosum dysgenesis, infantile spasm, microcephaly, psychomotor retardation, exophthalmos, cleft lip-palate and abnormal EEG findings is presented. His parents are first-degree relatives. We could not fully match the findings of our patient with the criteria of any syndrome published to date.

  14. Neurotransmitter receptors and voltage-dependent Ca2+ channels encoded by mRNA from the adult corpus callosum.

    PubMed Central

    Matute, C; Miledi, R

    1993-01-01

    The presence of mRNAs encoding neurotransmitter receptors and voltage-gated channels in the adult human and bovine corpus callosum was investigated using Xenopus oocytes. Oocytes injected with mRNA extracted from the corpus callosum expressed functional receptors to glutamate, acetylcholine, and serotonin, and also voltage-operated Ca2+ channels, all with similar properties in the two species studied. Acetylcholine and serotonin elicited oscillatory Cl- currents due to activation of the inositol phosphate-Ca2+ receptor-channel coupling system. Glutamate and its analogs N-methyl-D-aspartate (NMDA), kainate, quisqualate, and alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) induced smooth currents. The non-NMDA responses showed a strong inward rectification at positive potentials and were potently blocked by 6,7-dinitroquinoxaline-2,3-dione, as observed for the AMPA/kainate glutamate receptors GLUR1 and GLUR3. Furthermore, in situ hybridization experiments showed that GLUR1 and GLUR3 mRNAs are present in corpus callosum cells that were labeled with antiserum to glial fibrillary acid protein and that, in primary cell cultures, had the morphology of type 2 astrocytes. These results indicate that glial cells in the adult corpus callosum possess mRNA encoding functional neurotransmitter receptors and Ca2+ channels. These molecules may provide a mechanism for glial-neuronal interactions. Images Fig. 1 Fig. 5 Fig. 6 Fig. 7 PMID:7682696

  15. Topographical organization of human corpus callosum: an fMRI mapping study.

    PubMed

    Fabri, Mara; Polonara, Gabriele; Mascioli, Giulia; Salvolini, Ugo; Manzoni, Tullio

    2011-01-25

    The concept of a topographical map of the corpus callosum (CC) has emerged from human lesion studies and from anatomical tracing investigations in other mammals. Over the last few years, a rising number of researchers have been reporting functional magnetic resonance imaging (fMRI) activation in white matter, particularly the CC. In this study, the scope for describing CC topography with fMRI was explored by evoking activation through simple sensory stimulation and motor tasks. We reviewed our published and unpublished fMRI data on the cortical representation of tactile, gustatory, and visual sensitivity and of motor activation, obtained in 36 volunteers. Activation foci were consistently detected in discrete CC regions: anterior (taste stimuli), central (motor tasks), central and posterior (tactile stimuli), and splenium (visual stimuli). These findings demonstrate that the functional topography of the CC can be explored with fMRI.

  16. Correlation between Corpus Callosum Sub-Segmental Area and Cognitive Processes in School-Age Children

    PubMed Central

    Moreno, Martha Beatriz; Concha, Luis; González-Santos, Leopoldo; Ortiz, Juan Jose; Barrios, Fernando Alejandro

    2014-01-01

    We assessed the relationship between structural characteristics (area) and microstructure (apparent diffusion coefficient; ADC) of the corpus callosum (CC) in 57 healthy children aged 7.0 to 9.1 years, with diverse cognitive and academic abilities as well as executive functions evaluated with a neuropsychological battery for children. The CC was manually delineated and sub-segmented into six regions, and their ADC and area were measured. There were no significant differences between genders in the callosal region area or in ADC. The CC area and ADC, mainly of anterior regions, correlated with different cognitive abilities for each gender. Our results suggest that the relationship between cognitive abilities and CC characteristics is different between girls and boys and between the anterior and posterior regions of the CC. Furthermore, these findings strenghten the idea that regardless of the different interhemispheric connectivity schemes per gender, the results of cognitive tasks are very similar for girls and boys throughout childhood. PMID:25170897

  17. Abnormality of the corpus callosum in coalmine gas explosion-related posttraumatic stress disorder.

    PubMed

    Zhang, Yang; Li, Huabing; Lang, Xu; Zhuo, Chuanjun; Qin, Wen; Zhang, Quan

    2015-01-01

    Abnormal corpus callosum (CC) has been reported in childhood trauma-related posttraumatic stress disorder (PTSD); however, the nature of white matter (WM) integrity alterations in the CC of young adult-onset PTSD patients is unknown. In this study, 14 victims of a coal mine gas explosion with PTSD and 23 matched coal miners without experiencing the coal mine explosion were enrolled. The differences in fractional anisotropy (FA) within 7 sub-regions of the CC were compared between the two groups. Compared to the controls, PTSD coal miners exhibited significantly reduced FA values in the anterior sub-regions of the CC (P < 0.05, Bonferroni-corrected), which mainly interconnect the bilateral frontal cortices. Our findings indicated that the anterior part of the CC was more severely impaired than the posterior part in young adult-onset PTSD, which suggested the patterns of CC impairment may depend on the developmental stage of the structure when the PTSD occurs.

  18. Properties of angiotensin II receptors in glial cells from the adult corpus callosum.

    PubMed Central

    Matute, C; Pulakat, L; Río, C; Valcárcel, C; Miledi, R

    1994-01-01

    The existence and the properties of angiotensin II receptors in the adult bovine and human corpus callosum (CC) were investigated by using Xenopus oocytes and primary glial cell cultures. In oocytes injected with CC mRNA, angiotensin II elicited oscillatory Cl- currents due to activation of the inositol phosphate/Ca(2+)-receptor-channel coupling system. The receptors expressed in oocytes and in CC cultures were pharmacologically similar to the AT1 receptor type as assayed by binding. Northern blot analysis and in situ hybridization studies in sections from CC and in glial cultures revealed that the receptors were molecularly related to the AT1 receptor and that they were present in astrocytes. In these cells, activation of the receptors with angiotensin II increased de novo DNA synthesis, promoted the release of aldosterone, and induced c-Fos expression. These findings indicate that CC astrocytes possess functional AT1 receptors that participate in various physiological processes. Images PMID:8170986

  19. Age effects in identifying and localising dichotic stimuli: a corpus callosum deficit?

    PubMed

    Gootjes, Liselotte; Van Strien, Jan W; Bouma, Anke

    2004-09-01

    In the present study, dichotic listening performance of 31 older adults was compared with performance of 25 younger adults under free and focused attention conditions. In addition to an age-related general decrease in performance, we observed in the focused attention condition increased asymmetry in the elderly group: the decrease of recall performance was stronger for the left ear (LE) then for the right ear (RE), while the increase of localisation errors were greater for the RE than for LE. Identifying and localising digits appear to be different process mediated predominantly by the left and right hemisphere, respectively. Since age-related reduced performance is strongest for the ear ipsilateral to the hemisphere dominant to that particular function, these finding may be ascribed to decline of corpus callosum functioning resulting in decrease interhemispheric interaction rather than to a selective decline of right hemisphere functions.

  20. The relationship between early life stress and microstructural integrity of the corpus callosum in a non-clinical population

    PubMed Central

    Paul, Robert; Henry, Lorrie; Grieve, Stuart M; Guilmette, Thomas J; Niaura, Raymond; Bryant, Richard; Bruce, Steven; Williams, Leanne M; Richard, Clark C; Cohen, Ronald A; Gordon, Evian

    2008-01-01

    Background Previous studies have examined the impact of early life stress (ELS) on the gross morphometry of brain regions, including the corpus callosum. However, studies have not examined the relationship between ELS and the microstructural integrity of the brain. Methods In the present study we evaluated this relationship in healthy non-clinical participants using diffusion tensor imaging (DTI) and self-reported history of ELS. Results Regression analyses revealed significant reductions in fractional anisotropy (FA) within the genu of the corpus callosum among those exposed to the greatest number of early life stressors, suggesting reduced microstructural integrity associated with increased ELS. These effects were most pronounced in the genu of the corpus callosum compared to the body and splenium, and were evident for females rather than males despite no differences in total ELS exposure between the sexes. In addition, a further comparison of those participants who were exposed to no ELS vs. three or more ELS events revealed lower FA in the genu of the corpus callosum among the ELS-exposed group, with trends of FA reduction in the body and the whole corpus callosum. By contrast, there were no relationships between ELS and volumetric analysis of the CC regions. The two group did not differ significantly on measures of current depression, stress or anxiety. Conclusion Our results reveal that greater exposure to ELS is associated with microstructural alterations in the white matter in the absence of significant volumetric changes. Importantly, our results indicate that exposure to ELS is associated with abnormalities on DTI despite the absence of clinically significant psychiatric symptoms. Future studies are needed to determine whether specific types of ELS are more likely to impact brain structure and function. PMID:18728817

  1. Truncated Cables1 causes agenesis of the corpus callosum in mice.

    PubMed

    Mizuno, Seiya; Tra, Dinh T H; Mizobuchi, Atsushi; Iseki, Hiroyoshi; Mizuno-Iijima, Saori; Kim, Jun-Dal; Ishida, Junji; Matsuda, Yoichi; Kunita, Satoshi; Fukamizu, Akiyoshi; Sugiyama, Fumihiro; Yagami, Ken-ichi

    2014-03-01

    Agenesis of the corpus callosum (ACC) is a congenital abnormality of the brain structure. More than 60 genes are known to be involved in corpus callosum development. However, the molecular mechanisms underlying ACC are not fully understood. Previously, we produced a novel transgenic mouse strain, TAS, carrying genes of the tetracycline-inducible expression system that are not involved in brain development, and inherited ACC was observed in the brains of all homozygous TAS mice. Although ACC was probably induced by transgene insertion mutation, the causative gene and the molecular mechanism of its pathogenesis remain unclear. Here, we first performed interphase three-color fluorescence in situ hybridization (FISH) analysis to determine the genomic insertion site. Transgenes were inserted into chromosome 18 ∼12.0 Mb from the centromere. Gene expression analysis and genomic PCR walking showed that the genomic region containing exon 4 of Cables1 was deleted by transgene insertion and the other exons of Cables1 were intact. The mutant allele was designated as Cables1(TAS). Interestingly, Cables1(TAS) mRNA consisted of exons 1-3 of Cables1 and part of the transgene that encoded a novel truncated Cables1 protein. Homozygous TAS mice exhibited mRNA expression of Cables1(TAS) in the fetal cerebrum, but not that of wild-type Cables1. To investigate whether a dominant negative effect of Cables1(TAS) or complete loss of function of Cables1 gives rise to ACC, we produced Cables1-null mutant mice. ACC was not observed in Cables1-null mutant mice, suggesting that a dominant negative effect of Cables1(TAS) impairs callosal formation. Moreover, ACC frequency in Cables1(+/TAS) mice was significantly lower than that in Cables1(-/TAS) mice, indicating that wild-type Cables1 interfered with the dominant negative effect of Cables1(TAS). This study indicated that truncated Cables1 causes ACC and wild-type Cables1 contributes to callosal formation.

  2. Learning and memory in individuals with agenesis of the corpus callosum.

    PubMed

    Paul, Lynn K; Erickson, Roger L; Hartman, Jo Ann; Brown, Warren S

    2016-06-01

    Damage to long white matter pathways in the cerebral cortex is known to affect memory capacity. However, the specific contribution of interhemispheric connectivity in memory functioning is only beginning to become understood. The present study examined verbal and visual memory processing in individuals with agenesis of the corpus callosum (AgCC) using the Wechsler Memory Scale-Third Edition (WMS-III; Wechsler, 1997b). Thirty participants with AgCC (FSIQ >78) were compared against 30 healthy age and IQ matched controls on auditory/verbal (Logical Memory, Verbal Paired Associates) and visual (Visual Reproduction, Faces) memory subtests. Performance was worse in AgCC than controls on immediate and delayed verbal recall for rote word pairs and on delayed recall of faces, as well as on percent recall for these tasks. Immediate recall for thematic information from stories was also worse in AgCC, but groups did not differ on memory for details from narratives or on recall for thematic information following a time delay. Groups also did not differ on memory for abstract figures or immediate recall of faces. On all subtests, individuals with AgCC had greater frequency of clinically significant impairments than predicted by the normal distribution. Results suggest less efficient overall verbal and visual learning and memory with relative weaknesses processing verbal pairs and delayed recall for faces. These findings suggest that the corpus callosum facilitates more efficient learning and recall for both verbal and visual information, that individuals with AgCC may benefit from receiving verbal information within semantic context, and that known deficits in facial processing in individuals with AgCC may contribute to their impairments in recall for faces.

  3. Androstenediol Reduces Demyelination-Induced Axonopathy in the Rat Corpus Callosum: Impact on Microglial Polarization

    PubMed Central

    Kalakh, Samah; Mouihate, Abdeslam

    2017-01-01

    Aims: We have previously shown that the neurosteroid androstenediol (ADIOL) promotes remyelination following gliotoxin-induced demyelination. However, the impact of this ADIOL on axonal recovery is not yet known. In the present study, we investigated the impact of ADIOL on axonal integrity following a focal demyelination in the corpus callosum. Methods: A 2 μl solution of either ethidium bromide (EB; 0.04%) or pyrogen-free saline were stereotaxically injected into the corpus callosum of Sprague Dawley rats. Each of these two rat groups was divided into two subgroups and received daily subcutaneous injections of either ADIOL (5 mg/kg) or vehicle. The brains were collected at 2, 7 and 14 days post-stereotaxic injection. Immunofluorescent staining was used to explore the impact of ADIOL on axonal integrity (neurofilament (NF)-M) and microglial activation (ionized calcium binding adapter molecule 1, Iba1). The inducible nitric oxide synthase (iNOS) and arginase-1 (arg-1), two major markers of microglial polarization towards the proinflammatory M1 and the regulatory M2 phenotypes respectively, were monitored using western blot. Results: ADIOL increased the density of NF fibers and decreased the extent of axonal damage in the vicinity of the demyelination lesion. ADIOL-induced decrease in axonal damage was manifested by decreased number of axonal spheroids at both 2 and 7 days post-demyelination insult. This reduced axonopathy was associated with decreased expression of iNOS and enhanced expression of arg-1 during the acute phase. Conclusion: These data strongly suggest that ADIOL reduces demyelination-induced axonal damage, likely by dampening the local inflammatory response in the white matter and shifting microglial polarization towards a reparative mode. PMID:28280460

  4. Disrupted developmental organization of the structural connectome in fetuses with corpus callosum agenesis.

    PubMed

    Jakab, András; Kasprian, Gregor; Schwartz, Ernst; Gruber, Gerlinde Maria; Mitter, Christian; Prayer, Daniela; Schöpf, Veronika; Langs, Georg

    2015-05-01

    Agenesis of the corpus callosum is a model disease for disrupted connectivity of the human brain, in which the pathological formation of interhemispheric fibers results in subtle to severe cognitive deficits. Postnatal studies suggest that the characteristic abnormal pathways in this pathology are compensatory structures that emerge via neural plasticity. We challenge this hypothesis and assume a globally different network organization of the structural interconnections already in the fetal acallosal brain. Twenty fetuses with isolated corpus callosum agenesis with or without associated malformations were enrolled and fiber connectivity among 90 brain regions was assessed using in utero diffusion tensor imaging and streamline tractography. Macroscopic scale connectomes were compared to 20 gestational age-matched normally developing fetuses with multiple granularity of network analysis. Gradually increasing connectivity strength and tract diffusion anisotropy during gestation were dominant in antero-posteriorly running paramedian and antero-laterally running aberrant pathways, and in short-range connections in the temporoparietal regions. In fetuses with associated abnormalities, more diffuse reduction of cortico-cortical and cortico-subcortical connectivity was observed than in cases with isolated callosal agenesis. The global organization of anatomical networks consisted of less segregated nodes in acallosal brains, and hubs of dense connectivity, such as the thalamus and cingulate cortex, showed reduced network centrality. Acallosal fetal brains show a globally altered connectivity network structure compared to normals. Besides the previously described Probst and sigmoid bundles, we revealed a prenatally differently organized macroconnectome, dominated by increased connectivity. These findings provide evidence that abnormal pathways are already present during at early stages of fetal brain development in the majority of cerebral white matter.

  5. The Role of Corpus Callosum Development in Functional Connectivity and Cognitive Processing

    PubMed Central

    Findlay, Anne M.; Honma, Susanne; Jeremy, Rita J.; Strominger, Zoe; Bukshpun, Polina; Wakahiro, Mari; Brown, Warren S.; Paul, Lynn K.; Barkovich, A. James; Mukherjee, Pratik; Nagarajan, Srikantan S.; Sherr, Elliott H.

    2012-01-01

    The corpus callosum is hypothesized to play a fundamental role in integrating information and mediating complex behaviors. Here, we demonstrate that lack of normal callosal development can lead to deficits in functional connectivity that are related to impairments in specific cognitive domains. We examined resting-state functional connectivity in individuals with agenesis of the corpus callosum (AgCC) and matched controls using magnetoencephalographic imaging (MEG-I) of coherence in the alpha (8–12 Hz), beta (12–30 Hz) and gamma (30–55 Hz) bands. Global connectivity (GC) was defined as synchronization between a region and the rest of the brain. In AgCC individuals, alpha band GC was significantly reduced in the dorsolateral pre-frontal (DLPFC), posterior parietal (PPC) and parieto-occipital cortices (PO). No significant differences in GC were seen in either the beta or gamma bands. We also explored the hypothesis that, in AgCC, this regional reduction in functional connectivity is explained primarily by a specific reduction in interhemispheric connectivity. However, our data suggest that reduced connectivity in these regions is driven by faulty coupling in both inter- and intrahemispheric connectivity. We also assessed whether the degree of connectivity correlated with behavioral performance, focusing on cognitive measures known to be impaired in AgCC individuals. Neuropsychological measures of verbal processing speed were significantly correlated with resting-state functional connectivity of the left medial and superior temporal lobe in AgCC participants. Connectivity of DLPFC correlated strongly with performance on the Tower of London in the AgCC cohort. These findings indicate that the abnormal callosal development produces salient but selective (alpha band only) resting-state functional connectivity disruptions that correlate with cognitive impairment. Understanding the relationship between impoverished functional connectivity and cognition is a key step

  6. In Vivo Longitudinal Monitoring of Changes in the Corpus Callosum Integrity During Disease Progression in a Mouse Model of Alzheimer's Disease.

    PubMed

    Kara, F; Höfling, C; Roßner, S; Schliebs, R; Van der Linden, A; Groot, H J M; Alia, A

    2015-01-01

    The corpus callosum is the largest commissural fiber connecting left and right hemisphere of the brain. Emerging evidence suggests that a variety of abnormalities detected in the microstructure of this white matter fiber can be an early event in Alzheimer's disease (AD) pathology. However, little is known about tissue characteristics of these abnormalities and how these abnormalities evolve during AD progression. In this study, we measured in vivo magnetic resonance transverse relaxation times (T2) to longitudinally monitor changes in tissue integrity and abnormalities related to myelination and demyelination processes in corpus callosum of AD mouse models. The most striking finding of our study was a significant elongation of T2 values in the corpus callosum at 10, 14, 16 and 18 months of age compared to age-matched wild-type mice. In contrast, the gray matter regions surrounding the corpus callosum, such as the cortex and hippocampus, showed a significant T2 decrease compared to wild-type mice. Histological analyses clearly revealed demyelination, gliosis and amyloid-plaque deposition in the corpus callosum. Our results suggest that demyelinating and inflammatory pathology may result in prolonged relaxation time during AD progression. To our knowledge, this is the first in vivo T2 study assessing the microstructural changes with age in the corpus callosum of the Tg2576 mouse model and it demonstrates the application of T2 measurement to noninvasively detect tissue integrity of the corpus callosum, which can be an early event in disease progression.

  7. Local-global interference is modulated by age, sex and anterior corpus callosum size

    PubMed Central

    Müller-Oehring, Eva M.; Schulte, Tilman; Raassi, Carla; Pfefferbaum, Adolf; Sullivan, Edith V.

    2007-01-01

    To identify attentional and neural mechanisms affecting global and local feature extraction, we devised a global-local hierarchical letter paradigm to test the hypothesis that aging reduces functional cerebral lateralization through corpus callosum (CC) degradation. Participants (37 men and women, 26–79 years) performed a task requiring global, local, or global+local attention and underwent structural MRI for CC measurement. Although reaction time (RT) slowed with age, all participants had faster RTs to local than global targets. This local precedence effect together with greater interference from incongruent local information and greater response conflict from local targets each correlated with older age and smaller callosal genu (anterior) areas. These findings support the hypothesis that the CC mediates lateralized local-global processes by inhibition of task-irrelevant information under selective attention conditions. Further, with advancing age smaller genu size leads to less robust inhibition, thereby reducing cerebral lateralization and permitting interference to influence processing. Sex was an additional modifier of interference, in that callosum-interference relationships were evident in women but not in men. Regardless of age, smaller splenium (posterior) areas correlated with less response facilitation from repetition priming of global targets in men, but with greater response facilitation from repetition priming of local targets in women. Our data indicate the following dissociation: Anterior callosal structure was associated with inhibitory processes (i.e., interference from incongruency and response conflict), which are vulnerable to the effects of age and sex, whereas posterior callosal structure was associated with facilitation processes from repetition priming dependent on sex and independent of age. PMID:17335783

  8. Acute infarct of the corpus callosum presenting as alien hand syndrome: evidence of diffusion weighted imaging and magnetic resonance angiography

    PubMed Central

    2011-01-01

    Background Infarcts of the corpus callosum are rare and have not been well documented previously. As for a variety of signs and symptoms presented, alien hand syndrome (AHS) can be easily overlooked. Case presentation In this report, we present a patient with a mixed types of AHS coexistence secondary to the corpus callosum infarction, including a motor type of AHS by intermanual conflict (callosal type AHS) and a sensory type of AHS by alien hand and left hemianesthesia (posterior AHS). Conclusions Our case may contribute to the early recognition of AHS and to explore the abnormal neural mechanism of AHS. To our knowledge, rare reports have ever documented such mixed AHS coexisting secondary to the callosal lesion, based on advanced neuroimaging methods as in our case. PMID:22067592

  9. Reduced fractional anisotropy in the anterior corpus callosum is associated with reduced speech fluency in persistent developmental stuttering.

    PubMed

    Civier, Oren; Kronfeld-Duenias, Vered; Amir, Ofer; Ezrati-Vinacour, Ruth; Ben-Shachar, Michal

    2015-04-01

    Developmental stuttering is a speech disorder that severely limits one's ability to communicate. White matter anomalies were reported in stuttering, but their functional significance is unclear. We analyzed the relation between white matter properties and speech fluency in adults who stutter (AWS). We used diffusion tensor imaging with tract-based spatial statistics, and examined group differences as well as correlations with behavioral fluency measures. We detected a region in the anterior corpus callosum with significantly lower fractional anisotropy in AWS relative to controls. Within the AWS group, reduced anisotropy in that region is associated with reduced fluency. A statistically significant interaction was found between group and age in two additional regions: the left Rolandic operculum and the left posterior corpus callosum. Our findings suggest that anterior callosal anomaly in stuttering may represent a maladaptive reduction in interhemispheric inhibition, possibly leading to a disadvantageous recruitment of right frontal cortex in speech production.

  10. Effects of Severing the Corpus Callosum on Electrical and BOLD Functional Connectivity and Spontaneous Dynamic Activity in the Rat Brain

    PubMed Central

    Magnuson, Matthew E.; Thompson, Garth J.; Pan, Wen-Ju

    2014-01-01

    Abstract Functional networks, defined by synchronous spontaneous blood oxygenation level-dependent (BOLD) oscillations between spatially distinct brain regions, appear to be essential to brain function and have been implicated in disease states, cognitive capacity, and sensing and motor processes. While the topographical extent and behavioral function of these networks has been extensively investigated, the neural functions that create and maintain these synchronizations remain mysterious. In this work callosotomized rodents are examined, providing a unique platform for evaluating the influence of structural connectivity via the corpus callosum on bilateral resting state functional connectivity. Two experimental groups were assessed, a full callosotomy group, in which the corpus callosum was completely sectioned, and a sham callosotomy group, in which the gray matter was sectioned but the corpus callosum remained intact. Results indicated a significant reduction in interhemispheric connectivity in the full callosotomy group as compared with the sham group in primary somatosensory cortex and caudate-putamen regions. Similarly, electrophysiology revealed significantly reduced bilateral correlation in band limited power. Bilateral gamma Band-limited power connectivity was most strongly affected by the full callosotomy procedure. This work represents a robust finding indicating the corpus callosum's influence on maintaining integrity in bilateral functional networks; further, functional magnetic resonance imaging (fMRI) and electrophysiological connectivity share a similar decrease in connectivity as a result of the callosotomy, suggesting that fMRI-measured functional connectivity reflects underlying changes in large-scale coordinated electrical activity. Finally, spatiotemporal dynamic patterns were evaluated in both groups; the full callosotomy rodents displayed a striking loss of bilaterally synchronous propagating waves of cortical activity. PMID:24117343

  11. Rapidly progressive dementia due to bilateral internal carotid artery occlusion with infarction of the total length of the corpus callosum.

    PubMed

    Rabinstein, Alejandro A; Romano, Jose G; Forteza, Alejandro M; Koch, Sebastian

    2004-04-01

    The authors report a patient with rapidly progressive cognitive decline due to bilateral internal carotid artery occlusion (ICAO) resulting in multiple pathologically proven cerebral infarctions including the entire length of the corpus callosum. The gradual evolution of the deficits was suggestive of hemodynamic ischemia. Bilateral ICAO should be considered in the differential diagnosis of patients with rapidly cognitive decline. Although ICAO commonly spares the splenium, complete callosal infarction is possible in the presence of bilateral ICAO.

  12. Reduced anterior corpus callosum white matter integrity is related to increased impulsivity and reduced discriminability in cocaine-dependent subjects: diffusion tensor imaging.

    PubMed

    Moeller, Frederick Gerard; Hasan, Khader M; Steinberg, Joel L; Kramer, Larry A; Dougherty, Donald M; Santos, Rafael M; Valdes, Ignacio; Swann, Alan C; Barratt, Ernest S; Narayana, Ponnada A

    2005-03-01

    Brain imaging studies find evidence of prefrontal cortical dysfunction in cocaine-dependent subjects. Similarly, cocaine-dependent subjects have problems with behaviors related to executive function and impulsivity. Since prefrontal cortical axonal tracts cross between hemispheres in the corpus callosum, it is possible that white matter integrity in the corpus callosum could also be diminished in cocaine-dependent subjects. The purpose of this study was to compare corpus callosum white matter integrity as measured by the fractional anisotropy (FA) on diffusion tensor imaging (DTI) between 18 cocaine-dependent subjects and 18 healthy controls. The Barratt Impulsiveness Scale (BIS-11) and a continuous performance test: the Immediate and Delayed Memory Task (IMT/DMT) were also collected. Results of the DTI showed significantly reduced FA in the genu and rostral body of the anterior corpus callosum in cocaine-dependent subjects compared to controls. Cocaine-dependent subjects also had significantly higher BIS-11 scores, greater impulsive (commission) errors, and reduced ability to discriminate target from catch stimuli (discriminability) on the IMT/DMT. Within cocaine dependent subjects there was a significant negative correlation between FA in the anterior corpus callosum and behavioral laboratory measured impulsivity, and there was a positive correlation between FA and discriminability. The finding that reduced integrity of anterior corpus callosum white matter in cocaine users is related to impaired impulse control and reduced ability to discriminate between target and catch stimuli is consistent with prior theories regarding frontal cortical involvement in impaired inhibitory control in cocaine-dependent subjects.

  13. Clinical Characterization, Genetics, and Long-Term Follow-up of a Large Cohort of Patients With Agenesis of the Corpus Callosum.

    PubMed

    Romaniello, Romina; Marelli, Susan; Giorda, Roberto; Bedeschi, Maria F; Bonaglia, Maria C; Arrigoni, Filippo; Triulzi, Fabio; Bassi, Maria T; Borgatti, Renato

    2017-01-01

    To gain a better understanding of the clinical and genetic features associated with agenesis of corpus callosum, we enrolled and characterized 162 patients with complete or partial agenesis of corpus callosum. Clinical and genetic protocols allowed us to categorize patients as syndromic subjects, affected by complex extra-brain malformations, and nonsyndromic subjects without any additional anomalies. We observed slight differences in sex ratio (56% males) and agenesis type (52% complete). Syndromic agenesis of corpus callosum subjects were prevalent (69%). We detected associated cerebral malformations in 48% of patients. Neuromotor impairment, cognitive and language disorders, and epilepsy were frequently present, regardless of the agenesis of corpus callosum subtype. Long-term follow-up allowed us to define additional indicators: syndromic agenesis of corpus callosum plus patients showed the most severe clinical features while isolated complete agenesis of corpus callosum patients had the mildest symptoms, although we observed intellectual disability (64%) and epilepsy (15%) in both categories. We achieved a definitive (clinical and/or genetic) diagnosis in 42% of subjects.

  14. A5 segment aneurysm of the anterior cerebral artery, imbedded into the body of the corpus callosum: A case report

    PubMed Central

    Sharafeddin, Fransua; Hafez, Ahmad; Lehecka, Martin; Raj, Rahul; Colasanti, Roberto; Rafiei, Ahmadreza; Choque, Joham; Jahromi, Behnam R.; Niemelä, Mika; Hernesniemi, Juha

    2017-01-01

    Background: The A5 segment aneurysms of the anterior cerebral artery are rare, approximately 0.5% of all intracranial aneurysms. They are small with a wide base located in the midline, with the domes mostly projecting upward or backward. Case Description: The authors describe a unique case of A5 segment aneurysm, with the dome embedded into the body of the corpus callosum. This 41-year-old female was admitted to the neurology department for possible multiple sclerosis investigation. Computed tomography angiogram (CTA) revealed a 4-mm right-sided pericallosal artery aneurysm, with rare configuration, which was caudally projected, embedded into the body of the corpus callosum. Considering the family history, patient underwent a prophylactic ligation surgery. The postoperative CT and CTA showed no complication and successful occlusion of the aneurysm with no ischemia or hemorrhage in the corpus callosum. Conclusion: To the best of our knowledge, this is the first case of an aneurysm with this configuration. Our rare case of A5 segment aneurysm demonstrates the importance of planning of the surgery, choosing the appropriate approach, and knowing the detailed anatomy of the region, as well as the necessity of microsurgical clipping of small unruptured AdistAs. PMID:28217397

  15. Age-Associated Alterations in Corpus Callosum White Matter Integrity in Bipolar Disorder Assessed Using Probabilistic Tractography

    PubMed Central

    Toteja, Nitin; Cokol, Perihan Guvenek; Ikuta, Toshikazu; Kafantaris, Vivian; Peters, Bart D.; Burdick, Katherine E.; John, Majnu; Malhotra, Anil K.; Szeszko, Philip R.

    2014-01-01

    Objectives Atypical age-associated changes in white matter integrity may play a role in the neurobiology of bipolar disorder, but no studies have examined the major white matter tracts using nonlinear statistical modeling across a wide age range in this disorder. The goal of this study was to identify possible deviations in the typical pattern of age-associated changes in white matter integrity in patients with bipolar disorder across the age range of 9 to 62 years. Methods Diffusion tensor imaging was performed in 57 (20M/37F) patients with a diagnosis of bipolar disorder and 57 (20M/37F) age- and sex-matched healthy volunteers. Mean diffusivity and fractional anisotropy were computed for the genu and splenium of the corpus callosum, two projection tracts, and five association tracts using probabilistic tractography. Results Overall, patients had lower fractional anisotropy and higher mean diffusivity compared to healthy volunteers across all tracts (while controlling for the effects of age and age2). In addition, there were greater age-associated increases in mean diffusivity in patients compared to healthy volunteers within the genu and splenium of the corpus callosum beginning in the second and third decades of life. Conclusions Our findings provide evidence for alterations in the typical pattern of white matter development in patients with bipolar disorder compared to healthy volunteers. Changes in white matter development within the corpus callosum may lead to altered inter-hemispheric communication that is considered integral to the neurobiology of the disorder. PMID:25532972

  16. Corpus callosum abnormalities, intellectual disability, speech impairment, and autism in patients with haploinsufficiency of ARID1B.

    PubMed

    Halgren, C; Kjaergaard, S; Bak, M; Hansen, C; El-Schich, Z; Anderson, C M; Henriksen, K F; Hjalgrim, H; Kirchhoff, M; Bijlsma, E K; Nielsen, M; den Hollander, N S; Ruivenkamp, C A L; Isidor, B; Le Caignec, C; Zannolli, R; Mucciolo, M; Renieri, A; Mari, F; Anderlid, B-M; Andrieux, J; Dieux, A; Tommerup, N; Bache, I

    2012-09-01

    Corpus callosum abnormalities, intellectual disability, speech impairment, and autism in patients with haploinsufficiency of ARID1B. Corpus callosum abnormalities are common brain malformations with a wide clinical spectrum ranging from severe intellectual disability to normal cognitive function. The etiology is expected to be genetic in as much as 30-50% of the cases, but the underlying genetic cause remains unknown in the majority of cases. By next-generation mate-pair sequencing we mapped the chromosomal breakpoints of a patient with a de novo balanced translocation, t(1;6)(p31;q25), agenesis of corpus callosum (CC), intellectual disability, severe speech impairment, and autism. The chromosome 6 breakpoint truncated ARID1B which was also truncated in a recently published translocation patient with a similar phenotype. Quantitative polymerase chain reaction (Q-PCR) data showed that a primer set proximal to the translocation showed increased expression of ARID1B, whereas primer sets spanning or distal to the translocation showed decreased expression in the patient relative to a non-related control set. Phenotype-genotype comparison of the translocation patient to seven unpublished patients with various sized deletions encompassing ARID1B confirms that haploinsufficiency of ARID1B is associated with CC abnormalities, intellectual disability, severe speech impairment, and autism. Our findings emphasize that ARID1B is important in human brain development and function in general, and in the development of CC and in speech development in particular.

  17. Contribution of posterior corpus callosum to the interhemispheric transfer of tactile information.

    PubMed

    Fabri, Mara; Del Pesce, Maria; Paggi, Aldo; Polonara, Gabriele; Bartolini, Marco; Salvolini, Ugo; Manzoni, Tullio

    2005-06-01

    Three total and three partial callosotomy patients underwent neuropsychological testing to evaluate interhemispheric transfer of tactile information. Tactile transfer is required to name objects presented to the left hand, to compare objects held in either hand, and to transfer topological information between hands. Tactile Naming, Same-Different Recognition, and Tactile Finger Localization Tests (intra- and intermanual tasks) were administered as specific tools. Results were compared with previous fMRI data from the same subjects and with the performance of a control group (20 age-matched subjects). Total callosotomy patients performed modestly: mean correct responses were 93% and 30% (right and left hand, respectively) in Tactile Naming; 68% in Same-Different Recognition; 84% and 76% (right and left hand stimulation, respectively) in intermanual Tactile Finger Localization, and 100% in the intramanual task. Partial callosotomy patients achieved 93-100% accuracy: all have an intact splenium, and one, and possibly all, also an intact posterior callosal body. Controls scored 99% in Tactile Naming, both hands, and Same-Different Recognition; 100% in intramanual Tactile Finger Localization; and 96% and 95%, with right and left hand stimulation, respectively, in the intermanual task. Differences between the two callosotomy groups were significant, as were those between total callosotomy patients and controls. The partial callosotomy group scored like the control subjects. Neuropsychological data agree with previous functional findings, further demonstrating that interhemispheric tactile transfer requires posterior corpus callosum integrity.

  18. Structural and functional brain rewiring clarifies preserved interhemispheric transfer in humans born without the corpus callosum

    PubMed Central

    Tovar-Moll, Fernanda; Monteiro, Myriam; Andrade, Juliana; Bramati, Ivanei E.; Vianna-Barbosa, Rodrigo; Marins, Theo; Rodrigues, Erika; Dantas, Natalia; Behrens, Timothy E. J.; de Oliveira-Souza, Ricardo; Moll, Jorge; Lent, Roberto

    2014-01-01

    Why do humans born without the corpus callosum, the major interhemispheric commissure, lack the disconnection syndrome classically described in callosotomized patients? This paradox was discovered by Nobel laureate Roger Sperry in 1968, and has remained unsolved since then. To tackle the hypothesis that alternative neural pathways could explain this puzzle, we investigated patients with callosal dysgenesis using structural and functional neuroimaging, as well as neuropsychological assessments. We identified two anomalous white-matter tracts by deterministic and probabilistic tractography, and provide supporting resting-state functional neuroimaging and neuropsychological evidence for their functional role in preserved interhemispheric transfer of complex tactile information, such as object recognition. These compensatory pathways connect the homotopic posterior parietal cortical areas (Brodmann areas 39 and surroundings) via the posterior and anterior commissures. We propose that anomalous brain circuitry of callosal dysgenesis is determined by long-distance plasticity, a set of hardware changes occurring in the developing brain after pathological interference. So far unknown, these pathological changes somehow divert growing axons away from the dorsal midline, creating alternative tracts through the ventral forebrain and the dorsal midbrain midline, with partial compensatory effects to the interhemispheric transfer of cortical function. PMID:24821757

  19. Congenital cataract, microphthalmia, hypoplasia of corpus callosum and hypogenitalism: report and review of Micro syndrome.

    PubMed

    Derbent, Murat; Agras, Pinar Isik; Gedik, Sansal; Oto, Sibel; Alehan, Füsun; Saatçi, Umit

    2004-07-30

    We report on a 7-month-old boy with Micro syndrome who was referred for assessment of mental-motor retardation and reduced vision with cataract. The characteristics of Micro syndrome are mental retardation, microcephaly, congenital cataract, microcornea, microphthalmia, agenesis/hypoplasia of the corpus callosum, and hypogenitalism. The differential diagnosis includes cerebro-oculo-facio-skeletal syndrome (COFS); a syndrome involving cataract, arthrogryposis, microcephaly, and kyphoscoliosis (CAMAK); a syndrome with cataract, microcephaly, failure to thrive, and kyphoscoliosis (CAMFAK); Martsolf syndrome; Neu-Laxova syndrome; Lenz microphthalmia syndrome; and Smith-Lemli-Opitz syndrome. Till date, no renal malformations have been reported in Micro syndrome. Our patient had fusion of the lower poles of the kidneys and his left kidney was ectopic. Ocular findings are the most reliable neonatal diagnostic signs of Micro syndrome. Minör anomalies in Micro syndrome may be subtle and therefore not of significant diagnostic value. Micro syndrome is an autosomal recessive trait. Till date, most reported cases have been in individuals of Muslim origin. In countries with high rates of consanguineous marriage, such as Turkey, it is important that physicians be able to recognize this syndrome. Micro syndrome should be considered in any infant with congenital cataract.

  20. Corpus Callosum and Neglect Syndrome: Clinical Findings After Meningioma Removal and Anatomical Review

    PubMed Central

    Gomes, David; Fonseca, Madalena; Garrotes, Maria; Lima, Maria Rita; Mendonça, Marta; Pereira, Mariana; Lourenço, Miguel; Oliveira, Edson; Lavrador, José Pedro

    2017-01-01

    Two types of neglect are described: hemispatial and motivational neglect syndromes. Neglect syndrome is a neurophysiologic condition characterized by a malfunction in one hemisphere of the brain, resulting in contralateral hemispatial neglect in the absence of sensory loss and the right parietal lobe lesion being the most common anatomical site leading to it. In motivational neglect, the less emotional input is considered from the neglected side where anterior cingulate cortex harbors the most frequent lesions. Nevertheless, there are reports of injuries in the corpus callosum (CC) causing hemispatial neglect syndrome, particularly located in the splenium. It is essential for a neurosurgeon to recognize this clinical syndrome as it can be either a primary manifestation of neurosurgical pathology (tumor, vascular lesion) or as a postoperative iatrogenic clinical finding. The authors report a postoperative hemispatial neglect syndrome after a falcotentorial meningioma removal that recovered 10 months after surgery and performs a clinical, anatomical, and histological review centered in CC as key agent in neglect syndrome. PMID:28149091

  1. Planimetry investigation of the corpus callosum in temporal lobe epilepsy patients

    PubMed Central

    Caglar, Veli; Alp, Selen I.; Demir, Berrin T.; Sener, Umit; Ozen, Oguz A.; Alp, Recep

    2016-01-01

    Objective: To evaluate the effects of temporal lobe epilepsy (TLE) on corpus callosum (CC) morphometry in patients with TLE. Methods: This retrospective study was conducted at the Faculty of Medicine, Tekirdag Namik Kemal University, Tekirdag, Turkey between November 2010 and December 2013. The epileptic syndrome diagnosis was based on International League Against Epilepsy criteria, and this study was conducted on the MRIs of 25 epilepsy patients and 25 control subjects. We classified the patients according to their duration of epilepsy <10 and ≥10 years. The projection area length (PAL) of the CC was also estimated. Total brain volumes (TBV) were measured on CT images. Results: The mean values of TBV for patients with TLE and the control group were not statistically different, but the CC PAL values were statistically different. The mean CC PAL values of under and over 25 years of age in patients with TLE were statistically different. The mean values of TBV of under and over 10 years duration of TLE were small statistically, but the CC PAL values were statistically different. Conclusion: The results indicate a clear influence of TLE on the structure of the CC rather than TBV. PMID:27094525

  2. The development of the corpus callosum in the healthy human brain.

    PubMed

    Luders, Eileen; Thompson, Paul M; Toga, Arthur W

    2010-08-18

    The corpus callosum changes structurally throughout life, but most dramatically during childhood and adolescence. Even so, existing studies of callosal development tend to use parcellation schemes that may not capture the complex spatial profile of anatomical changes. Thus, more detailed mapping of callosal growth processes is desirable to create a normative reference. This will help to relate and interpret other structural, functional, and behavioral measurements, both from healthy subjects and pediatric patients. We applied computational surface-based mesh-modeling methods to analyze callosal morphology at extremely high spatial resolution. We mapped callosal development and explored sex differences in a large and well matched sample of healthy children and adolescents (n = 190) aged 5-18 years. Except for the rostrum in females, callosal thickness increased across the whole surface, with sex- and region-specific rates of growth, and at times shrinkage. The temporally distinct changes in callosal thickness are likely to be a consequence of varying degrees of axonal myelination, redirection, and pruning. Alternating phases of callosal growth and shrinkage may reflect a permanent adjustment and fine-tuning of fibers connecting homologous cortical areas during childhood and adolescence. Our findings emphasize the importance of taking into account sex differences in future studies, as existing developmental effects might remain disguised (or biased toward the effect of the dominant sex in unbalanced statistical designs) when pooling male and female samples.

  3. Light microscopic identification of immature glial cells in semithin sections of the developing mouse corpus callosum.

    PubMed Central

    Sturrock, R R

    1976-01-01

    Four distinct types of glial cell were recognized in the corpus callosum of young postnatal mice: the early glioblast; the small glioblast; the large glioblast; and the young astrocyte. As well as these, mature microglia could be recognized from birth. In semithin, toluidine blue stained sections early glioblasts had large, fair to moderately stained nuclei, and a thin rim of pale cytoplasm; small glioblasts had small, dark nuclei and a rim of darkly stained cytoplasm; large glioblasts had moderately unevenly stained nuclei and a thin rim of moderately stained cytoplasm; and young astrocytes had fairly small nuclei, moderately stained cytoplasm, and one or more processes, which could usually be seen extending for 5 mum or more from the perikaryon. Differential glial counts using the criteria described above, in conjunction with electron microscopic analysis, suggested that early glioblasts gave rise to small glioblasts and large glioblasts; that small glioblasts gave rise directly to astrocytes, large glioblasts, oligodendrocytes and possibly microglia; that large glioblasts formed oligodendrocytes only, and might be immature light oligodendrocytes; and that part of the microglial population might arise from vascular pericytes. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 Fig. 10 Fig. 11 Fig. 12 Fig. 13 Fig. 14 PMID:795801

  4. A Case of a Newborn with Agenesis of the Corpus Callosum Complicated with Ocular Albinism

    PubMed Central

    Miki, Michiko; Miyamoto, Makiko; Mitsutsuji, Tatsuma; Watanabe, Hiroko; Shimizu, Kazuhiro; Matsuo, Junko; Tonari, Masahiro; Kida, Teruyo; Sugasawa, Jun; Ikeda, Tsunehiko

    2016-01-01

    Purpose To report a case of ocular albinism found in a newborn infant in whom agenesis of the corpus callosum (ACC) was indicated in utero. Case Report This study involved a female newborn who was delivered after a gestational period of 41 weeks. The patient was referred to the Obstetrics Department at Takatsuki Hospital, Takatsuki City, Japan, after the indication of ACC by magnetic resonance imaging (MRI) at a nearby clinic during the fetal period. At birth, the baby's weight was 2,590 g, and ACC and ventricular enlargement were found by cranial sonography and cranial MRI. While initial ophthalmic findings noted partial loss of pigmentation of the iris and hypopigmentation of broad areas of the fundus in both eyes, nystagmus was not observed. The patient's hair pigment was slightly diluted, and the color of her skin was slightly off-white. At 2 years after birth, obvious mental retardation was observed. With regard to other systemic findings, no apparent heart, kidney, or immune system abnormalities were found. Conclusion Although the patient in question is presently growing without any major systemic problems, it will be necessary in the future to pay attention to any changes in systemic and ophthalmic findings. PMID:27462254

  5. The corpus callosum in primates: processing speed of axons and the evolution of hemispheric asymmetry

    PubMed Central

    Phillips, Kimberley A.; Stimpson, Cheryl D.; Smaers, Jeroen B.; Raghanti, Mary Ann; Jacobs, Bob; Popratiloff, Anastas; Hof, Patrick R.; Sherwood, Chet C.

    2015-01-01

    Interhemispheric communication may be constrained as brain size increases because of transmission delays in action potentials over the length of axons. Although one might expect larger brains to have progressively thicker axons to compensate, spatial packing is a limiting factor. Axon size distributions within the primate corpus callosum (CC) may provide insights into how these demands affect conduction velocity. We used electron microscopy to explore phylogenetic variation in myelinated axon density and diameter of the CC from 14 different anthropoid primate species, including humans. The majority of axons were less than 1 µm in diameter across all species, indicating that conduction velocity for most interhemispheric communication is relatively constant regardless of brain size. The largest axons within the upper 95th percentile scaled with a progressively higher exponent than the median axons towards the posterior region of the CC. While brain mass among the primates in our analysis varied by 97-fold, estimates of the fastest cross-brain conduction times, as conveyed by axons at the 95th percentile, varied within a relatively narrow range between 3 and 9 ms across species, whereas cross-brain conduction times for the median axon diameters differed more substantially between 11 and 38 ms. Nonetheless, for both size classes of axons, an increase in diameter does not entirely compensate for the delay in interhemispheric transmission time that accompanies larger brain size. Such biophysical constraints on the processing speed of axons conveyed by the CC may play an important role in the evolution of hemispheric asymmetry. PMID:26511047

  6. Altered microstructure rather than morphology in the corpus callosum after lower limb amputation

    PubMed Central

    Li, Zhichao; Li, Chuanming; Fan, Lingzhong; Jiang, Guangyao; Wu, Jixiang; Jiang, Tianzi; Yin, Xuntao; Wang, Jian

    2017-01-01

    The corpus callosum (CC) has been implicated in the reorganization of the brain following amputation. However, it is unclear which regions of the CC are involved in this process. In this study, we explored the morphometric and microstructural changes in CC subregions in patients with unilateral lower limb amputation. Thirty-eight patients and 38 age- and gender-matched normal controls were included. The CC was divided into five regions, and the area, thickness and diffusion parameters of each region were investigated. While morphometric analysis showed no significant differences between the two groups, amputees showed significant higher values in axial diffusivity, radial diffusivity and mean diffusivity in region II of the CC, which connects the bilateral premotor and supplementary motor areas. In contrast, the mean fractional anisotropy value of the fibers generated by these cortical areas, as measured by tractography, was significantly smaller in amputees. These results demonstrate that the interhemispheric pathways contributing to motor coordination and imagery are reorganized in lower limb amputees. PMID:28303959

  7. Watershed-based segmentation of the corpus callosum in diffusion MRI

    NASA Astrophysics Data System (ADS)

    Freitas, Pedro; Rittner, Leticia; Appenzeller, Simone; Lapa, Aline; Lotufo, Roberto

    2012-02-01

    The corpus callosum (CC) is one of the most important white matter structures of the brain, interconnecting the two cerebral hemispheres, and is related to several neurodegenerative diseases. Since segmentation is usually the first step for studies in this structure, and manual volumetric segmentation is a very time-consuming task, it is important to have a robust automatic method for CC segmentation. We propose here an approach for fully automatic 3D segmentation of the CC in the magnetic resonance diffusion tensor images. The method uses the watershed transform and is performed on the fractional anisotropy (FA) map weighted by the projection of the principal eigenvector in the left-right direction. The section of the CC in the midsagittal slice is used as seed for the volumetric segmentation. Experiments with real diffusion MRI data showed that the proposed method is able to quickly segment the CC without any user intervention, with great results when compared to manual segmentation. Since it is simple, fast and does not require parameter settings, the proposed method is well suited for clinical applications.

  8. Gli3 controls corpus callosum formation by positioning midline guideposts during telencephalic patterning.

    PubMed

    Magnani, Dario; Hasenpusch-Theil, Kerstin; Benadiba, Carine; Yu, Tian; Basson, M Albert; Price, David J; Lebrand, Cécile; Theil, Thomas

    2014-01-01

    The corpus callosum (CC) represents the major forebrain commissure connecting the 2 cerebral hemispheres. Midline crossing of callosal axons is controlled by several glial and neuronal guideposts specifically located along the callosal path, but it remains unknown how these cells acquire their position. Here, we show that the Gli3 hypomorphic mouse mutant Polydactyly Nagoya (Pdn) displays agenesis of the CC and mislocation of the glial and neuronal guidepost cells. Using transplantation experiments, we demonstrate that agenesis of the CC is primarily caused by midline defects. These defects originate during telencephalic patterning and involve an up-regulation of Slit2 expression and altered Fgf and Wnt/β-catenin signaling. Mutations in sprouty1/2 which mimic the changes in these signaling pathways cause a disorganization of midline guideposts and CC agenesis. Moreover, a partial recovery of midline abnormalities in Pdn/Pdn;Slit2(-/-) embryos mutants confirms the functional importance of correct Slit2 expression levels for callosal development. Hence, Gli3 controlled restriction of Fgf and Wnt/β-catenin signaling and of Slit2 expression is crucial for positioning midline guideposts and callosal development.

  9. Splenium of Corpus Callosum: Patterns of Interhemispheric Interaction in Children and Adults

    PubMed Central

    Knyazeva, Maria G.

    2013-01-01

    The splenium of the corpus callosum connects the posterior cortices with fibers varying in size from thin late-myelinating axons in the anterior part, predominantly connecting parietal and temporal areas, to thick early-myelinating fibers in the posterior part, linking primary and secondary visual areas. In the adult human brain, the function of the splenium in a given area is defined by the specialization of the area and implemented via excitation and/or suppression of the contralateral homotopic and heterotopic areas at the same or different level of visual hierarchy. These mechanisms are facilitated by interhemispheric synchronization of oscillatory activity, also supported by the splenium. In postnatal ontogenesis, structural MRI reveals a protracted formation of the splenium during the first two decades of human life. In doing so, the slow myelination of the splenium correlates with the formation of interhemispheric excitatory influences in the extrastriate areas and the EEG synchronization, while the gradual increase of inhibitory effects in the striate cortex is linked to the local inhibitory circuitry. Reshaping interactions between interhemispherically distributed networks under various perceptual contexts allows sparsification of responses to superfluous information from the visual environment, leading to a reduction of metabolic and structural redundancy in a child's brain. PMID:23577273

  10. Dehydration-Induced Anorexia Reduces Astrocyte Density in the Rat Corpus Callosum

    PubMed Central

    Reyes-Haro, Daniel; Labrada-Moncada, Francisco Emmanuel; Miledi, Ricardo; Martínez-Torres, Ataúlfo

    2015-01-01

    Anorexia nervosa is an eating disorder associated with severe weight loss as a consequence of voluntary food intake avoidance. Animal models such as dehydration-induced anorexia (DIA) mimic core features of the disorder, including voluntary reduction in food intake, which compromises the supply of energy to the brain. Glial cells, the major population of nerve cells in the central nervous system, play a crucial role in supplying energy to the neurons. The corpus callosum (CC) is the largest white matter tract in mammals, and more than 99% of the cell somata correspond to glial cells in rodents. Whether glial cell density is altered in anorexia is unknown. Thus, the aim of this study was to estimate glial cell density in the three main regions of the CC (genu, body, and splenium) in a murine model of DIA. The astrocyte density was significantly reduced (~34%) for the DIA group in the body of the CC, whereas in the genu and the splenium no significant changes were observed. DIA and forced food restriction (FFR) also reduced the ratio of astrocytes to glial cells by 57.5% and 22%, respectively, in the body of CC. Thus, we conclude that DIA reduces astrocyte density only in the body of the rat CC. PMID:26090235

  11. Abnormal pathways in the genu of the corpus callosum in schizophrenia pathogenesis: a proteome study.

    PubMed

    Sivagnanasundaram, Sinthuja; Crossett, Ben; Dedova, Irina; Cordwell, Stuart; Matsumoto, Izuru

    2007-10-01

    Abnormalities within the corpus callosum (CC) have been identified in schizophrenia brains and are thought to affect inter-hemispheric communication, which in-turn is postulated to underlie some schizophrenia symptoms. Furthermore, hemisphere asymmetry of fractional anisotropy, detected by diffusion tensor imaging, left-higher-than-right- has been observed in normal individuals in the CC genu. This asymmetry is significantly reduced in the left CC genu of first-episode and chronic schizophrenia subjects. We examined the protein expression profile of the CC genu, including the profiles from the left and right hemisphere, in schizophrenia brains compared to controls using two-dimensional gel electrophoresis and mass spectrometry techniques. Proteins involved in cytoskeletal structure and function, neuroprotective function and energy metabolism were identified as differentially expressed, suggesting these proteins may underlie abnormal CC genu structure and function. Proteins in these functional categories also displayed different expression levels in the left CC genu compared to the right in both control and schizophrenia brains and therefore may be involved in normal CC asymmetry and reduced asymmetry in schizophrenia individuals. This initial pool of protein candidates and abnormal functional pathways opens up avenues for further investigation of molecular mechanisms involving the CC in schizophrenia pathogenesis and symptoms.

  12. Role of corpus callosum integrity in arm function differs based on motor severity after stroke.

    PubMed

    Stewart, Jill Campbell; Dewanjee, Pritha; Tran, George; Quinlan, Erin Burke; Dodakian, Lucy; McKenzie, Alison; See, Jill; Cramer, Steven C

    2017-01-01

    While the corpus callosum (CC) is important to normal sensorimotor function, its role in motor function after stroke is less well understood. This study examined the relationship between structural integrity of the motor and sensory sections of the CC, as reflected by fractional anisotropy (FA), and motor function in individuals with a range of motor impairment level due to stroke. Fifty-five individuals with chronic stroke (Fugl-Meyer motor score range 14 to 61) and 18 healthy controls underwent diffusion tensor imaging and a set of motor behavior tests. Mean FA from the motor and sensory regions of the CC and from corticospinal tract (CST) were extracted and relationships with behavioral measures evaluated. Across all participants, FA in both CC regions was significantly decreased after stroke (p < 0.001) and showed a significant, positive correlation with level of motor function. However, these relationships varied based on degree of motor impairment: in individuals with relatively less motor impairment (Fugl-Meyer motor score > 39), motor status correlated with FA in the CC but not the CST, while in individuals with relatively greater motor impairment (Fugl-Meyer motor score ≤ 39), motor status correlated with FA in the CST but not the CC. The role interhemispheric motor connections play in motor function after stroke may differ based on level of motor impairment. These findings emphasize the heterogeneity of stroke, and suggest that biomarkers and treatment approaches targeting separate subgroups may be warranted.

  13. Developmental malformation of the corpus callosum: a review of typical callosal development and examples of developmental disorders with callosal involvement.

    PubMed

    Paul, Lynn K

    2011-03-01

    This review provides an overview of the involvement of the corpus callosum (CC) in a variety of developmental disorders that are currently defined exclusively by genetics, developmental insult, and/or behavior. I begin with a general review of CC development, connectivity, and function, followed by discussion of the research methods typically utilized to study the callosum. The bulk of the review concentrates on specific developmental disorders, beginning with agenesis of the corpus callosum (AgCC)-the only condition diagnosed exclusively by callosal anatomy. This is followed by a review of several genetic disorders that commonly result in social impairments and/or psychopathology similar to AgCC (neurofibromatosis-1, Turner syndrome, 22q11.2 deletion syndrome, Williams yndrome, and fragile X) and two forms of prenatal injury (premature birth, fetal alcohol syndrome) known to impact callosal development. Finally, I examine callosal involvement in several common developmental disorders defined exclusively by behavioral patterns (developmental language delay, dyslexia, attention-deficit hyperactive disorder, autism spectrum disorders, and Tourette syndrome).

  14. Effects of sex chromosome dosage on corpus callosum morphology in supernumerary sex chromosome aneuploidies

    PubMed Central

    2014-01-01

    Background Supernumerary sex chromosome aneuploidies (sSCA) are characterized by the presence of one or more additional sex chromosomes in an individual’s karyotype; they affect around 1 in 400 individuals. Although there is high variability, each sSCA subtype has a characteristic set of cognitive and physical phenotypes. Here, we investigated the differences in the morphometry of the human corpus callosum (CC) between sex-matched controls 46,XY (N =99), 46,XX (N =93), and six unique sSCA karyotypes: 47,XYY (N =29), 47,XXY (N =58), 48,XXYY (N =20), 47,XXX (N =30), 48,XXXY (N =5), and 49,XXXXY (N =6). Methods We investigated CC morphometry using local and global area, local curvature of the CC boundary, and between-landmark distance analysis (BLDA). We hypothesized that CC morphometry would vary differentially along a proposed spectrum of Y:X chromosome ratio with supernumerary Y karyotypes having the largest CC areas and supernumerary X karyotypes having significantly smaller CC areas. To investigate this, we defined an sSCA spectrum based on a descending Y:X karyotype ratio: 47,XYY, 46,XY, 48,XXYY, 47,XXY, 48,XXXY, 49,XXXXY, 46,XX, 47,XXX. We similarly explored the effects of both X and Y chromosome numbers within sex. Results of shape-based metrics were analyzed using permutation tests consisting of 5,000 iterations. Results Several subregional areas, local curvature, and BLDs differed between groups. Moderate associations were found between area and curvature in relation to the spectrum and X and Y chromosome counts. BLD was strongly associated with X chromosome count in both male and female groups. Conclusions Our results suggest that X- and Y-linked genes have differential effects on CC morphometry. To our knowledge, this is the first study to compare CC morphometry across these extremely rare groups. PMID:25780557

  15. Neurons in the corpus callosum of the cat during postnatal development.

    PubMed

    Riederer, Beat M; Berbel, Pere; Innocenti, Giorgio M

    2004-04-01

    The corpus callosum (CC) is a major telencephalic commissure containing mainly cortico-cortical axons and glial cells. We have identified neurons in the CC of the cat and quantified their number at different postnatal ages. An antibody against microtubule-associated protein 2 was used as a marker of neurons. Immunocytochemical double-labelling with neuron-specific enolase or gamma-aminobutyric acid antibodies in the absence of glial fibrillary acidic protein positivity confirmed the neuronal phenotype of these cells. CC neurons were also stained with anti-calbindin and anti-calretinin antibodies, typical for interneurons, and with an anti-neurofilament antibody, which in neocortex detects pyramidal neurons. Together, these findings suggest that the CC contains a mixed population of neuronal types. The quantification was corrected for double counting of adjacent sections and volume changes during CC development. Our data show that CC neurons are numerous early postnatally, and their number decreases with age. At birth, about 570 neurons are found within the CC boundaries and their number drops to about 200 in the adult. The distribution of the neurons within the CC also changes in development. Initially, many neurons are found throughout the CC, while at later ages they become restricted to the boundaries of the CC, and in the adult to the rostrum of the CC close to the septum pellucidum or to the indusium griseum. Although origin and function of transient CC neurons in development and in adulthood remain unknown, they are likely to be interstitial neurons. Some of them have well-developed and differentiated processes and resemble pyramidal cells or interneurons. An axon-guiding function during the early postnatal period can not be excluded.

  16. Neuropeptide Y immunoreactive axons in the corpus callosum of the cat during postnatal development.

    PubMed

    Ding, S L; Elberger, A J

    1994-07-01

    Many immunocytochemical studies have identified different types of neurotransmitters localized in the corpus callosum (CC) axons in the adult mammal. Few studies have looked at the development of different neurochemically identified CC systems. Previous studies on the development of cat CC axons have indicated that a large number of transitory CC axons project to the cortex during early postnatal development. The present study focuses on the development of one neurochemically identified group of CC axons in the cat, labeled with an antibody against neuropeptide Y (NPY), to determine if this group participates in transitory CC axonal growth. Cats at specified ages from birth to adulthood were studied with a routine method of immunocytochemistry for antiserum to NPY. NPY-immunoreactive (ir) CC axons were detected at all stages examined, from newborn to adult; the peak density occurred during postnatal weeks (PNW) 3-4. During PNW 1-2, the density of NPY-ir CC axons increased gradually; some NPY-ir axons at this age had growth cones located within the CC bundle between the cerebral hemispheres. The density of the NPY-ir CC axons decreased gradually during PNW 5-7, and from PNW 8 to maturity only a few NPY-ir CC axons were observed. These results indicate that at least two types of NPY-ir CC axons (i.e., transitory and permanent) exist during development, and that most of these axons are eliminated or only express NPY-ir for a short period during development. The results also indicate that neurochemical subsets of CC axons participate in the extensive transitory growth observed by means of the membrane tracer DiI but they may follow unique developmental timetables.

  17. Effect of registration on corpus callosum population differences found with DBM analysis

    NASA Astrophysics Data System (ADS)

    Han, Zhaoying; Thornton-Wells, Tricia A.; Gore, John C.; Dawant, Benoit M.

    2011-03-01

    Deformation Based Morphometry (DBM) is a relatively new method used for characterizing anatomical differences among populations. DBM is based on the analysis of the deformation fields generated by non-rigid registration algorithms, which warp the individual volumes to one standard coordinate system. Although several studies have compared non-rigid registration algorithms for segmentation tasks, few studies have compared the effect of the registration algorithm on population differences that may be uncovered through DBM. In this study, we compared DBM results obtained with five well established non-rigid registration algorithms on the corpus callosum (CC) in thirteen subjects with Williams Syndrome (WS) and thirteen Normal Control (NC) subjects. The five non-rigid registration algorithms include: (1) The Adaptive Basis Algorithm (ABA); (2) Image Registration Toolkit (IRTK); (3) FSL Nonlinear Image Registration Tool (FSL); (4) Automatic Registration Tools (ART); and (5) the normalization algorithm available in SPM8. For each algorithm, the 3D deformation fields from all subjects to the atlas were obtained and used to calculate the Jacobian determinant (JAC) at each voxel in the mid-sagittal slice of the CC. The mean JAC maps for each group were compared quantitatively across different nonrigid registration algorithms. An ANOVA test performed on the means of the JAC over the Genu and the Splenium ROIs shows the JAC differences between nonrigid registration algorithms are statistically significant over the Genu for both groups and over the Splenium for the NC group. These results suggest that it is important to consider the effect of registration when using DBM to compute morphological differences in populations.

  18. Arteriovenous malformations of the corpus callosum: Pooled analysis and systematic review of literature

    PubMed Central

    Pabaney, Aqueel H.; Ali, Rushna; Kole, Maximillian; Malik, Ghaus M.

    2016-01-01

    Background: Arteriovenous malformations (AVMs) of the corpus callosum (CC) are rare entities. We performed a systematic review of the available literature to better define the natural history, patient characteristics, and treatment options for these lesions. Methods: A MEDLINE, Google Scholar, and The Cochrane Library search were performed for studies published through June 2015. Data from all eligible studies were used to examine epidemiology, natural history, clinical features, treatment strategies, and outcomes of patients with CC-AVMs. A systematic review and pooled analysis of the literature were performed. Results: Our search yielded 37 reports and 230 patients. Mean age at presentation was 26.8 years (±13.12 years). AVMs were most commonly located in the splenium (43%), followed by the body (31%), and then the genu (23%) of the CC. A Spetzler-Martin grade of III was the most common (37%). One hundred eighty-seven (81.3%) patients presented with hemorrhage, 91 (40%) underwent microsurgical excision, and 87 (38%) underwent endovascular embolization. Radiosurgery was performed on 57 (25%) patients. Complete obliteration of the AVM was achieved in 102 (48.1%) patients and approximately twice as often when microsurgery was performed alone or in combination with other treatment modalities (94% vs. 49%; P < 0.001). Mean modified Rankin Scale (mRS) at presentation was 1.54 and mean mRS at last follow-up was 1.31. This difference was not statistically significant (P = 0.35). Conclusion: We present an analysis of the pooled data in the form of a systematic review focusing on management of CC-AVMs. This review aims to provide a valuable tool to aid in decision making when dealing with this particular subtype of AVM. PMID:27127713

  19. Social communication in young children with traumatic brain injury: relations with corpus callosum morphometry.

    PubMed

    Ewing-Cobbs, Linda; Prasad, Mary R; Swank, Paul; Kramer, Larry; Mendez, Donna; Treble, Amery; Payne, Christa; Bachevalier, Jocelyne

    2012-05-01

    The purpose of the present investigation was to characterize the relations of specific social communication behaviors, including joint attention, gestures, and verbalization, with surface area of midsagittal corpus callosum (CC) subregions in children who sustained traumatic brain injury (TBI) before 7 years of age. Participants sustained mild (n=10) or moderate-severe (n=26) noninflicted TBI. The mean age at injury was 33.6 months; mean age at MRI was 44.4 months. The CC was divided into seven subregions. Relative to young children with mild TBI, those with moderate-severe TBI had smaller surface area of the isthmus. A semi-structured sequence of social interactions between the child and an examiner was videotaped and coded for specific social initiation and response behaviors. Social responses were similar across severity groups. Even though the complexity of their language was similar, children with moderate-severe TBI used more gestures than those with mild TBI to initiate social overtures; this may indicate a developmental lag or deficit as the use of gestural communication typically diminishes after age 2. After controlling for age at scan and for total brain volume, the correlation of social interaction response and initiation scores with the midsagittal surface area of the CC regions was examined. For the total group, responding to a social overture using joint attention was significantly and positively correlated with surface area of all regions, except the rostrum. Initiating joint attention was specifically and negatively correlated with surface area of the anterior midbody. Use of gestures to initiate a social interaction correlated significantly and positively with surface area of the anterior and posterior midbody. Social response and initiation behaviors were selectively related to regional callosal surface areas in young children with TBI. Specific brainbehavior relations indicate early regional specialization of anterior and posterior CC for social

  20. N-Methyl-D-Aspartate Receptor-Mediated Axonal Injury in Adult Rat Corpus Callosum

    PubMed Central

    Zhang, Jingdong; Liu, Jianuo; Fox, Howard S.; Xiong, Huangui

    2013-01-01

    Damage to white matter such as corpus callosum (CC) is a pathological characteristic in many brain disorders. Glutamate (Glut) excitotoxicity through AMPA receptors on oligodendrocyte (OL) was previously considered as a mechanism for white matter damage. Recent studies have shown that N-methyl-D-aspartate receptors (NMDARs) are expressed on myelin sheath of neonatal rat OL processes and that activation of these receptors mediated demyelization. Whether NMDARs are expressed in the adult CC and are involved in excitotoxic axonal injury remains to be determined. In this study, we demonstrate the presence of NMDARs in the adult rat CC and their distributions in myelinated nerve fibers and OL somata by means of immunocytochemical staining and Western blot. Incubation of the CC slices with Glut or NMDA induced axonal injury as revealed by analyzing amplitude of CC fiber compound action potentials (CAPs) and input–output response. Both Glut and NMDA decreased the CAP amplitude and input–output responses, suggesting an involvement of NMDARs in Glut- and NMDA-induced axonal injury. The involvement of NMDAR in Glut-induced axonal injury was further assayed by detection of β-amyloid precursor protein (β-APP) in the CC axonal fibers. Treatment of the CC slices with Glut resulted in β-APP accumulation in the CC fibers as detected by Western blot, reflecting an impairment of axonal transport function. This injurious effect of Glut on CC axonal transport was significantly blocked by MK801. Taken together, these results show that NMDARs are expressed in the adult CC and are involved in excitotoxic activity in adult CC slices in vitro. PMID:23161705

  1. Clinical utility of corpus callosum measurements in head sonograms of preterm infants: a cohort study

    PubMed Central

    Perenyi, Agnes; Amodio, John; Katz, Joanne S; Stefanov, Dimitre G

    2013-01-01

    Objective To assess the clinical usefulness of measurement of corpus callosum (CC) size in head ultrasound (HUS) to predict short-term neurodevelopmental (ND) outcomes in preterm infants. We hypothesised that including CC measurements in routine HUS will be an additional tool for early identification of infants at risk of adverse short-term ND outcome, over and above the predictive power of perinatal morbidities. Design Retrospective cohort study. Setting Level III neonatal intensive care unit (NICU) and outpatient NICU follow-up clinic of an academic medical centre in New York City. Participants 929 HUS of 502 infants with gestational age of 23–36 weeks in African-American infants were initially studied. Exclusion criteria included those who died, had gross abnormalities in HUS, infants with race other than African-American, infants with suboptimal quality of HUS, late preterm infants and infants who did not participate in ND follow-up. A total of 173 infants completed the study. Interventions CC size (length and thickness) was measured in a subset of 87 infants who had routine HUS between 23 and 29 weeks (0–6 postnatal weeks). Relevant clinical variables were collected from chart reviews. ND assessments were completed in outpatient follow-up clinics. A statistical model was developed to assess the clinical utility and possible predictive value of CC measurements for adverse short-term ND outcome, while adjusting for perinatal morbidities. Primary and secondary outcome measures CC size and ND status. Results Measurements of CC size did not add substantial predictive power to predict short-term ND outcome beyond the information provided by the presence of morbidities related to prematurity. Conclusions No association was found between morbidities related to prematurity and short-term ND outcome and CC size in preterm infants. CC measurements in HUS early in life did not have an additional value in predicting short-term ND outcome, therefore did not seem to

  2. Influence of Corpus Callosum Damage on Cognition and Physical Disability in Multiple Sclerosis: A Multimodal Study

    PubMed Central

    Llufriu, Sara; Blanco, Yolanda; Martinez-Heras, Eloy; Casanova-Molla, Jordi; Gabilondo, Iñigo; Sepulveda, Maria; Falcon, Carles; Berenguer, Joan; Bargallo, Nuria; Villoslada, Pablo; Graus, Francesc; Valls-Sole, Josep; Saiz, Albert

    2012-01-01

    Background Corpus callosum (CC) is a common target for multiple sclerosis (MS) pathology. We investigated the influence of CC damage on physical disability and cognitive dysfunction using a multimodal approach. Methods Twenty-one relapsing-remitting MS patients and 13 healthy controls underwent structural MRI and diffusion tensor of the CC (fractional anisotropy; mean diffusivity, MD; radial diffusivity, RD; axial diffusivity). Interhemisferic transfer of motor inhibition was assessed by recording the ipsilateral silent period (iSP) to transcranial magnetic stimulation. We evaluated cognitive function using the Brief Repeatable Battery and physical disability using the Expanded Disability Status Scale (EDSS) and the MS Functional Composite (MSFC) z-score. Results The iSP latency correlated with physical disability scores (r ranged from 0.596 to 0.657, P values from 0.004 to 0.001), and with results of visual memory (r = −0.645, P = 0.002), processing speed (r = −0.51, P = 0.018) and executive cognitive domain tests (r = −0.452, P = 0.039). The area of the rostrum correlated with the EDSS (r = −0.442, P = 0.045). MD and RD correlated with cognitive performance, mainly with results of visual and verbal memory tests (r ranged from −0.446 to −0.546, P values from 0.048 to 0.011). The iSP latency correlated with CC area (r = −0.345, P = 0.049), volume (r = −0.401, P = 0.002), MD (r = 0.404, P = 0.002) and RD (r = 0.415, P = 0.016). Conclusions We found evidence for structural and microstructural CC abnormalities associated with impairment of motor callosal inhibitory conduction in MS. CC damage may contribute to cognitive dysfunction and in less extent to physical disability likely through a disconnection mechanism. PMID:22606347

  3. Low-cost, rapidly-developed, 3D printed in vitro corpus callosum model for mucopolysaccharidosis type I

    PubMed Central

    Tabet, Anthony; Gardner, Matthew; Swanson, Sebastian; Crump, Sydney; McMeekin, Austin; Gong, Diana; Tabet, Rebecca; Hacker, Benjamin; Nestrasil, Igor

    2017-01-01

    The rising prevalence of high throughput screening and the general inability of (1) two dimensional (2D) cell culture and (2) in vitro release studies to predict in vivo neurobiological and pharmacokinetic responses in humans has led to greater interest in more realistic three dimensional (3D) benchtop platforms. Advantages of 3D human cell culture over its 2D analogue, or even animal models, include taking the effects of microgeometry and long-range topological features into consideration. In the era of personalized medicine, it has become increasingly valuable to screen candidate molecules and synergistic therapeutics at a patient-specific level, in particular for diseases that manifest in highly variable ways. The lack of established standards and the relatively arbitrary choice of probing conditions has limited in vitro drug release to a largely qualitative assessment as opposed to a predictive, quantitative measure of pharmacokinetics and pharmacodynamics in tissue. Here we report the methods used in the rapid, low-cost development of a 3D model of a mucopolysaccharidosis type I patient’s corpus callosum, which may be used for cell culture and drug release. The CAD model is developed from in vivo brain MRI tracing of the corpus callosum using open-source software, printed with poly (lactic-acid) on a Makerbot Replicator 5X, UV-sterilized, and coated with poly (lysine) for cellular adhesion. Adaptations of material and 3D printer for expanded applications are also discussed. PMID:28357042

  4. Connectivity and the corpus callosum in autism spectrum conditions: insights from comparison of autism and callosal agenesis.

    PubMed

    Booth, Rhonda; Wallace, Gregory L; Happé, Francesca

    2011-01-01

    Neural models of autism spectrum disorders (ASDs) have moved, in recent years, from a lesion model to a focus on abnormal connectivity. In this chapter, we review this work and summarize findings from our recent research comparing autism and agenesis of the corpus callosum (AgCC). We discuss our findings in the context of the "fractionable triad" account and highlight three main points. First, the social aspects of autism can be found in isolation, not accompanied by the nonsocial features of this disorder, supporting a view of autism as a "compound," rather than "monolithic," condition. Second, many young people with callosal agenesis show theory of mind- and emotion-processing deficits akin to those seen in autism. Diagnostic overshadowing may mean these people do not receive interventions that have proven beneficial in ASD. Last, study of AgCC shows that it is possible, in some cases, to develop good social cognitive skills in the absence of the corpus callosum, presenting a challenge to future connectivity models of autism.

  5. A T1 and DTI fused 3D corpus callosum analysis in pre- vs. post-season contact sports players

    NASA Astrophysics Data System (ADS)

    Lao, Yi; Law, Meng; Shi, Jie; Gajawelli, Niharika; Haas, Lauren; Wang, Yalin; Leporé, Natasha

    2015-01-01

    Sports related traumatic brain injury (TBI) is a worldwide public health issue, and damage to the corpus callosum (CC) has been considered as an important indicator of TBI. However, contact sports players suffer repeated hits to the head during the course of a season even in the absence of diagnosed concussion, and less is known about their effect on callosal anatomy. In addition, T1-weighted and diffusion tensor brain magnetic resonance images (DTI) have been analyzed separately, but a joint analysis of both types of data may increase statistical power and give a more complete understanding of anatomical correlates of subclinical concussions in these athletes. Here, for the first time, we fuse T1 surface-based morphometry and a new DTI analysis on 3D surface representations of the CCs into a single statistical analysis on these subjects. Our new combined method successfully increases detection power in detecting differences between pre- vs. post-season contact sports players. Alterations are found in the ventral genu, isthmus, and splenium of CC. Our findings may inform future health assessments in contact sports players. The new method here is also the first truly multimodal diffusion and T1-weighted analysis of the CC, and may be useful to detect anatomical changes in the corpus callosum in other multimodal datasets.

  6. Polymicrogyria, Large Corpus Callosum and Psychomotor Retardation in Four-Year-Old Girl: Potential Association Based on MR Findings. A Case Report and Literature Review.

    PubMed

    Budai, Caterina; Moscato, Giulia; Patruno, Francesco; Leonardi, Marco; Maffei, Monica

    2014-10-01

    SUMMARY - We describe a child from consanguineous parents presenting mega corpus callosum (MegaCC), polymicrogyria, psychomotor retardation with swallowing difficulties and language impairment perhaps linked to the syndrome of megalencephaly-polymicrogyria-mega corpus callosum (MEG-PMG-MegaCC). Reviewing the literature, we speculate that MegaCC, psychomotor retardation and anomalies in cortical migration are the three pathognomonic features. The presence of additional possibly associated anomalies such as megalencephaly, indicates that the spectrum of linked malformations with this rare syndrome is broad and yet to be defined.

  7. Abnormal increase of neuronal precursor cells and exacerbated neuroinflammation in the corpus callosum in murine model of systemic lupus erythematosus

    PubMed Central

    Leung, Joseph Wai-Hin; Lau, Benson Wui-Man; Chan, Vera Sau-Fong; Lau, Chak-Sing; So, Kwok-Fai

    2016-01-01

    Purpose: Systemic Lupus Erythematosus (SLE) is an autoimmune disease which is characterised by elevated levels of autoantibodies and cytokines in the body. Via alteration of the regulation of inflammation, damage to different organ systems, including the central nervous system (CNS), was found in SLE patients. Patients diagnosed with SLE were reported to suffer from different kinds of psychiatric signs and symptoms. As neurogenesis has been suggested to be a potential key player of psychiatric symptoms and emotional behavior disturbances, this study aims to investigate whether neurogenesis is altered in an animal model of SLE. Also, neuroinflammation was studied. Methods: Female NZB/W F1 mice were used as an animal model of SLE. Animals were divided into two groups: 1. pre-diseased mice (lupus-prone NZB/W F1 female mice, age 10–15 weeks, negative for proteinuria and with basal levels of serum anti-dsDNA autoantibodies) and 2. diseased mice (NZB/W F1 female mice, > 25 weeks of age, with elevated serum levels of anti-dsDNA autoantibodies and with persistent proteinuria of > 3 mg/ml for more than 2 weeks). Comparisons of the levels of neurogenesis and neuroinflammtion between two groups of mice were studied by the immunohistochemistry. Results: After the onset of SLE symptoms, a reduction of neurogenesis in the hippocampus was found, while there was a dramatic increase of doublecortin (DCX+) neuronal precursor cells in the corpus callosum (CC) and in the subventricular zone (SVZ). Meanwhile, exacerbated inflammation was present in the corpus callosum of the diseased mice, which was suggested by the increased number of GFAP+ cells and IBA-1+ cells. Conclusions: To the best of our knowledge, this is the first study showing an increase of neuronal precursor cells in the corpus callosum of the female NZB/W F1 mice. The present study suggests a coincidence but not a causal relationship between neurogenesis and neuroinflammation. The present results have

  8. Segmented corpus callosum diffusivity correlates with the Expanded Disability Status Scale score in the early stages of relapsing-remitting multiple sclerosis

    PubMed Central

    de Medeiros Rimkus, Carolina; de Faria Junqueira, Thiago; Callegaro, Dagoberto; Otaduy, Maria Concepción García; da Costa Leite, Claudia

    2013-01-01

    OBJECTIVE: The aim of this study was to characterize the microscopic damage to the corpus callosum in relapsing-remitting multiple sclerosis (RRMS) with diffusion tensor imaging and to investigate the correlation of this damage with disability. The diffusion tensor imaging parameters of fractional anisotropy and mean diffusivity provide information about the integrity of cell membranes, offering two more specific indices, namely the axial and radial diffusivities, which are useful for discriminating axon loss from demyelination. METHOD: Brain magnetic resonance imaging exams of 30 relapsing-remitting multiple sclerosis patients and 30 age- and sex-matched healthy controls were acquired in a 3T scanner. The axial diffusivities, radial diffusivities, fractional anisotropy, and mean diffusivity of five segments of the corpus callosum, correlated to the Expanded Disability Status Scale score, were obtained. RESULTS: All corpus callosum segments showed increased radial diffusivities and mean diffusivity, as well as decreased fractional anisotropy, in the relapsing-remitting multiple sclerosis group. The axial diffusivity was increased in the posterior midbody and splenium. The Expanded Disability Status Scale scores correlated more strongly with axial diffusivities and mean diffusivity, with an isolated correlation with radial diffusivities in the posterior midbody of the corpus callosum. There was no significant correlation with lesion loads. CONCLUSION: Neurological dysfunction in relapsing-remitting multiple sclerosis can be influenced by commissural disconnection, and the diffusion indices of diffusion tensor imaging are potential biomarkers of disability that can be assessed during follow-up. PMID:24037007

  9. Abnormal Corpus Callosum Connectivity, Socio-Communicative Deficits, and Motor Deficits in Children with Autism Spectrum Disorder: A Diffusion Tensor Imaging Study

    ERIC Educational Resources Information Center

    Hanaie, Ryuzo; Mohri, Ikuko; Kagitani-Shimono, Kuriko; Tachibana, Masaya; Matsuzaki, Junko; Watanabe, Yoshiyuki; Fujita, Norihiko; Taniike, Masako

    2014-01-01

    In addition to social and communicative deficits, many studies have reported motor deficits in autism spectrum disorder (ASD). This study investigated the macro and microstructural properties of the corpus callosum (CC) of 18 children with ASD and 12 typically developing controls using diffusion tensor imaging tractography. We aimed to explore…

  10. Identification of a de novo microdeletion 1q44 in a patient with hypogenesis of the corpus callosum, seizures and microcephaly - A case report.

    PubMed

    Westphal, Dominik S; Andres, Stephanie; Beitzel, Kirsten I; Makowski, Christine; Meitinger, Thomas; Hoefele, Julia

    2017-03-21

    Microdeletion 1q44 on the long arm of chromosome 1 leads to a phenotype that includes microcephaly, seizure, agenesis or hypogenesis of the corpus callosum, polydactyly, congenital heart defects and severe developmental delay along with characteristic facial dysmorphic signs. Until today, the distinct genetic causes for the different symptoms remain unclear. We here report a 1.2Mb de novo microdeletion 1q44 identified by performing a SNP array analysis. The female patient presented with microcephaly, seizure, hypogenesis of corpus callosum, postaxial hexadactyly, an atrial septal defect, a ventricular septal defect, hypertelorism, a long and smooth philtrum, thin vermilion borders, and micrognathia, all common features of microdeletion 1q44. An additionally performed chromosome analysis excluded any chromosomal rearrangements. The deleted region included the genes ZBTB18 as well as HNRNPU amongst others. Both are possibly candidate genes for the dysgenesis of the corpus callosum. AKT3, another candidate gene, was not affected by the deletion in this patient. Thus, the genetic findings in this case report spotlight ZBTB18 and HNRNPU in the genesis of the typical microdeletion 1q44 symptoms, especially concerning the dysgenesis of the corpus callosum, and therefore could help to unveil more of the genetic background of this syndrome.

  11. Traumatic axonal injury: the prognostic value of lesion load in corpus callosum, brain stem, and thalamus in different magnetic resonance imaging sequences.

    PubMed

    Moen, Kent G; Brezova, Veronika; Skandsen, Toril; Håberg, Asta K; Folvik, Mari; Vik, Anne

    2014-09-01

    The aim of this study was to explore the prognostic value of visible traumatic axonal injury (TAI) loads in different MRI sequences from the early phase after adjusting for established prognostic factors. Likewise, we sought to explore the prognostic role of early apparent diffusion coefficient (ADC) values in normal-appearing corpus callosum. In this prospective study, 128 patients (mean age, 33.9 years; range, 11-69) with moderate (n = 64) and severe traumatic brain injury (TBI) were examined with MRI at a median of 8 days (range, 0-28) postinjury. TAI lesions in fluid-attenuated inversion recovery (FLAIR), diffusion-weighted imaging (DWI), and T2*-weighted gradient echo (T2*GRE) sequences were counted and FLAIR lesion volumes estimated. In patients and 47 healthy controls, mean ADC values were computed in 10 regions of interests in the normal-appearing corpus callosum. Outcome measure was the Glasgow Outcome Scale-Extended (GOS-E) at 12 months. In patients with severe TBI, number of DWI lesions and volume of FLAIR lesions in the corpus callosum, brain stem, and thalamus predicted outcome in analyses with adjustment for age, Glasgow Coma Scale score, and pupillary dilation (odds ratio, 1.3-6.9; p = <0.001-0.017). The addition of Rotterdam CT score and DWI lesions in the corpus callosum yielded the highest R2 (0.24), compared to all other MRI variables, including brain stem lesions. For patients with moderate TBI only the number of cortical contusions (p = 0.089) and Rotterdam CT score (p = 0.065) tended to predict outcome. Numbers of T2*GRE lesions did not affect outcome. Mean ADC values in the normal-appearing corpus callosum did not differ from controls. In conclusion, the loads of visible TAI lesions in the corpus callosum, brain stem, and thalamus in DWI and FLAIR were independent prognostic factors in patients with severe TBI. DWI lesions in the corpus callosum were the most important predictive MRI variable. Interestingly, number of cortical

  12. Brief Report: VAX1 mutation associated with microphthalmia, corpus callosum agenesis and orofacial clefting – the first description of a VAX1 phenotype in humans

    PubMed Central

    Slavotinek, Anne M.; Chao, Ryan; Vacik, Tomas; Yahyavi, Mani; Abouzeid, Hana; Bardakjian, Tanya; Schneider, Adele; Shaw, Gary; Sherr, Elliott H.; Lemke, Greg; Youssef, Mohammed; Schorderet, Daniel F.

    2011-01-01

    Vax1 and Vax2 have been implicated in eye development and the closure of the choroid fissure in mice and zebrafish. We sequenced the coding exons of VAX1 and VAX2 in 70 patients with anophthalmia/microphthalmia. In VAX1, we observed homozygosity for two successive nucleotide substitutions c.453G>A and c.454C>A, predicting p.Arg152Ser, in a proband of Egyptian origin with microphthalmia, small optic nerves, cleft lip/palate and corpus callosum agenesis. This mutation affects an invariant residue in the homeodomain of VAX1 and was absent from 96 Egyptian controls. It is likely that the mutation results in a loss of function, as the mutation results in a phenotype similar to the Vax1 homozygous null mouse. We did not identify any mutations in VAX2. This is the first description of a phenotype associated with a VAX1 mutation in humans and establishes VAX1 as a new causative gene for anophthalmia/microphthalmia. PMID:22095910

  13. Binocular Interactions in the Lateral Suprasylvian Visual Area of Strabismic Cats Following Section of the Corpus Callosum.

    PubMed

    Di Stefano, M.; Lepore, F.; Ptito, M.; Bédard, S.; Marzi, C. A.; Guillemot, J. P.

    1991-01-01

    Visually responsive neurons have been recorded in the lateral suprasylvian area (LSA) of cats raised with either a convergent or a divergent strabismus. In contrast to areas 17 and 18, where many studies have documented a profound loss of binocularly activated neurons following early strabismus, in the LSA the majority of cells could still be binocularly driven. Acute or chronic section of the splenium of the corpus callosum reduced but did not abolish binocularity in the LSA. We propose that the widespread callosal connections, the large size of the receptive fields and the peculiar internal circuitry of the LSA all concur in permitting the maintenance of binocular coding in spite of early misalignment of the eyes.

  14. Hyperlexia and ambient echolalia in a case of cerebral infarction of the left anterior cingulate cortex and corpus callosum.

    PubMed

    Suzuki, Tadashi; Itoh, Shouichi; Hayashi, Mototaka; Kouno, Masako; Takeda, Katsuhiko

    2009-10-01

    We report the case of a 69-year-old woman with cerebral infarction in the left anterior cingulate cortex and corpus callosum. She showed hyperlexia, which was a distinctive reading phenomenon, as well as ambient echolalia. Clinical features also included complex disorders such as visual groping, compulsive manipulation of tools, and callosal disconnection syndrome. She read words written on the cover of a book and repeated words emanating from unrelated conversations around her or from hospital announcements. The combination of these two features due to a focal lesion has never been reported previously. The supplementary motor area may control the execution of established subroutines according to external and internal inputs. Hyperlexia as well as the compulsive manipulation of tools could be interpreted as faulty inhibition of preexisting essentially intact motor subroutines by damage to the anterior cingulate cortex reciprocally interconnected with the supplementary motor area.

  15. Agenesis of the corpus callosum in Turner's syndrome: report of a case and review of the literature.

    PubMed

    Lee, Ying-Ying; Hung, June; Chang, Ting-Yu; Huang, Chin-Chang

    2008-09-01

    Turner's syndrome (TS) is a genetic disorder caused by loss of entire or a substantial part of the X-chromosome, but association with central nervous system (CNS) abnormalities is rarely reported. A 32-year-old female with TS was found to have agenesis of the corpus callosum (ACC) and various clinical features including coarctation of aorta, hypertelorism, small jaw, short and webbed neck, cubitus valgus, and absence of the uterus. Karyotype analysis revealed X monosomy cell line (45, X). There have been only three other cases of TS associated with ACC. High prenatal lethality of TS fetuses with congenital CNS malformations may decrease the incidence of this association. Neuropsychological studies showed a normal intelligence neither prominent learning disability nor discrepancy between verbal and non-verbal items.

  16. Blindness, dancing extremities, and corpus callosum and brain stem involvement: an unusual presentation of fulminant subacute sclerosing panencephalitis.

    PubMed

    Singhi, Pratibha; Saini, Arushi Gahlot; Sankhyan, Naveen; Gupta, Pankaj; Vyas, Sameer

    2015-01-01

    A 4-year-old girl presented with acute visual loss followed 2 weeks later with loss of speech and audition, fulminant neuroregression, and choreo-athetoid movements of extremities. Fundus showed bilateral chorioretinitis. Electroencephalography showed periodic complexes. Measles antibody titers were elevated in both serum and cerebrospinal fluid, consistent with subacute sclerosing panencephalitis. Neuroimaging showed discontiguous involvement of splenium of the corpus callosum and ventral pons with sparing of cortical white matter. Our case highlights the atypical clinical and radiologic presentations of subacute sclerosing panencephalitis. Pediatricians need to be aware that necrotizing chorioretinitis in a child and/or atypical brain stem changes could be the heralding feature of this condition in endemic countries.

  17. Taurine attenuates hippocampal and corpus callosum damage, and enhances neurological recovery after closed head injury in rats.

    PubMed

    Gu, Y; Zhao, Y; Qian, K; Sun, M

    2015-04-16

    The protective effects of taurine against closed head injury (CHI) have been reported. This study was designed to investigate whether taurine reduced white matter damage and hippocampal neuronal death through suppressing calpain activation after CHI in rats. Taurine (50 mg/kg) was administered intravenously 30 min and 4 h again after CHI. It was found that taurine lessened the corpus callosum damage, attenuated the neuronal cell death in hippocampal CA1 and CA3 subfields and improved the neurological functions 7 days after CHI. Moreover, it suppressed the over-activation of calpain, enhanced the levels of calpastatin, and reduced the degradation of neurofilament heavy protein, myelin basic protein and αII-spectrin in traumatic tissue 24 h after CHI. These data confirm the protective effects of taurine against gray and white matter damage due to CHI, and suggest that down-regulating calpain activation could be one of the protective mechanisms of taurine against CHI.

  18. Agenesis of the corpus callosum in ddN strain mouse associated with unusual facial appearance (flat-face).

    PubMed

    Ozaki, H S; Murakami, T H; Toyoshima, T; Shimada, M

    1984-02-01

    In the course of an experiment involving brother-sister matings between ddN strain mice, mice occurred with an unusual facial appearance (flat-face). Subsequently, 4 mice with flat-face were bred from the litters of the second birth (ca. 10% frequency). This flat-face was assumed to be the result of a malformed short nose, hypoplastic maxilla and mandible, and hypertelorism. These 4 flat-face mice exhibited no significant delays in growth, motor ability or the development of learning ability. Histologically, they were all characterized by an almost total absence of callosal fibers and the presence of abnormal longitudinal neuromatous bundles. Therefore, the flat-face mice may be useful as experimental animals for brain research, as one can easily judge that they lack the corpus callosum from the facial appearance.

  19. [Tachistoscope and dichotic listening test of the subject after the transection of the posterior part of the corpus callosum].

    PubMed

    Watanabe, S; Tasaki, H; Hojo, K; Yoshimura, I; Sato, T; Nakaoka, T; Iwabuchi, T

    1982-06-01

    The authors made neuropsychological studies by the tachistoscope and the dichotic listening test on a subject who had undergone the transection of the posterior part of the corpus callosum. As to the tachistoscopic recognition, stimulus material was composed with the various Japanese letters (Katakana, Hiragana, Kanji), various faces (variations of the eyebrow form and the mouth form) and various slopes of line. Table 1 shows results of the cases (the subject was the present case, subjects 1 and subject 2 were past cases). It was seen that the performance of the subject on Japanese letters tasks showed greater right visual field superiority than the one of subject 1 and subject 2. As to the auditory recognition, the tasks used for the dichotic listening test were the following (Table 2, 3, 4). Different digits (three pairs) of the subject showed greater right ear superiority (right ear: 61.1, left ear 5.9) than the ones of subject 1 and subject 2.

  20. Auditory interhemispheric transfer in relation to patterns of partial agenesis and hypoplasia of the corpus callosum in spina bifida meningomyelocele

    PubMed Central

    Hannay, H. Julia; Walker, Amy; Dennis, Maureen; Kramer, Larry; Blaser, Susan; Fletcher, Jack M.

    2009-01-01

    Spina bifida meningomyelocele with hydrocephalus (SBM) is commonly associated with anomalies of the corpus callosum (CC). We describe MRI patterns of regional CC agenesis and relate CC anomalies to functional laterality based on a dichotic listening test in 90 children with SBM and 27 typically developing controls. Many children with SBM (n = 40) showed regional CC anomalies in the form of agenesis of the rostrum and0or splenium, and a smaller number (n = 20) showed hypoplasia (thinning) of all CC regions (rostrum, genu, body, and splenium). The expected right ear advantage (REA) was exhibited by normal controls and children with SBM having a normal or hypoplastic splenium. It was not shown by children with SBM who were left handed, missing a splenium, or had a higher level spinal cord lesion. Perhaps the right hemisphere of these children is more involved in processing some aspects of linguistic stimuli. PMID:18764972

  1. Conduct disorder in females is associated with reduced corpus callosum structural integrity independent of comorbid disorders and exposure to maltreatment

    PubMed Central

    Lindner, P; Savic, I; Sitnikov, R; Budhiraja, M; Liu, Y; Jokinen, J; Tiihonen, J; Hodgins, S

    2016-01-01

    The behavioral phenotype and genotype of conduct disorder (CD) differ in males and females. Abnormalities of white matter integrity have been reported among males with CD and antisocial personality disorder (ASPD). Little is known about white matter integrity in females with CD. The present study aimed to determine whether abnormalities of white matter are present among young women who presented CD before the age of 15, and whether abnormalities are independent of the multiple comorbid disorders and experiences of maltreatment characterizing females with CD that may each in themselves be associated with alterations of the white matter. Three groups of women, aged on average 24 years, were scanned using diffusion tensor imaging and compared: 28 with prior CD, three of whom presented ASPD; a clinical comparison (CC) group of 15 women with no history of CD but with similar proportions who presented alcohol dependence, drug dependence, anxiety disorders, depression disorders and physical and sexual abuse as the CD group; and 24 healthy women. Whole-brain, tract-based spatial statistics were computed to investigate differences in fractional anisotropy, axial diffusivity and radial diffusivity. Compared with healthy women, women with prior CD showed widespread reductions in axial diffusivity primarily in frontotemporal regions. After statistically adjusting for comorbid disorders and maltreatment, group differences in the corpus callosum body and genu (including forceps minor) remained significant. Compared with the CC group, women with CD showed reduced fractional anisotropy in the body and genu of the corpus callosum. No differences were detected between the CD and healthy women in the uncinate fasciculus. PMID:26784968

  2. Myelination of the corpus callosum in male and female rats following complex environment housing during adulthood

    PubMed Central

    Markham, Julie A.; Herting, Megan M.; Luszpak, Agatha E.; Juraska, Janice M.; Greenough, William T.

    2009-01-01

    Myelination is an important process in brain development, and delays or abnormalities in this process have been associated with a number of conditions including autism, developmental delay, attention deficit disorder, and schizophrenia. Myelination can be sensitive to developmental experience; however, although the adult brain remains highly plastic, it is unknown whether myelination continues to be sensitive to experience during adulthood. Male and female rats were socially housed until four months of age, at which time they were moved into either a complex or “enriched” environment (EC) or an isolated condition (IC). Although the area of the splenium (posterior 20% of the callosum, which contains axons from visual cortical neurons) increased by about 10% following two months of EC housing, the area occupied by myelinated axons was not influenced by adult housing condition. Instead, it was the area occupied by glial cell processes and unmyelinated axons which significantly increased following EC housing. Neither the size nor the myelin content of the genu (anterior 15% of the callosum) was sensitive to manipulations of adult housing condition, but males had more area occupied by myelinated axons in both callosal regions. Finally, the inability of two months of complex environment housing during adulthood to impact the number of myelinated axons in the splenium was confirmed in a subset of animals using quantitative electron microscopy. We conclude that the sensitivity of myelination to experience is reduced in adulthood relative to development in both sexes. PMID:19596280

  3. Fetal development of the corpus callosum: Insights from a 3T DTI and tractography study in a patient with segmental callosal agenesis.

    PubMed

    Scola, Elisa; Sirgiovanni, Ida; Avignone, Sabrina; Cinnante, Claudia Maria; Biffi, Riccardo; Fumagalli, Monica; Triulzi, Fabio

    2016-10-01

    Commissural embryology mechanisms are not yet completely understood. The study and comprehension of callosal dysgenesis can provide remarkable insights into embryonic or fetal commissural development. The diffusion tensor imaging (DTI) technique allows the in vivo analyses of the white-matter microstructure and is a valid tool to clarify the disturbances of brain connections in patients with dysgenesis of the corpus callosum (CC). The segmental callosal agenesis (SCAG) is a rare partial agenesis of the corpus callosum (ACC). In a newborn with SCAG the DTI and tractography analyses proved that the CC was made of two separate segments consisting respectively of the ventral part in the genu and body of the CC, connecting the frontal lobes, and the dorsal part in the CC splenium and the attached hippocampal commissure (HC), connecting the parietal lobes and the fornix. These findings support the embryological thesis of a separated origin of the ventral and the dorsal parts of the CC.

  4. EphB1 and EphB2 intracellular domains regulate the formation of the corpus callosum and anterior commissure.

    PubMed

    Robichaux, Michael A; Chenaux, George; Ho, Hsin-Yi Henry; Soskis, Michael J; Greenberg, Michael E; Henkemeyer, Mark; Cowan, Christopher W

    2016-04-01

    The two cortical hemispheres of the mammalian forebrain are interconnected by major white matter tracts, including the corpus callosum (CC) and the posterior branch of the anterior commissure (ACp), that bridge the telencephalic midline. We show here that the intracellular signaling domains of the EphB1 and EphB2 receptors are critical for formation of both the ACp and CC. We observe partial and complete agenesis of the corpus callosum, as well as highly penetrant ACp misprojection phenotypes in truncated EphB1/2 mice that lack intracellular signaling domains. Consistent with the roles for these receptors in formation of the CC and ACp, we detect expression of these receptors in multiple brain regions associated with the formation of these forebrain structures. Taken together, our findings suggest that a combination of forward and reverse EphB1/2 receptor-mediated signaling contribute to ACp and CC axon guidance.

  5. Sex differences in the relationship between planum temporale asymmetry and corpus callosum morphology in chimpanzees (Pan troglodytes): A combined MRI and DTI analysis.

    PubMed

    Hopkins, William D; Hopkins, Anna M; Misiura, Maria; Latash, Elitaveta M; Mareno, Mary Catherine; Schapiro, Steven J; Phillips, Kimberley A

    2016-12-01

    Increases brain size has been hypothesized to be inversely associated with the expression of behavioral and brain asymmetries within and between species. We tested this hypothesis by analyzing the relation between asymmetries in the planum temporale (PT) and different measures of the corpus callosum (CC) including surface area, streamline count as measured from diffusion tensor imaging, fractional anisotropy values and the ratio in the number of fibers to surface area in a sample of chimpanzees. We found that chimpanzees with larger PT asymmetries in absolute terms had smaller CC surface areas, fewer streamlines and a smaller ratio of fibers to surface area. These results were largely specific to male but not female chimpanzees. Our results partially support the hypothesis that brain asymmetries are linked to variation in corpus callosum morphology, although these associations may be sex-dependent.

  6. Why size matters: differences in brain volume account for apparent sex differences in callosal anatomy: the sexual dimorphism of the corpus callosum.

    PubMed

    Luders, Eileen; Toga, Arthur W; Thompson, Paul M

    2014-01-01

    Numerous studies have demonstrated a sexual dimorphism of the human corpus callosum. However, the question remains if sex differences in brain size, which typically is larger in men than in women, or biological sex per se account for the apparent sex differences in callosal morphology. Comparing callosal dimensions between men and women matched for overall brain size may clarify the true contribution of biological sex, as any observed group difference should indicate pure sex effects. We thus examined callosal morphology in 24 male and 24 female brains carefully matched for overall size. In addition, we selected 24 extremely large male brains and 24 extremely small female brains to explore if observed sex effects might vary depending on the degree to which male and female groups differed in brain size. Using the individual T1-weighted brain images (n=96), we delineated the corpus callosum at midline and applied a well-validated surface-based mesh-modeling approach to compare callosal thickness at 100 equidistant points between groups determined by brain size and sex. The corpus callosum was always thicker in men than in women. However, this callosal sex difference was strongly determined by the cerebral sex difference overall. That is, the larger the discrepancy in brain size between men and women, the more pronounced the sex difference in callosal thickness, with hardly any callosal differences remaining between brain-size matched men and women. Altogether, these findings suggest that individual differences in brain size account for apparent sex differences in the anatomy of the corpus callosum.

  7. Contribution of the corpus callosum to bilateral representation of the trunk midline in the human brain: an fMRI study of callosotomized patients.

    PubMed

    Fabri, M; Polonara, G; Mascioli, G; Paggi, A; Salvolini, U; Manzoni, T

    2006-06-01

    Human brain studies have shown that the cutaneous receptors of trunk regions close to the midline are represented in the first somatosensory cortex (SI) of both hemispheres. The present study aims to establish whether in humans, as in non-human primates, the bilateral representation of the trunk midline in area SI depends on the corpus callosum. Data were obtained from eight callosotomized patients: three with complete callosal resection, one with a partial posterior resection including the splenium and the callosal trunk, and four with partial anterior resections sparing the splenium and in one case also the posterior part of the callosal trunk. The investigation was carried out with functional magnetic resonance imaging. Unilateral tactile stimulation was applied by rubbing ventral trunk regions close to the midline (about 20 x 10 cm in width) with a soft cotton pad (frequency 1 Hz). Cortical activation foci elicited by unilateral stimulation of cutaneous regions adjacent to the midline were detected in the contralateral post-central gyrus (PCG), in a region corresponding to the trunk ventral midline representation zone of area SI, as described in a previous study of intact subjects. In most patients, activation foci were also found in the ipsilateral PCG, again as in subjects with an intact corpus callosum. The data confirm that the skin regions adjacent to the trunk midline are represented bilaterally in SI, and indicate that ipsilateral activation is at least partially independent of the corpus callosum.

  8. [A case of left hemi-facial metamorphopsia induced by infarction of the right side of the splenium of the corpus callosum].

    PubMed

    Saito, Yuki; Matsunaga, Akiko; Yamamura, Osamu; Ikawa, Masamichi; Hamano, Tadanori; Yoneda, Makoto

    2014-01-01

    We describe a patient, 61-year-old left-handed Japanese woman, who presented with left hemi-facial metamorphopsia after infarct that extended from the splenium of the corpus callosum to the major forceps on the right side. Past medical history revealed a right putaminal hemorrhage with amnesic aphasia. She complained that the right side of people's faces, that is, the left side when visualized by her, seemed distorted. When she looked at other people's faces, the right half of the faces looked smaller than the left half, and the eyes, noses, and mouths appeared to be hanging toward the center of their faces. This phenomenon was observed for whomever she visualized. She stated that objects other than the face looked normal. Her visual acuity and visual field were normal. Callosal disconnection syndrome was not presented. Magnetic resonance imaging of the brain on diffusion weighted image revealed a high intensity area that extended from the splenium of the corpus callosum to the major forceps on the right side. Electroencephalography did not show any epileptic discharge. Her visual symptoms improved gradually. The mechanism of hemi-facial metamorphopsia remains obscure. We hypothesized that this patient developed left hemi-facial metamorphopsia because of the disrupted transfer of visual information of the left side of face at the splenium of the corpus callosum and the major forceps, which may be the responsible lesion of hemi-facial metamorphopsia.

  9. Surface-based vertexwise analysis of morphometry and microstructural integrity for white matter tracts in diffusion tensor imaging: With application to the corpus callosum in Alzheimer's disease.

    PubMed

    Tang, Xiaoying; Qin, Yuanyuan; Zhu, Wenzhen; Miller, Michael I

    2017-04-01

    In this article, we present a unified statistical pipeline for analyzing the white matter (WM) tracts morphometry and microstructural integrity, both globally and locally within the same WM tract, from diffusion tensor imaging. Morphometry is quantified globally by the volumetric measurement and locally by the vertexwise surface areas. Meanwhile, microstructural integrity is quantified globally by the mean fractional anisotropy (FA) and trace values within the specific WM tract and locally by the FA and trace values defined at each vertex of its bounding surface. The proposed pipeline consists of four steps: (1) fully automated segmentation of WM tracts in a multi-contrast multi-atlas framework; (2) generation of the smooth surface representations for the WM tracts of interest; (3) common template surface generation on which the localized morphometric and microstructural statistics are defined and a variety of statistical analyses can be conducted; (4) multiple comparison correction to determine the significance of the statistical analysis results. Detailed herein, this pipeline has been applied to the corpus callosum in Alzheimer's disease (AD) with significantly decreased FA values and increased trace values, both globally and locally, being detected in patients with AD when compared to normal aging populations. A subdivision of the corpus callosum in both hemispheres revealed that the AD pathology primarily affects the body and splenium of the corpus callosum. Validation analyses and two multiple comparison correction strategies are provided. Hum Brain Mapp 38:1875-1893, 2017. © 2017 Wiley Periodicals, Inc.

  10. Regional Microstructural and Volumetric Magnetic Resonance Imaging (MRI) Abnormalities in the Corpus Callosum of Neonates With Congenital Heart Defect Undergoing Cardiac Surgery.

    PubMed

    Hagmann, Cornelia; Singer, Jitka; Latal, Beatrice; Knirsch, Walter; Makki, Malek

    2016-03-01

    The purpose of the study is to investigate the structural development of the corpus callosum in term neonates with congenital heart defect before and after surgery using diffusion tensor imaging and 3-dimensional T1-weighted magnetic resonance imaging (MRI). We compared parallel and radial diffusions, apparent diffusion coefficient (ADC), fractional anisotropy, and volume of 5 substructures of the corpus callosum: genu, rostral body, body, isthmus, and splenium. Compared to healthy controls, we found a significantly lower volume of the splenium and total corpus callosum and a higher radial diffusion and lower fractional anisotropy in the splenium of patients presurgery; a lower volume in all substructures in the postsurgery group; higher radial diffusion in the rostral body, body, and splenium; and a higher apparent diffusion coefficient in the splenium of postsurgery patients. Similar fractional anisotropy changes in congenital heart defect patients were reported in preterm infants. Our findings in apparent diffusion coefficient in the splenium of these patients (pre and postsurgery) are comparable to findings in preterm neonates with psychomotor delay. Delayed maturation of the isthmus was also reported in preterm infants.

  11. Age at First Exposure to Football Is Associated with Altered Corpus Callosum White Matter Microstructure in Former Professional Football Players

    PubMed Central

    Stamm, Julie M.; Koerte, Inga K.; Muehlmann, Marc; Pasternak, Ofer; Bourlas, Alexandra P.; Baugh, Christine M.; Giwerc, Michelle Y.; Zhu, Anni; Coleman, Michael J.; Bouix, Sylvain; Fritts, Nathan G.; Martin, Brett M.; Chaisson, Christine; McClean, Michael D.; Lin, Alexander P.; Cantu, Robert C.; Tripodis, Yorghos; Shenton, Martha E.

    2015-01-01

    Abstract Youth football players may incur hundreds of repetitive head impacts (RHI) in one season. Our recent research suggests that exposure to RHI during a critical neurodevelopmental period prior to age 12 may lead to greater later-life mood, behavioral, and cognitive impairments. Here, we examine the relationship between age of first exposure (AFE) to RHI through tackle football and later-life corpus callosum (CC) microstructure using magnetic resonance diffusion tensor imaging (DTI). Forty retired National Football League (NFL) players, ages 40–65, were matched by age and divided into two groups based on their AFE to tackle football: before age 12 or at age 12 or older. Participants underwent DTI on a 3 Tesla Siemens (TIM-Verio) magnet. The whole CC and five subregions were defined and seeded using deterministic tractography. Dependent measures were fractional anisotropy (FA), trace, axial diffusivity, and radial diffusivity. Results showed that former NFL players in the AFE <12 group had significantly lower FA in anterior three CC regions and higher radial diffusivity in the most anterior CC region than those in the AFE ≥12 group. This is the first study to find a relationship between AFE to RHI and later-life CC microstructure. These results suggest that incurring RHI during critical periods of CC development may disrupt neurodevelopmental processes, including myelination, resulting in altered CC microstructure. PMID:26200068

  12. Osseous oral hyaline ring granuloma mimicking a mandible tumor in a child with congenital agenesis of the corpus callosum

    PubMed Central

    Neves-Silva, Rodrigo; Ferreira-Gomes, Camilla-Borges; Palmier, Natalia; Brum-Corrêa, Marcelo; Paes-Almeida, Oslei; Ajudarte-Lopes, Marcio; Agustin-Vargas, Pablo

    2017-01-01

    Background Hyaline ring granuloma (HRG) of the oral cavity is an uncommon disorder considered to be a foreign-body reaction resulting from implantation of food vegetable particles. Microscopically, it is characterized by the presence of structures of hyaline rings in an inflamed fibrous tissue background, which contains multinucleated giant cells. Material and Methods We present the case of a 4-year-old boy diagnosed with a mandible osseous HRG, which showed clinical and tomographic aspects suggestive of an aggressive bone tumor. Results The patient underwent surgical exploration and histopathologic analysis showed fragments composed predominantly of widespread dense connective tissue with an acute and chronic inflammatory infiltrate containing multinucleated giant cells and scattered areas of eosinophilic material associated with hyaline rings, strongly suggestive of vegetable particles. The eosinophilic material was positive for periodic acid-Schiff (PAS) and resistant to diastase digestion. These features led to diagnosis of osseous HRG. Scanning electron microscopy (SEM) analysis was performed for illustrative purposes and the multiple structures resembling vegetable particles were characterized in more detail. Conclusions Although rare, this case highlights the importance of the clinician’s awareness regarding the existence of an osseous counterpart of HRG. Key words:Agenesis of the corpus callosum, child, hyaline ring granuloma, intraosseous, mandible, pulse granuloma. PMID:28210458

  13. Decreased survival in glioblastomas is specific to contact with the ventricular-subventricular zone, not subgranular zone or corpus callosum.

    PubMed

    Mistry, Akshitkumar M; Dewan, Michael C; White-Dzuro, Gabrielle A; Brinson, Philip R; Weaver, Kyle D; Thompson, Reid C; Ihrie, Rebecca A; Chambless, Lola B

    2017-04-01

    The clinical effect of radiographic contact of glioblastoma (GBM) with neurogenic zones (NZ)-the ventricular-subventricular (VSVZ) and subgranular (SGZ) zones-and the corpus callosum (CC) remains unclear and, in the case of the SGZ, unexplored. We investigated (1) if GBM contact with a NZ correlates with decreased survival; (2) if so, whether this effect is associated with a specific NZ; and (3) if radiographic contact with or invasion of the CC by GBM is associated with decreased survival. We retrospectively identified 207 adult patients who underwent cytoreductive surgery for GBM followed by chemotherapy and/or radiation. Age, preoperative Karnofsky performance status score (KPS), and extent of resection were recorded. Preoperative MRIs were blindly analyzed to calculate tumor volume and assess its contact with VSVZ, SGZ, CC, and cortex. Overall (OS) and progression free (PFS) survivals were calculated and analyzed with multivariate Cox analyses. Among the 207 patients, 111 had GBM contacting VSVZ (VSVZ+GBMs), 23 had SGZ+GBMs, 52 had CC+GBMs, and 164 had cortex+GBMs. VSVZ+, SGZ+, and CC+ GBMs were significantly larger in size relative to their respective non-contacting controls. Multivariate Cox survival analyses revealed GBM contact with the VSVZ, but not SGZ, CC, or cortex, as an independent predictor of lower OS, PFS, and early recurrence. We hypothesize that the VSVZ niche has unique properties that contribute to GBM pathobiology in adults.

  14. SLC1A4 mutations cause a novel disorder of intellectual disability, progressive microcephaly, spasticity and thin corpus callosum.

    PubMed

    Heimer, G; Marek-Yagel, D; Eyal, E; Barel, O; Oz Levi, D; Hoffmann, C; Ruzzo, E K; Ganelin-Cohen, E; Lancet, D; Pras, E; Rechavi, G; Nissenkorn, A; Anikster, Y; Goldstein, D B; Ben Zeev, B

    2015-10-01

    Two unrelated patients, presenting with significant global developmental delay, severe progressive microcephaly, seizures, spasticity and thin corpus callosum (CC) underwent trio whole-exome sequencing. No candidate variant was found in any known genes related to the phenotype. However, crossing the data of the patients illustrated that they both manifested pathogenic variants in the SLC1A4 gene which codes the ASCT1 transporter of serine and other neutral amino acids. The Ashkenazi patient is homozygous for a deleterious missense c.766G>A, p.(E256K) mutation whereas the Ashkenazi-Iraqi patient is compound heterozygous for this mutation and a nonsense c.945delTT, p.(Leu315Hisfs*42) mutation. Structural prediction demonstrates truncation of significant portion of the protein by the nonsense mutation and speculates functional disruption by the missense mutation. Both mutations are extremely rare in general population databases, however, the missense mutation was found in heterozygous mode in 1:100 Jewish Ashkenazi controls suggesting a higher carrier rate among Ashkenazi Jews. We conclude that SLC1A4 is the disease causing gene of a novel neurologic disorder manifesting with significant intellectual disability, severe postnatal microcephaly, spasticity and thin CC. The role of SLC1A4 in the serine transport from astrocytes to neurons suggests a possible pathomechanism for this disease and implies a potential therapeutic approach.

  15. Agenesis of the corpus callosum and gray matter heterotopia in three patients with constitutional mismatch repair deficiency syndrome.

    PubMed

    Baas, Annette F; Gabbett, Michael; Rimac, Milan; Kansikas, Minttu; Raphael, Martine; Nievelstein, Rutger Aj; Nicholls, Wayne; Offerhaus, Johan; Bodmer, Danielle; Wernstedt, Annekatrin; Krabichler, Birgit; Strasser, Ulrich; Nyström, Minna; Zschocke, Johannes; Robertson, Stephen P; van Haelst, Mieke M; Wimmer, Katharina

    2013-01-01

    Constitutional mismatch repair deficiency (CMMR-D) syndrome is a rare inherited childhood cancer predisposition caused by biallelic germline mutations in one of the four mismatch repair (MMR)-genes, MLH1, MSH2, MSH6 or PMS2. Owing to a wide tumor spectrum, the lack of specific clinical features and the overlap with other cancer predisposing syndromes, diagnosis of CMMR-D is often delayed in pediatric cancer patients. Here, we report of three new CMMR-D patients all of whom developed more than one malignancy. The common finding in these three patients is agenesis of the corpus callosum (ACC). Gray matter heterotopia is present in two patients. One of the 57 previously reported CMMR-D patients with brain tumors (therefore all likely had cerebral imaging) also had ACC. With the present report the prevalence of cerebral malformations is at least 4/60 (6.6%). This number is well above the population birth prevalence of 0.09-0.36 live births with these cerebral malformations, suggesting that ACC and heterotopia are features of CMMR-D. Therefore, the presence of cerebral malformations in pediatric cancer patients should alert to the possible diagnosis of CMMR-D. ACC and gray matter heterotopia are the first congenital malformations described to occur at higher frequency in CMMR-D patients than in the general population. Further systematic evaluations of CMMR-D patients are needed to identify possible other malformations associated with this syndrome.

  16. Age at First Exposure to Football Is Associated with Altered Corpus Callosum White Matter Microstructure in Former Professional Football Players.

    PubMed

    Stamm, Julie M; Koerte, Inga K; Muehlmann, Marc; Pasternak, Ofer; Bourlas, Alexandra P; Baugh, Christine M; Giwerc, Michelle Y; Zhu, Anni; Coleman, Michael J; Bouix, Sylvain; Fritts, Nathan G; Martin, Brett M; Chaisson, Christine; McClean, Michael D; Lin, Alexander P; Cantu, Robert C; Tripodis, Yorghos; Stern, Robert A; Shenton, Martha E

    2015-11-15

    Youth football players may incur hundreds of repetitive head impacts (RHI) in one season. Our recent research suggests that exposure to RHI during a critical neurodevelopmental period prior to age 12 may lead to greater later-life mood, behavioral, and cognitive impairments. Here, we examine the relationship between age of first exposure (AFE) to RHI through tackle football and later-life corpus callosum (CC) microstructure using magnetic resonance diffusion tensor imaging (DTI). Forty retired National Football League (NFL) players, ages 40-65, were matched by age and divided into two groups based on their AFE to tackle football: before age 12 or at age 12 or older. Participants underwent DTI on a 3 Tesla Siemens (TIM-Verio) magnet. The whole CC and five subregions were defined and seeded using deterministic tractography. Dependent measures were fractional anisotropy (FA), trace, axial diffusivity, and radial diffusivity. Results showed that former NFL players in the AFE <12 group had significantly lower FA in anterior three CC regions and higher radial diffusivity in the most anterior CC region than those in the AFE ≥12 group. This is the first study to find a relationship between AFE to RHI and later-life CC microstructure. These results suggest that incurring RHI during critical periods of CC development may disrupt neurodevelopmental processes, including myelination, resulting in altered CC microstructure.

  17. Application of fractal and grey level co-occurrence matrix analysis in evaluation of brain corpus callosum and cingulum architecture.

    PubMed

    Pantic, Igor; Dacic, Sanja; Brkic, Predrag; Lavrnja, Irena; Pantic, Senka; Jovanovic, Tomislav; Pekovic, Sanja

    2014-10-01

    This aim of this study was to assess the discriminatory value of fractal and grey level co-occurrence matrix (GLCM) analysis methods in standard microscopy analysis of two histologically similar brain white mass regions that have different nerve fiber orientation. A total of 160 digital micrographs of thionine-stained rat brain white mass were acquired using a Pro-MicroScan DEM-200 instrument. Eighty micrographs from the anterior corpus callosum and eighty from the anterior cingulum areas of the brain were analyzed. The micrographs were evaluated using the National Institutes of Health ImageJ software and its plugins. For each micrograph, seven parameters were calculated: angular second moment, inverse difference moment, GLCM contrast, GLCM correlation, GLCM variance, fractal dimension, and lacunarity. Using the Receiver operating characteristic analysis, the highest discriminatory value was determined for inverse difference moment (IDM) (area under the receiver operating characteristic (ROC) curve equaled 0.925, and for the criterion IDM≤0.610 the sensitivity and specificity were 82.5 and 87.5%, respectively). Most of the other parameters also showed good sensitivity and specificity. The results indicate that GLCM and fractal analysis methods, when applied together in brain histology analysis, are highly capable of discriminating white mass structures that have different axonal orientation.

  18. Inter-hemispheric functional dysconnectivity mediates the association of corpus callosum degeneration with memory impairment in AD and amnestic MCI

    PubMed Central

    Qiu, Yingwei; Liu, Siwei; Hilal, Saima; Loke, Yng Miin; Ikram, Mohammad Kamran; Xu, Xin; Yeow Tan, Boon; Venketasubramanian, Narayanaswamy; Chen, Christopher Li-Hsian; Zhou, Juan

    2016-01-01

    Evidences suggested that both corpus callosum (CC) degeneration and alternations of homotopic inter-hemispheric functional connectivity (FC) are present in Alzheimer’s disease (AD). However, the associations between region-specific CC degeneration and homotopic inter-hemispheric FC and their relationships with memory deficits in AD remain uncharacterized. We hypothesized that selective CC degeneration is associated with memory impairment in AD and amnestic mild cognitive impairment (aMCI), which is mediated by homotopic inter-hemispheric functional dysconnectivity. Using structural magnetic resonance imaging (MRI) and task-free functional MRI, we assessed the CC volume and inter-hemispheric FC in 66 healthy controls, 41 aMCI and 41 AD. As expected, AD had CC degeneration and attenuated inter-hemispheric homotopic FC. Nevertheless, aMCI had relatively less severe CC degeneration (mainly in mid-anterior, central, and mid-posterior) and no reduction in inter-hemispheric homotopic FC. The degeneration of each CC sub-region was associated with specific inter-hemispheric homotopic functional disconnections in AD and aMCI. More importantly, impairment of inter-hemispheric homotopic FC partially mediated the association between CC (particularly the central and posterior parts) degeneration and memory deficit. Notably, these results remained after controlling for hippocampal volume. Our findings shed light on how CC degeneration and the related inter-hemispheric FC impact memory impairment in early stage of AD. PMID:27581062

  19. Progesterone metabolism in the pineal, brain stem, thalamus and corpus callosum of the female rat.

    PubMed

    Hanukoglu, I; Karavolas, H J; Goy, R W

    1977-04-15

    Specific brain regions, namely, thalamus, tectum, tegmentum, cerebellum, medulla and pineal, from five proestrous rats were incubated for 30 min with [3H]progesterone. After reverse isotopic dilution analysis, the following metabolites were identified in all incubations by purification to constant specific activity, derivative formation and/or gas liquid chromatography trapping: [3H]5alpha-pregnane-3, 20-dione (10-20% of the starting substrate except pineal -- 0.7%), [3H]3alpha-hydroxy-5alpha-pregnan-20-one (1.6-3.8% except for pineal -- 0.5%) and [3H]20alpha-hydroxy-4-pregnen-3-one (0.05-0.11%). Preliminary results from the corpus collosum incubation indicated the presence of the same metabolites. Although some apparent constant specific activities were obtained for 20alpha-hydroxy-5alpha-pregnan-3-one and 5beta-pregnane-3, 20-dione, the low levels of 3H associated with these steroids did not permit a definitive identification. The results indicate the presence of at least delta1-steroid 5alpha-reductase, 3alpha-hydroxysteroid dehydrogenase and 20alpha-hydroxysteroid dehydrogenase activities with progesterone as substrate in the brain regions examined.

  20. Working memory and corpus callosum microstructural integrity after pediatric traumatic brain injury: a diffusion tensor tractography study.

    PubMed

    Treble, Amery; Hasan, Khader M; Iftikhar, Amal; Stuebing, Karla K; Kramer, Larry A; Cox, Charles S; Swank, Paul R; Ewing-Cobbs, Linda

    2013-10-01

    Deficits in working memory (WM) are a common consequence of pediatric traumatic brain injury (TBI) and are believed to contribute to difficulties in a range of cognitive and academic domains. Reduced integrity of the corpus callosum (CC) after TBI may disrupt the connectivity between bilateral frontoparietal neural networks underlying WM. In the present investigation, diffusion tensor imaging (DTI) tractography of eight callosal subregions (CC1-CC8) was examined in relation to measures of verbal and visuospatial WM in 74 children sustaining TBI and 49 typically developing comparison children. Relative to the comparison group, children with TBI demonstrated poorer visuospatial WM, but comparable verbal WM. Microstructure of the CC was significantly compromised in brain-injured children, with lower fractional anisotropy (FA) and higher axial and radial diffusivity metrics in all callosal subregions. In both groups of children, lower FA and/or higher radial diffusivity in callosal subregions connecting anterior and posterior parietal cortical regions predicted poorer verbal WM, whereas higher radial diffusivity in callosal subregions connecting anterior and posterior parietal, as well as temporal, cortical regions predicted poorer visuospatial WM. DTI metrics, especially radial diffusivity, in predictive callosal subregions accounted for significant variance in WM over and above remaining callosal subregions. Reduced microstructural integrity of the CC, particularly in subregions connecting parietal and temporal cortices, may act as a neuropathological mechanism contributing to long-term WM deficits. The future clinical use of neuroanatomical biomarkers may allow for the early identification of children at highest risk for WM deficits and earlier provision of interventions for these children.

  1. The Ciliogenic Transcription Factor RFX3 Regulates Early Midline Distribution of Guidepost Neurons Required for Corpus Callosum Development

    PubMed Central

    Benadiba, Carine; Magnani, Dario; Niquille, Mathieu; Morlé, Laurette; Valloton, Delphine; Nawabi, Homaira; Ait-Lounis, Aouatef; Otsmane, Belkacem; Reith, Walter; Theil, Thomas; Hornung, Jean-Pierre

    2012-01-01

    The corpus callosum (CC) is the major commissure that bridges the cerebral hemispheres. Agenesis of the CC is associated with human ciliopathies, but the origin of this default is unclear. Regulatory Factor X3 (RFX3) is a transcription factor involved in the control of ciliogenesis, and Rfx3–deficient mice show several hallmarks of ciliopathies including left–right asymmetry defects and hydrocephalus. Here we show that Rfx3–deficient mice suffer from CC agenesis associated with a marked disorganisation of guidepost neurons required for axon pathfinding across the midline. Using transplantation assays, we demonstrate that abnormalities of the mutant midline region are primarily responsible for the CC malformation. Conditional genetic inactivation shows that RFX3 is not required in guidepost cells for proper CC formation, but is required before E12.5 for proper patterning of the cortical septal boundary and hence accurate distribution of guidepost neurons at later stages. We observe focused but consistent ectopic expression of Fibroblast growth factor 8 (Fgf8) at the rostro commissural plate associated with a reduced ratio of GLIoma-associated oncogene family zinc finger 3 (GLI3) repressor to activator forms. We demonstrate on brain explant cultures that ectopic FGF8 reproduces the guidepost neuronal defects observed in Rfx3 mutants. This study unravels a crucial role of RFX3 during early brain development by indirectly regulating GLI3 activity, which leads to FGF8 upregulation and ultimately to disturbed distribution of guidepost neurons required for CC morphogenesis. Hence, the RFX3 mutant mouse model brings novel understandings of the mechanisms that underlie CC agenesis in ciliopathies. PMID:22479201

  2. A novel tool for the morphometric analysis of corpus callosum: applications to the diagnosis of autism - biomed 2009.

    PubMed

    Vatta, Federica; Mininel, Stefano; Colafati, Stefania G; D'Errico, Luigia; Malena, Saverio; Di Salle, Francesco

    2009-01-01

    Autism is a developmental disorder characterized by social deficits, impaired communication, and restricted and repetitive patterns of behaviour. Emerging theories indicate interregional functional and anatomical brain connectivity as a likely key feature in autism pathophysiology. Corpus callosum (CC) represents a natural target of autism connectivity research, being the expression of interhemispheric communication. In this paper, a novel method for a robust morphometric analysis of CC data is presented. The standard morphometric approach is based on the analysis of the size and shape of the CC midsagittal cross-section. As there are no gross anatomical landmarks that clearly delimit anatomically or functionally distinct CC regions, several geometric partitioning schemes have been proposed in the literature for morphometric analysis, subdividing CC into subregions whose fiber topography is expected to target different hemispheric cortical regions. A novel tool of morphometric analysis, based on the automated subdivision of a high number of partitions from a CC centroid and on the consequent determination of the CC anatomical landmarks is presented, allowing an automated analysis of CC volumes, shapes and curvatures, suitable for an automated application in clinical environment. Moreover the proposed tool can be used for original post-processing and visualization techniques that may help in the analysis of possible alterations of CC and in the correlations with autism-related diseases. The proposed morphometric tool has been validated and applied for clinical investigation on brain morphometry in children (age 3-11 years) with autism or with other autism spectrum disorders (DSA) and on healthy control subjects who underwent volumetric MRI T1 weighted acquisitions.

  3. Working Memory and Corpus Callosum Microstructural Integrity after Pediatric Traumatic Brain Injury: A Diffusion Tensor Tractography Study

    PubMed Central

    Treble, Amery; Hasan, Khader M.; Iftikhar, Amal; Stuebing, Karla K.; Kramer, Larry A.; Cox, Charles S.; Swank, Paul R.

    2013-01-01

    Abstract Deficits in working memory (WM) are a common consequence of pediatric traumatic brain injury (TBI) and are believed to contribute to difficulties in a range of cognitive and academic domains. Reduced integrity of the corpus callosum (CC) after TBI may disrupt the connectivity between bilateral frontoparietal neural networks underlying WM. In the present investigation, diffusion tensor imaging (DTI) tractography of eight callosal subregions (CC1–CC8) was examined in relation to measures of verbal and visuospatial WM in 74 children sustaining TBI and 49 typically developing comparison children. Relative to the comparison group, children with TBI demonstrated poorer visuospatial WM, but comparable verbal WM. Microstructure of the CC was significantly compromised in brain-injured children, with lower fractional anisotropy (FA) and higher axial and radial diffusivity metrics in all callosal subregions. In both groups of children, lower FA and/or higher radial diffusivity in callosal subregions connecting anterior and posterior parietal cortical regions predicted poorer verbal WM, whereas higher radial diffusivity in callosal subregions connecting anterior and posterior parietal, as well as temporal, cortical regions predicted poorer visuospatial WM. DTI metrics, especially radial diffusivity, in predictive callosal subregions accounted for significant variance in WM over and above remaining callosal subregions. Reduced microstructural integrity of the CC, particularly in subregions connecting parietal and temporal cortices, may act as a neuropathological mechanism contributing to long-term WM deficits. The future clinical use of neuroanatomical biomarkers may allow for the early identification of children at highest risk for WM deficits and earlier provision of interventions for these children. PMID:23627735

  4. Segmentation and Analysis of Corpus Callosum in Alzheimer MR Images using Total Variation Based Diffusion Filter and Level Set Method.

    PubMed

    Anandh, K R; Sujatha, C M; Ramakrishnan, S

    2015-01-01

    Alzheimer’s Disease (AD) is a common form of dementia that affects gray and white matter structures of brain. Manifestation of AD leads to cognitive deficits such as memory impairment problems, ability to think and difficulties in performing day to day activities. Although the etiology of this disease is unclear, imaging biomarkers are highly useful in the early diagnosis of AD. Magnetic resonance imaging is an indispensible non-invasive imaging modality that reflects both the geometry and pathology of the brain. Corpus Callosum (CC) is the largest white matter structure as well as the main inter-hemispheric fiber connection that undergoes regional alterations due to AD. Therefore, segmentation and feature extraction are predominantly essential to characterize the CC atrophy. In this work, an attempt has been made to segment CC using edge based level set method. Prior to segmentation, the images are pre-processed using Total Variation (TV) based diffusion filtering to enhance the edge information. Shape based geometric features are extracted from the segmented CC images to analyze the CC atrophy. Results show that the edge based level set method is able to segment CC in both the normal and AD images. TV based diffusion filtering has performed uniform region specific smoothing thereby preserving the texture and small scale details of the image. Consequently, the edge map of CC in both the normal and AD are apparently sharp and distinct with continuous boundaries. This facilitates the final contour to correctly segment CC from the nearby structures. The extracted geometric features such as area, perimeter and minor axis are found to have the percentage difference of 5.97%, 22.22% and 9.52% respectively in the demarcation of AD subjects. As callosal atrophy is significant in the diagnosis of AD, this study seems to be clinically useful.

  5. Properties and fate of oligodendrocyte progenitor cells in the corpus callosum, motor cortex, and piriform cortex of the mouse.

    PubMed

    Clarke, Laura E; Young, Kaylene M; Hamilton, Nicola B; Li, Huiliang; Richardson, William D; Attwell, David

    2012-06-13

    Oligodendrocyte progenitor cells (OPCs) in the postnatal mouse corpus callosum (CC) and motor cortex (Ctx) reportedly generate only oligodendrocytes (OLs), whereas those in the piriform cortex may also generate neurons. OPCs have also been subdivided based on their expression of voltage-gated ion channels, ability to respond to neuronal activity, and proliferative state. To determine whether OPCs in the piriform cortex have inherently different physiological properties from those in the CC and Ctx, we studied acute brain slices from postnatal transgenic mice in which GFP expression identifies OL lineage cells. We whole-cell patch clamped GFP-expressing (GFP(+)) cells within the CC, Ctx, and anterior piriform cortex (aPC) and used prelabeling with 5-ethynyl-2'-deoxyuridine (EdU) to assess cell proliferation. After recording, slices were immunolabeled and OPCs were defined by strong expression of NG2. NG2(+) OPCs in the white and gray matter proliferated and coexpressed PDGFRα and voltage-gated Na(+) channels (I(Na)). Approximately 70% of OPCs were capable of generating regenerative depolarizations. In addition to OLIG2(+) NG2(+) I(Na)(+) OPCs and OLIG2(+) NG2(neg) I(Na)(neg) OLs, we identified cells with low levels of NG2 limited to the soma or the base of some processes. These cells had a significantly reduced I(Na) and a reduced ability to incorporate EdU when compared with OPCs and probably correspond to early differentiating OLs. By combining EdU labeling and lineage tracing using Pdgfrα-CreER(T2) : R26R-YFP transgenic mice, we double labeled OPCs and traced their fate in the postnatal brain. These OPCs generated OLs but did not generate neurons in the aPC or elsewhere at any time that we examined.

  6. Clinical outcomes and neurodevelopmental outcome of prenatally diagnosed agenesis of corpus callosum in single center of Korea

    PubMed Central

    Kim, Sung Eun; Jang, Hye-In; Chang, Kylie Hae-jin; Sung, Ji-Hee; Lee, Jiwon; Lee, Jeehun; Choi, Suk-Joo; Roh, Cheong-Rae; Kim, Jong-Hwa

    2017-01-01

    Objective With recent advances and frequent use of prenatal ultrasound, the antenatal diagnosis of agenesis of the corpus callosum (ACC) is not rare in obstetrics practices. However, information regarding the long-term neurological outcome remains uncertain. The aim of this study was to investigate clinical outcomes of prenatally diagnosed ACC and to analyze postnatal neurodevelopmental outcomes of ACC neonates born in our single center. Methods We retrospectively reviewed 56 cases of prenatally suspected ACC referred to our center. Results Fifty-six fetuses were diagnosed with ACC, and 12 of those were followed-up in our center until delivery. Of the remaining 44, 7 were delivered after being referred back to the original hospital, 23 were lost to follow-up, and 14 had unknown outcomes. Among all 56, 29 were considered to have isolated ACC and 27 were considered to have non-isolated ACC. Of the 10 live fetuses delivered in our center, four had isolated ACC, three had non-isolated ACC, and the rest had outcomes unrelated to ACC. Neurodevelopmental outcome was followed-up until approximately age 3 years. Of the four with isolated ACC, three (75%) had normal neurodevelopmental outcomes. Conclusion Similar to other studies, the results of our single-center study included positive neurodevelopmental outcomes for those with isolated ACC. However, despite our endeavor to counsel patients with prenatally diagnosed ACC, the delivery rate in our center was quite low. Therefore, larger, multicenter, retrospective studies including long-term neurological development outcomes are crucial and urgently needed to provide better counseling. PMID:28217666

  7. Corpus callosum area in patients with bipolar disorder with and without psychotic features: an international multicentre study

    PubMed Central

    Sarrazin, Samuel; d’Albis, Marc-Antoine; McDonald, Colm; Linke, Julia; Wessa, Michèle; Phillips, Mary; Delavest, Marine; Emsell, Louise; Versace, Amelia; Almeida, Jorge; Mangin, Jean-François; Poupon, Cyril; Le Dudal, Katia; Daban, Claire; Hamdani, Nora; Leboyer, Marion; Houenou, Josselin

    2015-01-01

    Background Previous studies have reported MRI abnormalities of the corpus callosum (CC) in patients with bipolar disorder (BD), although only a few studies have directly compared callosal areas in psychotic versus nonpsychotic patients with this disorder. We sought to compare regional callosal areas in a large international multicentre sample of patients with BD and healthy controls. Methods We analyzed anatomic T1 MRI data of patients with BD-I and healthy controls recruited from 4 sites (France, Germany, Ireland and the United States). We obtained the mid-sagittal areas of 7 CC subregions using an automatic CC delineation. Differences in regional callosal areas between patients and controls were compared using linear mixed models (adjusting for age, sex, handedness, brain volume, history of alcohol abuse/dependence, lithium or antipsychotic medication status, symptomatic status and site) and multiple comparisons correction. We also compared regional areas of the CC between patients with BD with and without a history of psychotic features. Results We included 172 patients and 146 controls in our study. Patients with BD had smaller adjusted mid-sagittal CC areas than controls along the posterior body, the isthmus and the splenium of the CC. Patients with a positive history of psychotic features had greater adjusted area of the rostral CC region than those without a history of psychotic features. Limitations We found small to medium effect sizes, and there was no calibration technique among the sites. Conclusion Our results suggest that BD with psychosis is associated with a different pattern of interhemispheric connectivity than BD without psychosis and could be considered a relevant neuroimaging subtype of BD. PMID:26151452

  8. Cuprizone demyelination of the corpus callosum in mice correlates with altered social interaction and impaired bilateral sensorimotor coordination.

    PubMed

    Hibbits, Norah; Pannu, Ravinder; Wu, T John; Armstrong, Regina C

    2009-08-14

    For studies of remyelination in demyelinating diseases, the cuprizone model of CC (corpus callosum) demyelination has experimental advantages that include overall size, proximity to neural stem cells of the subventricular zone, and correlation with a lesion predilection site in multiple sclerosis. In addition, cuprizone treatment can be ended to allow more direct analysis of remyelination than with viral or autoimmune models. However, CC demyelination lacks a useful functional correlate in rodents for longitudinal analysis throughout the course of demyelination and remyelination. In the present study, we tested two distinct behavioural measurements in mice fed 0.2% cuprizone. Running on a 'complex' wheel with varied rung intervals requires integration between cerebral hemispheres for rapid bilateral sensorimotor coordination. Maximum running velocity on the 'complex' wheel decreased during acute (6 week) and chronic (12 week) cuprizone demyelination. Running velocity on the complex wheel distinguished treated (for 6 weeks) from non-treated mice, even after a 6-week recovery period for spontaneous remyelination. A second behavioural assessment was a resident-intruder test of social interaction. The frequency of interactive behaviours increased among resident mice after acute or chronic demyelination. Differences in both sensorimotor coordination and social interaction correlated with demonstrated CC demyelination. The wheel assay is applicable for longitudinal studies. The resident-intruder assay provides a complementary assessment of a distinct modality at a specific time point. These behavioural measurements are sufficiently robust for small cohorts as a non-invasive assessment of demyelination to facilitate analysis of subsequent remyelination. These measurements may also identify CC involvement in other mouse models of central nervous system injuries and disorders.

  9. Negative Associations between Corpus Callosum Midsagittal Area and IQ in a Representative Sample of Healthy Children and Adolescents

    PubMed Central

    Ganjavi, Hooman; Lewis, John D.; Bellec, Pierre; MacDonald, Penny A.; Waber, Deborah P.; Evans, Alan C.; Karama, Sherif

    2011-01-01

    Documented associations between corpus callosum size and cognitive ability have heretofore been inconsistent potentially owing to differences in sample characteristics, differing methodologies in measuring CC size, or the use of absolute versus relative measures. We investigated the relationship between CC size and intelligence quotient (IQ) in the NIH MRI Study of Normal Brain Development sample, a large cohort of healthy children and adolescents (aged six to 18, n = 198) recruited to be representative of the US population. CC midsagittal area was measured using an automated system that partitioned the CC into 25 subregions. IQ was measured using the Wechsler Abbreviated Scale of Intelligence (WASI). After correcting for total brain volume and age, a significant negative correlation was found between total CC midsagittal area and IQ (r = −0.147; p = 0.040). Post hoc analyses revealed a significant negative correlation in children (age<12) (r = −0.279; p = 0.004) but not in adolescents (age≥12) (r = −0.005; p = 0.962). Partitioning the subjects by gender revealed a negative correlation in males (r = −0.231; p = 0.034) but not in females (r = 0.083; p = 0.389). Results suggest that the association between CC and intelligence is mostly driven by male children. In children, a significant gender difference was observed for FSIQ and PIQ, and in males, a significant age-group difference was observed for FSIQ and PIQ. These findings suggest that the correlation between CC midsagittal area and IQ may be related to age and gender. PMID:21625542

  10. The role of primary cilia in corpus callosum formation is mediated by production of the Gli3 repressor.

    PubMed

    Laclef, Christine; Anselme, Isabelle; Besse, Laurianne; Catala, Martin; Palmyre, Aurélien; Baas, Dominique; Paschaki, Marie; Pedraza, Maria; Métin, Christine; Durand, Bénédicte; Schneider-Maunoury, Sylvie

    2015-09-01

    Agenesis of the corpus callosum (AgCC) is a frequent brain disorder found in over 80 human congenital syndromes including ciliopathies. Here, we report a severe AgCC in Ftm/Rpgrip1l knockout mouse, which provides a valuable model for Meckel-Grüber syndrome. Rpgrip1l encodes a protein of the ciliary transition zone, which is essential for ciliogenesis in several cell types in mouse including neuroepithelial cells in the developing forebrain. We show that AgCC in Rpgrip1l(-/-) mouse is associated with a disturbed location of guidepost cells in the dorsomedial telencephalon. This mislocalization results from early patterning defects and abnormal cortico-septal boundary (CSB) formation in the medial telencephalon. We demonstrate that all these defects primarily result from altered GLI3 processing. Indeed, AgCC, together with patterning defects and mispositioning of guidepost cells, is rescued by overexpressing in Rpgrip1l(-/-) embryos, the short repressor form of the GLI3 transcription factor (GLI3R), provided by the Gli3(Δ699) allele. Furthermore, Gli3(Δ699) also rescues AgCC in Rfx3(-/-) embryos deficient for the ciliogenic RFX3 transcription factor that regulates the expression of several ciliary genes. These data demonstrate that GLI3 processing is a major outcome of primary cilia function in dorsal telencephalon morphogenesis. Rescuing CC formation in two independent ciliary mutants by GLI3(Δ699) highlights the crucial role of primary cilia in maintaining the proper level of GLI3R required for morphogenesis of the CC.

  11. Response inhibition deficits in children with Fetal Alcohol Spectrum Disorder: Relationship between diffusion tensor imaging of the corpus callosum and eye movement control

    PubMed Central

    Paolozza, Angelina; Treit, Sarah; Beaulieu, Christian; Reynolds, James N.

    2014-01-01

    Response inhibition is the ability to suppress irrelevant impulses to enable goal-directed behavior. The underlying neural mechanisms of inhibition deficits are not clearly understood, but may be related to white matter connectivity, which can be assessed using diffusion tensor imaging (DTI). The goal of this study was to investigate the relationship between response inhibition during the performance of saccadic eye movement tasks and DTI measures of the corpus callosum in children with or without Fetal Alcohol Spectrum Disorder (FASD). Participants included 43 children with an FASD diagnosis (12.3 ± 3.1 years old) and 35 typically developing children (12.5 ± 3.0 years old) both aged 7–18, assessed at three sites across Canada. Response inhibition was measured by direction errors in an antisaccade task and timing errors in a delayed memory-guided saccade task. Manual deterministic tractography was used to delineate six regions of the corpus callosum and calculate fractional anisotropy (FA), mean diffusivity (MD), parallel diffusivity, and perpendicular diffusivity. Group differences in saccade measures were assessed using t-tests, followed by partial correlations between eye movement inhibition scores and corpus callosum FA and MD, controlling for age. Children with FASD made more saccade direction errors and more timing errors, which indicates a deficit in response inhibition. The only group difference in DTI metrics was significantly higher MD of the splenium in FASD compared to controls. Notably, direction errors in the antisaccade task were correlated negatively to FA and positively to MD of the splenium in the control, but not the FASD group, which suggests that alterations in connectivity between the two hemispheres of the brain may contribute to inhibition deficits in children with FASD. PMID:24967159

  12. Self-referential and social cognition in a case of autism and agenesis of the corpus callosum

    PubMed Central

    2012-01-01

    Background While models of autism spectrum conditions (ASC) are emerging at the genetic level of analysis, clear models at higher levels of analysis, such as neuroanatomy, are lacking. Here we examine agenesis of the corpus callosum (AgCC) as a model at the level of neuroanatomy that may be relevant for understanding self-referential and social-cognitive difficulties in ASC. Methods We examined performance on a wide array of tests in self-referential and social-cognitive domains in a patient with both AgCC and a diagnosis of ASC. Tests included a depth-of-processing memory paradigm with self-referential and social-cognitive manipulations, self-report measures of self-consciousness, alexithymia, and empathy, as well as performance measures of first-person pronoun usage and mentalizing ability. The performance of the AgCC patient was compared to a group of individuals with ASC but without AgCC and with neurotypical controls. These comparison groups come from a prior study where group differences were apparent across many measures. We used bootstrapping to assess whether the AgCC patient exhibited scores that were within or outside the 95% bias-corrected and accelerated bootstrap confidence intervals observed in both comparison groups. Results Within the depth-of-processing memory paradigm, the AgCC patient showed decreased memory sensitivity that was more extreme than both comparison groups across all conditions. The patient’s most pronounced difficulty on this task emerged in the social-cognitive domain related to information-processing about other people. The patient was similar to the ASC group in benefiting less from self-referential processing compared to the control group. Across a variety of other self-referential (i.e. alexithymia, private self-consciousness) and social-cognitive measures (i.e. self-reported imaginative and perspective-taking subscales of empathy, mentalizing), the AgCC patient also showed more extreme scores than those observed for both of

  13. The gene responsible for a severe form of peripheral neuropathy and agenesis of the corpus callosum maps to chromosome 15q

    SciTech Connect

    Casaubon, L.K.; Melanson, M.; Marineau, C. |

    1996-01-01

    Peripheral neuropathy with or without agenesis of the corpus callosum (ACCPN) is a devastating neurodegenerative disorder that is transmitted as an autosomal recessive trait. Genealogical studies in a large number of affected French Canadian individuals suggest that ACCPN results from a single founder mutation. A genomewide search using 120 microsatellite DNA markers in 14 French Canadian families allowed the mapping of the ACCPN gene to a 5-cM region on chromosome 15q13-q15 that is flanked by markers D15S1040 and D15S118. A maximum two-point LOD score of 11.1 was obtained with the marker D15S971 at a recombination fraction of 0. Haplotype analysis and linkage disequilibrium support a founder effect. These findings are the first step in the identification of the gene responsible for ACCPN, which may shed some light on the numerous conditions associated with progressive peripheral neuropathy or agenesis of the corpus callosum. 28 refs., 2 figs., 3 tabs.

  14. The gene responsible for a severe form of peripheral neuropathy and agenesis of the corpus callosum maps to chromosome 15q.

    PubMed Central

    Casaubon, L. K.; Melanson, M.; Lopes-Cendes, I.; Marineau, C.; Andermann, E.; Andermann, F.; Weissenbach, J.; Prévost, C.; Bouchard, J. P.; Mathieu, J.; Rouleau, G. A.

    1996-01-01

    Peripheral neuropathy with or without agenesis of the corpus callosum (ACCPN) is a devastating neurodegenerative disorder that is transmitted as an autosomal recessive trait. Genealogical studies in a large number of affected French Canadian individuals suggest that ACCPN results from a single founder mutation. A genomewide search using 120 microsatellite DNA markers in 14 French Canadian families allowed the mapping of the ACCPN gene to a 5-cM region on chromosome 15q13-q15 that is flanked by markers D15S1040 and D15S118. A maximum two-point LOD score of 11.1 was obtained with the marker D15S971 at a recombination fraction of 0. Haplotype analysis and linkage disequilibrium support a founder effect. These findings are the first step in the identification of the gene responsible for ACCPN, which may shed some light on the numerous conditions associated with the progressive peripheral neuropathy or agenesis of the corpus callosum. PMID:8554065

  15. [Neuropsychological studies of two subjects after the transection of the splenium of the corpus callosum. (Part 2. The auditory recognition by the dichotic listening test) (author's transl)].

    PubMed

    Watanabe, S; Hojo, K; Sato, T; Tanaka, T; Watanabe, K; Yoshimura, I

    1979-10-01

    We made the neuropsychological auditory studies of two right-handed subjects who had undergone the transection of the splenium of the corpus callosum for the pineal operation (the teratoma by the histopathological examination). The transection grades were 2.0 cm and 2.5 cm. The truncus and splenium of the second subject were flat by the compression of the tumor. We examined these subjects by the some audiolocigal methods. 1. Pure tone audiometry. 2. Fixed frequency Békésy audiometry. 3. SISI test (short increment sensitivity index test). 4. Speech audiometry. 5. Distorted speech test (filtered speech test). 6. Binaural fusion test. 7. Dichotic listening test. The tasks used for the dichotic listening test were following. Different digits (one pair, three pairs), different words (from two to four syllables) and different vowels and consonants were presented simultaneously to the two ears by means of a dual-channel tape recorder with stereophonic earphone. The result shows that the first subject (whose section of the spelenium was 2.0 cm) shows a slight but not significant superiority on the right ear to the one pair digits and words (p less than 0.1), and the second subject (whose section of the splenium was 2.5 cm and whose splenium and truncus of the corpus callusum were flatten by the compression of the tumor) shows a significant superiority on the right ear to the one pair digits, words, three pairs digits and vowels (p less than 0.05). But there was no definitive abnormalities at the pure tone audiometry, the fixed frequency Békésy audiometry, SISI test, distorted speech test and binaural fusion test of two cases. The result shows that the commissure fibres of the auditory perception of the speech of two hemispheres connect through from splenium to the truncus of the corpus callosum.

  16. Diffusion tensor quantification and cognitive correlates of the macrostructure and microstructure of the corpus callosum in typically developing and dyslexic children.

    PubMed

    Hasan, Khader M; Molfese, David L; Walimuni, Indika S; Stuebing, Karla K; Papanicolaou, Andrew C; Narayana, Ponnada A; Fletcher, Jack M

    2012-11-01

    Noninvasive quantitative MRI methods, such as diffusion tensor imaging (DTI), can offer insights into the structure-function relationships in human developmental brain disorders. In this article, we quantified the macrostructural and microstructural attributes of the corpus callosum (CC) in children with dyslexia and in typically developing readers of comparable age and gender. Diffusion anisotropy, and mean, radial and axial diffusivities of cross-sectional CC subregions were computed using a validated DTI methodology. The normalized posterior CC area was enlarged in children with dyslexia relative to that in typically developing children. Moreover, the callosal microstructural attributes, such as the mean diffusivity of the posterior middle sector of the CC, correlated significantly with measures of word reading and reading comprehension. Reading group differences in fractional anisotropy, mean diffusivity and radial diffusivity were observed in the posterior CC (CC5). This study demonstrates the utility of regional DTI measurements of the CC in understanding the neurobiology of reading disorders.

  17. Gelastic epilepsy in combination with hypothalamic hamartoma and partial agenesis of the corpus callosum: A case report and review of the literature.

    PubMed

    Cheng, Bochao; Sun, Chongran; Li, Shiguang; Gong, Qiyong; Lui, Su

    2013-12-01

    Gelastic epilepsy has been reported to originate from various conditions, particularly from hypothalamic hamartoma (HH). In the present study, we report a patient with gelastic seizures (GSs), followed by complex partial and tonic-clonic seizures. Magnetic resonance imaging (MRI) revealed a rare combination of HH and partial agenesis of the corpus callosum (ACC). Following resectioning of the HH, the seizures were reduced, but not fully controlled, with medication by the one year follow-up. HH and partial ACC patients may experience seizures; the seizures in the case presented in this study may have originated from HH, partial ACC or both. Considering the fact that seizure frequency reduced following surgery, they may have mainly occurred from HH. Additionally it was considered to be likely that the seizures following surgery were due to secondary epileptogenesis, partial ACC, or both.

  18. Gelastic epilepsy in combination with hypothalamic hamartoma and partial agenesis of the corpus callosum: A case report and review of the literature

    PubMed Central

    CHENG, BOCHAO; SUN, CHONGRAN; LI, SHIGUANG; GONG, QIYONG; LUI, SU

    2013-01-01

    Gelastic epilepsy has been reported to originate from various conditions, particularly from hypothalamic hamartoma (HH). In the present study, we report a patient with gelastic seizures (GSs), followed by complex partial and tonic-clonic seizures. Magnetic resonance imaging (MRI) revealed a rare combination of HH and partial agenesis of the corpus callosum (ACC). Following resectioning of the HH, the seizures were reduced, but not fully controlled, with medication by the one year follow-up. HH and partial ACC patients may experience seizures; the seizures in the case presented in this study may have originated from HH, partial ACC or both. Considering the fact that seizure frequency reduced following surgery, they may have mainly occurred from HH. Additionally it was considered to be likely that the seizures following surgery were due to secondary epileptogenesis, partial ACC, or both. PMID:24255688

  19. A case of ring chromosome 22 with deletion of the 22q13.3 region associated with agenesis of the corpus callosum, fornix and septum pellucidum.

    PubMed

    Delcán, José; Orera, María; Linares, Rafael; Saavedra, Dolores; Palomar, Angustias

    2004-08-01

    We report a 16-week-gestation foetus obtained by voluntary abortion after prenatal diagnosis, in which a ring chromosome 22 was observed with deletion of the 22q13.3 region. A prenatal study of the amniotic fluid by standard chromosome technique with G bands and FISH (fluorescence in situ hybridisation) was performed. After the abortion, the anatomopathological study of the obtained foetus was carried out. Morphological and histological analysis of the foetus did not reveal severe physical abnormalities, although alterations of the nervous system were observed consisting of corpus callosum, fornix and septum pellucidum agenesia. It could be that the genes in this region that were involved in the development of the central nervous system were responsible for the alterations found in the morphological study. The wide range of manifestations observed in patients with this cytogenetic alteration is probably due to size differences in the deleted region.

  20. Diffusion Tensor Quantification and Cognitive Correlates of the Macrostructure and Microstructure of the Corpus Callosum in Typically Developing Children and Dyslexics

    PubMed Central

    Hasan, Khader M.; Molfese, David L.; Walimuni, Indika S.; Stuebing, Karla K.; Papanicolaou, Andrew C.; Narayana, Ponnada A.; Fletcher, Jack M.

    2012-01-01

    Noninvasive quantitative magnetic resonance imaging methods such as diffusion tensor imaging (DTI), can offer insights into structure/function relationships in human developmental brain disorders. In this report, we quantified macrostructural and microstructural attributes of the corpus callosum (CC) in children with dyslexia and typically developing readers of comparable age and gender. Diffusion anisotropy, mean, radial and axial diffusivities of cross-sectional CC sub-regions were computed using a validated DTI methodology. The normalized posterior CC area was enlarged in children with dyslexia compared to typically developing children. Moreover, the callosal microstructural attributes, such as mean diffusivity of the posterior middle sector of the CC, significantly correlated with measures of word reading and reading comprehension. Reading group differences in FA, MD, and RD were observed in the posterior CC (CC5). This study demonstrates the utility of regional DTI measurements of the CC in understanding the neurobiology of reading disorders. PMID:22411286

  1. Software pipeline for midsagittal corpus callosum thickness profile processing : automated segmentation, manual editor, thickness profile generator, group-wise statistical comparison and results display.

    PubMed

    Adamson, Chris; Beare, Richard; Walterfang, Mark; Seal, Marc

    2014-10-01

    This paper presents a fully automated pipeline for thickness profile evaluation and analysis of the human corpus callosum (CC) in 3D structural T 1-weighted magnetic resonance images. The pipeline performs the following sequence of steps: midsagittal plane extraction, CC segmentation algorithm, quality control tool, thickness profile generation, statistical analysis and results figure generator. The CC segmentation algorithm is a novel technique that is based on a template-based initialisation with refinement using mathematical morphology operations. The algorithm is demonstrated to have high segmentation accuracy when compared to manual segmentations on two large, publicly available datasets. Additionally, the resultant thickness profiles generated from the automated segmentations are shown to be highly correlated to those generated from the ground truth segmentations. The manual editing tool provides a user-friendly environment for correction of errors and quality control. Statistical analysis and a novel figure generator are provided to facilitate group-wise morphological analysis of the CC.

  2. Abnormal corpus callosum connectivity, socio-communicative deficits, and motor deficits in children with autism spectrum disorder: a diffusion tensor imaging study.

    PubMed

    Hanaie, Ryuzo; Mohri, Ikuko; Kagitani-Shimono, Kuriko; Tachibana, Masaya; Matsuzaki, Junko; Watanabe, Yoshiyuki; Fujita, Norihiko; Taniike, Masako

    2014-09-01

    In addition to social and communicative deficits, many studies have reported motor deficits in autism spectrum disorder (ASD). This study investigated the macro and microstructural properties of the corpus callosum (CC) of 18 children with ASD and 12 typically developing controls using diffusion tensor imaging tractography. We aimed to explore whether abnormalities of the CC were related to motor deficits, as well as social and communication deficits in children with ASD. The ASD group displayed abnormal macro and microstructure of the total CC and its subdivisions and its structural properties were related to socio-communicative deficits, but not to motor deficits in ASD. These findings advance our understanding of the contributions of the CC to ASD symptoms.

  3. CXCL12/CXCR4 Axis Improves Migration of Neuroblasts Along Corpus Callosum by Stimulating MMP-2 Secretion After Traumatic Brain Injury in Rats.

    PubMed

    Mao, Weifeng; Yi, Xin; Qin, Jianbing; Tian, Meiling; Jin, Guohua

    2016-06-01

    To investigate the effect of CXCL12 on migration of neural precursor cells after traumatic brain injury (TBI). We randomly divided 48 rats into four groups: (1) the sham group, rats were performed craniotomy only, (2) the control group, saline were injected into the ipsilateral cortex after TBI, (3) the CXCL12 group, CXCL12 were injected into the ipsilateral cortex after TBI, and (4) the CXCL12 + AMD3100 group, CXCL12 and AMD3100 were mixed together and injected into the ipsilateral cortex after TBI. At 7 days after TBI, the brain tissues were subjected to immunofluorescent double-labeled staining with the antibodies of CXCR4/DCX, MMP-2/DCX, MMP-2/GFAP, MMP-2/NeuN. Western blot assay was used to measure the protein levels of MMP-2. Compared with the control group, the number of CXCR4/DCX and MMP-2 positive cells around the injured corpus callosum area were significantly increased in the CXCL12 treatment group. The area occupied by these cells expanded and the shape changed from chain distribution to radial. CXCL12 + AMD3100 treatment significantly decreased the number and distribution area of CXCR4/DCX and MMP-2 positive cells compared with the CXCL12 treatment and control group. The DCX positive cells could not form chain or radial distribution. The protein expressions of MMP-2 had the similar change trends as the results of immunofluorescent staining. MMP-2 could be secreted by DCX, GFAP and NeuN positive cells. CXCL12/CXCR4 axis can improve the migration of the neuroblasts along the corpus callosum by stimulating the MMP-2 secretion of different types of cells.

  4. Structural abnormalities of corpus callosum and cortical axonal tracts accompanied by decreased anxiety-like behavior and lowered sociability in spock3- mutant mice.

    PubMed

    Yamamoto, Ayako; Uchiyama, Koji; Nara, Tomoka; Nishimura, Naomichi; Hayasaka, Michiko; Hanaoka, Kazunori; Yamamoto, Tatsuro

    2014-01-01

    Spock3/Testican-3 is a nervous system-expressed heparan sulfate proteoglycan belonging to a subgroup of the BM-40/SPARC/osteonectin family, the role of which in brain development is unclear. Because Spock1, a member of the Spock family, inhibits their attachment to substrates and the neurite outgrowth of cultured neuronal cells, Spock3 is also thought to be similarly involved in the neuronal development. In the present study, we established a Spock3-mutant mouse harboring a deletion extending from the presumptive upstream regulatory region to exon 4 of the Spock3 locus and performed histological and behavioral studies on these mutant mice. In wild-type (WT) mice, all Spock members were clearly expressed during brain development. In adults, intense Spock1 and Spock2 expressions were observed throughout the entire brain; whereas, Spock3 expression was no longer visible except in the thalamic nuclei. Thus, Spock3 expression is mostly confined to the developmental stage of the brain. In adult mutant mice, the cells of all cortical layers were swollen. The corpus callosum was narrowed around the central region along the rostral-caudal axis and many small spaces were observed without myelin sheaths throughout the entire corpus callosum. In addition, the cortical input and output fibers did not form into thick bundled fibers as well as the WT counterparts did. Moreover, a subpopulation of corticospinal axonal fibers penetrated into the dorsal striatum with moderately altered orientations. Consistent with these modifications of brain structures, the mutant mice exhibited decreased anxiety-like behavior and lowered sociability. Together, these results demonstrate that Spock3 plays an important role in the formation or maintenance of major neuronal structures in the brain.

  5. Yokukansan normalizes glucocorticoid receptor protein expression in oligodendrocytes of the corpus callosum by regulating microRNA-124a expression after stress exposure.

    PubMed

    Shimizu, Shoko; Tanaka, Takashi; Tohyama, Masaya; Miyata, Shingo

    2015-05-01

    Stressful events are known to down-regulate expression levels of glucocorticoid receptors (GRs) in the brain. Recently, we reported that stressed mice with elevated plasma levels of corticosterone exhibit morphological changes in the oligodendrocytes of nerve fiber bundles, such as those in the corpus callosum. However, little is known about the molecular mechanism of GR expression regulation in oligodendrocytes after stress exposure. A previous report has suggested that GR protein levels might be regulated by microRNA (miR)-18 and/or -124a in the brain. In this study, we aimed to elucidate the GR regulation mechanism in oligodendrocytes and evaluate the effects of yokukansan (YKS), a Kampo medicine, on GR protein regulation. Acute exposure to stress increased plasma corticosterone levels, decreased GR protein expression, and increased miR-124a expression in the corpus callosum of adult male mice, though the GR mRNA and miR-18 expression levels were not significant changes. YKS normalized the stress-induced changes in the plasma corticosterone, GR protein, and miR124a expression levels. An oligodendrocyte primary culture study also showed that YKS down-regulated miR-124a, but not miR-18, expression levels in dexamethasone-treated cells. These results suggest that the down-regulation of miR124a expression might be involved in the normalization of stress-induced decreases in GR protein in oligodendrocytes by YKS. This effect may imply the molecular mechanisms underlying the ameliorative effects of YKS on psychological symptoms and stress-related behaviors.

  6. Gross morphology and morphometric sequelae in the hippocampus, fornix, and corpus callosum of patients with severe non-missile traumatic brain injury without macroscopically detectable lesions: a T1 weighted MRI study

    PubMed Central

    Tomaiuolo, F; Carlesimo, G; Di, P; Petrides, M; Fera, F; Bonanni, R; Formisano, R; Pasqualetti, P; Caltagirone, C

    2004-01-01

    Objective: The gross morphology and morphometry of the hippocampus, fornix, and corpus callosum in patients with severe non-missile traumatic brain injury (nmTBI) without obvious neuroradiological lesions was examined and the volumes of these structures were correlated with performance on memory tests. In addition, the predictability of the length of coma from the selected anatomical volumes was examined. Method: High spatial resolution T1 weighted MRI scans of the brain (1 mm3) and neuropsychological evaluations with standardised tests were performed at least 3 months after trauma in 19 patients. Results: In comparison with control subjects matched in terms of gender and age, volume reduction in the hippocampus, fornix, and corpus callosum of the nmTBI patients was quantitatively significant. The length of coma correlated with the volume reduction in the corpus callosum. Immediate free recall of word lists correlated with the volume of the fornix and the corpus callosum. Delayed recall of word lists and immediate recall of the Rey figure both correlated with the volume of the fornix. Delayed recall of the Rey figure correlated with the volume of the fornix and the right hippocampus. Conclusion: These findings demonstrate that in severe nmTBI without obvious neuroradiological lesions there is a clear hippocampal, fornix, and callosal volume reduction. The length of coma predicts the callosal volume reduction, which could be considered a marker of the severity of axonal loss. A few memory test scores correlated with the volumes of the selected anatomical structures. This relationship with memory performance may reflect the diffuse nature of the damage, leading to the disruption of neural circuits at multiple levels and the progressive neural degeneration occurring in TBI. PMID:15314123

  7. A new locus (SPG47) maps to 1p13.2-1p12 in an Arabic family with complicated autosomal recessive hereditary spastic paraplegia and thin corpus callosum.

    PubMed

    Blumkin, Lubov; Lerman-Sagie, Tally; Lev, Dorit; Yosovich, Keren; Leshinsky-Silver, Esther

    2011-06-15

    The hereditary spastic paraplegias (HSP) are a heterogeneous group of genetic neurodegenerative disorders in which the main feature is progressive spasticity of the lower limbs due to pyramidal tract dysfunction. Clinically HSP are divided into two forms: a pure form that presents with progressive lower limb spasticity and weakness, sensory signs and bladder dysfunction, and a complicated form, associated with more extensive neurological and extra neurological signs as well as pathological findings on brain imaging. The clinical variability observed in HSP is supported by the large underlying genetic heterogeneity. Hereditary spastic paraplegia with thin corpus callosum (HSP-TCC) is a frequent subtype of complicated HSP clinically characterized by a slowly progressive spastic paraparesis with cognitive impairment and thin corpus callosum (TCC). SPG11, the most frequent gene associated with HSP-TCC, encodes spatacsin, a protein of unknown function. We describe two siblings from an Arabic consanguineous family with slowly progressive spastic paraparesis, mental retardation, seizures, thin corpus callosum and periventricular white matter abnormalities. Homozygosity mapping identified a novel single candidate region of 7.3 Mb on chromosome 1p13.2-1p12. The finding of a new locus for AR-HSP-TCC further demonstrates the extensive genetic heterogeneity of this condition.

  8. Sex-related difference in human white matter volumes studied: Inspection of the corpus callosum and other white matter by VBM

    PubMed Central

    Shiino, Akihiko; Chen, Yen-wei; Tanigaki, Kenji; Yamada, Atsushi; Vigers, Piers; Watanabe, Toshiyuki; Tooyama, Ikuo; Akiguchi, Ichiro

    2017-01-01

    It has been contended that any observed difference of the corpus callosum (CC) size between men and women is not sex-related but brain-size-related. A recent report, however, showed that the midsagittal CC area was significantly larger in women in 37 brain-size-matched pairs of normal young adults. Since this constituted strong evidence of sexual dimorphism and was obtained from publicly available data in OASIS, we examined volume differences within the CC and in other white matter using voxel-based morphometry (VBM). We created a three-dimensional region of interest of the CC and measured its volume. The VBM statistics were analyzed by permutation test and threshold-free cluster enhancement (TFCE) with the significance levels at FWER < 0.05. The CC volume was significantly larger in women in the same 37 brain-size-matched pairs. We found that the CC genu was the subregion showing the most significant sex-related difference. We also found that white matter in the bilateral anterior frontal regions and the left lateral white matter near to Broca’s area were larger in women, whereas there were no significant larger regions in men. Since we used brain-size-matched subjects, our results gave strong volumetric evidence of localized sexual dimorphism of white matter. PMID:28045130

  9. [Left-sided metamorphopsia of the face and simple objects caused by an infarction at the right side of the splenium of the corpus callosum].

    PubMed

    Nagaishi, Akiko; Narita, Tomoko; Gondo, Yuichiro; Nakane, Shunya; Fukudome, Takayasu; Matsuo, Hidenori

    2015-01-01

    A 78-year-old woman noticed that people's eyes and the right nasal foramens located in her left visual field looked smaller than those observed in the right. The woman reported no change in shape regarding facial outlines or scenic objects. Magnetic resonance imaging revealed an acute infarction of the right side of the splenium of the corpus callosum. Close examination revealed that her metamorphopsia affected the left side of her visual field, especially influencing facial components, particularly the eye. The woman had similar reactions to photographs of several kinds of animals, realistic portraits of humans, and caricatured humans. Meanwhile, presentings caricature human face at a 90° rotation elicited metamorphopsia in eyebrows located on the left side of a picture, but not the eyes. She also reported a change of shape or color tone for geometric objects. The patient's only symptom was metamorphopsia, and she did not show any other neurological defects such as callosal disconnection syndrome. Furthermore, objects that were affected by the patient's metamorphopsia (e.g. facial component especially the eye, and simple geometric figures) may be easy images to use in order to detect this type of distorted vision.

  10. Adult-onset deficiency in growth hormone and insulin-like growth factor-I alters oligodendrocyte turnover in the corpus callosum.

    PubMed

    Hua, Kun; Forbes, M Elizabeth; Lichtenwalner, Robin J; Sonntag, William E; Riddle, David R

    2009-08-01

    Growth hormone (GH) and insulin-like growth factor-I (IGF-I) provide trophic support during development and also appear to influence cell structure, function and replacement in the adult brain. Recent studies demonstrated effects of the GH/IGF-I axis on adult neurogenesis, but it is unclear whether the GH/IGF-I axis influences glial turnover in the normal adult brain. In the current study, we used a selective model of adult-onset GH and IGF-I deficiency to evaluate the role of GH and IGF-I in regulating glial proliferation and survival in the adult corpus callosum. GH/IGF-I-deficient dwarf rats of the Lewis strain were made GH/IGF-I replete via twice daily injections of GH starting at postnatal day 28 (P28), approximately the age at which GH pulse amplitude increases in developing rodents. GH/IGF-I deficiency was initiated in adulthood by removing animals from GH treatment. Quantitative analyses revealed that adult-onset GH/IGF-I deficiency decreased cell proliferation in the white matter and decreased the survival of newborn oligodendrocytes. These findings are consistent with the hypothesis that aging-related changes in the GH/IGF-I axis produce deficits in ongoing turnover of oligodendrocytes, which may contribute to aging-related cognitive changes and deficits in remyelination after injury.

  11. Comparison between skeleton-based and atlas-based approach in the assessment of corpus callosum damages in Mild Cognitive Impairment and Alzheimer Disease.

    PubMed

    Preti, Maria Giulia; Laganà, Maria Marcella; Baglio, Francesca; Griffanti, Ludovica; Nemni, Raffaello; Cecconi, Pietro; Baselli, Giuseppe

    2011-01-01

    The damage of specific bundles in the brain white matter (WM) is currently assessed in Alzheimer Disease (AD) and amnestic Mild Cognitive Impairment (aMCI) by tractography based on diffusion tensor imaging (DTI) and the consequent evaluation of diffusion parameters in reconstructed tracts. Controversial results may be due to the use of different techniques. This work aims at comparing an atlas-based technique to compute fractional anisotropy (FA) in specific tracts with the voxelwise approach of Tract-Based Spatial Statistics (TBSS). FA was evaluated in 7 portions of the corpus callosum (CC) of 10 elderly healthy controls (HC), 10 aMCI and 10 mild AD patients with both approaches. Atlas-based tractography revealed concordant results with TBSS, displaying the same significant differences between AD and HC and no significant difference between aMCI and HC. However, as regards the AD to aMCI contrast only the atlas-based method was able to find significantly lowered FA in AD in frontal and parietal CC portions. This finding shows that a proper analysis which considers a higher number of voxels, not restricting the observation to the skeleton in the assessment of CC damages, could be useful for AD to aMCI differential diagnosis and prognosis.

  12. Mirror Motor Activity During Right-Hand Contractions and Its Relation to White Matter in the Posterior Midbody of the Corpus Callosum.

    PubMed

    Sehm, Bernhard; Steele, Christoper J; Villringer, Arno; Ragert, Patrick

    2015-09-22

    Cortical activity during simple unimanual actions is typically lateralized to contralateral sensorimotor areas, while a more bilateral pattern is observed with an increase in task demands. In parallel, increasing task demands are associated with subtle mirror muscle activity in the resting hand, implying a relative loss in motor selectivity. The corpus callosum (CC) is crucially involved in unimanual tasks by mediating both facilitatory and inhibitory interactions between bilateral motor cortical systems, but its association with mirror motor activity is yet unknown. Here, we used diffusion-weighted imaging and bilateral electromyographic (EMG) measurements during a unimanual task to investigate potential relationships between white matter microstructure of the CC and mirror EMG activity. Participants performed an unimanual pinch force task with both hands alternatively. Four parametrically increasing force levels were exerted while EMG activity was recorded bilaterally from first dorsal interosseus muscles. Consistent with previous findings, mirror EMG activity increased as a function of force. Additionally, there was a significant relationship between the slope of increasing mirror EMG during right-hand contractions and fractional anisotropy in transcallosal fibers connecting both M1. No significant relationships were found for fibers connecting dorsal premotor cortices or supplementary motor area, indicating the local specificity of the observed brain-physiology relationship.

  13. 3D pre- versus post-season comparisons of surface and relative pose of the corpus callosum in contact sport athletes

    NASA Astrophysics Data System (ADS)

    Lao, Yi; Gajawelli, Niharika; Haas, Lauren; Wilkins, Bryce; Hwang, Darryl; Tsao, Sinchai; Wang, Yalin; Law, Meng; Leporé, Natasha

    2014-03-01

    Mild traumatic brain injury (MTBI) or concussive injury affects 1.7 million Americans annually, of which 300,000 are due to recreational activities and contact sports, such as football, rugby, and boxing[1]. Finding the neuroanatomical correlates of brain TBI non-invasively and precisely is crucial for diagnosis and prognosis. Several studies have shown the in influence of traumatic brain injury (TBI) on the integrity of brain WM [2-4]. The vast majority of these works focus on athletes with diagnosed concussions. However, in contact sports, athletes are subjected to repeated hits to the head throughout the season, and we hypothesize that these have an influence on white matter integrity. In particular, the corpus callosum (CC), as a small structure connecting the brain hemispheres, may be particularly affected by torques generated by collisions, even in the absence of full blown concussions. Here, we use a combined surface-based morphometry and relative pose analyses, applying on the point distribution model (PDM) of the CC, to investigate TBI related brain structural changes between 9 pre-season and 9 post-season contact sport athlete MRIs. All the data are fed into surface based morphometry analysis and relative pose analysis. The former looks at surface area and thickness changes between the two groups, while the latter consists of detecting the relative translation, rotation and scale between them.

  14. Stereotactic linac-based radiosurgery in the treatment of cerebral arteriovenous malformations located deep, involving corpus callosum, motor cortex, or brainstem

    SciTech Connect

    Zabel-du Bois, Angelika . E-mail: A.Zabel@dkfz-heidelberg.de; Milker-Zabel, Stefanie; Huber, Peter; Schlegel, Wolfgang; Debus, Juergen

    2006-03-15

    Purpose: To evaluate patient outcome and obliteration rates after radiosurgery (RS) for cerebral arteriovenous malformations (AVM) located deep, in the motor cortex or brainstem and those involving corpus callosum. Methods and Materials: This analysis is based on 65 patients. AVM classification according to Spetzler-Martin was 13 patients Grade 2, 39 Grade 3, 12 Grade 4, and 1 Grade 5. Median RS-based AVM score was 1.69. Median single dose was 18 Gy. Mean treatment volume was 5.2 cc (range, 0.2-26.5 cc). Forty patients (62%) experienced intracranial hemorrhage before RS. Median follow-up was 3.0 years. Results: Actuarial complete obliteration rate (CO) was 50% and 65% after 3 and 5 years, respectively. CO was significantly higher in AVM <3 cm (p < 0.02) and after doses >18 Gy (p < 0.009). Annual bleeding risk after RS was 4.7%, 3.4%, and 2.7% after 1, 2, and 3 years, respectively. AVM >3 cm (p < 0.01), AVM volume >4 cc (p < 0.009), and AVM score >1.5 (p < 0.02) showed a significant higher bleeding risk. Neurologic dysfunction improved, completely dissolved, or remained stable in 94% of patients. Conclusions: Surgically inaccessible AVM can be successfully treated using RS with acceptable obliteration rates and low risk for late morbidity. The risk of intracranial hemorrhage is reduced after RS and depends on RS-based AVM score.

  15. Calcium, potassium, iron, copper and zinc concentrations in the white and gray matter of the cerebellum and corpus callosum in brain of four genetic mouse strains

    NASA Astrophysics Data System (ADS)

    Sergeant, C.; Vesvres, M. H.; Devès, G.; Guillou, F.

    2005-04-01

    In the central nervous system, metallic cations are involved in oligodendrocyte maturation and myelinogenesis. Moreover, the metallic cations have been associated with pathogenesis, particularly multiple sclerosis and malignant gliomas. The brain is vulnerable to either a deficit or an excess of available trace elements. Relationship between trace metals and myelinogenesis is important in understanding a severe human pathology : the multiple sclerosis, which remains without efficient treatment. One approach to understand this disease has used mutant or transgenic mice presenting myelin deficiency or excess. But to date, the concentration of trace metals and mineral elements in white and gray matter areas in wild type brain is unknown. The aim of this study is to establish the reference concentrations of trace metals (iron, copper and zinc) and minerals (potassium and calcium) in the white and gray matter of the mouse cerebellum and corpus callosum. The brains of four different genetic mouse strains (C57Black6/SJL, C57Black6/D2, SJL and C3H) were analyzed. The freeze-dried samples were prepared to allow PIXE (Proton-induced X-ray emission) and RBS (Rutherford backscattering spectrometry) analyses with the nuclear microprobe in Bordeaux. The results obtained give the first reference values. Furthermore, one species out of the fours testes exhibited differences in calcium, iron and zinc concentrations in the white matter.

  16. Antisaccadic Eye Movements Are Correlated with Corpus Callosum White Matter Mean Diffusivity, Stroop Performance, and Symptom Burden in Mild Traumatic Brain Injury and Concussion

    PubMed Central

    Ting, Windsor Kwan-Chun; Schweizer, Tom A.; Topolovec-Vranic, Jane; Cusimano, Michael D.

    2016-01-01

    Antisaccades are thought to involve higher level inputs from neural centers involved in rapid eye movement inhibition and control. Previous work has demonstrated that performance on the antisaccade task can help in the assessment of injury in acute and/or chronic mild traumatic brain injury (mTBI). In this exploratory study, we performed cross-sectional and longitudinal comparisons of rapid eye movement, followed by correlations of antisaccade performance with assessments of symptom burden, diffusion tensor imaging, and a neuropsychological test of response inhibition. Significant deficits in antisaccade median latency, F(2, 31) = 3.65, p = 0.04 and prosaccade error mean duration, F(2, 31) = 3.63, p = 0.04 were found between patient groups and controls: the former was correlated with loss of white matter integrity in the splenium of the corpus callosum in acute mTBI, rho = 0.90, p = 0.0005. Furthermore, increased antisaccade median latency was also correlated with poor performance on an executive functioning task, r2 = 0.439, p = 0.03, and greater symptom burden, r2 = 0.480, p = 0.02 in the acute mTBI patients. Our preliminary research suggests that the antisaccade task could be useful as a neurological marker for mTBI and concussion, but more work is required. PMID:26834693

  17. Sex-related difference in human white matter volumes studied: Inspection of the corpus callosum and other white matter by VBM

    NASA Astrophysics Data System (ADS)

    Shiino, Akihiko; Chen, Yen-Wei; Tanigaki, Kenji; Yamada, Atsushi; Vigers, Piers; Watanabe, Toshiyuki; Tooyama, Ikuo; Akiguchi, Ichiro

    2017-01-01

    It has been contended that any observed difference of the corpus callosum (CC) size between men and women is not sex-related but brain-size-related. A recent report, however, showed that the midsagittal CC area was significantly larger in women in 37 brain-size-matched pairs of normal young adults. Since this constituted strong evidence of sexual dimorphism and was obtained from publicly available data in OASIS, we examined volume differences within the CC and in other white matter using voxel-based morphometry (VBM). We created a three-dimensional region of interest of the CC and measured its volume. The VBM statistics were analyzed by permutation test and threshold-free cluster enhancement (TFCE) with the significance levels at FWER < 0.05. The CC volume was significantly larger in women in the same 37 brain-size-matched pairs. We found that the CC genu was the subregion showing the most significant sex-related difference. We also found that white matter in the bilateral anterior frontal regions and the left lateral white matter near to Broca’s area were larger in women, whereas there were no significant larger regions in men. Since we used brain-size-matched subjects, our results gave strong volumetric evidence of localized sexual dimorphism of white matter.

  18. The effect of age, sex and clinical features on the volume of Corpus Callosum in pre-schoolers with Autism Spectrum Disorder: a case-control study.

    PubMed

    Giuliano, Alessia; Saviozzi, Irene; Brambilla, Paolo; Muratori, Filippo; Retico, Alessandra; Calderoni, Sara

    2017-01-23

    A growing body of literature has identified volume alterations of the corpus callosum (CC) in subjects with autism spectrum disorders (ASD). However, to date very few investigations have been conducted on pre-school-age ASD children. This study aims to compare the volume of CC and its sub-regions between pre-schoolers with ASD and controls (CON) and to examine their relationship to demographic and clinical variables (sex, age, non-verbal IQ -NVIQ-, expressive non-echolalic language, emotional and behavioural problems, and autism severity). The volume of CC of 40 pre-schoolers with ASD (20 males and 20 females; mean age: 49 ± 12 months; mean NVIQ: 73 ± 22) and 40 sex-, age-, and NVIQ-matched CON subjects (20 M and 20 F; mean age: 49 ± 14 months; mean NVIQ: 73 ± 23) were quantified applying the FreeSurfer automated parcellation software on Magnetic Resonance images. No significant volumetric differences in CC total volume and in its sub-regions between ASD and CON were found using total brain volume as a covariate. Analogously, absence of CC volumetric differences was evident when boys and girls with ASD were compared with their matched controls. The CC total volume of younger ASD male subjects was found significantly larger with respect to matched CON, which is consistent with the atypical growth trajectory widely reported in these young children. The CC total volume was negatively correlated with autism severity, whereas no association between CC volume and other clinical variables was detected. If replicated, the indirect relationship between CC volume and autism severity suggests the involvement of CC in core ASD symptoms.

  19. Recovery of axonal myelination sheath and axonal caliber in the mouse corpus callosum following damage induced by N,N-diethyldithiocarbamate.

    PubMed

    Utrera, Juana; Romero, Rafael; Verdaguer, Ester; Junyent, Fèlix; Auladell, Carme

    2011-12-01

    Disulfiram is an aldehyde dehydrogenase inhibitor used for the treatment of alcohol dependence and of cocaine addiction. It has been demonstrated that subchronic administration of disulfiram or N,N-diethyldithiocarbamate (DEDTC), the main derivative of disulfiram, to rats can produce central-peripheral distal axonopathy. However, few data regarding the axonal effects of these compounds in the central nervous system exist. Our previous studies have revealed DEDTC-induced axonal damage in the mouse brain during the course of postnatal development, together with alterations in axonal pathfinding and in the myelination process, with partial recovery during the post-treatment period. In order to gather new data about how this axonal damage and recovery occurs in the central nervous system, we performed an ultrastructural analysis of the axons located in the corpus callosum from mice treated with DEDTC during postnatal development. The axonal caliber throughout the axonal area, the maximum axonal diameter, the maximum fiber diameter, and the axonal circularity, at different postnatal stages [from postnatal day (P)9 to P30], were analyzed. In addition, parameters related to the myelinization process (number of myelinated axons, sheath thickness, and the ratio of myelinated axons to total axons) were evaluated. A reduction in the average value of axonal caliber during treatment and a delay in the axonal myelination process were detected. Whereas early recovery of individual axons occurred after treatment (P22), complete recovery of myelinated axons occurred at late postnatal stages (P42). Therefore, chronic treatment with dithiocarbamates requires periods of rest to encourage the recovery of myelinated axons.

  20. Impairment in explicit visuomotor sequence learning is related to loss of microstructural integrity of the corpus callosum in multiple sclerosis patients with minimal disability.

    PubMed

    Bonzano, L; Tacchino, A; Roccatagliata, L; Sormani, M P; Mancardi, G L; Bove, M

    2011-07-15

    Sequence learning can be investigated by serial reaction-time (SRT) paradigms. Explicit learning occurs when subjects have to recognize a test sequence and has been shown to activate the frontoparietal network in both contralateral and ipsilateral hemispheres. Thus, the left and right superior longitudinal fasciculi (SLF), connecting the intra-hemispheric frontoparietal circuits, could have a role in explicit unimanual visuomotor learning. Also, as both hemispheres are involved, we could hypothesize that the corpus callosum (CC) has a role in this process. Pathological damage in both SLF and CC has been detected in patients with Multiple Sclerosis (PwMS), and microstructural alterations can be quantified by Diffusion Tensor Imaging (DTI). In light of these findings, we inquired whether PwMS with minimal disability showed impairments in explicit visuomotor sequence learning and whether this could be due to loss of white matter integrity in these intra- and inter-hemispheric white matter pathways. Thus, we combined DTI analysis with a modified version of SRT task based on finger opposition movements in a group of PwMS with minimal disability. We found that the performance in explicit sequence learning was significantly reduced in these patients with respect to healthy subjects; the amount of sequence-specific learning was found to be more strongly correlated with fractional anisotropy (FA) in the CC (r=0.93) than in the left (r=0.28) and right SLF (r=0.27) (p for interaction=0.005 and 0.04 respectively). This finding suggests that an inter-hemispheric information exchange between the homologous areas is required to successfully accomplish the task and indirectly supports the role of the right (ipsilateral) hemisphere in explicit visuomotor learning. On the other hand, we found no significant correlation of the FA in the CC and in the SLFs with nonspecific learning (assessed when stimuli are randomly presented), supporting the hypothesis that inter

  1. The Microstructural Status of the Corpus Callosum Is Associated with the Degree of Motor Function and Neurological Deficit in Stroke Patients

    PubMed Central

    Liang, Fanrong; Huang, Wenhua

    2015-01-01

    Human neuroimaging studies and animal models have suggested that white matter damage from ischemic stroke leads to the functional and structural reorganization of perilesional and remote brain regions. However, the quantitative relationship between the transcallosal tract integrity and clinical motor performance score after stroke remains unexplored. The current study employed a tract-based spatial statistics (TBSS) analysis on diffusion tensor imaging (DTI) to investigate the relationship between white matter diffusivity changes and the clinical scores in stroke patients. Probabilistic fiber tracking was also used to identify structural connectivity patterns in the patients. Thirteen ischemic stroke patients and fifteen healthy control subjects participated in this study. TBSS analyses showed that the corpus callosum (CC) and bilateral corticospinal tracts (CST) in the stroke patients exhibited significantly decreased fractional anisotropy and increased axial and radial diffusivity compared with those of the controls. Correlation analyses revealed that the motor and neurological deficit scores in the stroke patients were associated with the value of diffusivity indices in the CC. Compared with the healthy control group, probabilistic fiber tracking analyses revealed that significant changes in the inter-hemispheric fiber connections between the left and right motor cortex in the stroke patients were primarily located in the genu and body of the CC, left anterior thalamic radiation and inferior fronto-occipital fasciculus, bilateral CST, anterior/superior corona radiate, cingulum and superior longitudinal fasciculus, strongly suggesting that ischemic induces inter-hemispheric network disturbances and disrupts the white matter fibers connecting motor regions. In conclusion, the results of the present study show that DTI-derived measures in the CC can be used to predict the severity of motor skill and neurological deficit in stroke patients. Changes in structural

  2. IMPACT OF EARLY AND LATE VISUAL DEPRIVATION ON THE STRUCTURE OF THE CORPUS CALLOSUM: A STUDY COMBINING THICKNESS PROFILE WITH SURFACE TENSOR-BASED MORPHOMETRY

    PubMed Central

    Shi, Jie; Collignon, Olivier; Xu, Liang; Wang, Gang; Kang, Yue; Leporé, Franco; Lao, Yi; Joshi, Anand A.

    2015-01-01

    Blindness represents a unique model to study how visual experience may shape the development of brain organization. Exploring how the structure of the corpus callosum (CC) reorganizes ensuing visual deprivation is of particular interest due to its important functional implication in vision (e.g. via the splenium of the CC). Moreover, comparing early versus late visually deprived individuals has the potential to unravel the existence of a sensitive period for reshaping the CC structure. Here, we develop a novel framework to capture a complete set of shape differences in the CC between congenitally blind (CB), late blind (LB) and sighted control (SC) groups. The CCs were manually segmented from T1-weighted brain MRI and modeled by 3D tetrahedral meshes. We statistically compared the combination of local area and thickness at each point between subject groups. Differences in area are found using surface tensor-based morphometry; thickness is estimated by tracing the streamlines in the volumetric harmonic field. Group differences were assessed on this combined measure using Hotelling’s T2 test. Interestingly, we observed that the total callosal volume did not differ between the groups. However, our fine-grained analysis reveals significant differences mostly localized around the splenium areas between both blind groups and the sighted group (general effects of blindness) and, importantly, specific dissimilarities between the LB and CB groups, illustrating the existence of a sensitive period for reorganization. The new multivariate statistics also gave better effect sizes for detecting morphometric differences, relative to other statistics. They may boost statistical power for CC morphometric analyses. PMID:25649876

  3. Agenesis of the Corpus Callosum

    MedlinePlus

    ... Chiari malformation, Dandy-Walker syndrome, schizencephaly (clefts or deep divisions in brain tissue), and holoprosencephaly (failure of ... Chiari malformation, Dandy-Walker syndrome, schizencephaly (clefts or deep divisions in brain tissue), and holoprosencephaly (failure of ...

  4. Endoscopic posterior interhemispheric complete corpus callosotomy.

    PubMed

    Sood, Sandeep; Asano, Eishi; Altinok, Deniz; Luat, Aimee

    2016-12-01

    Traditionally corpus callosotomy is done through a craniotomy centered at the coronal suture, with the aid of a microscope. This involves dissecting through the interhemispheric fissure below the falx to reach the corpus callosum. The authors describe a posterior interhemispheric approach to complete corpus callosotomy with an endoscope, which bypasses the need to perform interhemispheric dissection because the falx is generally close to the corpus callosum in this region.

  5. Absent Apologies

    ERIC Educational Resources Information Center

    Drew, Paul; Hepburn, Alexa

    2016-01-01

    Absent apologies--apologies that were expected but are not forthcoming--are quite frequently identified and commented on, for instance in the media. In this article we discuss two kinds of evidence that apologies can be "noticeably" absent for participants in ordinary interactions. The first kind is the delays that can occur in the…

  6. Impaired visual short-term memory capacity is distinctively associated with structural connectivity of the posterior thalamic radiation and the splenium of the corpus callosum in preterm-born adults.

    PubMed

    Menegaux, Aurore; Meng, Chun; Neitzel, Julia; Bäuml, Josef G; Müller, Hermann J; Bartmann, Peter; Wolke, Dieter; Wohlschläger, Afra M; Finke, Kathrin; Sorg, Christian

    2017-02-07

    Preterm birth is associated with an increased risk for lasting changes in both the cortico-thalamic system and attention; however, the link between cortico-thalamic and attention changes is as yet little understood. In preterm newborns, cortico-cortical and cortico-thalamic structural connectivity are distinctively altered, with increased local clustering for cortico-cortical and decreased integrity for cortico-thalamic connectivity. In preterm-born adults, among the various attention functions, visual short-term memory (vSTM) capacity is selectively impaired. We hypothesized distinct associations between vSTM capacity and the structural integrity of cortico-thalamic and cortico-cortical connections, respectively, in preterm-born adults. A whole-report paradigm of briefly presented letter arrays based on the computationally formalized Theory of Visual Attention (TVA) was used to quantify parameter vSTM capacity in 26 preterm- and 21 full-term-born adults. Fractional anisotropy (FA) of posterior thalamic radiations and the splenium of the corpus callosum obtained by diffusion tensor imaging were analyzed by tract-based spatial statistics and used as proxies for cortico-thalamic and cortico-cortical structural connectivity. The relationship between vSTM capacity and cortico-thalamic and cortico-cortical connectivity, respectively, was significantly modified by prematurity. In full-term-born adults, the higher FA in the right posterior thalamic radiation the higher vSTM capacity; in preterm-born adults this FA-vSTM-relationship was inversed. In the splenium, higher FA was correlated with higher vSTM capacity in preterm-born adults, whereas no significant relationship was evident in full-term-born adults. These results indicate distinct associations between cortico-thalamic and cortico-cortical integrity and vSTM capacity in preterm-and full-term-born adults. Data suggest compensatory cortico-cortical fiber re-organization for attention deficits after preterm delivery.

  7. Corpus Callosum Morphology in Children Who Stutter

    ERIC Educational Resources Information Center

    Choo, Ai Leen; Chang, Soo-Eun; Zengin-Bolatkale, Hatun; Ambrose, Nicoline G.; Loucks, Torrey M.

    2012-01-01

    Multiple studies have reported both functional and neuroanatomical differences between adults who stutter and their normally fluent peers. However, the reasons for these differences remain unclear although some developmental data suggest that structural brain differences may be present in school-age children who stutter. In the present study, the…

  8. Prosody Meets Syntax: The Role of the Corpus Callosum

    ERIC Educational Resources Information Center

    Sammler, Daniela; Kotz, Sonja A.; Eckstein, Korinna; Ott, Derek V. M.; Friederici, Angela D.

    2010-01-01

    Contemporary neural models of auditory language comprehension proposed that the two hemispheres are differently specialized in the processing of segmental and suprasegmental features of language. While segmental processing of syntactic and lexical semantic information is predominantly assigned to the left hemisphere, the right hemisphere is…

  9. Communication as Corpus Callosum: A Reorganization of Knowledge.

    ERIC Educational Resources Information Center

    Cooper, Thomas

    1993-01-01

    Argues that communication, as an academic discipline and as an ongoing process, can be seen as a bridge between the two hemispheres within the liberal arts brain. Discusses unique changes within communication in the twentieth century. Maintains that communication theory may serve as one new method of connecting the liberal arts. (SR)

  10. Minimally Invasive Robotic Laser Corpus Callosotomy: A Proof of Concept

    PubMed Central

    Essayed, Walid I; Deb, Sayantan; Hoffman, Caitlin; Schwartz, Theodore H

    2017-01-01

    Introduction We describe the feasibility of using minimally invasive robotic laser interstitial thermotherapy (LITT) for achieving an anterior two-thirds as well as a complete corpus callosotomy. Methods Ten probe trajectories were plotted on normal magentic resonance imaging (MRI) scans using the Brainlab Stereotactic Planning Software (Brainlab, Munich, Germany). The NeuroBlate® System (Monteris Medical, MN, USA) was used to conform the thermal burn to the corpus callosum along the trajectory of the probe. The distance of the ideal entry site from either the coronal suture and the torcula or nasion and the midline was calculated. The distance of the probe tip from the dorsal and ventral limits of the callosotomy in the sagittal plane were also calculated. Results Anterior two-thirds callosotomy was possible in all patients using a posterior parieto-occipital paramedian trajectory through the non-dominant lobe. The average entry point was 3.64 cm from the midline, 10.6 cm behind the coronal suture, and 9.2 cm above the torcula. The probe tip was an average of 1.4 cm from the anterior commissure. For a total callosotomy, an additional contralaterally placed frontal probe was used to target the posterior one-third of the corpus callosum. The average entry site was 3.3 cm from the midline and 9.1 cm above the nasion. The average distance of the probe tip from the base of the splenium was 0.94 cm. Conclusion The directional thermoablation capability of the NeuroBlate® system allows for targeted lesioning of the corpus callosum, to achieve a two-thirds or complete corpus callosotomy. A laser distance of < 2 cm is sufficient to reach the entire corpus callosum through one trajectory for an anterior two-thirds callosotomy and two trajectories for a complete callosotomy. PMID:28348940

  11. Absent or occult pulmonary artery.

    PubMed Central

    Presbitero, P; Bull, C; Haworth, S G; de Leval, M R

    1984-01-01

    Of 12 patients with angiographically absent pulmonary artery, 11 were investigated surgically. The previously occult pulmonary artery was found in 10 patients, in five of whom a vestige of an intrapericardial artery was present and in five the artery was patent only at the hilus, a gap existing between the main pulmonary artery and the hilar vessel, and no artery was found in one. All patients with an intrapericardial artery had right ventricular outflow tract obstruction and a ductus descending vertically from underneath the aortic arch. In those without an intrapericardial vessel the occult artery was on the side opposite the aortic arch, and there was evidence of a ductus coming from the innominate artery on the side of the interruption. The occult pulmonary artery, where identified at operation, was usually joined initially to the systemic circulation. Ultimately, continuity between the hilar and main pulmonary artery may be established surgically. Where no intrapericardial vessel exists, however, a conduit may be required to bridge the gap. It seems advisable to search for the occult artery as early in life as is feasible in the hope that providing a blood supply will ensure development of the vessel and normal lung growth. Images PMID:6743435

  12. Corpus Christi, Texas

    NASA Technical Reports Server (NTRS)

    1992-01-01

    This near vertical view of the south Texas coast shows the city of Corpus Christi (28.0N, 97.0W) and Corpus Christi Bay. Mustang Island and the Gulf of Mexico are seen in the Southeast corner of the view. The Nueces River flows into the bay from the west. The light toned squiggly lines in Corpus Christi Bay are mud trails caused by shrimp boats dragging their nets along the shallow bottom of the bay.

  13. Congenitally absent lumbar pedicle: a reappraisal

    SciTech Connect

    Wortzman, G.; Steinhardt, M.I.

    1984-09-01

    Three patients who had a diagnosis of congenitally absent lumbar pedicle underwent CT examination. Findings showed that each patient had an aberrant hypoplastic pedicle plus a retroisthmic defect in their ipsilateral lamina rather than an absent pedicle. Axial CT was the diagnostic modality of choice; reformated images were of little value. The differential diagnosis to be considered from the findings of plain film radiography includes pediculate thinning, neoplastic disease, neurofibroma, mesodermal dysplasia associated with neurofibromatosis, and vascular anomalies.

  14. Magnetic resonance imaging and histological studies of corpus callosal and hippocampal abnormalities linked to doublecortin deficiency.

    PubMed

    Kappeler, Caroline; Dhenain, Marc; Phan Dinh Tuy, Françoise; Saillour, Yoann; Marty, Serge; Fallet-Bianco, Catherine; Souville, Isabelle; Souil, Evelyne; Pinard, Jean-Marc; Meyer, Gundela; Encha-Razavi, Ferechté; Volk, Andreas; Beldjord, Cherif; Chelly, Jamel; Francis, Fiona

    2007-01-10

    Mutated doublecortin (DCX) gives rise to severe abnormalities in human cortical development. Adult Dcx knockout mice show no major neocortical defects but do have a disorganized hippocampus. We report here the developmental basis of these hippocampal abnormalities. A heterotopic band of neurons was identified starting at E17.5 in the CA3 region and progressing throughout the CA1 region by E18.5. At neonatal stages, the CA1 heterotopic band was reduced, but the CA3 band remained unchanged, continuing into adulthood. Thus, in mouse, migration of CA3 neurons is arrested during development, whereas CA1 cell migration is retarded. On the Sv129Pas background, magnetic resonance imaging (MRI) also suggested abnormal dorsal hippocampal morphology, displaced laterally and sometimes rostrally and associated with medial brain structure abnormalities. MRI and cryosectioning showed agenesis of the corpus callosum in Dcx knockout mice on this background and an intermediate, partial agenesis in heterozygote mice. Wild-type littermates showed no callosal abnormalities. Hippocampal and corpus callosal abnormalities were also characterized in DCX-mutated human patients. Severe hippocampal hypoplasia was identified along with variable corpus callosal defects ranging from total agenesis to an abnormally thick or thin callosum. Our data in the mouse, identifying roles for Dcx in hippocampal and corpus callosal development, might suggest intrinsic roles for human DCX in the development of these structures.

  15. DEVELOPMENTAL HYPOTHYROIDISM INDUCES A NEURONAL HETEROTOPIA IN THE CORPUS CALLOSUM OF THE RAT.

    EPA Science Inventory

    It is well established that severe hypothyroidism leads to profound alterations in brain development and mental retardation. In this study we examined the effect of subtle decreases in maternal thyroid hormones (TH) on brain development in the rat. To induce TH insufficiency pr...

  16. Reduced Gyral Window and Corpus Callosum Size in Autism: Possible Macroscopic Correlates of a Minicolumnopathy

    ERIC Educational Resources Information Center

    Casanova, Manuel F.; El-Baz, Ayman; Mott, Meghan; Mannheim, Glenn; Hassan, Hossam; Fahmi, Rachid; Giedd, Jay; Rumsey, Judith M.; Switala, Andrew E.; Farag, Aly

    2009-01-01

    Minicolumnar changes that generalize throughout a significant portion of the cortex have macroscopic structural correlates that may be visualized with modern structural neuroimaging techniques. In magnetic resonance images (MRIs) of fourteen autistic patients and 28 controls, the present study found macroscopic morphological correlates to recent…

  17. Diffusion tensor imaging, white matter lesions, the corpus callosum, and gait in the elderly

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Gait impairment is common in the elderly, especially affected by stroke and white matter hyper intensities found in conventional brain magnetic resonance imaging (MRI). Diffusion tensor imaging (DTI) is more sensitive to white matter damage than conventional MRI. The relationship between DTI measure...

  18. Microstructural Integrity of the Corpus Callosum Linked with Neuropsychological Performance in Adolescents

    ERIC Educational Resources Information Center

    Fryer, Susanna L.; Frank, Lawrence R.; Spadoni, Andrea D.; Theilmann, Rebecca J.; Nagel, Bonnie J.; Schweinsburg, Alecia D.; Tapert, Susan F.

    2008-01-01

    Background: Diffusion tensor imaging (DTI) has revealed microstructural aspects of adolescent brain development, the cognitive correlates of which remain relatively uncharacterized. Methods: DTI was used to assess white matter microstructure in 18 typically developing adolescents (ages 16-18). Fractional anisotropy (FA) and mean diffusion (MD)…

  19. The Association of Macro- and Microstructure of the Corpus Callosum and Language Lateralisation

    ERIC Educational Resources Information Center

    Westerhausen, Rene; Kreuder, Frank; Sequeira, Sarah Dos Santos; Walter, Christof; Woerner, Wolfgang; Wittling, Ralf Arne; Schweiger, Elisabeth; Wittling, Werner

    2006-01-01

    The present study aimed to examine how differences in functional lateralisation of language are related to interindividual variations in interhemispheric connectivity. Utilising an fMRI silent word-generation paradigm, 89 left- and right-handed subjects were subdivided into four lateralisation subgroups. Applying morphological and diffusion-tensor…

  20. "Thoughts across My Corpus Callosum": What Lewis Thomas's Essays Can Teach Students about Writing Well.

    ERIC Educational Resources Information Center

    White, Fred D.

    As Lewis Thomas has maintained, much of today's public anxiety about science is the apprehension that the whole is being overlooked by an endless, obsessive preoccupation with the parts, and this is a suitable analogy for composition teaching. Students and teachers alike tend to fret endlessly over minute details of writing, like grammar,…

  1. Developing Software for Corpus Research

    ERIC Educational Resources Information Center

    Mason, Oliver

    2008-01-01

    Despite the central role of the computer in corpus research, programming is generally not seen as a core skill within corpus linguistics. As a consequence, limitations in software for text and corpus analysis slow down the progress of research while analysts often have to rely on third party software or even manual data analysis if no suitable…

  2. Importance of absent ductus arteriosus in tetralogy of Fallot with absent pulmonary valve syndrome.

    PubMed

    Qureshi, Muhammad Yasir; Burkhart, Harold M; Julsrud, Paul; Cetta, Frank

    2014-12-01

    Tetralogy of Fallot without pulmonary valve syndrome is almost always associated with an absent ductus arteriosus. Patients with right aortic arch and retroesophageal left subclavian artery have a vascular ring if the left ductus arteriosus or its remnant and the Kommerell diverticulum are present. We report the cases of 2 infants in whom the role of an absent ductus arteriosus or its remnant is noteworthy. Both patients had a combination of tetralogy of Fallot with absent pulmonary valve syndrome and right aortic arch with retroesophageal left subclavian artery without a vascular ring. The absence of the ductus arteriosus has a role in the pathogenesis of tetralogy of Fallot with absent pulmonary valve syndrome. The absence of a ductus arteriosus in the right aortic arch with retroesophageal left subclavian artery precludes a vascular ring.

  3. Habeas Corpus and "Enemy Combatants"

    ERIC Educational Resources Information Center

    Pereira, Carolyn; Chavkin, Nisan

    2008-01-01

    The writ of habeas corpus has been a critical tool for balancing the rights of individuals with the government's responsibility to protect the nation's welfare. In this article, the authors discuss the writ of habeas corpus and how it affects the federal government and hundreds of prisoners who are held as enemy combatants. Elementary, middle, and…

  4. [Corpus Hermeticum in history].

    PubMed

    Bugaj, R

    2001-01-01

    The originator and founder of hermetism was the mythical Hermes Trismegistos, a deity of the syncretic Hellenistic religion that came into being through the identification of the Greek god Hermes with the Egyptian god Thot. In later Hellenistsic times various hermetic writers considered Hermes Trismegistos to have been a historical personage, a king, prophet and philosopher (physician), as well as author of many widely disseminated writings that made up the so-called Corpus Hermeticum (eighteen separate treatises from the 2nd-4th centuries AD) and the so-called Emerald Table (Tabula Smaragdina). The Corpus Hermeticum is a collection of treatises of a philosophical, religious, theological as well as theosophical nature. The collection played an important role in the development of the philosophy of alchemy and hermetism, and formed the basis for an alchemist philosophy of nature. There are currently two views among scholars on the origins of hermetism. According to one, hermetism derived directly from Egypt, while according to the other it orginated in Greece. In the years 1945-46 a number of hermetic texts forming part of the now famous gnostic "library" were discovered in Nag-Hammadi (Chenosboskion) in Upper Egypt. The Coptic texts from Nag-Hammadi date from the middle of the 4th century AD, and according to experts are translations from the Greek. Some authors (R. Reitzenstein and T. Zieliński) have suggested that along with the appearance in Egypt of the Hermetic Books, attributed to Hermes Trismegistos, there also appeared a new god in Egypt, Poimandres, and a new religion was established, hermetism, which competed for influence with Christianity. The present article discusses the main of the hermetic treatises, including Poimandres, which contains an account of the creation of the world. The article also discusses the reasons for the decline of hermetism as a religion and stresses that in spite of this decline the doctrine managed to survive in the form of

  5. Universum Inference and Corpus Homogeneity

    NASA Astrophysics Data System (ADS)

    Vogel, Carl; Lynch, Gerard; Janssen, Jerom

    Universum Inference is re-interpreted for assessment of corpus homogeneity in computational stylometry. Recent stylometric research quantifies strength of characterization within dramatic works by assessing the homogeneity of corpora associated with dramatic personas. A methodological advance is suggested to mitigate the potential for the assessment of homogeneity to be achieved by chance. Baseline comparison analysis is constructed for contributions to debates by nonfictional participants: the corpus analyzed consists of transcripts of US Presidential and Vice-Presidential debates from the 2000 election cycle. The corpus is also analyzed in translation to Italian, Spanish and Portuguese. Adding randomized categories makes assessments of homogeneity more conservative.

  6. Absent in Melanoma 2 proteins in SLE.

    PubMed

    Choubey, Divaker; Panchanathan, Ravichandran

    2017-03-01

    Type I interferons (IFN-α/β)-inducible PYRIN and HIN domain-containing protein family includes Absent in Melanoma 2 (murine Aim2 and human AIM2), murine p202, and human PYRIN-only protein 3 (POP3). The generation of Aim2-deficient mice indicated that the Aim2 protein is essential for inflammasome activation, resulting in the secretion of interleukin-1β (IL-1β) and IL-18 and cell death by pyroptosis. Further, Aim2-deficiency also increased constitutive expression of the IFN-β and expression of the p202 protein. Notably, an increased expression of p202 protein in female mice associated with the development of systemic lupus erythematosus (SLE). SLE in patients is characterized by a constitutive increase in serum levels of IFN-α and an increase in the expression IFN-stimulated genes. Recent studies indicate that p202 and POP3 proteins inhibit activation of the Aim2/AIM2 inflammasome and promote IFN-β expression. Therefore, we discuss the role of Aim2/AIM2 proteins in the suppression of type I IFNs production and lupus susceptibility.

  7. Genetic Influences Are Virtually Absent for Trust

    PubMed Central

    Van Lange, Paul A. M.; Vinkhuyzen, Anna A. E.; Posthuma, Danielle

    2014-01-01

    Over the past decades, numerous twin studies have revealed moderate to high heritability estimates for individual differences in a wide range of human traits, including cognitive ability, psychiatric disorders, and personality traits. Even factors that are generally believed to be environmental in nature have been shown to be under genetic control, albeit modest. Is such heritability also present in social traits that are conceptualized as causes and consequences of social interactions or in other ways strongly shaped by behavior of other people? Here we examine a population-based sample of 1,012 twins and relatives. We show that the genetic influence on generalized trust in other people (trust-in-others: h2 = 5%, ns), and beliefs regarding other people’s trust in the self (trust-in-self: h2 = 13%, ns), is virtually absent. As test-retest reliability for both scales were found to be moderate or high (r = .76 and r = .53, respectively) in an independent sample, we conclude that all variance in trust is likely to be accounted for by non-shared environmental influences. We show that, relative to cognitive abilities, psychiatric disorders, and classic personality variables, genetic influences are smaller for trust, and propose that experiences with or observations of the behavior of other people shape trust more strongly than other traits. PMID:24709897

  8. Absence of anatomic corpus callosal abnormalities in childhood-onset schizophrenia patients and healthy siblings.

    PubMed

    Johnson, Sarah L M; Greenstein, Deanna; Clasen, Liv; Miller, Rachel; Lalonde, Francois; Rapoport, Judith; Gogtay, Nitin

    2013-01-30

    The corpus callosum (CC) has been implicated in the pathogenesis of schizophrenia, and CC deficits have been reported in adults with schizophrenia. We explored the developmental trajectory of the corpus callosum in childhood-onset schizophrenia (COS) patients, their healthy siblings (SIB) and healthy volunteers. We obtained 235 anatomic brain magnetic resonance imaging (MRI) scans from 98 COS patients, 153 scans from 71 of their healthy siblings, and 253 scans from 100 age- and gender-matched healthy volunteers, across ages 9-30 years. The volumes of five sub-regions of the CC were calculated using FreeSurfer, and summed to give the total volume. Longitudinal data were examined using mixed model regression analysis. There were no significant differences for the total or sub-regional CC volumes between the three groups. There were also no significant differences between the groups for developmental trajectory (slope) of the CC. This is the largest longitudinal study of CC development in schizophrenia and the first COS study of the CC to include healthy siblings. Overall, CC volume and growth trajectory did not differ between COS patients, healthy siblings, or healthy volunteers. These results suggest that CC development, at least at a macroscopic level, may not be a salient feature of schizophrenia.

  9. Corpus Refactoring: a Feasibility Study

    PubMed Central

    Johnson, Helen L; Baumgartner, William A; Krallinger, Martin; Cohen, K Bretonnel; Hunter, Lawrence

    2007-01-01

    Background Most biomedical corpora have not been used outside of the lab that created them, despite the fact that the availability of the gold-standard evaluation data that they provide is one of the rate-limiting factors for the progress of biomedical text mining. Data suggest that one major factor affecting the use of a corpus outside of its home laboratory is the format in which it is distributed. This paper tests the hypothesis that corpus refactoring – changing the format of a corpus without altering its semantics – is a feasible goal, namely that it can be accomplished with a semi-automatable process and in a time-effcient way. We used simple text processing methods and limited human validation to convert the Protein Design Group corpus into two new formats: WordFreak and embedded XML. We tracked the total time expended and the success rates of the automated steps. Results The refactored corpus is available for download at the BioNLP SourceForge website http://bionlp.sourceforge.net. The total time expended was just over three person-weeks, consisting of about 102 hours of programming time (much of which is one-time development cost) and 20 hours of manual validation of automatic outputs. Additionally, the steps required to refactor any corpus are presented. Conclusion We conclude that refactoring of publicly available corpora is a technically and economically feasible method for increasing the usage of data already available for evaluating biomedical language processing systems. PMID:17854502

  10. Communication about absent entities in great apes and human infants.

    PubMed

    Bohn, Manuel; Call, Josep; Tomasello, Michael

    2015-12-01

    There is currently debate about the extent to which non-linguistic beings such as human infants and great apes are capable of absent reference. In a series of experiments we investigated the flexibility and specificity of great apes' (N=36) and 12 month-old infants' (N=40) requests for absent entities. Subjects had the choice between requesting visible objects directly and using the former location of a depleted option to request more of these now-absent entities. Importantly, we systematically varied the quality of the present and absent options. We found that great apes as well as human infants flexibly adjusted their requests for absent entities to these contextual variations and only requested absent entities when the visible option was of lower quality than the absent option. These results suggest that the most basic cognitive capacities for absent reference do not depend on language and are shared by humans and their closest living relatives.

  11. Absent Aortic Valve in DiGeorge Syndrome.

    PubMed

    Bertsch, Elizabeth C; Minturn, Lucy; Gotteiner, Nina L; Ernst, Linda M

    2016-01-01

    A 20-week-old fetus with the 22q11.2 deletion characteristic of DiGeorge syndrome is described with vertebral segmentation abnormalities and complex cardiovascular anomalies including an absent aortic valve. This is only the second known case of absent aortic valve in association with DiGeorge syndrome. We discuss the association of absent aortic valve with other conotruncal defects and the utility of fetal echocardiography in the diagnosis of DiGeorge syndrome.

  12. Corpus-based Customization for an Ontology

    SciTech Connect

    2010-09-14

    CCAT scans a corpus of text for terms, and computes lexical similarity between corpus terms and taxonomy terms. Based on a set of metrics and a learning algorithm, the system inserts corpus terms into the taxonomy. Conversely, terms from the taxonomy are disambiguated based on the text in the corpus. Unused terms are discarded, and infrequently used senses of terms are collapsed to make the taxonomy more manageable.

  13. Developing an International Corpus of Creative English

    ERIC Educational Resources Information Center

    Hassall, Peter John

    2006-01-01

    This paper proposes an International Corpus of Creative English (ICCE) as a worldwide corpus particularly suitable for implementation in countries which have tertiary institutions with well-defined populations of students possessing similar cultural and/or linguistic backgrounds. The ICCE is contextualized as a world Englishes corpus with…

  14. Channels of the corpus callosum. Evidence from simple reaction times to lateralized flashes in the normal and the split brain.

    PubMed

    Iacoboni, M; Zaidel, E

    1995-06-01

    We studied 75 normal subjects and three commissurotomized patients using unimanual simple reaction times to lateralized flashes as a behavioural estimate of interhemispheric transmission time. Three different versions of the paradigm were performed: (i) the basic task; (ii) a motor task, with an increased complexity of the motor response; and (iii) a visual task, with an increased complexity of the visual stimulus presentation. We tested two hypotheses. First, that the new versions of the simple reaction time task result in shifts in hemispheric specialization for processing motor output (indicated by a main effect of response hand) or visual input (indicated by a main effect of visual field) alone, without affecting callosal transmission. In that case normals and split brain patients would show no significant task by response hand by visual field interaction and no significant task by crossed-uncrossed difference interaction. Secondly, that the new versions of the task affect callosal transfer. In that case, normals, but not split brain patients, would show a significant task by response hand by visual field interaction and a significant task by crossed-uncrossed difference interaction. Results are consistent with the latter hypothesis, showing that the motor task significantly changed the response hand by visual field interaction and the crossed-uncrossed difference, but only in normal subjects, perhaps producing a switch in the callosal channel subserving the interhemispheric transfer.

  15. [Shearing injuries of parasagittal white matter, corpus callosum and basal ganglia: possible radiological evidences of hemiplegia in diffuse axonal injury].

    PubMed

    Masuzawa, H; Kubo, T; Kanazawa, I; Kamitani, H; Nakamura, N

    1997-08-01

    The relationship between spastic hemiplegia in diffuse axonal injury (DAI) and neuroradiological findings was studied in 100 cases. These cases were prospectively collected from the files of Automobile Insurance Rating Organization in Japan between 1993 from to 1996. Requirements for entry to this study were as follows: presence of initial unconsciousness after head injury without any lucid interval. Existence of CT scan or MRI film obtained within 12 hours of injury showing no significant mass effects, as well as follow-up CT scan or MRI film obtained more than 3 months after the injury. Psychosocial outcome was described both by the medical professional and the caregiver. The hemiplegia was rated severe, mild, or none. The outcome and diffuse ventriculomegaly were classified as reported by the authors previously. Spastic hemiplegia or quadriplegia was documented in the chronic stage in 63 cases, including 53 severe cases with difficulty in walking and 10 mild cases with only pyramidal signs detected. Chi-square analysis showed significant correlation between hemiplegia and the DAI outcome level or ventriculomegaly rating. Focal brain contusion was noticed in 33 cases, but did not correlate with the hemiplegia at all. Radiological findings included 25 cases of parasagittal white matter injury (gliding contusion), 20 cases of callosal injury, 19 cases of basal ganglionic region injury, 5 cases of brain-stem injury, and 3 cases of cerebellar injury. Chi-square analyses of hemiplegia and contralateral presence of these injuries were significant in the former three types of injury. Presence of at least one of these 3 lesions was defined as GCB injury. There were altogether 46 GCB injury cases which were significantly correlated with contralateral hemiplegia by chi-square analysis and by Spearman rank analysis. Partial correlation analysis with hemiplegia as the target variable indicated highly significant correlation only with GCB injury and outcome level. In conclusion, spastic hemiplegia in DAI is a manifestation of primary shear injury. Neuroradiological findings of GCB injury were statistically able to be significantly correlated with the presence of hemiplegia, and suggested pyramidal tract injury either at the corona radiata or the internal capsule level.

  16. Idiom Comprehension Deficits in Relation to Corpus Callosum Agenesis and Hypoplasia in Children with Spina Bifida Meningomyelocele

    ERIC Educational Resources Information Center

    Huber-Okrainec, J.; Blaser, S.E.; Dennis, M.

    2005-01-01

    Idioms are phrases with figurative meanings that are not directly derived from the literal meanings of the words in the phrase. Idiom comprehension varies with: literality, whether the idiom is literally plausible; compositionality, whether individual words contribute to a figurative meaning; and contextual bias. We studied idiom comprehension in…

  17. Amygdala, Hippocampal and Corpus Callosum Size Following Severe Early Institutional Deprivation: The English and Romanian Adoptees Study Pilot

    ERIC Educational Resources Information Center

    Mehta, Mitul A.; Golembo, Nicole I.; Nosarti, Chiara; Colvert, Emma; Mota, Ashley; Williams, Steven C. R.; Rutter, Michael; Sonuga-Barke, Edmund J. S.

    2009-01-01

    The adoption into the UK of children who have been reared in severely deprived conditions provides an opportunity to study possible association between very early negative experiences and subsequent brain development. This cross-sectional study was a pilot for a planned larger study quantifying the effects of early deprivation on later brain…

  18. MODEST THYROID HORMONE INSUFFICIENCY DURING DEVELOPMENT INDUCES A CELLULAR MALFORMATION IN THE CORPUS CALLOSUM: A MODEL OF CORTICAL DYSPLASIA.

    EPA Science Inventory

    There is a growing body of evidence that subtle decreases in maternal thyroid hormone during gestation can impact fetal brain development. The present study examined the impact of graded levels of thyroid hormone insufficiency on brain development in rodents. Maternal thyroid ho...

  19. Unique Cellular Lineage Composition of the First Gland of the Mouse Gastric Corpus.

    PubMed

    O'Neil, Andrew; Petersen, Christine P; Choi, Eunyoung; Engevik, Amy C; Goldenring, James R

    2017-01-01

    The glandular stomach has two major zones: the acid secreting corpus and the gastrin cell-containing antrum. Nevertheless, a single gland lies at the transition between the forestomach and corpus in the mouse stomach. We have sought to define the lineages that make up this gland unit at the squamocolumnar junction. The first gland in mice showed a notable absence of characteristic corpus lineages, including parietal cells and chief cells. In contrast, the gland showed strong staining of Griffonia simplicifolia-II (GSII)-lectin-positive mucous cells at the bases of glands, which were also positive for CD44 variant 9 and Clusterin. Prominent numbers of doublecortin-like kinase 1 (DCLK1) positive tuft cells were present in the first gland. The first gland contained Lgr5-expressing putative progenitor cells, and a large proportion of the cells were positive for Sox2. The cells of the first gland stained strongly for MUC4 and EpCAM, but both were absent in the normal corpus mucosa. The present studies indicate that the first gland in the corpus represents a unique anatomic entity. The presence of a concentration of progenitor cells and sensory tuft cells in this gland suggests that it may represent a source of reserve reparative cells for adapting to severe mucosal damage.

  20. 77 FR 2448 - Special Local Regulation; HITS Triathlon; Corpus Christi Bayfront, Corpus Christi, TX

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-18

    ... SECURITY Coast Guard 33 CFR Part 100 RIN 1625-AA08 Special Local Regulation; HITS Triathlon; Corpus Christi Bayfront, Corpus Christi, TX AGENCY: Coast Guard, DHS. ACTION: Temporary Final rule. SUMMARY: The Coast Guard is establishing a temporary Special Local Regulation in the Corpus Christi Bayfront area...

  1. Minimal Absent Words in Four Human Genome Assemblies

    PubMed Central

    Garcia, Sara P.; Pinho, Armando J.

    2011-01-01

    Minimal absent words have been computed in genomes of organisms from all domains of life. Here, we aim to contribute to the catalogue of human genomic variation by investigating the variation in number and content of minimal absent words within a species, using four human genome assemblies. We compare the reference human genome GRCh37 assembly, the HuRef assembly of the genome of Craig Venter, the NA12878 assembly from cell line GM12878, and the YH assembly of the genome of a Han Chinese individual. We find the variation in number and content of minimal absent words between assemblies more significant for large and very large minimal absent words, where the biases of sequencing and assembly methodologies become more pronounced. Moreover, we find generally greater similarity between the human genome assemblies sequenced with capillary-based technologies (GRCh37 and HuRef) than between the human genome assemblies sequenced with massively parallel technologies (NA12878 and YH). Finally, as expected, we find the overall variation in number and content of minimal absent words within a species to be generally smaller than the variation between species. PMID:22220210

  2. Enhancing Writing Pedagogy with Learner Corpus Data

    ERIC Educational Resources Information Center

    Cotos, Elena

    2014-01-01

    Learner corpora have become prominent in language teaching and learning, enhancing data-driven learning (DDL) pedagogy by promoting "learning driven data" in the classroom. This study explores the potential of a local learner corpus by investigating the effects of two types of DDL activities, one relying on a native-speaker corpus (NSC)…

  3. Network Analysis with the Enron Email Corpus

    ERIC Educational Resources Information Center

    Hardin, J. S.; Sarkis, G.; URC, P. .

    2015-01-01

    We use the Enron email corpus to study relationships in a network by applying six different measures of centrality. Our results came out of an in-semester undergraduate research seminar. The Enron corpus is well suited to statistical analyses at all levels of undergraduate education. Through this article's focus on centrality, students can explore…

  4. 32 CFR 516.20 - Habeas Corpus.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 3 2010-07-01 2010-07-01 true Habeas Corpus. 516.20 Section 516.20 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY AID OF CIVIL AUTHORITIES AND PUBLIC RELATIONS LITIGATION Reporting Legal Proceedings to HQDA § 516.20 Habeas Corpus. (a) General. A soldier...

  5. Absent and Accounted For: Absenteeism and Cooperative Learning

    ERIC Educational Resources Information Center

    Koppenhaver, G. D.

    2006-01-01

    In a small section collaborative learning environment where student work teams promote mutual learning about investments, students limit the opportunity to learn from other students if they are absent from class. Absenteeism not only denies the student the opportunity to learn from others but also denies other members of the student's work team…

  6. The Production of Present and Absent Presences in Education

    ERIC Educational Resources Information Center

    Frelin, Anneli; Grannäs, Jan

    2013-01-01

    Drawing on the distinction between absent and present presences, this article contributes to our understanding of how new managerial and performative discourses are played out in a secondary school context in Sweden. The consequences of numerous educational reforms during the last 20 years include a surge of new independent schools and increased…

  7. Vampire Selfie: A Curious Case of an Absent Reflection

    ERIC Educational Resources Information Center

    Grossman, Joshua M.

    2014-01-01

    This article presents a puzzle for the optics section of an introductory course on reflections. A teacher could ask students to explain the phenomenon of the "vampire selfie" or the absent reflection. How could that be? What physics caused this curious phenomenon? The article explains light refraction and its effect on what we see and…

  8. PHACE syndrome and congenitally absent thyroid gland at MR imaging.

    PubMed

    Mamlouk, Mark D; Yu, John-Paul J; Asch, Sarah; Mathes, Erin F

    2016-01-01

    PHACE syndrome is a rare neurocutaneous disorder characterized by posterior fossa malformations, hemangiomas, arterial anomalies, cardiac defects, and abnormalities of the eye. Thyroid disorders associated with PHACE syndrome have been described, although there are limited reports of this rare occurrence. We report a case of PHACE syndrome with congenital hypothyroidism in an infant, for which absent thyroid gland was diagnosed at magnetic resonance imaging.

  9. Kaufman oculo-cerebro-facial syndrome in a child with small and absent terminal phalanges and absent nails.

    PubMed

    Kariminejad, Ariana; Ajeawung, Norbert Fonya; Bozorgmehr, Bita; Dionne-Laporte, Alexandre; Molidperee, Sirinart; Najafi, Kimia; Gibbs, Richard A; Lee, Brendan H; Hennekam, Raoul C; Campeau, Philippe M

    2017-04-01

    Kaufman oculo-cerebro-facial syndrome (KOS) is caused by recessive UBE3B mutations and presents with microcephaly, ocular abnormalities, distinctive facial morphology, low cholesterol levels and intellectual disability. We describe a child with microcephaly, brachycephaly, hearing loss, ptosis, blepharophimosis, hypertelorism, cleft palate, multiple renal cysts, absent nails, small or absent terminal phalanges, absent speech and intellectual disability. Syndromes that were initially considered include DOORS syndrome, Coffin-Siris syndrome and Dubowitz syndrome. Clinical investigations coupled with karyotype analysis, array-comparative genomic hybridization, exome and Sanger sequencing were performed to characterize the condition in this child. Sanger sequencing was negative for the DOORS syndrome gene TBC1D24 but exome sequencing identified a homozygous deletion in UBE3B (NM_183415:c.3139_3141del, p.1047_1047del) located within the terminal portion of the HECT domain. This finding coupled with the presence of characteristic features such as brachycephaly, ptosis, blepharophimosis, hypertelorism, short palpebral fissures, cleft palate and developmental delay allowed us to make a diagnosis of KOS. In conclusion, our findings highlight the importance of considering KOS as a differential diagnosis for patients under evaluation for DOORS syndrome and expand the phenotype of KOS to include small or absent terminal phalanges, nails, and the presence of hallux varus and multicystic dysplastic kidneys.

  10. Growth and development of the corpus luteum.

    PubMed

    Reynolds, L P; Redmer, D A

    1999-01-01

    The mammalian corpus luteum, which plays a central role in the reproductive process because of its production of hormones such as progesterone, is an exceptionally dynamic organ. Growth and development of the corpus luteum are extremely rapid, and even when the corpus luteum is functionally mature cellular turnover remains high. Associated with this high rate of cell turnover, the mature corpus luteum receives the greatest blood supply per unit tissue of any organ, and also exhibits a relatively high metabolic rate. Central to the growth and development of the corpus luteum, therefore, is luteal vascular growth, which appears to be regulated primarily by the angiogenic growth factors, basic fibroblast growth factor and vascular endothelial growth factor. In addition, the corpus luteum is a complex tissue composed of parenchymal (small and large steroidogenic) and nonparenchymal (for example fibroblasts, vascular smooth muscle, pericytes and endothelial) cells. Recent studies evaluating the expression, location and regulation of gap junctions in the corpus luteum indicate an important role of gap junctional intercellular communication in the coordination of function among these diverse cell types during luteal growth and development. These studies will lead to an improved understanding not only of luteal function but also of tissue growth and development in general.

  11. Medroxyprogesterone in Treating Patients With Endometrioid Adenocarcinoma of the Uterine Corpus

    ClinicalTrials.gov

    2016-03-17

    Endometrial Adenocarcinoma; Endometrial Adenosquamous Carcinoma; Endometrial Endometrioid Adenocarcinoma, Variant With Squamous Differentiation; Recurrent Uterine Corpus Carcinoma; Stage I Uterine Corpus Cancer; Stage II Uterine Corpus Cancer; Stage III Uterine Corpus Cancer; Stage IV Uterine Corpus Cancer

  12. Apes Communicate about Absent and Displaced Objects: Methodology Matters

    PubMed Central

    Lyn, Heidi; Russell, Jamie L.; Leavens, David A.; Bard, Kim A.; Boysen, Sarah T.; Schaeffer, Jennifer A.; Hopkins, William D.

    2013-01-01

    Displaced reference is the ability to refer to an item that has been moved (displaced) in space and/or time, and has been called one of the true hallmarks of referential communication. Several studies suggest that nonhuman primates have this capability, but a recent experiment concluded that in a specific situation (absent entities) human infants display displaced reference but chimpanzees do not. Here we show that chimpanzees and bonobos of diverse rearing histories are capable of displaced reference to absent and displaced objects. It is likely that some of the conflicting findings from animal cognition studies are due to relatively minor methodological differences, but are compounded by interpretation errors. Comparative studies are of great importance in elucidating the evolution of human cognition, however, greater care must be taken with methodology and interpretation for these studies to accurately reflect species differences. PMID:23681052

  13. Congenital hypogonadotropic hypogonadism: implications of absent mini-puberty.

    PubMed

    Dwyer, Andrew A; Jayasena, Channa N; Quinton, Richard

    2016-06-01

    The phenomenon known as "mini-puberty" refers to activation of the neonatal hypothalamo-pituitary axis causing serum concentrations of gonadotrophins and testosterone (T) to approach adult male levels. This early neonatal period is a key proliferative window for testicular germ cells and immature Sertoli cells. Although failure to spontaneously initiate (adolescent) puberty is the most evident consequence of a defective gonadotropin-releasing hormone (GnRH) neurosecretory network, absent mini-puberty is also likely to have a major impact on the reproductive phenotype of men with congenital hypogonadotrophic hypogonadism (CHH). Furthermore, the phase of male mini-puberty represents a key window-of-opportunity to identify congenital GnRH deficiency (either isolated CHH, or as part of combined pituitary hormone deficiency) in childhood. Among male neonates exhibiting "red flag" indicators for CHH (i.e. maldescended testes with or without cryptorchidism) a single serum sample (between 4-8 weeks of life) can pinpoint congenital GnRH deficiency far more rapidly and with much greater accuracy than dynamic tests performed in later childhood or adolescence. Potential consequences for missing absent mini-puberty in a male neonate include the lack of monitoring of pubertal progression/lack of progression, and the missed opportunity for early therapeutic intervention. This article will review our current understanding of the mechanisms and clinical consequences of mini-puberty. Furthermore, evidence for the optimal clinical management of patients with absent mini-puberty will be discussed.

  14. [Medicine and astrology in Arnau's corpus].

    PubMed

    Giralt, Sebastià

    2006-01-01

    The role of astrology in Arnau de Vilanova's medical work is revisited with special attention to the problems of authorship posed by the astrological writings of Arnau's corpus and to their hypothetical chronology.

  15. 32 CFR 516.20 - Habeas Corpus.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... any civil officer having authority to apprehend offenders under the laws of the United States or of... the nature of a writ of habeas corpus, the SJA or legal adviser will immediately report the matter...

  16. Learner-Corpus Interaction: A Locus of Microgenesis in Corpus-Assisted L2 Writing

    ERIC Educational Resources Information Center

    Park, Kwanghyun

    2012-01-01

    This paper examines the processes through which learners interact with a corpus system and microgenetic development emerges from the interaction. The corpus system described in this paper is capable of retrieving highly relevant textual examples tailored to individual needs. Data were collected from an undergraduate ESL composition course in North…

  17. The Absent Interpreter in Administrative Detention Center Medical Units.

    PubMed

    Rondeau-Lutz, Murielle; Weber, Jean-Christophe

    2017-03-01

    The particular situation of the French administrative detention center (ADC) medical units appears to be an exemplary case to study the difficulties facing medical practice. Indeed, the starting point of our inquiry was an amazing observation that needed to be addressed and understood: why are professional interpreters so seldom requested in ADC medical units, where one would expect that they would be "naturally" present? Aiming to fully explore the meanings of the "absent interpreter", this article takes into account the possible meanings of this situation: the recourse to professional interpreters in France is far from expected given cumulative evidence of its benefits; perceptions of illegal immigrants and medical habitus itself may both hamper the use of a third party; the ADCs are a very stressful place for healthcare professionals, with conflicting missions, political issues enmeshed with medical goals, and heavy affective burden that may lead to self-protection. Silencing voices of suffering others might be seen as the hidden indecent truth of the "absent interpreter". These reflections open a window to a larger issue with regard to the full range of medicine: what are the place, the role and the function of patient's words and narratives in contemporary medicine? The highly invested somatic perspective and its political corollary giving primacy to bare life harbor potential risks of obscuring speeches and undervaluing narratives.

  18. Absent without leave; a neuroenergetic theory of mind wandering

    PubMed Central

    Killeen, Peter R.

    2013-01-01

    Absent minded people are not under the control of task-relevant stimuli. According to the Neuroenergetics Theory of attention (NeT), this lack of control is often due to fatigue of the relevant processing units in the brain caused by insufficient resupply of the neuron's preferred fuel, lactate, from nearby astrocytes. A simple drift model of information processing accounts for response-time statistics in a paradigm often used to study inattention, the Sustained Attention to Response Task (SART). It is suggested that errors and slowing in this fast-paced, response-engaging task may have little to due with inattention. Slower-paced and less response-demanding tasks give greater license for inattention—aka absent-mindedness, mind-wandering. The basic NeT is therefore extended with an ancillary model of attentional drift and recapture. This Markov model, called NEMA, assumes probability λ of lapses of attention from 1 s to the next, and probability α of drifting back to the attentional state. These parameters measure the strength of attraction back to the task (α), or away to competing mental states or action patterns (λ); their proportion determines the probability of the individual being inattentive at any point in time over the long run. Their values are affected by the fatigue of the brain units they traffic between. The deployment of the model is demonstrated with a data set involving paced responding. PMID:23847559

  19. Formation of excitatory and inhibitory associations between absent events

    PubMed Central

    Holland, Peter C.; Sherwood, Andrew

    2010-01-01

    Considerable evidence indicates that associations may be formed between two events even when one or both of them is absent at the time of learning. Previously, some researchers asserted that excitatory associations are formed when associatively-activated representations for two events are paired, whereas others claimed that inhibitory associations are formed. In three experiments we investigated the nature of tone-sucrose learning when associatively-activated representations of those events were paired in the absence of either of the events themselves. Experiment 1 found substantial excitatory learning when the tone surrogate preceded the sucrose surrogate in training. Experimental 2 evaluated other accounts for the results of Experiment 1, and Experiment 3 found evidence for inhibitory tone-sucrose learning when the tone and sucrose surrogates were presented in simultaneous or backward order. The results indicated that the nature of representation-mediated learning is influenced by some of the same variables as more standard associative learning. PMID:18665716

  20. Volatiles emitted from single flower buds of the lilium longiflorum × L. callosum interspecific hybrid and its parents

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This research was initiated to analyze the volatiles emitted from a single flower bud of Lilium longiflorum Thunb., L. callosum Sieb. et Zucc., and interspecific hybrids of L. longiflorum × L. callosum (L. longi × L. cal IH). Volatiles, collected automatically every 6-hour intervals at 20oC before ...

  1. Thrombocytopenia-absent radius syndrome: a clinical genetic study

    PubMed Central

    Greenhalgh, K; Howell, R; Bottani, A; Ancliff, P; Brunner, H; Verschuuren-Bemel..., C; Vernon, E; Brown, K; Newbury-Ecob, R

    2002-01-01

    The thrombocytopenia-absent radius (TAR) syndrome is a congenital malformation syndrome characterised by bilateral absence of the radii and a thrombocytopenia. The lower limbs, gastrointestinal, cardiovascular, and other systems may also be involved. Shaw and Oliver in 1959 were the first to describe this condition, but it was Hall et al in 1969 who reported the first major series of patients. Since then most reports have been based on single or small numbers of cases. We report the results of a clinical study looking at the phenotype of 34 patients with TAR syndrome. All cases had a documented thrombocytopenia and bilateral radial aplasia, 47% had lower limb anomalies, 47% cow's milk intolerance, 23% renal anomalies, and 15% cardiac anomalies. Congenital anomalies not previously described in association with TAR syndrome included facial capillary haemangiomata, intracranial vascular malformation, sensorineural hearing loss, and scoliosis. Karyotype analysis, chromosome breakage studies including premature centromeric separation and fluorescence in situ hybridisation studies looking for a deletion of chromosome 22q11 were undertaken. Two abnormal karyotypes were identified. PMID:12471199

  2. Absent in melanoma 2 proteins in the development of cancer.

    PubMed

    Choubey, Divaker

    2016-12-01

    Recent studies utilizing chemical-induced colitis-associated and sporadic colon cancer in mouse models indicated a protective role for absent in melanoma 2 (Aim2) in colon epithelial cells. Accordingly, mutations in the human AIM2 gene have been found in colorectal cancer (CRC), and reduced expression of AIM2 in CRC is associated with its progression. Furthermore, the overexpression of AIM2 protein in human cancer cell lines inhibits cell proliferation. Interferon-inducible Aim2 and AIM2 are members of the PYHIN (PYRIN and HIN domain-containing) protein family and share ~57 % amino acid identity. The family also includes murine p202, human PYRIN-only protein 3, and IFI16, which negatively regulate Aim2/AIM2 functions. Because the CRC incidence and mortality rates are higher among men compared with women and the expression of Aim2/AIM2 proteins and their regulators is dependent upon age, gender, and sex hormones, we discuss the potential roles of Aim2/AIM2 in the development of cancer. An improved understanding of the biological functions of the AIM2 in the development of CRC will likely identify new therapeutic approaches to treat patients.

  3. Distinct Biochemical Activities of Eyes absent During Drosophila Eye Development.

    PubMed

    Jin, Meng; Mardon, Graeme

    2016-03-16

    Eyes absent (Eya) is a highly conserved transcriptional coactivator and protein phosphatase that plays vital roles in multiple developmental processes from Drosophila to humans. Eya proteins contain a PST (Proline-Serine-Threonine)-rich transactivation domain, a threonine phosphatase motif (TPM), and a tyrosine protein phosphatase domain. Using a genomic rescue system, we find that the PST domain is essential for Eya activity and Dac expression, and the TPM is required for full Eya function. We also find that the threonine phosphatase activity plays only a minor role during Drosophila eye development and the primary function of the PST and TPM domains is transactivation that can be largely substituted by the heterologous activation domain VP16. Along with our previous results that the tyrosine phosphatase activity of Eya is dispensable for normal Eya function in eye formation, we demonstrate that a primary function of Eya during Drosophila eye development is as a transcriptional coactivator. Moreover, the PST/TPM and the threonine phosphatase activity are not required for in vitro interaction between retinal determination factors. Finally, this work is the first report of an Eya-Ey physical interaction. These findings are particularly important because they highlight the need for an in vivo approach that accurately dissects protein function.

  4. The Need for a Speech Corpus

    ERIC Educational Resources Information Center

    Campbell, Dermot F.; McDonnell, Ciaran; Meinardi, Marti; Richardson, Bunny

    2007-01-01

    This paper outlines the ongoing construction of a speech corpus for use by applied linguists and advanced EFL/ESL students. In the first part, sections 1-4, the need for improvements in the teaching of listening skills and pronunciation practice for EFL/ESL students is noted. It is argued that the use of authentic native-to-native speech is…

  5. Inflation Metaphor in the TIME Magazine Corpus

    ERIC Educational Resources Information Center

    Hu, Chunyu; Liu, Huijie

    2016-01-01

    A historical perspective on economy metaphor can shed new lights on economic thoughts. Based on the TIME Magazine Corpus (TMC), this paper investigates inflation metaphor over 83 years and compares findings against the economic data over the relatively corresponding period. The results show how inflation, an abstract concept and a normal economic…

  6. 33 CFR 165.808 - Corpus Christi Ship Channel, Corpus Christi, TX, safety zone.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Petroleum Gas, the waters within a 500 yard radius of the LPG carrier while the vessel transits the Corpus... within a 500 yard radius of the LPG carrier while the vessel departs the LPG facility and transits...

  7. Using a Corpus in a 300-Level Spanish Grammar Course

    ERIC Educational Resources Information Center

    Benavides, Carlos

    2015-01-01

    The present study examined the use and effectiveness of a large corpus--the Corpus del Español (Davies, 2002)--in a 300-level Spanish grammar university course. Students conducted hands-on corpus searches with the goal of finding concordances containing particular types of collocations (combinations of words that tend to co-occur) and tokens (any…

  8. Imaging spectrum of pediatric corpus callosal pathology: a pictorial review.

    PubMed

    Hyun Yoo, Jeong; Hunter, Jill

    2013-04-01

    A wide spectrum of pediatric corpus callosal diseases can occur in the pediatric age group. Cross-sectional magnetic resonance imaging plays an important role in the diagnosis of these patients. We reviewed our imaging record and collected cases of corpus callosal pathology. The purpose of this review is to illustrate the imaging features of various corpus callosal lesions encountered in children.

  9. 33 CFR 110.75 - Corpus Christi Bay, Tex.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Corpus Christi Bay, Tex. 110.75... ANCHORAGE REGULATIONS Special Anchorage Areas § 110.75 Corpus Christi Bay, Tex. (a) South area. Southward of... said breakwater; and eastward of the Corpus Christi sea wall....

  10. Can a Graded Reader Corpus Provide "Authentic" Input?

    ERIC Educational Resources Information Center

    Allan, Rachel

    2009-01-01

    In addition to their intended purpose, graded reader texts can be made into a corpus appropriate for use with lower-level learners. Here I consider using such a corpus for data-driven learning (DDL), to make this approach more accessible to intermediate level students. However, how far does grading the corpus in this way compromise the…

  11. EFL Students' Perceptions of Corpus-Tools as Writing References

    ERIC Educational Resources Information Center

    Lai, Shu-Li

    2015-01-01

    A number of studies have suggested the potentials of corpus tools in vocabulary learning. However, there are still some concerns. Corpus tools might be too complicated to use; example sentences retrieved from corpus tools might be too difficult to understand; processing large number of sample sentences could be challenging and time-consuming;…

  12. Developing a Disease Outbreak Event Corpus

    PubMed Central

    Kawazoe, Ai; Chanlekha, Hutchatai; Collier, Nigel

    2010-01-01

    Background In recent years, there has been a growth in work on the use of information extraction technologies for tracking disease outbreaks from online news texts, yet publicly available evaluation standards (and associated resources) for this new area of research have been noticeably lacking. Objective This study seeks to create a “gold standard” data set against which to test how accurately disease outbreak information extraction systems can identify the semantics of disease outbreak events. Additionally, we hope that the provision of an annotation scheme (and associated corpus) to the community will encourage open evaluation in this new and growing application area. Methods We developed an annotation scheme for identifying infectious disease outbreak events in news texts. An event─in the context of our annotation scheme─consists minimally of geographical (eg, country and province) and disease name information. However, the scheme also allows for the rich encoding of other domain salient concepts (eg, international travel, species, and food contamination). Results The work resulted in a 200-document corpus of event-annotated disease outbreak reports that can be used to evaluate the accuracy of event detection algorithms (in this case, for the BioCaster biosurveillance online news information extraction system). In the 200 documents, 394 distinct events were identified (mean 1.97 events per document, range 0-25 events per document). We also provide a download script and graphical user interface (GUI)-based event browsing software to facilitate corpus exploration. Conclusion In summary, we present an annotation scheme and corpus that can be used in the evaluation of disease outbreak event extraction algorithms. The annotation scheme and corpus were designed both with the particular evaluation requirements of the BioCaster system in mind as well as the wider need for further evaluation resources in this growing research area. PMID:20876049

  13. Twelve- and 16-Month-Old Infants Recognize Properties of Mentioned Absent Things

    ERIC Educational Resources Information Center

    Saylor, Megan M.

    2004-01-01

    Absent reference comprehension is a critical achievement of early development, yet little is known about its emergence. In the current study, 12- and 16-month-old infants' recognition of properties of mentioned absent things was used as an index of absent reference comprehension. Infants were presented with displays matching the color and prior…

  14. Pituitary regulation of corpus luteum progesterone secretion in cyclic rats.

    PubMed

    Sánchez-Criado, J E; López, F; Aguilar, E

    1986-09-01

    Pituitary LH and PRL secretion during the early postovulatory period of the rat estrous cycle seem to affect the corpus luteum (CL) autonomy to secrete progesterone. Thus, while PRL would act luteotropically, LH would be luteolytic. To further investigate these facts, 4-day cyclic rats, treated with either 1 mg bromocriptine (CB) or 0.25 ml 70% ethanol (ETOH) at 1600 h on estrus, were injected with 0.5 ml of either an anti-LH serum (LHAS) or normal horse serum (NHS) at 0800 h on metestrus. Rats treated at 0800 h on metestrus with both, CB and LHAS, were also used. To verify through a different procedure the effect of LH and/or PRL deprivation in estrous cycle CL progesterone secretion, hypophysectomy (HYPOX) and sham HYPOX (SHAM) were done at 0800 h on metestrus in either CB- or ETOH-injected rats at 1600 h on estrus. Hypophysectomized rats at 1600 h on estrus were also used. Progesterone secretion was prolonged up to 0800 h on diestrus in those rats deprived of LH from 0800 h on metestrus (ETOH/LHAS, -/CB + LHAS, ETOH/HYPOX) compared with controls (ETOH/NHS, ETOH/SHAM). This luteotropic effect was absent in those rats lacking estrous afternoon PRL (CB/LHAS, CB/HYPOX, HYPOX/-). No effect on CL progesterone secretion was detected in those rats exclusively deprived of PRL on the afternoon of estrus (CB/NHS, CB/SHAM). These results suggest that in the absence of the protective effects of PRL secretion on the afternoon of estrus, rat CL become extremely sensitive to the luteolytic effects of early diestrous LH levels, and this results in 4-day estrous cycles.

  15. Creation of a new longitudinal corpus of clinical narratives.

    PubMed

    Kumar, Vishesh; Stubbs, Amber; Shaw, Stanley; Uzuner, Özlem

    2015-12-01

    The 2014 i2b2/UTHealth Natural Language Processing (NLP) shared task featured a new longitudinal corpus of 1304 records representing 296 diabetic patients. The corpus contains three cohorts: patients who have a diagnosis of coronary artery disease (CAD) in their first record, and continue to have it in subsequent records; patients who do not have a diagnosis of CAD in the first record, but develop it by the last record; patients who do not have a diagnosis of CAD in any record. This paper details the process used to select records for this corpus and provides an overview of novel research uses for this corpus. This corpus is the only annotated corpus of longitudinal clinical narratives currently available for research to the general research community.

  16. The Hebrew CHILDES corpus: transcription and morphological analysis

    PubMed Central

    Albert, Aviad; MacWhinney, Brian; Nir, Bracha

    2014-01-01

    We present a corpus of transcribed spoken Hebrew that reflects spoken interactions between children and adults. The corpus is an integral part of the CHILDES database, which distributes similar corpora for over 25 languages. We introduce a dedicated transcription scheme for the spoken Hebrew data that is sensitive to both the phonology and the standard orthography of the language. We also introduce a morphological analyzer that was specifically developed for this corpus. The analyzer adequately covers the entire corpus, producing detailed correct analyses for all tokens. Evaluation on a new corpus reveals high coverage as well. Finally, we describe a morphological disambiguation module that selects the correct analysis of each token in context. The result is a high-quality morphologically-annotated CHILDES corpus of Hebrew, along with a set of tools that can be applied to new corpora. PMID:25419199

  17. The Ubuntu Chat Corpus for Multiparticipant Chat Analysis

    DTIC Science & Technology

    2013-03-01

    as well as support in non- English languages . All messages are logged and kept in a public archive at http://irclogs.ubuntu.com/. We created a corpus...seen in a non-technical chat channel. Finally, the corpus contains channels in languages other than English , yet the channels cover the same general...with most fo- cusing on English . This corpus provides a great resource for investigating techniques on non- English languages and for investigating

  18. What's In a Note: Construction of a Suicide Note Corpus.

    PubMed

    Pestian, John P; Matykiewicz, Pawel; Linn-Gust, Michelle

    2012-01-01

    This paper reports on the results of an initiative to create and annotate a corpus of suicide notes that can be used for machine learning. Ultimately, the corpus included 1,278 notes that were written by someone who died by suicide. Each note was reviewed by at least three annotators who mapped words or sentences to a schema of emotions. This corpus has already been used for extensive scientific research.

  19. Selective gene expression by rat gastric corpus epithelium

    PubMed Central

    Goebel, M.; Stengel, A.; Sachs, G.

    2011-01-01

    The gastrointestinal (GI) tract is divided into several segments that have distinct functional properties, largely absorptive. The gastric corpus is the only segment thought of as largely secretory. Microarray hybridization of the gastric corpus mucosal epithelial cells was used to compare gene expression with other segments of the columnar GI tract followed by statistical data subtraction to identify genes selectively expressed by the rat gastric corpus mucosa. This provides a means of identifying less obvious specific functions of the corpus in addition to its secretion-related genes. For example, important properties found by this GI tract comparative transcriptome reflect the energy demand of acid secretion, a role in lipid metabolism, the large variety of resident neuroendocrine cells, responses to damaging agents and transcription factors defining differentiation of its epithelium. In terms of overlap of gastric corpus genes with the rest of the GI tract, the distal small bowel appears to express many of the gastric corpus genes in contrast to proximal small and large bowel. This differential map of gene expression by the gastric corpus epithelium will allow a more detailed description of major properties of the gastric corpus and may lead to the discovery of gastric corpus cell differentiation genes and those mis-regulated in gastric carcinomas. PMID:21177383

  20. Corpus Callosum Function in Verbal Dichotic Listening: Inferences from a Longitudinal Follow-Up of Relapsing-Remitting Multiple Sclerosis Patients

    ERIC Educational Resources Information Center

    Gadea, Marien; Marti-Bonmati, Luis; Arana, Estanislao; Espert, Raul; Salvador, Alicia; Casanova, Bonaventura

    2009-01-01

    This study conducted a follow-up of 13 early-onset slightly disabled Relapsing-Remitting Multiple Sclerosis (RRMS) patients within an year, evaluating both CC area measurements in a midsagittal Magnetic Resonance (MR) image, and Dichotic Listening (DL) testing with stop consonant vowel (C-V) syllables. Patients showed a significant progressive…

  1. Functional consequences of a section of the anterior part of the body of the corpus callosum: evidence from an interhemispheric transcallosal approach.

    PubMed

    Peltier, Johann; Roussel, Martine; Gerard, Yasmina; Lassonde, Maryse; Deramond, Hervé; Le Gars, Daniel; Gars, Daniel Le; De Beaumont, Louis; Beaumont, Louis De; Godefroy, Olivier

    2012-09-01

    The aim of this study was to determine the neuropsychological consequences of a middle interhemispheric approach for the removal of tumors of the third or lateral ventricles. A retrospective analysis of eight callosotomized patients for ventricular tumors (three males/five females; mean age: 48.7 ± 11.2 years; education level: 11.9 ± 2.9 years) and eight healthy subjects was performed. An extensive neuropsychological test battery was used to evaluate global intellectual efficiency, memory capacities, executive functions, and interhemispheric transfer of a procedural learning task (serial reaction time task/SRTT). Neuropsychological results showed that: (1) five of eight patients operated through a middle transcallosal approach had disturbances of verbal or visual memory; (2) three of eight patients displayed a dysexecutive cognitive syndrome(two of eight of whom presenting with a deficit of verbal fluency); (3) two of eight patients presented a dysexecutive behavior syndrome; and (4) with regard to the SRTT, although all participants learned the task, in contrast to controls, the callosotomized patients showed an increase in reaction times and an absence of interhemispheric transfer of learning from one hand to the other. The transcallosal approach transects a large number of callosal fibers. This damage accounts for the deficits of memory, the dysexecutive cognitive and behavioral syndrome, and disturbances in interhemispheric transfer of learning.

  2. Renal tubular dysgenesis, absent nipples, and multiple malformations in three brothers: a new, lethal syndrome.

    PubMed

    Hisama, F M; Reyes-Mugica, M; Wargowski, D S; Thompson, K J; Mahoney, M J

    1998-12-04

    We report on three brothers with renal tubular dysgenesis and absent nipples, each also had other malformations including pre-auricular pits and a preauricular tag, branchial clefts, choanal atresia, pulmonary lobation anomaly, ventricular septal defect, type IIB interrupted aortic arch, absent gallbladder, absent thymus, parathyroid gland, accessory spleen, imperforate anus, clinodactyly, and broad digits and small nails. All three infants died neonatally. This pattern of clinical malformations appears to be a previously unreported syndrome.

  3. Corpus cavernosum abscess after Winter procedure performance

    PubMed Central

    Paladino, Joao Roberto; Nascimento, Fabio Jose; Gromatsky, Celso; Pompeo, Antonio Carlos Lima

    2014-01-01

    A 23-year-old male patient with sickle-cell disease reported his third episode of priapism complicated by the presence of a corpus cavernosum abscess after the performance of a Winter procedure 20 days prior to his presentation. While in hospital for 11 days, two penile needle aspirations and three surgical drainages were performed with associated antibiotic therapy. He evolved with erectile dysfunction refractory to drug therapy and his infectious condition improved. An early penile prosthesis implantation followed after the use of a vacuum pump in an attempt to decrease the fibrotic process of the corpora cavernosa. Final results were positive. PMID:24515231

  4. Corpus-Assisted Creative Writing: Introducing Intermediate Italian Learners to a Corpus as a Reference Resource

    ERIC Educational Resources Information Center

    Kennedy, Claire; Miceli, Tiziana

    2010-01-01

    In much of the literature on the exploitation of corpora for language learning, the learners are viewed as researchers, who formulate and test their own hypotheses about language use. Having identified difficulties encountered in corpus investigations by our intermediate-level students of Italian in a previous study, we have designed a…

  5. Turner Syndrome and apparent absent uterus: a case report and review of the literature.

    PubMed

    Akierman, Sarah V; Skappak, Christopher D; Girgis, Rose; Ho, Josephine

    2013-01-01

    We report on a patient who initially presented with delayed puberty and an absent uterus on imaging with ultrasound and MRI. She was subsequently diagnosed with Turner Syndrome. Turner Syndrome typically presents with early loss of ovarian function and should be considered when primary ovarian insufficiency is present with apparent absent uterus on imaging. Follow-up imaging of the apparent absent uterus post-estrogen replacement therapy is important to confirm a normal uterus. A diagnosis of an absent uterus can be psychologically traumatic for patients and families, and can have significant implications for future fertility options.

  6. Causal Attributions as Predictors of Academic Achievement in Father-Absent Children.

    ERIC Educational Resources Information Center

    Salzman, Stephanie A.

    The purpose of this study was to examine the potential impact of maternal attributions and self-attributions on the academic achievement of father-absent children in comparison to commonly identified family interaction and demographic variables. Subjects included 33 male and 34 female father-absent sixth graders (mean age of 11.6 years) and their…

  7. Asymmetrical Sample Training Produces Asymmetrical Retention Functions in Feature-Present/Feature-Absent Matching in Pigeons

    ERIC Educational Resources Information Center

    Grant, Douglas S.; Blatz, Craig W.

    2004-01-01

    Pigeons were trained in a matching task in which samples involved presentation of a white line on a green background (feature-present) or on an otherwise dark key (feature-absent). After asymmetrical training in which one group was initially trained with the feature-present sample and another was initially trained with the feature-absent sample,…

  8. 42 CFR 410.175 - Alien absent from the United States.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 2 2014-10-01 2014-10-01 false Alien absent from the United States. 410.175... Alien absent from the United States. (a) Medicare does not pay Part B benefits for services furnished to... during the first full calendar month the alien is back in the United States....

  9. 42 CFR 410.175 - Alien absent from the United States.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 2 2010-10-01 2010-10-01 false Alien absent from the United States. 410.175... Alien absent from the United States. (a) Medicare does not pay Part B benefits for services furnished to... during the first full calendar month the alien is back in the United States....

  10. 42 CFR 410.175 - Alien absent from the United States.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 2 2013-10-01 2013-10-01 false Alien absent from the United States. 410.175... Alien absent from the United States. (a) Medicare does not pay Part B benefits for services furnished to... during the first full calendar month the alien is back in the United States....

  11. 42 CFR 410.175 - Alien absent from the United States.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 2 2012-10-01 2012-10-01 false Alien absent from the United States. 410.175... Alien absent from the United States. (a) Medicare does not pay Part B benefits for services furnished to... during the first full calendar month the alien is back in the United States....

  12. 42 CFR 410.175 - Alien absent from the United States.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 2 2011-10-01 2011-10-01 false Alien absent from the United States. 410.175... Alien absent from the United States. (a) Medicare does not pay Part B benefits for services furnished to... during the first full calendar month the alien is back in the United States....

  13. Successful Black Men from Absent-Father Homes and Their Resilient Single Mothers: A Phenomenological Study

    ERIC Educational Resources Information Center

    Wilson, Angie D.; Henriksen, Richard C.; Bustamante, Rebecca; Irby, Beverly

    2016-01-01

    The phenomenon of absent fathers is a common occurrence in today's homes that appears to be escalating, especially in Black households across the United States. The purpose of this study was to describe the lived experiences of successful Black men who were raised in absent-father homes as well as the lived experiences of their resilient single…

  14. Disneyland Dads, Disneyland Moms? How Nonresident Parents Spend Time with Absent Children.

    ERIC Educational Resources Information Center

    Stewart, Susan D.

    1999-01-01

    Examines gender differences in how nonresident parents spend time with their absent children. Results suggest that nonresident mothers and fathers exhibit a similar pattern of participation in activities with their absent children. Most nonresident parents either engage in only leisure activities with their children or have no contact. (Author/MKA)

  15. The Use of a Corpus in Contrastive Studies.

    ERIC Educational Resources Information Center

    Filipovic, Rudolf

    1973-01-01

    Before beginning the Serbocroatian-English Contrastive Project, it was necessary to determine whether to base the analysis on a corpus or on native intuitions. It seemed that the best method would combine the theoretical and the empirical. A translation method based on a corpus of text was adopted. The Brown University "Standard Sample of…

  16. Developing Corpus-Based Materials to Teach Pragmatic Routines

    ERIC Educational Resources Information Center

    Bardovi-Harlig, Kathleen; Mossman, Sabrina; Vellenga, Heidi E.

    2015-01-01

    This article describes how to develop teaching materials for pragmatics based on authentic language by using a spoken corpus. The authors show how to use the corpus in conjunction with textbooks to identify pragmatic routines for speech acts and how to extract appropriate language samples and adapt them for classroom use. They demonstrate how to…

  17. Corpus-Based Learning of Cantonese for Mandarin Speakers

    ERIC Educational Resources Information Center

    Lee, John; Wong, Tak-Sum

    2014-01-01

    This paper reports our experience in using a parallel corpus to teach Cantonese, a variety of Chinese spoken in Hong Kong, as a second language. The parallel corpus consists of pairs of word-aligned sentences in Cantonese and Mandarin Chinese, drawn from television programs in Hong Kong (Lee, 2011). We evaluated our pedagogical approach with…

  18. Use of "Google Scholar" in Corpus-Driven EAP Research

    ERIC Educational Resources Information Center

    Brezina, Vaclav

    2012-01-01

    This primarily methodological article makes a proposition for linguistic exploration of textual resources available through the "Google Scholar" search engine. These resources ("Google Scholar virtual corpus") are significantly larger than any existing corpus of academic writing. "Google Scholar", however, was not designed for linguistic searches…

  19. Codeswitching, Borrowing and Mixing in a Corpus of Xhosa English

    ERIC Educational Resources Information Center

    de Klerk, Vivian

    2006-01-01

    The paper analyses selected aspects of the codeswitching behaviour in a spoken corpus of the English of 326 people, all of them mother-tongue speakers of Xhosa (a local African language in South Africa), and all of whom would see themselves as Xhosa/English bilinguals. The corpus comprises approximately 550,000 transcribed words of spontaneous,…

  20. Corpus-Supported Academic Writing: How Can Technology Help?

    ERIC Educational Resources Information Center

    Chitez, Madalina; Rapp, Christian; Kruse, Otto

    2015-01-01

    Phraseology has long been used in L2 teaching of academic writing, and corpus linguistics has played a major role in the compilation and assessment of academic phrases. However, there are only a few interactive academic writing tools in which corpus methodology is implemented in a real-time design to support formulation processes. In this paper,…

  1. Cadec: A corpus of adverse drug event annotations.

    PubMed

    Karimi, Sarvnaz; Metke-Jimenez, Alejandro; Kemp, Madonna; Wang, Chen

    2015-06-01

    CSIRO Adverse Drug Event Corpus (Cadec) is a new rich annotated corpus of medical forum posts on patient-reported Adverse Drug Events (ADEs). The corpus is sourced from posts on social media, and contains text that is largely written in colloquial language and often deviates from formal English grammar and punctuation rules. Annotations contain mentions of concepts such as drugs, adverse effects, symptoms, and diseases linked to their corresponding concepts in controlled vocabularies, i.e., SNOMED Clinical Terms and MedDRA. The quality of the annotations is ensured by annotation guidelines, multi-stage annotations, measuring inter-annotator agreement, and final review of the annotations by a clinical terminologist. This corpus is useful for studies in the area of information extraction, or more generally text mining, from social media to detect possible adverse drug reactions from direct patient reports. The corpus is publicly available at https://data.csiro.au.(1).

  2. Insights from a Learner Corpus as Opposed to a Native Corpus about Cohesive Devices in an Academic Writing Context

    ERIC Educational Resources Information Center

    Ersanli, Ceylan Yangin

    2015-01-01

    This study reports on the insights from an EFL learner corpora (a total of 151 essays and 49,690 words) generated from essays collected over the years in a Turkish state university from freshmen students enrolling in the Advanced Writing course. The comparison of cohesive devices in the non-native corpus (NNC) with those in a native corpus (NC)…

  3. 77 FR 34034 - Corpus Christi Liquefaction, LLC; Cheniere Corpus Christi Pipeline, L.P.; Notice of Intent To...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-08

    ....; Notice of Intent To Prepare an Environmental Assessment for the Planned Corpus Christi LNG Terminal and... assessment (EA) that will discuss the environmental impacts of the planned Corpus Christi LNG Terminal and... (LNG) export and import terminal, and a natural gas transmission pipeline in Nueces and San...

  4. Sweating - absent

    MedlinePlus

    ... diseases or scarring of the skin that block sweat glands Trauma to sweat glands Use of certain drugs Home Care If there ... Miller JL. Diseases of the eccrine and apocrine sweat glands. In: Bolognia JL, Jorizzo JL, Schaffer JV, eds. ...

  5. Thirst - absent

    MedlinePlus

    ... to drink fluids, even when the body is low on water or has too much salt. ... do a detailed nervous system exam if a head injury or problem ... are dehydrated, fluids will likely be given through a vein (IV).

  6. Corpus Linguistics and the Design of a Response Message

    NASA Astrophysics Data System (ADS)

    Atwell, E.

    2002-01-01

    Most research related to SETI, the Search for Extra-Terrestrial Intelligence, is focussed on techniques for detection of possible incoming signals from extra-terrestrial intelligent sources (e.g. Turnbull et al. 1999), and algorithms for analysis of these signals to identify intelligent language-like characteristics (e.g. Elliott and Atwell 1999, 2000). However, another issue for research and debate is the nature of our response, should a signal arrive and be detected. The design of potentially the most significant communicative act in history should not be decided solely by astrophysicists; the Corpus Linguistics research community has a contribution to make to what is essentially a Corpus design and implementation project. (Vakoch 1998) advocated that the message constructed to transmit to extraterrestrials should include a broad, representative collection of perspectives rather than a single viewpoint or genre; this should strike a chord with Corpus Linguists for whom a central principle is that a corpus must be "balanced" to be representative (Meyer 2001). One idea favoured by SETI researchers is to transmit an encyclopaedia summarising human knowledge, such as the Encyclopaedia Britannica, to give ET communicators an overview and "training set" key to analysis of subsequent messages. Furthermore, this should be sent in several versions in parallel: the text; page-images, to include illustrations left out of the text-file and perhaps some sort of abstract linguistic representation of the text, using a functional or logic language (Ollongren 1999, Freudenthal 1960). The idea of "enriching" the message corpus with annotations at several levels should also strike a chord with Corpus Linguists who have long known that Natural language exhibits highly complex multi-layering sequencing, structural and functional patterns, as difficult to model as sequences and structures found in more traditional physical and biological sciences. Some corpora have been annotated with

  7. The tolerance of feline corpus and cauda spermatozoa to cryostress.

    PubMed

    Kunkitti, Panisara; Bergqvist, Ann-Sofi; Sjunnesson, Ylva; Johannisson, Anders; Axnér, Eva

    2016-02-01

    Epididymal sperm preservation can be used to avoid the total loss of genetic material in threatened species. Spermatozoa from the corpus, as from the cauda, are motile and can undergo capacitation. Thus, they can potentially be preserved for assisted reproductive technologies. However, cryopreservation of spermatozoa has a direct detrimental effect on sperm quality. The aim of this study was to compare the chromatin stability and the survival rate of spermatozoa from the corpus and cauda epididymis after cryopreservation. Epididymal spermatozoa were collected and cryopreserved from the corpus and cauda of 12 domestic cats. Sperm motility, progressive motility, membrane integrity, acrosome integrity, and DNA integrity were evaluated before and after freezing thawing. The average total number of spermatozoa collected from the corpus was lower (10.2 × 10(6) ± 7.4) than that from the cauda epididymis (24.9 × 10(6) ± 14.4; P = 0.005). The percentage of spermatozoa with intact DNA did not differ significantly whether it was collected from the corpus or cauda regions and did not decrease after freezing thawing in either region. However, motility of spermatozoa from both regions was affected by the freezing thawing process with a significant decline in motility after thaw compared with fresh spermatozoa. A significant difference in the percentage of motile sperm between the corpus and cauda was observed after the freezing thawing process (P < 0.001). Although sperm motility was lower in postthaw spermatozoa from the corpus epididymidis than from the cauda, the rate of the reduction did not differ between regions. This study indicates that the cryopreservation process does not have a negative effect on chromatin stability of feline epididymal spermatozoa. Spermatozoa from the corpus region have a similar freezability as spermatozoa from the cauda region. Therefore, preservation of spermatozoa from the corpus and the cauda epididymidis might be of value in preserving

  8. A corpus-linguistic investigation of dental English.

    PubMed

    Carlson, D M

    2000-04-01

    This article begins by presenting corpus linguistics and explaining how the corpus approach to language analysis can be used to investigate the language of dentistry. It then reports findings from an analysis that was carried out with readily available software and a corpus of 1,400 dental research abstracts. Included is information about word frequency in dental abstracts and also about how certain words tend to co-occur in sentences and form regular patterns. The article concludes with a discussion of ways that corpus-based findings can be applied to the teaching of English to non-native speakers of the language, many of whom will need English skills for their future careers in dentistry.

  9. RadNet Air Data From Corpus Christi, TX

    EPA Pesticide Factsheets

    This page presents radiation air monitoring and air filter analysis data for Corpus Christi, TX from EPA's RadNet system. RadNet is a nationwide network of monitoring stations that measure radiation in air, drinking water and precipitation.

  10. A massively parallel corpus: the Bible in 100 languages.

    PubMed

    Christodouloupoulos, Christos; Steedman, Mark

    We describe the creation of a massively parallel corpus based on 100 translations of the Bible. We discuss some of the difficulties in acquiring and processing the raw material as well as the potential of the Bible as a corpus for natural language processing. Finally we present a statistical analysis of the corpora collected and a detailed comparison between the English translation and other English corpora.

  11. Building a Large Annotated Corpus of English: The Penn Treebank

    DTIC Science & Technology

    1993-04-30

    Brill 1991]) or the skeletally parsed corpus ([Weischedel et al 1991], [Pereira and Schabes 1992]). The POS-tagged corpus has also been used to train a...Niv 1991] Niv, Michael, 1991. Syntactic disambiguation. In The Penn Review of Linguistics 14, pages 120-126. [Pereira and Schabes 1992] Pereira...Fernando and Schabes , Yves. 1992. Inside-outside reestimation from partially bracketed corpora. In Proceedings of the 30th Annual Meeting of the

  12. Subluxation and semantics: a corpus linguistics study

    PubMed Central

    Budgell, Brian

    2016-01-01

    Introduction: The purpose of this study was to analyze the curriculum of one chiropractic college in order to discover if there were any implicit consensus definitions of the term subluxation. Methods: Using the software WordSmith Tools, the corpus of an undergraduate chiropractic curriculum was analyzed by reviewing collocated terms and through discourse analysis of text blocks containing words based on the root ‘sublux.’ Results: It was possible to identify 3 distinct concepts which were each referred to as ‘subluxation:’ i) an acute or instantaneous injurious event; ii) a clinical syndrome which manifested post-injury; iii) a physical lesion, i.e. an anatomical or physiological derangement which in most instances acted as a pain generator. Conclusions: In fact, coherent implicit definitions of subluxation exist and may enjoy broad but subconscious acceptance. However, confusion likely arises from failure to distinguish which concept an author or speaker is referring to when they employ the term subluxation. PMID:27385839

  13. Paediatric Virology in the Hippocratic Corpus

    PubMed Central

    Mammas, Ioannis N.; Spandidos, Demetrios A.

    2016-01-01

    Hippocrates (Island of Kos, 460 B.C.-Larissa, 370 B.C.) is the founder of the most famous Medical School of the classical antiquity. In acknowledgement of his pioneering contribution to the new scientific field of Paediatric Virology, this article provides a systematic analysis of the Hippocratic Corpus, with particular focus on viral infections predominating in neonates and children. A mumps epidemic, affecting the island of Thasos in the 5th century B.C., is described in detail. ‘Herpes’, a medical term derived from the ancient Greek word ‘ἕρπειν’, meaning ‘to creep’ or ‘crawl’, is used to describe the spreading of cutaneous lesions in both childhood and adulthood. Cases of children with exanthema ‘resembling mosquito bites’ are presented in reference to varicella or smallpox infection. A variety of upper and lower respiratory tract viral infections are described with impressive accuracy, including rhinitis, pharyngitis, tonsillitis, laryngitis, bronchiolitis and bronchitis. The ‘cough of Perinthos’ epidemic, an influenza-like outbreak in the 5th century B.C., is also recorded and several cases complicated with pneumonia or fatal outcomes are discussed. Hippocrates, moreover, describes conjunctivitis, otitis, lymphadenitis, meningoencephalitis, febrile convulsions, gastroenteritis, hepatitis, poliomyelitis and skin warts, along with proposed treatment directions. Almost 2,400 years later, Hippocrates' systematic approach and methodical innovations can inspire paediatric trainees and future Paediatric Virology subspecialists. PMID:27446241

  14. A Corpus Investigation of Syntactic Embedding in Pirahã

    PubMed Central

    Futrell, Richard; Stearns, Laura; Everett, Daniel L.

    2016-01-01

    The Pirahã language has been at the center of recent debates in linguistics, in large part because it is claimed not to exhibit recursion, a purported universal of human language. Here, we present an analysis of a novel corpus of natural Pirahã speech that was originally collected by Dan Everett and Steve Sheldon. We make the corpus freely available for further research. In the corpus, Pirahã sentences have been shallowly parsed and given morpheme-aligned English translations. We use the corpus to investigate the formal complexity of Pirahã syntax by searching for evidence of syntactic embedding. In particular, we search for sentences which could be analyzed as containing center-embedding, sentential complements, adverbials, complementizers, embedded possessors, conjunction or disjunction. We do not find unambiguous evidence for recursive embedding of sentences or noun phrases in the corpus. We find that the corpus is plausibly consistent with an analysis of Pirahã as a regular language, although this is not the only plausible analysis. PMID:26934636

  15. Contrast radiographic study of venous drainage of the corpus cavernosum and the corpus spongiosum of the cat penis.

    PubMed

    Amiri, Ali Akbar; Gilanpour, Hassan; Veshkini, Abbas

    2014-01-01

    The aim of this study was to determine the drainage routes of the corpus cvernosum penis and the corpus spongiosum penis in the cat using contrast cavernosography. Five male cats, 1.5-2.5 years old, weighing between 4.5 and 5.5 kg were investigated. The cats were anesthetized and the root and the proximal part of the penis were exposed by an incision on the perineum reaching the scrotum. Each cat was radiographed in lateral and dorsal recumbency before and during injection of contrast medium into the erectile bodies. The corpus spongiosum penis was injected at the bulb of the penis and the corpus cavernosum penis at the root. Injection of contrast media into the cavernous bodies showed that both the external and internal iliac veins drain the erectile bodies into the caudal vena cava. Drainage from the corpus spongiosum penis was from the bulb for the proximal part and from the glans for the distal part. The corpus cavernosum penis was drained only proximally, from the crura. There was a network of veins above the pelvic symphysis and the drainage of erectile bodies where through various routes into the internal and external iliac veins.

  16. Human corpus luteum secretion of relaxin, oxytocin, and progesterone.

    PubMed

    Khan-Dawood, F S; Goldsmith, L T; Weiss, G; Dawood, M Y

    1989-03-01

    To determine whether the human corpus luteum is a source of relaxin and oxytocin, we measured the concentrations of these peptides in plasma obtained from the ovarian veins of ovaries with and without a corpus luteum and compared these to peripheral plasma levels. Peripheral and ovarian venous blood samples were obtained from 34 nonpregnant women, 13 during the luteal phase and 21 during the follicular phase of their cycles, and from a 6-week pregnant woman. Plasma relaxin, oxytocin, and progesterone concentrations were determined by sensitive and specific RIAs. Plasma relaxin levels were not detectable (less than 0.16 microgram/L) in peripheral or ovarian venous plasma not draining a corpus luteum. The mean relaxin concentration in plasma draining an ovary with a corpus luteum was 0.41 +/- 0.09 (+/- SE) microgram/L. Oxytocin levels also were significantly higher in plasma draining an ovary with a corpus luteum (6.70 +/- 1.86 pmol/L) than in that draining the ovary with no corpus luteum (1.58 +/- 0.09 pmol/L; P less than 0.01) or in peripheral plasma (1.58 +/- 0.09 pmol/L; P less than 0.025). The mean progesterone concentration also was highest in plasma draining an ovary with a corpus luteum (210.2 +/- 50.5 nmol/L) compared with those in plasma from the contralateral ovarian vein (40.3 +/- 16.5 nmol/L P less than 0.005) and peripheral plasma (30.2 +/- 5.7 nmol/L; P less than 0.005) during the luteal phase. In a woman who was 6 weeks pregnant, plasma draining the ovary with a corpus luteum had 1.9 micrograms relaxin/L, but only 0.49 pmol/L oxytocin; the latter was similar to concentrations in noncorpus luteum-bearing ovarian venous plasma. These findings indicate that the human corpus luteum secretes relaxin, oxytocin, and progesterone. Both ovarian oxytocin and relaxin may function as paracrine or autocrine modulators of luteal function.

  17. Transmutation Theory in the Greek Alchemical Corpus.

    PubMed

    Dufault, Olivier

    2015-08-01

    This paper studies transmutation theory as found in the texts attributed to Zosimus of Panopolis, "the philosopher Synesius," and "the philosopher Olympiodorus of Alexandria." It shows that transmutation theory (i.e. a theory explaining the complete transformation of substances) is mostly absent from the work attributed to these three authors. The text attributed to Synesius describes a gilding process, which is similar to those described by Pliny and Vitruvius. The commentary attributed to Olympiodorus is the only text studied here that describes something similar to a transmutation theory. It is unclear, however, if this was a theory of transmutation or if the writer meant something more like the literal meaning of the word "ekstrophē," a term used to describe the transformation of metals, as the "turning inside-out" of what is hidden in a substance. A similar conception of ekstrophē can be found in the works of Zosimus, who discussed transmutation to make an analogy with self-purification processes, which, from the perspective of his own anthropogony, consisted in the "turning inside-out" of the "inner human" (esō anthrōpos).

  18. Case Study: The Perception of Online Tutorials--Habitually Absent Students with Familial or Socioeconomic Circumstances

    ERIC Educational Resources Information Center

    Hudson, Glyniss A.

    2013-01-01

    This case study explored the perception of online tutorials by habitually absent students with familial or socioeconomic circumstances. Researched literature confirmed a link between absenteeism, and academic achievement. Research Questions were designed to determine (a) student perception of online tutorials, and (b) motivation to achieve…

  19. Eyeless initiates the expression of both sine oculis and eyes absent during Drosophila compound eye development.

    PubMed

    Halder, G; Callaerts, P; Flister, S; Walldorf, U; Kloter, U; Gehring, W J

    1998-06-01

    The Drosophila Pax-6 gene eyeless acts high up in the genetic hierarchy involved in compound eye development and can direct the formation of extra eyes in ectopic locations. Here we identify sine oculis and eyes absent as two mediators of the eye-inducing activity of eyeless. We show that eyeless induces and requires the expression of both genes independently during extra eye development. During normal eye development, eyeless is expressed earlier than and is required for the expression of sine oculis and eyes absent, but not vice versa. Based on the results presented here and those of others, we propose a model in which eyeless induces the initial expression of both sine oculis and eyes absent in the eye disc. sine oculis and eyes absent then appear to participate in a positive feedback loop that regulates the expression of all three genes. In contrast to the regulatory interactions that occur in the developing eye disc, we also show that in the embryonic head, sine oculis acts in parallel to eyeless and twin of eyeless, a second Pax-6 gene from Drosophila. Recent studies in vertebrate systems indicate that the epistatic relationships among the corresponding vertebrate homologs are very similar to those observed in Drosophila.

  20. When Familiar Is Not Better: 12-Month-Old Infants Respond to Talk about Absent Objects

    ERIC Educational Resources Information Center

    Osina, Maria A.; Saylor, Megan M.; Ganea, Patricia A.

    2013-01-01

    Three experiments that demonstrate a novel constraint on infants' language skills are described. Across the experiments it is shown that as babies near their 1st birthday, their ability to respond to talk about an absent object is influenced by a referent's spatiotemporal history: familiarizing infants with an object in 1 or several nontest…

  1. Reconstruction of a congenitally absent flexor pollicis longus in an adult

    PubMed Central

    Shamsian, Negin; Exton, Rebecca; Shibu, MM

    2010-01-01

    Congenital absence of the flexor pollicis longus (FPL) is an unusual finding that is frequently associated with thumb hypoplasia. Isolated FPL absence is the rarest of the congenital thumb anomalies. The present article describes a patient with a congenitally absent FPL, and discusses the chosen method of reconstruction. PMID:22131842

  2. Discourse and identity in a corpus of lesbian erotica.

    PubMed

    Morrish, Liz; Sauntson, Helen

    2011-01-01

    This article uses corpus linguistic methodologies to explore representations of lesbian desires and identities in a corpus of lesbian erotica from the 1980s and 1990s. We provide a critical examination of the ways in which "lesbian gender," power, and desire are represented, (re-)produced, and enacted, often in ways that challenge hegemonic discourses of gender and sexuality. By examining word frequencies and collocations, we critically analyze some of the themes, processes, and patterns of representation in the texts. Although rooted in linguistics, we hope this article provides an accessible, interdisciplinary, and timely contribution toward developing understandings of discursive practices surrounding gender and sexuality.

  3. A multimodal corpus of speech to infant and adult listeners.

    PubMed

    Johnson, Elizabeth K; Lahey, Mybeth; Ernestus, Mirjam; Cutler, Anne

    2013-12-01

    An audio and video corpus of speech addressed to 28 11-month-olds is described. The corpus allows comparisons between adult speech directed toward infants, familiar adults, and unfamiliar adult addressees as well as of caregivers' word teaching strategies across word classes. Summary data show that infant-directed speech differed more from speech to unfamiliar than familiar adults, that word teaching strategies for nominals versus verbs and adjectives differed, that mothers mostly addressed infants with multi-word utterances, and that infants' vocabulary size was unrelated to speech rate, but correlated positively with predominance of continuous caregiver speech (not of isolated words) in the input.

  4. Mayer Rokitansky Kuster Hauser (MRKH) syndrome with absent thumbs and big toes.

    PubMed

    Yunus, Mahira

    2014-01-01

    Mayer-Rokitansky-Kuster-Hauser (MRKH) syndrome is a rare developmental failure of Müllerian ducts. Principle clinical features of MRKH syndrome are primary amenorrhoea associated with congenital absence of vagina, uterine anomalies, normal ovaries, 46 XX karyotype with normal female secondary sexual characteristics and frequent association with renal, skeletal, and other congenital anomalies. A case of a 3-year-old child with congenitally absent thumbs and big toes is reported herein; she was brought in with complaints of urinary incontinence. Radiological investigation (ultrasound and magnetic resonance imaging (MRI) scan) revealed absent uterus and vagina while both ovaries were normal. Intravenous urography (IVU) study showed bifid pelvicalyceal systems bilaterally. Karyotyping revealed a 46 XX female phenotype. Laparoscopy confirmed normal ovaries bilaterally and small unfused uterine buds lying beside both ovaries on each side of pelvis. Early diagnosis of MRKH syndrome is essential for timely planning of vaginal and (if possible) uterine reconstructive surgeries.

  5. A surviving infant with sirenomelia (Mermaid syndrome) associated with absent bladder.

    PubMed

    Stanton, Michael P; Penington, Elizabeth C; Hutson, John M

    2003-08-01

    The authors report a case of a surviving infant with sirenomelia (Mermaid syndrome). The child is now 4 years of age. The authors believe that this is only the fourth reported case of an infant with sirenomelia surviving beyond the neonatal period and the first associated with absent bladder. The abnormal distal aorta shown in this case supports the theory that sirenomelia is an extreme form of caudal dysgenesis rather than occurring secondary to vascular steal.

  6. Surgical treatment of tetralogy of Fallot with absent pulmonary valve syndrome.

    PubMed

    Tanaka, Yuki; Miyamoto, Takashi; Naito, Yuji; Yoshitake, Shuichi

    2016-06-01

    The patient was a 3-month-old girl weighting 3.6 kg, diagnosed with tetralogy of Fallot and absent pulmonary valve syndrome. We surgically repaired the tetralogy of Fallot by patch closure of the ventricular septal defect, right ventricular outflow tract reconstruction using an expanded polytetrafluoroethylene monocusp patch with a bulging sinus, and removal of the bronchial obstruction by anterior translocation of the pulmonary artery using the Lecompte maneuver.

  7. The bulk and the tail of minimal absent words in genome sequences

    NASA Astrophysics Data System (ADS)

    Aurell, Erik; Innocenti, Nicolas; Zhou, Hai-Jun

    2016-04-01

    Minimal absent words (MAW) of a genomic sequence are subsequences that are absent themselves but the subwords of which are all present in the sequence. The characteristic distribution of genomic MAWs as a function of their length has been observed to be qualitatively similar for all living organisms, the bulk being rather short, and only relatively few being long. It has been an open issue whether the reason behind this phenomenon is statistical or reflects a biological mechanism, and what biological information is contained in absent words. In this work we demonstrate that the bulk can be described by a probabilistic model of sampling words from random sequences, while the tail of long MAWs is of biological origin. We introduce the concept of a core of a MAW, which are sequences present in the genome and closest to a given MAW. We show that in E. faecalis, E. coli and yeast the cores of the longest MAWs, which exist in two or more copies, are located in highly conserved regions the most prominent example being ribosomal RNAs. We also show that while the distribution of the cores of long MAWs is roughly uniform over these genomes on a coarse-grained level, on a more detailed level it is strongly enhanced in 3’ untranslated regions (UTRs) and, to a lesser extent, also in 5’ UTRs. This indicates that MAWs and associated MAW cores correspond to fine-tuned evolutionary relationships, and suggest that they can be more widely used as markers for genomic complexity.

  8. Gender-based violence and absent fathers: a scoping review protocol

    PubMed Central

    Sikweyiya, Yandisa; Nduna, Mzikazi; Khuzwayo, Nelisiwe; Mthombeni, Andile; Mashamba-Thompson, Tivani Phosa

    2016-01-01

    Introduction Gender-based violence (GBV) and absent fathers are two epidemics that affect women and children in sub-Saharan Africa. However, the understanding of the complex links between GBV and absent fathers is currently inadequate. The aim of the study is to provide an overview of documented evidence that links GBV and absent fathers as well as identifies areas that require systematic review and where more primary research is needed. Methods and analysis The search strategy for this scoping review study will involve electronic databases including: Academic Search Premier, Ingenta, Kluwer Online, PsycARTICLES (EBSCO), PsycINFO (EBSCO), Social Work Abstracts and Sociological Collection. The studies will be mapped in 2 stages: stage 1 will map studies descriptively by focus and method; stage 2 will involve additional inclusion criteria, quality assessment and data extraction undertaken by two reviewers in parallel. A thematic analysis of the studies will be carried out to extract relevant outcomes using NVIVO. Discussion We anticipate finding a large number of studies on GBV diagnostic interventions in sub-Saharan Africa which, once summarised, will be useful to guide future research. The protocol for the scoping review has been registered in PROSPERO. Dissemination The study will be disseminated electronically and in print. It will also be presented to conferences related to GBV, Father Connections and Children's Health. PROSPERO registration number CRD42015022094. PMID:27297007

  9. Cardiac-locked bursts of muscle sympathetic nerve activity are absent in familial dysautonomia

    PubMed Central

    Macefield, Vaughan G; Norcliffe-Kaufmann, Lucy; Axelrod, Felicia B; Kaufmann, Horacio

    2013-01-01

    Familial dysautonomia (Riley–Day syndrome) is an hereditary sensory and autonomic neuropathy (HSAN type III), expressed at birth, that is associated with reduced pain and temperature sensibilities and absent baroreflexes, causing orthostatic hypotension as well as labile blood pressure that increases markedly during emotional excitement. Given the apparent absence of functional baroreceptor afferents, we tested the hypothesis that the normal cardiac-locked bursts of muscle sympathetic nerve activity (MSNA) are absent in patients with familial dysautonomia. Tungsten microelectrodes were inserted percutaneously into muscle or cutaneous fascicles of the common peroneal nerve in 12 patients with familial dysautonomia. Spontaneous bursts of MSNA were absent in all patients, but in five patients we found evidence of tonically firing sympathetic neurones, with no cardiac rhythmicity, that increased their spontaneous discharge during emotional arousal but not during a manoeuvre that unloads the baroreceptors. Conversely, skin sympathetic nerve activity (SSNA), recorded in four patients, appeared normal. We conclude that the loss of phasic bursts of MSNA and the loss of baroreflex modulation of muscle vasoconstrictor drive contributes to the poor control of blood pressure in familial dysautonomia, and that the increase in tonic firing of muscle vasoconstrictor neurones contributes to the increase in blood pressure during emotional excitement. PMID:23165765

  10. Pharmacological characterization of adrenoceptors in horse corpus cavernosum penis.

    PubMed

    Recio, P; López, P G; Fernández, J L; Garcia-Sacristán, A

    1997-06-01

    1. The presence and types of alpha and beta-adrenoceptors in the corpus cavernosum of the horse were studied in vitro by using selected ligands of adrenoceptors and isometric tension recording. 2. Noradrenaline and phenylephrine induced concentration-dependent contractions in corpus cavernosum preparations. B-HT 920 had no effect. 3. Phentolamine and prazosin produced a shift to the right of the dose-response curve of noradrenaline, while the alpha(2)-antagonist, rauwolscine had no effect on the response to noradrenaline. Phenylephrine-evoked contractions of corporal strips were significantly inhibited by the alpha(1)-adrenoceptor antagonist, prazosin. 4. Isoprenaline and salbutamol each relaxed precontracted corpus cavernosum preparations in a concentration-dependent manner; the isoprenaline effect was blocked by propranolol, practolol and butoxamine. The salbutamol effect was blocked by butoxamine. 5. These results suggest that presence of postjunctional alpha(1)-adrenoceptors in horse corpus cavernosum. There is also a heterogenous population of beta-adrenoceptors in this tissue, belonging to the beta(1) and beta(2) subtypes.

  11. Corpus-Based Learning of Cantonese for Mandarin Speakers

    ERIC Educational Resources Information Center

    Wong, Tak-Sum; Lee, John S. Y.

    2016-01-01

    This article presents the first study on using a parallel corpus to teach Cantonese, the variety of Chinese spoken in Hong Kong. We evaluated this approach with Mandarin-speaking undergraduate students at the beginner level. Exploiting their knowledge of Mandarin, a closely related language, the students studied Cantonese with authentic material…

  12. Corpus Linguistics, Network Analysis and Co-Occurrence Matrices

    ERIC Educational Resources Information Center

    Stuart, Keith; Botella, Ana

    2009-01-01

    This article describes research undertaken in order to design a methodology for the reticular representation of knowledge of a specific discourse community. To achieve this goal, a representative corpus of the scientific production of the members of this discourse community (Universidad Politecnica de Valencia, UPV) was created. This article…

  13. You Should Have the Body: Understanding Habeas Corpus

    ERIC Educational Resources Information Center

    Landman, James

    2008-01-01

    English legal commentator William Blackstone described the writ of habeas corpus as a second Magna Carta, and Supreme Court Chief Justice John Marshall called it the "great writ." It has been part of the Anglo-American common law tradition since the Middle Ages. In the United States, it has been a source of tension between state and…

  14. Modifying Corpus Annotation to Support the Analysis of Learner Language

    ERIC Educational Resources Information Center

    Dickinson, Markus; Lee, Chong Min

    2009-01-01

    A crucial question for automatically analyzing learner language is to determine which grammatical information is relevant and useful for learner feedback. Based on knowledge about how learner language varies in its grammatical properties, we propose a framework for reusing analyses found in corpus annotation and illustrate its applicability to…

  15. A Corpus-Based Comparative Study of "Learn" and "Acquire"

    ERIC Educational Resources Information Center

    Yang, Bei

    2016-01-01

    As an important yet intricate linguistic feature in English language, synonymy poses a great challenge for second language learners. Using the 100 million-word British National Corpus (BNC) as data and the software Sketch Engine (SkE) as an analyzing tool, this article compares the usage of "learn" and "acquire" used in natural…

  16. Corpus Planning for the Southern Peruvian Quechua Language.

    ERIC Educational Resources Information Center

    Coronel-Molina, Serafin M.

    1997-01-01

    The discussion of corpus planning for the Southern Quechua language variety of Peru examines issues of graphization, standardization, modernization, and renovation of Quechua in the face of increasing domination by the Spanish language. The efforts of three major groups of linguists and other scholars working on language planning in Peru, and the…

  17. Combining text clustering and retrieval for corpus adaptation

    NASA Astrophysics Data System (ADS)

    He, Feng; Ding, Xiaoqing

    2007-01-01

    The application-relevant text data are very useful in various natural language applications. Using them can achieve significantly better performance for vocabulary selection, language modeling, which are widely employed in automatic speech recognition, intelligent input method etc. In some situations, however, the relevant data is hard to collect. Thus, the scarcity of application-relevant training text brings difficulty upon these natural language processing. In this paper, only using a small set of application specific text, by combining unsupervised text clustering and text retrieval techniques, the proposed approach can find the relevant text from unorganized large scale corpus, thereby, adapt training corpus towards the application area of interest. We use the performance of n-gram statistical language model, which is trained from the text retrieved and test on the application-specific text, to evaluate the relevance of the text acquired, accordingly, to validate the effectiveness of our corpus adaptation approach. The language models trained from the ranked text bundles present well discriminated perplexities on the application-specific text. The preliminary experiments on short message text and unorganized large corpus demonstrate the performance of the proposed methods.

  18. A Multidimensional Analysis of a Written L2 Spanish Corpus

    ERIC Educational Resources Information Center

    Asencion-Delaney, Yuly; Collentine, Joseph

    2011-01-01

    The present study adds to our understanding of how learners employ lexical and grammatical phenomena to communicate in writing in different types of interlanguage discourse. A multidimensional (factor) analysis of a corpus of L2 Spanish writing (202,241 words) generated by second- and third-year, university-level learners was performed. The…

  19. Dative Alternation in Indian English: A Corpus-Based Analysis

    ERIC Educational Resources Information Center

    De Cuypere, Ludovic; Verbeke, Saartje

    2013-01-01

    The dative alternation refers to the alternation between two constructions that denote some type of transfer: the double object construction ("I give my sister a book") vs. the to-dative construction ("I give a book to my sister"). We examined the motivations behind the dative alternation in Indian English. A corpus study was…

  20. Learner Corpus Analysis and the Development of Foreign Language Proficiency

    ERIC Educational Resources Information Center

    Belz, Julie A.

    2004-01-01

    This paper makes a methodological contribution to the emerging field of learner corpus analysis [Granger, S., 1998. Learner English on Computer. Longman, London, 1998; Granger, S., 2002. Computer Learner corpora, Second Language Acquisition, and Foreign Language Teaching. John Benjamins, Amsterdam, 2002] and to Second Language Acquisition (SLA)…

  1. 38 CFR 3.263 - Corpus of estate; net worth.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2011-07-01 2011-07-01 false Corpus of estate; net worth. 3.263 Section 3.263 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS ADJUDICATION Pension, Compensation, and Dependency and Indemnity Compensation Dependency, Income and Estate §...

  2. 38 CFR 3.263 - Corpus of estate; net worth.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2014-07-01 2014-07-01 false Corpus of estate; net worth. 3.263 Section 3.263 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS ADJUDICATION Pension, Compensation, and Dependency and Indemnity Compensation Dependency, Income and Estate §...

  3. 38 CFR 3.263 - Corpus of estate; net worth.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2012-07-01 2012-07-01 false Corpus of estate; net worth. 3.263 Section 3.263 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS ADJUDICATION Pension, Compensation, and Dependency and Indemnity Compensation Dependency, Income and Estate §...

  4. An integrated pharmacokinetics ontology and corpus for text mining

    PubMed Central

    2013-01-01

    Background Drug pharmacokinetics parameters, drug interaction parameters, and pharmacogenetics data have been unevenly collected in different databases and published extensively in the literature. Without appropriate pharmacokinetics ontology and a well annotated pharmacokinetics corpus, it will be difficult to develop text mining tools for pharmacokinetics data collection from the literature and pharmacokinetics data integration from multiple databases. Description A comprehensive pharmacokinetics ontology was constructed. It can annotate all aspects of in vitro pharmacokinetics experiments and in vivo pharmacokinetics studies. It covers all drug metabolism and transportation enzymes. Using our pharmacokinetics ontology, a PK-corpus was constructed to present four classes of pharmacokinetics abstracts: in vivo pharmacokinetics studies, in vivo pharmacogenetic studies, in vivo drug interaction studies, and in vitro drug interaction studies. A novel hierarchical three level annotation scheme was proposed and implemented to tag key terms, drug interaction sentences, and drug interaction pairs. The utility of the pharmacokinetics ontology was demonstrated by annotating three pharmacokinetics studies; and the utility of the PK-corpus was demonstrated by a drug interaction extraction text mining analysis. Conclusions The pharmacokinetics ontology annotates both in vitro pharmacokinetics experiments and in vivo pharmacokinetics studies. The PK-corpus is a highly valuable resource for the text mining of pharmacokinetics parameters and drug interactions. PMID:23374886

  5. 38 CFR 3.263 - Corpus of estate; net worth.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... the corpus of estate of a parent where dependency is a factor under § 3.250, and the net worth of a....252(b). Only the estate of the parent, in claims based on dependency, or the estate of the veteran... all real and personal property owned by the claimant except the claimant's dwelling...

  6. The Use of Corpus Examples for Language Comprehension and Production

    ERIC Educational Resources Information Center

    Frankenberg-Garcia, Ana

    2014-01-01

    One of the many new features of English language learners' dictionaries derived from the technological developments that have taken place over recent decades is the presence of corpus-based examples to illustrate the use of words in context. However, empirical studies have generally not been able to produce conclusive evidence about their…

  7. Semantic Associations in Business English: A Corpus-Based Analysis

    ERIC Educational Resources Information Center

    Nelson, Mike

    2006-01-01

    This paper examines the semantic associations of words found in the business lexical environment by using a one-million word corpus of both spoken and written Business English. The key method of analysis is that of semantic prosody or semantic association; the notion that words associate with collocates that are themselves related, often either…

  8. The Dependency Structure of Coordinate Phrases: A Corpus Approach

    ERIC Educational Resources Information Center

    Temperley, David

    2005-01-01

    Hudson (1990) proposes that each conjunct in a coordinate phrase forms dependency relations with heads or dependents outside the coordinate phrase (the "multi-head" view). This proposal is tested through corpus analysis of Wall Street Journal text. For right-branching constituents (such as direct-object NPs), a short-long preference for conjunct…

  9. Motivating College Students' Learning English for Specific Purposes Courses through Corpus Building

    ERIC Educational Resources Information Center

    Wu, Lin-Fang

    2014-01-01

    This study was conducted to determine how to motivate technical college students to learn English for specific purposes (ESP) courses through corpus building and enhance their language proficiency during the coursework for their majors. This study explores corpus building skills, how to simplify ESP courses by corpus building for English as second…

  10. Evaluating Corpus Literacy Training for Pre-Service Language Teachers: Six Case Studies

    ERIC Educational Resources Information Center

    Heather, Julian; Helt, Marie

    2012-01-01

    Corpus literacy is the ability to use corpora--large, principled databases of spoken and written language--for language analysis and instruction. While linguists have emphasized the importance of corpus training in teacher preparation programs, few studies have investigated the process of initiating teachers into corpus literacy with the result…

  11. 26 CFR 1.661(a)-1 - Estates and trusts accumulating income or distributing corpus; general.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... distributing corpus; general. 1.661(a)-1 Section 1.661(a)-1 Internal Revenue INTERNAL REVENUE SERVICE... Accumulate Income Or Which Distribute Corpus § 1.661(a)-1 Estates and trusts accumulating income or distributing corpus; general. Subpart C, part I, subchapter J, chapter 1 of the Code, is applicable to...

  12. Corpus-Based Research and Pedagogy in EAP: From Lexis to Genre

    ERIC Educational Resources Information Center

    Flowerdew, Lynne

    2015-01-01

    This plenary paper showcases current corpus-based research on written academic English, illustrating the tight links that exist between corpus research and pedagogic applications. I first explicate Sinclair's concept of the "lexical approach", which underpins much corpus research and pedagogy. I then discuss studies which focus on…

  13. 76 FR 31821 - Amendment of Class D Airspace; Corpus Christi, TX

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-02

    ... Federal Aviation Administration 14 CFR Part 71 Amendment of Class D Airspace; Corpus Christi, TX AGENCY... amends Class D airspace within the Corpus Christi, TX, area by updating the geographic coordinates for... the geographic coordinates, within Class D airspace, of the Cabaniss NOLF, Corpus Christi, TX,...

  14. 76 FR 49285 - Amendment of Class D Airspace; Corpus Christi, TX

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-10

    ... Federal Aviation Administration 14 CFR Part 71 Amendment of Class D Airspace; Corpus Christi, TX AGENCY... Register June 2, 2011, ] amending Class D airspace at Cabaniss Navy Outlying Field (NOLF), Corpus Christi... Cabaniss NOLF, Corpus Christi, TX (76 FR 31821, Docket No. FAA-2010-1171). Subsequent to publication,...

  15. Separating Fact and Fiction: The Real Story of Corpus Use in Language Teaching

    ERIC Educational Resources Information Center

    Boulton, Alex

    2013-01-01

    This paper investigates uses of corpora in language learning ("data-driven learning") through analysis of a 600K-word corpus of empirical research papers in the field. The corpus can tell us much--the authors and the countries the studies are conducted in, the types of publication, and so on. The corpus investigation itself starts with…

  16. 26 CFR 1.643(b)-2 - Dividends allocated to corpus.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 8 2010-04-01 2010-04-01 false Dividends allocated to corpus. 1.643(b)-2... to corpus. Extraordinary dividends or taxable stock dividends which the fiduciary, acting in good faith, determines to be allocable to corpus under the terms of the governing instrument and...

  17. 40 CFR 81.136 - Corpus Christi-Victoria Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 17 2010-07-01 2010-07-01 false Corpus Christi-Victoria Intrastate Air... Air Quality Control Regions § 81.136 Corpus Christi-Victoria Intrastate Air Quality Control Region. The Corpus Christi-Victoria Intrastate Air Quality Control Region (Texas) consists of the...

  18. The role of GPR1 signaling in mice corpus luteum.

    PubMed

    Yang, Ya-Li; Ren, Li-Rong; Sun, Li-Feng; Huang, Chen; Xiao, Tian-Xia; Wang, Bao-Bei; Chen, Jie; Zabel, Brian A; Ren, Peigen; Zhang, Jian V

    2016-07-01

    Chemerin, a chemokine, plays important roles in immune responses, inflammation, adipogenesis, and carbohydrate metabolism. Our recent research has shown that chemerin has an inhibitory effect on hormone secretion from the testis and ovary. However, whether G protein-coupled receptor 1 (GPR1), the active receptor for chemerin, regulates steroidogenesis and luteolysis in the corpus luteum is still unknown. In this study, we established a pregnant mare serum gonadotropin-human chorionic gonadotropin (PMSG-hCG) superovulation model, a prostaglandin F2α (PGF2α) luteolysis model, and follicle and corpus luteum culture models to analyze the role of chemerin signaling through GPR1 in the synthesis and secretion of gonadal hormones during follicular/luteal development and luteolysis. Our results, for the first time, show that chemerin and GPR1 are both differentially expressed in the ovary over the course of the estrous cycle, with highest levels in estrus and metestrus. GPR1 has been localized to granulosa cells, cumulus cells, and the corpus luteum by immunohistochemistry (IHC). In vitro, we found that chemerin suppresses hCG-induced progesterone production in cultured follicle and corpus luteum and that this effect is attenuated significantly by anti-GPR1 MAB treatment. Furthermore, when the phosphoinositide 3-kinase (PI3K) pathway was blocked, the attenuating effect of GPR1 MAB was abrogated. Interestingly, PGF2α induces luteolysis through activation of caspase-3, leading to a reduction in progesterone secretion. Treatment with GPR1 MAB blocked the PGF2α effect on caspase-3 expression and progesterone secretion. This study indicates that chemerin/GPR1 signaling directly or indirectly regulates progesterone synthesis and secretion during the processes of follicular development, corpus luteum formation, and PGF2α-induced luteolysis.

  19. Using Google as a Super Corpus to Drive Written Language Learning: A Comparison with the British National Corpus

    ERIC Educational Resources Information Center

    Sha, Guoquan

    2010-01-01

    Data-driven learning (DDL), or corpus-based language learning, involves the learner in an exploratory task to discover appropriate expressions or collocates regarding his writing. However, the problematic units of meaning in each learner's writing are so diverse that conventional corpora often prove futile. The search engine Google with the…

  20. Formulaic Language and Collocations in German Essays: From Corpus-Driven Data to Corpus-Based Materials

    ERIC Educational Resources Information Center

    Krummes, Cedric; Ensslin, Astrid

    2015-01-01

    Whereas there exists a plethora of research on collocations and formulaic language in English, this article contributes towards a somewhat less developed area: the understanding and teaching of formulaic language in German as a foreign language. It analyses formulaic sequences and collocations in German writing (corpus-driven) and provides modern…

  1. Anal atresia, abnormal genitalia, and absent thumb: congenital malformations associated with mosaic ring chromosome 13.

    PubMed

    Ocak, Z; Ozlu, T; Vural, M

    2013-01-01

    Because of the deletion of a segment of the chromosome during the formation of a ring, several clinical findings may be associated with ring chromosomes. Ring chromosome 13 is one of such disorders in which the genotype-phenotype correlation is stronger by virtue of the accumulating literature. It can be associated with multiple congenital abnormalities and severe mental retardation. We report a case with mosaic ring chromosome 13 whose prenatal ultrasound revealed bilateral ventriculomegaly. Anal atresia, unidentifiable external genitalia, and an absent thumb were observed in the postmortem examination.

  2. Lateral facial cleft associated with accessory mandible having teeth, absent parotid gland and peripheral facial weakness.

    PubMed

    Ozçelik, D; Toplu, G; Türkseven, A; Senses, D A; Yiğit, B

    2014-07-01

    Transverse facial cleft is a very rare malformation. The Tessier no. 7 cleft is a lateral facial cleft which emanates from oral cavity and extends towards the tragus, involving both soft tissue and skeletal components. Here, we present a case having transverse facial cleft, accessory mandible having teeth, absent parotid gland and ipsilateral peripheral facial nerve weakness. After surgical repair of the cleft in 2-month of age, improvement of the facial nerve function was detected in 3-year of age. Resection of the accessory mandible was planned in 5-6 years of age.

  3. Profuse congenital familial milia with absent dermatoglyphics (Basan's Syndrome): description of a new family.

    PubMed

    Luna, Paula Carolina; Larralde, Margarita

    2012-01-01

    Milia are common, small, keratin-containing cysts frequently seen in all age groups. They may arise spontaneously or develop after a variety of stimuli. They can be found alone or as part of syndromes. We present a female neonate born not only with profuse facial milia, but also with acral bullae and absent dermatoglyphics. Similar features were seen in several members of her family. These findings correspond to the syndrome known as Basan's syndrome, a rare autosomal-dominant inherited dermatosis characterized by profuse congenital milia, transient neonatal acral bullae, and absence of dermatoglyphics.

  4. [Tetralogy of Fallot with absent pulmonary valve in a newborn and infant. Complete surgical correction].

    PubMed

    Cabrera Duro, A; Rodrigo Carbonero, D; Martínez Corrales, P; Aramendi Gallardo, J; Alcíbar Villa, J; López de Heredia Goya, J; Romero Ibarra, C

    2004-02-01

    We report two patients, a newborn and a 7-month old infant, with tetralogy of Fallot and absent pulmonary valve syndrome. Both had severe obstruction at the level of the ring with aneurysmal pulmonary artery branches, which compressed and displaced the trachea and main bronchial tubes. The neonate required mechanical ventilation from birth. Treatment was aggressive in both patients with interventricular septum defect closure, arterioplasty of the branches and homograft in the infant, and resection of the truncus and pulmonary branches with posterior face suture of both branches associated with a valved conduit in orthotopic position in the neonate. We believe that early treatment avoids airway degeneration and right ventricle volume overload.

  5. Group velocity mismatch-absent nonlinear frequency conversions for mid-infrared femtosecond pulses generation

    PubMed Central

    Zhong, Haizhe; Zhang, Lifu; Li, Ying; Fan, Dianyuan

    2015-01-01

    A novel group velocity mismatch (GVM) absent scheme for nonlinear optical parametric procedure in mid-infrared was developed with type-I quasi phase matching by use of an off-digital nonlinear optical coefficient d31. This was achieved by matching of the group velocities of the pump and the signal waves, while the phase velocities were quasi phase matched. The system employs MgO-doped periodically poled LiNbO3 as the nonlinear medium. Desired group-velocity dispersion would be obtained via appropriately temperature regulation. To demonstrate its potential applications in ultrafast mid-infrared pulses generation, aiming at a typical mid-infrared wavelength of ~3.2 μm, design examples of two basic nonlinear frequency conversion procedures are studied for both the narrow-band seeding mid-IR optical parametric amplification (OPA) and the synchronously pumped femtosecond optical parametric oscillation (SPOPO). Compared with the conventional scheme of type-0 QPM, the quantum-efficiency can be more than doubled with nearly unlimited bandwidth. The proposed GVM- absent phase matching design may provide a promising route to efficient and broadband sub-100 fs mid-infrared ultrafast pulses generation without group-velocity walk-off. PMID:26099837

  6. Distractor Dwelling, Skipping, and Revisiting Determine Target Absent Performance in Difficult Visual Search

    PubMed Central

    Horstmann, Gernot; Herwig, Arvid; Becker, Stefanie I.

    2016-01-01

    Some targets in visual search are more difficult to find than others. In particular, a target that is similar to the distractors is more difficult to find than a target that is dissimilar to the distractors. Efficiency differences between easy and difficult searches are manifest not only in target-present trials but also in target-absent trials. In fact, even physically identical displays are searched through with different efficiency depending on the searched-for target. Here, we monitored eye movements in search for a target similar to the distractors (difficult search) versus a target dissimilar to the distractors (easy search). We aimed to examine three hypotheses concerning the causes of differential search efficiencies in target-absent trials: (a) distractor dwelling (b) distractor skipping, and (c) distractor revisiting. Reaction times increased with target similarity which is consistent with existing theories and replicates earlier results. Eye movement data indicated guidance in target trials, even though search was very slow. Dwelling, skipping, and revisiting contributed to low search efficiency in difficult search, with dwelling being the strongest factor. It is argued that differences in dwell time account for a large amount of total search time differences. PMID:27574510

  7. Distractor Dwelling, Skipping, and Revisiting Determine Target Absent Performance in Difficult Visual Search.

    PubMed

    Horstmann, Gernot; Herwig, Arvid; Becker, Stefanie I

    2016-01-01

    Some targets in visual search are more difficult to find than others. In particular, a target that is similar to the distractors is more difficult to find than a target that is dissimilar to the distractors. Efficiency differences between easy and difficult searches are manifest not only in target-present trials but also in target-absent trials. In fact, even physically identical displays are searched through with different efficiency depending on the searched-for target. Here, we monitored eye movements in search for a target similar to the distractors (difficult search) versus a target dissimilar to the distractors (easy search). We aimed to examine three hypotheses concerning the causes of differential search efficiencies in target-absent trials: (a) distractor dwelling (b) distractor skipping, and (c) distractor revisiting. Reaction times increased with target similarity which is consistent with existing theories and replicates earlier results. Eye movement data indicated guidance in target trials, even though search was very slow. Dwelling, skipping, and revisiting contributed to low search efficiency in difficult search, with dwelling being the strongest factor. It is argued that differences in dwell time account for a large amount of total search time differences.

  8. Frequency of Basic English Grammatical Structures: A Corpus Analysis

    PubMed Central

    Roland, Douglas; Dick, Frederic; Elman, Jeffrey L.

    2009-01-01

    Many recent models of language comprehension have stressed the role of distributional frequencies in determining the relative accessibility or ease of processing associated with a particular lexical item or sentence structure. However, there exist relatively few comprehensive analyses of structural frequencies, and little consideration has been given to the appropriateness of using any particular set of corpus frequencies in modeling human language. We provide a comprehensive set of structural frequencies for a variety of written and spoken corpora, focusing on structures that have played a critical role in debates on normal psycholinguistics, aphasia, and child language acquisition, and compare our results with those from several recent papers to illustrate the implications and limitations of using corpus data in psycholinguistic research. PMID:19668599

  9. The absence of corpus luteum formation alters the endocrine profile and affects follicular development during the first follicular wave in cattle.

    PubMed

    Hayashi, Ken-Go; Matsui, Motozumi; Shimizu, Takashi; Sudo, Natsuko; Sato, Ayako; Shirasuna, Koumei; Tetsuka, Masa; Kida, Katsuya; Schams, Dieter; Miyamoto, Akio

    2008-12-01

    We previously established a bovine experimental model showing that the corpus luteum (CL) does not appear following aspiration of the preovulatory follicle before the onset of LH surge. Using this model, the present study aimed to determine the profile of follicular development and the endocrinological environment in the absence of CL with variable nadir circulating progesterone (P(4)) concentrations during the oestrous cycle in cattle. Luteolysis was induced in heifers and cows and they were assigned either to have the dominant follicle aspirated (CL-absent) or ovulation induced (CL-present). Ultrasound scanning to observe the diameter of each follicle and blood collection was performed from the day of follicular aspiration or ovulation and continued for 6 days. The CL-absent cattle maintained nadir circulating P(4) throughout the experimental period and showed a similar diameter between the largest and second largest follicle, resulting in co-dominant follicles. Oestradiol (E(2)) concentrations were greater in the CL-absent cows than in the CL-present cows at day -1, day 1 and day 2 from follicular deviation. The CL-absent cows had a higher basal concentration, area under the curve (AUC), pulse amplitude and pulse frequency of LH than the CL-present cows. After follicular deviation, the CL-absent cows showed a greater basal concentration, AUC and pulse amplitude of growth hormone (GH) than the CL-present cows. These results suggest that the absence of CL accompanying nadir circulating P(4) induces an enhancement of LH pulses, which involves the growth of the co-dominant follicles. Our results also suggest that circulating levels of P(4) and E(2) affect pulsatile GH secretion in cattle.

  10. Anaphoric relations in the clinical narrative: corpus creation

    PubMed Central

    Chapman, Wendy W; Zheng, Jiaping; Crowley, Rebecca S

    2011-01-01

    Objective The long-term goal of this work is the automated discovery of anaphoric relations from the clinical narrative. The creation of a gold standard set from a cross-institutional corpus of clinical notes and high-level characteristics of that gold standard are described. Methods A standard methodology for annotation guideline development, gold standard annotations, and inter-annotator agreement (IAA) was used. Results The gold standard annotations resulted in 7214 markables, 5992 pairs, and 1304 chains. Each report averaged 40 anaphoric markables, 33 pairs, and seven chains. The overall IAA is high on the Mayo dataset (0.6607), and moderate on the University of Pittsburgh Medical Center (UPMC) dataset (0.4072). The IAA between each annotator and the gold standard is high (Mayo: 0.7669, 0.7697, and 0.9021; UPMC: 0.6753 and 0.7138). These results imply a quality corpus feasible for system development. They also suggest the complementary nature of the annotations performed by the experts and the importance of an annotator team with diverse knowledge backgrounds. Limitations Only one of the annotators had the linguistic background necessary for annotation of the linguistic attributes. The overall generalizability of the guidelines will be further strengthened by annotations of data from additional sites. This will increase the overall corpus size and the representation of each relation type. Conclusion The first step toward the development of an anaphoric relation resolver as part of a comprehensive natural language processing system geared specifically for the clinical narrative in the electronic medical record is described. The deidentified annotated corpus will be available to researchers. PMID:21459927

  11. Localization of relaxin in human gestational corpus luteum.

    PubMed

    Mathieu, P; Rahier, J; Thomas, K

    1981-01-01

    Corpora lutea from 12 pregnant women were prepared for immunohistochemical localization of relaxin using a highly specific antiserum. A positive response is given by luteal cells that are diffusely distributed throughout the corpus luteum. These cells do not form a distinctive group in any particular area. A negative response is seen in the adjacent ovarian tissue, and also in nongestational corpora lutea in early luteal phase.

  12. The regulation of the human corpus luteum steroidogenesis: a hypothesis?

    PubMed

    Oon, V J; Johnson, M R

    2000-01-01

    The corpus luteum (CL) is an important endocrine organ in the menstrual cycle and in pregnancy. The regulation of its hormonal production has been extensively studied. The steroidogenic abilities of the CL can be rescued by human chorionic gonadotrophin (HCG) but its role in the maintenance of CL function is not clear. We will discuss the hypothesis that there are fetoplacental factors, other than HCG, that modulate CL steroidogenesis.

  13. Annotated chemical patent corpus: a gold standard for text mining.

    PubMed

    Akhondi, Saber A; Klenner, Alexander G; Tyrchan, Christian; Manchala, Anil K; Boppana, Kiran; Lowe, Daniel; Zimmermann, Marc; Jagarlapudi, Sarma A R P; Sayle, Roger; Kors, Jan A; Muresan, Sorel

    2014-01-01

    Exploring the chemical and biological space covered by patent applications is crucial in early-stage medicinal chemistry activities. Patent analysis can provide understanding of compound prior art, novelty checking, validation of biological assays, and identification of new starting points for chemical exploration. Extracting chemical and biological entities from patents through manual extraction by expert curators can take substantial amount of time and resources. Text mining methods can help to ease this process. To validate the performance of such methods, a manually annotated patent corpus is essential. In this study we have produced a large gold standard chemical patent corpus. We developed annotation guidelines and selected 200 full patents from the World Intellectual Property Organization, United States Patent and Trademark Office, and European Patent Office. The patents were pre-annotated automatically and made available to four independent annotator groups each consisting of two to ten annotators. The annotators marked chemicals in different subclasses, diseases, targets, and modes of action. Spelling mistakes and spurious line break due to optical character recognition errors were also annotated. A subset of 47 patents was annotated by at least three annotator groups, from which harmonized annotations and inter-annotator agreement scores were derived. One group annotated the full set. The patent corpus includes 400,125 annotations for the full set and 36,537 annotations for the harmonized set. All patents and annotated entities are publicly available at www.biosemantics.org.

  14. Annotated Chemical Patent Corpus: A Gold Standard for Text Mining

    PubMed Central

    Akhondi, Saber A.; Klenner, Alexander G.; Tyrchan, Christian; Manchala, Anil K.; Boppana, Kiran; Lowe, Daniel; Zimmermann, Marc; Jagarlapudi, Sarma A. R. P.; Sayle, Roger; Kors, Jan A.; Muresan, Sorel

    2014-01-01

    Exploring the chemical and biological space covered by patent applications is crucial in early-stage medicinal chemistry activities. Patent analysis can provide understanding of compound prior art, novelty checking, validation of biological assays, and identification of new starting points for chemical exploration. Extracting chemical and biological entities from patents through manual extraction by expert curators can take substantial amount of time and resources. Text mining methods can help to ease this process. To validate the performance of such methods, a manually annotated patent corpus is essential. In this study we have produced a large gold standard chemical patent corpus. We developed annotation guidelines and selected 200 full patents from the World Intellectual Property Organization, United States Patent and Trademark Office, and European Patent Office. The patents were pre-annotated automatically and made available to four independent annotator groups each consisting of two to ten annotators. The annotators marked chemicals in different subclasses, diseases, targets, and modes of action. Spelling mistakes and spurious line break due to optical character recognition errors were also annotated. A subset of 47 patents was annotated by at least three annotator groups, from which harmonized annotations and inter-annotator agreement scores were derived. One group annotated the full set. The patent corpus includes 400,125 annotations for the full set and 36,537 annotations for the harmonized set. All patents and annotated entities are publicly available at www.biosemantics.org. PMID:25268232

  15. An Integration of Corpus-Based and Genre-Based Approaches to Text Analysis in Eap/esp: Countering Criticisms against Corpus-Based Methodologies

    ERIC Educational Resources Information Center

    Flowerdew, L.

    2005-01-01

    In the past few years, several corpus-based studies have been carried out which either explicitly in some cases, but more subtly in others, draw on aspects of genre theory for their analyses. The purpose of this paper is to review those corpus studies which specifically draw on either the English for Specific Purposes (following the Swales…

  16. Recent Developments in Corpus Linguistics and Corpus-Based Research/Department of Linguistics and Modern Language Studies at the Hong Kong Institute of Education

    ERIC Educational Resources Information Center

    Xie, Qin

    2015-01-01

    Corpus linguistics has transformed the landscape of empirical research on languages in recent decades. The proliferation of corpus technology has enabled researchers worldwide to conduct research in their own geographical locations with few hindrances. It has become increasingly commonplace for researchers to compile their own corpora for specific…

  17. The Effects of Utilizing Corpus Resources to Correct Collocation Errors in L2 Writing--Students' Performance, Corpus Use and Perceptions

    ERIC Educational Resources Information Center

    Wu, Yi-ju

    2016-01-01

    Data-Driven Learning (DDL), in which learners "confront [themselves] directly with the corpus data" (Johns, 2002, p. 108), has shown to be effective in collocation learning in L2 writing. Nevertheless, there have been only few research studies of this type examining the relationship between English proficiency and corpus consultation.…

  18. 33 CFR 334.800 - Corpus Christi Bay, Tex.; seaplane restricted area, U.S. Naval Air Station, Corpus Christi.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE DANGER ZONE AND... follows: Beginning at a point on the south shore of Corpus Christi Bay at the “North Gate” of the U.S...′41.6″ 97°15′33.3″ thence to a point on shore at latitude 27°40′44.9″ N.; thence along the shore...

  19. 33 CFR 334.800 - Corpus Christi Bay, Tex.; seaplane restricted area, U.S. Naval Air Station, Corpus Christi.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE DANGER ZONE AND... follows: Beginning at a point on the south shore of Corpus Christi Bay at the “North Gate” of the U.S...′41.6″ 97°15′33.3″ thence to a point on shore at latitude 27°40′44.9″ N.; thence along the shore...

  20. Unrepaired Tetralogy of Fallot with Absent Pulmonary Valve in a Mildly Symptomatic 16-Year-Old Boy

    PubMed Central

    Drogalis-Kim, Diana E.; Reemtsen, Brian L.

    2016-01-01

    Absent pulmonary valve is a rare and severe variant seen in only 3% to 6% of patients with tetralogy of Fallot. Fetuses with this combined condition who survive through birth typically need intervention in infancy or early childhood because of respiratory distress, heart failure, or failure to thrive. We describe the unusual case of a mildly symptomatic 16-year-old boy with these conditions who underwent successful primary repair. Our search of the medical literature yielded fewer than 5 cases of tetralogy of Fallot with absent pulmonary valve (or variants with an absent left pulmonary artery) and survival without repair into later adolescence or adulthood. PMID:28100972

  1. Computerized axial tomography of the chest for visualization of ''absent'' pulmonary arteries

    SciTech Connect

    Sondheimer, H.M.; Oliphant, M.; Schneider, B.; Kavey, R.E.W.; Blackman, M.S.; Parker, F.B. Jr.

    1982-05-01

    To expand the search for central pulmonary arteries in six patients with absence of cardiac-pulmonary continuity, computerized axial tomography (CAT) of the chest was performed. The CAT scans were compared with previous arteriograms and pulmonary vein wedge angiograms. Three patients with type IV truncus arteriosus were studied, and none had a central, right or left pulmonary artery on CAT scan. However, two patients with tetralogy of Fallot with pulmonary atresia and a patent ductus arteriosus to the right lung demonstrated the presence of a left pulmonary artery. In addition, one child with truncus arteriosus with ''absent'' left pulmonary artery demonstrated a left pulmonary artery on the CAT scan. The CAT scan may therefore enhance our ability to search for disconnected pulmonary arteries in children with complex cyanotic congenital heart disease.

  2. Absent or reversed end diastolic flow velocity in the umbilical artery and necrotising enterocolitis.

    PubMed Central

    Malcolm, G; Ellwood, D; Devonald, K; Beilby, R; Henderson-Smart, D

    1991-01-01

    Absent or reversed end diastolic flow (AREDF) velocities in the umbilical artery were identified in 25 high risk pregnancies. In six pregnancies the fetus was abnormal and all but one of these ended in perinatal death. Of the 19 morphologically normal fetuses, three died in utero and there were four neonatal or infant deaths. The mortality rate was 48% for all pregnancies and 37% for those with morphologically normal fetuses. There was a highly significant increased risk for the development of necrotising enterocolitis in these morphologically normal fetuses with AREDF (53%) compared with controls (6%) who did have umbilical artery end diastolic flow velocities in fetal life. There were no significant differences between the matched pairs for parameters of neonatal outcome chosen to reflect neonatal morbidity. These findings demonstrate the close association between AREDF and necrotising enterocolitis that appears to be independent of other variables such as degree of growth retardation, prematurity, and perinatal asphyxia. PMID:1863128

  3. Ejaculatory ducts opening into accessory urethral channel with hypospadias and absent verumontanum: a rare association.

    PubMed

    Ravi Kumar, Valkodai Ramanthan; Duraisami, Vijayagiri

    2013-12-01

    Ejaculatory ducts draining into accessory urethral channel opening into perineum is rare. This is a case report of a 27-year-old male who had hypospadias surgery at 3 years of age, presenting with discharge of semen through the perineal opening from adolescence. Cystoscopy and dye study showed that it was a short channel communicating with both ejaculatory ducts. Cystoscopy of the native urethra revealed that the vermontanum had not developed. The mucous lined accessory urethra was anastomosed to the bulbar urethra. Urethrogram done after one year showed that the accessory urethra was draining well into the bulbar urethra. Such type of accessory urethral channel communicating with ejaculatory ducts and associated with hypospadias and absent vermontanum has not been reported so far.

  4. Delayed emergence from anesthesia associated with absent brainstem reflexes following suboccipital craniotomy.

    PubMed

    Munis, James R; Marcukaitis, Anthony W; Sprung, Juraj

    2006-01-01

    One of the most feared complications after intracranial surgery is development of acute intracranial pathology, which may result in hypoperfusion and brain injury. Thus, early neurological assessment, performed in the operating room immediately after emergence from anesthesia, is a practice that may contribute to timely diagnosis of neurosurgical complications. Failure to awake after general anesthesia precludes conductance of neurological assessment. We report a patient who failed to emerge from anesthesia after suboccipital craniotomy and had absent brain-stem reflexes with fixed and dilated pupils consistent with severe brain injury. Approximately 60 minutes after termination of surgery, the patient suddenly woke up. After the fact, we discovered that the neurosurgeon performed a generous field block with bupivacaine along the neck incision line. We presume that our patient's failure to awaken was caused by paralysis of brain-stem caused by migration of bupivacaine from the site of the injection.

  5. Morphologic Response to a New Inlet, Packery Channel, Corpus Christi, Texas

    DTIC Science & Technology

    2007-01-01

    terminology, Aransas Pass (shared with Aransas Bay to the north) on the north side and Corpus Christi Pass on the south side, in the SSE corner (Fig...1 and Fig. 2). Dredging of Aransas Pass started in 1912, and its re-direction into Corpus Christi Bay in 1924 caused Corpus Christi Pass to slowly...rather than the 23-mile (37 km) transit to Aransas Pass. The North Padre Island (Packery Channel), Nueces County, Texas, Storm Damage Reduction

  6. What’s In a Note: Construction of a Suicide Note Corpus

    PubMed Central

    Pestian, John P.; Matykiewicz, Pawel; Linn-Gust, Michelle

    2012-01-01

    This paper reports on the results of an initiative to create and annotate a corpus of suicide notes that can be used for machine learning. Ultimately, the corpus included 1,278 notes that were written by someone who died by suicide. Each note was reviewed by at least three annotators who mapped words or sentences to a schema of emotions. This corpus has already been used for extensive scientific research. PMID:23170067

  7. Silent dropouts in health surveys: are nonrespondent absent teenagers different from those who participate in school-based health surveys?

    PubMed

    Michaud, P A; Delbos-Piot, I; Narring, F

    1998-04-01

    3324 in-school students aged 15-20 years randomly selected from high schools and professional centers in francophone Switzerland answered a self-administered questionnaire about their health problems, needs, and behavior. Their responses were compared with those of 96 absent students sampled via telephone on a shorter, but similar questionnaire. Relative to the absent students, a significantly higher percentage of in-school students reported skin problems, weight concerns, sleep problems, headaches, stomach aches, and vision or dental problems. The percentages of students reporting a need for help were also higher among present students than among those who were absent: nutrition, 21.8 vs. 9.4; stress, 44.2 vs. 31.3; depression, 28.4 vs. 18.9; sleep problems, 21.3 vs. 12.1; sports, 9.2 vs. 4.2; and love life, 31.5 vs. 14.5. The rates of hospitalization and injuries were lower among absent students, 28.2 vs. 40.1. A higher proportion of absent students were sexually active and they also had a tendency to use tobacco, alcohol, and cannabis more often than did present students. Absent students also more frequently partook of leisure and group activities. Study findings suggest that within the Swiss context, school absenteeism is probably related less to physical or chronic health problems than to hedonistic lifestyles which predispose some students skip part of the school hours.

  8. 33 CFR 165.809 - Security Zones; Port of Port Lavaca-Point Comfort, Point Comfort, TX and Port of Corpus Christi...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Lavaca-Point Comfort, Point Comfort, TX and Port of Corpus Christi Inner Harbor, Corpus Christi, TX. 165... Lavaca-Point Comfort, Point Comfort, TX and Port of Corpus Christi Inner Harbor, Corpus Christi, TX. (a) Location. The following area is designated as a security zone: all waters of the Corpus Christi...

  9. Endocrine and Local Control of the Primate Corpus Luteum

    PubMed Central

    Stouffer, Richard L.; Bishop, Cecily V.; Bogan, Randy L.; Xu, Fuhua; Hennebold, Jon D.

    2014-01-01

    The primate corpus luteum is a transient endocrine gland that differentiates from the ovulatory follicle midway through the ovarian (menstrual) cycle. Its formation and limited lifespan is critical for fertility, as luteal-derived progesterone is the essential steroid hormone required for embryo implantation and maintenance of intra-uterine pregnancy until the placenta develops. It is well-established that LH and the LH-like hormone, CG, are the vital luteotropic hormones during the menstrual cycle and early pregnancy, respectively. Recent advances, particularly through genome analyses and cellular studies, increased our understanding of various local factors and cellular processes associated with the development, maintenance and repression of the corpus luteum. These include paracrine or autocrine factors associated with angiogenesis (e.g., VEGF), and that mediate LH/CG actions (e.g., progesterone), or counteract luteotropic effects (i.e., local luteolysis; e.g., PGF2α). However, areas of mystery and controversy remain, particularly regarding the signals and events that initiate luteal regression in the non-fecund cycle. Novel approaches capable of gene “knockdown” or amplification”, in vivo as well as in vitro, should identify novel or underappreciated gene products that are regulated by or modulate LH/CG actions to control the functional lifespan of the primate corpus luteum. Further advances in our understanding of luteal physiology will help to improve or control fertility for purposes ranging from preservation of endangered primate species to designing novel ovary-based contraceptives and treating ovarian disorders in women. R01 HD020869, R01 HD042000, U54 HD018185, U54 HD055744, P51 OD011092, T32 HD007133, Bayer Schering Pharma AG. PMID:24287034

  10. Molecular genetic analysis of Drosophila eyes absent mutants reveals an eye enhancer element.

    PubMed Central

    Zimmerman, J E; Bui, Q T; Liu, H; Bonini, N M

    2000-01-01

    The eyes absent (eya) gene is critical for normal eye development in Drosophila and is highly conserved to vertebrates. To define regions of the gene critical for eye function, we have defined the mutations in the four viable eya alleles. Two of these mutations are eye specific and undergo transvection with other mutations in the gene. These were found to be deletion mutations that remove regulatory sequence critical for eye cell expression of the gene. Two other viable alleles cause a reduced eye phenotype and affect the function of the gene in additional tissues, such as the ocelli. These mutations were found to be insertion mutations of different transposable elements within the 5' UTR of the transcript. Detailed analysis of one of these revealed that the transposable element has become subject to regulation by eye enhancer sequences of the eya gene, disrupting normal expression of EYA in the eye. More extended analysis of the deletion region in the eye-specific alleles indicated that the deleted region defines an enhancer that activates gene expression in eye progenitor cells. This enhancer is responsive to ectopic expression of the eyeless gene. This analysis has defined a critical regulatory region required for proper eye expression of the eya gene. PMID:10628984

  11. Molecular analysis of Drosophila eyes absent mutants reveals features of the conserved Eya domain.

    PubMed Central

    Bui, Q T; Zimmerman, J E; Liu, H; Bonini, N M

    2000-01-01

    The eyes absent (eya) gene is critical to eye formation in Drosophila; upon loss of eya function, eye progenitor cells die by programmed cell death. Moreover, ectopic eya expression directs eye formation, and eya functionally synergizes in vivo and physically interacts in vitro with two other genes of eye development, sine oculis and dachshund. The Eya protein sequence, while highly conserved to vertebrates, is novel. To define amino acids critical to the function of the Eya protein, we have sequenced eya alleles. These mutations have revealed that loss of the entire Eya Domain is null for eya activity, but that alleles with truncations within the Eya Domain display partial function. We then extended the molecular genetic analysis to interactions within the Eya Domain. This analysis has revealed regions of special importance to interaction with Sine Oculis or Dachshund. Select eya missense mutations within the Eya Domain diminished the interactions with Sine Oculis or Dachshund. Taken together, these data suggest that the conserved Eya Domain is critical for eya activity and may have functional subregions within it. PMID:10835393

  12. Identification of Transcriptional Targets of the Dual Function Transcription Factor/Phosphatase Eyes Absent

    PubMed Central

    Jemc, Jennifer; Rebay, Ilaria

    2007-01-01

    Drosophila eye specification and development relies on a collection of transcription factors termed the retinal determination gene network (RDGN). Two members of this network, Eyes absent (EYA) and Sine oculis (SO), form a transcriptional complex in which EYA provides the transactivation function while SO provides the DNA binding activity. EYA also functions as a protein tyrosine phosphatase, raising the question of whether transcriptional output is dependent or independent of phosphatase activity. To explore this, we used microarrays together with binding site analysis, quantitative real-time PCR, chromatin immunoprecipitation, genetics and in vivo expression analysis to identify new EYA-SO targets. In parallel, we examined the expression profiles of tissue expressing phosphatase mutant eya and found that reducing phosphatase activity did not globally impair transcriptional output. Among the targets identified by our analysis was the cell cycle regulatory gene, string (stg), suggesting that EYA and SO may influence cell proliferation through transcriptional regulation of stg. Future investigation into the regulation of stg and other EYA-SO targets identified in this study will help elucidate the transcriptional circuitries whereby output from the RDGN integrates with other signaling inputs to coordinate retinal development. PMID:17714699

  13. Terminal hemimelia of the lower extremity: absent lateral ray and a normal fibula

    PubMed Central

    Kim, Jae Kwang; Chung, Moon Sang; Lee, Sang Ki

    2007-01-01

    Congenital lateral ray deficiency is considered to be a manifestation of fibular hemimelia. However, we have noted patients with absent lateral ray but stable knee and ankle joints, and named this condition terminal hemimelia of the lower extremity. This study was undertaken to further define this group of patients and to compare these patients with fibular hemimelia patients. Four boys and one girl of mean age six years two months were in the terminal hemimelic group and four boys and three girls of mean age eight years seven months in the fibular hemimelic group at the final evaluation. Clinical features commonly observed in the fibular hemimelia such as knee valgus, knee instability, tibial bowing, ball and socket ankle, ankle instability, tarsal coalition, leg length inequality were compared between both groups. Terminal hemimelia of the lower extremity was the same as fibular hemimelia in clinical features below the ankle joint. However, terminal hemimela was found to be milder than fibular hemimelia in terms of limb shortening. The clinical features above the ankle joint were different between both groups. Knees and ankles were stable, and gait disturbance were rarely noticed in patients with terminal hemimelia of the lower extremity. PMID:17558505

  14. Effect of absent end diastolic flow velocity in the fetal umbilical artery on subsequent outcome

    PubMed Central

    Adiotomre, P.; Johnstone, F.; Laing, I.

    1997-01-01

    Sixty babies, delivered over a six and a half year period, who had absent end diastolic frequency (AEDF) in the umbilical artery, were studied. Individually matched control pregnancies for gestational age, birthweight, maternal clinical condition and date of delivery, in whom umbilical artery recordings showed end diastolic frequency, were also studied.
  Matching was achieved in 36 cases. Neonates from case pregnancies showed no increase in necrotising enterocolitis, intraventricular haemorrhage, pneumo-thorax, neonatal death or bronchopulmonary dysplasia. However, they were significantly less likely to require ventilation for respiratory distress syndrome (P=0.02).
  Although AEDF indicates a fetus under vascular stress, this finding alone will include a spectrum of response in the baby, from the well compensated to the irreversibly damaged. Delivery at different points in the deteriorating fetal environment may explain discrepant study results. This intrauterine stress, by increasing fetal corticosteroid and thyroid hormones, may account for enhanced lung maturity. Predictions of neonatal course need to be based on more comprehensive awareness of fetal status.

 Keywords: high risk pregnancies; end diastolic flow velocity; ventilation; respiratory distress syndrome. PMID:9059184

  15. Axillary Meristem Formation in Rice Requires the WUSCHEL Ortholog TILLERS ABSENT1[OPEN

    PubMed Central

    Tanaka, Wakana; Ohmori, Yoshihiro; Ushijima, Tomokazu; Matsusaka, Hiroaki; Matsushita, Tomonao; Kumamaru, Toshihiro; Kawano, Shigeyuki; Hirano, Hiro-Yuki

    2015-01-01

    Axillary shoot formation is a key determinant of plant architecture. Formation of the axillary shoot is regulated by initiation of the axillary meristem or outgrowth of the axillary bud. Here, we show that rice (Oryza sativa) TILLERS ABSENT1 (TAB1; also known as Os WUS), an ortholog of Arabidopsis thaliana WUS, is required to initiate axillary meristem development. We found that formation of the axillary meristem in rice proceeds via a transient state, which we term the premeristem, characterized by the expression of OSH1, a marker of indeterminate cells in the shoot apical meristem. In the tab1-1 (wus-1) mutant, however, formation of the axillary meristem is arrested at various stages of the premeristem zone, and OSH1 expression is highly reduced. TAB1/WUS is expressed in the premeristem zone, where it shows a partially overlapping pattern with OSH1. It is likely, therefore, that TAB1 plays an important role in maintaining the premeristem zone and in promoting the formation of the axillary meristem by promoting OSH1 expression. Temporal expression patterns of WUSCHEL-RELATED HOMEOBOX4 (WOX4) indicate that WOX4 is likely to regulate meristem maintenance instead of TAB1 after establishment of the axillary meristem. Lastly, we show that the prophyll, the first leaf in the secondary axis, is formed from the premeristem zone and not from the axillary meristem. PMID:25841039

  16. Corpus callosotomy in a patient with startle epilepsy.

    PubMed

    Gómez, Nicolás Garófalo; Hamad, Ana Paula; Marinho, Murilo; Tavares, Igor M; Carrete, Henrique; Caboclo, Luís Otávio; Yacubian, Elza Márcia; Centeno, Ricardo

    2013-03-01

    Startle epilepsy is a syndrome of reflex epilepsy in which the seizures are precipitated by a sudden and surprising, usually auditory, stimulus. We describe herein a girl who had been suffering with startle-induced seizures since 2 years of age. She had focal, tonic and tonic-clonic seizures, refractory to antiepileptic treatment. Daily tonic seizures led to very frequent falls and morbidity. Neurologically, she had no deficit. Interictal EEG showed slow waves and epileptiform discharges in central and fronto-central regions. Video-polygraphic recordings of seizures, triggered by stimuli, showed generalised symmetric tonic posturing with ictal EEG, characterised by an abrupt and diffuse electrodecremental pattern of fast activity, followed by alpha-theta rhythm superimposed by epileptic discharges predominantly over the vertex and anterior regions. Magnetic resonance imaging showed no abnormalities. Corpus callosotomy was performed when the patient was 17. Since surgery, the patient (one year follow-up) has remained seizure-free. Corpus callosotomy may be considered in patients with startle epilepsy and tonic seizures, in the absence of focal lesions amenable to surgery. [Published with video sequences].

  17. Late outcomes for the surgical management of absent pulmonary valve syndrome in infants

    PubMed Central

    Hu, Renjie; Zhang, Haibo; Xu, Zhiwei; Liu, Jinfen; Su, Zhaokang; Ding, Wenxiang

    2013-01-01

    OBJECTIVES Absent pulmonary valve syndrome (APVS) is a rare cardiac malformation that is usually associated with aneurysmal dilatation of pulmonary arteries and respiratory distress. The surgical mortality of neonates and infants with APVS has decreased tremendously, from 60% in 1980s to 10–20% recently. This study retrospectively reviews surgical outcomes of our 10-year experience in patients with APVS. METHODS From 2002 to 2012, 42 patients with APVS underwent surgical correction. Thirty-seven patients had APVS as a variant of tetralogy of Fallot, 4 with double outlet right ventricle and 1 with ventricular septal defect. Respiratory distress was present in 12 infants. Four patients needed continuous positive airway pressure and 5 required intubation with mechanical ventilation before surgery. RESULTS There was no hospital death and 3 late deaths. The mean follow-up time was 62.71 ± 34.31 months. Significant differences were found in the duration of postoperative ventilation between patients with or without respiratory distress (P = 0.009) and patients with left or right aortic arch (P = 0.012). The Kaplan–Meier curve indicated that overall survival at 5 and 10 years was 92.4%. The survival rates between patients with or without respiratory distress were 72.7 and 100%, respectively (P = 0.003). Overall mortality was associated with longer cardiopulmonary bypass time (P = 0.004) and lower weight at operation (P = 0.042). There were no significant differences in survival and postoperative data such as the duration of ventilation or intensive care unit stay and New York Heart Association class among the three methods of right ventricular outflow tract (RVOT) reconstruction. CONCLUSIONS Surgical treatment of APVS has got favourable outcomes in terms of mortality and reoperation rate. Different methods of RVOT reconstruction do not affect the surgical outcome. Patients required long-term follow-up for postoperative respiratory complications secondary to persistent

  18. Is CFTR-delF508 Really Absent from the Apical Membrane of the Airway Epithelium?

    PubMed Central

    Borthwick, Lee A.; Botha, Phil; Verdon, Bernard; Brodlie, Malcolm J.; Gardner, Aaron; Bourn, David; Johnson, Gail E.

    2011-01-01

    Background Understanding where mutant CFTR is localised in airway epithelia is essential in guiding the best therapeutic approach to correct the dysfunction of the CFTR protein. The widely held paradigm is that CF patients harbouring the commonest mutation, CFTR-delF508, trap CFTR within the endoplasmic reticulum and target it for degradation. However there are conflicting reports concerning expression and localisation of CFTR-delF508 in lung tissue. To attempt to resolve this fundamental issue we developed a novel approach to measure CFTR-delF508 in the lower airways of patients who have undergone lung transplantation for advanced CF. By sampling CF and non-CF epithelium simultaneously from the same individual, confounding factors of different airway microenvironments which may have influenced previous observations can be overcome. Methods Epithelia sampled by bronchial brushing above (CF) and below (non-CF) the bronchial anastomosis were stained for CFTR and the localisation and level of expression assessed (n = 12). Results There was no significant difference in the proportion of tall columnar cells showing CFTR immunostaining as a discrete band at the apical membrane in cells harbouring the CFTR-delF508 mutation compared to non-CF cells (p = 0.21, n = 12). However, the amount of CFTR expressed at the apical surface was reduced by ∼50% in CF cells compared to non-CF cells (p = 0.04, n = 5). Conclusions Our novel observation challenges the prevailing paradigm that CFTR is essentially absent from the apical membrane of respiratory cells harbouring the CFTR-delF508 mutation. Moreover, it raises the possibility that the new generation of CFTR potentiators may offer a realistic therapeutic option for CF patients. PMID:21826241

  19. Duck TRIM27-L enhances MAVS signaling and is absent in chickens and turkeys.

    PubMed

    Blaine, Alysson H; Miranzo-Navarro, Domingo; Campbell, Lee K; Aldridge, Jerry R; Webster, Robert G; Magor, Katharine E

    2015-10-01

    Wild waterfowl, including mallard ducks, are the natural reservoir of avian influenza A virus and they are resistant to strains that would cause fatal infection in chickens. Here we investigate potential involvement of TRIM proteins in the differential response of ducks and chickens to influenza. We examine a cluster of TRIM genes located on a single scaffold in the duck genome, which is a conserved synteny group with a TRIM cluster located in the extended MHC region in chickens and turkeys. We note a TRIM27-like gene is present in ducks, and absent in chickens and turkeys. Orthologous genes are predicted in many birds and reptiles, suggesting the gene has been lost in chickens and turkeys. Using quantitative real-time PCR (qPCR) we show that TRIM27-L, and the related TRIM27.1, are upregulated 5- and 9-fold at 1 day post-infection with highly pathogenic A/Vietnam/1203/2004. To assess whether TRIM27.1 or TRIM27-L are involved in modulation of antiviral gene expression, we overexpressed them in DF1 chicken cells, and neither show any direct effect on innate immune gene expression. However, when co-transfected with duck RIG-I-N (d2CARD) to constitutively activate the MAVS pathway, TRIM27.1 weakly decreases, while TRIM27-L strongly activates innate immune signaling leading to increased transcription of antiviral genes MX1 and IFN-β. Furthermore, when both are co-expressed, the activation of the MAVS signaling pathway by TRIM27-L over-rides the inhibition by TRIM27.1. Thus, ducks have an activating TRIM27-L to augment MAVS signaling following RIG-I detection, while chickens lack both TRIM27-L and RIG-I itself.

  20. A Quantitative Corpus-Based Approach to English Spatial Particles: Conceptual Symmetry and Its Pedagogical Implications

    ERIC Educational Resources Information Center

    Chen, Alvin Cheng-Hsien

    2014-01-01

    The present study aims to investigate how conceptual symmetry plays a role in the use of spatial particles in English and to further examine its pedagogical implications via a corpus-based evaluation of the course books in senior high schools in Taiwan. More specifically, we adopt a quantitative corpus-based approach to investigate whether bipolar…

  1. An Evaluation of an Online Bilingual Corpus for the Self-Learning of Legal English.

    ERIC Educational Resources Information Center

    Fan, May; Xunfeng, Xu

    2002-01-01

    Introduces a bilingual corpus of legal and documentary texts in English and Chinese and reports a study that sought to evaluate the usefulness of the corpus in the self-learning of legal English. Subjects were Chinese students doing a degree in translation at a university in Hong Kong, where English common law is still used since the handover of…

  2. A Corpus-Based Approach to Online Materials Development for Writing Research Articles

    ERIC Educational Resources Information Center

    Chang, Ching-Fen; Kuo, Chih-Hua

    2011-01-01

    There has been increasing interest in the possible applications of corpora to both linguistic research and pedagogy. This study takes a corpus-based, genre-analytic approach to discipline-specific materials development. Combining corpus analysis with genre analysis makes it possible to develop teaching materials that are not only authentic but…

  3. TOEFL11: A Corpus of Non-Native English. Research Report. ETS RR-13-24

    ERIC Educational Resources Information Center

    Blanchard, Daniel; Tetreault, Joel; Higgins, Derrick; Cahill, Aoife; Chodorow, Martin

    2013-01-01

    This report presents work on the development of a new corpus of non-native English writing. It will be useful for the task of native language identification, as well as grammatical error detection and correction, and automatic essay scoring. In this report, the corpus is described in detail.

  4. The Use of Corpus Concordancing for Second Language Learners' Self Error-Correction

    ERIC Educational Resources Information Center

    Feng, Hui-Hsien

    2014-01-01

    Corpus concordancing has been utilized in second language (L2) writing classrooms for a few decades. Some studies have shown that this application is helpful, to a certain degree, to learners' writing process. However, how corpus concordancing is utilized for nonnative speakers' (NNSs) self error-correction in writing, especially the pattern of…

  5. The Pedagogical Mediation of a Developmental Learner Corpus for Classroom-Based Language Instruction

    ERIC Educational Resources Information Center

    Belz, Julie A.; Vyatkina, Nina

    2008-01-01

    Although corpora have been used in language teaching for some time, few empirical studies explore their impact on learning outcomes. We provide a microgenetic account of learners' responses to corpus-driven instructional units for German modal particles and pronominal "da"-compounds. The units are based on developmental corpus data produced by…

  6. Using Edit Distance to Analyse Errors in a Natural Language to Logic Translation Corpus

    ERIC Educational Resources Information Center

    Barker-Plummer, Dave; Dale, Robert; Cox, Richard; Romanczuk, Alex

    2012-01-01

    We have assembled a large corpus of student submissions to an automatic grading system, where the subject matter involves the translation of natural language sentences into propositional logic. Of the 2.3 million translation instances in the corpus, 286,000 (approximately 12%) are categorized as being in error. We want to understand the nature of…

  7. English Collocation Learning through Corpus Data: On-Line Concordance and Statistical Information

    ERIC Educational Resources Information Center

    Ohtake, Hiroshi; Fujita, Nobuyuki; Kawamoto, Takeshi; Morren, Brian; Ugawa, Yoshihiro; Kaneko, Shuji

    2012-01-01

    We developed an English Collocations On Demand system offering on-line corpus and concordance information to help Japanese researchers acquire a better command of English collocation patterns. The Life Science Dictionary Corpus consists of approximately 90,000,000 words collected from life science related research papers published in academic…

  8. The BioScope corpus: biomedical texts annotated for uncertainty, negation and their scopes

    PubMed Central

    Vincze, Veronika; Szarvas, György; Farkas, Richárd; Móra, György; Csirik, János

    2008-01-01

    Background Detecting uncertain and negative assertions is essential in most BioMedical Text Mining tasks where, in general, the aim is to derive factual knowledge from textual data. This article reports on a corpus annotation project that has produced a freely available resource for research on handling negation and uncertainty in biomedical texts (we call this corpus the BioScope corpus). Results The corpus consists of three parts, namely medical free texts, biological full papers and biological scientific abstracts. The dataset contains annotations at the token level for negative and speculative keywords and at the sentence level for their linguistic scope. The annotation process was carried out by two independent linguist annotators and a chief linguist – also responsible for setting up the annotation guidelines – who resolved cases where the annotators disagreed. The resulting corpus consists of more than 20.000 sentences that were considered for annotation and over 10% of them actually contain one (or more) linguistic annotation suggesting negation or uncertainty. Conclusion Statistics are reported on corpus size, ambiguity levels and the consistency of annotations. The corpus is accessible for academic purposes and is free of charge. Apart from the intended goal of serving as a common resource for the training, testing and comparing of biomedical Natural Language Processing systems, the corpus is also a good resource for the linguistic analysis of scientific and clinical texts. PMID:19025695

  9. Use of Corpus in the Business English Classroom: From Lesser to More Specific.

    ERIC Educational Resources Information Center

    Fuentes, Alejandro Curado; Rokowski, Patricia Edwards

    The integration of a corpus-based approach in the English for Specific Purposes (ESP) syllabus is one possible course design step in university settings. This paper describes a situation in which Business English is taught by incorporating corpus-driven knowledge and communicative task feedback. Two main goals are pursued in this reciprocal…

  10. A Corpus-Based Study on English Prepositions of Place, "In" and "On"

    ERIC Educational Resources Information Center

    Arjan, Asmeza; Abdullah, Noor Hayati; Roslim, Norwati

    2013-01-01

    This corpus-based study examined the usage, mastery and developmental pattern (Norwati, 2004) of English prepositions of place, "in" and "on" across three different academic levels namely Form 4, Form 5 and College students. The Malaysian Corpus of Students Argumentative Writing (MCSAW) was used as the source of data in…

  11. The Effect of Corpus Assisted Language Teaching on the Learners' Proper Use of Punctuation Marks

    ERIC Educational Resources Information Center

    Celik, Serkan; Elkatmis, Metin

    2013-01-01

    One of the critical contributions of the emerging technologies in computer sciences is the capability of corpus compilation and processing. Corpus resources and approaches are regarded as a potentially valuable areas both in developing instructional methods and designing pedagogical materials. This study aimed to explore the effect of exposing…

  12. An Empirical Study on Corpus-Driven English Vocabulary Learning in China

    ERIC Educational Resources Information Center

    Binkai, Jiao

    2012-01-01

    This paper focuses on the autonomous English vocabulary learning in corpus-based contexts. Language teaching practice is becoming more learner-centered in the field of language teaching, learner autonomy has been an ongoing concern of foreign language educators in china. As an assistant tool in language learning, corpus makes an easy and quick…

  13. The Preference for Self-Correction in a Tai Conversational Corpus

    ERIC Educational Resources Information Center

    Moerman, Michael

    1977-01-01

    The organization of repair in a corpus of conversations in the Lue, Yuan (or Myang), and Siamese dialects of Tai is examined with regard to the preference for self-correction described previously for an English corpus. In both, repair is an identically organized sequential phenomenon involving repair segments during conversation. (CHK)

  14. Linking Adverbials in First-Year Korean University EFL Learners' Writing: A Corpus-Informed Analysis

    ERIC Educational Resources Information Center

    Ha, Myung-Jeong

    2016-01-01

    This study examines the frequency and usage patterns of linking adverbials in Korean students' essay writing in comparison with native English writing. The learner corpus used in the present study is composed of 105 essays that were produced by first-year university students in Korea. The control corpus was taken from the American LOCNESS…

  15. Language with Character: A Stratified Corpus Comparison of Individual Differences in E-Mail Communication

    ERIC Educational Resources Information Center

    Oberlander, Jon; Gill, Alastair J.

    2006-01-01

    To what extent does the wording and syntactic form of people's writing reflect their personalities? Using a bottom-up stratified corpus comparison, rather than the top-down content analysis techniques that have been used before, we examine a corpus of e-mail messages elicited from individuals of known personality, as measured by the Eysenck…

  16. Capturing L2 Accuracy Developmental Patterns: Insights from an Error-Tagged EFL Learner Corpus

    ERIC Educational Resources Information Center

    Thewissen, Jennifer

    2013-01-01

    The present article addresses the issue of second language accuracy developmental trajectories and shows how they can be captured via an error-tagged version of an English as a Foreign Language (EFL) learner corpus. The data used in this study were extracted from the International Corpus of Learner English (Granger et al., 2009) and consist of a…

  17. A Corpus-Based Discourse Analysis of the Vision and Mission Statements of Universities in Turkey

    ERIC Educational Resources Information Center

    Efe, Ibrahim; Ozer, Omer

    2015-01-01

    This article presents findings from a corpus-assisted discourse analysis of mission and vision statements of 105 state and 66 private/foundation universities in Turkey. The paper combines a corpus-based approach with critical discourse analysis to interpret the data in relation to its institutional as well as socio-political context. It argues…

  18. A Corpus-Based View of Lexical Gender in Written Business English

    ERIC Educational Resources Information Center

    Fuertes-Olivera, Pedro A.

    2007-01-01

    This article investigates lexical gender in specialized communication. The key method of analysis is that of forms of address, professional titles, and "generic man" in a 10 million word corpus of written Business English. After a brief introduction and literature review on both gender in specialized communication and similar corpus-based views of…

  19. Interface Conditions on Postverbal Subjects: A Corpus Study of L2 English

    ERIC Educational Resources Information Center

    Lozano, Cristobal; Mendikoetxea, Amaya

    2010-01-01

    This paper investigates how syntactic knowledge interfaces with other cognitive systems by analysing the production of postverbal subjects, V(erb)-S(ubject) order, in an L1 Spanish-L2 English corpus and a comparable English native corpus. VS order in both native and L2 English is shown to be constrained by properties operating at three interfaces:…

  20. Lexical Properties of Slovene Sign Language: A Corpus-Based Study

    ERIC Educational Resources Information Center

    Vintar, Špela

    2015-01-01

    Slovene Sign Language (SZJ) has as yet received little attention from linguists. This article presents some basic facts about SZJ, its history, current status, and a description of the Slovene Sign Language Corpus and Pilot Grammar (SIGNOR) project, which compiled and annotated a representative corpus of SZJ. Finally, selected quantitative data…