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  1. [Posterior reversible encephalopathy syndrome].

    PubMed

    Fischer, M; Schmutzhard, E

    2016-06-01

    Posterior reversible encephalopathy syndrome refers to a neurological disorder characterized by headache, disorders of consciousness, visual disturbances, epileptic seizures, and subcortical vasogenic edema. About two thirds of patients develop neurological symptoms, which are associated with blood pressure fluctuations. One hypothesis is that hypertensive episodes cause autoregulatory failure, and values above the upper limit of cerebral autoregulation result in a breakthrough followed by hyperperfusion and blood-brain barrier dysfunction. In another hypothesis, endothelial dysfunction triggered by numerous factors including preeclampsia, immunosuppressive agents, chemotherapeutics, sepsis, or autoimmune disorders is thought to be the key pathomechanism. Endo- or exogenic toxic agents including pharmacological substances, cytokines, or bacterial toxins are supposed to trigger endothelial activation and dysfunction resulting in the release of vasoconstrictors, pro-inflammatory mediators, and vascular leakage. Diagnosis is usually based on clinical and neuroimaging findings that frequently show a bilateral, symmetric, and parietooccipital pattern. However, the diagnosis can often only be confirmed during the course of disease after excluding important differential diagnoses. Currently, there is no specific treatment available. Lowering of arterial blood pressure and eliminating the underlying cause usually leads to an improvement of clinical and neuroradiological findings. Admission to a critical care unit is required in about 40 % of patients due to complicating conditions including status epilepticus, cerebral vasoconstriction, ischemia, or intracerebral hemorrhage. Prognosis is favorable; in the majority of patients neurological deficits and imaging findings resolve completely. PMID:27272329

  2. Sickle cell disease and posterior reversible leukoencephalopathy.

    PubMed

    Geevasinga, Nimeshan; Cole, Catherine; Herkes, Geoffrey K; Barnett, Yael; Lin, Jamie; Needham, Merrilee

    2014-08-01

    Sickle cell disease can present with neurological manifestations. One such presentation is with posterior reversible leukoencephalopathy also known as reversible posterior leukoencephalopathy. The condition is classically described as reversible over time; it commonly presents with oedematous changes involving the white matter of the occipital and parietal regions. Only a few patients with the association between sickle cell disease and posterior reversible leukoencephalopathy have been described in the adult literature. We present two patients from our institutions to emphasise the association between the two conditions and summarise the published cases in the literature. PMID:24656986

  3. Isolated Posterior Fossa Involvement in Posterior Reversible Encephalopathy Syndrome

    PubMed Central

    Shimizu, Yukie; Tha, Khin Khin; Iguchi, Akihiro; Cho, Yuko; Yoshida, Atsushi; Fujima, Noriyuki; Tsukahara, Akiko; Shirato, Hiroki; Terae, Satoshi

    2013-01-01

    Summary Posterior reversible encephalopathy syndrome (PRES) is characterized by reversible vasogenic edema affecting the subcortical white matter of bilateral occipital and parietal lobes. We describe a case of isolated posterior fossa involvement of PRES which occurred during remission induction chemotherapy for T-cell acute lymphoblastic leukemia. Both the brainstem and cerebellum were extensively involved, but the supratentorial structures were completely spared. The follow-up magnetic resonance images revealed reversibility of most lesions. The knowledge of atypical radiological features of PRES is essential for prompt diagnosis. PMID:24199811

  4. Posterior Reversible Encephalopathy Syndrome in ALL.

    PubMed

    Millichap, J Gordon

    2015-07-01

    Investigators from Soochow University, Suzhou, China, studied the possible pathogenetic mechanisms and treatment of posterior reversible encephalopathy syndrome (PRES) observed in 11 cases of pediatric acute lymphoblastic leukemia (ALL) after induction chemotherapy. PMID:26933594

  5. Ciprofloxacin-associated posterior reversible encephalopathy

    PubMed Central

    Al Bu Ali, Waleed Hammad

    2013-01-01

    Posterior reversible encephalopathy syndrome (PRES) is a clinico-neuroradiological syndrome characterised by numerous symptoms and of no specific aetiology. Headache, confusion, seizures, cortical visual disturbances or blindness are the key symptoms. As this syndrome is reversible and readily treated by interrupting or discontinuing the aetiology, it should sharply be acknowledged. Ciprofloxacin was associated with PRES in an adolescent male treated from chest infection. It was managed in a hospital intensive care unit and was observed until disappearance. PMID:23585504

  6. Arthroscopic Reverse Remplissage for Posterior Instability.

    PubMed

    Lavender, Chad D; Hanzlik, Shane R; Pearson, Sara E; Caldwell, Paul E

    2016-02-01

    Posterior shoulder dislocation is an unusual injury often associated with electrical shock or seizure. As with anterior instability, patients frequently present with an impaction injury to the anterior aspect of the humeral head known as a "reverse Hill-Sachs lesion." The treatment of this bony defect is controversial, and multiple surgical procedures to fill the defect in an effort to decrease recurrence have been described. Most of the reports have focused on an open approach using variations of lesser tuberosity and subscapularis transfers, bone allograft, and even arthroplasty to assist with persistent instability. We advocate an arthroscopic technique that involves a suture anchor-based distal tenodesis of the subscapularis tendon or a reverse remplissage procedure. PMID:27073776

  7. Arthroscopic Reverse Remplissage for Posterior Instability

    PubMed Central

    Lavender, Chad D.; Hanzlik, Shane R.; Pearson, Sara E.; Caldwell, Paul E.

    2016-01-01

    Posterior shoulder dislocation is an unusual injury often associated with electrical shock or seizure. As with anterior instability, patients frequently present with an impaction injury to the anterior aspect of the humeral head known as a “reverse Hill-Sachs lesion.” The treatment of this bony defect is controversial, and multiple surgical procedures to fill the defect in an effort to decrease recurrence have been described. Most of the reports have focused on an open approach using variations of lesser tuberosity and subscapularis transfers, bone allograft, and even arthroplasty to assist with persistent instability. We advocate an arthroscopic technique that involves a suture anchor–based distal tenodesis of the subscapularis tendon or a reverse remplissage procedure. PMID:27073776

  8. Mycophenolate-Induced Posterior Reversible Encephalopathy Syndrome.

    PubMed

    Khajuria, Bhavik; Khajuria, Mansi; Agrawal, Yashwant

    2016-01-01

    A 29-year-old woman presented with diffuse anasarca and shortness of breath. Workup revealed a creatinine of 3.3 and a glomerular filtration rate of 17. The patient was also found to be pancytopenic with evidence of hemolytic anemia. A renal biopsy showed evidence of stage IV lupus nephritis with rapidly progressive glomerulonephritis. Her lupus was further classified as ANA negative and anti-dsDNA positive. Mycophenolate and triweekly hemodialysis were started along with a steroid burst of methylprednisolone 1 g for 3 days followed by prednisone 60 mg daily. Four days after discharge, the patient represented with a witnessed 3-minute seizure involving bowel incontinence, altered mental status, and tongue biting. She was given 2 mg intravenous lorazepam and loaded with 1000 mg levetiracetam for seizure prophylaxis. Magnetic resonance imaging of the head revealed bilateral posterior hemispheric subcortical edema, and the diagnosis of posterior reversible encephalopathy syndrome was made. Mycophenolate was immediately discontinued and replaced with cyclophosphamide. Strict blood pressure control below 140/90 mm Hg was maintained initially with intravenous nicardipine drip and then transitioned to oral nifedipine, clonidine, losartan, and minoxidil. A repeat head magnetic resonance imaging 8 days later showed resolved subcortical edema consistent with the patient's improved mental status. No permanent neurologic sequelae were recorded as a result of this hospital episode. PMID:25933141

  9. Posterior Reversible Encephalopathy Syndrome Complicating Traumatic Pancreatitis

    PubMed Central

    Sigurtà, Anna; Terzi, Valeria; Regna-Gladin, Caroline; Fumagalli, Roberto

    2016-01-01

    Abstract We are reporting a case of posterior reversible encephalopathy syndrome (PRES) developed in an unusual clinical scenario without the presence of the most described symptoms. PRES is a neurological and radiological syndrome described in many different clinical conditions. In children it has been mostly reported in association with hematological and renal disorders. Our patient was a 15 years old boy, admitted to our intensive care unit for pancreatitis after blunt abdominal trauma. During the stay in the intensive care unit, he underwent multiple abdominal surgical interventions for pancreatitis complications. He had a difficult management of analgesia and sedation, being often agitated with high arterial pressure, and he developed a bacterial peritonitis. After 29 days his neurological conditions abruptly worsened with neuroimaging findings consistent with PRES. His clinical conditions progressively improved after sedation and arterial pressure control. He was discharged at home with complete resolution of the neurological and imaging signs 2 months later. The pathophysiology of PRES is controversial and involves disordered autoregulation ascribable to hypertension and endothelial dysfunction. In this case both hypertension and endothelial activation, triggered by sepsis and pancreatitis, could represent the culprits of PRES onset. Even if there is no specific treatment for this condition, a diagnosis is mandatory to start antihypertensive and supportive treatment. We are therefore suggesting to consider PRES in the differential diagnosis of a neurological deterioration preceded by hypertension and/or septic state, even without other “typical” clinical features. PMID:27258506

  10. [Posterior reversible encephalopathy syndrome after neurosurgery: A literature review].

    PubMed

    Durán Paz, S; Moreno Casanova, I; Benatar-Haserfaty, J

    2015-12-01

    Posterior reversible encephalopathy syndrome is a clinical-radiological characterized by decreased level of consciousness, seizures, and visual disturbances, as well as radiologically ras brain edema, predominantly in parieto-occipital white matter regions. There are many situations that can trigger the disorder, including the administration of immunosuppressants, chemotherapy agents, hypertensive disorders, and sepsis. The case is described of a patient diagnosed with stage IV prostate adenocarcinoma, receiving chemotherapy, andundergoing a posterior reversible encephalopathy syndrome after surgery for resection of brain metastasis. PMID:25866131

  11. [Research advances of posterior reversible encephalopathy syndrome in children].

    PubMed

    Liu, Jing; Qin, Jiong

    2016-08-01

    Posterior reversible encephalopathy syndrome (PRES) is a clinico-neuroradiological entity affecting the posterior brain, i.e. occipital and parietal lobes. The syndrome are characterized by headaches, altered mental status, seizures, and visual disturbances. Although the pathogenesis remains unclear, endothelial dysfunction may be a key factor. The basic disease may play a crucial role in the incidence of PRES. In most cases, PRES resolves spontaneously and patients show both clinical and radiological improvements. In severe forms, PRES might cause substantial morbidity with sequel and even mortality, as a result of acute hemorrhage or massive posterior fossa edema causing obstructive hydrocephalus or brainstem compression. Early identification, active and appropriate treatment is very important. PMID:27530801

  12. Posterior reversible encephalopathy syndrome with neurological sequelae - a case report.

    PubMed

    Nesteruk, Marta; Kurdyła, Anna; Nesteruk, Tomasz; Dorobek, Małgorzata

    2016-04-01

    Posterior reversible encephalopathy syndrome (PRES) is a set of neurological symptoms including impaired consciousness, cognitive disorders, seizures, blurred vision, dizziness and headache. The symptoms are closely related to the location of pathological changes in the brain; bilateral occipitto-parietal region is most often affected. Both focal neurological symptoms and encephalopathy are usually transient. We present the case of 64-year-old woman with PRES. She suffered from many internal diseases and was admitted to the hospital due to impaired consciousness, speech disorders, balance disorders. Significant neurological deterioration was observed within several days from the onset. Differential diagnosis included stroke and viral neuroinfection (cytosis 23 cells /ul, protein level of 93 mg/dl); magnetic resonance examination revealed lesions typical for posterior reversible encephalopathy.After 6 weeks of hospitalization patient condition improved, but did not restore to the premorbid state. The patient was discharged with generalized cognitive impairment. PMID:27137827

  13. Rapidly reversible visual loss in posterior reversible encephalopathy syndrome: An ophthalmologist's enigma.

    PubMed

    Sachdeva, Virender; Garg, Ravi; Pathengay, Avinash; Chandrasekharan, Anjali; Kekunnaya, Ramesh

    2015-01-01

    Posterior reversible encephalopathy Syndrome (PRES) may present with a sudden onset reversible visual loss under special visual conditions. Such patients' may initially be misdiagnosed as Malingering. Ophthalmologists may be the first physicians to be confronted by such patients. Hence, a knowledge of this condition is vital to diagnosis and management of such conditions. PMID:26903736

  14. Delayed reversible posterior encephalopathy syndrome following chemotherapy with oxaliplatin.

    PubMed

    Sharief, Ubaidullah; Perry, David J

    2009-07-01

    Reversible posterior leukoencephalopathy (RPLS), also known as posterior reversible encephalopathy syndrome, is characterized by magnetic resonance imaging (MRI) findings of reversible vasogenic subcortical edema without infarction. The clinical presentation is usually nonspecific and typically involves global encephalopathy, seizures, headache, or visual symptoms. MRI of the brain is essential to the diagnosis of RPLS. Typical findings of RPLS include high-intensity signal on T2-weighted images predominantly in the posterior lobes of the brain that is caused by subcortical white matter vasogenic edema. Fluid-attenuated inversion recovery (FLAIR) sequences on MRI improve sensitivity and detect subtle peripheral lesions. This clinical radiographic syndrome has been described in a number of medical conditions, with hypertensive encephalopathy, eclampsia, and the use of immunosuppressant drugs (most notably calcineurin inhibitors) being the most common. It has occasionally been reported with cisplatin and rarely with carboplatin. Its occurrence with oxaliplatin is very unusual. An extensive literature search including PUBMED and direct contact with the drug manufacturer yielded only 2 known case reports. Herein, we describe a case that had classic clinical and radiologic features of RPLS. We also briefly describe 2 other patients who have been described to have RPLS with oxaliplatin in the literature. PMID:19632931

  15. Parainfluenza virus infection associated with posterior reversible encephalopathy syndrome: a case report

    PubMed Central

    2012-01-01

    Introduction Posterior reversible encephalopathy syndrome is a clinical and radiological entity. The most accepted theory of posterior reversible encephalopathy syndrome is a loss of autoregulation in cerebral blood flow with a subsequent increase in vascular permeability and leakage of blood plasma and erythrocytes, producing vasogenic edema. In infection-associated posterior reversible encephalopathy syndrome, a clinical pattern consistent with systemic inflammatory response syndrome develops. Parainfluenza virus has not been reported in the medical literature to be associated with posterior reversible encephalopathy syndrome. Case presentation We report herein the case of a 54-year-old Caucasian woman with posterior reversible encephalopathy syndrome associated with parainfluenza virus infection who presented with generalized headache, blurring of vision, new-onset seizure and flu-like symptoms. Conclusion Infection-associated posterior reversible encephalopathy syndrome as well as hypertension-associated posterior reversible encephalopathy syndrome favor the contribution of endothelial dysfunction to the pathophysiology of this clinicoradiological syndrome. In view of the reversible nature of this clinical entity, it is important that all physicians are well aware of posterior reversible encephalopathy syndrome in patients presenting with headache and seizure activity. A detailed clinical assessment leading to the recognition of precipitant factors in posterior reversible encephalopathy syndrome is paramount. PMID:22448715

  16. [Posterior Reversible Encephalopathy Syndrome Associated with Cancer Therapy].

    PubMed

    Mitsuya, Koichi; Nakasu, Yoko; Hayashi, Nakamasa; Yasui, Hirofumi; Ikeda, Takashi; Kuji, Shiho; Onozawa, Yusuke; Endo, Masahiro

    2016-03-01

    Posterior reversible encephalopathy syndrome(PRES)is a subacute neurological syndrome typically manifesting with headache, cortical blindness, and seizures. This syndrome is associated with risk factors such as malignant hypertension, eclampsia, and renal failure. Numerous case reports depict its occurrence in cancer patients. The direct causal mechanisms of PRES in cancer patients have not yet been identified. Cytotoxic chemotherapy may cause direct endothelial damage, which would impact the blood brain barrier. Angiogenesis inhibitors also cause elevation in blood pressure;this is significant, because PRES onset may be solely related to hypertension. An increased number of case reports involving new molecular targeted agent suggests that incidence of PRES as an oncological emergency may increase in the future. PMID:26965062

  17. The posterior reversible encephalopathy syndrome in HIV infection

    PubMed Central

    Nightingale, Sam; Wood, Chris; Ainsworth, Jonathan

    2012-01-01

    Posterior reversible encephalopathy syndrome (PRES) is often associated with hypertension, however recent advances in the understanding of this condition have shown that endothelial dysfunction is responsible for much of the pathogenesis and the condition can occur in the absence of hypertension. This case describes a 32-year-old lady with untreated HIV infection who developed PRES at a normal blood pressure and without opportunistic infection or other conditions known to precipitate PRES. HIV, particularly when untreated, is associated with endothelial dysfunction and this may have been sufficient to cause PRES in this patient. To our knowledge this is the first case to describe PRES in HIV without uncontrolled hypertension, sepsis or other precipitating cause. PMID:22736775

  18. Posterior Reversible Encephalopathy Syndrome (PRES) After Acute Pancreatitis

    PubMed Central

    Murphy, Tara; Al-Sharief, Khalid; Sethi, Vineeta; Ranger, Gurpreet S.

    2015-01-01

    Posterior reversible encephalopathy syndrome (PRES) is an unusual condition typified by acute visual impairment caused by sudden, marked parieto-occipital vasogenic edema. Thought to be inflammatory in origin, it has been described in patients undergoing chemotherapy, with autoimmune disease, and in some infections. We report a case of PRES that occurred one week after an episode of acute pancreatitis in an otherwise healthy 40-year-old female. There was progressive visual impairment over a 24-hour period with almost complete visual loss, with characteristic findings on magnetic resonance imaging. After treatment with steroids, the visual loss recovered. Clinicians should retain an index of suspicion of this rare condition in patients with visual impairment after acute pancreatitis. PMID:26759673

  19. Posterior reversible encephalopathy syndrome: another manifestation of CNS SLE?

    PubMed

    Ishimori, M L; Pressman, B D; Wallace, D J; Weisman, M H

    2007-01-01

    A variety of neuropsychiatric findings may complicate systemic lupus erythematosus (SLE) and pose diagnostic and therapeutic dilemmas. We describe the clinical and radiographic features of posterior reversible encephalopathy syndrome (PRES) and distinguish PRES from other conditions seen in SLE. Patient charts and magnetic resonance imaging (MRI) findings of four patients with SLE on immunosuppressive therapy with acute or subacute neurologic changes initially suggesting cerebritis or stroke were reviewed. The English language literature was reviewed using the Medline databases from 1996-2006 for other reports of PRES with SLE. Literature review yielded 26 other SLE cases reported with PRES. SLE patients with PRES were more commonly on immunosuppressive drugs, had episodes of relative hypertension, and had renal involvement. Characteristic findings are seen on MRI, which differentiate PRES from other CNS complications of SLE. Clinical and radiographic resolution of abnormalities within 1-4 weeks is typically seen. PRES has been increasingly recognized. Reversible changes are found on brain MRI accompanied by sometimes dramatic signs and symptoms. The therapeutic implications for separating PRES from stroke or cerebritis are important. We propose that PRES should be considered in the differential diagnosis in SLE patients with new-onset neurologic signs and symptoms. PMID:17664235

  20. Posterior reversible encephalopathy syndrome in leukemic children: a sensitive issue.

    PubMed

    Kridis, Wala Ben; Mdhaffer, Moez; Hentati, Yosr; Kammoun, Fatma; Milad, Abir; Haddar, Sondes; Mahfoudh, Khaireddine Ben; Triki, Chahinez; Elloumi, Moez

    2015-01-01

    Posterior reversible encephalopathy syndrome (PRES) is an acute central nervous system disorder characterized by reversible brain vasogenic edema. We report here a new case of a nine-year-old boy with B-cell acute lymphoblastic leukemia (B-ALL) who developed PRES secondary to induction chemotherapy including dexamethasone (dexamethasone®), vincristine (oncovin(®)), daunorubicin (adriblastine(®)) and intrathecal injection. Cerebral magnetic resonance imaging (MRI) showed high signal intensity on T2 at cortical and sub cortical region of parieto-frontal and parieto-occipital lobes. The patient was put under sodium valproate (depakine(®)) and we decided to continue dexamethasone (dexamethasone(®)) and daunorubicin (adriblastine(®)) injection. The MRI, after four weeks, was normal. So, we resumed vincristine (oncovin(®)) and we started L-asparaginase injections. Then, the outcome was favorable. The treatment of PRES is based on the withdrawal of the triggering factor to avoid the risk of irreversible lesions. But, due to the severity of leukemia the discontinuation of chemotherapy is difficult because of the risk of disease progression. PMID:24919742

  1. Posterior Reversible Encephalopathy Syndrome in Patients With Cancer

    PubMed Central

    Singer, Samuel; Grommes, Christian; Reiner, Anne S.; Rosenblum, Marc K.

    2015-01-01

    Background. Posterior reversible encephalopathy syndrome (PRES) is characterized by neurologic symptoms with typical lesions on neuroimaging and may be associated with chemotherapy and immunosuppressive agents used in patients with cancer. We described the spectrum of PRES at a major cancer center. Methods. We reviewed charts of adults with PRES between 2005 and 2011 at Memorial Sloan Kettering Cancer Center for clinical information and outcome. Results. We identified 21 women (68%) and 10 men (median cohort age: 58 years). Solid tumors (n = 22, 71%) were more common than hematologic (n = 8) or primary brain malignancies (n = 1). Prior brain irradiation (16%) and central nervous system metastases (10%) were uncommon. There were 55% who received chemotherapy or targeted therapy within the month preceding PRES, including 6 patients who received bevacizumab; PRES followed allogeneic stem cell transplantation in 5 (16%). Presenting symptoms included confusion (71%), seizure (58%), and headache (48%). Maximum systolic and diastolic blood pressures were similar among patients grouped by cancer type, chemotherapy or bevacizumab use, and atypical imaging. Moreover, 37% of patients with both magnetic resonance imaging (MRI) and computed tomography (CT) had normal CT concurrent with PRES on MRI, and 84% returned to neurologic baseline at a median of 7.5 days (range: 1–167 days) from onset. Successful anticonvulsant taper was achieved in 51%. Chemotherapy rechallenge was attempted in 41% without recurrent PRES. Autopsy revealed nonspecific changes isolated to radiographically affected areas in one of two patients. Conclusion. Recent chemotherapy, particularly bevacizumab, is common in cancer patients with PRES. Clinical and radiographic presentations may vary; MRI appears more sensitive than CT. Anticonvulsant taper and chemotherapy rechallenge is often possible. Implications for Practice: Posterior reversible encephalopathy syndrome is characterized by neurologic symptoms

  2. Primary brain tumors and posterior reversible encephalopathy syndrome

    PubMed Central

    Kamiya-Matsuoka, Carlos; Cachia, David; Olar, Adriana; Armstrong, Terri S.; Gilbert, Mark R.

    2014-01-01

    Background Posterior reversible encephalopathy syndrome (PRES) is a neurotoxic encephalopathic state associated with reversible cerebral vasogenic edema. It is an increasingly recognized occurrence in the oncology population. However, it is very uncommon in patients with primary brain tumors (PBTs). The aim of this study was to analyze the clinicoradiological features and report the clinical outcomes of PRES in PBT patients. Methods We identified 4 cases with PBT who developed PRES at MD Anderson Cancer Center (MDACC) between 2012 and 2014. Clinical and radiological data were abstracted from their records. In addition, we also solicited 8 cases from the literature. Results The median age at PRES onset was 19 years, male-to-female ratio was 1:1, and the syndrome occurred in patients with ependymoma (n = 4), glioblastoma (n = 3), diffuse intrinsic pontine glioma (DIPG; n = 3), juvenile pilocytic astrocytoma (n = 1), and atypical meningioma (n = 1). Two glioblastomas and 2 DIPG cases received bevacizumab and vandetanib before the onset of symptoms, respectively. The most common clinical presentation was seizures (n = 7). Three MDACC patients recovered completely in 3–4 weeks after the onset of symptoms. One patient died due to active cancer and several comorbidities including PRES. Conclusions Hypertension seems to be the most important coexisting risk factor for development of PRES; however, the potential effects of chemotherapeutic agents in the pathogenesis of PRES should also be examined. The clinicoradiological course of PRES in PBT patients did not vary from the classical descriptions of PRES found in other causes. PRES must be considered as part of the differential diagnosis in patients with PBTs presenting with seizures or acute encephalopathy. PMID:26034631

  3. Posterior reversible encephalopathy syndrome (PRES) and hypomagnesemia: A frequent association?

    PubMed

    Chardain, A; Mesnage, V; Alamowitch, S; Bourdain, F; Crozier, S; Lenglet, T; Psimaras, D; Demeret, S; Graveleau, P; Hoang-Xuan, K; Levy, R

    2016-01-01

    Posterior reversible encephalopathy syndrome (PRES) is a serious neurological condition encountered in various medical fields. Pathophysiological factor(s) common to PRES cases of apparently unrelated etiologies are yet to be found. Based on the hypothesis that hypomagnesemia might participate in the cascade leading to PRES, our study sought to verify whether hypomagnesemia is frequently associated with PRES regardless of etiology. From a retrospective study of a cohort of 57 patients presenting with PRES of different etiologies, presented here are the findings of 19 patients with available serum magnesium levels (SMLs) during PRES. In the acute phase of PRES, hypomagnesemia was present in all 19 patients in spite of differences in etiology (including immunosuppressive drugs, hypertensive encephalopathy, eclampsia, systemic lupus erythematosus, iatrogenic etiology and unknown). SMLs were within normal ranges prior to PRES and below normal ranges during the first 48h of PRES, with a significant decrease in SMLs during the acute phase. In this retrospective study, constant hypomagnesemia was observed during the acute phase of PRES regardless of its etiology. These results now require larger studies to assess the particular importance of acute hypomagnesemia in PRES and especially the possible need to treat PRES with magnesium sulfate. PMID:27371132

  4. THE DIAGNOSTIC AND MANAGEMENT CHALLENGES FOR POSTERIOR REVERSIBLE LEUCOENCEPHALOPATHY SYNDROME.

    PubMed

    Çoban, Eda Kiliç; Gez, Sedat; Kara, Batuhan; Soysal, Aysun

    2015-11-30

    Posterior reversible encephalopathy syndrome (PRES) is a clinicoradiological entity characterized by epileptic seizures, headaches, altered mental status and focal neurological signs. Hypertension is the second most common condition associated with PRES. The 50-year-old-male patient with, right-sided hemiparesis and speech disturbances admitted to our clinic. His blood pressure at the emergency service was 220/140 mmHg. A left putaminal hematoma was seen in his CT and MRI. In his brain MRI, FLAIR and T2 -weighted sequences showed bilateral symmetric diffuse hyperintensities in the brain stem, basal ganglia, and occipital, parietal, frontal, and temporal lobes. After the intense antihypertensive drug treatment, his blood pressure came to normal limits within a week. During his hospitalisation he had a recurrent speech disturbance lasting an hour. His electroencephalography was normal. In his repeated diffusion weighted MRI, an acute lacunary infarct was seen on right centrum semiovale. Two months later, the control MRI showed only the previous lacuner infarcts and the chronic putaminal hematoma. We presented a case developping either a cerebral hemorrhage or a lacunar infarction due to PRES. The main reason of the following complications of the disease was delayed diagnosis. Uncontrolled hypertension was guilted for the events. PMID:26821517

  5. Posterior reversible encephalopathy syndrome (PRES): electroencephalographic findings and seizure patterns.

    PubMed

    Kastrup, Oliver; Gerwig, Markus; Frings, Markus; Diener, Hans-Christoph

    2012-07-01

    To better describe seizure type, frequency, and electroencephalographic (EEG) findings in posterior reversible encephalopathy syndrome (PRES) and correlate these data with clinical and magnetic resonance imaging (MRI) data, we retrospectively assessed medical charts and EEG studies of patients with PRES treated between 2004 and 2011. Data collected included patients' underlying pathology, lesion distribution by MRI, seizure type and frequency, EEG pathologic background activity, focal pathology, and epileptogenic activity. Thirty-eight of 49 adults with PRES suffered from seizures; 17 underwent EEG and were included in the analysis. Perpetuating factors were similar to those reported in the literature. In 15 of 17 patients, MRI showed widespread involvement rather than purely occipital lesions. Nine patients had subcortical and cortical involvement. Seizures were single short grand mal (GM) in 11, serial GM in 2, recurrent GM in 2, and additional focal seizures in 2. No seizures were noted beyond the first day. After discontinuation of antiepileptic medication, no patients experienced seizure recurrence during 6-month follow-up. EEG showed diffuse theta/delta slowing in 13 patients and epileptogenic activity with focal sharp-wave and periodic lateralizing epileptiform discharges in 2 patients. Seizures in PRES are most commonly single GM and are usually of limited duration. EEG shows variable theta/delta slowing. Focal EEG pathology is seen in patients with focal seizures. Seizures occur early after disease onset and terminate spontaneously or under therapy during the first 24 h. Seizure recurrence beyond 24 h and chronic epilepsy were not seen. Seizures in PRES are frequent but appear to be uncomplicated and do not herald worse prognosis. EEG is helpful in evaluating the degree of encephalopathy and monitoring epileptic activity. Long-term antiepileptic medication does not appear to be warranted. PMID:22189837

  6. Posterior Reversible Encephalopathy Syndrome Occurring After Uterine Artery Embolization for Uterine Myoma

    SciTech Connect

    Suzuki, Satoshi Tanigawa, Noboru; Kariya, Syuji; Komemushi, Atsushi; Kojima, Hiroyuki; Tokuda, Takanori; Kishimoto, Masanobu; Tomino, Atsutoshi; Fujioka, Masayuki; Kitazawa, Yasuhide; Sawada, Satoshi

    2011-02-15

    This case report describes posterior reversible encephalopathy syndrome (PRES) occurring after uterine artery embolization (UAE) for uterine myoma. This is the first report of PRES occurring after uterine vascular radiologic intervention. The mechanism by which UAE induced PRES is unclear.

  7. Transient Global Amnesia with Reversible White Matter Lesions: A Variant of Posterior Reversible Encephalopathy Syndrome?

    PubMed

    Nakamizo, Tomoki; Tsuzuki, Ippei; Koide, Takashi

    2015-01-01

    Transient global amnesia (TGA) is a self-limited disease characterized by isolated amnesia, which resolves within 24 h. In contrast, posterior reversible encephalopathy syndrome (PRES) is a potentially life-threatening disease that usually presents with seizures, altered mental status, headache, and visual disturbances. It is characterized by reversible vasogenic edema that predominantly involves the parieto-occipital subcortical white matter as shown by neuroimaging studies. To date, there have been no reported cases of PRES with a clinical course resembling TGA. Here we report the case of a 58-year-old woman who presented with isolated amnesia and headache. On admission, her blood pressure was 187/100 mmHg. She had complete anterograde amnesia and slight retrograde amnesia without other neurological findings. After the treatment of her hypertension, the amnesia resolved within 24 h. Although the initial magnetic resonance image (MRI) was almost normal, the fluid attenuation inversion recovery (FLAIR) images of the MRI on the next day revealed several small foci of high intensity areas in the fronto-parieto-occipital subcortical white matter, presumed to be vasogenic edema in PRES. The lesions disappeared one month later. This case suggests that PRES can mimic the clinical course of TGA. PRES should be considered in the differential diagnosis for TGA. PMID:26697246

  8. Posterior reversible encephalopathy syndrome is not associated with mutations in aquaporin-4.

    PubMed

    Matiello, Marcelo; Muralidharan, Rajanandini; Sun, David; Rabinstein, Alejandro A; Weinshenker, Brian G

    2015-08-01

    Posterior reversible encephalopathy syndrome (PRES) is characterized by acute reversible subcortical vasogenic edema that is typically bilateral and self-limiting. It preferentially affects posterior regions of the brain. Clinical manifestations include encephalopathy, seizures, headache, and cortical blindness. PRES may be precipitated by hypertensive crises such as eclampsia and by immunosuppressive agents. The pathophysiology of PRES is incompletely understood. Disordered cerebral autoregulation leading to protein and fluid extravasation is thought to be important.(1) Other theories implicate endothelial dysfunction or vasospasm.(2). PMID:27066556

  9. [Posterior reversible encephalopathy in a girl with systemic lupus erythematosus: Report of a case].

    PubMed

    Marín, Gustavo R

    2015-10-01

    Posterior reversible encephalopathy is a rare disease in children. Clinical manifestations include headache, seizures, visual disturbances and altered consciousness associated with typical magnetic resonance images of the nervous system. The syndrome usually manifests in patients with eclampsia, solid organ transplantation, haematologic, renal and autoimmune diseases among other less common causes and it is often triggered after a hypertensive crisis or use of immunosuppressive drugs. Less common pathogenic factors as blood transfusion, use of immunoglobulins or an underlying infection can be associated. In this case a girl with systemic lupus erythematosus and exposed to multiple etiopathogenic factors developed posterior reversible encephalopathy. PMID:26294160

  10. Blood transfusion in sickle cell disease leading to posterior reversible encephalopathy syndrome (PRES).

    PubMed

    Raj, Shashi; Killinger, James; Overby, Philip

    2013-10-01

    Children with sickle cell disease have a very high risk of lifelong neurologic morbidity and mortality. Cerebrovascular accidents are a known complication in children with sickle cell disease. Posterior reversible encephalopathy syndrome is a constellation of acute neurologic findings increasingly recognized in pediatric critical care population with evidence of vasogenic edema on brain imaging possibly due to cerebral vascular endothelial cell dysfunction. This report, for the first time, describes a young adult with sickle cell disease who developed posterior reversible encephalopathy syndrome following blood transfusion. PMID:22899796

  11. Posterior reversible encephalopathy syndrome with spinal cord involvement (PRES-SCI): A case report.

    PubMed

    Khokhar, Harsh Vardhan; Choudhary, Pradeep; Saxena, Sangeeta; Arif, Mohamed

    2016-01-01

    Posterior reversible encephalopathy syndrome with spinal cord involvement (PRES-SCI) is a recently described entity with a handful of cases reported in literature. We describe a case of PRES in setting of Henoch-Schönlein purpura (HSP) with involvement of brain stem and spinal cord. PMID:27011648

  12. Good outcome after posterior reversible encephalopathy syndrome (PRES) despite elevated cerebral lactate: a case report

    PubMed Central

    Kondziella, Daniel; Danielsen, Else R; Thomsen, Carsten

    2015-01-01

    Posterior reversible encephalopathy syndrome (PRES) may cause irreversible brain damage. The diagnosis is confirmed by magnetic resonance imaging (MRI), where vasogenic edema may be seen especially in the posterior parts of the brain. MR spectroscopy (MRS) may be included to help predict the outcome by measuring selected metabolites for instance lactate. Usually lactate is immeasurable in brain tissue, but elevates in cases of hypoxia, and it has been associated with poor outcome. We report a case of a patient with eclampsia and PRES, who had elevated lactate initially, but complete remission clinically and on MRI. PMID:26331088

  13. Recurarization in a successfully managed case of posterior reversible encephalopathy syndrome (PRES) for emergency caesarean section.

    PubMed

    Parikh, Suchita; Tavri, Snehlata; Mohite, Shubha

    2016-01-01

    Posterior reversible encephalopathy syndrome (PRES) is a clinicoradiologic syndrome of headache, visual changes, altered mental status and seizures with radiologic findings of posterior cerebral white matter edema. It is seen in hypertensive encephalopathy, renal failure, and autoimmune disorders or in patients on immunosuppressants. We report a case of 24-year-old primigravida who presented at term with sudden onset hypertension, neurological deficits, and an episode of the visual blackout. Magnetic resonance imaging showed features suggestive of PRES. She was posted for emergency lower segment cesarean section. General anesthesia was administered and blood pressure managed with antihypertensives. Postoperatively, she developed acute respiratory depression after prophylactic administration of injection magnesium sulfate. This case highlights that good clinical acumen along with early neuroimaging helps in prompt diagnosis, treatment and prevention of long-term neurological sequelae in PRES and the anesthetic implications of administering magnesium sulfate in the immediate post neuromuscular block reversal phase. PMID:27212776

  14. Recurarization in a successfully managed case of posterior reversible encephalopathy syndrome (PRES) for emergency caesarean section

    PubMed Central

    Parikh, Suchita; Tavri, Snehlata; Mohite, Shubha

    2016-01-01

    Posterior reversible encephalopathy syndrome (PRES) is a clinicoradiologic syndrome of headache, visual changes, altered mental status and seizures with radiologic findings of posterior cerebral white matter edema. It is seen in hypertensive encephalopathy, renal failure, and autoimmune disorders or in patients on immunosuppressants. We report a case of 24-year-old primigravida who presented at term with sudden onset hypertension, neurological deficits, and an episode of the visual blackout. Magnetic resonance imaging showed features suggestive of PRES. She was posted for emergency lower segment cesarean section. General anesthesia was administered and blood pressure managed with antihypertensives. Postoperatively, she developed acute respiratory depression after prophylactic administration of injection magnesium sulfate. This case highlights that good clinical acumen along with early neuroimaging helps in prompt diagnosis, treatment and prevention of long-term neurological sequelae in PRES and the anesthetic implications of administering magnesium sulfate in the immediate post neuromuscular block reversal phase. PMID:27212776

  15. Reversible posterior leukoencephalopathy associated with chronic graft-versus-host disease: A case report

    PubMed Central

    YU, JINBEI; SUN, LICHAO; LIN, WEIHONG

    2016-01-01

    The present study describes the clinical manifestations, magnetic resonance imaging (MRI) features and treatments of a 22-year-old male patient diagnosed with reversible posterior leukoencephalopathy syndrome (RPLS) associated with graft-versus-host disease (GVHD) 7 months after a haploid hematopoietic stem cell transplantation. The patient was admitted to hospital after falling unconscious. Head MRI demonstrated abnormal signals in the bilateral, frontal, parietal, temporal and occipital lobes, consistent with reversible posterior leukoencephalopathy syndrome (RPLS). Based on a detailed diagnosis, the response to treatment and follow-up, it was concluded that RPLS was closely associated with chronic graft-versus-host disease in the patient. The present case report is described in order to increase the awareness of RPLS. PMID:27284340

  16. Reversible posterior leukoencephalopathy in a venomous snake (Bothrops asper) bite victim.

    PubMed

    Delgado, Miguel E; Del Brutto, Oscar H

    2012-03-01

    An 18-year-old man developed posterior reversible leukoencephalopaty after being bitten by a venomous snake (Bothrops asper). It is possible that this previously unrecognized neurological complication of snake bite envenoming occurred as the result of endothelial dysfunction induced by the venom of the offending snake. This pathogenetic mechanism has also been implicated as the cause of cerebral infarctions in snake bite victims. Alternatively, the leukoencephalopathy might have been a complication of antivenom therapy. PMID:22403325

  17. Late postpartum eclampsia complicated with posterior reversible encephalopathy syndrome: a case report and a literature review

    PubMed Central

    Zhang, Lihong; Wang, Yacong; Shi, Liang; Cao, Jianhui

    2015-01-01

    Posterior reversible encephalopathy syndrome (PRES) is a rare but serious clinical-neuroradiological entity characterized by headache, vomiting, visual disturbances, altered mental status, seizures, and unconsciousness associated with the characteristic imaging findings including sub-cortical vasogenic edema at the bilateral parietal and occipital lobes. We describe a case of 28-year-old PRES patient secondary to delayed maternal postpartum eclampsia. This patient was not initially diagnosed with pre-eclampsia and PRES. The diagnosis was established after magnetic resonance imaging. After treatment this patient’s PRES resolved. Early diagnosis and treatment are the keys to reverse PRES. A literature review for PRES is provided in this report. PMID:26807372

  18. Posterior reversible encephalopathy syndrome in pediatric acute leukemia: Case series and literature review

    PubMed Central

    Appachu, M. Sandhya; Purohit, Samit; Lakshmaiah, K. C.; Kumari, B.S. Aruna; Appaji, L.

    2014-01-01

    Posterior reversible encephalopathy syndrome (PRES) is a neurotoxic state coupled with a unique radio imaging appearance. We describe this rare, mostly reversible condition in five cases undergoing similar treatment under preset protocol (MCP-841) for acute lymphoblastic leukemia (ALL) at our centre. Hypertension is a well-known adverse effect of high-dose corticosteroid therapy primarily mediated by its effects on the mineralocorticoid receptor especially in pediatric population and we hypothesize that this may be the etiology of PRES in two of these patients. PMID:25006290

  19. Improvement of the Rotation Arch of the Posterior Interosseous Pedicle Flap Preserving Both Reverse Posterior and Anterior Interosseous Vascular Sources

    PubMed Central

    Tiengo, Cesare; Lombardi, Matteo; Bassetto, Franco

    2016-01-01

    Purpose: The reverse posterior interosseous artery flap has several advantages, not sacrificing any major blood vessel, but its relatively short pedicle limits the use to cover defects up to the metacarpophalangeal joint. Our purpose is to demonstrate that the ligature of the anterior interosseous artery (AIA), proximal to the communicating branch with the posterior interosseous artery, leads to an improved flap rotation arch, preserving both vascular sources. Methods: Sixteen fresh cadavers with latex perfusion were analyzed before and after our technique of elongation, and the so-obtained measures were standardized in “percentage of elongation of the pedicle.” Eight patient with the loss of substance at the dorsal aspect of the hand have been treated with this technique, and results were evaluated in terms of flap survival and complication rates. Results: The medium length of the pedicle in the normal flap was 10.8 cm, and after the section of the AIA, the medium length of the pedicle was 13.6 cm with a medium increase of 2.8 cm. It means a medium increase of 24% of the length of the pedicle. In all patients treated, full coverage of the defect was obtained, and we did not experience major complications. Conclusions: This anatomical study supported by our clinical experience demonstrates that the use of the variant described above permits to reach more distal part of the hand without being afraid to stretch the pedicle because of the connection with the anastomotic arcades of the AIA at the wrist reducing the risk of ischemia of the flap. PMID:27536473

  20. Oxaliplatin-induced posterior reversible encephalopathy syndrome with isolated involvement of pons.

    PubMed

    Tang, Koay Hean

    2015-01-01

    Isolated pontine lesion can be caused by the posterior reversible encephalopathy syndrome (PRES). It does occur in the normotensive patient who is treated with oxaliplatin. We reported a case of 81-year-old Chinese man with metastatic colorectal carcinoma who was initially treated with capecitabine. No significant adverse effects were noted. However, the response to the treatment was poor. Subsequently, Xelox was given. He developed transient altered mental status. Oxaliplatin was thought to be the causative agent and was withheld. Magnetic resonance imaging brain revealed vasogenic edema in the pons that was reversible after 2 weeks, as well as complete resolution of clinical symptoms. Early identification of the reversible cause of isolated pontine lesion, such as chemo, triggered PRES is crucial to facilitate prompt treatment by removing the offending agent or reducing the dose. PMID:26881576

  1. A Rare Presentation of Lupus Nephritis Flare up with Posterior Reversible Leucoencephalopathy.

    PubMed

    Mani, S Hima; Shivaprasad, S M; Umesh, L

    2016-01-01

    Systemic lupus erythematosus (SLE) is associated with various neurologic or psychiatric abnormalities and Posterior Reversible Leuco Encephalopathy Syndrome (PRES) is very rare neurological manifestation in SLE. PRES is associated with various clinical manifestations, like, seizures, visual loss, headaches, vomiting altered mental status and rarely focal neurological deficits. Other predisposing condition associated with PRES is eclampsia, accelerated hypertension, uraemia, transplantation, autoimmune diseases and/or use of immunosuppressive drugs. It is important to recognise PRES since it is a potentially reversible. We describe an unusual case of PRES caused by uraemia during lupus flare up in a patient with biopsy proven class IV lupus nephritis who presented with features of asymmetrical quadriparesis which completely reversed after haemodialysis sessions and treating lupus flare up. In our case she presented with quadriparesis which is a rare presentation and hypertensive encephalopathy was not present. PMID:26894110

  2. An unusual case of posterior reversible encephalopathy syndrome in a patient being weaned from intrathecal morphine.

    PubMed

    Van Aalst, Jasper; Teernstra, Onno P; Weber, Wim E; Rijkers, Kim

    2016-01-01

    Posterior reversible encephalopathy syndrome (PRES) is a clinicoradiological entity based on clinical signs, including headache, visual abnormalities, and seizures, and radiological abnormalities mostly consisting of vasogenic brain edema predominantly in the posterior parietal-temporal-occipital regions. PRES typically develops in the setting of a significant " systemic process", including preeclampsia, transplantation, infection/sepsis/shock, autoimmune disease, and cancer chemotherapy, in which hypertension often plays an important role. We present a case of PRES in a 63-year-old female patient with an infected intrathecal morphine pump on a cocktail of antibiotics, morphine, clonidine, diazepam, and amitriptyline. It is the first PRES case in a chronic pain patient, which illustrates that PRES can occur in the absence of any of the established risk factors. We hypothesize it may have been caused by antibiotic treatment in our patient. PMID:27274314

  3. Atypical presentation of posterior reversible encephalopathy syndrome: Clinical and radiological characteristics in eclamptic patients.

    PubMed

    Aracki-Trenkić, Aleksandra; Stojanov, Dragan; Trenkić, Milan; Radovanović, Zoran; Ignjatović, Jelena; Ristić, Saša; Trenkić-Bozinović, Marija

    2016-08-01

    Posterior reversible encephalopathy syndrome (PRES) is an obstetric emergency frequently occurring in a pregnant or puerperal woman, manifested with an acute headache, consciousness impairment, seizures, and visual deficits and is associated with white matter changes predominantly affecting the posterior parietal and occipital lobes of the brain. Apart from the above-described typical location of the changes, the most common atypical location involves the brain stem and basal ganglia. Since magnetic resonance imaging (MRI) is more sensitive and specific imaging technique compared to computerized tomography, establishing the diagnosis and follow-up in patients with PRES is based mainly on MRI findings. It is particularly important not to exclude PRES as a possible diagnosis when we have the appropriate clinical presentation accompanied by the atypical radiological findings, since this clinical-radiological syndrome can often be manifested with an atypical MRI image. PMID:27322924

  4. Posterior Reversible Encephalopathy Syndrome in the Emergency Department: Case Series and Literature Review

    PubMed Central

    Thompson, Ryan J.; Sharp, Brian; Pothof, Jeffery; Hamedani, Azita

    2015-01-01

    Introduction Posterior Reversible Encephalopathy Syndrome (PRES) often has variable presentations and causes, with common radiographic features—namely posterior white matter changes on magnetic resonance (MRI). As MRI becomes a more frequently utilized imaging modality in the Emergency Department, PRES will become an entity that the Emergency Physician must be aware of and be able to diagnose. Case Report We report three cases of PRES, all of which presented to the emergency department of a single academic medical center over a short period of time, including a 53-year-old woman with only relative hypertension, a 69-year-old woman who ultimately died, and a 46-year-old woman who had a subsequent intraparenchymal hemorrhage. Conclusion PRES is likely much more common than previously thought and is a diagnosis that should be considered in a wide variety of emergency department patient presentations. PMID:25671001

  5. Reversible posterior leukoencephalopathy syndrome in childhood: report of nine cases and review of the literature.

    PubMed

    Gümüş, Hakan; Per, Hüseyin; Kumandaş, Sefer; Yikilmaz, Ali

    2010-04-01

    Reversible posterior leukoencephalopathy syndrome (RPLS) is recently described disorder with typical radiological findings in the posterior regions of the cerebral hemisphere and cerebellum. Its clinical symptoms include headache, decreased alertness, mental abnormalities, such as confusion, diminished spontaneity of speech, and changed behavior ranging from drowsiness to stupor, seizures, vomiting and abnormalities of visual perception like cortical blindness. RPLS is caused by various heterogeneous factors, the commonest being hypertension, followed by non-hypertensive causes such as eclampsia, renal diseases and immunosuppressive therapy. We presented nine patients with RPLS who had primary diagnoses such as acute post-streptococcal glomerulonephritis, idiopathic hypertension, the performing of intravenous immunoglobulin for infection with crescentic glomerulonephritis, erythrocyte transfusion for severe iron deficiency, L: -asparaginase treatment for acute lymphoblastic leukemia and performing of granulocyte-colony stimulating factor for ulcerative colitis due to neutropenia. Early recognition of RPLS as complication during different diseases and therapy in childhood may facilitate precise diagnosis and appropriate treatment. PMID:19809787

  6. An unusual case of posterior reversible encephalopathy syndrome in a patient being weaned from intrathecal morphine

    PubMed Central

    Van Aalst, Jasper; Teernstra, Onno P; Weber, Wim E; Rijkers, Kim

    2016-01-01

    Posterior reversible encephalopathy syndrome (PRES) is a clinicoradiological entity based on clinical signs, including headache, visual abnormalities, and seizures, and radiological abnormalities mostly consisting of vasogenic brain edema predominantly in the posterior parietal-temporal-occipital regions. PRES typically develops in the setting of a significant “ systemic process”, including preeclampsia, transplantation, infection/sepsis/shock, autoimmune disease, and cancer chemotherapy, in which hypertension often plays an important role. We present a case of PRES in a 63-year-old female patient with an infected intrathecal morphine pump on a cocktail of antibiotics, morphine, clonidine, diazepam, and amitriptyline. It is the first PRES case in a chronic pain patient, which illustrates that PRES can occur in the absence of any of the established risk factors. We hypothesize it may have been caused by antibiotic treatment in our patient. PMID:27274314

  7. Atypical presentation of posterior reversible encephalopathy syndrome: Clinical and radiological characteristics in eclamptic patients.

    PubMed

    Aracki-Trenkić, Aleksandra; Stojanov, Dragan; Trenkić, Milan; Radovanović, Zoran; Ignjatović, Jelena; Ristić, Saša; Trenkić-Bozinović, Marija

    2016-08-01

    Posterior reversible encephalopathy syndrome (PRES) is an obstetric emergency frequently occurring in a pregnant or puerperal woman, manifested with an acute headache, consciousness impairment, seizures, and visual deficits and is associated with white matter changes predominantly affecting the posterior parietal and occipital lobes of the brain. Apart from the above-described typical location of the changes, the most common atypical location involves the brain stem and basal ganglia. Since magnetic resonance imaging (MRI) is more sensitive and specific imaging technique compared to computerized tomography, establishing the diagnosis and follow-up in patients with PRES is based mainly on MRI findings. It is particularly important not to exclude PRES as a possible diagnosis when we have the appropriate clinical presentation accompanied by the atypical radiological findings, since this clinical-radiological syndrome can often be manifested with an atypical MRI image. PMID:27483175

  8. Posterior reversible encephalopathy syndrome in a child with Henoch-Schönlein purpura

    PubMed Central

    Sivrioglu, Ali Kemal; Incedayi, Mehmet; Mutlu, Hakan; Meral, Cihan

    2013-01-01

    Henoch-Schönlein purpura (HSP) is a small vessel vasculitis that affects the gastrointestinal and central nervous systems and the kidneys. The disease primarily affects children, but may occur in elderly children with allergic purpura and also in adults. Central nervous system involvement may be the first sign; however, it is rarely encountered. Posterior reversible encephalopathy syndrome (PRES) is a clinical syndrome of encephalopathy, headache, visual disturbance and seizures. Its radiological signs can be observed in grey and white matter at the posterior region of the cerebral hemispheres. HSP should be considered in children with PRES in the presence of rash, joint and gastrointestinal symptoms. We reported a 5-year-old patient who developed acute renal failure and PRES by reason of HSP. PMID:23946524

  9. Atypical presentation of posterior reversible encephalopathy syndrome: Clinical and radiological characteristics in eclamptic patients

    PubMed Central

    Aracki-Trenkić, Aleksandra; Stojanov, Dragan; Trenkić, Milan; Radovanović, Zoran; Ignjatović, Jelena; Ristić, Saša; Trenkić-Bozinović, Marija

    2016-01-01

    Posterior reversible encephalopathy syndrome (PRES) is an obstetric emergency frequently occurring in a pregnant or puerperal woman, manifested with an acute headache, consciousness impairment, seizures, and visual deficits and is associated with white matter changes predominantly affecting the posterior parietal and occipital lobes of the brain. Apart from the above-described typical location of the changes, the most common atypical location involves the brain stem and basal ganglia. Since magnetic resonance imaging (MRI) is more sensitive and specific imaging technique compared to computerized tomography, establishing the diagnosis and follow-up in patients with PRES is based mainly on MRI findings. It is particularly important not to exclude PRES as a possible diagnosis when we have the appropriate clinical presentation accompanied by the atypical radiological findings, since this clinical-radiological syndrome can often be manifested with an atypical MRI image.

  10. [A case of posterior reversible encephalopathy syndrome associated with coil embolization of a basilar apex aneurysm].

    PubMed

    Naito, Hiroyuki; Yamazaki, Yu; Takahashi, Tetsuya; Ochi, Kazuhide; Kiura, Yoshihiro; Matsumoto, Masayasu

    2013-01-01

    About three weeks after successful coil embolization of a basilar apex aneurysm, a 66-year-old woman developed occipital headaches. T2 and FLAIR MRI brain images demonstrated multiple new hyperintense lesions in the posterior circulation territory including cerebellum, right superior cerebellar peduncle, left thalamus and bilateral temporo-occipital lobes and she was subsequently hospitalized. Findings suggestive of other underlying disease were not observed, although an increased protein level was noted in cerebrospinal fluid (69 mg/dl). Headache and clinical findings improved approximately 12 weeks after coil embolization. MRI findings also showed improvement. These clinical and radiological findings made this patient a distinctive case of posterior reversible encephalopathy syndrome (PRES) associated with coil embolization suggesting that clinicians should be aware that PRES can present as comparatively mild symptoms several weeks after coil embolization. PMID:23892962

  11. Minimally symptomatic posterior reversible encephalopathy in Guillain-Barré syndrome

    PubMed Central

    Piccolo, Giovanni; Borutti, Giuseppina; Franciotta, Diego; Arbasino, Carla; Dallocchio, Carlo; Camana, Claudia; Gola, Giada; Egitto, Maria Grazia

    2015-01-01

    Summary Posterior reversible encephalopathy syndrome (PRES) is a rare occurrence in patients with Guillain-Barré syndrome (GBS). Two patients with neuroradiological evidence of PRES without central nervous system (CNS) symptoms were recently reported. We present the case of a GBS patient with minimal CNS symptoms and magnetic resonance imaging findings consistent with PRES. PRES in GBS might be an underestimated condition. It should be suspected in GBS patients in the presence of even mild CNS symptoms. A timely PRES diagnosis along with early correction of autonomic system dysfunction in GBS patients is recommended to prevent possible dangerous CNS complications. PMID:26214029

  12. Posterior reversible encephalopathy syndrome following sepsis in a Crohn’s disease patient: A case report

    PubMed Central

    Papaconstantinou, Ioannis; Mantzos, Dionysios S; Pantiora, Eirini; Tasoulis, Marios K; Vassilopoulou, Sofia; Mantzaris, Gerassimos

    2016-01-01

    Posterior reversible encephalopathy syndrome (PRES) is a clinico-ragiological syndrome presenting with neurological symptoms and characteristic radiologic findings. PRES occurs in the setting of various clinical conditions and requires prompt management of the causative factor for a full recovery. This is a case report of a Crohn’s disease patient who developed PRES syndrome during a complicated post-operative course. In the presence of multiple causative factors, sepsis was considered as the predominant one. After prompt management, the patient recovered with no permanent neurological damage. PMID:27099860

  13. Reversible Posterior Leukoencephalopathy Syndrome Associated with Treatment for Acute Exacerbation of Ulcerative Colitis.

    PubMed

    Kikuchi, Shinsuke; Orii, Fumika; Maemoto, Atsuo; Ashida, Toshifumi

    2016-01-01

    Reversible posterior leukoencephalopathy syndrome (RPLS) is a clinical syndrome of varying etiologies with similar neuroimaging findings. This is a case report of a 25-year-old woman who developed typical, neurological symptoms and magnetic resonance imaging abnormalities after treatment for the acute exacerbation of ulcerative colitis (UC), which included blood transfusion, the systemic administration of prednisolone, and the administration of metronidazole. It has been reported that these treatments may contribute to the development of RPLS. RPLS should therefore be considered in the differential diagnosis of UC patients who exhibit impaired consciousness, seizures or visual deficits during treatment. We report a rare case of RPLS in a patient with UC. PMID:26935366

  14. Posterior reversible encephalopathy syndrome following sepsis in a Crohn's disease patient: A case report.

    PubMed

    Papaconstantinou, Ioannis; Mantzos, Dionysios S; Pantiora, Eirini; Tasoulis, Marios K; Vassilopoulou, Sofia; Mantzaris, Gerassimos

    2016-04-16

    Posterior reversible encephalopathy syndrome (PRES) is a clinico-ragiological syndrome presenting with neurological symptoms and characteristic radiologic findings. PRES occurs in the setting of various clinical conditions and requires prompt management of the causative factor for a full recovery. This is a case report of a Crohn's disease patient who developed PRES syndrome during a complicated post-operative course. In the presence of multiple causative factors, sepsis was considered as the predominant one. After prompt management, the patient recovered with no permanent neurological damage. PMID:27099860

  15. Posterior Reversible Encephalopathy Syndrome and Subarachnoid Hemorrhage After Lumboperitoneal Shunt for Fulminant Idiopathic Intracranial Hypertension.

    PubMed

    Fok, Anthony; Chandra, Ronil V; Gutman, Matthew; Ligtermoet, Matthew; Seneviratne, Udaya; Kempster, Peter

    2016-06-01

    A 33-year-old woman presented with severe visual loss from fulminant idiopathic intracranial hypertension. Her lumbar puncture opening pressure was 97 cm H2O. Soon after lumboperitoneal shunt surgery, she had a generalized tonic-clonic seizure. Magnetic resonance imaging demonstrated frontal subarachnoid hemorrhage (SAH) and neuroimaging findings consistent with posterior reversible encephalopathy syndrome (PRES). We hypothesize that an abrupt drop in intracranial pressure after lumboperitoneal shunting led to maladjustment of cerebral vascular autoregulation, which caused SAH and PRES. PMID:26919070

  16. Acute Respiratory Distress Syndrome and Posterior Reversible Encephalopathy Syndrome following Rituximab Therapy.

    PubMed

    Wardrope, Katrina E; Manson, Lynn; Metcalfe, Wendy; Sullivan, Eoin D O

    2016-01-01

    The anti-CD20 monoclonal antibody rituximab is associated with rare but significant adverse events, notably posterior reversible encephalopathy syndrome (PRES) and acute respiratory distress syndrome (ARDS). We report a case of concomitant ARDS and PRES developing after rituximab therapy for treatment of cryoglobulinaemic vasculitis. There are 7 reported cases of PRES complicating rituximab use. PRES onset varied from immediate to 21 days after administration. All patients recovered completely, and rituximab was reintroduced in half of the cases. The occurrence of ARDS in association with rituximab is rarer. Only 3 confirmed cases exist, and ARDS may occur as a delayed reaction. PMID:27275457

  17. Posterior reversible encephalopathy syndrome in a hypertensive patient with renal failure.

    PubMed

    Aatif, T; El Farouki, M R; Benyahia, M

    2016-03-01

    Posterior reversible encephalopathy syndrome (PRES) is a clinical and neuroimaging entity characterized by headache, visual field deficits, changes in mentation and seizures, and by typical neuro-imaging features such as areas of sub-cortical edema, occasionally cortical, involving predominantly the occipital and parietal lobes of both hemispheres. Hypertension, uremia, immunosuppressive drugs neurotoxicity, preeclampsia or eclampsia, renal disease, and sepsis are the most common etiologies of PRES. Less common, it has been described in the setting of autoimmune disease. We report a case of PRES which was associated with hypertensive crisis in a patient with renal failure. Antihypertensive therapy and hemodialysis resulted in complete recovery. PMID:26997402

  18. Acute Respiratory Distress Syndrome and Posterior Reversible Encephalopathy Syndrome following Rituximab Therapy

    PubMed Central

    Wardrope, Katrina E.; Manson, Lynn; Metcalfe, Wendy; Sullivan, Eoin D. O

    2016-01-01

    The anti-CD20 monoclonal antibody rituximab is associated with rare but significant adverse events, notably posterior reversible encephalopathy syndrome (PRES) and acute respiratory distress syndrome (ARDS). We report a case of concomitant ARDS and PRES developing after rituximab therapy for treatment of cryoglobulinaemic vasculitis. There are 7 reported cases of PRES complicating rituximab use. PRES onset varied from immediate to 21 days after administration. All patients recovered completely, and rituximab was reintroduced in half of the cases. The occurrence of ARDS in association with rituximab is rarer. Only 3 confirmed cases exist, and ARDS may occur as a delayed reaction.

  19. Posterior reversible encephalopathy syndrome in patient of severe preeclampsia with Hellp syndrome immediate postpartum

    PubMed Central

    Babahabib, Moulay Abdellah; Abdillahi, Ibrahima; Kassidi, Farid; Kouach, Jaouad; Moussaoui, Driss; Dehayni, Mohammed

    2015-01-01

    Posterior reversible encephalopathy syndrome (PRES) is a rare clinico-neuroradiologic condition, not commonly reported in the literature. PRES is an uncommon complication of severe preeclampsia/eclampsia. We report the management of one patient with postpartum preeclampsia as an association of HELLP syndrome presenting with status-epileptics. Early diagnosis along with timely supportive therapy resulted in the successful management of this challenging case. Recent understanding on the pathophysiology of this uncommon condition is discussed. We highlight the importance to obstetricians, intensive-care physicians and anesthesiologists of recognizing such cases. PMID:26405496

  20. Posterior reversible encephalopathy syndrome in patient of severe preeclampsia with Hellp syndrome immediate postpartum.

    PubMed

    Babahabib, Moulay Abdellah; Abdillahi, Ibrahima; Kassidi, Farid; Kouach, Jaouad; Moussaoui, Driss; Dehayni, Mohammed

    2015-01-01

    Posterior reversible encephalopathy syndrome (PRES) is a rare clinico-neuroradiologic condition, not commonly reported in the literature. PRES is an uncommon complication of severe preeclampsia/eclampsia. We report the management of one patient with postpartum preeclampsia as an association of HELLP syndrome presenting with status-epileptics. Early diagnosis along with timely supportive therapy resulted in the successful management of this challenging case. Recent understanding on the pathophysiology of this uncommon condition is discussed. We highlight the importance to obstetricians, intensive-care physicians and anesthesiologists of recognizing such cases. PMID:26405496

  1. Posterior reversible encephalopathy syndrome with PLEDs-plus due to mesalamine

    PubMed Central

    Cherian, Ajith; Soumya, C. V.; Iype, Thomas; Mathew, Mini; Sandeep, P.; Thadam, Jessline K.; Chithra, P.

    2014-01-01

    A 32-year-old lady developed status epilepticus and acute visual loss while on mesalamine for Crohn's disease. Her clinical course and magnetic resonance imaging (MRI) were suggestive of posterior reversible encephalopathy syndrome (PRES). She had periodic lateralized epileptiform discharges plus (PLEDs-plus) on electroencephalogram (EEG), which responded to sodium valproate. Her vision improved from counting fingers at one-meter distance to 6/12. Though different cytotoxic drugs have been implicated as causative agents, this is the first case report of mesalamine-induced PRES. This case highlights the need for aggressive treatment of PLEDs-plus with EEG monitoring using a broad-spectrum antiepileptic drug like valproate, which has contributed to the rapid reversibility of vision in PRES subjects, and the need for a thorough drug history for etiological clues. PMID:24741259

  2. Posterior reversible encephalopathy syndrome: an acute manifestation of systemic lupus erythematous.

    PubMed

    Chan, Dexter Yak Seng; Ong, Yin Sheng

    2013-09-01

    Stroke mimickers are common, and they represent a diagnostic dilemma for clinicians. Many, like posterior reversible encephalopathy syndrome (PRES), are easily reversible. The manifestation of PRES is characterised by headaches, convulsions, altered mental functioning and blindness. In most cases, computed tomography of the brain will show hypodense lesions in the parieto-occpitial lobe, which only further confounds the physician. Although this syndrome is uncommon, prompt and accurate recognition allows early treatment, which has been shown to produce favourable outcomes. Herein, we report the case of a 54-year-old woman, who presented with PRES, as an acute manifestation of systemic lupus erythematous (SLE) and lupus nephritis. The patient was initially thought to be experiencing an ischaemic stroke, but the diagnosis was later changed. On management of her underlying condition, her symptoms resolved. PRES should be recognised as an acute emergency manifestation of SLE. It should not be mistaken for an ischaemic stroke as inappropriate treatment could have adverse outcomes. PMID:24068069

  3. Reversible posterior encephalopathy syndrome associated with late onset postpartum eclampsia: A case report

    PubMed Central

    Bo, Qi-Yu; Zhao, Xiu-He; Yang, Xue; Wang, Sheng-Jun

    2016-01-01

    Late onset postpartum eclampsia (LPE) is defined by its onset at >48 h after delivery. Reversible posterior encephalopathy syndrome (RPES) associated with LPE is uncommon, with the majority of RPES cases having a late postpartum onset within 4 weeks after childbirth. The present study reported the case of a 15-year old female presenting with convulsions that began 5 weeks after delivery. A magnetic resonance imaging scan of the brain revealed multiple lesions in the cortex, subcortical region and deep white matter of the bilateral cerebellum, and occipital, frontal and parietal lobes. The clinical manifestations and radiological abnormalities were readily resolved subsequent to antihypertension and anticonvulsion treatment. In conclusion, the present rare case indicates that LPE should be considered as a potential diagnosis even at 4 weeks after delivery. Furthermore, clinicians should familiarize with the reversible radioimaging features of RPES, since early recognition and adequate treatment are important to the outcome of patients. PMID:27602098

  4. Posterior Reversible Encephalopathy Syndrome due to High Dose Corticosteroids for an MS Relapse.

    PubMed

    Morrow, Sarah A; Rana, Robina; Lee, Donald; Paul, Terri; Mahon, Jeffrey L

    2015-01-01

    Increased blood pressure is a known adverse effect associated with corticosteroids but little is published regarding the risk with the high doses used in multiple sclerosis (MS). A 53-year-old female with known relapsing remitting MS presented with a new brainstem relapse. Standard of care treatment for an acute MS relapse, 1250 mg of oral prednisone for 5 days, was initiated. She developed an occipital headache and dizziness and felt generally unwell. These symptoms persisted after treatment was complete. On presentation to medical attention, her blood pressure was 199/110 mmHg, although she had no history of hypertension. MRI changes were consistent with posterior reversible encephalopathy syndrome (PRES), demonstrating abnormal T2 signal in both thalami, the posterior occipital and posterior parietal white matter with mild sulcal effacement. As her pressure normalized with medication, her symptoms resolved and the MRI changes improved. No secondary cause of hypertension was found. This is the first reported case of PRES secondary to high dose corticosteroid use for an MS relapse without a history of hypertension and with no other secondary cause of hypertension identified. This rare complication should be considered in MS patients presenting with a headache or other neurological symptoms during treatment for a relapse. PMID:26101676

  5. Posterior reversible encephalopathy syndrome: temporary visual loss after spinal deformity surgery.

    PubMed

    Kueper, Janina; Loftus, Michael L; Boachie-Adjei, Oheneba; Lebl, Darren

    2015-11-01

    Posterior reversible encephalopathy syndrome (PRES) is a rare cause of temporary postoperative visual loss (POVL) after spinal deformity surgery. We report on 2 patients diagnosed with PRES after spinal deformity surgery, who were closely examined postoperatively. A 78-year-old woman with severe disability due to degenerative lumbar spondylosis after laminectomy was treated with transpsoas lumbar interbody fusion from L1 to L4 and posterior spinal fusion from T10 to pelvis. She developed confusion and bilateral visual loss on postoperative day 7. A second patient, a 51-year-old woman with progressive pain and decompensation caused by adult scoliosis, was treated with posterior spinal fusion from T3 to pelvis and interbody fusion from L4 to S1 via a presacral interbody fusion approach. She developed bilateral visual loss on postoperative day 15. Both patients achieved a complete recovery of their vision after medical management of PRES. Timely diagnosis of PRES and prompt intervention allow for a good patient prognosis and complete recovery of eyesight. PMID:26566564

  6. [A case of posterior reversible encephalopathy syndrome associated with Takayasu's arteritis].

    PubMed

    Wakida, Kenji; Morita, Hiroyuki; Sakurai, Takeo; Nishida, Hiroshi

    2016-01-01

    A 75-year-old woman presented with a 4-month history of repetitive loss of consciousness, dizziness, and ear fullness. Fluid attenuation inversion recovery magnetic resonance imaging showed high-intensity areas in the right occipital lobe, both frontal lobes, and parietal lobes, and the patient was therefore admitted to our department for further examination. Neurologic findings included a positive Barré sign (right upper extremity), impaired tandem gait, and positive left-sided Babinski reflex. The patient was diagnosed with Takayasu's arteritis owing to a difference in blood pressure between the left and right upper extremity, weakened pulse in the left upper extremity, as well as thickened arterial wall, and delayed enhancement on a contrast-enhanced computed tomography image. The head magnetic resonance imaging findings disappeared within 4 months and the patient was diagnosed with posterior reversible encephalopathy syndrome. Posterior reversible encephalopathy syndrome associated with elderly female Takayasu's arteritis is rare. ; the present case therefore offers valuable information. PMID:26912227

  7. Tacrolimus-associated posterior reversible encephalopathy syndrome after solid organ transplantation.

    PubMed

    Wu, Qisi; Marescaux, Christian; Wolff, Valérie; Jeung, Mi-Young; Kessler, Romain; Lauer, Valérie; Chen, Yangmei

    2010-01-01

    Tacrolimus (TAC) is an immunosuppressant drug discovered in 1984 by Fujisawa Pharmaceutical Co., Ltd. This drug belongs to the group of calcineurin inhibitors, which has been proven highly effective in preventing acute rejection after transplantation of solid organs. However, neurotoxicity and nephrotoxicity are its major adverse effects. Posterior reversible encephalopathy syndrome (PRES) is the most severe and dramatic consequence of calcineurin inhibitor neurotoxicity. It was initially described by Hinchey et al. in 1996 [N Engl J Med 1996;334:494-450]. Patients typically present with altered mental status, headache, focal neurological deficits, visual disturbances, and seizures. Magnetic resonance imaging is the most sensitive imaging test to detect this. With the more deep-going studies done recently, we have learnt more about this entity. It was noted that this syndrome is frequently reversible, rarely limited to the posterior regions of the brain, and often located in gray matter and cortex as well as in white matter. Therefore, in this review, the focus is on the current understanding of clinical recognition, pathogenesis, neuroimaging and management of TAC-associated PRES after solid organ transplantation. PMID:20699617

  8. An intensive care approach to posterior reversible encephalopathy syndrome (PRES): An analysis of 7 cases

    PubMed Central

    Demirel, İsmail; Kavak, Burçin Salih; Özer, Ayşe B.; Bayar, Mustafa K.; Erhan, Ömer L.

    2014-01-01

    Objective The aim of this study was to retrospectively evaluate the intensive care unit treatments applied to obstetrics patients with a diagnosis of posterior reversible encephalopathy syndrome (PRES). Material and Methods The cases of 7 pregnant patients who had been diagnosed with PRES between July 2011 and July 2013 were retrospectively reviewed. The patients’ clinical data, brain magnetic resonance imaging (MRI) images before and after treatment, and neuropsychological tests were evaluated. Results Five out of 7 patients had eclampsia, 1 patient had severe preeclampsia, and 1 patient developed HELLP syndrome secondary to PRES. Calcium channel blockers and β-blockers were used as antihypertensive treatment. All patients were treated with parenteral magnesium sulfate. In addition, sodium thiopental was given to control sedation and convulsions in all patients except 1. The neurological and radiological findings of all cases treated in the intensive care unit improved. Conclusion Posterior reversible encephalopathy syndrome is a clinical condition with a multifactorial etiology and can result in different clinical findings. Radiological imaging techniques can be used for the diagnosis of PRES. Pregnancy and the postpartum period often lead to this syndrome. In some cases, PRES can cause irreversible neurological deficits or death. For patients with severe radiological findings, early diagnosis and thiopental infusion, in addition to treatment with antihypertensive agents and magnesium sulfate, may lead to quicker and more effective recovery from clinical manifestations. We suggest supplementation of standard treatment with early thiopental infusion. PMID:25584029

  9. Imaging Findings in Pediatric Posterior Reversible Encephalopathy Syndrome (PRES): 5 Years of Experience From a Tertiary Care Center in India.

    PubMed

    Gupta, Vivek; Bhatia, Vikas; Khandelwal, Niranjan; Singh, Paramjeet; Singhi, Pratibha

    2016-08-01

    This study sought to evaluate the radiological and clinical spectrum of posterior reversible encephalopathy syndrome (PRES) in pediatric population. A retrospective evaluation of the pediatric patients with posterior reversible encephalopathy syndrome seen over the last 5 years in the authors' hospital was done. The magnetic resonance imaging (MRI) findings were analyzed, and a review of literature was performed. Out of 32 pediatric patients of posterior reversible encephalopathy syndrome, 10 (31.25%) were males and 22 (68.75%) were females, with a mean age of 10.6 years. Renal disease (62.5%) was the most common primary disease, followed by chemotherapy for hemato-oncologic malignancies (15.6%). Hypertension was present in 81.2% of cases. Atypical MRI findings were seen in 62.5% cases. Frontal involvement was common and seen in 56% of the cases. Overall, MRI findings considered atypical in adults were found to be common in the series of pediatric posterior reversible encephalopathy syndrome. The understanding of the clinical settings and familiarity with radiological findings in pediatric posterior reversible encephalopathy syndrome patients is important to adequately treat these patients and to avoid misdiagnosis. PMID:27071468

  10. Posterior Reversible Encephalopathy Syndrome in Henoch-Schonlein Purpura and Hemolytic Uremic Syndrome.

    PubMed

    Fidan, Kibriya; Kandur, Yasar; Ucar, Murat; Gucuyener, Kivilcim; Soylemezoglu, Oguz

    2016-07-01

    Posterior reversible encephalopathy syndrome (PRES) is a clinico-radiological syndrome, composed of symptoms such as headache, seizures, visual disturbances, lethargy, confusion, stupor, focal neurologic findings and radiological findings of bilateral gray and white matter abnormalities suggestive of edema in the posterior regions of the cerebral hemispheres. PRES is associated with significant morbidity and mortality if it is not expeditiously recognized. Magnetic resonance image (MRI) represents the most sensitive imaging technique for recognizing PRES. PRES has been seen in various clinical settings including renal disorders such as acute glomerulonephritis, lupus nephritis, nephrotic syndrome, and drug usage such as calcineurin inhibitors. We aimed to present two study cases for such clinical setting. In this report, we present two patients with PRES in whom the primary diagnosis was hemolytic uremic syndrome (HUS) and Henoch-Schonlein purpura (HSP). Both of them were treated with anticonvulsant and proper antihypertensive drugs. A repeated MRI scan of the head, an ophthalmologic assessment, and a follow-up electroencephalogram produced normal results with no sequelae. Early recognition of PRES as a complication during different diseases and therapies in childhood may facilitate the appropriate treatment, so that intensive treatment should be performed as soon as possible to avoid neurological sequelae. PMID:27298664

  11. [Recurrent posterior reversible encephalopathy due to vasospasm and cerebral hypoperfusionin in acute leukemia: a case report].

    PubMed

    Hiraide, Takuya; Matsubayashi, Tomoko; Ishigaki, Hidetoshi; Asahina, Miki; Sakaguchi, Kimiyoshi; Fukuda, Tokiko

    2015-11-01

    We report the case of a 4-year-old girl who presented with recurrent posterior reversible encephalopathy syndrome (PRES). She was diagnosed with B-precursor acute lymphocytic leukemia (ALL), and was administered remission-induction chemotherapy. On day 28 of the induction therapy, she experienced seizure and prolonged unconsciousness. Blood pressure was slightly elevated. MRI revealed cortical cytotoxic edema in the right temporal and occipital lobes. In the right occipital white matter the lesion with vasogenic edema also existed. Three days later, MRI showed vasogenic edema in subcortical white matter of the right temporal right occipital and bilateral occipital lobes. The lesions had receded with time. Since the seizure occurred, the chemotherapy had been discontinued. The episodes of seizure and prolonged consciousness recurred 22 days later. MRI revealed vasogenic edema in the right occipital lobe, and MR angiography demonstrated vessel irregularity and reduced branch visualization in the middle and posterior cerebral arteries. Arterial spin-labeling (ASL) showed hypoperfusion in both occipital lobes. It suggests that vasoconstriction and hypoperfusion could lead to recurrent PRES in this case. It is possible that ASL might be more sensitive than MRI in detecting the lesions of PRES. It should be noted that PRES might recur in leukemia. PMID:26717647

  12. Subarachnoid hemorrhage due to ruptured intracranial aneurysm following posterior reversible encephalopathy syndrome.

    PubMed

    Nanba, Takamasa; Kashimura, Hiroshi; Saura, Hiroaki; Takeda, Masaru

    2016-01-01

    Although posterior reversible encephalopathy syndrome (PRES) is rarely associated with subarachnoid hemorrhage, to our knowledge, rupture of a concomitant cerebral aneurysm following PRES has not been reported. We describe a patient with atypical PRES involving the brainstem, thalamus, and periventricular white matter without cortical or subcortical edema of the parietooccipital lobe on magnetic resonance imaging, with rupture of a concomitant cerebral aneurysm. Preexisting extremely high blood pressure may trigger atypical PRES, and failure to lower blood pressure may lead to a concomitant aneurysm rupture. In the future treatment of hypertensive urgency with a recurrence of symptoms and mean arterial blood pressure >150 mmHg, it is advisable to immediately hospitalize the patient for aggressive blood pressure management, especially if PRES is suspected based on clinical and radiological features. PMID:27365964

  13. Iatrogenic Coagulopathy and the Development of Posterior Reversible Encephalopathy Syndrome after L-asparaginase Chemotherapy.

    PubMed

    Rota, Eugenia; Vallisa, Daniele; Morelli, Nicola; Scagnelli, Paola

    2016-01-01

    Posterior reversible encephalopathy syndrome (PRES) is a clinical and radiological syndrome mostly related to hypertension, eclampsia, renal failure, or to chemotherapy and/or immunosuppressive drugs. Although the PRES pathophysiology is multifactorial, hypertension and endothelial dysfunction are hypothesized to be the pivotal factors. Here we report a case of PRES in an adult patient after chemotherapy (Escherichia coli L-asparaginase [L-ASP], daunorubicin, vincristine, and intrathecal methotrexate) for acute lymphoblastic leukemia. The development of the PRES was strictly associated with an iatrogenic coagulopathy induced by L-ASP, which inhibits the biosynthesis of hepatic coagulation factors. The nadir of platelet count, antithrombin III (ATIII) and fibrinogen curve was coincident with the onset of the PRES neurological picture; subsequently, the normalization of the ATIII and fibrinogen levels seemed to parallel the good clinical evolution. This case seems to provide new insights into the PRES pathophysiological mechanisms. PMID:27014503

  14. Posterior Reversible Encephalopathy Syndrome with Bilateral Independent Epileptic Foci Precipitated By Guillain-Barrè Syndrome.

    PubMed

    Rossi, Rosario; Saddi, Maria Valeria; Mela, Alessandro; Ticca, Anna

    2016-01-01

    We report the case of a 56-year-old woman who developed status epilepticus (SE) related to independent occipital foci as clinical manifestation of posterior reversible encephalopathy syndrome (PRES) in the background of Guillain-Barrè syndrome (GBS). SE resulted from a series of focal seizures clinically characterized by left- and rightward deviations of the head and consequent oculoclonic movements. Electroencephalography recorded independent seizure activity in both occipital regions with alternate involvement of the two cerebral hemispheres. The epileptic foci corresponded topographically to parenchymal abnormalities of PRES in the occipital lobes. The manifestation of bilateral, independent occipital seizures with alternate deviations of the head and oculoclonic movements, previously not reported in patients with PRES, highlights the acute epileptogenicity of the cerebral lesions in this syndrome. Despite the variable clinical expression of seizures due to occipital damage in PRES, the development of independent seizure activity in both occipital lobes might represent a distinctive epileptic phenomenon of this encephalopathy. PMID:27403359

  15. Iatrogenic Coagulopathy and the Development of Posterior Reversible Encephalopathy Syndrome after L-asparaginase Chemotherapy

    PubMed Central

    Rota, Eugenia; Vallisa, Daniele; Morelli, Nicola; Scagnelli, Paola

    2016-01-01

    Posterior reversible encephalopathy syndrome (PRES) is a clinical and radiological syndrome mostly related to hypertension, eclampsia, renal failure, or to chemotherapy and/or immunosuppressive drugs. Although the PRES pathophysiology is multifactorial, hypertension and endothelial dysfunction are hypothesized to be the pivotal factors. Here we report a case of PRES in an adult patient after chemotherapy (Escherichia coli L-asparaginase [L-ASP], daunorubicin, vincristine, and intrathecal methotrexate) for acute lymphoblastic leukemia. The development of the PRES was strictly associated with an iatrogenic coagulopathy induced by L-ASP, which inhibits the biosynthesis of hepatic coagulation factors. The nadir of platelet count, antithrombin III (ATIII) and fibrinogen curve was coincident with the onset of the PRES neurological picture; subsequently, the normalization of the ATIII and fibrinogen levels seemed to parallel the good clinical evolution. This case seems to provide new insights into the PRES pathophysiological mechanisms. PMID:27014503

  16. Posterior Reversible Encephalopathy Syndrome in Pediatric Hematologic-Oncologic Disease: Literature Review and Case Presentation

    PubMed Central

    ARZANIAN, Mohammad Thaghi; SHAMSIAN, Bibi Shahin; KARIMZADEH, Parvaneh; KAJIYAZDI, Mohammad; MALEK, Fatima; HAMMOUD, Mohammad

    2014-01-01

    Objective Posterior reversible encephalopathy syndrome (PRES) is a cliniconeuroradiological disease entity, which is represented by characteristic magnetic resonance imaging (MRI) findings of subcortical/cortical hyperintensity in T2-weighted sequences. It is more often seen in parietaloccipital lobes, and is accompanied by clinical neurological changes. PRES is a rare central nervous system (CNS) complication in patients with childhood hematologic-oncologic disese and shows very different neurological symptoms between patients, ranging from numbness of extremities to generalized seizure. In this article, we will review PRES presentation in hematologic-oncologic patients. Then, we will present our patient, a 7-year-old boy with Evans syndrome on treatment with cyclosporine, mycophenolate mofetil (MMF) and prednisone, with seizure episodes and MRI finding in favour of PRES. PMID:24949044

  17. Posterior Reversible Encephalopathy Syndrome with Bilateral Independent Epileptic Foci Precipitated By Guillain-Barrè Syndrome

    PubMed Central

    Rossi, Rosario; Saddi, Maria Valeria; Mela, Alessandro; Ticca, Anna

    2016-01-01

    We report the case of a 56-year-old woman who developed status epilepticus (SE) related to independent occipital foci as clinical manifestation of posterior reversible encephalopathy syndrome (PRES) in the background of Guillain-Barrè syndrome (GBS). SE resulted from a series of focal seizures clinically characterized by left- and rightward deviations of the head and consequent oculoclonic movements. Electroencephalography recorded independent seizure activity in both occipital regions with alternate involvement of the two cerebral hemispheres. The epileptic foci corresponded topographically to parenchymal abnormalities of PRES in the occipital lobes. The manifestation of bilateral, independent occipital seizures with alternate deviations of the head and oculoclonic movements, previously not reported in patients with PRES, highlights the acute epileptogenicity of the cerebral lesions in this syndrome. Despite the variable clinical expression of seizures due to occipital damage in PRES, the development of independent seizure activity in both occipital lobes might represent a distinctive epileptic phenomenon of this encephalopathy. PMID:27403359

  18. Neuromyelitis Optica in Pregnancy Complicated by Posterior Reversible Encephalopathy Syndrome, Eclampsia and Fetal Death

    PubMed Central

    Igel, Catherine; Garretto, Diana; Robbins, Matthew S; Swerdlow, Michael; Judge, Nancy; Dayal, Ashlesha

    2015-01-01

    Neuromyelitis optica (NMO) is a demyelinating syndrome characterized by optic neuritis and acute myelitis with poor recovery and a progressive course. We report a poor outcome complicated by posterior reversible encephalopathy syndrome (PRES) and eclampsia and review available literature and current evidence for anticipation of adverse fetal and maternal effects. After a pregnancy complicated by multiple admissions for painful NMO exacerbations, a primiparous patient with seropositive NMO presented at 31 + 3/7 weeks with eclampsia, HELLP and subsequent fetal death. MRI confirmed PRES. NMO may be associated with eclampsia and leads to adverse maternal and fetal outcomes. Posited mechanisms include antibody-mediated placental damage and a heightened risk of eclampsia-associated PRES. Further characterization of the course of NMO and its relationship with pregnancy outcomes in larger series would be invaluable. PMID:25584107

  19. Subarachnoid hemorrhage due to ruptured intracranial aneurysm following posterior reversible encephalopathy syndrome

    PubMed Central

    Nanba, Takamasa; Kashimura, Hiroshi; Saura, Hiroaki; Takeda, Masaru

    2016-01-01

    Although posterior reversible encephalopathy syndrome (PRES) is rarely associated with subarachnoid hemorrhage, to our knowledge, rupture of a concomitant cerebral aneurysm following PRES has not been reported. We describe a patient with atypical PRES involving the brainstem, thalamus, and periventricular white matter without cortical or subcortical edema of the parietooccipital lobe on magnetic resonance imaging, with rupture of a concomitant cerebral aneurysm. Preexisting extremely high blood pressure may trigger atypical PRES, and failure to lower blood pressure may lead to a concomitant aneurysm rupture. In the future treatment of hypertensive urgency with a recurrence of symptoms and mean arterial blood pressure >150 mmHg, it is advisable to immediately hospitalize the patient for aggressive blood pressure management, especially if PRES is suspected based on clinical and radiological features. PMID:27365964

  20. Posterior reversible encephalopathy syndrome in malignant hypertension secondary to focal segmental glomerulosclerosis.

    PubMed

    Abdullah, Hafez Mohammad Ammar; Ullah, Waqas; Ahmad, Ejaz; Anwer, Faiz

    2016-01-01

    Posterior reversible encephalopathy syndrome (PRES) is a neurological condition that occurs secondary to a variety of causes like autoimmune diseases, uncontrolled hypertension and immunosuppressive agents. We report an unusual association of PRES and malignant hypertension secondary to focal segmental glomerulosclerosis in a young woman, presenting with sudden loss of vision and seizures. She had uncontrolled hypertension and a Glasgow Coma Scale of 6/15. Brain MRI revealed high signals in cortical and subcortical white matter and some involvement of the periventricular areas. She improved dramatically with antihypertensive and antiepileptic medications and was discharged home in a stable condition. It is important to have a high clinical suspicion for this uncommon condition in an appropriate clinical setting, because a timely intervention can prevent long-term complications. PMID:27535734

  1. Posterior Reversible Encephalopathy Syndrome Mimicking a Left Middle Cerebral Artery Stroke

    PubMed Central

    Terranova, Santo; Kumar, Jai Dev; Libman, Richard B

    2012-01-01

    Certain Acute Clinical presentations are highly suggestive of stroke caused by specific mechanisms. One example of this would be the sudden onset of aphasia without hemiparesis often reflecting cerebral embolism, frequently from a cardiac source. Posterior reversible encephalopathy syndrome (PRES) describes a usually reversible neurologic syndrome with a variety of presenting symptoms from headache, altered mental status, seizures, vomiting, diminished spontaneity and speech, abnormalities of visual perception and visual loss. We report a patient presenting with elevated blood pressure, CT characteristics of PRES but a highly circumscribed neurologic syndrome (Wernicke's Aphasia without hemiparesis) suggestive of a cardioembolic stroke affecting the left MCA territory. That is, PRES mimicked a focal stroke syndrome. The importance of recognizing this possibility is that his deficits resolved with blood pressure control, while other treatments, such as intensifying his anticoagulation would have been inappropriate. In addition, allowing his blood pressure to remain elevated as is often done in the setting of an acute stroke might have perpetuated the underlying pathophysiology of PRES leading to a worse clinical outcome. For this reason PRES needs to be recognized quickly and treated appropriately. PMID:22371821

  2. Posterior reversible encephalopathy syndrome (PRES) in a thirty-six-week gestation eclamptic.

    PubMed

    Powell, Emilie S; Goldman, Mitchell J

    2007-11-01

    Posterior reversible encephalopathy syndrome (PRES) is a transient clinical neuroradiological entity characterized by clinical signs and symptoms including hypertension, generalized seizure activity, altered mental status, headache, and vision changes; along with characteristic findings on head computed tomography or magnetic resonance imaging scan. Albeit a rare condition, PRES is most commonly reported in the literature in association with obstetric patients suffering from pre-eclampsia or eclampsia. In the acute setting, it is important to recognize the characteristics of PRES and immediately treat the inciting conditions: the patient's hypertension and seizures. Although this condition is usually transient and completely reversible, ischemic injury and irreversible damage have been reported. In the event of early and effective treatment, cognitive function may be completely restored. The following case report reviews a pregnant patient who presented to the Emergency Department with generalized seizure activity and a clinical picture characteristic of PRES. The case demonstrates how appropriate treatment in the acute setting allows complete restoration of cognitive function in the long term. PMID:17976748

  3. Reversible posterior leukoencephalopathy syndrome accompanying eclampsia: correct diagnosis using preoperative MRI.

    PubMed

    Ekawa, Yuka; Shiota, Mitsuru; Tobiume, Takako; Shimaoka, Masao; Tsuritani, Mitsuhiro; Kotani, Yasushi; Mizuno, Yoshiaki; Hoshiai, Hiroshi

    2012-01-01

    Reversible posterior leukoencephalopathy syndrome (RPLS) is characterized by clinical symptoms such as seizures, visual disturbance, and altered mental status. It also presents abnormal findings on computed tomography (CT) and magnetic resonance imaging (MRI) indicating cerebral edema in the white matter of the occipital, temporal, and parietal lobes. Both the clinical symptoms and abnormal imaging findings can be reversed by controlling blood pressure or treating the underlying condition including infection. This report describes a patient with RPLS that occurred secondary to eclampsia. A 26-year-old female, gravida 0 para 0, developed weakness and pain in her upper and lower extremities and gait disturbance during the 34th week of pregnancy, and severe pregnancy-induced hypertension near the end of the 37th week. On the first day of the 38th week, she developed constricted visual fields and complained of visual illusions. MRI revealed a high-signal-intensity area in the right occipital lobe. Immediately after MRI, the patient had a 10-sec tonic convulsion. Diagnosed with eclampsia, she underwent emergency cesarean section. MRI on the 2nd postoperative day showed that the high-signal-intensity area was slightly improved. Her visual illusions were diminished by the 4th postoperative day, and almost all subjective symptoms disappeared by the 7th postoperative day. The patient was discharged at 12th postoperative day. We recommend MRI not only for symptomatic patients with suspected RPLS, but also for asymptomatic patients with severe pregnancy-induced hypertension. If findings such as cerebral edema are observed on MRI, immediate delivery should be considered before eclamptic seizures or exacerbation of neurological symptoms. PMID:22186037

  4. Posterior reversible encephalopathy syndrome in a patient with a Chiari I malformation

    PubMed Central

    Hansberry, David R.; Agarwal, Nitin; Tomei, Krystal L.; Goldstein, Ira M.

    2013-01-01

    Background: The authors describe a unique case of a patient who developed posterior reversible encephalopathy syndrome (PRES) following postoperative treatment of a Chiari I malformation. Case Decsription: A 25-year-old female presented with complaints of left upper and lower extremity paresthesias and gait disturbances. A magnetic resonance imaging (MRI) of the brain and cervical spine showed a Chiari I malformation with tonsillar descent beyond the level of the C1 lamina. She underwent a suboccipital craniectomy and C1 laminectomy with cerebellar tonsillar cauterization and duraplasty. Postoperatively, an MRI showed bilateral acute infarcts of the cerebellar vermis. She was initially treated for cerebellar ischemia with hypertensive therapy with a subsequent decline in her neurologic status and generalized tonic–clonic seizure. Further workup showed evidence of PRES. After weaning pressors, the patient had a significant progressive improvement in her mental status. Conclusion: Although the mechanism of PRES remains controversial given its diverse clinical presentation, several theories implicate hypertension and steroid use as causative agents. PMID:24232171

  5. Posterior reversible encephalopathy syndrome (PRES) as a complication of Guillain-Barre' syndrome (GBS).

    PubMed

    Nabi, Sumaira; Rajput, Haris Majid; Badshah, Mazhar; Ahmed, Shahzad

    2016-01-01

    A 17-year-old Pakistani female patient presented with acute onset flaccid quadriparesis with nerve conduction studies showing demyelinating polyneuropathy consistent with Guillain-Barre' syndrome. She was treated with 4 plasmapheresis sessions. She developed raised blood pressure, headache, visual loss and generalised seizures on the 13th day of admission. MRI of the brain on contrast showed findings of altered signals low on T1-weighted image, high on T2-weighted image and fluid-attenuated inversion recovery in the white matter of bilateral occipital, parietal and right frontal lobe consistent with posterior reversible encephalopathy syndrome. The patient was administered antiepileptic and antihypertensive drugs to control seizures and blood pressure. She was discharged in a stable state. On follow-up her visual loss had recovered completely and she had regained full motor strength in all four extremities after 6 weeks. Fresh MRI of the brain revealed complete resolution of lesions. Antihypertensive and antiepileptic medication was discontinued. She is independent in all her daily activities. PMID:27489061

  6. Posterior reversible encephalopathy syndrome following acute pancreatitis during chemotherapy for acute monocytic leukemia.

    PubMed

    Nishimoto, Mitsutaka; Koh, Hideo; Bingo, Masato; Yoshida, Masahiro; Nanno, Satoru; Hayashi, Yoshiki; Nakane, Takahiko; Nakamae, Hirohisa; Shimono, Taro; Hino, Masayuki

    2014-05-01

    We describe an 18-year-old man with acute leukemia who presented with posterior reversible encephalopathy syndrome (PRES) shortly after developing acute pancreatitis. On day 15 after the third consolidation course with high-dose cytarabine, treatment with broad-spectrum antibiotics was initiated for febrile neutropenia. On day 16, he developed septic shock, and subsequently, acute respiratory distress syndrome (ARDS). After adding vancomycin, micafungin and high-dose methylprednisolone (mPSL) to his treatment regimen, these manifestations subsided. On day 22, he received hemodialysis for drug-induced acute renal failure. On day 24, he developed acute pancreatitis possibly due to mPSL; the following day he had generalized seizures, and was intubated. Cerebrospinal fluid findings were normal. Brain MRI revealed hyperintense signals on FLAIR images and increased apparent diffusion coefficient values in the sub-cortical and deep white matter areas of the bilateral temporal and occipital lobes, indicative of vasogenic edema. Thus, we diagnosed PRES. Blood pressure, seizures and volume status were controlled, with MRI findings showing improvement by day 42. He was extubated on day 32 and discharged on day 49 without complications. Although little is known about PRES following acute pancreatitis, clinicians should be aware that this condition may develop. PMID:24881921

  7. Posterior Reversible Encephalopathy Syndrome Complicating Traumatic Pancreatitis: A Pediatric Case Report.

    PubMed

    Sigurtà, Anna; Terzi, Valeria; Regna-Gladin, Caroline; Fumagalli, Roberto

    2016-05-01

    We are reporting a case of posterior reversible encephalopathy syndrome (PRES) developed in an unusual clinical scenario without the presence of the most described symptoms. PRES is a neurological and radiological syndrome described in many different clinical conditions. In children it has been mostly reported in association with hematological and renal disorders.Our patient was a 15 years old boy, admitted to our intensive care unit for pancreatitis after blunt abdominal trauma.During the stay in the intensive care unit, he underwent multiple abdominal surgical interventions for pancreatitis complications. He had a difficult management of analgesia and sedation, being often agitated with high arterial pressure, and he developed a bacterial peritonitis. After 29 days his neurological conditions abruptly worsened with neuroimaging findings consistent with PRES. His clinical conditions progressively improved after sedation and arterial pressure control.He was discharged at home with complete resolution of the neurological and imaging signs 2 months later.The pathophysiology of PRES is controversial and involves disordered autoregulation ascribable to hypertension and endothelial dysfunction. In this case both hypertension and endothelial activation, triggered by sepsis and pancreatitis, could represent the culprits of PRES onset. Even if there is no specific treatment for this condition, a diagnosis is mandatory to start antihypertensive and supportive treatment. We are therefore suggesting to consider PRES in the differential diagnosis of a neurological deterioration preceded by hypertension and/or septic state, even without other "typical" clinical features. PMID:27258506

  8. Reversible posterior leukoencephalopathy syndrome during sunitinib therapy for metastatic renal cell carcinoma.

    PubMed

    Hadj, Jamal Oulad; Braven, Rogier DEN; Tillier, Corrine; Schrijver, Hans M; Verheul, Henk M W; VAN DER Vliet, Hans J

    2012-06-01

    Sunitinib is an oral receptor tyrosine kinase inhibitor with potent antiangiogenic and antitumor activity that is approved for the treatment of advanced renal cell carcinoma (RCC), malignant gastrointestinal stromal tumors and pancreatic neuroendocrine tumors. Well-known side effects of sunitinib include hypertension, fatigue, thyroid dysfunction, cardiotoxicity, gastrointestinal toxicity and skin toxicity. In this study, we report the case of a 61-year-old male with papillary metastatic RCC who responded to sunitinib but developed generalized tonic-clonic seizures during the third cycle. Magnetic resonance imaging (MRI) was compatible with reversible posterior leukoencephalopathy syndrome (RPLS). After the administration of anti-epileptic drugs and the withdrawal of sunitinib there was rapid clinical improvement. Notably, radiological characteristics of RPLS persisted during second-line therapy with the mammalian target of rapamycin (mTOR) inhibitor everolimus and only resolved when everolimus was terminated due to disease progression. Although sunitinib-induced RPLS has been reported previously, our case is the first to additionally suggest that everolimus may sustain and therefore potentially contribute to the occurrence of RPLS. PMID:22783436

  9. Acute intermittent porphyria leading to posterior reversible encephalopathy syndrome (PRES): a rare cause of abdominal pain and seizures.

    PubMed

    Dagens, Andrew; Gilhooley, Michael James

    2016-01-01

    Acute intermittent porphyria (AIP) is an inherited deficiency in the haem biosynthesis pathway. AIP is rare, affecting around 1 in 75 000 people. Acute attacks are characterised by abdominal pain associated with autonomic, neurological and psychiatric symptoms. AIP is rarely associated with posterior reversible encephalopathy syndrome (PRES). PRES is a clinicoradiological condition caused by the failure of the posterior circulation to autoregulate, resulting in cerebral oedema, headaches, nausea and seizures. This association is important because drugs used in the management of seizures may worsen an attack of AIP. This article describes a case of AIP and PRES in a young woman. PMID:27277587

  10. Treatment of Posterior Reversible Encephalopathy Syndrome that Occurred in a Patient with Systemic Lupus Erythematosus by Plasmapheresis.

    PubMed

    Arslan, Zehra İpek; Turna, Canan Kamile; Özerdem, Çiğdem Yasemin; Yavuz, Sara; Baykara, Nur; Solak, Mine

    2015-08-01

    Posterior reversible encephalopathy syndrome is characterized by visual and mental disturbances, nausea and vomiting and generalized or focal convulsions and often represents itself with parietal and occipital oedema formation. We want to report the treatment of posterior reversible encephalopathy syndrome with plasmapheresis, which developed in a 35-year-old woman with systemic lupus erythematosus diagnosed by renal biopsy 3 years ago. She has been followed up in the intensive care unit three times. However, she had been transferred to the nephrology department of our university hospital because of her uncontrolled blood pressure. Oral antihypertensive therapy, corticosteroid 500 mg 1 × 1 and cyclophosphamide were started for the activation of lupus. After the detection of low complement levels, systemic lupus erythematosus activation was suspected. She developed mental deterioration after her first plasmapheresis treatment and was then consulted by the neurology and intensive care unit doctors. Diffusion cranial magnetic resonance imaging was found compatible with posterior reversible encephalopathy syndrome. The patient was transferred to our intensive care unit. The patient gained consciousness after her second plasmapheresis. After 5 days of follow-up in our intensive care unit and after significant regression was observed in the magnetic resonance imaging analysis, the patient was transferred to the nephrology service conscious, cooperated and orientated. At the nephrology service, after a total of 13 times of plasmapheresis, complement levels were increased and she was discharged with corticosteroid therapy. Posterior reversible encephalopathy syndrome can be observed in patients with systemic lupus erythematosus and intensive care unit treatment may be required. To control the hypertension, plasmapheresis should be kept in mind in addition to the multiple antihypertensive therapy in these patients. PMID:27366515

  11. Treatment of Posterior Reversible Encephalopathy Syndrome that Occurred in a Patient with Systemic Lupus Erythematosus by Plasmapheresis

    PubMed Central

    Arslan, Zehra İpek; Turna, Canan Kamile; Özerdem, Çiğdem Yasemin; Yavuz, Sara; Baykara, Nur; Solak, Mine

    2015-01-01

    Posterior reversible encephalopathy syndrome is characterized by visual and mental disturbances, nausea and vomiting and generalized or focal convulsions and often represents itself with parietal and occipital oedema formation. We want to report the treatment of posterior reversible encephalopathy syndrome with plasmapheresis, which developed in a 35-year-old woman with systemic lupus erythematosus diagnosed by renal biopsy 3 years ago. She has been followed up in the intensive care unit three times. However, she had been transferred to the nephrology department of our university hospital because of her uncontrolled blood pressure. Oral antihypertensive therapy, corticosteroid 500 mg 1 × 1 and cyclophosphamide were started for the activation of lupus. After the detection of low complement levels, systemic lupus erythematosus activation was suspected. She developed mental deterioration after her first plasmapheresis treatment and was then consulted by the neurology and intensive care unit doctors. Diffusion cranial magnetic resonance imaging was found compatible with posterior reversible encephalopathy syndrome. The patient was transferred to our intensive care unit. The patient gained consciousness after her second plasmapheresis. After 5 days of follow-up in our intensive care unit and after significant regression was observed in the magnetic resonance imaging analysis, the patient was transferred to the nephrology service conscious, cooperated and orientated. At the nephrology service, after a total of 13 times of plasmapheresis, complement levels were increased and she was discharged with corticosteroid therapy. Posterior reversible encephalopathy syndrome can be observed in patients with systemic lupus erythematosus and intensive care unit treatment may be required. To control the hypertension, plasmapheresis should be kept in mind in addition to the multiple antihypertensive therapy in these patients. PMID:27366515

  12. Posterior reversible encephalopathy syndrome in cancer patients: a single institution retrospective study.

    PubMed

    Kamiya-Matsuoka, Carlos; Paker, Asif M; Chi, Linda; Youssef, Ayda; Tummala, Sudhakar; Loghin, Monica E

    2016-05-01

    Posterior reversible encephalopathy syndrome (PRES) is a clinico-radiologic entity. Its management and outcome in the oncology population is limited because it is still difficult to identify despite an increasingly recognized occurrence. This is the largest retrospective study of PRES in cancer patients reported from a single institution. We explore the clinical manifestations and radiologic features to comprehensively assess PRES in order to prevent permanent neurologic deficits and mortality. We retrospectively identified 69 patients with cancer who developed PRES at MDACC between 01/2006 to 06/2012. Clinical and radiographic data were abstracted from their records and reviewed for our analysis. Mean age at PRES onset was 52 ± 17.8 years. Fifty-two (75 %; p < 0.001) patients were women. Most common diagnoses were leukemia (30 %) and lymphoma (12 %). Forty-eight (70 %) patients were treated with chemotherapy, 21 (30 %) bone marrow transplant and 14 (20 %) tacrolimus. Most common clinical presentation was seizures (67 %). PRES was associated with hypertension in 62 (90 %) patients. On brain MRI, 33 (44 %) patients had some evidence of hemorrhage, 22 (73 %) of these were thrombocytopenic. Thirty-five (51 %) patients fully recovered and 19 (28 %) had permanent neurological deficits. Morbidity and mortality were associated with continuation with offending agent, thrombocytopenia, variations in mean arterial pressure ≥20 mmHg, electrographic seizures at onset, atypical MRI pattern and delay in diagnostic imaging (7.4 ± 4.8 days vs. 1.9 ± 1.8 days; p = 0.031) as half of them did not receive a prompt intervention. Special attention should be given to patients who present with high-risk factors in order to prevent development of PRES or decrease patient morbidity and mortality. Management of PRES should be guided by the radiographic findings. Overall, early recognition, discontinuation of the offending agents, correction of thrombocytopenia

  13. Posterior Reversible Encephalopathy Syndrome Resolving Within 48 Hours in a Normotensive Patient Who Underwent Thoracic Spine Surgery

    PubMed Central

    Vakharia, Kunal; Siasios, Ioannis; Dimopoulos, Vassilios G.; Pollina, John

    2016-01-01

    Posterior reversible encephalopathy syndrome (PRES) usually manifests with severe headaches, seizures, and visual disturbances due to uncontrollable hypertension. A patient (age in the early 60s) with a history of renal cell cancer presented with lower-extremity weakness and paresthesias. Magnetic resonance imaging (MRI) of the thoracic spine revealed a T8 vertebral body metastatic lesion with cord compression at that level. The patient underwent preoperative embolization of the tumor followed by posterior resection and placement of percutaneous pedicle screws and rods. Postoperatively, the patient experienced decreased visual acuity bilaterally. Abnormal MRI findings consisted of T2 hyperintense lesions and fluid-attenuated inversion recovery changes in both occipital lobes, consistent with the unique brain imaging pattern associated with PRES. The patient’s blood pressure was normal and stable from the first day of hospitalization. The patient was kept on high-dose steroid therapy, which was started intraoperatively, and improved within 48 hours after symptom onset. PMID:26858804

  14. Deep brain stimulation of the posterior hypothalamic nucleus reverses akinesia in bilaterally 6-hydroxydopamine-lesioned rats.

    PubMed

    Young, C K; Koke, S J; Kiss, Z H; Bland, B H

    2009-08-01

    Deep brain stimulation (DBS) of the basal ganglia motor circuitry is a highly effective treatment for the debilitating motor symptoms of Parkinson's disease (PD). However, recent findings have indicated promising potential for PD therapy with DBS in brain structures outside the basal ganglia. For example, high frequency stimulation of the posterior hypothalamic nucleus (PH) can reverse haloperidol-induced akinesia in rats [Jackson J, Young CK, Hu B, Bland BH (2008) High frequency stimulation of the posterior hypothalamic nucleus restores movement and reinstates hippocampal-striatal theta coherence following haloperidol-induced catalepsy. Exp Neurol 213:210-219]. In the current study, we used the bilateral 6-hydroxydopamine lesion model of Parkinsonian akinesia in male Long-Evans rats to further explore the efficacy of PH DBS. The application of PH DBS in lesioned animals reversed akinesia in an active avoidance paradigm with increased latency compared to pre-lesion performance. The dramatic reversal of akinesia in two models of rodent Parkinsonism by PH DBS warrants further exploration of its therapeutic potential. PMID:19401216

  15. Comparison of the Posterior Capsule Rupture Rates Associated with Conventional (Start to Finish) Versus Reverse Methods of Teaching Phacoemulsification

    PubMed Central

    Suryawanshi, Milind; Gogate, Parikshit; Kulkarni, Anil N.; Biradar, Archana; Bhomaj, Pooja

    2016-01-01

    Purpose: Comparison of the rates of posterior capsule rupture (PCR) associated with conventional versus a reverse method of teaching phacoemulsification. Methods: Trainees were taught conventional (start-to-finish) phacoemulsification beginning with an incision (tunnel construction) to capsulorhexis, sculpting, nucleus cracking, segment removal, cortex aspiration, intraocular lens implantation, and viscoelastic removal. In the reverse method, after incision and capsulorhexis, the trainees were progressively taught viscoelastic wash, cortex aspiration, segment removal, nucleus cracking, sculpting, and intraocular lens implantation. Trainees from a Tertiary Eye Care Centre were classified as beginners, for their first 30 cases and then trainees for their next 70 surgeries. Data were collected on posterior capsular rent and vitreous loss during each step of training. Results: Thirty-two ophthalmic surgeons learning phacoemulsification surgery on 609 cataracts cases were supervised by 3 trainers. Fifteen beginners performed 287 surgeries using the conventional method, and 17 beginners performed 322 surgeries with the reverse method. The incidence of PCR was 18/287 (6.2%) with the conventional method and 15/322 (4.6%) with the reverse method (P = 0.38). PCR occurred during cortex aspiration (8/287, 2.8%) and segment removal (5/287, 1.7%) in the conventional method. PCR occurred during nucleus cracking, segment removal, and cortex aspiration (4/322 surgeries for each step, 1.2%). In the follow, 70 cases (trainees) there was no difference in PCR with either method (4.7% vs. 4.3%, P = 0.705). Conclusion: Conventional and reverse method for training phacoemulsification were both safe in a supervised setting. PMID:27162446

  16. Posterior reversible encephalopathy syndrome in a child with steroid-resistant nephrotic syndrome: a case report and review of literature.

    PubMed

    Zhang, Yu; Zhou, Jianhua; Chen, Yu

    2014-01-01

    Posterior reversible encephalopathy syndrome (PRES) is a rare and serious syndrome of central nervous system that can develop in both adults and children. It is characterized by acute onset of headache, confusion, seizures or focal neurological deficits along with radiological findings of white matter abnormalities in the parietal and occipital lobes. In the past ten years, this syndrome has been described mainly in adults, rare in children. Here, we report a case of PRES presenting in a 12-year-old girl with steroid-resistant nephrotic syndrome. Her neurological symptom was rapidly recovered after control of hypertension without discontinuation of cyclosporine A. PMID:25120830

  17. Posterior reversible encephalopathy syndrome in a child with steroid-resistant nephrotic syndrome: a case report and review of literature

    PubMed Central

    Zhang, Yu; Zhou, Jianhua; Chen, Yu

    2014-01-01

    Posterior reversible encephalopathy syndrome (PRES) is a rare and serious syndrome of central nervous system that can develop in both adults and children. It is characterized by acute onset of headache, confusion, seizures or focal neurological deficits along with radiological findings of white matter abnormalities in the parietal and occipital lobes. In the past ten years, this syndrome has been described mainly in adults, rare in children. Here, we report a case of PRES presenting in a 12-year-old girl with steroid-resistant nephrotic syndrome. Her neurological symptom was rapidly recovered after control of hypertension without discontinuation of cyclosporine A. PMID:25120830

  18. [Posterior reversible encephalopathy syndrome and cerebrovascular constriction syndrome in the differential diagnosis of post-partum headaches].

    PubMed

    Ruiz López, N; Cano Hernández, B; Balbás Álvarez, S

    2016-02-01

    Postpartum headache can be due to many causes. In a patient with previous epidural analgesia, the headache can be attributed to post-dural puncture headache, even if the symptoms are not typical of this clinical entity. We report a case of a post-partum with accidental dural tap during the insertion of an epidural catheter for labour analgesia, and who referred to headaches in the third post-partum day. Initially, a post-dural puncture headache was suspected, but the subsequent onset of seizures and visual impairment meant that the diagnosis had to be reconsidered. In this case report, the clinical and pathophysiological features of posterior reversible encephalopathy syndrome and reversible cerebral vasoconstriction syndrome, as well as the differential diagnosis of post-partum headaches are described. PMID:26056067

  19. Posterior Reversible Encephalopathy Syndrome after Surgical Resection of a Giant Vestibular Schwannoma: Case Report and Literature Review.

    PubMed

    Sorour, Mohammad; Sayama, Christina; Couldwell, William T

    2016-05-01

    Background Posterior reversible encephalopathy syndrome (PRES) is a constellation of neurologic symptoms-seizures, headaches, altered mental status, and visual changes-associated with characteristic brain magnetic resonance imaging findings seen on T2 and fluid-attenuated inversion recovery sequences. Classically, this condition is caused by hypertension, but several other risk factors have been described. The development of PRES after surgical resection of posterior fossa tumors has mostly been linked to the pediatric neurosurgical practice. Case Report We report the first case of PRES after resection of a giant vestibular schwannoma in an adult patient. This 57-year-old female patient underwent a retrosigmoid approach for total resection of her left-sided giant tumor. On the second postoperative day, she developed the classic clinical and radiologic characteristics of PRES. She was treated aggressively with antihypertensive and anticonvulsant medications and showed complete recovery without sequelae. Conclusion PRES is a potential yet rare complication of surgeries to posterior fossa tumors that are compressing the brainstem. Rapid diagnosis and aggressive management are essential for achieving the best outcome. PMID:26091111

  20. Mental reversal of imagined melodies: a role for the posterior parietal cortex.

    PubMed

    Zatorre, Robert J; Halpern, Andrea R; Bouffard, Marc

    2010-04-01

    Two fMRI experiments explored the neural substrates of a musical imagery task that required manipulation of the imagined sounds: temporal reversal of a melody. Musicians were presented with the first few notes of a familiar tune (Experiment 1) or its title (Experiment 2), followed by a string of notes that was either an exact or an inexact reversal. The task was to judge whether the second string was correct or not by mentally reversing all its notes, thus requiring both maintenance and manipulation of the represented string. Both experiments showed considerable activation of the superior parietal lobe (intraparietal sulcus) during the reversal process. Ventrolateral and dorsolateral frontal cortices were also activated, consistent with the memory load required during the task. We also found weaker evidence for some activation of right auditory cortex in both studies, congruent with results from previous simpler music imagery tasks. We interpret these results in the context of other mental transformation tasks, such as mental rotation in the visual domain, which are known to recruit the intraparietal sulcus region, and we propose that this region subserves general computations that require transformations of a sensory input. Mental imagery tasks may thus have both task or modality-specific components as well as components that supersede any specific codes and instead represent amodal mental manipulation. PMID:19366283

  1. [Posterior reversible encephalopathy syndrome of the midbrain and hypothalamus - a case report of uremic encephalopathy presenting with hypersomnia].

    PubMed

    Shiga, Yuji; Kanaya, Yuhei; Kono, Ryuhei; Takeshima, Shinichi; Shimoe, Yutaka; Kuriyama, Masaru

    2016-01-01

    We report the case of a 73-year-old woman presenting with hypersomnia and loss of appetite. She suffered from diabetic nephropathy without receiving dialysis, in addition to hypertension, which was well controlled without marked fluctuation. There were no objective neurological findings. Her laboratory findings showed renal failure with 3.7 mg/dl of serum creatinine and decreased serum sodium and potassium. Brain magnetic resonance imaging (MRI) showed posterior reversible encephalopathy syndrome (PRES) with vasogenic edema, which was distributed in the dorsal midbrain, medial thalamus, and hypothalamus. After we addressed the electrolyte imbalance and dehydration, her symptoms and MRI findings gradually improved, but faint high signals on MRI were still present 3 months later. Orexin in the cerebrospinal fluid was decreased on admission, but improved 6 months later. We diagnosed uremic encephalopathy with atypical form PRES showing functional disturbance of the hypothalamus. PMID:26640128

  2. Calcineurin Inhibitors Associated Posterior Reversible Encephalopathy Syndrome in Solid Organ Transplantation: Report of 2 Cases and Literature Review.

    PubMed

    Song, Turun; Rao, Zhengsheng; Tan, Qiling; Qiu, Yang; Liu, Jinpeng; Huang, Zhongli; Wang, Xianding; Lin, Tao

    2016-04-01

    Posterior reversible encephalopathy syndrome (PRES) is a rare neurologic side effect of calcineurin inhibitors (CNIs) with poorly understood clinical features.We report cases of 2 patients with PRES developing after kidney transplantation and summarize PRES clinical features through a literature review.The 1st case was a 28-year-old man who received a kidney transplant from a deceased donor. Initial immunosuppressive therapy consisted of tacrolimus/mycophenolate mofetil/prednisolone. He developed headache and blurred vision with visual field loss15 days after transplantation and generalized seizures 4 days later. The 2nd case was a 34-year-old man who received a living kidney transplant. His initial immunosuppressive therapy comprised tacrolimus/mycophenolate mofetil/prednisolone. Two months after transplantation, he developed seizures. Both patients were diagnosed with PRES based on neurological symptoms and magnetic resonance imaging (MRI) findings; they recovered after switching from tacrolimus to either a cyclosporine or a lower tacrolimus dose. CNI-associated PRES is an acute neurological syndrome with seizures, encephalopathy, visual abnormalities, headache, focal neurological deficits, and nausea/vomiting. It is always accompanied by hypertension. A fluid-attenuated inversion recovery signal MRI scan typically shows reversible subcortical white matter changes in the posterior cerebral hemisphere that usually occur within the 1st month after transplantation. CNI-associated PRES has a generally favorable prognosis with early diagnosis and prompt treatment including alternating or discontinuing CNIs and blood pressure control.CNI-associated PRES should be considered in patients exhibiting acute neurological symptoms after transplantation. Early diagnosis and immediate treatment are critical for a favorable prognosis. PMID:27057842

  3. [Unilateral Posterior Reversible Encephalopathy Syndrome after Ventriculo-Peritoneal Shunt for Normal Pressure Hydrocephalus Following Subarachnoid Hemorrhage: A Case Report].

    PubMed

    Sato, Hiroyuki; Koizumi, Takayuki; Sato, Daisuke; Endo, Shin; Kato, Syunichi

    2016-06-01

    The patient, a 79-year-old man, experienced a Hunt & Kosnik grade IV subarachnoid hemorrhage, presenting with sudden-onset coma and severe left hemiplegia. We performed cranial clipping surgery for a ruptured aneurysm on the right middle cerebral artery the same day. Post-operative recovery proceeded smoothly, with gradual improvements in disturbed consciousness and left hemiplegia. Three weeks post-operation, CT revealed low-density areas in the right frontal and temporal lobe, believed to be due to subarachnoid hemorrhage, as well as hydrocephaly. We then performed a lumbo-peritoneal (L-P) shunt for the hydrocephaly. Two months later, the patient experienced shunt occlusion, and we performed a ventriculo-peritoneal (V-P) shunt revision (pressure: 6 cm H(2)O). Headaches, severe decline in cognitive function, and worsened left hemiplegia were observed seven weeks post-shunt revision. Cranial CT revealed widespread low-density areas in right posterior cerebral white matter. We suspected unilateral posterior reversible encephalopathy syndrome (PRES) after performing cranial MRI and cerebral angiography. Increasing the set pressure of the shunt improved the symptoms and radiographic findings. PRES is typically bilateral, and unilateral incidents are rare. This is the first report of unilateral PRES secondary to shunt operation. Its unilaterality appears to have been caused by unilateral brain damage or adhesions to the brain surface from the subarachnoid cerebral hemorrhage. Overdrainage post-shunt can also induce PRES. Diagnosis of PRES is more difficult in unilateral cases;practitioners must keep PRES in mind as a rare complication post-shunt operation. PMID:27270150

  4. A Case of Posterior Reversible Encephalopathy Syndrome Associated with Gilenya® (Fingolimod) Treatment for Multiple Sclerosis

    PubMed Central

    Lindå, Hans; von Heijne, Anders

    2015-01-01

    We describe posterior reversible encephalopathy syndrome (PRES) in a woman with multiple sclerosis treated with Gilenya® (Fingolimod). The first symptoms appeared after 21 months of fingolimod treatment. She experienced headache, altered mental status, cognitive deficits, seizures, and visual disturbances. Not at any time during the course of the disease could any signs of infection or rheumatic disorder be detected. Test for anti-neuronal antibodies was also negative. Her blood pressure was normal. MRI showed widespread cortical and subcortical changes with some mass-effect in the temporo-occipital-parietal lobes in the left hemisphere. Contrast enhancement was seen in the leptomeninges and, in addition, there were no areas with restricted diffusion and no signs of hemorrhage. Her condition deteriorated until fingolimod was discontinued. Slowly her condition improved and after 8 months, the only symptoms that remained were two small, non-corresponding, right inferior scotomas. We believe that all symptoms, the clinical course, and the MRI findings in this case can all be explained by considering PRES, a probably rare, but serious, side effect of fingolimod treatment. PMID:25788891

  5. [Posterior reversible encephalopathy syndrome due to hypocalcemia: a description of a case and an analysis of a pathogenic role of electrolyte disturbances].

    PubMed

    Dobrynina, L A; Kalashnikova, L A; Bakulin, I S; Kremneva, E I; Krotenkova, M V; Shamtieva, K V

    2016-01-01

    Afemale patient with recurrent posterior reversible encephalopathy syndrome, severe hypocalcemia due to extirpation of the parathyroid glands is described. The disease was characterized by the acute development of headache, seizures, cognitive and behavioral disorders, mental confusion, transitory blood pressure increasing. The vasogenic edema in the posterior parts of the brain, detected by CT at the first exacerbation,was completely regressed. The residual neurological deficit and MRI changes remained after the recurrent exacerbations. Main clinical features of PRESare explained by hypocalcemia and accompanying electrolyte disturbances.The reported case shows the necessity to study blood electrolytes in patients with PRES to clarify their pathogenic role and the necessity of drug correction. PMID:27500881

  6. Reversible Deactivation of Motor Cortex Reveals Functional Connectivity with Posterior Parietal Cortex in the Prosimian Galago (Otolemur garnettii)

    PubMed Central

    Cooke, Dylan F.; Stepniewska, Iwona; Miller, Daniel J.; Kaas, Jon H.

    2015-01-01

    We examined the functional macrocircuitry of frontoparietal networks in the neocortex of prosimian primates (Otolemur garnettii) using a microfluidic thermal regulator to reversibly deactivate selected regions of motor cortex (M1). During deactivation of either forelimb or mouth/face movement domains within M1, we used long-train intracortical microstimulation techniques to evoke movements from the rostral division of posterior parietal cortex (PPCr). We found that deactivation of M1 movement domains in most instances abolished movements evoked in PPCr. The most common effect of deactivating M1 was to abolish evoked movements in a homotopic domain in PPCr. For example, deactivating M1 forelimb lift domains resulted in loss of evoked movement in forelimb domains in PPCr. However, at some sites, we also observed heterotopic effects; deactivating a specific domain in M1 (e.g., forelimb lift) resulted in loss of evoked movement in a different movement domain in PPCr (e.g., hand-to-mouth or eye-blink). At most sites examined in PPCr, rewarming M1 resulted in a reestablishment of the baseline movement at the same amplitude as that observed before cooling. However, at some sites, reactivation did not result in a return to baseline movement or to the full amplitude of the baseline movement. We discuss our findings in the context of frontoparietal circuits and how they may subserve a repertoire of ecologically relevant behaviors. SIGNIFICANCE STATEMENT The posterior parietal cortex (PPC) of primates integrates sensory information used to guide movements. Different modules within PPC and motor cortex (M1) appear to control various motor behaviors (e.g., reaching, defense, and feeding). How these modules work together may vary across species and may explain differences in dexterity and even the capacity for tool use. We investigated the functional connectivity of these modules in galagos, a prosimian primate with relatively simple frontoparietal circuitry. By deactivating a

  7. A semi-dominant mutation in the general splicing factor SF3a66 causes anterior-posterior axis reversal in one-cell stage C. elegans embryos.

    PubMed

    Keikhaee, Mohammad R; Nash, Eric B; O'Rourke, Sean M; Bowerman, Bruce

    2014-01-01

    Establishment of anterior-posterior polarity in one-cell stage Caenorhabditis elegans embryos depends in part on astral microtubules. As the zygote enters mitosis, these microtubules promote the establishment of a posterior pole by binding to and protecting a cytoplasmic pool of the posterior polarity protein PAR-2 from phosphorylation by the cortically localized anterior polarity protein PKC-3. Prior to activation of the sperm aster, the oocyte Meiosis I and II spindles assemble and function, usually at the future anterior pole, but these meiotic spindle microtubules fail to establish posterior polarity through PAR-2. Here we show that a semi-dominant mutation in the general splicing factor SF3a66 can lead to a reversed axis of AP polarity that depends on PAR-2 and possibly on close proximity of oocyte meiotic spindles with the cell cortex. One possible explanation is that reduced levels of PKC-3, due to a general splicing defect, can result in axis reversal due to a failure to prevent oocyte meiotic spindle microtubules from interfering with AP axis formation. PMID:25188372

  8. Differential Impact of Posterior Lesions in the Left and Right Hemisphere on Visual Category Learning and Generalization to Contrast Reversal

    ERIC Educational Resources Information Center

    Langguth, Berthold; Juttner, Martin; Landis, Theodor; Regard, Marianne; Rentschler, Ingo

    2009-01-01

    Hemispheric differences in the learning and generalization of pattern categories were explored in two experiments involving sixteen patients with unilateral posterior, cerebral lesions in the left (LH) or right (RH) hemisphere. In each experiment participants were first trained to criterion in a supervised learning paradigm to categorize a set of…

  9. Neurological PRESentations in Sickle Cell Patients Are Not Always Stroke: A Review of Posterior Reversible Encephalopathy Syndrome in Sickle Cell Disease.

    PubMed

    Solh, Ziad; Taccone, Michael S; Marin, Samantha; Athale, Uma; Breakey, Vicky R

    2016-06-01

    Acute neurological changes in sickle cell disease (SCD) patients often raise the suspicion for stroke. Posterior reversible encephalopathy syndrome (PRES) can mimic stroke in its clinical presentation. We aimed to (i) review the PRES literature in SCD patients including clinical presentation, risk factors, pathophysiology, and management and (ii) elucidate the distinction between PRES and stroke in SCD. The exact pathophysiology of PRES in SCD remains elusive but is likely multifactorial and related to sickling, ischemia, and chronic anemia predisposing to vasogenic edema. PRES and stroke in SCD are distinguishable conditions. Our review may help elucidate a clinical approach to this distinction. PMID:26871763

  10. Release of severe post-burn contracture of the first web space using the reverse posterior interosseous flap: Our experience with 12 cases.

    PubMed

    Kai, Shi; Zhao, Jingchun; Jin, Zhenghua; Wu, Weiwei; Yang, Ming; Wang, Yan; Xie, Chunhui; Yu, Jiaao

    2013-09-01

    We retrospectively assessed outcomes after treating severe contractures of the first web space from burns with the reverse posterior interosseous flaps (RPIF). Twelve consecutive patients (ages 18-58 years) with burns from 10% to 70% (mean, 30.1%) total body surface area and severe contractures of the first web space of the hand (initial thumb to index angles from 10° to 35° [mean, 23°]) underwent contracture release using the RPIF. Seventeen RPIFs were used, with sizes from 9cm×6cm to 14cm×10cm (mean area, 83.6cm(2)). The patients were followed for 5-26 months. All flaps survived completely, rapidly adapted to the recipient beds, and achieved good color and texture harmony. No early complications occurred. Fifteen donor sites were closed with skin grafts. Two donor sites were closed by direct suture. No paralysis of the posterior interosseous nerve was observed in these cases. At last follow-up the mean thumb to index angle was 78°, increasing the web length 260%. All patients regained fundamental hand functions. The RPIF is reliable and safe for releasing severe contractures of the first web space of the hand after burn, with distinct advantages over currently used alternative methods. PMID:23523223

  11. Occipital artery-to-posterior inferior cerebellar artery anastomosis with multiple-layer dissection of suboccipital muscles under a reverse C-shaped skin incision.

    PubMed

    Katsuno, Makoto; Tanikawa, Rokuya; Uemori, Genki; Kawasaki, Kazutsune; Izumi, Naoto; Hashimoto, Masaaki

    2015-06-01

    Although occipital artery (OA)-to-posterior inferior cerebellar artery (PICA) anastomosis is the most familiar reconstruction for posterior cerebral circulation, the procedure is considered difficult because of the anatomical complex course of OA and the depth of the operative field at the anastomosis site. Therefore, we attempted a safe and reliable method for OA-to-PICA anastomosis under multiple-layer dissection of suboccipital muscles and a reverse C-shaped skin incision. We reviewed the clinical records of patients who underwent OA-to-PICA anastomosis in our institute, and report the outcome with special emphasis on graft patency and surgical complications. Nine patients are described. In one patient the bypass was accomplished at the cortical segment of the PICA and in all others at the caudal loop. The average time for de-clamping the PICA was 29 min and 29 s. Although the overall graft patency rate was 100%, one patient showed a new medulla infarction at the time of post-operatory three-dimensional computed tomography angiography. Besides a secure OA-to-PICA anastomosis, this technique allows safe harvest of the OA and the creation of a shallow and wide anastomosis field. PMID:25633907

  12. A global amnesia associated with the specific variant of posterior reversible encephalopathy syndrome (PRES) that developed due to severe preeclampsia and malignant hypertension.

    PubMed

    Borovac, Josip Anđelo; Božić, Joško; Žaja, Nikola; Kolić, Krešimir; Hrboka, Vedran

    2016-04-01

    A case is reported of a 26-year-old primiparous woman in the 32nd week of gestation who presented to the emergency department with the symptoms of a severe headache, nausea and vomiting. The patient was diagnosed with preeclampsia that later progressed to eclampsia. This state was characterized by a sudden onset of a headache and diplopia that advanced to cortical blindness and precipitated significant alterations in mental status, most notable being global amnesia that resolved within 48 h. A post-partum magnetic resonance imaging of the brain in FLAIR mode revealed multiple cortico-subcortical areas of hyperintense signals suggestive of edematous lesions that chiefly involved occipital and parietal lobes with additional atypical manifestations. Such radiologic findings suggested a posterior reversible encephalopathy syndrome variant with the global amnesia as an extraordinary constituent. This unique feature should be acknowledged when treating a preeclamptic or hypertensive patient that exhibits neurological symptomatology and vision disturbances. PMID:27099774

  13. A global amnesia associated with the specific variant of posterior reversible encephalopathy syndrome (PRES) that developed due to severe preeclampsia and malignant hypertension

    PubMed Central

    Borovac, Josip Anđelo; Božić, Joško; Žaja, Nikola; Kolić, Krešimir; Hrboka, Vedran

    2016-01-01

    A case is reported of a 26-year-old primiparous woman in the 32nd week of gestation who presented to the emergency department with the symptoms of a severe headache, nausea and vomiting. The patient was diagnosed with preeclampsia that later progressed to eclampsia. This state was characterized by a sudden onset of a headache and diplopia that advanced to cortical blindness and precipitated significant alterations in mental status, most notable being global amnesia that resolved within 48 h. A post-partum magnetic resonance imaging of the brain in FLAIR mode revealed multiple cortico-subcortical areas of hyperintense signals suggestive of edematous lesions that chiefly involved occipital and parietal lobes with additional atypical manifestations. Such radiologic findings suggested a posterior reversible encephalopathy syndrome variant with the global amnesia as an extraordinary constituent. This unique feature should be acknowledged when treating a preeclamptic or hypertensive patient that exhibits neurological symptomatology and vision disturbances. PMID:27099774

  14. Reversible deactivation of higher-order posterior parietal areas. II. Alterations in response properties of neurons in areas 1 and 2

    PubMed Central

    Goldring, Adam B.; Cooke, Dylan F.; Baldwin, Mary K. L.; Recanzone, Gregg H.; Gordon, Adam G.; Pan, Tingrui; Simon, Scott I.

    2014-01-01

    The role that posterior parietal (PPC) and motor cortices play in modulating neural responses in somatosensory areas 1 and 2 was examined with reversible deactivation by transient cooling. Multiunit recordings from neurons in areas 1 and 2 were collected from six anesthetized adult monkeys (Macaca mulatta) before, during, and after reversible deactivation of areas 5L or 7b or motor cortex (M1/PM), while select locations on the hand and forelimb were stimulated. Response changes were quantified as increases and decreases to stimulus-driven activity relative to baseline and analyzed during three recording epochs: during deactivation (“cool”) and at two time points after deactivation (“rewarm 1,” “rewarm 2”). Although the type of response change observed was variable, for neurons at the recording sites tested >90% exhibited a significant change in response during cooling of 7b while cooling area 5L or M1/PM produced a change in 75% and 64% of sites, respectively. These results suggest that regions in the PPC, and to a lesser extent motor cortex, shape the response characteristics of neurons in areas 1 and 2 and that this kind of feedback modulation is necessary for normal somatosensory processing. Furthermore, this modulation appears to happen on a minute-by-minute basis and may serve as the substrate for phenomena such as somatosensory attention. PMID:25143537

  15. Posterior reversible encephalopathy syndrome in the Intensive Care Unit after liver transplant: a comparison of our experience with the existing literature.

    PubMed

    Lunardi, N; Saraceni, E; Boccagni, P; Segato, M; Bortolato, A; Manara, R; Rossi, S; Ori, C

    2012-07-01

    Posterior reversible encephalopathy syndrome (PRES) is a rare disease characterized by altered mental status, seizures, headache, vomiting and visual disturbances, most often described after transplantation and immunosuppressive therapy. PRES is commonly first diagnosed by the neuroradiologist, rather than the clinician, as it is characterized by very typical magnetic resonance imaging (MRI) features, i.e., hyperintense lesions in the territories of the posterior cerebral artery. Here we report our experience in the Intensive Care Unit (ICU) with a case of tacrolimus-related PRES after liver transplant, presenting with sudden neurological deterioration and diffuse and massive hyperintensities upon brain MRI. Discontinuation of tacrolimus, as prompted by the established literature, permitted the patient to eliminate tacrolimus-associated toxicity, whereas its substitution with everolimus and mycofenolic acid allowed the maintenance of immunosuppression while avoiding acute organ rejection and reducing the dosage of corticosteroids. The lowering of blood pressure with drugs reported in the literature for use in PRES proved to be effective but challenging, requiring the use of multiple drugs and only slowly leading to proper control of hypertensive peaks. Nonetheless, hypertension management and supportive therapy allowed for a complete neurological restitutio ad integrum of the patient. In conclusion, tacrolimus-related brain adverse events need to be promptly recognized, especially during the first months after transplantation. When tacrolimus-related PRES occurs, immunosuppressive therapy may be safely and efficiently switched to everolimus and mycofenolic acid. This strategy may help not only to avoid acute organ rejection but also to reduce the dosage of corticosteroids, which might interfere with proper control of hypertension. PMID:21701444

  16. Long-term consequences of the posterior reversible encephalopathy syndrome in eclampsia and preeclampsia: a review of the obstetric and nonobstetric literature.

    PubMed

    Postma, Ineke R; Slager, Sjoerdtje; Kremer, Hubertus P H; de Groot, Jan Cees; Zeeman, Gerda G

    2014-05-01

    This review summarizes the long-term consequences of the posterior reversible encephalopathy syndrome (PRES) that have been described in the obstetric literature (eclampsia and preeclampsia) and compares these with data from the nonobstetric literature. Preeclampsia is characterized by new-onset hypertension and proteinuria after the 20th week of pregnancy. Neurological symptoms include headache; visual deficits; confusion; seizures; and, in the most severe cases, intracranial hemorrhage. Eclampsia is an acute cerebral complication of preeclampsia, defined as the occurrence of tonic-clonic seizures in pregnant or recently postpartum women. With severe preeclampsia, in conjunction with neurological symptoms, or eclampsia, neuroimaging changes consistent with PRES can be seen. Posterior reversible encephalopathy syndrome is a specific clinicoradiological syndrome presenting with headaches, visual impairment, seizures, and altered mental status. Characteristic neuroimaging features are consistent with cerebral edema predominantly in the parietal and occipital lobes. In addition to preeclampsia/eclampsia, PRES has been associated with various conditions in the nonobstetric population, that is, severe hypertension, transplantation, or autoimmune disease, in combination with immunosuppressive therapy or high-dose chemotherapy for various malignant conditions. Long-term sequelae of both preeclampsia/eclampsia and other PRES-related conditions are poorly described. After eclampsia or preeclampsia, nonspecific white matter lesions may be found on magnetic resonance imaging, which may or may not be related to the PRES episode. Previously (pre)eclamptic women report cognitive failures; however, no neurocognitive impairment has been shown so far. Various nonobstetric PRES-related conditions have been described with long-term neuroimaging abnormalities as well as cognitive problems, epilepsy, or visual impairment. Although no firm conclusions can be drawn because of the

  17. Reversible deactivation of higher-order posterior parietal areas. I. Alterations of receptive field characteristics in early stages of neocortical processing

    PubMed Central

    Cooke, Dylan F.; Goldring, Adam B.; Baldwin, Mary K. L.; Recanzone, Gregg H.; Chen, Arnold; Pan, Tingrui; Simon, Scott I.

    2014-01-01

    Somatosensory processing in the anesthetized macaque monkey was examined by reversibly deactivating posterior parietal areas 5L and 7b and motor/premotor cortex (M1/PM) with microfluidic thermal regulators developed by our laboratories. We examined changes in receptive field size and configuration for neurons in areas 1 and 2 that occurred during and after cooling deactivation. Together the deactivated fields and areas 1 and 2 form part of a network for reaching and grasping in human and nonhuman primates. Cooling area 7b had a dramatic effect on receptive field size for neurons in areas 1 and 2, while cooling area 5 had moderate effects and cooling M1/PM had little effect. Specifically, cooling discrete locations in 7b resulted in expansions of the receptive fields for neurons in areas 1 and 2 that were greater in magnitude and occurred in a higher proportion of sites than similar changes evoked by cooling the other fields. At some sites, the neural receptive field returned to the precooling configuration within 5–22 min of rewarming, but at other sites changes in receptive fields persisted. These results indicate that there are profound top-down influences on sensory processing of early cortical areas in the somatosensory cortex. PMID:25143546

  18. Reversible posterior leukoencephalopathy syndrome following combinatorial cisplatin and pemetrexed therapy for lung cancer in a normotensive patient: A case report and literature review

    PubMed Central

    XIE, CHANGQING; JONES, VOVANTI T.

    2016-01-01

    Reversible posterior leukoencephalopathy syndrome (RPLS) is a rare neurological syndrome of the brain, causing symptoms such as headaches, seizures, altered mental status and visual disturbances. The condition is predominantly associated with hypertension, eclampsia, renal impairment, cytotoxic drugs, immunosuppressive agents and molecular targeted agents, but the precise underlying mechanism of RPLS is not fully understood. The present study describes the case of a 65-year-old female patient with stage IIA non-small cell lung cancer who received cisplatin/pemetrexed treatment at the Leo W. Jenkins Cancer Center. Following 3 cycles of this therapy, the patient was referred to the Emergency Department of Vidant Medical Center with an altered mental status, subsequently presenting with epileptic seizures, a fever and a headache. A neurological examination revealed generalized hyperreflexia and paraparesis, with extensor posturing of the bilateral lower extremities. The lumbar puncture and electroencephalography results were normal, but cranial computed tomography (CT) scans revealed attenuation abnormalities in the bilateral parietal region and the left occipital lobe, with suspected metastasis. Cranial T2-weighted magnetic resonance imaging (MRI) indicated bilateral regions of increased signal intensity in the occipital, temporal and periventricular white matter. The patient was treated with anticonvulsants, steroids and antihypertensive drugs, recovered gradually from the symptoms and regained full consciousness. However, the patient reported residual weakness, presenting with an Eastern Cooperative Oncology Group score of 3, reflective of an inability to independently perform daily activities and self-care. A brain MRI performed 10 days later demonstrated that the subcortical edema had partially subsided. The patient was discharged on day 15 post-admission. A follow-up cranial CT examination 1 month later indicated a partial resolution of the abnormalities. The

  19. Clinical Utility of Computed Tomography and Magnetic Resonance Imaging for Diagnosis of Posterior Reversible Encephalopathy Syndrome after Stem Cell Transplantation in Children and Adolescents.

    PubMed

    Dandoy, Christopher E; Linscott, Luke L; Davies, Stella M; Leach, James L; Myers, Kasiani C; El-Bietar, Javier; Chima, Ranjit S; Pate, Abigail; Nelson, Adam; Wallace, Gregory; Wong, Hector R; Jodele, Sonata

    2015-11-01

    Posterior reversible encephalopathy syndrome (PRES) is a clinical syndrome characterized by vision changes, altered mental status, and seizures, typically caused by an acute rise in blood pressure. PRES has been reported after hematopoietic stem cell transplantation (HSCT) in association with hypertension from calcineurin inhibitors and corticosteroids. The imaging evaluation of PRES after HSCT in children and young adults has not been well described. We performed a retrospective review of all HSCT recipients presenting to the intensive care unit with new neurologic symptoms. A neuroradiologist reviewed all radiologic images and compared computed tomography (CT) versus magnetic resonance imaging (MRI) findings indicative of diagnosis of PRES. Alternative imaging diagnoses explaining the patients' symptoms were also recorded. Fifty-four transplant recipients were admitted to the intensive care unit with new neurologic symptoms. Thirty-nine percent (21 of 54) of subjects had imaging findings consistent with PRES, 24% (13 of 54) had imaging findings consistent with an alternative diagnosis, 9% (5 of 54) had a nonspecific finding, and 28% (15 of 54) had no acute imaging findings. PRES was diagnosed at a median of 49 days (interquartile range, 29 to 94) after HSCT. The presenting symptom for the majority of patients with PRES was seizures (86%), whereas 14% presented with acute encephalopathy. Ninety-five percent of subjects diagnosed with PRES (20 of 21) underwent a head CT as their initial imaging evaluation. CT scan was diagnostic of PRES in 40% (8 of 20). Subsequently, 16 patients underwent brain MRI with 12 additional patients being diagnosed with PRES on MRI. The median time elapsed between negative CT and a positive MRI examination was 20 hours (range, 3.6 hours to 9 days). CT serves as an excellent screening test for acute pathology, such as intracranial hemorrhage; however, it lacks sensitivity for the diagnosis of PRES. Patients with clinical symptoms

  20. [Posterior capsule opacification].

    PubMed

    Milazzo, S; Grenot, M; Benzerroug, M

    2014-12-01

    Posterior capsule opacification (PCO) is the most common complication after cataract surgery, with an incidence of 30%. It tends to be considered a normal event in the natural history of cataract surgery. Better understanding of its pathophysiology and advancement of intraocular lens material and design along with the improvement of phacoemulsification technique have contributed to decrease the incidence of PCO. Although treatment by Nd: YAG laser posterior capsulotomy is quick and non-invasive, the opening of the posterior capsule may be associated with numerous complications. Prevention remains the best measure for controlling this pathology. PMID:25455552

  1. Posterior fossa tumor

    MedlinePlus

    ... of the posterior fossa, it can block the flow of spinal fluid and cause increased pressure on the brain and ... the cancer early. A total blockage in the flow of spinal fluid can be life threatening. If tumors are found ...

  2. Posterior Tibial Tendon Dysfunction

    MedlinePlus

    ... when the posterior tibial tendon becomes inflamed or torn. As a result, the tendon may not be ... repetitive use. Once the tendon becomes inflamed or torn, the arch will slowly fall (collapse) over time. ...

  3. Posterior ankle impingement syndrome.

    PubMed

    Maquirriain, Javier

    2005-10-01

    Posterior ankle impingement syndrome is a clinical disorder characterized by posterior ankle pain that occurs in forced plantar flexion. The pain may be acute as a result of trauma or chronic from repetitive stress. Pathology of the os trigonum-talar process is the most common cause of this syndrome, but it also may result from flexor hallucis longus tenosynovitis, ankle osteochondritis, subtalar joint disease, and fracture. Patients usually report chronic or recurrent posterior ankle pain caused or exacerbated by forced plantar flexion or push-off maneuvers, such as may occur during dancing, kicking, or downhill running. Diagnosis of posterior ankle impingement syndrome is based primarily on clinical history and physical examination. Radiography, scintigraphy, computed tomography, and magnetic resonance imaging depict associated bone and soft-tissue abnormalities. Symptoms typically improve with nonsurgical management, but surgery may be required in refractory cases. PMID:16224109

  4. Bilateral posterior sternoclavicular dislocation.

    PubMed

    Baumann, Matthias; Vogel, Tobias; Weise, Kuno; Muratore, Tim; Trobisch, Per

    2010-07-01

    Posterior sternoclavicular dislocations are a rare injury, representing <5% of all sternoclavicular dislocations and 1 in 1600 shoulder girdle injuries. Proper imaging with computed tomography and prompt diagnosis are essential steps in preventing potentially lethal complications observed in approximately 3% of all posterior sternoclavicular dislocations. Surgical treatment is necessary if closed reduction fails. With the medial clavicular epiphysis being the last to close (between ages 22 and 25), children and adolescents typically present with epiphyseal fractures rather than joint dislocations. If closed reduction fails, open reduction and internal fixation (ORIF) should be considered in fractures, whereas complex reconstructions with tendon graft procedures have been recommended for joint dislocations. This article presents a case of a traumatic bilateral posterior sternoclavicular dislocation due to an epiphyseal fracture in a 15-year-old boy. To our knowledge, this is the first reported case of a bilateral posterior sternoclavicular dislocation. Attempted closed reduction failed with redislocation after 2 days. The patient subsequently required ORIF. This article describes our technique with anterior retraction of the medial clavicle, closure of the posterior periosteum, and ORIF using nonabsorbable sutures. Postoperative shoulder mobilization was started on day 1. At final follow-up, the patient was completely asymptomatic. PMID:20608625

  5. Tibialis Posterior Tendon Entrapment Within Posterior Malleolar Fracture Fragment.

    PubMed

    Fantry, Amanda; Lareau, Craig; Vopat, Bryan; Blankenhorn, Brad

    2016-01-01

    Management of posterior malleolus fractures continues to be controversial, with respect to both need for fixation and fixation methods. Fixation methods include an open posterior approach to the ankle as well as percutaneous reduction and fixation with or without arthroscopy for visualization of the articular surface. Plain radiographs are unreliable in identifying fracture pattern and intraoperative reduction, making arthroscopy a valuable adjunct to posterior malleolus fracture management. In this article, we report a case of tibialis posterior tendon entrapment within a posterior malleolus fracture, as identified by arthroscopy and managed with open reduction. Tibialis posterior tendon entrapment within a posterior malleolus has not been previously reported. Ankle arthroscopy for posterior malleolus fractures provides an opportunity to identify soft-tissue or tendinous entrapment, articular surface reduction, and articular cartilage injuries unlikely to be identified with fluoroscopy alone and should be considered in reduction and fixation of posterior malleolus fractures. PMID:26991573

  6. Estudio de la influencia de la refrigeracion con aire de forma natural e inducida en el comportamiento de instalaciones fotovoltaicas

    NASA Astrophysics Data System (ADS)

    Mazon Hernandez, Rocio

    panels are analysed to compare and select the best configuration. The presented research provides a deep knowledge of how they work as well as information and results for an improvement in future designs of building integrated photovoltaic systems. Este estudio se centra en analizar la influencia negativa de la temperatura en la produccion electrica de paneles fotovoltaicos al estar emplazados sobre cubierta de acero, como sucede en naves industriales y sobre un invernadero. Se estudian diferentes configuraciones que permitan refrigerar los paneles, reduciendo su temperatura y mejorar su rendimiento. Para abordar este problema, se han construido dos instalaciones experimentales, fieles a plantas solares en funcionamiento. Una instalacion engloba dos paneles fotovoltaicos sobre estructura fija al suelo. Uno de los paneles esta integrado sobre una superficie paralela y metalica. Entre ambas superficies existe un espacio que posibilita circular aire, permitiendo refrigerar el panel por conveccion natural, o conveccion forzada impulsando el aire con un ventilador. El otro panel, libre por su cara posterior y se ha considerado de referencia. Se ha estudiado el comportamiento del panel integrado sobre cubierta para diferentes secciones de aire y velocidades inducidas, comparandolo con el panel de referencia. Se ha desarrollado un modelo experimental que nos permite determinar la temperatura del panel en funcion de las variables que influyen en su refrigeracion. Adicionalmente, se han analizado los datos de una planta solar en funcionamiento, con paneles de igual caracteristicas, obteniendo correlaciones entre la temperatura del panel y las variables electricas y comparandolos con las obtenidas en la instalacion experimental. La segunda instalacion experimental reproduce parte de una instalacion solar sobre un invernadero, formada por cuatro paneles fotovoltaicos colocados sobre el plastico del invernadero, existiendo un canal divergente entre ambas superficies. Se estudia la

  7. Subspecialization in the human posterior medial cortex

    PubMed Central

    Bzdok, Danilo; Heeger, Adrian; Langner, Robert; Laird, Angela R.; Fox, Peter T.; Palomero-Gallagher, Nicola; Vogt, Brent A.; Zilles, Karl; Eickhoff, Simon B.

    2014-01-01

    The posterior medial cortex (PMC) is particularly poorly understood. Its neural activity changes have been related to highly disparate mental processes. We therefore investigated PMC properties with a data-driven exploratory approach. First, we subdivided the PMC by whole-brain coactivation profiles. Second, functional connectivity of the ensuing PMC regions was compared by task-constrained meta-analytic coactivation mapping (MACM) and task-unconstrained resting-state correlations (RSFC). Third, PMC regions were functionally described by forward/reverse functional inference. A precuneal cluster was mostly connected to the intraparietal sulcus, frontal eye fields, and right temporo-parietal junction; associated with attention and motor tasks. A ventral posterior cingulate cortex (PCC) cluster was mostly connected to the ventromedial prefrontal cortex and middle left inferior parietal cortex (IPC); associated with facial appraisal and language tasks. A dorsal PCC cluster was mostly connected to the dorsomedial prefrontal cortex, anterior/posterior IPC, posterior midcingulate cortex, and left dorsolateral prefrontal cortex; associated with delay discounting. A cluster in the retrosplenial cortex was mostly connected to the anterior thalamus and hippocampus. Furthermore, all PMC clusters were congruently coupled with the default mode network according to task-constrained but not task-unconstrained connectivity. We thus identified distinct regions in the PMC and characterized their neural networks and functional implications. PMID:25462801

  8. Posterior Tibial Tendon Transfer.

    PubMed

    Shane, Amber M; Reeves, Christopher L; Cameron, Jordan D; Vazales, Ryan

    2016-01-01

    When performed correctly with the right patient population, a tibialis posterior muscle/tendon transfer is an effective procedure. Many different methods have been established for fixating the tendon, each of which has its' own indications. Passing through the interosseous membrane is the preferred and recommended method and should be used unless this is not possible. Good surgical planning based on patient needs and expectations, along with excellent postoperative care including early range of motion and physical therapy minimizes risk of complications and allows for the optimal outcome to be achieved. PMID:26590722

  9. Posterior Urethral Strictures

    PubMed Central

    Gelman, Joel; Wisenbaugh, Eric S.

    2015-01-01

    Pelvic fracture urethral injuries are typically partial and more often complete disruptions of the most proximal bulbar and distal membranous urethra. Emergency management includes suprapubic tube placement. Subsequent primary realignment to place a urethral catheter remains a controversial topic, but what is not controversial is that when there is the development of a stricture (which is usually obliterative with a distraction defect) after suprapubic tube placement or urethral catheter removal, the standard of care is delayed urethral reconstruction with excision and primary anastomosis. This paper reviews the management of patients who suffer pelvic fracture urethral injuries and the techniques of preoperative urethral imaging and subsequent posterior urethroplasty. PMID:26691883

  10. Posterior Urethral Strictures.

    PubMed

    Gelman, Joel; Wisenbaugh, Eric S

    2015-01-01

    Pelvic fracture urethral injuries are typically partial and more often complete disruptions of the most proximal bulbar and distal membranous urethra. Emergency management includes suprapubic tube placement. Subsequent primary realignment to place a urethral catheter remains a controversial topic, but what is not controversial is that when there is the development of a stricture (which is usually obliterative with a distraction defect) after suprapubic tube placement or urethral catheter removal, the standard of care is delayed urethral reconstruction with excision and primary anastomosis. This paper reviews the management of patients who suffer pelvic fracture urethral injuries and the techniques of preoperative urethral imaging and subsequent posterior urethroplasty. PMID:26691883

  11. Posterior Cortical Atrophy

    PubMed Central

    Crutch, Sebastian J; Lehmann, Manja; Schott, Jonathan M; Rabinovici, Gil D; Rossor, Martin N; Fox, Nick C

    2013-01-01

    Posterior cortical atrophy (PCA) is a neurodegenerative syndrome that is characterized by a progressive decline in visuospatial, visuoperceptual, literacy and praxic skills. The progressive neurodegeneration affecting parietal, occipital and occipito-temporal cortices which underlies PCA is attributable to Alzheimer's disease (AD) in the majority of patients. However, alternative underlying aetiologies including Dementia with Lewy Bodies (DLB), corticobasal degeneration (CBD) and prion disease have also been identified, and not all PCA patients have atrophy on clinical imaging. This heterogeneity has led to diagnostic and terminological inconsistencies, caused difficulty comparing studies from different centres, and limited the generalizability of clinical trials and investigations of factors driving phenotypic variability. Significant challenges remain in identifying the factors associated with both the selective vulnerability of posterior cortical regions and the young age of onset seen in PCA. Greater awareness of the syndrome and agreement over the correspondence between syndrome-and disease-level classifications are required in order to improve diagnostic accuracy, research study design and clinical management. PMID:22265212

  12. Novel posterior fixation keratoprosthesis

    NASA Astrophysics Data System (ADS)

    Lacombe, Emmanuel

    1992-08-01

    The keratoprosthesis is the last solution for corneally blind patients that cannot benefit from corneal transplants. Keratoprostheses that have been designed to be affixed anteriorly usually necessitate multi-step surgical procedures and are continuously subjected to the extrusion forces generated by the positive intraocular pressure; therefore, clinical results in patients prove inconsistent. We proposed a novel keratoprosthesis concept that utilizes posterior corneal fixation which `a priori' minimizes the risk of aqueous leakage and expulsion. This prosthesis is implanted in a single procedure thereby reducing the number of surgical complications normally associated with anterior fixation devices. In addition, its novel design makes this keratoprosthesis implantable in phakic eyes. With an average follow-up of 13 months (range 3 to 25 months), our results on 21 cases are encouraging. Half of the keratoprostheses were implanted in severe burn cases, with the remainder in cases of pseudo- pemphigus. Good visual results and cosmetic appearance were obtained in 14 of 21 eyes.

  13. Estudio de la influencia de la refrigeracion con aire de forma natural e inducida en el comportamiento de instalaciones fotovoltaicas

    NASA Astrophysics Data System (ADS)

    Mazon Hernandez, Rocio

    panels are analysed to compare and select the best configuration. The presented research provides a deep knowledge of how they work as well as information and results for an improvement in future designs of building integrated photovoltaic systems. Este estudio se centra en analizar la influencia negativa de la temperatura en la produccion electrica de paneles fotovoltaicos al estar emplazados sobre cubierta de acero, como sucede en naves industriales y sobre un invernadero. Se estudian diferentes configuraciones que permitan refrigerar los paneles, reduciendo su temperatura y mejorar su rendimiento. Para abordar este problema, se han construido dos instalaciones experimentales, fieles a plantas solares en funcionamiento. Una instalacion engloba dos paneles fotovoltaicos sobre estructura fija al suelo. Uno de los paneles esta integrado sobre una superficie paralela y metalica. Entre ambas superficies existe un espacio que posibilita circular aire, permitiendo refrigerar el panel por conveccion natural, o conveccion forzada impulsando el aire con un ventilador. El otro panel, libre por su cara posterior y se ha considerado de referencia. Se ha estudiado el comportamiento del panel integrado sobre cubierta para diferentes secciones de aire y velocidades inducidas, comparandolo con el panel de referencia. Se ha desarrollado un modelo experimental que nos permite determinar la temperatura del panel en funcion de las variables que influyen en su refrigeracion. Adicionalmente, se han analizado los datos de una planta solar en funcionamiento, con paneles de igual caracteristicas, obteniendo correlaciones entre la temperatura del panel y las variables electricas y comparandolos con las obtenidas en la instalacion experimental. La segunda instalacion experimental reproduce parte de una instalacion solar sobre un invernadero, formada por cuatro paneles fotovoltaicos colocados sobre el plastico del invernadero, existiendo un canal divergente entre ambas superficies. Se estudia la

  14. Gossypiboma mimicking posterior urethral stricture

    PubMed Central

    Kumar, Bindey; Kumar, Prem; Sinha, Sanjay Kumar; Sinha, Neelam; Hasan, Zaheer; Thakur, Vinit Kumar; Anand, Utpal; Priyadarshi, Rajiv Nayan; Mandal, Manish

    2013-01-01

    INTRODUCTION Foreign bodies in the urogenital tract are not uncommon. Hairpins, glass rods, umbilical tapes, ball point pen are described in lower urogenital tract. Retained gauze piece (gossypiboma) in posterior urethra may cause diagnostic dilemma. Symptoms and investigations may mimic stricture of posterior urethra. PRESENTATION OF CASE Two cases of retained gauze pieces in the urethra are described here. The micturating cystourethrogram was suggestive of posterior urethral stricture. DISCUSSION Two cases described here had retained gauze piece as a cause of filling defect and abnormal appearance in the micturating cystourethrogram. Gossypiboma may be a possibility where posterior urethral stricture are seen after previous surgery in paediatric age group. CONCLUSION In the setting of previous urogenital surgery gossypiboma should be kept in the differential diagnosis where posterior urethral stricture are seen in the paediatric age group. PMID:23500749

  15. Endothelin: A novel peptide in the posterior pituitary system

    SciTech Connect

    Yoshizawa, Toshihiro; Kanazawa, Ichiro; Shinmi, Osamu; Kimura, Sadao; Yanagisawa, Masashi; Masaki, Tomoh; Uchiyama, Yasuo ); Giaid, A.; Gibson, S.J.; Polak, J.M. )

    1990-01-26

    Endothelin (ET), originally characterized as a 21-residue vasoconstrictor peptide from endothelial cells, is present in the porcine spinal cord and may act as a neuropeptide. Endothelin-like immunoreactivity has now been demonstrated by immunohistochemistry in the paraventricular and supraoptic nuclear neurons and their terminals in the posterior pituitary of the pig and the rat. The presence of ET in the porcine hypothalamus was confirmed by reversed-phase high-pressure liquid chromatography and radioimmunoassay. Moreover, in situ hybridization demonstrated ET messenger RNA in porcine paraventricular nuclear neurons. Endothelin-like immunoreactive products in the posterior pituitary of the rat were depleted by water deprivation, suggesting a release of ET under physiological conditions. These findings indicate that ET is synthesized in the posterior pituitary system and may be involved in neurosecretory functions.

  16. Estimation and uncertainty of reversible Markov models

    NASA Astrophysics Data System (ADS)

    Trendelkamp-Schroer, Benjamin; Wu, Hao; Paul, Fabian; Noé, Frank

    2015-11-01

    Reversibility is a key concept in Markov models and master-equation models of molecular kinetics. The analysis and interpretation of the transition matrix encoding the kinetic properties of the model rely heavily on the reversibility property. The estimation of a reversible transition matrix from simulation data is, therefore, crucial to the successful application of the previously developed theory. In this work, we discuss methods for the maximum likelihood estimation of transition matrices from finite simulation data and present a new algorithm for the estimation if reversibility with respect to a given stationary vector is desired. We also develop new methods for the Bayesian posterior inference of reversible transition matrices with and without given stationary vector taking into account the need for a suitable prior distribution preserving the meta-stable features of the observed process during posterior inference. All algorithms here are implemented in the PyEMMA software — http://pyemma.org — as of version 2.0.

  17. Posterior polar cataract: A review

    PubMed Central

    Kalantan, Hatem

    2011-01-01

    Posterior polar cataract is a rare form of congenital cataract. It is usually inherited as an autosomal dominant disease, yet it can be sporadic. Five genes have been attributed to the formation of this disease. It is highly associated with complications during surgery, such as posterior capsule rupture and nucleus drop. The reason for this high complication rate is the strong adherence of the opacity to the weak posterior capsule. Different surgical strategies were described for the handling of this challenging entity, most of which emphasized the need for gentle maneuvering in dealing with these cases. It has a unique clinical appearance that should not be missed in order to anticipate, avoid, and minimize the impact of the complications associated with it. PMID:23960967

  18. Rethinking "posterior" tongue-tie.

    PubMed

    Douglas, Pamela Sylvia

    2013-12-01

    Currently, many clinicians who help with breastfeeding problems are diagnosing "posterior" tongue-tie in infants and performing or referring for frenotomy. In this "Speaking Out" article, I argue that the diagnosis of "posterior" tongue-tie has successfully raised awareness of the importance of impaired tongue function in breastfeeding difficulty. However, the diagnosis of "posterior" tongue-tie also applies a reductionist, medicalized theoretical frame to the complex problem of impaired tongue function, risking unintended outcomes. Impaired tongue function arises out of multiple interacting and co-evolving factors, including the interplay between social behaviors concerning breastfeeding and mother-infant biology. Consideration of theoretical frames is vital if we are to build an evidence base through efficient use of the scarce resources available for clinical breastfeeding research and minimize unintended outcomes. PMID:24143939

  19. Posterior Tibial Tendon Dysfunction (PTTD)

    MedlinePlus

    ... ACFAS | Información en Español Advanced Search Home » Foot & Ankle Conditions » Posterior Tibial Tendon Dysfunction (PTTD) Text Size ... the arch, and an inward rolling of the ankle. As the condition progresses, the symptoms will change. ...

  20. Stereolithography for Posterior Fossa Cranioplasty

    PubMed Central

    Agner, Celso; Dujovny, Manuel; Evenhouse, Raymond; Charbel, Fady T.; Sadler, Lewis

    1998-01-01

    Posterior fossa cranioplasty has been suggested for improvement of neurological symptoms following craniectomy. However, there is no particular recommendation in the literature about techniques for prosthesis manufacture and implantation. We report our experience using rapid prototyping technology and stereolithography for pre-surgical implant design and production of cranioplasties. ImagesFigure 1Figure 2Figure 3Figure 4Figure 5 PMID:17171056

  1. Posterior cruciate ligament of the knee (image)

    MedlinePlus

    The posterior cruciate ligament (PCL) is a powerful ligament extending from the top-rear surface of the tibia to the bottom-front surface of the femur. The ligament prevents the knee joint from posterior instability.

  2. Bilateral posterior cerebral artery infarction.

    PubMed

    Ryan, Davinia; Murphy, Sinead M; Hennessey, Michael J

    2010-01-01

    We report the case of a 70-year-old man who presented with short-term memory impairment and a homonymous left inferior quadrantanopia secondary to simultaneous bilateral posterior cerebral artery (PCA) territory infarction. As in more than a quarter of cases of PCA infarction, no aetiological cause was identified. Unlike the transient nature of symptoms in some cases following unilateral infarction, his deficits persisted on 2-month follow-up. PMID:22798298

  3. Spinal hemianesthesia: Unilateral and posterior

    PubMed Central

    Imbelloni, Luiz Eduardo

    2014-01-01

    The injection of a non-isobaric local anesthetic should induce a unilateral spinal anesthesia in patients in a lateral decubitus position. The posterior spinal hemianesthesia only be obtained with hypobaric solutions injected in the jackknife position. The most important factors to be considered when performing a spinal hemianesthesia are: type and gauge of the needle, density of the local anesthetic relative to the CSF, position of the patient, speed of administration of the solution, time of stay in position, and dose/concentration/volume of the anesthetic solution. The distance between the spinal roots on the right-left sides and anterior-posterior is, approximately, 10-15 mm. This distance allows performing unilateral spinal anesthesia or posterior spinal anesthesia. The great advantage of obtaining spinal hemianesthesia is the reduction of cardiovascular changes. Likewise, both the dorsal and unilateral sensory block predominates in relation to the motor block. Because of the numerous advantages of producing spinal hemianesthesia, anesthesiologists should apply this technique more often. This review considers the factors which are relevant, plausible and proven to obtain spinal hemianesthesia. PMID:25886320

  4. Evaluation of arthroscopic treatment of posterior shoulder instability

    PubMed Central

    Garcia, José Carlos; Maia, Lucas Russo; Fonseca, Juliano Rocha; Zabeu, José Luís Amim; Garcia, Jesely Pereira Myrrha

    2015-01-01

    OBJECTIVE: To provide data for the analysis of arthroscopy as a method of surgical treatment for shoulder and discuss its actual indications and preliminary results. METHODS: We evaluated 15 patients submitted to reverse Bankart arthroscopic surgery. We used the UCLA (University of California at Los Angeles) score to measure the results before surgery and 12 months thereafter. RESULTS: The average UCLA score changed from 26.67±0.25 (SD 0.97) before surgery to 34.20±0.53 (SD 2.04) after surgery. The effectiveness of surgery was 93%. In five cases loose bodies were found. A patient undergoing remplissage was evaluated separately. The data did not change after 24 months post-surgery. CONCLUSION: The arthroscopic treatment of posterior shoulder instability and posterior dislocation of the shoulder has been proved feasible and results in our series followed the same trends as in the literature. Level of Evidence III, Transversal Retrospective Study. PMID:26207089

  5. Reversible Sterilization

    ERIC Educational Resources Information Center

    Largey, Gale

    1977-01-01

    Notes that difficult questions arise concerning the use of sterilization for alleged eugenic and euthenic purposes. Thus, how reversible sterilization will be used with relation to the poor, mentally ill, mentally retarded, criminals, and minors, is questioned. (Author/AM)

  6. Isolated posterior cruciate ligament calcification.

    PubMed

    Koukoulias, Nikolaos E; Papastergiou, Stergios G

    2011-01-01

    The authors present a case of calcified posterior cruciate ligament (PCL). A 61-year-old female presented in our department reporting 12 months history of knee pain that was getting worse during the night. The patient was under medication for epileptic seizure, osteoporosis and hyperthyroidism. X-rays demonstrated calcification of the PCL. CT and MRI excluded any other intra-articular and extra-articular pathology. Arthroscopic debridement of the calcium deposits was performed and the symptoms resolved immediately, while the postoperative x-rays were normal. Histological examination confirmed the calcium nature of the lesion. Two years postoperatively the patient remains asymptomatic. PMID:22669889

  7. Isolated posterior cruciate ligament calcification

    PubMed Central

    Koukoulias, Nikolaos E; Papastergiou, Stergios G

    2011-01-01

    The authors present a case of calcified posterior cruciate ligament (PCL). A 61-year-old female presented in our department reporting 12 months history of knee pain that was getting worse during the night. The patient was under medication for epileptic seizure, osteoporosis and hyperthyroidism. X-rays demonstrated calcification of the PCL. CT and MRI excluded any other intra-articular and extra-articular pathology. Arthroscopic debridement of the calcium deposits was performed and the symptoms resolved immediately, while the postoperative x-rays were normal. Histological examination confirmed the calcium nature of the lesion. Two years postoperatively the patient remains asymptomatic. PMID:22669889

  8. Posterior ankyloglossia: a case report.

    PubMed

    Chu, Michael W; Bloom, David C

    2009-06-01

    Ankyloglossia, or tongue-tie, refers to an abnormally short lingual frenulum. Ankyloglossia is a recognized but poorly defined condition and has been reported to cause feeding difficulties, dysarthria, dyspnea, and social or mechanical problems. In infants, the most concerning symptoms are feeding difficulties and inability to breastfeed. While a recent trend toward breastfeeding has brought frenulectomy back into favor, the literature regarding treatment remains inconclusive. We report a case of posterior ankyloglossia with anterior mucosal hooding and a simple, safe, and effective way to treat it to improve breastfeeding. PMID:19303646

  9. Reversible Cardiomyopathies

    PubMed Central

    Patel, Harsh; Madanieh, Raef; Kosmas, Constantine E; Vatti, Satya K; Vittorio, Timothy J

    2015-01-01

    Cardiomyopathies (CMs) have many etiological factors that can result in severe structural and functional dysregulation. Fortunately, there are several potentially reversible CMs that are known to improve when the root etiological factor is addressed. In this article, we discuss several of these reversible CMs, including tachycardia-induced, peripartum, inflammatory, hyperthyroidism, Takotsubo, and chronic illness–induced CMs. Our discussion also includes a review on their respective pathophysiology, as well as possible management solutions. PMID:26052233

  10. New method of posterior scallop augmentation for ischemic mitral regurgitation.

    PubMed

    Aoki, Masakazu; Ito, Toshiaki

    2015-03-01

    We report a new method of posterior middle scallop (P2) augmentation for ischemic mitral regurgitation to achieve deep coaptation. First, P2 was divided straight at the center and partially detached from the annulus in a reverse T shape. A narrow pentagon-shaped section of pericardium was sutured to the divided P2 and annular defect. The tip of the pentagon was attached directly to the papillary muscle, thus creating a very large P2 scallop. A standard-sized ring was placed. We adopted this technique in 2 patients with advanced ischemic cardiomyopathy, and no mitral regurgitation was observed during a 1-year follow-up. PMID:25742844

  11. Longevity of Posterior Composite Restorations

    PubMed Central

    Opdam, N.J.M.; van de Sande, F.H.; Bronkhorst, E.; Cenci, M.S.; Bottenberg, P.; Pallesen, U.; Gaengler, P.; Lindberg, A.; Huysmans, M.C.D.N.J.M.; van Dijken, J.W.

    2014-01-01

    The aim of this meta-analysis, based on individual participant data from several studies, was to investigate the influence of patient-, materials-, and tooth-related variables on the survival of posterior resin composite restorations. Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we conducted a search resulting in 12 longitudinal studies of direct posterior resin composite restorations with at least 5 years’ follow-up. Original datasets were still available, including placement/failure/censoring of restorations, restored surfaces, materials used, reasons for clinical failure, and caries-risk status. A database including all restorations was constructed, and a multivariate Cox regression method was used to analyze variables of interest [patient (age; gender; caries-risk status), jaw (upper; lower), number of restored surfaces, resin composite and adhesive materials, and use of glass-ionomer cement as base/liner (present or absent)]. The hazard ratios with respective 95% confidence intervals were determined, and annual failure rates were calculated for subgroups. Of all restorations, 2,816 (2,585 Class II and 231 Class I) were included in the analysis, of which 569 failed during the observation period. Main reasons for failure were caries and fracture. The regression analyses showed a significantly higher risk of failure for restorations in high-caries-risk individuals and those with a higher number of restored surfaces. PMID:25048250

  12. Huge interparietal posterior fontanel meningohydroencephalocele

    PubMed Central

    Dos Santos, Manuel Filipe Dias; de Santa Barbara, Rita de Cassia

    2015-01-01

    Congenital encephalocele is a neural tube defect characterized by a sac-like protrusion of the brain, meninges, and other intracranial structures through the skull, which is caused by an embryonic development abnormality. The most common location is at the occipital bone, and its incidence varies according to different world regions. We report a case of an 1-month and 7-day-old male child with a huge interparietal-posterior fontanel meningohydroencephalocele, a rare occurrence. Physical examination and volumetric computed tomography were diagnostic. The encephalocele was surgically resected. Intradural and extradural approaches were performed; the bone defect was not primarily closed. Two days after surgery, the patient developed hydrocephaly requiring ventriculoperitoneal shunting. The surgical treatment of the meningohydroencephalocele of the interparietal-posterior fontanel may be accompanied by technical challenges and followed by complications due to the presence of large blood vessels under the overlying skin. In these cases, huge sacs herniate through large bone defects including meninges, brain, and blood vessels. The latter present communication with the superior sagittal sinus and ventricular system. A favorable surgical outcome generally follows an accurate strategy taking into account individual features of the lesion. PMID:26484324

  13. Minimally invasive posterior hamstring harvest.

    PubMed

    Wilson, Trent J; Lubowitz, James H

    2013-01-01

    Autogenous hamstring harvesting for knee ligament reconstruction is a well-established standard. Minimally invasive posterior hamstring harvest is a simple, efficient, reproducible technique for harvest of the semitendinosus or gracilis tendon or both medial hamstring tendons. A 2- to 3-cm longitudinal incision from the popliteal crease proximally, in line with the semitendinosus tendon, is sufficient. The deep fascia is bluntly penetrated, and the tendon or tendons are identified. Adhesions are dissected. Then, an open tendon stripper is used to release the tendon or tendons proximally; a closed, sharp tendon stripper is used to release the tendon or tendons from the pes. Layered, absorbable skin closure is performed, and the skin is covered with a skin sealant, bolster dressing, and plastic adhesive bandage for 2 weeks. PMID:24266003

  14. Primary Burkitt lymphoma in the posterior mediastinum.

    PubMed

    Chaari, Zied; Charfi, Slim; Hentati, Abdessalem; Ayadi, Ines; Abid, Hanene; Frikha, Imed

    2015-11-01

    A 13-year-old boy was admitted to our hospital with complaints of posterior chest pain and dyspnea. Computed tomography and magnetic resonance imaging of the chest revealed a mass in the posterior mediastinum, extending from T8 to T11 with intraspinal involvement. A percutaneous core needle biopsy confirmed the diagnosis of Burkitt lymphoma. He was treated according to the Lymphoma Malignancy B protocol 2001 arm C3, but he presented with liver and brain relapses and died 7.5 months after admission. Although lymphoma is rarely localized in the posterior mediastinum, it should be considered in the differential diagnosis of posterior mediastinal masses in children. PMID:26038605

  15. Pseudoaneurysm of the Posterior Tibial Artery After Posterior Tibial Tendon Transfer.

    PubMed

    Elabdi, Monsef; Roukhsi, Redouane; Tijani, Youssef; Chtata, Hassan; Jaafar, Abdeloihab

    2016-01-01

    Pseudoaneurysm of the posterior tibial artery is an uncommon condition that, left untreated, can lead to hemorrhage, thrombosis, or emboli. We present the case of a 54-year-old male who developed pseudoaneurysm of the posterior tibial artery 4 months after undergoing tibialis posterior tendon transfer for management of peroneal nerve palsy, which had developed as a complication of hip arthroplasty. PMID:26972754

  16. Posterior Cervical Foraminotomy: Indications, Technique, and Outcomes.

    PubMed

    Dodwad, Shah-Jahan M; Dodwad, Shah-Nawaz M; Prasarn, Mark L; Savage, Jason W; Patel, Alpesh A; Hsu, Wellington K

    2016-06-01

    Cervical radiculopathy presents with upper extremity pain, decreased sensation, and decreased strength caused by irritation of specific nerve root(s). After failure of conservative management, surgical options include anterior cervical decompression and fusion, disk arthroplasty, and posterior cervical foraminotomy. In this review, we discuss indications, techniques, and outcomes of posterior cervical laminoforaminotomy. PMID:27187617

  17. Consistently inconsistent, the posterior vaginal wall.

    PubMed

    Hale, Douglass S; Fenner, Dee

    2016-03-01

    Posterior vaginal wall prolapse is one of the most common prolapses encountered by gynecological surgeons. What appears to be a straightforward condition to diagnose and treat surgically for physicians has proven to be frustratingly unpredictable with regard to symptom relief for patients. Functional disorders such as dyssynergic defecation and constipation are often attributed to posterior vaginal wall prolapse. Little scientific evidence supports this assumption, emphasizing that structure and function are not synonymous when treating posterior vaginal wall prolapse. Rectoceles, enteroceles, sigmoidoceles, peritoneoceles, rectal and intraanal intussusception, rectal prolapse, and descending perineal syndrome are all conditions that have an impact on the posterior vaginal wall. All too often these different anatomic conditions are treated with the same surgical approach, addressing a posterior vaginal wall bulge with a traditional posterior colporrhaphy. Studies that examine the correlation between stage of posterior wall prolapse and patient symptoms have failed to reliably do so. Surgical outcomes measured by prolapse staging appear successful, yet patient expectations are often not met. As increasing attention is being placed on patient satisfaction outcomes concerning surgical treatments, this fact will need to be addressed. Surgeons will have to clearly communicate what can and what cannot be expected with surgical repair of posterior vaginal wall prolapse. PMID:26348375

  18. Vasectomy reversal.

    PubMed

    Belker, A M

    1987-02-01

    A vasovasostomy may be performed on an outpatient basis with local anesthesia, but also may be performed on an outpatient basis with epidural or general anesthesia. Local anesthesia is preferred by most of my patients, the majority of whom choose this technique. With proper preoperative and intraoperative sedation, patients sleep lightly through most of the procedure. Because of the length of time often required for bilateral microsurgical vasoepididymostomy, epidural or general anesthesia and overnight hospitalization are usually necessary. Factors influencing the preoperative choice for vasovasostomy or vasoepididymostomy in patients undergoing vasectomy reversal are considered. The preoperative planned choice of vasovasostomy or vasoepididymostomy for patients having vasectomy reversal described herein does not have the support of all urologists who regularly perform these procedures. My present approach has evolved as the data reported in Tables 1 and 2 have become available, but it may change as new information is evaluated. However, it offers a logical method for planning choices of anesthesia and inpatient or outpatient status for patients undergoing vasectomy reversal procedures. PMID:3811050

  19. The management of bilateral posterior fracture dislocations of the shoulder: a case series illustrating management options

    PubMed Central

    Robinson, Peter W; Packham, Iain; Crowther, Mark

    2016-01-01

    Background Although dislocation of the shoulder is a relatively common event, the overwhelming majority of injuries are anterior. Posterior shoulder dislocation is more uncommon, comprising between 3% and 5% of all shoulder dislocations. One percent of shoulder dislocations involve a fracture, whereas only 0.9% of the 1500 cases reported by Neer (J Bone Joint Surg Am 1970; 52:1077–89; J Bone Joint Surg Am 1970; 52:1090–103) concerned posterior fracture dislocations. Bilateral posterior fracture dislocation is an even rarer event, comprising just 5% of all posterior fracture dislocations. Given the rarity and relative poor outcome often observed after these severe injuries, it is important that upper limb function is optimized. Methods Bilateral posterior fracture dislocations of the shoulder pose a difficult clinical challenge that requires careful management planning. To date, there have been three isolated case reports of using contralateral osteochondral humeral autograft and hemiarthroplasty. We report our experiences and clinical outcomes in managing four such cases using a variety and combination of treatments, including the first reported use of reverse shoulder arthroplasty with contralateral osteochondral humeral autografting. Results Shoulders reconstructed with humeral autograft demonstrated superior Oxford Shoulder Scores and an improved range of motion, as measured by a markerless machine vision system, compared to hemiarthroplasty. Conclusions Our results support the use of a contralateral humeral autograft in bilateral posterior shoulder fracture dislocation.

  20. Congenital basis of posterior fossa anomalies

    PubMed Central

    Cotes, Claudia; Bonfante, Eliana; Lazor, Jillian; Jadhav, Siddharth; Caldas, Maria; Swischuk, Leonard

    2015-01-01

    The classification of posterior fossa congenital anomalies has been a controversial topic. Advances in genetics and imaging have allowed a better understanding of the embryologic development of these abnormalities. A new classification schema correlates the embryologic, morphologic, and genetic bases of these anomalies in order to better distinguish and describe them. Although they provide a better understanding of the clinical aspects and genetics of these disorders, it is crucial for the radiologist to be able to diagnose the congenital posterior fossa anomalies based on their morphology, since neuroimaging is usually the initial step when these disorders are suspected. We divide the most common posterior fossa congenital anomalies into two groups: 1) hindbrain malformations, including diseases with cerebellar or vermian agenesis, aplasia or hypoplasia and cystic posterior fossa anomalies; and 2) cranial vault malformations. In addition, we will review the embryologic development of the posterior fossa and, from the perspective of embryonic development, will describe the imaging appearance of congenital posterior fossa anomalies. Knowledge of the developmental bases of these malformations facilitates detection of the morphological changes identified on imaging, allowing accurate differentiation and diagnosis of congenital posterior fossa anomalies. PMID:26246090

  1. Posterior Thigh Flap Pedicled on the Cutaneous Vessels Arising From the Popliteo-posterior Intermediate Artery: A Report of 5 Cases.

    PubMed

    Sun, Xi-Guang; Gong, Xu; Song, Liang-Song; Cui, Jian-Li; Yu, Xin; Liu, Bin; Lu, Lai-Jin

    2016-08-01

    Surgical repair of soft tissue defects of the knee and leg remains challenging. Using a case study approach, the anatomy of the popliteo-posterior intermediate cutaneous artery was examined, and a reverse island flap method was developed and implemented. After obtaining informed consent, 5 patients (1 woman, 4 men, age range 31 to 57 years) underwent the experimental use of a reverse island flap with a posterior thigh flap pedicled on the cutaneous vessels arising from the popliteo-posterior intermediate artery to repair soft-tissue defects of the knee and leg. The defects were caused by burned skin below the knee (n = 1), progressive skin necrosis in the knee after fracture surgery (n = 2), and skin infections associated with diabetes mellitus (n = 2). Skin defect sizes ranged from 15 cm x 5 cm to 30 cm x 12 cm. These large defects did not heal spontaneously; wound duration ranged from 1 week to 1 year, and all patients had refused defect repair with free flaps. Patients received posterior thigh flaps pedicled on the popliteo-posterior intermediate artery with areas ranging from 17 cm x 6 cm to 25 cm x 12 cm. All patients were treated with antibiotics and local dressings (iodoform and alcohol) changed daily post surgery, and blood supply was monitored by assessing the texture and color of the flap and venous regurgitation (ie, vein drainage disturbance). Four (4) of the five flaps survived completely. In 1 patient, partial survival of the flap, which had a good blood supply despite a venous circulation disorder, occurred: in this case, complete survival was achieved after treatment with a retrograde fascial flap and skin grafting. The appearance and texture of all flaps were satisfactory (ie, patients underwent only 1 operation, healing time was approximately 2 weeks, flap quality was close to normal skin, the donor site closed directly, and the shape and function of the knee and leg recovered well). No donor site abnormality was observed, and no postsurgical

  2. Posterior cruciate ligament (PCL) injury - aftercare

    MedlinePlus

    ... posterior cruciate ligament (PCL) is located inside your knee joint and connects the bones of your upper and ... such as a knee dislocation , you will need knee surgery to repair the joint. For milder injuries, you may not need surgery. ...

  3. Cryptorchidism in boys with posterior urethral valves.

    PubMed

    Krueger, R P; Hardy, B E; Churchill, B M

    1980-07-01

    A review of 207 male children with poterior urethral valves revealed an over-all incidence of cryptorchidism of 12 per cent. This association of cryptorchidism in boys with posterior urethral valves has not been described previously. PMID:6106069

  4. Posterior Hip Pain in an Athletic Population

    PubMed Central

    Frank, Rachel M.; Slabaugh, Mark A.; Grumet, Robert C.; Virkus, Walter W.; Bush-Joseph, Charles A.; Nho, Shane J.

    2010-01-01

    Context: Posterior hip pain is a relatively uncommon but increasingly recognized complaint in the orthopaedic community. Patient complaints and presentations are often vague or nonspecific, making diagnosis and subsequent treatment decisions difficult. The purposes of this article are to review the anatomy and pathophysiology related to posterior hip pain in the athletic patient population. Evidence Acquisition: Data were collected through a thorough review of the literature via a MEDLINE search of all relevant articles between 1980 and 2010. Results: Many patients who complain of posterior hip pain actually have pain referred from another part of the body—notably, the lumbar spine or sacroiliac joint. Treatment options for posterior hip pain are typically nonoperative; however, surgery is warranted in some cases. Conclusions: Recent advancements in the understanding of hip anatomy, pathophysiology, and treatment options have enabled physicians to better diagnosis athletic hip injuries and select patients for appropriate treatment. PMID:23015944

  5. Oval capsulorhexis for phacoemulsification in posterior polar cataract with preexisting posterior capsule rupture.

    PubMed

    Singh, Kiranjit; Mittal, Vikas; Kaur, Harmit

    2011-07-01

    We describe use of an oval capsulorhexis rather than the conventional circular capsulorhexis for phacoemulsification in posterior polar cataract with preexisting posterior capsule rupture. An oval capsulorhexis minimizes the turbulence in the capsular bag by increasing the area available for efflux of fluid. It also enables end-to-end nuclear sculpting, removal of the nuclear fragment from the bag, intraocular lens (IOL) implantation, and vitrectomy without stretching the capsular bag. The smaller axis of the oval capsulorhexis facilitates optic capture of a sulcus-fixated IOL. The oval capsulorhexis can be used safely for phacoemulsification of all grades of nuclear sclerosis in posterior polar cataract with preexisting posterior capsule rupture. PMID:21700098

  6. Characterization of Posterior Glenoid Bone Loss

    PubMed Central

    Yanke, Adam Blair; Frank, Rachel M.; Shin, Jason J.; Van Thiel, Geoffrey S.; Verma, Nikhil N.; Cole, Brian J.; Romeo, Anthony A.; Provencher, Matthew T.

    2016-01-01

    Objectives: The purpose of this study was to characterize the morphology and location of posterior glenoid bone loss in pat ients with posterior instability instability utilizing computed tomography (CT). Methods: Clinical data was selected for patients with posterior shoulder instability that had undergone posterior stabilization (open or arthroscopic) or posterior osseous augmentation (distal tibia or iliac crest). Three fellowship-trained surgeons from two institutions contributed patients. Pre-operative CT data was collected for all patients. The axial cuts were segmented and reformatted in three-dimensions for glenoid analysis using Osirix. From this three-dimensional model, the following was calculated: percent bone loss (Nobuhara), total arc of the defect (degrees), and a clock-face description (start point, stop point, and average or direction). Pearson correlation coefficients were performed using significance of p<0.05. Results: Fifty shoulders from 50 patients were reviewed. Fourteen patients (average age 30 years; 93% male) had evidence of posterior glenoid bone loss and were included for evaluation. Defects on average involved 13.7±8.6% of the glenoid (range, 2-35%). The average start time (assuming all right shoulders) on the clock face was 10 o’clock ± 40 minutes and stopped at 6:30 ± 25 minutes. The average direction of the defect pointed toward 8:15 ± 25 minutes. The percent bone loss correlated with the total arc of the defect (Pearson: 0.93, p<0.05, R2: 0.86) and the direction of the bone loss (Pearson: 0.64, p<0.05, R2: 0.40). The direction of bone loss significantly moved more posterosuperior the larger the defect became (Pearson: 0.63, p<0.05, R2: 0.40). Conclusion: Posterior bone loss associated with posterior glenohumeral instability is typically directed posteriorly at 8:15 on the clock. As defect get bigger, this direction moves more posterosuperior. This information will help guide clinicians in understanding the typical location of

  7. The posterior chamber phakic refractive lens (PRL): a review

    PubMed Central

    Pérez-Cambrodí, R J; Piñero, D P; Ferrer-Blasco, T; Cerviño, A; Brautaset, R

    2013-01-01

    Implantation of phakic intraocular lenses (pIOLs) is a reversible refractive procedure, preserving the patient's accommodative function with minimal induction of higher order aberrations compared with corneal photoablative procedures. Despite this, as an intraocular procedure, it has potential risks such as cataracts, chronic uveitis, pupil ovalization, corneal endothelial cell loss, pigmentary dispersion syndrome, pupillary block glaucoma, astigmatism, or endophthalmitis. Currently, only two models of posterior chamber pIOLs are commercially available, the implantable collammer lens (STAAR Surgical Co.) and the phakic refractive lens (PRL; Zeiss Meditec). The number of published reports on the latter is very low, and some concerns still remain about its long-term safety. The present article reviews the published literature on the outcomes after PRL implantation in order to provide a general overview and evaluate its real potential as a surgical refractive option. PMID:23222559

  8. Regression of chronic posterior leukoencephalopathy after stop of methotrexate treatment.

    PubMed

    Marcon, Gabriella; Giovagnoli, Anna Rita; Mangiapane, Paola; Erbetta, Alessandra; Tagliavini, Fabrizio; Girotti, Floriano

    2009-10-01

    Posterior reversible leukoencephalopathy (PRLE) is a neurological disorder caused by a variety of pathological conditions such as high doses or long-term low-doses of immunosuppressive therapy. PRLE associated with methotrexate (MTX) is well known but it was rarely observed in adult patients submitted to long-term low-dose administration via the oral route. Here we report the case of a patient affected by psoriasis, treated by chronic oral low-dose of MTX, who presented with limb ideomotor apraxia. Magnetic resonance (MRI) of the brain showed, on T2-weighted images, a diffuse hyperintensity involving bilaterally the white matter of the occipital, parietal and frontal lobes. MTX treatment was stopped and, at the 6-month follow-up, the neuropsychological performances was improved. Two years later, the neuropsychological profile was normal and MRI showed a regression of the white matter abnormalities. PMID:19626273

  9. The posterior chamber phakic refractive lens (PRL): a review.

    PubMed

    Pérez-Cambrodí, R J; Piñero, D P; Ferrer-Blasco, T; Cerviño, A; Brautaset, R

    2013-01-01

    Implantation of phakic intraocular lenses (pIOLs) is a reversible refractive procedure, preserving the patient's accommodative function with minimal induction of higher order aberrations compared with corneal photoablative procedures. Despite this, as an intraocular procedure, it has potential risks such as cataracts, chronic uveitis, pupil ovalization, corneal endothelial cell loss, pigmentary dispersion syndrome, pupillary block glaucoma, astigmatism, or endophthalmitis. Currently, only two models of posterior chamber pIOLs are commercially available, the implantable collammer lens (STAAR Surgical Co.) and the phakic refractive lens (PRL; Zeiss Meditec). The number of published reports on the latter is very low, and some concerns still remain about its long-term safety. The present article reviews the published literature on the outcomes after PRL implantation in order to provide a general overview and evaluate its real potential as a surgical refractive option. PMID:23222559

  10. Posterior Predictive Bayesian Phylogenetic Model Selection

    PubMed Central

    Lewis, Paul O.; Xie, Wangang; Chen, Ming-Hui; Fan, Yu; Kuo, Lynn

    2014-01-01

    We present two distinctly different posterior predictive approaches to Bayesian phylogenetic model selection and illustrate these methods using examples from green algal protein-coding cpDNA sequences and flowering plant rDNA sequences. The Gelfand–Ghosh (GG) approach allows dissection of an overall measure of model fit into components due to posterior predictive variance (GGp) and goodness-of-fit (GGg), which distinguishes this method from the posterior predictive P-value approach. The conditional predictive ordinate (CPO) method provides a site-specific measure of model fit useful for exploratory analyses and can be combined over sites yielding the log pseudomarginal likelihood (LPML) which is useful as an overall measure of model fit. CPO provides a useful cross-validation approach that is computationally efficient, requiring only a sample from the posterior distribution (no additional simulation is required). Both GG and CPO add new perspectives to Bayesian phylogenetic model selection based on the predictive abilities of models and complement the perspective provided by the marginal likelihood (including Bayes Factor comparisons) based solely on the fit of competing models to observed data. [Bayesian; conditional predictive ordinate; CPO; L-measure; LPML; model selection; phylogenetics; posterior predictive.] PMID:24193892

  11. Posterior osseous bridging of C1.

    PubMed

    Simsek, Serkan; Yigitkanli, Kazim; Comert, Ayhan; Acar, Halil I; Seckin, Hakan; Er, Uygur; Belen, Deniz; Tekdemir, Ibrahim; Elhan, Alaittin

    2008-06-01

    The sulcus of the vertebral artery is located behind the lateral mass of the atlas and in some cases is converted into a foramen by anomalous ossification known as the posterior ponticulus (osseous bridge). This study involved anatomical observations of 158 isolated anatomical specimens of dry C1 vertebrae. The incidence and types of posterior osseous bridging were identified for the 158 dry samples of atlas vertebrae. In nine (5.6%) dry C1 vertebrae, partial osseous bridging was detected (bilaterally in eight vertebrae and unilaterally on the left in one). Complete osseous bridging (arcuate foramen) was observed in six (3.8%) dry C1 vertebrae (bilaterally in one vertebra, unilaterally on the left in three, and on the right in two). Awareness of the types of posterior osseous bridging of C1 in craniocervical junction surgery is essential, and may be helpful in surgical interventions in this region. PMID:18378457

  12. Posterior predictive checking of multiple imputation models.

    PubMed

    Nguyen, Cattram D; Lee, Katherine J; Carlin, John B

    2015-07-01

    Multiple imputation is gaining popularity as a strategy for handling missing data, but there is a scarcity of tools for checking imputation models, a critical step in model fitting. Posterior predictive checking (PPC) has been recommended as an imputation diagnostic. PPC involves simulating "replicated" data from the posterior predictive distribution of the model under scrutiny. Model fit is assessed by examining whether the analysis from the observed data appears typical of results obtained from the replicates produced by the model. A proposed diagnostic measure is the posterior predictive "p-value", an extreme value of which (i.e., a value close to 0 or 1) suggests a misfit between the model and the data. The aim of this study was to evaluate the performance of the posterior predictive p-value as an imputation diagnostic. Using simulation methods, we deliberately misspecified imputation models to determine whether posterior predictive p-values were effective in identifying these problems. When estimating the regression parameter of interest, we found that more extreme p-values were associated with poorer imputation model performance, although the results highlighted that traditional thresholds for classical p-values do not apply in this context. A shortcoming of the PPC method was its reduced ability to detect misspecified models with increasing amounts of missing data. Despite the limitations of posterior predictive p-values, they appear to have a valuable place in the imputer's toolkit. In addition to automated checking using p-values, we recommend imputers perform graphical checks and examine other summaries of the test quantity distribution. PMID:25939490

  13. Detección y estudio mediante Fluorescencia Inducida por Láser de radicales libres formados por Disociación Multifotónica Infrarroja

    NASA Astrophysics Data System (ADS)

    Santos, M.; Díaz, L.; Torresano, J. A.; Rubio, L.; Samoudi, B.

    Una de las principales aplicaciones actuales de los procesos de disociación multifotónica inducidos por radiación láser infrarroja (DMI) es la producción de radiales libres, con el fin de estudiar sus propiedades cinéticas y espectroscópicas. La disociación de moléculas poliatómicas en el IR con láseres de CO2 tiene lugar desde la superficie de energía molecular mas baja y conduce generalmente a la formación de fragmentos en el estado electrónico fundamental, con diversos grados de excitación vibracional. En el Grupo de Procesos Multifotónicos del Instituto de Estructura de la Materia del C.S.I.C. hemos puesto a punto la técnica de Fluorescencia Inducida por Láser (LIF) para la detección y análisis en tiempo real de los fragmentos producidos en la DMI inducida mediante uno o dos campos láseres de diferentes longitudes de onda. Objetivos de nuestro trabajo han sido el estudio de los canales de disociación mayoritarios y de las especies transitoria producidas, así como de la distribución de energía interna con que éstas son generadas. En particular hemos detectado mediante LIF las especies: C2, CF, CH, SiH2, CF2, CH2, SiHCl, y CF3 a partir de la disociación de, entre otras, las siguientes moléculas: C2H3Br, C3F6, C4H8Si, C2H5ClSi y CH5ClSi. En este trabajo presentamos algunos de los resultados obtenidos mediante el estudio por LIF de estos radicales: estudio temporal de la señal LIF obtenida con determinación de tiempos de vida, espectros de excitación y fluorescencia, temperaturas vibracionales de formación, variación de la intensidad LIF con el tiempo de retraso entre los láseres de disociación y prueba, etc.

  14. Imaging the posterior mediastinum: a multimodality approach

    PubMed Central

    Occhipinti, Mariaelena; Heidinger, Benedikt H.; Franquet, Elisa; Eisenberg, Ronald L.; Bankier, Alexander A.

    2015-01-01

    The posterior mediastinum contains several structures that can produce a wide variety of pathologic conditions. Descending thoracic aorta, esophagus, azygos and hemiazygos veins, thoracic duct, lymph nodes, adipose tissue, and nerves are all located in this anatomical region and can produce diverse abnormalities. Although chest radiography may detect many of these pathologic conditions, computed tomography and magnetic resonance are the imaging modalities of choice for further defining the relationship of posterior mediastinal lesions to neighboring structures and showing specific imaging features that narrow the differential diagnosis. This review emphasizes modality-related answers to morphologic questions, which provide precise diagnostic information. PMID:25993732

  15. Imaging the posterior mediastinum: a multimodality approach.

    PubMed

    Occhipinti, Mariaelena; Heidinger, Benedikt H; Franquet, Elisa; Eisenberg, Ronald L; Bankier, Alexander A

    2015-01-01

    The posterior mediastinum contains several structures that can produce a wide variety of pathologic conditions. Descending thoracic aorta, esophagus, azygos and hemiazygos veins, thoracic duct, lymph nodes, adipose tissue, and nerves are all located in this anatomical region and can produce diverse abnormalities. Although chest radiography may detect many of these pathologic conditions, computed tomography and magnetic resonance are the imaging modalities of choice for further defining the relationship of posterior mediastinal lesions to neighboring structures and showing specific imaging features that narrow the differential diagnosis. This review emphasizes modality-related answers to morphologic questions, which provide precise diagnostic information. PMID:25993732

  16. Arthroscopic Approach to Posterior Ankle Impingement.

    PubMed

    Theodoulou, Michael H; Bohman, Laura

    2016-10-01

    Posterior ankle pain can occur for many reasons. If it is produced by forced plantarflexion of the foot, it is often a result of impingement from an enlarged posterior talar process or an os trigonum. This condition may present in an acute or chronic state. Management is initially nonoperative, but surgical treatments are available. This condition is often seen in athletes, so procedures that limit surgical trauma and allow early return to activity are ideal. An arthroscopic approach for this disorder produces good outcomes with limited complications. Understanding the indications, local anatomy, and surgical technique, allows good, reproducible outcomes. PMID:27599438

  17. [Therapy of posterior and posterolateral knee instability].

    PubMed

    Jakob, R P; Rüegsegger, M

    1993-11-01

    The natural course after posterior cruciate ligament (PCL) tear is a slow process of degeneration starting in the medial compartment. Functional disability is mainly present in those instabilities that are combined with posterolateral insufficiency. The surgical treatment at present mainly addresses these combined types of posterior-posterolateral instability. It is generally agreed that suture of the torn PCL alone is insufficient and augmentation with autologous structures, such as the patellar ligament, are mandatory. Synthetic augmentation to facilitate after treatment is another adjunct. Because of the difficulty of precise tibial tunnel placement a two-stage procedure is advocated, an anterior approach with the patient supine being used for femoral graft placement. If a posterior approach with the patient prone is used, a straight posterior incision is made between the two heads of the gastrocnemius and the neuromuscular bundle. With this approach the tibial bone block is placed in a trough. The accuracy of graft placement and the immediate functional aftertreatment facilitated by the use of osseous fixation of a synthetic augmentation device at both ends have made better results of surgical reconstruction of the PCL possible. PMID:8309701

  18. Posterior instability caused by batter's shoulder.

    PubMed

    Kang, Richard W; Mahony, Gregory T; Harris, Thomas C; Dines, Joshua S

    2013-10-01

    In summary, batter’s shoulder is a rare and only recently recognized entity. This condition is posterior shoulder instability caused by a missed attempt at hitting a pitch, especially with an outside pitch. The lack of counterforce from hitting a ball produces increased forces imparted on the posterior capsulolabral complex of the lead shoulder during batting. If the player fails conservative management, she or he can undergo an arthroscopic posterior labral repair instead of debridement. After treatment, the player can expect to return to play after approximately 6 to 7 months. Initial results from a small, retrospective series demonstrate greater than 90% excellent results. These findings are similar to current literature for arthroscopic treatment of posterior instability, which reports success rates that range from 75% to 91%. Longer-term follow-up will be needed to determine the natural history and prognosis or batter’s shoulder. Based on initial results, the authors predict good to excellent results for most players with batter’s shoulder who undergo proper treatment. Additionally, with the exception of switch hitters, the nonthrowing arm is affected. This can also improve the athlete’s return to play. PMID:24079435

  19. Posterior Probabilities for a Consensus Ordering.

    ERIC Educational Resources Information Center

    Fligner, Michael A.; Verducci, Joseph S.

    1990-01-01

    The concept of consensus ordering is defined, and formulas for exact and approximate posterior probabilities for consensus ordering are developed under the assumption of a generalized Mallows' model with a diffuse conjugate prior. These methods are applied to a data set concerning 98 college students. (SLD)

  20. An Unusual Cause of Posterior Elbow Impingement: Detachment of a Hypertrophied Posterior Fat Pad.

    PubMed

    Hamada, Daisuke; Matsuura, Tetsuya; Sugiura, Kosuke; Higuchi, Tadahiro; Suzue, Naoto; Goto, Tomohiro; Tsutsui, Takahiko; Wada, Keizo; Fukuta, Shoji; Sairyo, Koichi

    2015-01-01

    We report a case of a 47-year-old woman who developed posterior impingement of the elbow due to detachment of a hypertrophied posterior fat pad. She reported acute left elbow pain after leaning back onto a hard object with her hand and subsequently experienced a "catching" sensation. Comparison with the magnetic resonance images of a normal elbow revealed a hypertrophied posterior fat pad interposed between the olecranon and olecranon fossa in both elbows, with the fat pad in the left elbow located more inferiorly than that in the right elbow. Elbow arthroscopy showed the olecranon fossa covered by the fat pad, a portion of which was detached from the rest of the pad. Debridement of the detached portion was performed until no impingement was evident. Postoperatively, full extension of the elbow did not elicit pain. Clinicians should include this pathology among the differential diagnoses for posterior elbow pain. PMID:26613057

  1. Posterior cruciate-retaining versus posterior-stabilized total knee arthroplasty: a meta-analysis.

    PubMed

    Bercik, Michael J; Joshi, Ashish; Parvizi, Javad

    2013-03-01

    The objective of this meta-analysis was to compare outcomes of posterior cruciate-retaining and posterior stabilized prostheses. A computerized literature search was conducted to identify randomized controlled trials comparing the clinical outcomes of cruciate-retaining and posterior-stabilized designs. The table of contents of four major Orthopaedic journals and the references section of two arthroplasty text books were reviewed to identify other relevant studies. Ultimately, 1114 patients (1265 knees) were compared. Statistical analysis revealed a significant difference in flexion and range of motion in favor of posterior-stabilized knees, but no difference in complication rates. The clinical importance of this remains unknown. The decision to use one design versus the other should rest with the surgeon's preference and comfort with a particular design. PMID:23433255

  2. An Unusual Cause of Posterior Elbow Impingement: Detachment of a Hypertrophied Posterior Fat Pad

    PubMed Central

    Hamada, Daisuke; Matsuura, Tetsuya; Sugiura, Kosuke; Higuchi, Tadahiro; Suzue, Naoto; Goto, Tomohiro; Tsutsui, Takahiko; Wada, Keizo; Fukuta, Shoji; Sairyo, Koichi

    2015-01-01

    We report a case of a 47-year-old woman who developed posterior impingement of the elbow due to detachment of a hypertrophied posterior fat pad. She reported acute left elbow pain after leaning back onto a hard object with her hand and subsequently experienced a “catching” sensation. Comparison with the magnetic resonance images of a normal elbow revealed a hypertrophied posterior fat pad interposed between the olecranon and olecranon fossa in both elbows, with the fat pad in the left elbow located more inferiorly than that in the right elbow. Elbow arthroscopy showed the olecranon fossa covered by the fat pad, a portion of which was detached from the rest of the pad. Debridement of the detached portion was performed until no impingement was evident. Postoperatively, full extension of the elbow did not elicit pain. Clinicians should include this pathology among the differential diagnoses for posterior elbow pain. PMID:26613057

  3. Kinematic Analysis of a Posterior-stabilized Knee Prosthesis

    PubMed Central

    Zhao, Zhi-Xin; Wen, Liang; Qu, Tie-Bing; Hou, Li-Li; Xiang, Dong; Bin, Jia

    2015-01-01

    Background: The goal of total knee arthroplasty (TKA) is to restore knee kinematics. Knee prosthesis design plays a very important role in successful restoration. Here, kinematics models of normal and prosthetic knees were created and validated using previously published data. Methods: Computed tomography and magnetic resonance imaging scans of a healthy, anticorrosive female cadaver were used to establish a model of the entire lower limbs, including the femur, tibia, patella, fibula, distal femur cartilage, and medial and lateral menisci, as well as the anterior cruciate, posterior cruciate, medial collateral, and lateral collateral ligaments. The data from the three-dimensional models of the normal knee joint and a posterior-stabilized (PS) knee prosthesis were imported into finite element analysis software to create the final kinematic model of the TKA prosthesis, which was then validated by comparison with a previous study. The displacement of the medial/lateral femur and the internal rotation angle of the tibia were analyzed during 0–135° flexion. Results: Both the output data trends and the measured values derived from the normal knee's kinematics model were very close to the results reported in a previous in vivo study, suggesting that this model can be used for further analyses. The PS knee prosthesis underwent an abnormal forward displacement compared with the normal knee and has insufficient, or insufficiently aggressive, “rollback” compared with the lateral femur of the normal knee. In addition, a certain degree of reverse rotation occurs during flexion of the PS knee prosthesis. Conclusions: There were still several differences between the kinematics of the PS knee prosthesis and a normal knee, suggesting room for improving the design of the PS knee prosthesis. The abnormal kinematics during early flexion shows that the design of the articular surface played a vital role in improving the kinematics of the PS knee prosthesis. PMID:25591565

  4. A Cadaveric Study of Bilateral Configuration of Posterior Bifurcation of Posterior Communicating Artery in Indian Population

    PubMed Central

    Saha, Anubha; Mandal, Shyamash

    2015-01-01

    Introduction: Various studies have been done regarding variations of circle of Willis, but few literatures are available about the detail configurations on Indian population. Posterior communicating artery is the main collateral channel between the vertebrobasilar and carotid system. It may act as a main source of blood flow via posterior cerebral artery if fetal configuration is present. Aim of the study is to see the bilateral configurations to compare the blood supply of both cerebral hemispheres via posterior cerebral artery in human cadavers. Materials and Methods: Fifty six formalin fixed brains were used for study. The specimens were classified into 3 types and 21 subtypes according to the configuration of the vessel of both hemispheres. As hemodynamic balance is dependent on the calibre of the vessel, the diameter of the arteries were also taken into consideration. Pearson’s correlation had been done. Result: In present study type I is 57.2%, type II is 37.5% and type III is 5.4%. Incidence of unilateral fetal type posterior cerebral artery is in high percentage (33.9%). Greatest diameter of posterior communicating artery is 3.8mm on right and 3.6mm on left side. Significant correlations also have been found between arterial segments of different types. Conclusion: It is expected that the study will help to enrich the knowledge about the arterial predominance of origin of posterior cerebral artery of both cerebral hemispheres in normal or variant cases and its effect on perfusion images. PMID:25954608

  5. Posterior Wnts Have Distinct Roles in Specification and Patterning of the Planarian Posterior Region

    PubMed Central

    Sureda-Gómez, Miquel; Pascual-Carreras, Eudald; Adell, Teresa

    2015-01-01

    The wnt signaling pathway is an intercellular communication mechanism essential in cell-fate specification, tissue patterning and regional-identity specification. A βcatenin-dependent signal specifies the AP (Anteroposterior) axis of planarians, both during regeneration of new tissues and during normal homeostasis. Accordingly, four wnts (posterior wnts) are expressed in a nested manner in central and posterior regions of planarians. We have analyzed the specific role of each posterior wnt and the possible cooperation between them in specifying and patterning planarian central and posterior regions. We show that each posterior wnt exerts a distinct role during re-specification and maintenance of the central and posterior planarian regions, and that the integration of the different wnt signals (βcatenin dependent and independent) underlies the patterning of the AP axis from the central region to the tip of the tail. Based on these findings and data from the literature, we propose a model for patterning the planarian AP axis. PMID:26556349

  6. Arthroscopic approach to the posterior compartment of the knee using a posterior transseptal portal

    PubMed Central

    Ohishi, Tsuyoshi; Takahashi, Masaaki; Suzuki, Daisuke; Matsuyama, Yukihiro

    2015-01-01

    Arthroscopic surgery of the posterior compartment of the knee is difficult when only two anterior portals are used for access because of the inaccessibility of the back of the knee. Since its introduction, the posterior transseptal portal has been widely employed to access lesions in the posterior compartment. However, special care should be taken to avoid neurovascular injuries around the posteromedial, posterolateral, and transseptal portals. Most importantly, popliteal vessel injury should be avoided when creating and using the transseptal portal during surgery. Purpose of the present study is to describe how to avoid the neurovascular injuries during establishing the posterior three portals and to introduce our safer technique to create the transseptal portal. To date, we have performed arthroscopic surgeries via the transseptal portal in the posterior compartments of 161 knees and have not encountered nerve or vascular injury. In our procedure, the posterior septum is perforated with a 1.5-3.0-mm Kirschner wire that is protected by a sheath inserted from the posterolateral portal and monitored from the posteromedial portal to avoid popliteal vessel injury. PMID:26301179

  7. Posterior Wnts Have Distinct Roles in Specification and Patterning of the Planarian Posterior Region.

    PubMed

    Sureda-Gómez, Miquel; Pascual-Carreras, Eudald; Adell, Teresa

    2015-01-01

    The wnt signaling pathway is an intercellular communication mechanism essential in cell-fate specification, tissue patterning and regional-identity specification. A βcatenin-dependent signal specifies the AP (Anteroposterior) axis of planarians, both during regeneration of new tissues and during normal homeostasis. Accordingly, four wnts (posterior wnts) are expressed in a nested manner in central and posterior regions of planarians. We have analyzed the specific role of each posterior wnt and the possible cooperation between them in specifying and patterning planarian central and posterior regions. We show that each posterior wnt exerts a distinct role during re-specification and maintenance of the central and posterior planarian regions, and that the integration of the different wnt signals (βcatenin dependent and independent) underlies the patterning of the AP axis from the central region to the tip of the tail. Based on these findings and data from the literature, we propose a model for patterning the planarian AP axis. PMID:26556349

  8. [Posterior iris bowing after accommodation--elucidation of the etiology of pigment dispersion syndrome].

    PubMed

    Ueda, J; Sawaguchi, S; Watanabe, J; Shirakashi, M; Abe, H

    1997-02-01

    Recent advancements in imaging the anterior segment structures using the ultrasound biomicro scope (UBM) have proven the involvement of posterior iris bowing due to reverse pupillary block as the cause of pigment dispersion syndrome. In this report, we examined whether the posterior iris bowing occurs even in normal eyes following accommodation, and whether the degree of iris concavity tends to be greater in myopic eyes than in emmetropic eyes. The subjects were normal eyes with sufficient accommodation power, i.e. 5 myopic eyes with less than-5 diopter reflection, 5 emmetropic eyes within +/- 1 dioptor reflection, respectively. We obtained UBM images of the iris at 4 portions before and after accommodation, and measured the degree of posterior iris bowing. We found that almost all data shift posteriorly after accommodation, and that the iris concavity is more distinct in myopic eyes than in emmetropic eyes both before and after accommodation (before: p = 0.0004, after: p < 0.0001). From these results, we confirmed that iris concavity after accommodation occurs in normal eyes but not enough for iridozonular contact, and that pigment dispersion syndrome results from augmented iris concavity owing to pre-existing factors such as iris flexibility, myopia, and sufficient accommodation power. PMID:9124102

  9. Posterior fossa lesions associated with neuropsychiatric symptomatology.

    PubMed

    Pollak, L; Klein, C; Rabey, J M; Schiffer, J

    1996-11-01

    We reviewed 7 cases with posterior fossa structural abnormalities (3 tumors, 2 megacisterna magna and 2 Dandy-Walker syndrome) presenting with neuropsychiatric symptomatology. Derangement in the balance of dopamine, serotonin and noradrenergic networks has been implicated in the pathogenesis of schizophrenia, affective and even personality disorders. Disruption of the cerebellar output to mesial dopaminergic areas, locus coeruleus and raphe nuclei, or deafferentation of the thalamolimbic circuits by a cerebellar lesion may lead to behavioral changes. Seven patients (pts) (comprising 4 men and 3 women with mean age 22 years) were diagnosed as suffering from psychosis (2 pts), major depression (1 pt), personality disorders (2 pts) and somatoform disorders (2 pts) (DSM-IV criteria). Brain CT scan (7 pts) and MRI (4 pts) revealed tumors of the posterior fossa (2 pts), megacisterna magna (2 pts) and Dandy-Walker variant (2 pts). In one patient a IVth ventricle tumor was removed in childhood. PMID:9003973

  10. Fractures of posterior teeth in adults.

    PubMed

    Eakle, W S; Maxwell, E H; Braly, B V

    1986-02-01

    Examined in this study were 191 patients with 206 complete or incomplete fractures of posterior teeth. The patients ranged in age from 14 to 76 years, with 66.5% younger than 40 years. The number of fractures occurring in each arch was almost equal. The mandibular first molar was the most frequently fractured posterior tooth. The lingual cusps of mandibular molars fractured more often than did the buccal cusps of mandibular molars by a ratio of 2 to 1. In maxillary molars, buccal and lingual cusps fractured with almost equal frequency, but, in maxillary premolars, the lingual cusps fractured slightly more often than buccal cusps. Data gathered on the widths of the isthmuses of restorations in 109 teeth showed that fewer fractures occurred in teeth with more conservative restorations, with widths of isthmuses a quarter of the inter-cusp distance, and intact marginal ridges. PMID:3456380

  11. The mechanism of continence after posterior urethroplasty

    PubMed Central

    Bagga, Herman S.; Angermeier, Kenneth W.

    2015-01-01

    The standard of care after a pelvic fracture urethral injury is a repair via a one-stage anastomotic posterior urethroplasty using a step-wise perineal approach. The initial injury, immediate postoperative management, and surgical repair can all affect urinary continence in these patients. Proximal continence mechanisms, particularly the bladder neck, are particularly important in maintaining urinary continence in these patients. Patients with bladder neck dysfunction should be counselled about the greater risk of urinary incontinence. PMID:26019981

  12. Cervical disc hernia operations through posterior laminoforaminotomy

    PubMed Central

    Yolas, Coskun; Ozdemir, Nuriye Guzin; Okay, Hilmi Onder; Kanat, Ayhan; Senol, Mehmet; Atci, Ibrahim Burak; Yilmaz, Hakan; Coban, Mustafa Kemal; Yuksel, Mehmet Onur; Kahraman, Umit

    2016-01-01

    Objective: The most common used technique for posterolateral cervical disc herniations is anterior approach. However, posterior cervical laminotoforaminomy can provide excellent results in appropriately selected patients with foraminal stenosis in either soft disc prolapse or cervical spondylosis. The purpose of this study was to present the clinical outcomes following posterior laminoforaminotomy in patients with radiculopathy. Materials and Methods: We retrospectively evaluated 35 patients diagnosed with posterolateral cervical disc herniation and cervical spondylosis with foraminal stenosis causing radiculopathy operated by the posterior cervical keyhole laminoforaminotomy between the years 2010 and 2015. Results: The file records and the radiographic images of the 35 patients were assessed retrospectively. The mean age was 46.4 years (range: 34-66 years). Of the patients, 19 were males and 16 were females. In all of the patients, the neurologic deficit observed was radiculopathy. The posterolaterally localized disc herniations and the osteophytic structures were on the left side in 18 cases and on the right in 17 cases. In 10 of the patients, the disc level was at C5-6, in 18 at C6-7, in 2 at C3-4, in 2 at C4-5, in 1 at C7-T1, in 1 patient at both C5-6 and C6-7, and in 1 at both C4-5 and C5-6. In 14 of these 35 patients, both osteophytic structures and protruded disc herniation were present. Intervertebral foramen stenosis was present in all of the patients with osteophytes. Postoperatively, in 31 patients the complaints were relieved completely and four patients had complaints of neck pain and paresthesia radiating to the arm (the success of operation was 88.5%). On control examinations, there was no finding of instability or cervical kyphosis. Conclusion: Posterior cervical laminoforaminotomy is an alternative appropriate choice in both cervical soft disc herniations and cervical stenosis. PMID:27217655

  13. The diagnostic dilemma of the posterior mediastinal thymus: CT manifestations

    SciTech Connect

    Cohen, M.D.; Weber, T.R.; Sequeira, F.W.; Vane, D.W.; King, H.

    1983-03-01

    Extension of the normal thymus into the posterior mediastinum is rare. The CT appearance of this anomaly in an infant is presented. A mass of soft-tissue density extended from the anterior mediastinum to the posterior chest wall. The absence of any tissue-cleavage plane in the lesion and a smooth continuous lateral margin are signs of posterior extension of the thymus, and they help to distinguish this from a normal anterior thymus being present with a posterior tumor.

  14. Indocyanine green angiography in posterior uveitis

    PubMed Central

    Agrawal, Rupesh V; Biswas, Jyotirmay; Gunasekaran, Dinesh

    2013-01-01

    Literature review for indocyanine green angiography and evaluate the role of indocyanine green angiogram (ICGA) in patients with posterior uveitis seen at a tertiary referral eye care centre. Detailed review of the literature on ICGA was performed. Retrospective review of medical records of patients with posterior uveitis and dual fundus and ICGA was done after institutional board approval. Eighteen patients (26 eyes) had serpiginous choroiditis out of which 12 patients had active choroiditis and six patients had healed choroiditis, six patients (12 eyes) had ampiginous choroiditis, six patients (12 eyes) had acute multifocal posterior placoid pigment epitheliopathy, eight patients (10 eyes) had multifocal choroiditis, four patients (eight eyes) had presumed ocular histoplasmosis syndrome, four patients (eight eyes) had presumed tuberculous choroiditis, two patients (four eyes) had multiple evanescent white dot syndrome and two patients (four eyes) had Vogt Koyanagi Harada (VKH) syndrome. The most characteristic feature noted on ICGA was the presence of different patterns of hypofluorescent dark spots, which were present at different stages of the angiogram. ICGA provides the clinician with a powerful adjunctive tool in choroidal inflammatory disorders. It is not meant to replace already proven modalities such as the fluorescein angiography, but it can provide additional information that is useful in establishing a more definitive diagnosis in inflammatory chorioretinal diseases associated with multiple spots. It still needs to be determined if ICGA can prove to be a follow up parameter to evaluate disease progression. PMID:23685486

  15. Electrocardiographic diagnosis of remote posterior wall myocardial infarction using unipolar posterior lead V9

    SciTech Connect

    Rich, M.W.; Imburgia, M.; King, T.R.; Fischer, K.C.; Kovach, K.L. )

    1989-09-01

    The accuracy of four electrocardiographic criteria for diagnosing remote posterior myocardial infarction was assessed prospectively in 369 patients undergoing exercise treadmill testing with thallium scintigraphy. Criteria included the following: (1) R-wave width greater than or equal to 0.04 s and R-wave greater than or equal to S-wave in V1; (2) R-wave greater than or equal to S-wave in V2; (3) T-wave voltage in V2 minus V6 greater than or equal to 0.38 mV (T-wave index); (4) Q-wave greater than or equal to 0.04 s in left paraspinal lead V9. Twenty-seven patients (7.3 percent) met thallium criteria for posterior myocardial infarction, defined as a persistent perfusion defect in the posterobase of the left ventricle. Sensitivities for the four criteria ranged from 4 to 56 percent, and specificities ranged from 64 to 99 percent. Posterior paraspinal lead V9 provided the best overall predictive accuracy (94 percent), positive predictive value (58 percent), and ability to differentiate patients with and without posterior myocardial infarction of any single criterion (p less than .0001). Combining the T-wave index with lead V9 further enhanced the diagnostic yield: the sensitivity for detecting posterior infarction by at least one of these criteria was 78 percent, and when both criteria were positive, specificity was 98.5 percent. It is concluded that a single, unipolar posterior lead in the V9 position is superior to standard 12-lead electrocardiographic criteria in diagnosing remote posterior myocardial infarction, and that combining V9 with the T-wave index maximizes the diagnostic yield.

  16. Reversible Thermoset Adhesives

    NASA Technical Reports Server (NTRS)

    Mac Murray, Benjamin C. (Inventor); Tong, Tat H. (Inventor); Hreha, Richard D. (Inventor)

    2016-01-01

    Embodiments of a reversible thermoset adhesive formed by incorporating thermally-reversible cross-linking units and a method for making the reversible thermoset adhesive are provided. One approach to formulating reversible thermoset adhesives includes incorporating dienes, such as furans, and dienophiles, such as maleimides, into a polymer network as reversible covalent cross-links using Diels Alder cross-link formation between the diene and dienophile. The chemical components may be selected based on their compatibility with adhesive chemistry as well as their ability to undergo controlled, reversible cross-linking chemistry.

  17. Anterior and posterior fixation for delayed treatment of posterior atlantoaxial dislocation without fracture.

    PubMed

    Yu, Hai Ming; Malhotra, Karan; Butler, Joseph S; Wu, Shi Qiang

    2015-01-01

    Posterior atlantoaxial dislocation (PAAD) without fracture of the odontoid process is a rare injury. Authors have variously reported closed or open reduction, followed by either anterior or posterior fixation, but there is no consensus on best treatment. We present a particularly unstable case of PAAD. Open reduction through a retropharyngeal approach with odontoidectomy was required for reduction. Anterior fixation with transarticular lag screws was required prior to posterior fixation with pedicle screws. Despite non-compliance with postoperative immobilisation, imaging at 20-month follow-up confirmed solid fusion. The patient is pain-free with a good range of movement of the neck and has returned to a manual job. Our case had a greater degree of instability than was previously reported, which necessitated 360° fixation. This is the first reported case of this treatment strategy, which provided a very stable fixation allowing fusion despite early movement and without causing undue stiffness. PMID:26516249

  18. Usefulness of three posterior chest leads for the detection of posterior wall acute myocardial infarction.

    PubMed

    Aqel, Raed A; Hage, Fadi G; Ellipeddi, Pavani; Blackmon, Linda; McElderry, Hugh T; Kay, G Neal; Plumb, Vance; Iskandrian, Ami E

    2009-01-15

    A significant proportion of patients with myocardial infarction are missed upon initial presentation to the emergency department. The 12-lead electrocardiogram (ECG) has a low sensitivity for the detection of acute myocardial infarction, especially if the culprit lesion is in the left circumflex artery (LCA). This study was designed to evaluate the benefit of adding 3 posterior chest leads on top of the 12-lead ECG to detect ischemia resulting from LC disease, using a model of temporary balloon occlusion to produce ischemia. We studied 53 consecutive patients who underwent clinically indicated coronary interventions. At the time of coronary angiography, the balloon was inflated to produce complete occlusion of the proximal LCA. We recorded and analyzed the changes noted on the 15-lead ECG, which included 3 posterior leads in addition to the standard 12 leads. In response to acute occlusion of the LCA, the posterior chest leads showed more ST elevation than the other leads, and more patients had ST elevation in the posterior leads than in any other lead. The 15-lead ECG was able to detect>or=0.5 mm (74% vs 38%, p<0.0001) and >or=1 mm (62% vs 34%, p<0.0001) ST elevation in any 2 contiguous leads more frequently than the 12-lead ECG. In conclusion, the 15-lead ECG identified more patients with posterior myocardial wall ischemia because of temporary balloon occlusion of the LC than the 12-lead ECG. This information may enhance the detection of posterior MI in the emergency department and potentially facilitate early institution of reperfusion therapy. PMID:19121429

  19. Case report of a posterior disc displacement without and with reduction.

    PubMed

    Huddleston Slater, James J R; Lobbezoo, Frank; Hofman, Nico; Naeije, Machiel

    2005-01-01

    This article presents the case of a patient with an acute posterior disc displacement without reduction (PDDWR), whose temporomandibular joint (TMJ) showed, after physiotherapeutic manipulation, the characteristics of a posterior disc displacement with reduction (PDDR). Opto-electronic condylar movement recordings in both the PDDR state and the PDDWR state, and magnetic resonance imaging (MRI) scans of the TMJ in the PDDR state were carried out to document the case. The first 2 physiotherapeutic manipulations were initially successful in reducing the disc, but a few days later the joint showed a relapse to the PDDWR state. From the third manipulation on, now 12 months ago, the patient has been free of symptoms of the PDDWR state. Condylar movement traces of the joint in the PDDWR state indicated that the condyle was prevented from entering the fossa completely. The downward condylar movement deflections during the early phase of closing, recorded after the second manipulation, showed the reduction of the posteriorly displaced disc during closing. The movement recordings also showed that the PDDR could be eliminated by submaximal opening and closing movements. The MRI scans, taken after the third, successful manipulation, showed the disc to be in a normal position with respect to the condyle when the mouth was closed, and to be posteriorly displaced when the mouth was maximally opened. The case shows that manipulation techniques may successfully reverse an acute PDDWR into a PDDR. The technique of MRIs and condylar movement recordings show promise in further unraveling the morphological and clinical features of posterior disc displacements. PMID:16279486

  20. Centrally injected histamine increases posterior hypothalamic acetylcholine release in hemorrhage-hypotensive rats.

    PubMed

    Altinbas, Burcin; Yilmaz, Mustafa S; Savci, Vahide; Jochem, Jerzy; Yalcin, Murat

    2015-01-01

    Histamine, acting centrally as a neurotransmitter, evokes a reversal of hemorrhagic hypotension in rats due to the activation of the sympathetic and the renin-angiotensin systems as well as the release of arginine vasopressin and proopiomelanocortin-derived peptides. We demonstrated previously that central nicotinic cholinergic receptors are involved in the pressor effect of histamine. The aim of the present study was to examine influences of centrally administrated histamine on acetylcholine (ACh) release at the posterior hypothalamus-a region characterized by location of histaminergic and cholinergic neurons involved in the regulation of the sympathetic activity in the cardiovascular system-in hemorrhage-hypotensive anesthetized rats. Hemodynamic and microdialysis studies were carried out in Sprague-Dawley rats. Hemorrhagic hypotension was induced by withdrawal of a volume of 1.5 ml blood/100 g body weight over a period of 10 min. Acute hemorrhage led to a severe and long-lasting decrease in mean arterial pressure (MAP), heart rate (HR), and an increase in extracellular posterior hypothalamic ACh and choline (Ch) levels by 56% and 59%, respectively. Intracerebroventricularly (i.c.v.) administered histamine (50, 100, and 200 nmol) dose- and time-dependently increased MAP and HR and caused an additional rise in extracellular posterior hypothalamic ACh and Ch levels at the most by 102%, as compared to the control saline-treated group. Histamine H1 receptor antagonist chlorpheniramine (50 nmol; i.c.v.) completely blocked histamine-evoked hemodynamic and extracellular posterior hypothalamic ACh and Ch changes, whereas H2 and H3/H4 receptor blockers ranitidine (50 nmol; i.c.v.) and thioperamide (50 nmol; i.c.v.) had no effect. In conclusion, centrally administered histamine, acting via H1 receptors, increases ACh release at the posterior hypothalamus and causes a pressor and tachycardic response in hemorrhage-hypotensive anesthetized rats. PMID:25468497

  1. Surgical options for posterior tibial plateau fracture

    PubMed Central

    Chen, Hongwei; Wu, Lijun

    2015-01-01

    Objective: To investigate surgical methods and clinical effectiveness of posteromedial and posterolateral approaches for the posterior tibial plateau fracture. Method: 21 cases who received surgery through posterior approaches for the treatment of posterior tibial plateau fractures (PTPFs) were included. Results: 21 cases were subject to follow-up for 12-24 months (an average of 16.2 months). No cases developed incision inflammation, neurovascular injury, internal fixation loosening and breakage. All fractures were healed. No cases developed knee varus and valgus deformity and fracture dislocation. After surgery, Rasmussen score for knee joint functions was 13-30 points (a mean of 24.2). The results were excellent in 12 cases, good in 7 cases and fair in 2 cases. The percentage of excellent and good results was 90.5%. Rasmussen radiology score was 10-18 points (a mean of 15.6 points). The results were excellent in 13 cases, good in 7 cases and fair in 1 cases. The percentage of excellent and good results was 95.2%. 1 case had significant limited range of knee flexion and extension, which was improved after phase II release under arthroscopy combined with function exercise. 2 cases developed traumatic arthritis, which was relieved after intra-articular injection with sodium hyaluronate and oral nonsteroidal anti-inflammatory drug. Conclusion: The posteromedial and posterolateral approaches for PTPF is good for reduction and fixation of PTPF. The approaches have benefits such as clear exposure, convenient placement of internal fixation, less trauma and good clinical outcome. PMID:26885086

  2. Complications when augmenting the posterior maxilla.

    PubMed

    Fugazzotto, Paul; Melnick, Philip R; Al-Sabbagh, Mohanad

    2015-01-01

    The maxillary posterior edentulous region presents a challenge when planning for restoring missing teeth with a dental implant. The available bone in such cases is often not dense and not adequate for the placement of a properly sized implant because of maxillary sinus pneumatization and alveolar bone loss. Maxillary sinus lift is a predictable procedure to provide adequate bone height for the purpose of implant placement. However, complications are encountered during or after the execution of the sinus lift procedure. In this article, the prevention and management of maxillary sinus complications are discussed. PMID:25434561

  3. Trigeminal neuralgia secondary to posterior fossa tumor.

    PubMed

    Agrawal, Mamta; Agrawal, Vikrant; Agrawal, Rajiv; Pramod, D S R

    2010-01-01

    Trigeminal neuralgia (TN) is by no means an uncommon entity presenting as typical or atypical pain syndrome with a standard treatment protocol consisting of medical and surgical therapies. The diagnosis of TN is mainly dependent on the characteristics of symptoms conveyed by the patient and the clinical presentation. Careful history taking, proper interpretation of the signs and symptoms and cranial nerve assessment are necessary for proper diagnosis. Here, we report a case of TN, treated for dental problems and then for neuralgia with only short-term relief. Subsequently, the patient underwent neuroimaging and was found to be having an uncommon space-occupying lesion in the posterior cranial fossa. PMID:22442556

  4. Reverse Correlation in Neurophysiology

    ERIC Educational Resources Information Center

    Ringach, Dario; Shapley, Robert

    2004-01-01

    This article presents a review of reverse correlation in neurophysiology. We discuss the basis of reverse correlation in linear transducers and in spiking neurons. The application of reverse correlation to measure the receptive fields of visual neurons using white noise and m-sequences, and classical findings about spatial and color processing in…

  5. Hydatidosis of the liver and posterior mediastinum

    PubMed Central

    Quail, Jacob F; Gramins, Daniel L; Dutton, William D

    2014-01-01

    Introduction Cystic echinococcus (CE) is an endemic zoonosis secondary to infection by the larval form of the cestode Echinococcus granulosus. An intermediate host, humans enter the organism’s life cycle by exposure to infected canid feces. The liver is the most common location of CE while mediastinal hydatid cysts are rarely reported. Presentation of case We report a case of synchronous CE of the liver and posterior mediastinum treated sequentially using chemotherapy, percutaneous aspiration with injection of a scolicidal agent and re-aspiration (PAIR) and then staged minimally-invasive surgeries. Discussion Synchronous CE involving the liver and posterior mediastinum is rare. The treatment of hydatid liver and mediastinal disease is multimodal including chemotherapy, percutaneous and laparoscopic or open surgical interventions. One option for controlled puncture of hepatic and mediastinal CE includes PAIR followed by surgery. Conclusion The sequential use of chemotherapy and PAIR followed by surgery provides another treatment strategy for management of CE. We believe this strategy may be used safely in locations without endemic CE, including most regions of the United States. PMID:25562598

  6. Traumatic posterior dislocation of hip in children.

    PubMed

    Kutty, S; Thornes, B; Curtin, W A; Gilmore, M F

    2001-02-01

    Traumatic posterior dislocation of the hip joint in children is an uncommon injury. It constitutes a true orthopedic emergency. It makes up over 80% of pediatric hip dislocations. In children, it can occur as a result of minimal trauma, which is attributed to a soft pliable acetabulum and ligamentous laxity. In skeletally mature adolescents, a greater force is required to dislocate the hip joint. Delay in reduction is associated with long-term complications such as avascular necrosis and degenerative arthritis. Avascular necrosis is related to the duration of dislocation. A poorer prognosis is associated with delay in reduction beyond 6 hours, advanced skeletal maturity, or multiple traumas. Prompt reduction minimizes complications. We report two cases of traumatic posterior dislocation of hip in children aged 3 and 14 years. Both were reduced within 6 hours of dislocation, and review at 6 months revealed normal examination and no evidence of any post-traumatic changes. Post-reduction treatment remains without a consensus. This review highlights the clinical presentation, management, and time-sensitive complications of the injury. PMID:11265904

  7. The posterior calf fascial free flap.

    PubMed

    Walton, R L; Matory, W E; Petry, J J

    1985-12-01

    Six posterior calf fascial free flaps were employed to reconstruct defects of the upper and lower extremities. One flap failed due to a constricting dressing. Two flaps sustained partial loss secondary to bleeding and hematoma formation. One flap dehisced at the distal suture line due to mobility of an underlying fracture. All surviving flaps eventually healed and resulted in stable, thin coverage. Donor-site morbidity has been minimal. Shortcomings of this flap model have been defined in the peculiarities of its thinness, diffuse vascular oozing, the extent of the vascular territory, and in postoperative monitoring. These problems are analyzed and recommendations for their resolution are presented. Fascia represents a unique tissue which offers an exciting new dimension in the reconstruction of certain defects--particularly those in which thinness is a desirable option. In the posterior calf model, the inclusion of fat represents an alternative modification that allows the surgeon to tailor the design to a variety of problems where fascia alone is too thin and a cutaneous flap is too thick. This concept may find its greatest application in wounds involving the hand or foot. We believe that this and other fascial flap prototypes may offer an ideal solution for reconstruction of major wounds of the extremities. PMID:3906718

  8. Management of an Uncomplicated Posterior Elbow Dislocation

    PubMed Central

    Blackard, Douglas; Sampson, Jo-Ann

    1997-01-01

    Objective: To present a case of an uncomplicated posterior elbow dislocation in a US World Cup athlete and discuss her rehabilitation. Background: Traditional protocol for management of this injury has been splint immobilization for several weeks, but research suggests a shortened duration of immobilization and early active motion. Differential Diagnosis: Elbow dislocation with possible fracture. Treatment: The dislocation was reduced and a compression bandage and sling were applied. The sports medicine staff and athlete determined that rehabilitation would involve limited immobilization with a posterior splint. Also, active range-of- motion exercises were to be incorporated early in the range-of- motion program to decrease pain at the articulation. Uniqueness: The athlete was not immobilized and her aggressive five-phase rehabilitation program progressed according to decrease in inflammation and increase in range of motion and strength. Conclusions: Shortened immobilization and return to World Championship competition 6 weeks postinjury had no longterm adverse effects on the athlete. ImagesFig 1.Fig 2.Fig 3.Fig 4.Fig. 5. PMID:16558436

  9. Prehension Movements in a Patient (AC) with Posterior Parietal Cortex Damage and Posterior Callosal Section

    ERIC Educational Resources Information Center

    Frak, Victor; Paulignan, Yves; Jeannerod, Marc; Michel, Francois; Cohen, Henri

    2006-01-01

    Prehension movements of the right hand were recorded in a right-handed man (AC), with an injury to the left posterior parietal cortex (PPC) and with a section of the left half of the splenium. The kinematic analysis of AC's grasping movements in direct and perturbed conditions was compared to that of five control subjects. A novel effect in…

  10. Quantum Operation Time Reversal

    SciTech Connect

    Crooks, Gavin E.

    2008-03-25

    The dynamics of an open quantum system can be described by a quantum operation: A linear, complete positive map of operators. Here, I exhibit a compact expression for the time reversal of a quantum operation, which is closely analogous to the time reversal of a classical Markov transition matrix. Since open quantum dynamics are stochastic, and not, in general, deterministic, the time reversal is not, in general, an inversion of the dynamics. Rather, the system relaxes toward equilibrium in both the forward and reverse time directions. The probability of a quantum trajectory and the conjugate, time reversed trajectory are related by the heat exchanged with the environment.

  11. Anterior urethral valve associated with posterior urethral valves: report of 2 cases and review of the literature.

    PubMed

    Tran, Christine N; Reichard, Chad A; McMahon, Daniel; Rhee, Audrey

    2014-08-01

    Anterior urethral valve (AUV) associated with posterior urethral valves (PUVs) is an extremely rare congenital urologic anomaly resulting in lower urinary tract obstruction. We present our experience with 2 children with concomitant AUV and PUV as well as a literature review. The clinical presentation of concomitant AUV and PUV is variable. Successful endoscopic management can result in improvement in renal function, reversal of obstructive changes, and improvement or resolution of voiding dysfunction. PMID:24958476

  12. Biomechanical benefits of anterior offsetting of humeral head component in posteriorly unstable total shoulder arthroplasty: A cadaveric study.

    PubMed

    Kim, Hyun-Min Mike; Chacon, Alexander C; Andrews, Seth H; Roush, Evan P; Cho, Edward; Conaway, William K; Kunselman, Allen R; Lewis, Gregory S

    2016-04-01

    Restoration of joint stability during total shoulder arthroplasty can be challenging in the face of severe glenoid retroversion. A novel technique of humeral head component anterior-offsetting has been proposed to address posterior instability. We evaluated the biomechanical benefits of this technique in cadaveric specimens. Total shoulder arthroplasty was performed in 14 cadaveric shoulders from 7 donors. Complementary shoulders were assigned to either 10° or 20° glenoid retroversion, with retroversion created by eccentric reaming. Two humeral head component offset positions were tested in each specimen: The anatomic (posterior) and anterior (reverse). With loads applied to the rotator cuff and deltoid, joint contact pressures and the force and energy required for posterior humeral head translation were measured. The force and energy required to displace the humeral head posteriorly increased significantly with the anterior offset position compared to the anatomic offset position. The joint contact pressures were significantly shifted anteriorly, and the joint contact area significantly increased with the anterior offset position. Anterior offsetting of the humeral head component increased the resistance to posterior humeral head translation, shifted joint contact pressures anteriorly, and increased joint contact area, thus, potentially increasing the joint stability in total shoulder arthroplasty with simulated glenoid retroversion. PMID:26356804

  13. Reversible right-sided heart failure secondary to carcinoid crisis.

    PubMed

    Soto Herrera, Mariana; Restrepo, José A; Díaz, Jesús H; Ramos, Andrés; Felipe Buitrago, Andrés; Gómez Mejía, Mabel

    2013-01-01

    Carcinoid crisis is an infrequent and little-described complication of neuroendocrine tumors that can be life threatening. It may develop during induction of anesthesia, intraoperatively, during tumor manipulation and arterial embolization, or even spontaneously. The massive release of neuroendocrine substances can lead to potentially fatal complications. Somatostatin analogs inhibit the release of these substances and are the mainstay of treatment. The following case report describes a patient with reversible acute right-sided heart failure posterior to hepatic artery embolization. PMID:24804121

  14. Effect of posterior decompression extent on biomechanical parameters of the spinal cord in cervical ossification of the posterior longitudinal ligament.

    PubMed

    Khuyagbaatar, Batbayar; Kim, Kyungsoo; Park, Won Man; Kim, Yoon Hyuk

    2016-06-01

    Ossification of the posterior longitudinal ligament is a common cause of the cervical myelopathy due to compression of the spinal cord. Patients with ossification of the posterior longitudinal ligament usually require the decompression surgery, and there is a need to better understand the optimal surgical extent with which sufficient decompression without excessive posterior shifting can be achieved. However, few quantitative studies have clarified this optimal extent for decompression of cervical ossification of the posterior longitudinal ligament. We used finite element modeling of the cervical spine and spinal cord to investigate the effect of posterior decompression extent for continuous-type cervical ossification of the posterior longitudinal ligament on changes in stress, strain, and posterior shifting that occur with three different surgical methods (laminectomy, laminoplasty, and hemilaminectomy). As posterior decompression extended, stress and strain in the spinal cord decreased and posterior shifting of the cord increased. The location of the decompression extent also influenced shifting. Laminectomy and laminoplasty were very similar in terms of decompression results, and both were superior to hemilaminectomy in all parameters tested. Decompression to the extents of C3-C6 and C3-C7 of laminectomy and laminoplasty could be considered sufficient with respect to decompression itself. Our findings provide fundamental information regarding the treatment of cervical ossification of the posterior longitudinal ligament and can be applied to patient-specific surgical planning. PMID:26951839

  15. Reversing expectations during discourse comprehension

    PubMed Central

    Xiang, Ming; Kuperberg, Gina

    2014-01-01

    In two ERP experiments, we asked whether comprehenders used the concessive connective, even so, to predict upcoming events. Participants read coherent and incoherent scenarios, with and without even so, e.g. “Elizabeth had a history exam on Monday. She took the test and aced/failed it. (Even so), she went home and celebrated wildly.”, as they rated coherence (Experiment 1) or simply answered intermittent comprehension questions (Experiment 2). The semantic function of even so was used to reverse real-world knowledge predictions, leading to an attenuated N400 to coherent versus incoherent target words (“celebrated”). Moreover, its pragmatic communicative function enhanced predictive processing, leading to more N400 attenuation to coherent targets in scenarios with than without even so. This benefit however, did not come for free: the detection of failed event predictions triggered a later posterior positivity and/or an anterior negativity effect, and costs of maintaining alternative likelihood relations manifest as a sustained negativity effect on sentence-final words. PMID:25914891

  16. Evaluation of posterior fossa lesions by computer assisted tomography (CAT).

    PubMed

    Lott, T; El Gammal, T; Volcan, I

    1977-07-01

    Valuable neuroradiologic information can be obtained with routine examination of the posterior fossa by computer assisted tomography (CAT). The diagnosis can be difficult in the posterior fossa due to the relatively small size of the compartment and its proximities to large bony masses and air in the mastoid cells. However, many lesions can be accurately diagnosed when close attention is given to anatomic detail and the frequent use of contrast enhancement. We introduced a new CAT classification of posterior fossa neoplasms. PMID:877637

  17. Posterior Cruciate Ligament: Focus on Conflicting Issues

    PubMed Central

    Lee, Yong Seuk

    2013-01-01

    There is little consensus on how to optimally reconstruct the posterior cruciate ligament (PCL) and the natural history of injured PCL is also unclear. The graft material (autograft vs. allograft), the type of tibial fixation (tibial inlay vs. transtibial tunnel), the femoral tunnel position within the femoral footprint (isometric, central, or eccentric), and the number of bundles in the reconstruction (1 bundle vs. 2 bundles) are among the many decisions that a surgeon must make in a PCL reconstruction. In addition, there is a paucity of information on rehabilitation after reconstruction of the PCL and posterolateral structures. This article focused on the conflicting issues regarding the PCL, and the scientific rationales behind some critical points are discussed. PMID:24340144

  18. The neuropsychiatric profile of posterior cortical atrophy.

    PubMed

    Isella, Valeria; Villa, Giulia; Mapelli, Cristina; Ferri, Francesca; Appollonio, Ildebrando Marco; Ferrarese, Carlo

    2015-06-01

    We analyzed scores obtained at the Neuropsychiatric Inventory (NPI) by 20 patients with posterior cortical atrophy (PCA) and contrasted it with 20 patients having Alzheimer disease (AD). Patients with hallucinations and delusions were not included due to the high probability of a diagnosis of Lewy body disease. Prevalence of behavioral and psychological symptoms (BPSD) was 95% in the PCA group, the most frequent being apathy and anxiety. Cluster analysis on NPI subscales highlighted a behavioral subsyndrome characterized by agitated temper and irritability. Depression, anxiety, and apathy did not cluster with any other BPSD nor with each other. The PCA group showed a significantly higher proportion of anxious patients and worse anxiety score than patients with AD. No correlation was found between NPI data and demographic, clinical, or neuropsychological features nor were there significant differences for the same variables between anxious and nonanxious cases with PCA. In agreement with anecdotal reports, anxiety seems particularly relevant in PCA. PMID:25330926

  19. [Posterior cortical atrophy with progressive visual agnosia].

    PubMed

    Zarranz, J J; Lasa, A; Fernández, M; Lezcano, E; Pérez Bas, M; Varona, L; Ruiz, J; Beristain, X

    1995-03-01

    Interest in progressive focal cerebral syndromes associated with classical degenerative diseases has increased in recent years. Descriptions of posterior cortical atrophy with progressive visual agnosia are relatively rare. We present 5 patients (2 women) ranging in age between 57 and 72 years old. In all cases symptoms began and progressed with no known etiology. All cases were sporadic. The main clinical signs are difficulty in recognizing objects, colors, persons or places; topographical disorientation and visual memory alterations; alexia, simultagnosia, loss of ocular fixing and optic ataxia. Some patients presented other disturbances of praxis or memory and 2 progressed to global dementia. Language function was preserved and behavioral disturbances did not develop. The amplitude of the P100 visual evoked potential was low but latency was normal in 4 patients and prolonged in 1. Brain images showed atrophy and hypoperfusion in the parieto-occipital area. The neuropathology status of these patients is unknown. PMID:7756009

  20. Iodine-125 radiation of posterior uveal melanoma

    SciTech Connect

    Packer, S.

    1987-12-01

    Twenty-eight cases of posterior choroidal melanoma were treated with iodine-125 in gold eye plaques. Eleven cases were located within 3.0 mm of the optic nerve (group A), nine were within 3.0 mm of the fovea (group B), and eight were within 3.0 mm of the optic nerve and fovea (group C). The mean follow-up of group A was 46.3 months; group B, 25.5 months; and group C, 42.7 months. Complications included macular edema, cataract and tumor growth. Visual acuity remained within two lines of that tested preoperatively for 4 of 11 patients in group A, 4 of 9 in group B, and 5 of 8 in group C. These results with iodine-125 suggest it as an appropriate treatment for patients with choroidal melanoma located near optic nerve and/or macula.

  1. Rapid Maxillary Expansion without Posterior Anchorage.

    PubMed

    Oliveira, Adauê; Amaral, Cássia

    2016-01-01

    This work aimed to evaluate an alternative form of maxillary expansion anchored with mini-implants. A patient 12 years, class III in permanent canine teeth, with multiple agenesis of upper posterior teeth was treated with the aid of four mini-implants in the palate and Haas modified type appliance. During the period of expansion, an interincisal diastema was observed as the first clinical sign of disjunction of the sutures. After correction of cross bite, the expansion of the palate was confirmed by upper occlusal radiographs. Thus, the evaluations showed that the technique was effective and that new scientific studies should be conducted to further develop this subject. Keywords: Appliances; Biomechanics; Implants; Malocclusions PMID:27319047

  2. Ectomesenchymal chondromyxoid tumour of the posterior tongue.

    PubMed

    Cardin, Marie-Josée; Fiset, Pierre Olivier; Zeitouni, Anthony G; Caglar, Derin

    2014-01-01

    Ectomesenchymal chondromyxoid tumor (ECMT) is a rare benign neoplasm arising in the tongue. With only 45 cases reported in the literature, there are several unique features defining this lesion. Firstly, almost all patients present with an asymptomatic slow growing mass on the anterior dorsum of the tongue. At the microscopic level, it is recognizable as a well-circumscribed unencapsulated proliferation of uniform round to fusiform cells embedded in a chondromyxoid matrix. Lastly, the immunohistochemistry profile is characterised by positivity for glial fibrillary acidic protein and frequent positivity for S-100 and cytokeratins. We report a case of a mass located on the posterior dorsum of the tongue and meeting the aforementioned morphological and immunohistochemical criteria of ECMT. PMID:24288100

  3. Tibial Tuberosity-Posterior Cruciate Ligament Distance.

    PubMed

    Daynes, Jake; Hinckel, Betina Bremer; Farr, Jack

    2016-08-01

    When trochlear dysplasia is present, it is difficult to measure the tibial tuberosity to trochlear groove (TT-TG) distance. A new measurement to assess tuberosity position was recently described by Seitlinger et al, which avoids the difficulty of identifying the TG as it references the posterior cruciate ligament (PCL). To evaluate the reproducibility of the Seitlinger et al findings, 42 knees in 41 patients with a documented history of recurrent patellar instability and 84 knees in patients with no history of patellar instability or patellofemoral symptoms were evaluated with magnetic resonance imaging. The TT-PCL distance was increased in the instability group (mean, 21.6 mm) compared with the control group (mean, 19.0 mm). The TT-PCL distance is an independent risk factor for patients with recurrent patellar instability. Its role in surgical planning remains to be determined. PMID:26509659

  4. Is Posterior Leaflet Extension and Associated Commissurotomy

    PubMed Central

    Omeroglu, Suat Nail; Kirali, Kaan; Mansuroglu, Denyan; Goksedef, Deniz; Balkanay, Mehmet; Ipek, Gokhan; Isik, Omer; Yakut, Cevat

    2004-01-01

    In this prospective study, the long-term effect of posterior leaflet extension with glutaraldehyde-preserved autologous pericardium and associated mitral valve commissurotomy was investigated in patients with mixed mitral valve disease of rheumatic origin. Mitral commissurotomy and posterior leaflet extension using a pericardial patch were performed in 25 patients from 1 January 1994 through 31 December 1995 for mixed mitral valve disease. Preoperatively, no patient had chordal rupture or papillary muscle dysfunction. Four patients had left atrial thrombosis. The mean age was 35.7 ± 15.4 years. Associated procedures were tricuspid annuloplasty in 4 patients, aortic annuloplasty in 3, aortic and tricuspid annuloplasty in 1, and aortic homograft replacement in 1. There were no early deaths. One patient died 2 years after surgery due to noncardiac causes. Mitral valve area increased from 1.53 ± 0.63 cm2 to 2 ± 0.33 cm2 (P = 0.09), and left atrial diameter decreased from 5.8 ± 1 cm to 4.86 ± 1.27 cm (P = 0.07) after 6.1 ± 0.7 years (range, 5.5 to 7.1 years). Mitral insufficiency was reduced significantly, from grade 2.65 ± 0.9 to grade 1.2 ± 0.9 (P = 0.007). Functional capacity improved in all patients (New York Heart Association functional class, 3 ± 0.58 preoperatively vs 1.44 ± 0.82 postoperatively; P = 0.001). Three patients required reoperation and valve replacement. This type of reconstruction may be a good alternative for patients who are not able to use anticoagulant therapy. Long-term results of this technique are acceptable; however, the risk of reoperation is an important disadvantage in these young patients. PMID:15562843

  5. Bladder neck incompetence at posterior urethroplasty

    PubMed Central

    Koraitim, Mamdouh M.

    2015-01-01

    The finding of an incompetent bladder neck (BN) at the time of posterior urethroplasty will necessarily exacerbate the already difficult situation. In such cases the aim of the treatment is not only to restore urethral continuity by end-to-end urethral anastomosis, but also to restore the function of the BN to maintain urinary continence. Fortunately, the incidence of incompetence of the BN at posterior urethroplasty is uncommon, usually ≈4.5%. It seems that pelvic fracture-related BN injuries, in contrast to urethral injuries which result from a shearing force, are due to direct injury by the sharp edge of the fractured and displaced pubic bone. The risk of injuries to the BN is greater in children, in patients with a fracture involving both superior and inferior pubic rami on the same side, and in those managed initially by primary realignment. An incompetent BN is suspected by finding an open rectangular BN on cystography, and a fixedly open BN on suprapubic cystoscopy. An incompetent BN can be treated either subsequent to or concomitant with the urethral repair, according to whether a perineal or a perineo-abdominal urethroplasty is used, respectively. Several options have been reported to treat pelvic fracture-related BN incompetence, including reconstructing the BN, forming a new sphincter by tubularisation of a rectangular flap of the anterior bladder wall, and mechanical occlusion by an artificial sphincter or collagen injection. Reconstruction of the BN by the Young-Dees-Leadbetter∗∗ procedure probably provides the most successful results. PMID:26019982

  6. Diagnostics for insufficiencies of posterior calculations in Bayesian signal inference.

    PubMed

    Dorn, Sebastian; Oppermann, Niels; Ensslin, Torsten A

    2013-11-01

    We present an error-diagnostic validation method for posterior distributions in Bayesian signal inference, an advancement of a previous work. It transfers deviations from the correct posterior into characteristic deviations from a uniform distribution of a quantity constructed for this purpose. We show that this method is able to reveal and discriminate several kinds of numerical and approximation errors, as well as their impact on the posterior distribution. For this we present four typical analytical examples of posteriors with incorrect variance, skewness, position of the maximum, or normalization. We show further how this test can be applied to multidimensional signals. PMID:24329375

  7. Simultaneous correction of functional posterior cross bite and midline shift

    PubMed Central

    Arvinth, R.; Rana, Shailendra Singh; Duggal, Ritu; Kharbanda, Om Prakash

    2016-01-01

    The most frequent cause of functional posterior crossbite is the reduction in width of the maxillary dental arch. This posterior crossbite is associated with anterior crowding which is presented as an infrapositioned canine or a palatally positioned lateral incisor on one side; this leads to an upper midline shift toward the crowded side. The present case report shows the management of posterior crossbite with functional shift and upper midline shift simultaneously without adverse side effects. In this case, rapid maxillary expansion along with fixed appliance is used to correct posterior crossbite with the upper dental midline shift using reciprocal action of elastic transseptal fibers.

  8. Deep Posterior Compartment Strength and Foot Kinematics in Subjects With Stage II Posterior Tibial Tendon Dysfunction

    PubMed Central

    Neville, Christopher; Flemister, Adolph S.; Houck, Jeff R.

    2010-01-01

    Background Tibialis posterior muscle weakness has been documented in subjects with Stage II posterior tibial tendon dysfunction (PTTD) but the effect of weakness on foot structure remains unclear. The association between strength and flatfoot kinematics may guide treatment such as the use of strengthening programs targeting the tibialis posterior muscle. Materials and Methods Thirty Stage II PTTD subjects (age; 58.1 ± 10.5 years, BMI 30.6 ± 5.4) and 15 matched controls (age; 56.5 ± 7.7 years, BMI 30.6 ± 3.6) volunteered for this study. Deep Posterior Compartment strength was measured from both legs of each subject and the strength ratio was used to compare each subject’s involved side to their uninvolved side. A 20% deficit was defined, a priori, to define two groups of subjects with PTTD. The strength ratio for each group averaged; 1.06 ± 0.1 (range 0.87 to 1.36) for controls, 1.06 ± 0.1 (range, 0.89 to 1.25), for the PTTD strong group, and 0.64 ± 0.2 (range 0.42 to 0.76) for the PTTD weak group. Across four phases of stance, kinematic measures of flatfoot were compared between the three groups using a two-way mixed effect ANOVA model repeated for each kinematic variable. Results Subjects with PTTD regardless of group demonstrated significantly greater hindfoot eversion compared to controls. Subjects with PTTD who were weak demonstrated greater hindfoot eversion compared to subjects with PTTD who were strong. For forefoot abduction and MLA angles the differences between groups depended on the phase of stance with significant differences between each group observed at the pre-swing phase of stance. Conclusion Strength was associated with the degree of flatfoot deformity observed during walking, however, flatfoot deformity may also occur without strength deficits. PMID:20371019

  9. Costello syndrome: Analysis of the posterior cranial fossa in children with posterior fossa crowding

    PubMed Central

    D’Apolito, Gabriella; Panfili, Marco; Zampino, Giuseppe; Tartaglione, Tommaso; Colosimo, Cesare

    2015-01-01

    This study aimed to assess changes in the posterior cranial fossa (PCF) to shed light on the mechanism of cerebellar herniation in children with Costello syndrome (CS) and posterior fossa crowding. We performed a morphovolumetric PCF analysis on brain magnetic resonance imaging (MRI) in seven children with CS (mean age 31 ± 16 months) comparing the MRI scans with those of seven age-matched healthy subjects. PCF volume (PCFV), PCF brain volume (PCFBV) and cerebellar volume (CeV) were assessed on axial T2-weighted MRI. Morphometric parameters (diameters of the foramen magnum, tentorial angle, basiocciput, supraocciput, basisphenoid and exocciput lengths) were measured on sagittal T1-weighted MRI. The volume of the cerebrospinal fluid (CSF) spaces was calculated as PCFV minus PCFBV. Five out of seven CS children showed tonsillar herniation in the upper cervical canal; no child had hydrocephalus but three out of seven children showed ventriculomegaly. In addition, the PCFV/PCFBV ratio, PCFV, CSF spaces volume, basiocciput, basisphenoid and exocciput lengths and latero-lateral and antero-posterior diameters of the foramen magnum were significantly reduced, whereas no significant changes were found in supraocciput length, PCFBV, CeV or hindbrain volume The volumetric reduction of the PCF due to bony posterior fossa hypoplasia is a predisposing factor for developing cerebellar tonsillar herniation through the foramen magnum in children with CS. The altered anatomy of the foramen magnum and upward expansion of the PCF secondary to an increased tentorial slope serves to explain the possible mechanism of cerebellar herniation in patients with CS. PMID:26246091

  10. Posterior Parietal Cortex Drives Inferotemporal Activations During Three-Dimensional Object Vision

    PubMed Central

    Van Dromme, Ilse C.; Premereur, Elsie; Verhoef, Bram-Ernst; Vanduffel, Wim; Janssen, Peter

    2016-01-01

    The primate visual system consists of a ventral stream, specialized for object recognition, and a dorsal visual stream, which is crucial for spatial vision and actions. However, little is known about the interactions and information flow between these two streams. We investigated these interactions within the network processing three-dimensional (3D) object information, comprising both the dorsal and ventral stream. Reversible inactivation of the macaque caudal intraparietal area (CIP) during functional magnetic resonance imaging (fMRI) reduced fMRI activations in posterior parietal cortex in the dorsal stream and, surprisingly, also in the inferotemporal cortex (ITC) in the ventral visual stream. Moreover, CIP inactivation caused a perceptual deficit in a depth-structure categorization task. CIP-microstimulation during fMRI further suggests that CIP projects via posterior parietal areas to the ITC in the ventral stream. To our knowledge, these results provide the first causal evidence for the flow of visual 3D information from the dorsal stream to the ventral stream, and identify CIP as a key area for depth-structure processing. Thus, combining reversible inactivation and electrical microstimulation during fMRI provides a detailed view of the functional interactions between the two visual processing streams. PMID:27082854

  11. Generalizing Swendsen-Wang to sampling arbitrary posterior probabilities.

    PubMed

    Barbu, Adrian; Zhu, Song-Chun

    2005-08-01

    Many vision tasks can be formulated as graph partition problems that minimize energy functions. For such problems, the Gibbs sampler provides a general solution but is very slow, while other methods, such as Ncut and graph cuts are computationally effective but only work for specific energy forms and are not generally applicable. In this paper, we present a new inference algorithm that generalizes the Swendsen-Wang method to arbitrary probabilities defined on graph partitions. We begin by computing graph edge weights, based on local image features. Then, the algorithm iterates two steps. 1) Graph clustering: It forms connected components by cutting the edges probabilistically based on their weights. 2) Graph relabeling: It selects one connected component and flips probabilistically, the coloring of all vertices in the component simultaneously. Thus, it realizes the split, merge, and regrouping of a "chunk" of the graph, in contrast to Gibbs sampler that flips a single vertex. We prove that this algorithm simulates ergodic and reversible Markov chain jumps in the space of graph partitions and is applicable to arbitrary posterior probabilities or energy functions defined on graphs. We demonstrate the algorithm on two typical problems in computer vision--image segmentation and stereo vision. Experimentally, we show that it is 100-400 times faster in CPU time than the classical Gibbs sampler and 20-40 times faster then the DDMCMC segmentation algorithm. For stereo, we compare performance with graph cuts and belief propagation. We also show that our algorithm can automatically infer generative models and obtain satisfactory results (better than the graphic cuts or belief propagation) in the same amount of time. PMID:16119263

  12. Reverse and pseudoreverse cortical sign in thoracolumbar burst fracture: radiologic description and distinction—a propos of three cases

    PubMed Central

    Orndorff, Douglas G.; Jagannathan, Jay; Dumont, Aaron

    2008-01-01

    In thoracolumbar burst fracture the “reverse cortical sign” is a known entity that corresponds to a fragment of the posterior wall that has been flipped 180° with the cancellous surface of the fragment facing posteriorly in the canal and the cortical surface (posterior wall) facing anteriorly. The identification of such reverse cortical fragment is crucial as ligamentotaxis is classically contraindicated as the posterior longitudinal ligament is ruptured. Recognition of such a flipped cortical fragment has relied so far on the axial CT. The advent of CT scans with sagittal reconstruction has allowed us to better describe such entities that have received little attention in the literature. The goal of this report was therefore to describe the appearance of the reverse cortical sign and its likes as they can appear on axial CT scans, sagittal reconstructions and MRI. During 1-year practice at our institution we had to treat three patients with thoracolumbar burst fracture associated with what looked like a reverse cortical sign on the axial CT scans. Further analysis of the sagittal reconstruction CT could differentiate the true reverse cortical sign from a new entity that we coined “the pseudoreverse cortical sign” as observed in two out of the three cases. In the pseudo reverse cortical sign what appears to be a flipped piece of posterior vertebral body is actually part of the superior or inferior endplate that is depressed into the comminuted vertebral body. In such cases the posterior longitudinal ligament appears to be in continuity and therefore such fracture can theoretically be treated with posterior ligamentotaxis as evidenced in one of our case. Careful analysis of the CT scan and specifically the sagittal reconstruction and MRI can differentiate two separate entities that may correspond to a different severity injury. PMID:19082845

  13. Mutations in FLVCR1 Cause Posterior Column Ataxia and Retinitis Pigmentosa

    PubMed Central

    Rajadhyaksha, Anjali M.; Elemento, Olivier; Puffenberger, Erik G.; Schierberl, Kathryn C.; Xiang, Jenny Z.; Putorti, Maria L.; Berciano, José; Poulin, Chantal; Brais, Bernard; Michaelides, Michel; Weleber, Richard G.; Higgins, Joseph J.

    2010-01-01

    The study of inherited retinal diseases has advanced our knowledge of the cellular and molecular mechanisms involved in sensory neural signaling. Dysfunction of two specific sensory modalities, vision and proprioception, characterizes the phenotype of the rare, autosomal-recessive disorder posterior column ataxia and retinitis pigmentosa (PCARP). Using targeted DNA capture and high-throughput sequencing, we analyzed the entire 4.2 Mb candidate sequence on chromosome 1q32 to find the gene mutated in PCARP in a single family. Employing comprehensive bioinformatic analysis and filtering, we identified a single-nucleotide coding variant in the feline leukemia virus subgroup C cellular receptor 1 (FLVCR1), a gene encoding a heme-transporter protein. Sanger sequencing confirmed the FLVCR1 mutation in this family and identified different homozygous missense mutations located within the protein's transmembrane channel segment in two other unrelated families with PCARP. To determine whether the selective pathologic features of PCARP correlated with FLVCR1 expression, we examined wild-type mouse Flvcr1 mRNA levels in the posterior column of the spinal cord and the retina via quantitative real-time reverse-transcriptase PCR. The Flvcr1 mRNA levels were most abundant in the retina, followed by the posterior column of the spinal cord and other brain regions. These results suggest that aberrant FLVCR1 causes a selective degeneration of a subpopulation of neurons in the retina and the posterior columns of the spinal cord via dysregulation of heme or iron homeostasis. This finding broadens the molecular basis of sensory neural signaling to include common mechanisms that involve proprioception and vision. PMID:21070897

  14. Paratrooper's Ankle Fracture: Posterior Malleolar Fracture

    PubMed Central

    Young, Ki Won; Cho, Jae Ho; Kim, Hyung Seuk; Cho, Hun Ki; Lee, Kyung Tai

    2015-01-01

    Background We assessed the frequency and types of ankle fractures that frequently occur during parachute landings of special operation unit personnel and analyzed the causes. Methods Fifty-six members of the special force brigade of the military who had sustained ankle fractures during parachute landings between January 2005 and April 2010 were retrospectively analyzed. The injury sites and fracture sites were identified and the fracture types were categorized by the Lauge-Hansen and Weber classifications. Follow-up surveys were performed with respect to the American Orthopedic Foot and Ankle Society ankle-hindfoot score, patient satisfaction, and return to preinjury activity. Results The patients were all males with a mean age of 23.6 years. There were 28 right and 28 left ankle fractures. Twenty-two patients had simple fractures and 34 patients had comminuted fractures. The average number of injury and fractures sites per person was 2.07 (116 injuries including a syndesmosis injury and a deltoid injury) and 1.75 (98 fracture sites), respectively. Twenty-three cases (41.07%) were accompanied by posterior malleolar fractures. Fifty-five patients underwent surgery; of these, 30 had plate internal fixations. Weber type A, B, and C fractures were found in 4, 38, and 14 cases, respectively. Based on the Lauge-Hansen classification, supination-external rotation injuries were found in 20 cases, supination-adduction injuries in 22 cases, pronation-external rotation injuries in 11 cases, tibiofibular fractures in 2 cases, and simple medial malleolar fractures in 2 cases. The mean follow-up period was 23.8 months, and the average follow-up American Orthopedic Foot and Ankle Society ankle-hindfoot score was 85.42. Forty-five patients (80.36%) reported excellent or good satisfaction with the outcome. Conclusions Posterior malleolar fractures occurred in 41.07% of ankle fractures sustained in parachute landings. Because most of the ankle fractures in parachute injuries were

  15. Reverse Transfer in Australia

    ERIC Educational Resources Information Center

    Moodie, Gavin

    2004-01-01

    This article considers national Australian data on reverse transfer--the transfer of students from bachelor programs or higher to sub baccalaureate programs, institutions and sectors. It finds that previous studies have overstated the prevalence and perhaps also the significance of reverse transfer. The data are not good, but the best conclusion…

  16. Quantum reverse hypercontractivity

    SciTech Connect

    Cubitt, Toby; Kastoryano, Michael; Montanaro, Ashley; Temme, Kristan

    2015-10-15

    We develop reverse versions of hypercontractive inequalities for quantum channels. By generalizing classical techniques, we prove a reverse hypercontractive inequality for tensor products of qubit depolarizing channels. We apply this to obtain a rapid mixing result for depolarizing noise applied to large subspaces and to prove bounds on a quantum generalization of non-interactive correlation distillation.

  17. Justice and Reverse Discrimination.

    ERIC Educational Resources Information Center

    Goldman, Alan H.

    Defining reverse discrimination as hiring or admissions decisions based on normally irrelevant criteria, this book develops principles of rights, compensation, and equal opportunity applicable to the reverse discrimination issue. The introduction defines the issue and discusses deductive and inductive methodology as applied to reverse…

  18. Reverse Discrimination: Recent Cases.

    ERIC Educational Resources Information Center

    Steinhilber, August W.

    This paper discusses reverse discrimination cases with particular emphasis on Bakke v. Regents of University of California and those cases which preceded it. A brief history is given of court cases used by opponents and proponents in the discussion of reverse discrimination. Legal theory and a discussion of court cases that preceded Bakke follow.…

  19. Ultrasonic Time Reversal Mirrors

    NASA Astrophysics Data System (ADS)

    Fink, Mathias; Montaldo, Gabriel; Tanter, Mickael

    2004-11-01

    For more than ten years, time reversal techniques have been developed in many different fields of applications including detection of defects in solids, underwater acoustics, room acoustics and also ultrasound medical imaging and therapy. The essential property that makes time reversed acoustics possible is that the underlying physical process of wave propagation would be unchanged if time were reversed. In a non dissipative medium, the equations governing the waves guarantee that for every burst of sound that diverges from a source there exists in theory a set of waves that would precisely retrace the path of the sound back to the source. If the source is pointlike, this allows focusing back on the source whatever the medium complexity. For this reason, time reversal represents a very powerful adaptive focusing technique for complex media. The generation of this reconverging wave can be achieved by using Time Reversal Mirrors (TRM). It is made of arrays of ultrasonic reversible piezoelectric transducers that can record the wavefield coming from the sources and send back its time-reversed version in the medium. It relies on the use of fully programmable multi-channel electronics. In this paper we present some applications of iterative time reversal mirrors to target detection in medical applications.

  20. Isolated posterior capsular rupture following blunt head trauma

    PubMed Central

    Mansour, Ahmad M; Jaroudi, Mahmoud O; Hamam, Rola N; Maalouf, Fadi C

    2014-01-01

    Closed-globe traumatic cataract is not uncommon in males in the pediatric age group. However, there is a relative paucity of literature on isolated posterior lens capsule rupture associated with closed-globe traumatic cataract. We report a case of a 6-year-old boy who presented with white cataract 1 day after blunt trauma to the forehead associated with posterior capsular rupture that was detected by B-scan ultrasonography preoperatively. No stigmata of trauma outside the posterior capsule could be detected by slit-lamp exam, funduscopy, and optical coherence tomography. Phacoemulsification with posterior chamber intraocular lens implant was performed 24 hours after trauma, with the patient achieving 6/6 visual acuity 1 week and 6 months after surgery. Our case is unique, being the youngest (amblyogenic age) to be reported, with prompt surgical intervention, and with no signs of trauma outside the posterior capsule. PMID:25506201

  1. Emerging Techniques for Posterior Fixation of the Lumbar Spine.

    PubMed

    Verma, Kushagra; Boniello, Anthony; Rihn, Jeffrey

    2016-06-01

    Pedicle screw fixation is the preferred method of posterior fusion in lumbar spinal surgery. The technique provides three-column support of the vertebrae, contributing to the biomechanical strength of the construct. However, open pedicle screw fixation often necessitates wide posterior exposure and dissection with soft-tissue disruption of the facet joint. Alternative posterior fixation techniques have been developed to reduce surgical time, soft-tissue dissection, disruption of the adjacent facet joint capsule, neurologic risk, and implant cost. Results of these techniques are comparable to those of standard pedicle screw fixation systems. Certain patients, especially those at a lower risk of nonunion or those who require posterior fixation only as an adjunct to anterior column support, may benefit from the shorter surgical time and limited posterior exposure of the alternative techniques. However, the decreased rigidity of these alternative constructs can result in excessive motion, which can lead to nonunion and early hardware failure. PMID:27077477

  2. Role of posterior hypothalamus in hypobaric hypoxia induced pulmonary edema.

    PubMed

    Sharma, R K; Choudhary, R C; Reddy, M K; Ray, A; Ravi, K

    2015-01-01

    To investigate the role of posterior hypothalamus and central neurotransmitters in the pulmonary edema due to hypobaric hypoxia, rats were placed in a high altitude simulation chamber (barometric pressure-294.4 mmHg) for 24 h. Exposure to hypobaric hypoxia resulted in increases in mean arterial blood pressure, renal sympathetic nerve activity, right ventricular systolic pressure, lung wet to dry weight ratio and Evans blue dye leakage. There was a significant attenuation in these responses to hypobaric hypoxia (a) after lesioning posterior hypothalamus and (b) after chronic infusion of GABAA receptor agonist muscimol into posterior hypothalamus. No such attenuation was evident with the chronic infusion of the nitric oxide donor SNAP into the posterior hypothalamus. It is concluded that in hypobaric hypoxia, there is over-activity of posterior hypothalamic neurons probably due to a local decrease in GABA-ergic inhibition which increases the sympathetic drive causing pulmonary hypertension and edema. PMID:25448396

  3. Reversible Shape Memory

    NASA Astrophysics Data System (ADS)

    Zhou, Jing; Li, Qiaoxi; Turner, Sara; Brosnan, Sarah; Tippets, Cary; Carrillo, Jan-Michael; Nykypnachuk, Dmytro; Gang, Oleg; Dobrynin, Andrey; Lopez, Rene; Ashby, Valerie; Sheiko, Sergei

    2014-03-01

    Reversible shape memory has been achieved on various shapes, e.g. hairpin, origami, coil, robotic gripper and flow rate control device, allowing for multiple switching between encoded shapes without applying any external force. Also, the reversible photonic structure molded in dielectric elastomers has been designed. Maximum reversibility can be achieved by tuning the crosslinking density and the degree of crystallinity of semi-crystalline elastomers. Different crystallization protocols including isothermal and cooling crystallization have been applied to develop a universal picture integrating different shape memory (SM) behaviors: conventional one-way SM, two-way reversible SM, and one-way reversible SM. Acknowledge financial support from the NSF DMR-1122483, DMR- 1004576, and DMR-1206957.

  4. Posterior Probability Matching and Human Perceptual Decision Making

    PubMed Central

    Murray, Richard F.; Patel, Khushbu; Yee, Alan

    2015-01-01

    Probability matching is a classic theory of decision making that was first developed in models of cognition. Posterior probability matching, a variant in which observers match their response probabilities to the posterior probability of each response being correct, is being used increasingly often in models of perception. However, little is known about whether posterior probability matching is consistent with the vast literature on vision and hearing that has developed within signal detection theory. Here we test posterior probability matching models using two tools from detection theory. First, we examine the models’ performance in a two-pass experiment, where each block of trials is presented twice, and we measure the proportion of times that the model gives the same response twice to repeated stimuli. We show that at low performance levels, posterior probability matching models give highly inconsistent responses across repeated presentations of identical trials. We find that practised human observers are more consistent across repeated trials than these models predict, and we find some evidence that less practised observers more consistent as well. Second, we compare the performance of posterior probability matching models on a discrimination task to the performance of a theoretical ideal observer that achieves the best possible performance. We find that posterior probability matching is very inefficient at low-to-moderate performance levels, and that human observers can be more efficient than is ever possible according to posterior probability matching models. These findings support classic signal detection models, and rule out a broad class of posterior probability matching models for expert performance on perceptual tasks that range in complexity from contrast discrimination to symmetry detection. However, our findings leave open the possibility that inexperienced observers may show posterior probability matching behaviour, and our methods provide new tools

  5. Facilitating text reading in posterior cortical atrophy

    PubMed Central

    Rajdev, Kishan; Shakespeare, Timothy J.; Leff, Alexander P.; Crutch, Sebastian J.

    2015-01-01

    Objective: We report (1) the quantitative investigation of text reading in posterior cortical atrophy (PCA), and (2) the effects of 2 novel software-based reading aids that result in dramatic improvements in the reading ability of patients with PCA. Methods: Reading performance, eye movements, and fixations were assessed in patients with PCA and typical Alzheimer disease and in healthy controls (experiment 1). Two reading aids (single- and double-word) were evaluated based on the notion that reducing the spatial and oculomotor demands of text reading might support reading in PCA (experiment 2). Results: Mean reading accuracy in patients with PCA was significantly worse (57%) compared with both patients with typical Alzheimer disease (98%) and healthy controls (99%); spatial aspects of passages were the primary determinants of text reading ability in PCA. Both aids led to considerable gains in reading accuracy (PCA mean reading accuracy: single-word reading aid = 96%; individual patient improvement range: 6%–270%) and self-rated measures of reading. Data suggest a greater efficiency of fixations and eye movements under the single-word reading aid in patients with PCA. Conclusions: These findings demonstrate how neurologic characterization of a neurodegenerative syndrome (PCA) and detailed cognitive analysis of an important everyday skill (reading) can combine to yield aids capable of supporting important everyday functional abilities. Classification of evidence: This study provides Class III evidence that for patients with PCA, 2 software-based reading aids (single-word and double-word) improve reading accuracy. PMID:26138948

  6. Decoding Trajectories from Posterior Parietal Cortex Ensembles

    PubMed Central

    Mulliken, Grant H.; Musallam, Sam; Andersen, Richard A.

    2009-01-01

    High-level cognitive signals in the posterior parietal cortex (PPC) have previously been used to decode the intended endpoint of a reach, providing the first evidence that PPC can be used for direct control of a neural prosthesis (Musallam et al., 2004). Here we expand on this work by showing that PPC neural activity can be harnessed to estimate not only the endpoint but also to continuously control the trajectory of an end effector. Specifically, we trained two monkeys to use a joystick to guide a cursor on a computer screen to peripheral target locations while maintaining central ocular fixation. We found that we could accurately reconstruct the trajectory of the cursor using a relatively small ensemble of simultaneously recorded PPC neurons. Using a goal-based Kalman filter that incorporates target information into the state-space, we showed that the decoded estimate of cursor position could be significantly improved. Finally, we tested whether we could decode trajectories during closed-loop brain control sessions, in which the real-time position of the cursor was determined solely by a monkey’s neural activity in PPC. The monkey learned to perform brain control trajectories at 80% success rate(for 8 targets) after just 4–5 sessions. This improvement in behavioral performance was accompanied by a corresponding enhancement in neural tuning properties (i.e., increased tuning depth and coverage of encoding parameter space) as well as an increase in off-line decoding performance of the PPC ensemble. PMID:19036985

  7. Automatic quantification of posterior capsule opacification

    NASA Astrophysics Data System (ADS)

    Barman, Sarah A.; Uyyanonvara, Bunyarit; Boyce, James F.; Sanguinetti, Giorgia; Hollick, Emma J.; Meacock, William R.; Spalton, David J.; Paplinski, Andrew P.

    2000-06-01

    After Cataract surgery where a plastic implant lens is implanted into the eye to replace the natural lens, many patients suffer from cell growth across a membrane situated at the back of the lens which degrades their vision. The cell growth is known as Posterior Capsule Opacification (or PCO). It is important to be able to quantify PCO so that the effect of different implant lens types and surgical techniques may be evaluated. Initial results obtained using a neural network to detect PCO from implant lenses are compared to an established but less automated method of detection, which segments the images using texture segmentation in conjunction with co- occurrence matrices. Tests show that the established method performs well in clinical validation and repeatability trials. The requirement to use a neural network to analyze the implant lens images evolved from the analysis of over 1000 images using the established co-occurrence matrix segmentation method. The work shows that a method based on neural networks is a promising tool to automate the procedure of calculating PCO.

  8. The posterior glottis: structural and clinical considerations.

    PubMed

    Kotby, M N; Kamal, E; El-Makhzangy, A; Nabil Khattab, A; Milad, P

    2012-11-01

    Despite the presence of a number of good publications during the past two decades, the posterior glottis (PG) is still not clearly appreciated in clinical laryngological practice. This study focuses on searching the literature to find out the present day awareness of the PG, as well as highlighting some of its clinical features. The investigation proceeds with two main sections: (1) critical analysis of the literature on the PG during the last 50 years (2) describing the clinical appearance and behavior of the PG in 100 normal subjects. Results of section 1 illustrate the limited awareness in the literature of the existence of PG as a distinct part of the human larynx. Results of section 2 illustrate some misconcepts related to the PG as inter-arytenoid pachydermia, change of voice with lesions in the PG. Discussion elaborates on the significance of the findings and attempts to clarify certain misconcepts about the PG, its structure, function, and clinical features. In the light of the data collected from the literature regarding the dimensions of the PG, a set of recommendations were proposed regarding the optimal sizes of the endotracheal tubes in both sexes. PMID:22614807

  9. Posterior Cruciate Ligament Retention versus Posterior Stabilization for Total Knee Arthroplasty: A Meta-Analysis

    PubMed Central

    Wang, Ying; Bian, Yanyan; Feng, Bin; Weng, Xisheng

    2016-01-01

    Introduction Although being debated for many years, the superiority of posterior cruciate-retaining (CR) total knee arthroplasty (TKA) and posterior-stabilized (PS) TKA remains controversial. We compare the knee scores, post-operative knee range of motion (ROM), radiological outcomes about knee kinematic and complications between CR TKA and PS TKA. Methods Literature published up to August 2015 was searched in PubMed, Embase and Cochrane databases, and meta-analysis was performed using the software, Review Manager version 5.3. Results Totally 14 random control trials (RCTs) on this topic were included for the analysis, which showed that PS and CR TKA had no significant difference in Knee Society knee Score (KSS), pain score (KSPS), Hospital for Special Surgery score (HSS), kinematic characteristics including postoperative component alignment, tibial posterior slope and joint line, and complication rate. However, PS TKA is superior to CR TKA regarding post-operative knee range of motion (ROM) [Random Effect model (RE), Mean Difference (MD) = -7.07, 95% Confidential Interval (CI) -10.50 to -3.65, p<0.0001], improvement of ROM (Fixed Effect model (FE), MD = -5.66, 95% CI -10.79 to -0.53, p = 0.03) and femoral-tibial angle [FE, MD = 0.85, 95% CI 0.46 to 1.25, p<0.0001]. Conclusions There are no clinically relevant differences between CR and PS TKA in terms of clinical, functional, radiological outcome, and complications, while PS TKA is superior to CR TKA in respects of ROM, while whether this superiority matters or not in clinical practice still needs further investigation and longer follow-up. PMID:26824368

  10. Supplemental morphine infusion into the posterior ventral tegmentum extends the satiating effects of self-administered intravenous heroin

    PubMed Central

    Steidl, S; Myal, S; Wise, RA

    2015-01-01

    Rats learn to self-administer intravenous heroin; well-trained animals lever-press at a slow and regular pace over a wide range of intravenous doses. The pauses between successive earned infusions are proportional to the dose of the previous injection and are thought to reflect periods of drug satiety. Rats will also self-administer opiates by microinjection directly into sites in the posterior regions of the ventral tegmentum. To determine if the pauses between self-administered intravenous injections are due to opiate actions in posterior ventral tegmentum, we delivered supplemental morphine directly into this region during intravenous self-administration sessions in well-trained rats. Reverse dialysis of morphine into the posterior ventral tegmentum increased the intervals between earned injections. The inter-response intervals were greatest for infusion into the most posterior ventral tegmental sites, sites in a region variously known as the tail of the ventral tegmental area or as the rostromedial tegmental nucleus. These sites at which morphine prolongs inter-response intervals, correspond to the sites at which opiates have been found most effective in reinforcing instrumental behavior. PMID:25913296

  11. Arthroscopic Repair of Posterior Meniscal Root Tears

    PubMed Central

    Matheny, Lauren; Moulton, Samuel G.; Dean, Chase S.; LaPrade, Robert F.

    2016-01-01

    Objectives: The purpose of this study was to compare subjective clinical outcomes in patients requiring arthroscopic transtibial pullout repair for posterior meniscus root tears of the medial and lateral menisci. We hypothesized that improvement in function and activity level would be similar among patients undergoing lateral and medial meniscal root repairs. Methods: This study was IRB approved. All patients who underwent posterior meniscal root repair by a single orthopaedic surgeon were included in this study. Detailed operative data were documented at surgery. Patients completed a subjective questionnaire, including Lysholm score, Tegner activity scale, WOMAC, SF-12 and patient satisfaction with outcome, which were collected preoperatively and at a minimum of two years postoperatively. Failure was defined as any patient who underwent revision meniscal root repair or partial meniscectomy following the index surgery. Results: There were 50 patients (16 females, 34 males) with a mean age of 37.8 years (range, 16.6-65.7) and a mean BMI of 27.3 (range, 20.5-49.2) included in this study. Fifteen patients underwent lateral meniscus root repair and 35 patients underwent medial meniscus root repair. Three patients who underwent lateral meniscus root repair required revision meniscus root repair surgery, while no patients who underwent medial meniscus root repair required revision surgery (p=0.26). There was a significant difference in preoperative and postoperative Lysholm score (53 vs. 78) (p<0.001), Tegner activity scale (2.0 vs. 4.0) (p=0.03), SF-12 physical component subscale (38 vs. 50) (p=0.001) and WOMAC (36 vs. 8) (p<0.001) for the total population. Median patient satisfaction with outcome was 9 (range, 1-10). There was no significant difference in mean age between lateral and medial root repair groups (32 vs. 40) (p=0.12) or gender (p=0.19). There was no significant difference in gender between lateral and medial root repair groups (p=0.95). There was a

  12. Posterior Cruciate Ligament Reconstruction in Patients with Generalized Joint Laxity

    PubMed Central

    Kim, Sung-Jae; Chang, Ji-Hoon

    2008-01-01

    Generalized joint laxity has been considered a risk factor causing late failure of reconstructed anterior cruciate ligaments, although it is unknown whether that is the case for reconstructed posterior cruciate ligaments. We hypothesized patients with generalized joint laxity, compared with those without laxity, would have similar postoperative knee stability, range of motion, and functional scores after posterior cruciate ligament reconstruction. The Beighton and Horan criteria were used to determine generalized joint laxity. We enrolled 24 patients with generalized joint laxity (Group L) and 29 patients without any positive findings of joint laxity (Group N) matched by gender and age. The average side-by-side differences of posterior tibial translation were 4.72 mm in Group L and 3.63 mm in Group N. We observed no differences in posterior tibial translation with differing graft materials or combined procedures. In Group L the International Knee Documentation Committee score was normal in 12.5% and nearly normal in 45.8% whereas in Group N, 24.1% were normal and 55.2% nearly normal. Patients with generalized joint laxity showed more posterior laxity than patients without joint laxity. Generalized joint laxity therefore appears to be a risk factor associated with posterior laxity after posterior cruciate ligament reconstruction. Level of Evidence: Level III, prognostic study. See the Guidelines for Authors for a complete description of levels of evidence. PMID:18843524

  13. The language profile of Posterior Cortical Atrophy

    PubMed Central

    Crutch, Sebastian J.; Lehmann, Manja; Warren, Jason D.; Rohrer, Jonathan D.

    2015-01-01

    Background Posterior Cortical Atrophy (PCA) is typically considered to be a visual syndrome, primarily characterised by progressive impairment of visuoperceptual and visuospatial skills. However patients commonly describe early difficulties with word retrieval. This paper details the first systematic analysis of linguistic function in PCA. Characterising and quantifying the aphasia associated with PCA is important for clarifying diagnostic and selection criteria for clinical and research studies. Methods Fifteen patients with PCA, 7 patients with logopenic/phonological aphasia (LPA) and 18 age-matched healthy participants completed a detailed battery of linguistic tests evaluating auditory input processing, repetition and working memory, lexical and grammatical comprehension, single word retrieval and fluency, and spontaneous speech. Results Relative to healthy controls, PCA patients exhibited language impairments across all the domains examined, but with anomia, reduced phonemic fluency and slowed speech rate the most prominent deficits. PCA performance most closely resembled that of LPA patients on tests of auditory input processing, repetition and digit span, but was relatively stronger on tasks of comprehension and spontaneous speech. Conclusions The study demonstrates that in addition to the well-reported degradation of vision, literacy and numeracy, PCA is characterised by a progressive oral language dysfunction with prominent word retrieval difficulties. Overlap in the linguistic profiles of PCA and LPA, which are both most commonly caused by Alzheimer’s disease, further emphasises the notion of a phenotypic continuum between typical and atypical manifestations of the disease. Clarifying the boundaries between AD phenotypes has important implications for diagnosis, clinical trial recruitment and investigations into biological factors driving phenotypic heterogeneity in AD. Rehabilitation strategies to ameliorate the phonological deficit in PCA are required

  14. Aspheric versus Spherical Posterior Chamber Intraocular Lenses

    PubMed Central

    Jafarinasab, Mohammad-Reza; Feizi, Sepehr; Baghi, Ahmad-Reza; Ziaie, Hossein; Yaseri, Mehdi

    2010-01-01

    Purpose To compare spherical aberration and contrast sensitivity function following implantation of four different foldable posterior chamber intraocular lenses (IOLs), namely Sensar, Akreos AO, Tecnis, and AcrySof IQ. Methods In this randomized clinical trial, 68 eyes of 68 patients with senile cataracts underwent phacoemulsification and IOL implantation with Sensar (n=17), Akreos AO (n=17), Tecnis (n=17), or AcrySof IQ (n=17). Uncorrected visual acuity (UCVA) and best spectacle-corrected visual acuity (BSCVA), spherical aberration and contrast sensitivity function (CSF) were compared among the study groups, 3 months after surgery. Results There was no significant difference between the study groups in terms of age (P = 0.21). Mean postoperative BSCVA with Sensar, Akreos AO, Tecnis, and AcrySof IQ was 0.15±0.10, 0.12±0.9, 0.08±0.08, and 0.08±0.07 logMAR, respectively (P=0.08). Spherical aberration measured over a 4 mm pupil was significantly higher with Sensar and Akreos AO than the two other IOLs. The difference between Tecnis and AcrySof IQ was significantly in favor of the former IOL. Over a 6 mm pupil, spherical aberrations were comparable with Sensar and Akreos AO, furthermore spherical aberration was also comparable among eyes implanted with Akreos AO, AcrySof IQ, and Tecnis. Sensar yielded significantly inferior results as compared to Acrysof IQ and Tecnis. CSF with Sensar was inferior to the three aspheric IOLs at the majority of spatial frequencies. Tecnis yielded significantly better mesopic CSF at 1.5 and 3 cycles per degree spatial frequencies. Conclusion Tecnis and AcrySof IQ provided significantly better visual function as compared to Sensar and Akreos AO, especially with smaller pupil size. However, this difference diminished with increasing pupil size. PMID:22737364

  15. Technical Note on Modified Posterior Approach to the Hip Joint

    PubMed Central

    Iyer, Krishna Mohan

    2015-01-01

    Introduction: The posterior approach is the most commonly and relatively easy to be used to expose the hip joint. Posterior approaches allow excellent visualization of the entire acetabulum and the upper femoral shaft, and thus they are popular for revision joint replacement surgery particularly in cases where only the femoral component needs to be replaced. There may be a higher dislocation rate with minimal movement as compared to anterior approaches if the posterior approach is used in fractured neck of femur surgery in demented or elderly bedridden patients who often lie crouched in bed with their hips in a flexed and adducted position. The expected purpose of this modification of the Posterior Approach to the Hip Joint is to overcome the fear of dislocation and hence combine the advantages of the Posterior route with greater stability. Technique: The author’s original paper written 30 years ago (Iyer, 1981) presented an original technique devised to confer greater stability to the hip joint posteriorly to minimize the greater incidence of dislocation which has been reported extensively in literature. The technique involves an osteotomy of the posterior overhanging part of the greater trochanter to include the insertions of the short lateral rotators along with the posterior third of the gluteus medius, which can then be turned back in one piece like the page of a book to include the capsule of the hip joint. This gives wide exposure of the posterior lip of the acetabulum and is relatively bloodless in its exposure. This approach is very useful in the elderly particularly demented patients requiring a hemiarthroplasty and also in primary and revision total hip replacement. This approach has been tested in cadavers to conclude the greater stability given as compared to the routine resuture or reattachment of the short lateral rotators. Conclusion: The modified technique provides for greater stability as compared to the Southern Approach. PMID:27299026

  16. Detection of Neisseria gonorrhoeae Isolates from Tonsils and Posterior Oropharynx

    PubMed Central

    Whiley, D. M.; Lee, D. M.; Snow, A. F.; Fairley, C. K.; Peel, J.; Bradshaw, C. S.; Hocking, J. S.; Lahra, M. M.; Chen, M. Y.

    2015-01-01

    We examined the factors influencing gonorrhea detection at the pharynx. One hundred men infected with Neisseria gonorrhoeae were swabbed from the tonsils and posterior oropharynx. N. gonorrhoeae was reisolated from the tonsils and posterior oropharynx in 62% and 52%, respectively (P = 0.041). Culture positivity was greater with higher gonococcal DNA loads at the tonsils (P = 0.001) and oropharynx (P < 0.001). N. gonorrhoeae can be cultured from the tonsils and posterior oropharynx with greater isolation rates where gonococcal loads are higher. PMID:26292303

  17. Anatomic Double-Bundle Posterior Cruciate Ligament Reconstruction.

    PubMed

    Chahla, Jorge; Nitri, Marco; Civitarese, David; Dean, Chase S; Moulton, Samuel G; LaPrade, Robert F

    2016-02-01

    The posterior cruciate ligament (PCL) is known to be the main posterior stabilizer of the knee. Anatomic single-bundle PCL reconstruction, focusing on reconstruction of the larger anterolateral bundle, is the most commonly performed procedure. Because of the residual posterior and rotational tibial instability after the single-bundle procedure and the inability to restore the normal knee kinematics, an anatomic double-bundle PCL reconstruction has been proposed in an effort to re-create the native PCL footprint more closely and to restore normal knee kinematics. We detail our technique for an anatomic double-bundle PCL reconstruction using Achilles and anterior tibialis tendon allografts. PMID:27284530

  18. The Simultaneous Modeling Technique: closing gaps in posteriors.

    PubMed

    Scolavino, Salvatore; Paolone, Gaetano; Orsini, Giovanna; Devoto, Walter; Putignano, Angelo

    2016-01-01

    Direct posterior restorations represent a widespread procedure in daily practice. Occlusal layering is often considered a complex task, generally not predictable and often requiring several occlusal adjustments. Moreover, direct posterior restorations are time consuming, as many small increments must be applied and cured individually to control shrinkage stress. Several authors have proposed different material layering techniques for posteriors. The authors of this article propose a simplified approach, which primarily aims to help the clinician perform quick, simple, predictable, and natural-looking occlusal modeling, reducing the need for occlusal adjustments. PMID:26835524

  19. Posterior Wall Blowout in Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Mitchell, Justin J.; Dean, Chase S.; Chahla, Jorge; Menge, Travis J.; Cram, Tyler R.; LaPrade, Robert F.

    2016-01-01

    Violation of the posterior femoral cortex, commonly referred to as posterior wall blowout, can be a devastating intraoperative complication in anterior cruciate ligament (ACL) reconstruction and lead to loss of graft fixation or early graft failure. If cortical blowout occurs despite careful planning and adherence to proper surgical technique, a thorough knowledge of the anatomy and alternative fixation techniques is imperative to ensure optimal patient outcomes. This article highlights anatomic considerations for femoral tunnel placement in ACL reconstruction and techniques for avoidance and salvage of a posterior wall blowout. PMID:27335885

  20. Reversible shape memory

    NASA Astrophysics Data System (ADS)

    Sheiko, Sergei; Zhou, Jing; White, Sarah; Ashby, Valerie

    2012-02-01

    An ``Achilles' heel'' of shape memory materials is that shape transformations triggered by an external stimulus are usually irreversible. Here we present a new concept of reversible transitions between two well-defined shapes by controlling hierarchic crystallization of a dual-network elastomer. The reversibility was demonstrated for different types of shape transformations including rod bending, winding of a helical coil, and widening an aperture. The distinct feature of the reversible shape alterations is that both counter-shapes are infinitely stable at a temperature of exploitation. Shape reversibility is highly desirable property in many practical applications such as non-surgical removal of a previously inserted catheter and handfree wrapping up of an earlier unraveled solar sail on a space shuttle.

  1. Tubal ligation reversal

    MedlinePlus

    ... Fernandez H, Gervaise A. Tubal anastomosis after tubal sterilization: a review. Arch Gynecol Obstet . 2011 May;283( ... Berger GS, Zerden ML. Pregnancy success after hysteroscopic sterilization reversal. Obstet Gynecol . 2014 Dec;124(6):1183- ...

  2. Giant rodlike reversed micelles

    SciTech Connect

    Yu, Z.J.; Neuman, R.D. )

    1994-05-04

    Herein we report that sodium bis(2-ethylhexyl)phosphate, which is similar in structure to the classical surfactant sodium bis(2-ethylhexyl)sulfosuccinate (AOT), forms very large rodlike reversed micelles and that their size can be even much larger if water is removed from the apolar solution. We further suggest that long-range electrostatic interactions are the primary driving force for the formation of giant reversed micelles. 19 refs., 3 figs.

  3. Posterior decompression with instrumented fusion for thoracic myelopathy caused by ossification of the posterior longitudinal ligament.

    PubMed

    Yamazaki, Masashi; Okawa, Akihiko; Fujiyoshi, Takayuki; Furuya, Takeo; Koda, Masao

    2010-05-01

    We evaluated the clinical results of posterior decompression with instrumented fusion (PDF) for thoracic myelopathy due to ossification of the posterior longitudinal ligament (OPLL). A total of 24 patients underwent PDF, and their surgical outcomes were evaluated by the Japanese Orthopaedic Association (JOA) scores (0-11 points) and by recovery rates calculated at 3, 6, 9 and 12 months after surgery and at a mean final follow-up of 4 years and 5 months. The mean JOA score before surgery was 3.7 points. Although transient paralysis occurred immediately after surgery in one patient (3.8%), all patients showed neurological recovery at the final follow-up with a mean JOA score of 8.0 points and a mean recovery rate of 58.1%. The mean recovery rate at 3, 6, 9 and 12 months after surgery was 36.7, 48.8, 54.0 and 56.8%, respectively. The median time point that the JOA score reached its peak value was 9 months after surgery. No patient chose additional anterior decompression surgery via thoracotomy. The present findings demonstrate that despite persistent anterior impingement of the spinal cord by residual OPLL, PDF can result in considerable neurological recovery with a low risk of postoperative paralysis. Since neurological recovery progresses slowly after PDF, we suggest that additional anterior decompression surgery is not desirable during the early stage of recovery. PMID:20049486

  4. On thermodynamic and microscopic reversibility

    SciTech Connect

    Crooks, Gavin E.

    2011-07-12

    The word 'reversible' has two (apparently) distinct applications in statistical thermodynamics. A thermodynamically reversible process indicates an experimental protocol for which the entropy change is zero, whereas the principle of microscopic reversibility asserts that the probability of any trajectory of a system through phase space equals that of the time reversed trajectory. However, these two terms are actually synonymous: a thermodynamically reversible process is microscopically reversible, and vice versa.

  5. Magnetic source imaging in posterior cortex epilepsies.

    PubMed

    Badier, Jean-Michel; Bartolomei, Fabrice; Chauvel, Patrick; Bénar, Christian-George; Gavaret, Martine

    2015-01-01

    Posterior cortex epilepsies (PCE) are characterized by less satisfying postoperative results than temporal lobe epilepsies and are thus challenging for non-invasive presurgical investigations. The objective of this study was to evaluate the performance of magnetic source imaging (MSI) in PCE, validating the results by the SEEG (stereoelectroencephalography) definition of irritative and epileptogenic zones (IZ and EZ). Fourteen PCE surgery candidates were investigated using MSI and SEEG. LCMV (Linearly Constrained Minimum Variance) and MUSIC algorithms were used. IZ was quantified using a semi-automatic detection of interictal spikes. EZ was quantified using the epileptogenicity index (EI) method that accounts for both the propensity of a brain area to generate rapid discharges and the time for this area to get involved in the seizure. EI values range from 0 (no epileptogenicity) to 1 (maximal epileptogenicity). Levels of concordance between MSI and IZ, MSI and EZ were determined as follows: A = localized on MSI and SEEG for the site of value 1 (IZ and EZ quantification), B = localized on MSI and SEEG for a part of the IZ or a structure involved in the EZ (without the maximal value 1), C = localized on MSI and not SEEG, D = localized on SEEG and not MSI, E = localized on MSI and SEEG, discordant for site. Five PCE cases were characterized by focal IZ, nine by distributed IZ between several distant brain areas. MSI allowed to determinate IZ in 4/5 focal IZ cases. In case of distributed IZ, levels of concordance were A (2 cases), B (4 cases) and D (3 cases). In most distributed cases, MSI allowed to localize only a part of the IZ. Medial temporal involvement in the IZ was frequent (9/12 cases) and not evidenced by MSI. The brain area that demonstrated the maximal value of EI was shown by MSI in four out of five (80 %) focal IZ cases, in two out of nine (22 %) distributed cases. MSI results depend on IZ characteristics. A distributed IZ organization

  6. Effect of Posterior Tibial Slope on Flexion and Anterior-Posterior Tibial Translation in Posterior Cruciate-Retaining Total Knee Arthroplasty.

    PubMed

    Chambers, Andrew W; Wood, Addison R; Kosmopoulos, Victor; Sanchez, Hugo B; Wagner, Russell A

    2016-01-01

    Reduced posterior tibial slope (PTS) and posterior tibiofemoral translation (PTFT) in posterior cruciate-retaining (PCR) total knee arthroplasty (TKA) may result in suboptimal flexion. We evaluated the relationship between PTS, PTFT, and total knee flexion after PCR TKA in a cadaveric model. We performed a balanced PCR TKA using 9 transfemoral cadaver specimens and changed postoperative PTS in 1° increments. We measured maximal flexion and relative PTFT at maximal flexion. We determined significant changes in flexion and PTFT as a function of PTS. Findings showed an average increase in flexion of 2.3° and average PTFT increase of 1mm per degree of PTS increase when increasing PTS from 1° to 4° (P<.05). Small initial increases in PTS appear to significantly increase knee flexion and PTFT. PMID:26476469

  7. Posterior Urethral Valve: An Unusual Cause of Primary Male Infertility

    PubMed Central

    Agbugui, Jude Orumuah; Omokhudu, Oisamoren

    2015-01-01

    Background Posterior urethral valve presenting in adulthood is uncommon. This can be an unusual cause of primary male infertility as a result of abnormalities in sexual function. Case Presentation This report describes a 40 year old man who presented to us on account of inability to impregnate his wife after 2 years of marriage. History revealed poor stream of urine since childhood and passage of scanty ejaculate during intercourse. A micturating cystourethrogram revealed dilated posterior urethra in keeping with posterior urethral valves. Endoscopic valve ablation was done with subsequent improvement in ejaculate volume and urine stream. His spouse achieved pregnancy thereafter. Conclusion In this report, it was found that adult posterior urethral valve though uncommon may be a cause of male infertility. Restoration of fertility potential can be achieved following valve ablation. PMID:25927029

  8. Free posterior tibial flap reconstruction for hypopharyngeal squamous cell carcinoma

    PubMed Central

    2014-01-01

    Objectives The aim of this article was to determine outcomes in patients with squamous cell carcinoma of the hypopharynx (SCCHP) in whom the free posterior tibial flap was used for primary reconstruction of hypopharynx defects after cancer resection. Subjects and methods Between August 2009 and February 2012, 10 patients with SCCHP underwent posterior tibial flap reconstruction for hypopharynx defects. The corresponding clinical data were retrospectively collected and analyzed. Results Despite the multistep and time-consuming procedure, the posterior tibial flap survival rate was 100%. Operation-induced complications did not occur in four patients. Six patients developed postoperative hypoproteinemia, four patients developed postoperative pulmonary infections, and four patients developed pharyngeal fistula. The pharyngeal and laryngeal functions of all patients were preserved. Conclusion Our experience demonstrates that the posterior tibial flap is a safe and reliable choice for the reconstruction of hypopharynx defects. PMID:24884631

  9. Abnormalities of fixation, saccade and pursuit in posterior cortical atrophy.

    PubMed

    Shakespeare, Timothy J; Kaski, Diego; Yong, Keir X X; Paterson, Ross W; Slattery, Catherine F; Ryan, Natalie S; Schott, Jonathan M; Crutch, Sebastian J

    2015-07-01

    The clinico-neuroradiological syndrome posterior cortical atrophy is the cardinal 'visual dementia' and most common atypical Alzheimer's disease phenotype, offering insights into mechanisms underlying clinical heterogeneity, pathological propagation and basic visual phenomena (e.g. visual crowding). Given the extensive attention paid to patients' (higher order) perceptual function, it is surprising that there have been no systematic analyses of basic oculomotor function in this population. Here 20 patients with posterior cortical atrophy, 17 patients with typical Alzheimer's disease and 22 healthy controls completed tests of fixation, saccade (including fixation/target gap and overlap conditions) and smooth pursuit eye movements using an infrared pupil-tracking system. Participants underwent detailed neuropsychological and neurological examinations, with a proportion also undertaking brain imaging and analysis of molecular pathology. In contrast to informal clinical evaluations of oculomotor dysfunction frequency (previous studies: 38%, current clinical examination: 33%), detailed eyetracking investigations revealed eye movement abnormalities in 80% of patients with posterior cortical atrophy (compared to 17% typical Alzheimer's disease, 5% controls). The greatest differences between posterior cortical atrophy and typical Alzheimer's disease were seen in saccadic performance. Patients with posterior cortical atrophy made significantly shorter saccades especially for distant targets. They also exhibited a significant exacerbation of the normal gap/overlap effect, consistent with 'sticky fixation'. Time to reach saccadic targets was significantly associated with parietal and occipital cortical thickness measures. On fixation stability tasks, patients with typical Alzheimer's disease showed more square wave jerks whose frequency was associated with lower cerebellar grey matter volume, while patients with posterior cortical atrophy showed large saccadic intrusions

  10. Abnormalities of fixation, saccade and pursuit in posterior cortical atrophy

    PubMed Central

    Kaski, Diego; Yong, Keir X. X.; Paterson, Ross W.; Slattery, Catherine F.; Ryan, Natalie S.; Schott, Jonathan M.; Crutch, Sebastian J.

    2015-01-01

    The clinico-neuroradiological syndrome posterior cortical atrophy is the cardinal ‘visual dementia’ and most common atypical Alzheimer’s disease phenotype, offering insights into mechanisms underlying clinical heterogeneity, pathological propagation and basic visual phenomena (e.g. visual crowding). Given the extensive attention paid to patients’ (higher order) perceptual function, it is surprising that there have been no systematic analyses of basic oculomotor function in this population. Here 20 patients with posterior cortical atrophy, 17 patients with typical Alzheimer’s disease and 22 healthy controls completed tests of fixation, saccade (including fixation/target gap and overlap conditions) and smooth pursuit eye movements using an infrared pupil-tracking system. Participants underwent detailed neuropsychological and neurological examinations, with a proportion also undertaking brain imaging and analysis of molecular pathology. In contrast to informal clinical evaluations of oculomotor dysfunction frequency (previous studies: 38%, current clinical examination: 33%), detailed eyetracking investigations revealed eye movement abnormalities in 80% of patients with posterior cortical atrophy (compared to 17% typical Alzheimer’s disease, 5% controls). The greatest differences between posterior cortical atrophy and typical Alzheimer’s disease were seen in saccadic performance. Patients with posterior cortical atrophy made significantly shorter saccades especially for distant targets. They also exhibited a significant exacerbation of the normal gap/overlap effect, consistent with ‘sticky fixation’. Time to reach saccadic targets was significantly associated with parietal and occipital cortical thickness measures. On fixation stability tasks, patients with typical Alzheimer’s disease showed more square wave jerks whose frequency was associated with lower cerebellar grey matter volume, while patients with posterior cortical atrophy showed large

  11. A rare case of traumatic posterior phacocele with retinal detachment

    PubMed Central

    Sindal, Manavi D; Mourya, Deepesh

    2016-01-01

    Dislocation of crystalline lens into the anterior subconjunctival or subtenon's space is a rare but known complication of blunt trauma. Dislocation into the posterior subtenon's space is even rarer and can be associated with a complication such as occult scleral tear and retinal detachment. We report a case of traumatic posterior subtenon's dislocation of crystalline lens after blunt trauma and its successful surgical management. PMID:26953031

  12. Posterior partially edentulous jaws, planning a rehabilitation with dental implants

    PubMed Central

    Monteiro, Douglas R; Silva, Emily V F; Pellizzer, Eduardo P; Filho, Osvaldo Magro; Goiato, Marcelo C

    2015-01-01

    AIM: To discuss important characteristics of the use of dental implants in posterior quadrants and the rehabilitation planning. METHODS: An electronic search of English articles was conducted on MEDLINE (PubMed) from 1990 up to the period of March 2014. The key terms were dental implants and posterior jaws, dental implants/treatment planning and posterior maxilla, and dental implants/treatment planning and posterior mandible. No exclusion criteria were used for the initial search. Clinical trials, randomized and non randomized studies, classical and comparative studies, multicenter studies, in vitro and in vivo studies, case reports, longitudinal studies and reviews of the literature were included in this review. RESULTS: One hundred and fifty-two articles met the inclusion criteria of treatment planning of dental implants in posterior jaw and were read in their entirety. The selected articles were categorized with respect to their context on space for restoration, anatomic considerations (bone quantity and density), radiographic techniques, implant selection (number, position, diameter and surface), tilted and pterygoid implants, short implants, occlusal considerations, and success rates of implants placed in the posterior region. The results derived from the review process were described under several different topic headings to give readers a clear overview of the literature. In general, it was observed that the use of dental implants in posterior region requires a careful treatment plan. It is important that the practitioner has knowledge about the theme to evaluate the treatment parameters. CONCLUSION: The use of implants to restore the posterior arch presents many challenges and requires a detailed treatment planning. PMID:25610852

  13. Cementoblastoma of posterior maxilla involving the maxillary sinus

    PubMed Central

    Dadhich, Anuj S.; Nilesh, Kumar

    2015-01-01

    Cementoblastoma is a rare neoplasm, representing <1% of all odontogenic tumors. It usually occurs in the posterior mandible and is associated with roots of a mandibular first molar or second premolar. This paper presents a rare case of cementoblastoma in the maxillary posterior region involving the maxillary sinus, in a young female patient. The clinical, radiological, and histopathological features of the lesion are discussed along with a review of previously reported cases in the literature. PMID:26389052

  14. Erupted complex odontoma of the posterior maxilla: A rarity

    PubMed Central

    Verma, Sonika; Arul, A. Sri Kennath J.; Arul, A. Sri Sennath J.; Chitra, S.

    2015-01-01

    Complex odontomas, hamartomas of aborted tooth development, mainly occur in posterior part of the mandible and rarely erupt into the oral cavity. The spontaneous eruption may be associated with pain, inflammation of adjacent soft tissues or recurrent infection. The present case of complex odontoma is of particular interest due to its apparent eruption in the maxillary posterior segment, its association with agenesis of the second molar and impacted third molar; with the lesion being completely asymptomatic. PMID:26604611

  15. Erupted complex odontoma of the posterior maxilla: A rarity.

    PubMed

    Verma, Sonika; Arul, A Sri Kennath J; Arul, A Sri Sennath J; Chitra, S

    2015-08-01

    Complex odontomas, hamartomas of aborted tooth development, mainly occur in posterior part of the mandible and rarely erupt into the oral cavity. The spontaneous eruption may be associated with pain, inflammation of adjacent soft tissues or recurrent infection. The present case of complex odontoma is of particular interest due to its apparent eruption in the maxillary posterior segment, its association with agenesis of the second molar and impacted third molar; with the lesion being completely asymptomatic. PMID:26604611

  16. Isolated posterior high ankle sprain: a report of three cases.

    PubMed

    Botchu, Rajesh; Allen, Patricia; Rennie, Winston J

    2013-12-01

    High ankle sprains are difficult to diagnose and account for 10% of all ankle sprains. A high index of suspicion is essential for diagnosis. High ankle sprains are managed symptomatically, with prolonged rehabilitation. The posterior inferior tibiofibular ligament is the strongest syndesmotic ligament; isolated injury of it is rare. We present 3 cases of isolated posterior high ankle sprain and discuss the relevant anatomy, mechanism of injury, and management. PMID:24366808

  17. Computational modelling of mobile bearing TKA anterior-posterior dislocation.

    PubMed

    Müller, J H; Zakaria, T; van der Merwe, W; D'Angelo, F

    2016-01-01

    Anterior-posterior stability in an unconstrained mobile-bearing total knee arthroplasty (TKA) and one with rotational constraints is compared in a computational model based on an ASTM test. Both TKA designs dislocate at loads greater than reported maximum in vivo forces. The posterior drawer forces (mean: 3027 N vs. 1817 N) needed to induce subluxation increase with a greater anterior jump distance (12 mm vs. 7 mm; refers to the vertical height of the anterior or posterior border of the tibial insert's articulating surface). The posterior jump distance for both tested TKA differed by 1.5 mm and had minimal effect on the magnitude of the anterior drawer forces at dislocation in mid-flexion (unconstrained vs. constrained: 445 N vs. 412 N). The unconstrained insert dislocated by means of spin-out whereas in the constrained TKA the femur dislocated from the bearing during posterior drawer and the bearing from the baseplate during anterior drawer. MCL function is an important consideration during ligament balancing since a ± 10% variation in MCL tension affects dislocation forces by ± 20%. The simulation platform provided the means to investigate TKA designs in terms of anterior-posterior stability as a function of knee flexion, collateral ligament function and mechanical morphology. PMID:26047039

  18. Optimizing tooth form with direct posterior composite restorations.

    PubMed

    Raghu, Ramya; Srinivasan, Raghu

    2011-10-01

    Advances in material sciences and technology have provided today's clinicians the strategies to transform the mechanistic approach of operative dentistry into a biologic philosophy. In the last three decades, composite resins have gone from being just an esthetically pleasing way of restoring Class III and Class IV cavities to become the universal material for both anterior and posterior situations as they closely mimic the natural esthetics while restoring the form of the human dentition. In order to enhance their success, clinicians have to rethink their protocol instead of applying the same restorative concepts and principles practiced with metallic restorations. Paralleling the evolution of posterior composite resin materials, cavity designs, restorative techniques and armamentarium have also developed rapidly to successfully employ composite resins in Class II situations. Most of the earlier problems with posterior composites such as poor wear resistance, polymerization shrinkage, postoperative sensitivity, predictable bonding to dentin, etc., have been overcome to a major extent. However, the clinically relevant aspect of achieving tight contacts in Class II situations has challenged clinicians the most. This paper reviews the evolution of techniques and recent developments in achieving predictable contacts with posterior composites. A Medline search was performed for articles on "direct posterior composite contacts." The keywords used were "contacts and contours of posterior composites." The reference list of each article was manually checked for additional articles of relevance. PMID:22144797

  19. Reversible collisionless magnetic reconnection

    SciTech Connect

    Ishizawa, A.; Watanabe, T.-H.

    2013-10-15

    Reversible magnetic reconnection is demonstrated for the first time by means of gyrokinetic numerical simulations of a collisionless magnetized plasma. Growth of a current-driven instability in a sheared magnetic field is accompanied by magnetic reconnection due to electron inertia effects. Following the instability growth, the collisionless reconnection is accelerated with development of a cross-shaped structure of current density, and then all field lines are reconnected. The fully reconnected state is followed by the secondary reconnection resulting in a weakly turbulent state. A time-reversed simulation starting from the turbulent state manifests that the collisionless reconnection process proceeds inversely leading to the initial state. During the reversed reconnection, the kinetic energy is reconverted into the original magnetic field energy. In order to understand the stability of reversed process, an external perturbation is added to the fully reconnected state, and it is found that the accelerated reconnection is reversible when the deviation of the E × B streamlines due to the perturbation is comparable with or smaller than a current layer width.

  20. Recovery of Third Nerve Palsy after Endovascular Packing of Internal Carotid-Posterior Communicating Artery Aneurysms

    PubMed Central

    Mavilio, N.; Pisani, R.; Rivano, C.; Testa, V.; Spaziante, R.; Rosa, M.

    2000-01-01

    Summary Endovascular packing of intracranial aneurysm with preservation of the parent vessel has become in many cases a valid alternative to surgical clipping. Regression of oculomotor disorders after clipping of internal carotid-posterior communicating artery (ICA-PCoA) aneurysms has been well assessed. This report focuses on the reversal of third nerve palsy after endovascular packing of ICA-PCoA aneurysms. To this end, clinical appearances, neuroradiological features, and endovascular interventional procedures of six treated patient are reported and discussed in the light of the very few previous case observations found in the literature. Results indicate that endovascular packing of ICA-PCoA aneurysms may produce effective recovery of correlated third nerve dysfunction. PMID:20667199

  1. Sequential Polarity-Reversing Circuit

    NASA Technical Reports Server (NTRS)

    Labaw, Clayton C.

    1994-01-01

    Proposed circuit reverses polarity of electric power supplied to bidirectional dc motor, reversible electro-mechanical actuator, or other device operating in direction depending on polarity. Circuit reverses polarity each time power turned on, without need for additional polarity-reversing or direction signals and circuitry to process them.

  2. Infarction of the unilateral posterior horn and lateral column of the spinal cord with sparing of posterior columns: demonstration by MRI.

    PubMed Central

    Kaneki, M; Inoue, K; Shimizu, T; Mannen, T

    1994-01-01

    Infarction of the spinal cord, particularly in the distribution of the posterior spinal arteries, is rare. Twenty seven cases of posterior spinal artery syndrome have been reported. In all cases, the posterior columns were affected, and in all but two, the lesions were bilateral. Here a 49-year-old woman is reported, who was affected with lumbar cord infarction in the distribution of the posterior spinal arteries, diagnosed by MRI and clinical presentation. This case is of special interest because of sparing of the posterior columns and the unilateral nature of the lesion, even though the infarction occurred in the distribution of the posterior spinal arteries. Images PMID:8201340

  3. Interoceptive awareness changes the posterior insula functional connectivity profile.

    PubMed

    Kuehn, Esther; Mueller, Karsten; Lohmann, Gabriele; Schuetz-Bosbach, Simone

    2016-04-01

    Interoceptive awareness describes the ability to consciously perceive inner bodily signals, such as one's own heartbeat. The right anterior insula is assumed to mediate this ability. The role of the posterior insula, particularly posterior-to-anterior insula signal flows is less clear in this respect. We scanned 27 healthy people with either high or low interoceptive awareness using 3T fMRI, while they either monitored their own heartbeats, or external tones, respectively. We used a combination of network centrality and bivariate connectivity analyses to characterize changes in cortical signal flows between the posterior insula and the anterior insula during interoceptive awareness or exteroceptive awareness, respectively. We show that heartbeat monitoring was accompanied by reduced network centrality of the right posterior insula, and decreased functional connectivity strengths between the right posterior insula and the right mid and anterior insula. In addition, decreased signal flows between the right posterior insula and the bilateral anterior cingulate cortices, and the bilateral orbitofrontal cortices were observed during interoceptive awareness. Functional connectivity changes were only shown by people with high interoceptive awareness, and occurred specifically within the low-frequency range (i.e., <0.1 Hz). Both groups did not differ in their functional connectivity profiles during rest. Our results show for the first time that interoceptive awareness changes intra-insula signal flows in the low-frequency range. We speculate that the selective inhibition of slow signal progression along the posterior-to-anterior insula pathway during interoceptive awareness allows the salient and noiseless detection of one's own heartbeat. PMID:25613901

  4. Correction of dental Class III with posterior open bite by simple biomechanics using an anterior C-tube miniplate

    PubMed Central

    Ahn, Hyo-Won; Chung, Kyu-Rhim; Kang, Suk-Man; Lin, Lu; Nelson, Gerald

    2012-01-01

    In the correction of dental Class III molar relationship in skeletal Class II patients, uprighting of the mandibular posterior segments without opening the mandible is an important treatment objective. In the case reported herein, a C-tube miniplate fixed to the lower labial symphysis and connected with a nickel-titanium reverse-curved archwire provided effective uprighting of the lower molars, without the need of orthodontic appliances on the mandibular anteriors. Using this approach, an appropriate magnitude of force is exerted on the molars while avoiding any negative effect on the mandibular anteriors. PMID:23173121

  5. Time reversal communication system

    DOEpatents

    Candy, James V.; Meyer, Alan W.

    2008-12-02

    A system of transmitting a signal through a channel medium comprises digitizing the signal, time-reversing the digitized signal, and transmitting the signal through the channel medium. The channel medium may be air, earth, water, tissue, metal, and/or non-metal.

  6. Justice and Reverse Discrimination

    ERIC Educational Resources Information Center

    Strike, Kenneth A.

    1976-01-01

    Although this article does not necessarily recommend policies of reverse discrimination, arguments indicating that such policies are not contradictory to accepted concepts of justice are presented. The necessity of dispersing any consequent injury to society as a whole rather than to individuals is stressed. (RW)

  7. Reversing Discrimination: A Perspective

    ERIC Educational Resources Information Center

    Pati, Gopal; Reilly, Charles W.

    1977-01-01

    Examines the debate over affirmative action and reverse discrimination, and discusses how and why the present dilemma has developed. Suggests that organizations can best address the problem through an honest, in-depth analysis of their organizational structure and management practices. (JG)

  8. Andexanet: Effectively Reversing Anticoagulation.

    PubMed

    Lippi, Giuseppe; Sanchis-Gomar, Fabian; Favaloro, Emmanuel J

    2016-06-01

    Despite direct oral anticoagulants becoming a mainstay of anticoagulant therapy, the effective, timely, and safe reversal of their anticoagulant effect remains challenging. Emerging evidence attests that andexanet, a recombinant and inactive variant of native factor X (FXa), competitively inhibits and counteracts the anticoagulant effect of many inhibitors of native activated FXa. PMID:27048885

  9. Reversible Ising dynamics

    SciTech Connect

    Creutz, M.

    1985-01-01

    The author discusses a reversible deterministic dynamics for Ising spins. The algorithm is a variation of microcanonical Monte Carlo techniques and is easily implemented with simple bit manipulation. This provides fast programs to study non-equilibrium phenomena such as heat flow.

  10. Reverse Coherent Information

    NASA Astrophysics Data System (ADS)

    García-Patrón, Raúl; Pirandola, Stefano; Lloyd, Seth; Shapiro, Jeffrey H.

    2009-05-01

    In this Letter we define a family of entanglement distribution protocols assisted by feedback classical communication that gives an operational interpretation to reverse coherent information, i.e., the symmetric counterpart of the well-known coherent information. This leads to the definition of a new entanglement distribution capacity that exceeds the unassisted capacity for some interesting channels.

  11. Reverse Coherent Information

    NASA Astrophysics Data System (ADS)

    García-Patrón, Raúl; Pirandola, Stefano; Lloyd, Seth; Shapiro, Jeffrey H.

    2009-04-01

    We define a family of entanglement distribution protocols assisted by classical feedback communication that gives an operational interpretation to reverse coherent information, i.e., the symmetric counterpart of the well-known coherent information. This protocol family leads to the definition of a new entanglement distribution capacity that exceeds the unassisted entanglement distribution capacity for some interesting channels.

  12. Injuries to the posterior cruciate ligament of the knee.

    PubMed

    Kannus, P; Bergfeld, J; Järvinen, M; Johnson, R J; Pope, M; Renström, P; Yasuda, K

    1991-08-01

    The posterior cruciate ligament (PCL) is the strongest ligament about the knee and is approximately twice as strong as the anterior cruciate ligament. Its main function is to prevent the posterior dislocation of the tibia in relation to the femur, providing 95% of the strength to resist the tibial posterior displacement. Along with the anterior cruciate ligament (ACL) the PCL controls the passive 'screw home' mechanism of the knee in terminal knee extension. It also provides mechanical support for the collateral ligaments during valgus or varus stress of the knee. PCL ruptures are uncommon apparently due to its strong fibre structure. The most frequent injury mechanism in isolated PCL tears is a direct blow on the anterior tibia with the knee flexed thus driving the tibia posteriorly. Automobile accidents (in which the knee hits the dashboard) and soccer injuries (in which an athlete receives a blow to the anterior surface of the tibia during knee flexion) characteristically produce this type of injury. In other PCL injury mechanisms (hyperextension, hyperflexion or rotational injuries with associated valgum/varum stress), other knee structures are also often damaged. The most characteristic diagnostic finding in a knee with a PCL rupture is the 'posterior sag sign' meaning the apparent disappearance of the tibial tubercle in lateral inspection when the knee is flexed 90 degrees. This is due to gravity-assisted posterior displacement of the tibia in relation to the femur. A positive posterior drawer test performed at 90 degrees of flexion and a knee hyperextension sign are sensitive but nonspecific tests. False negative findings are frequent, especially in acute cases. If necessary, the clinical diagnosis of the PCL tear can be verified by magnetic resonance imaging, examination under anaesthesia, arthroscopy, or a combination of these modalities. If a PCL avulsion fragment has been dislocated, surgical treatment is recommended. In isolated, complete midsubstance

  13. A Simple Approach to Specimen Retrieval via Posterior Colpotomy Incision

    PubMed Central

    Menderes, Gulden; Tower, Amanda M.; Silasi, Dan-Arin; Azodi, Masoud

    2015-01-01

    Introduction: Posterior colpotomy incision for specimen retrieval is infrequently used in gynecologic laparoscopic surgery unless a concomitant hysterectomy is performed. We aim to describe a simple and unique technique for creating the colpotomy incision and to describe intraoperative and postoperative outcomes. Methods: Fifty patients underwent adnexal specimen retrieval through a posterior colpotomy incision. After devascularization and detachment of the adnexal specimen, the posterior cul-de-sac was visualized. The colpotomy incision was created by introducing a 12- or 15-mm laparoscopic trocar through the vagina into the posterior vaginal fornix under direct visualization. Specimens were placed into laparoscopic bags and removed through the vagina. The colpotomy incision was closed vaginally. Charts were reviewed for intraoperative and postoperative outcomes. Results: Twenty-nine women underwent adnexal surgery for an adnexal mass, 14 women underwent surgery for pelvic pain, and 7 women underwent adnexal surgery for primary prevention of malignancy. The specimens removed ranged in size from 2 to 16 cm (mean 5.7). The mean time patients were under anesthesia was 103 minutes (SD 57.3). There were no operative complications related to the colpotomy incision and no cases of postoperative vaginal cellulitis or pelvic infection were reported. Only 1 woman with a prior vaginal delivery reported dyspareunia postoperatively. Conclusion: This simple technique for posterior colpotomy incision can easily be added to the gynecologic surgeon's armamentarium and can be safely used for most women. PMID:25901107

  14. Instrumented Posterior Lumbar Interbody Fusion in Adult Spondylolisthesis

    PubMed Central

    Yu, Ching-Hsiao; Wang, Chen-Ti

    2008-01-01

    It is unclear whether using artificial cages increases fusion rates compared with use of bone chips alone in posterior lumbar interbody fusion for patients with lumbar spondylolisthesis. We hypothesized artificial cages for posterior lumbar interbody fusion would provide better clinical and radiographic outcomes than bone chips alone. We assumed solid fusion would provide good clinical outcomes. We clinically and radiographically followed 34 patients with spondylolisthesis having posterior lumbar interbody fusion with mixed autogenous and allogeneic bone chips alone and 42 patients having posterior lumbar interbody fusion with implantation of artificial cages packed with morselized bone graft. Patients with the artificial cage had better functional improvement in the Oswestry disability index than those with bone chips alone, whereas pain score, patient satisfaction, and fusion rate were similar in the two groups. Postoperative disc height ratio, slip ratio, and segmental lordosis all decreased at final followup in the patients with bone chips alone but remained unchanged in the artificial cage group. The functional outcome correlated with radiographic fusion status. We conclude artificial cages provide better functional outcomes and radiographic improvement than bone chips alone in posterior lumbar interbody fusion for lumbar spondylolisthesis, although both techniques achieved comparable fusion rates. Level of Evidence: Level III, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence. PMID:18846411

  15. Fetoscopic transuterine release of posterior urethral valves: a new technique.

    PubMed

    Clifton, Matthew S; Harrison, Michael R; Ball, Robert; Lee, Hanmin

    2008-01-01

    Fetal urinary tract obstruction with oligohydramnios produces pulmonary hypoplasia and renal dysplasia. Decompression of the obstructed urinary tract may restore amniotic fluid and allow lung growth, but transabdominal catheter shunt decompression is often inadequate and does not allow for cycling of the bladder, while open procedures cause significant maternal morbidity. Disruption of the anatomic obstruction, usually posterior urethral valves in a male fetus, would be ideal but has proven technically difficult. Here we describe a new technique of percutaneous fetal cystoscopy and disruption of posterior urethral valves, and the case report of our first application of this technique. We pre-sent a case of a 17-week male fetus with posterior urethral valves which underwent fetal cystoscopy for mechanical disruption of posterior urethral valves. This minimally invasive approach to disruption of posterior urethral valves in a fetus is a novel method for decompressing the urinary tract. The technique offers a minimal degree of maternal morbidity and, if instituted early enough, can restore amniotic fluid volume, avert fatal pulmonary hypoplasia and may preserve renal function. PMID:18033963

  16. Flexor Digitorum Accessorius Longus: Importance of Posterior Ankle Endoscopy

    PubMed Central

    Batista, Jorge Pablo; del Vecchio, Jorge Javier; Golanó, Pau; Vega, Jordi

    2015-01-01

    Endoscopy for the posterior region of the ankle through two portals is becoming more widespread for the treatment of a large number of conditions which used to be treated with open surgery years ago. The tendon of the flexor hallucis longus (FHL) travels along an osteofibrous tunnel between the posterolateral and posteromedial tubercles of the talus. Chronic inflammation of this tendon may lead to painful stenosing tenosynovitis. The aim of this report is to describe two cases depicting an accessory tendon which is an anatomical variation of the flexor hallucis longus in patients with posterior friction syndrome due to posterior ankle impingement and associated with a posteromedial osteochondral lesion of the talus. The anatomical variation (FDAL) described was a finding during an endoscopy of the posterior region of the ankle, and we have spared it by sectioning the superior flexor retinaculum only. The accessory flexor digitorum longus is an anatomical variation and should be taken into account when performing an arthroscopy of the posterior region of the ankle. We recommend this treatment on this type of injury although we admit this does not make a definite conclusion. PMID:26060592

  17. Quantification of Posterior Globe Flattening: Methodology Development and Validationc

    NASA Technical Reports Server (NTRS)

    Lumpkins, S. B.; Garcia, K. M.; Sargsyan, A. E.; Hamilton, D. R.; Berggren, M. D.; Antonsen, E.; Ebert, D.

    2011-01-01

    Microgravity exposure affects visual acuity in a subset of astronauts, and mechanisms may include structural changes in the posterior globe and orbit. Particularly, posterior globe flattening has been implicated in several astronauts. This phenomenon is known to affect some terrestrial patient populations, and has been shown to be associated with intracranial hypertension. It is commonly assessed by magnetic resonance imaging (MRI), computed tomography (CT), or B-mode ultrasound (US), without consistent objective criteria. NASA uses a semi-quantitative scale of 0-3 as part of eye/orbit MRI and US analysis for occupational monitoring purposes. The goal of this study was to initiate development of an objective quantification methodology for posterior globe flattening.

  18. Regression of posterior uveal melanomas following cobalt-60 plaque radiotherapy

    SciTech Connect

    Cruess, A.F.; Augsburger, J.J.; Shields, J.A.; Brady, L.W.; Markoe, A.M.; Day, J.L.

    1984-12-01

    A method has been devised for evaluating the rate and extent of regression of the first 100 consecutive patients with a posterior uveal melanoma that had been managed by Cobalt-60 plaque radiotherapy at Wills Eye Hospital. It was found that the average posterior uveal melanoma in the series did not regress rapidly to a flat, depigmented scar but shrank slowly and persisted as a residual mass approximately 50% of the thickness of the original tumor at 54 months following Cobalt-60 plaque radiotherapy. The authors also found that the rate and extent of regression of the tumors in patients who subsequently developed metastatic melanoma were not appreciably different from the rate and extent of regression of the tumors in patients who remained well systemically. These observations indicate that the rate and extent of regression of posterior uveal melanomas following Cobalt-60 plaque radiotherapy are poor indicators of the prognosis of the affected patients for subsequent development of clinical metastatic disease.

  19. Arthroscopic Repair of a Posterior Bony Bankart Lesion

    PubMed Central

    Poehling-Monaghan, Kirsten L.; Krych, Aaron J.; Dahm, Diane L.

    2015-01-01

    Posterior bony defects of the glenoid rim, particularly those associated with instability, are often a frustrating challenge for arthroscopists because of the defects' inaccessibility from standard portals. This challenge is enhanced when the lesion is chronic and fibrous malunion of the fragment makes mobilization difficult. We present our technique for arthroscopic repair of the relatively uncommon chronic posterior bony Bankart lesion. By use of lateral positioning and a standard anterior viewing portal and posterior working portal, as well as a strategically placed posterolateral accessory portal, the lesion is first freed from its malreduced position and ultimately repaired using suture anchor fixation of the bony fragment along with its associated labrum directly to the remaining glenoid rim. This technique, facilitated by precise portal placement, results in satisfactory fragment reduction, appropriate capsular tension, and restoration of anatomy. PMID:26870644

  20. Quantification of Posterior Globe Flattening: Methodology Development and Validation

    NASA Technical Reports Server (NTRS)

    Lumpkins, Sarah B.; Garcia, Kathleen M.; Sargsyan, Ashot E.; Hamilton, Douglas R.; Berggren, Michael D.; Ebert, Douglas

    2012-01-01

    Microgravity exposure affects visual acuity in a subset of astronauts and mechanisms may include structural changes in the posterior globe and orbit. Particularly, posterior globe flattening has been implicated in the eyes of several astronauts. This phenomenon is known to affect some terrestrial patient populations and has been shown to be associated with intracranial hypertension. It is commonly assessed by magnetic resonance imaging (MRI), computed tomography (CT) or B-mode Ultrasound (US), without consistent objective criteria. NASA uses a semiquantitative scale of 0-3 as part of eye/orbit MRI and US analysis for occupational monitoring purposes. The goal of this study was ot initiate development of an objective quantification methodology to monitor small changes in posterior globe flattening.

  1. Ganglion cyst of the posterior cruciate ligament in a child.

    PubMed

    Hameed, Shamsi Abdul; Sujir, Premjit; Naik, Monappa A; Rao, Sharath K

    2012-04-01

    Ganglion cysts are more commonly associated with the anterior cruciate ligament than the posterior cruciate ligament (PCL). A literature review showed that all reported cases of ganglion cysts to date involved adults. We report a rare case of ganglion cyst in the PCL of a four-year-old boy, and discuss its aetiology, clinical presentation, imaging features and management. Ganglion cysts of the PCL may be confused with meniscal cysts arising from tears of the posterior horn of the medial meniscus on magnetic resonance (MR) imaging. Hence, the posterior horn of the medial meniscus has to be carefully evaluated to rule out a tear. MR imaging is the method of choice to confirm diagnosis, and arthroscopic resection is a safe treatment modality even in children. PMID:22511069

  2. Rotational stability of a posterior stabilized total knee arthroplasty.

    PubMed

    Whiteside, L A; Amador, D D

    1989-05-01

    The effect of the posterior stabilizing mechanism on rotational stability in total knee arthroplasty (TKA) was investigated in six cadaver knees using a special knee-testing device. The device evaluated varus-valgus, rotational, and anteroposterior (AP) stability in the normal knee compared to a posterior stabilized TKA with either a rotationally constrained or an unconstrained articular surface. None of the stability parameters was significantly different from normal in either configuration of the tibial surface, but the constrained surface did decrease rotational deflection compared to the rotationally unconstrained surfaces. These findings show that rotational constraint in a posterior stabilized TKA is not necessary to achieve rotational stability as long as varus-valgus stability is achieved by appropriately tensioning the collateral ligaments. PMID:2706852

  3. 49 CFR 230.89 - Reverse gear.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Reversing Gear § 230.89 Reverse gear. (a) General provisions. Reverse gear, reverse levers, and quadrants shall be maintained in a safe and suitable condition for service. Reverse lever latch shall be...

  4. 49 CFR 230.89 - Reverse gear.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Reversing Gear § 230.89 Reverse gear. (a) General provisions. Reverse gear, reverse levers, and quadrants shall be maintained in a safe and suitable condition for service. Reverse lever latch shall be...

  5. 49 CFR 230.89 - Reverse gear.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Reversing Gear § 230.89 Reverse gear. (a) General provisions. Reverse gear, reverse levers, and quadrants shall be maintained in a safe and suitable condition for service. Reverse lever latch shall be...

  6. 49 CFR 230.89 - Reverse gear.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Reversing Gear § 230.89 Reverse gear. (a) General provisions. Reverse gear, reverse levers, and quadrants shall be maintained in a safe and suitable condition for service. Reverse lever latch shall be...

  7. The posterior bone block procedure in posterior shoulder instability: a long-term follow-up study.

    PubMed

    Meuffels, D E; Schuit, H; van Biezen, F C; Reijman, M; Verhaar, J A N

    2010-05-01

    We present the long-term outcome, at a median of 18 years (12.8 to 23.5) of open posterior bone block stabilisation for recurrent posterior instability of the shoulder in a heterogenous group of 11 patients previously reported on in 2001 at a median follow-up of six years. We found that five (45%) would not have chosen the operation again, and that four (36%) had further posterior dislocation. Clinical outcome was significantly worse after 18 years than after six years of follow-up (median Rowe score of 60 versus 90 (p = 0.027)). The median Western Ontario Shoulder Index was 60% (37% to 100%) at 18 years' follow-up, which is a moderate score. At the time of surgery four (36%) had glenohumeral radiological osteoarthritis, which was present in all after 18 years. This study showed poor long-term results of the posterior bone block procedure for posterior instability and a high rate of glenohumeral osteoarthritis although three patients with post-traumatic instability were pleased with the result of their operations. PMID:20436001

  8. Bilambdoid and posterior sagittal synostosis: the Mercedes Benz syndrome.

    PubMed

    Moore, M H; Abbott, A H; Netherway, D J; Menard, R; Hanieh, A

    1998-09-01

    A consistent pattern of craniosynostosis in the sagittal and bilateral lambdoid sutures is described in three patients. The external cranial ridging associated with fusion of these sutures produces a characteristic triradiate, or "Mercedes Benz," appearance to the posterior skull. Locally marked growth restriction is evident in the posterior fossa with compensatory secondary expansion of the anterior fossa manifesting a degree of frontal bossing which mimics bicoronal synostosis. Although this appearance could lead to inadvertent surgery in the frontal region, attention to the occipital region with wide early suture excision and vault shaping is indicated. PMID:9780908

  9. Surgical treatment of posterior nutcracker syndrome presented with hyperaldosteronism.

    PubMed

    Deser, Serkan Burc; Onem, Kadir; Demirag, Mustafa Kemal; Buyukalpelli, Recep

    2016-05-01

    Posterior nutcracker syndrome is caused by the compression of left renal vein between the abdominal aorta and the vertebral body. Most seen symptoms are haematuria, left flank pain, abdominal pain and varicocele. The nutcracker syndrome may lead to left renal vein thrombosis due to blood congestion within compression of the vessel. Both endovascular and open surgical interventions can relieve symptoms; however, traditional surgical repair is still considered as the gold standard. Here, we present the surgical treatment of a 36-year old female with complaints of hypertension, hyperaldosteronism and diagnosed with posterior nutcracker syndrome. PMID:26892192

  10. Superior labrum anterior to posterior tears in throwing athletes.

    PubMed

    Lintner, David M

    2013-01-01

    Superior labrum anterior to posterior (SLAP) tears and partial undersurface tears of the rotator cuff are common in experienced throwers, may be adaptive, and are only occasionally symptomatic. Pain in the shoulder of a throwing athlete with an MRI-documented SLAP tear or partial undersurface tear of the rotator cuff can be managed nonsurgically, with attention to posterior capsular contracture, scapular dyskinesia, and rotator cuff strength. The results of the surgical repair of SLAP lesions in the throwing athlete, with or without rotator cuff repair, are inferior to those of nonsurgical treatment. The cause of pain in the throwing athlete must be accurately diagnosed without reliance on MRI findings. PMID:23395053

  11. Reverse genetics of mononegavirales.

    PubMed

    Conzelmann, K K

    2004-01-01

    "Reverse genetics" or de novo synthesis of nonsegmented negative-sense RNA viruses (Mononegavirales) from cloned cDNA has become a reliable technique to study this group of medically important viruses. Since the first generation of a negative-sense RNA virus entirely from cDNA in 1994, reverse genetics systems have been established for members of most genera of the Rhabdo-, Paramyxo-, and Filoviridae families. These systems are based on intracellular transcription of viral full-length RNAs and simultaneous expression of viral proteins required to form the typical viral ribonucleoprotein complex (RNP). These systems are powerful tools to study all aspects of the virus life cycle as well as the roles of virus proteins in virus-host interplay and pathogenicity. In addition, recombinant viruses can be designed to have specific properties that make them attractive as biotechnological tools and live vaccines. PMID:15298166

  12. Gridded electron reversal ionizer

    NASA Technical Reports Server (NTRS)

    Chutjian, Ara (Inventor)

    1993-01-01

    A gridded electron reversal ionizer forms a three dimensional cloud of zero or near-zero energy electrons in a cavity within a filament structure surrounding a central electrode having holes through which the sample gas, at reduced pressure, enters an elongated reversal volume. The resultant negative ion stream is applied to a mass analyzer. The reduced electron and ion space-charge limitations of this configuration enhances detection sensitivity for material to be detected by electron attachment, such as narcotic and explosive vapors. Positive ions may be generated by generating electrons having a higher energy, sufficient to ionize the target gas and pulsing the grid negative to stop the electron flow and pulsing the extraction aperture positive to draw out the positive ions.

  13. Reversible cerebral vasoconstriction syndrome: rare or underrecognized in children?

    PubMed

    Probert, Rebecca; Saunders, Dawn E; Ganesan, Vijeya

    2013-04-01

    Reversible cerebral vasoconstriction syndrome (RCVS) is a clinicoradiological diagnosis comprising 'thunderclap' headaches and reversible segmental vasoconstriction of cerebral arteries, occasionally complicated by ischaemic or haemorrhagic stroke. We report a case of RCVS in a 13-year-old male with severe thunderclap headaches and no focal neurological signs. Brain imaging showed multiple posterior circulation infarcts; cerebral computed tomography, magnetic resonance imaging, and catheter angiography showed multifocal irregularity and narrowing, but in different arterial segments. Laboratory studies did not support a diagnosis of vasculitis. Symptoms resolved over 3 weeks; magnetic resonance angiography 3 months later was normal and remained so after 2 years. We highlight the typical clinical features of RCVS in this case and suggest that the diagnosis should be considered in children with thunderclap headaches or stroke syndromes where headache is a prominent feature, especially if cerebrovascular imaging studies appear to be evolving or discrepant. PMID:23066702

  14. Field reversed ion rings

    SciTech Connect

    Sudan, R.N.; Omelchenko, Y.A.

    1995-09-01

    In typical field-reversed ion ring experiments, an intense annular ion beam is injected across a plasma-filled magnetic cusp region into a neutral gas immersed in a ramped solenoidal magnetic field. Assuming the characteristic ionization time is much shorter than the long ({ital t}{approx_gt}2{pi}/{Omega}{sub {ital i}}) beam evolution time scale, we investigate the formation of an ion ring in the background plasma followed by field reversal, using a 21/2-D hybrid, PIC code FIRE, in which the beam and background ions are treated as particles and the electrons as a massless fluid. We show that beam bunching and trapping occurs downstream in a ramped magnetic field for an appropriate set of experimental parameters. We find that a compact ion ring is formed and a large field reversal {zeta}={delta}{ital B}/{ital B}{approx_gt}1 on axis develops. We also observe significant deceleration of the ring on reflection due to the transfer of its axial momentum to the background ions, which creates favorable trapping conditions. {copyright} {ital 1995 American Institute of Physics.}

  15. Tevatron reverse injection

    SciTech Connect

    Saritepe, S.; Annala, G.

    1993-06-25

    In the new injection scenario antiprotons are injected onto a helical orbit in the Tevatron in order to avoid the detrimental effects of the beam-beam interaction at 150 GeV. The new scenario required changes in the tuning procedure. Antiprotons are too precious to be used for tuning, therefore the antiproton injection line has to be tuned with protons by reverse injecting them from the Tevatron into the Main Pang (MR). Previously, the reverse injection was performed in one supercycle. One batch of uncoalesced bunches was injected into the Tevatron and ejected after 40 seconds. Then the orbit closure was performed in the MR. In the new scheme the lambertson magnets have to be moved and separator polarities have to be switched, activities that cannot be completed in one supercycle. Therefore, the reverse injection sequence was changed. This involved the redefinition of TVBS dock event $D8 as MRBS $D8 thus marking it possible to inject 6 proton batches and eject them one at a time on command, performing orbit closure each time in the MR.

  16. Reversible DNA compaction.

    PubMed

    González-Pérez, Alfredo

    2014-01-01

    In this review we summarize and discuss the different methods we can use to achieve reversible DNA compaction in vitro. Reversible DNA compaction is a natural process that occurs in living cells and viruses. As a result these process long sequences of DNA can be concentrated in a small volume (compacted) to be decompacted only when the information carried by the DNA is needed. In the current work we review the main artificial compacting agents looking at their suitability for decompaction. The different approaches used for decompaction are strongly influenced by the nature of the compacting agent that determines the mechanism of compaction. We focus our discussion on two main artificial compacting agents: multivalent cations and cationic surfactants that are the best known compacting agents. The reversibility of the process can be achieved by adding chemicals like divalent cations, alcohols, anionic surfactants, cyclodextrins or by changing the chemical nature of the compacting agents via pH modifications, light induced conformation changes or by redox-reactions. We stress the relevance of electrostatic interactions and self-assembly as a main approach in order to tune up the DNA conformation in order to create an on-off switch allowing a transition between coil and compact states. The recent advances to control DNA conformation in vitro, by means of molecular self-assembly, result in a better understanding of the fundamental aspects involved in the DNA behavior in vivo and serve of invaluable inspiration for the development of potential biomedical applications. PMID:24444152

  17. Posterior Trans-Dural Repair of Iatrogenic Spinal Cord Herniation after Resection of Ossification of Posterior Longitudinal Ligament

    PubMed Central

    Kim, Hong-Ki; Kim, Ki-Jeong; Jahng, Tae-Ahn; Kim, Hyun-Jib

    2016-01-01

    Iatrogenic spinal cord herniation is a rare complication following spinal surgery. We introduce a posterior trans-dural repair technique used in a case of thoracic spinal cord herniation through a ventral dural defect following resection of ossification of the posterior longitudinal ligament (OPLL) in the cervicothoracic spine. A 51-year-old female was suffering from paraplegia after laminectomy alone for cervicothoracic OPLL. Magnetic resonance imaging revealed a severely compressed spinal cord with pseudomeningocele identified postoperatively. Cerebrospinal fluid leak and iatrogenic spinal cord herniation persisted despite several operations with duroplasty and sealing agent. Finally, the problems were treated by repair of the ventral dural defect with posterior trans-dural duroplasty. Several months after surgery, the patient could walk independently. This surgical technique can be applied to treat ventral dural defect and spinal cord herniation. PMID:27114779

  18. Postoperative paralysis following posterior decompression with instrumented fusion for thoracic myelopathy caused by ossification of the posterior longitudinal ligament.

    PubMed

    Yamazaki, Masashi; Okawa, Akihiko; Mannoji, Chikato; Fujiyoshi, Takayuki; Furuya, Takeo; Koda, Masao

    2011-02-01

    A 60-year-old man presented with thoracic myelopathy due to ossification of the posterior longitudinal ligament (OPLL). His spinal cord was severely impinged anteriorly by a beak-type OPLL and posteriorly by ossification of the ligamentum flavum at T4/5. He underwent surgical posterior decompression with instrumented fusion (PDF). Immediately after surgery, he developed a Brown-Séquard-type paralysis, which spontaneously resolved without requiring the addition of OPLL extirpation. This example highlights that the risk of postoperative neurological deterioration cannot be eliminated even when PDF is selected as the surgical procedure for thoracic OPLL, especially in instances in which the spinal cord is severely compressed. PMID:21030260

  19. Lesion Analysis of Cortical Regions Associated with the Comprehension of Nonreversible and Reversible Yes/No Questions

    ERIC Educational Resources Information Center

    Race, David S.; Ochfeld, Elisa; Leigh, Richard; Hillis, Argye E.

    2012-01-01

    We investigated the association between yes/no sentence comprehension and dysfunction in anterior and posterior left-hemisphere cortical regions in acute stroke patients. More specifically, we manipulated whether questions were Nonreversible (e.g., Are limes sour?) or Reversible (e.g., Is a horse larger than a dog?) to investigate the regions…

  20. [Reverse Chaddock sign].

    PubMed

    Tashiro, Kunio

    2011-08-01

    It is widely accepted that the Babinski reflex is the most well-known and important pathological reflex in clinical neurology. Among many other pathological reflexes that elicit an upgoing great toe, such as Chaddock, Oppenheim, Gordon, Schaefer, and Stransky, only the Chaddock reflex is said to be as sensitive as the Babinski reflex. The optimal receptive fields of the Babinski and Chaddock reflexes are the lateral plantar surface and the external inframalleolar area of the dorsum, respectively. It has been said that the Babinski reflex, obtained by stroking the sole, is by far the best and most reliable method of eliciting an upgoing great toe. However, the Chaddock reflex, the external malleolar sign, is also considered sensitive and reliable according to the literature and everyday neurological practice. The major problems in eliciting the Babinski reflex by stroking the lateral part of the sole are false positive or negative responses due to foot withdrawal, tonic foot response, or some equivocal movements. On the other hand, according to my clinical experience, the external inframalleolar area, which is the receptive field of the Chaddock reflex, is definitely suitable for eliciting the upgoing great toe. In fact, the newly proposed method to stimulate the dorsum of the foot from the medial to the lateral side, which I term the "reversed Chaddock method," is equally sensitive to demonstrate pyramidal tract involvement. With the "reversed Chaddock method", the receptive field of the Chaddock reflex may be postulated to be in the territory of the sural nerve, which could be supported by the better response obtained on stimulation of the postero-lateral calf than the anterior shin. With regard to the receptive fields of the Babinski and Chaddock reflexes, the first sacral dermatome (S1) is also considered a reflexogenous zone, but since the dermatome shows marked overlapping, the zones vary among individuals. As upgoing toe responses are consistently observed in

  1. Clinical and Radiological Results of Microsurgical Posterior Lumbar Interbody Fusion and Decompression without Posterior Instrumentation for Lateral Recess Stenosis

    PubMed Central

    Şişman, Lokman; Türkmen, Faik; Efe, Duran; Pekince, Oğuzhan; Göncü, Recep Gani; Sever, Cem

    2015-01-01

    Study Design A single-center, retrospective patient review of clinical and radiological outcomes of microsurgical posterior lumbar interbody fusion and decompression, without posterior instrumentation, for the treatment of lateral recess stenosis. Purpose This study documented the clinical and radiological results of microsurgical posterior lumbar interbody fusion and decompression of the lateral recess using interbody cages without posterior instrumentation for the treatment of lateral recess stenosis. Overview of Literature Although microsurgery has some advantages, various complications have been reported following microsurgical decompression, including cage migration, pseudoarthrosis, neurologic deficits, and persistent pain. Methods A total of 34 patients (13 men, 21 women), with a mean age of 56.65±9.1 years (range, 40-77 years) confirmed spinal stability, and preoperative radiological findings of lateral recess stenosis, were included in the study. Interbody polyetheretherketone cages and auto grafts were used in all patients. Posterior instrumentation was not used because of limited resection of the posterior lumbar structures. Preoperative and postoperative radiographs, computed tomography scans, and magnetic resonance imaging were assessed and compared to images taken at the final follow-up. Functional recovery was also evaluated according to the Macnab criteria at the final follow-up. Results The average follow-up time was 35.05±8.65 months (range, 24-46 months). The clinical results, operative time, intraoperative blood loss, and duration of hospital stay were similar to previously published results; the fusion rate (85.2%) was decreased and the migration rate (5.8%) was increased, compared with prior reports. Conclusions Although microsurgery has some advantages, migration and pseudoarthrosis remain challenges to achieving adequate lumbar interbody fusion. PMID:26435789

  2. Failure of the Pipeline Embolization Device in Posterior Communicating Artery Aneurysms Associated with a Fetal Posterior Cerebral Artery

    PubMed Central

    Zanaty, Mario; Chalouhi, Nohra; Starke, Robert M.; Jabbour, Pascal; Ryken, Katherine O.; Bulsara, Ketan R.; Hasan, David

    2016-01-01

    The pipeline embolization device has emerged as an important endovascular option. This is in part due to safety, efficacy, and possibly the ability to shorten the operative time considerably. With this new technology, some limitations are emerging as experience accumulates. We report three cases of posterior communicating (PCOM) artery aneurysms associated with fetal posterior cerebral artery where pipeline embolization was unsuccessful in obliterating the aneurysms. PCOM artery aneurysms associated with a fetal PCA should be managed either by microsurgical clipping or coiling when feasible. PMID:27069709

  3. Suture Bridge Fixation Technique for Posterior Cruciate Ligament Avulsion Fracture

    PubMed Central

    Lee, Kwang Won; Lee, Gyu Sang; Choy, Won Sik

    2015-01-01

    We presented a surgical technique including a suture bridge technique with relatively small incision for the reduction and fixation of posterior ligament avulsion fractures. A suture anchor was used to hold the avulsed fragment and a knotless anchor was used to continuously compress the bony fragment into the fracture site, thereby maintaining reduction during healing. PMID:26640635

  4. FEMORAL INSERTION OF THE POSTERIOR CRUCIATE LIGAMENT: AN ANATOMICAL STUDY

    PubMed Central

    de Paula Leite Cury, Ricardo; Severino, Nilson Roberto; Camargo, Osmar Pedro Arbix; Aihara, Tatsuo; Neto, Leopoldo Viana Batista; Goarayeb, Dedley Nelson

    2015-01-01

    Objective: To identify objective parameters to guide correct location of the posterior cruciate ligament (PCL) in the femur. Methods: The PCLs of 20 human cadavers were resected. The following portions were measured: distance from the most distal portion of the PCL, close to the roof, to the most anterior edge of the cartilage (AB); distance from the most proximal portion of the PCL, close to the roof, to the most anterior cartilage (AC); distance between the two parts of the ligament close to the roof (BC); distance from the distal edge in its posterior portion, to the more posterior joint edge (DE); distance from the distal edge of the ligament in its posterior portion, to the intercondylar roof (DF); and finally, the format of the ligament insertion and area of coverage on the femoral condyle. Results: The PCL has the shape of a quarter ellipse, with an average area of 153.5mm2. The mean distances found were: AB of 2.1mm, AC of 10.7mm, BC of 8.6mm DE of 12.4mm and DF of 16.8mm. Conclusions: The edge close to the roof of the anterolateral bundle is closer to the joint cartilage (2.1mm) than the posteromedial bundle is, which is 12.4mm from the edge proximal to the cartilage. These references should assist in better and more accurate positioning of femoral tunnels in PCL reconstruction. PMID:27027059

  5. Atrial natriuretic factor-like activity in rat posterior pituitary

    SciTech Connect

    Gutkowska, J.; Debinski, W.; Racz, K.; Thibault, G.; Garcia, R.; Kuchel, O.; Genest, J.; Cantin, M.

    1986-03-05

    The presence of a biologically active peptide: Atrial Natriuretic Factor (ANF) has been demonstrated in rat and human circulation and ANF is considered now as a new hormone. ANF may be involved in body fluid regulation. A very sensitive radioimmunoassay for rat ANF allowed the authors to search for immunoreactive ANF (IR-ANF) in rat posterior pituitary. Serial dilutions of homogenates of rat posterior pituitary showed a good parallelism with a reference curve in a radioimmunoassay system. The IR-ANF was extracted from rat posterior pituitary homogenates by activated Vycor glass beads. The lyophilized extract was purified by HPLC on C/sub 18/ ..mu.. Bondapak column. The HPLC yielded two IR-ANF peaks. Both isolated ANF-like material showed biological activity. The IR-ANF eluted with 33% acetonitrile, inhibited ACTH-stimulated aldosterone secretion with a similar potency as synthetic (Arg 101 - Tyr 126) ANF (0.7 x 10/sup -10/M). A much less potent ANF-like material was found in the second peak eluted with 36% acetonitrile. They conclude that ANF-like material is present in rat posterior pituitary and this suggest a possible role in ANF on AVP secretion directly in situ.

  6. Posterior Cortical Atrophy Presenting with Superior Arcuate Field Defect

    PubMed Central

    Wan, Sue Ling; Bukowska, Danuta M.; Ford, Stephen; Chen, Fred K.

    2015-01-01

    An 80-year-old female with reading difficulty presented with progressive arcuate field defect despite low intraocular pressure. Over a 5-year period, the field defect evolved into an incongruous homonymous hemianopia and the repeated neuroimaging revealed progressive posterior cortical atrophy. Further neuropsychiatric assessment demonstrated symptoms and signs consistent with Benson's syndrome. PMID:26417467

  7. Covering Your Posterior: Teaching Signaling Games Using Classroom Experiments

    ERIC Educational Resources Information Center

    Turocy, Theodore L.

    2009-01-01

    The author describes a protocol for classroom experiments for courses that introduce undergraduates to signaling games. Signaling games are conceptually difficult because, when analyzing the game, students are not naturally inclined to think in probabilistic, Bayesian terms. The experimental design explicitly presents the posterior frequencies of…

  8. Tibialis Anterior Tendon Transfer for Posterior Tibial Tendon Insufficiency.

    PubMed

    Ramanujam, Crystal L; Stapleton, John J; Zgonis, Thomas

    2016-01-01

    The Cobb procedure is useful for addressing stage 2 posterior tibial tendon dysfunction and is often accompanied by a medial displacement calcaneal osteotomy and/or lateral column lengthening. The Cobb procedure can also be combined with selected medial column arthrodesis and realignment osteotomies along with equinus correction when indicated. PMID:26590721

  9. Learning about Posterior Probability: Do Diagrams and Elaborative Interrogation Help?

    ERIC Educational Resources Information Center

    Clinton, Virginia; Alibali, Martha W.; Nathan, Mitchell J.

    2016-01-01

    To learn from a text, students must make meaningful connections among related ideas in that text. This study examined the effectiveness of two methods of improving connections--elaborative interrogation and diagrams--in written lessons about posterior probability. Undergraduate students (N = 198) read a lesson in one of three questioning…

  10. Surface characteristics of posterior composites after polishing and toothbrushing.

    PubMed

    van Dijken, J W; Ruyter, I E

    1987-10-01

    The surface characteristics of eight posterior and two anterior composite resins were studied by SEM and profilometric tracings. The materials included both chemically cured and light-cured resin systems. Two posterior materials were microfilled composites; the others were conventional or hybrid types. The anterior composites were of conventional and hybrid types. At various steps in the procedures the following polishing/brushing treatments were evaluated: 1) dry polishing with Sof-lex discs followed by brushing with toothpaste; and 2) wet polishing with diamond pastes of increasing fineness, followed by brushing with toothpaste. The base line before the polishing/brushing procedures was obtained by wet polishing on silicon-carbide paper (4000 grit). All materials could be polished to a comparable smoothness by the Sof-lex discs, but this polishing procedure was associated with the development of an amorphous surface layer. Polishing with diamond pastes gave various results, with a 20-fold difference in surface roughness values from the smoothest to the roughest material. Toothbrushing after polishing with the Sof-lex system increased the surface roughness for all materials, but to various degrees. The two microfilled and four of the conventional posterior composites showed comparable surface roughness values, whereas two remaining posterior and the two anterior materials showed two to three times higher surface roughness values after toothbrushing. PMID:3478939

  11. Bilateral posterior shoulder dislocation after electrical shock: A case report

    PubMed Central

    Ketenci, Ismail Emre; Duymus, Tahir Mutlu; Ulusoy, Ayhan; Yanik, Hakan Serhat; Mutlu, Serhat; Durakbasa, Mehmet Oguz

    2015-01-01

    Introduction Posterior dislocation of the shoulder is a rare and commonly missed injury. Unilateral dislocations occur mostly due to trauma. Bilateral posterior shoulder dislocations are even more rare and result mainly from epileptic seizures. Electrical injury is a rare cause of posterior shoulder dislocation. Injury mechanism in electrical injury is similar to epileptic seizures, where the shoulder is forced to internal rotation, flexion and adduction. Presentation of case This report presents a case of bilateral posterior shoulder dislocation after electrical shock. We were able to find a few individual case reports describing this condition. The case was acute and humeral head impression defects were minor. Our treatment in this case consisted of closed reduction under general anesthesia and applying of orthoses which kept the shoulders in abduction and external rotation. A rehabilitation program was begun after 3 weeks of immobilization. After 6 months of injury the patient has returned to work. 20 months postoperatively, at final follow-up, he was painless and capable of performing all of his daily activities. Discussion The amount of bilateral shoulder dislocations after electrical injury is not reported but is known to be very rare. The aim of this case presentation is to report an example for this rare entity, highlight the difficulties in diagnosis and review the treatment options. Conclusion Physical examination and radiographic evaluation are important for quick and accurate diagnosis. PMID:26904192

  12. Predictor variables for forward scapular posture including posterior shoulder tightness.

    PubMed

    Lee, Ji-Hyun; Cynn, Heon-seock; Yi, Chung-Hwi; Kwon, Oh-yun; Yoon, Tae-Lim

    2015-04-01

    The purpose of this study was (1) to determine the relationships between the degree of forward scapular posture and the pectoralis minor index, the strength of the serratus anterior, the thoracic spine angle, and posterior shoulder tightness, and (2) to identify predictors of forward scapular posture, including posterior shoulder tightness. The study recruited eighteen subjects with forward scapular posture and objectively measured the acromion distance, the pectoralis minor index, and the strength of the serratus anterior muscle of each participant. The amount of glenohumeral horizontal adduction and internal rotation were evaluated to measure posterior shoulder tightness. There were high intra-rater reliabilities in all measurements. The measurement results showed a statistically strong negative correlation between the degree of forward scapular posture and the pectoralis minor index. They also revealed a moderate positive correlation between the degree of forward scapular posture and the thoracic spine angle and a moderate negative relationship between the degree of forward scapular posture and the amount of the glenohumeral horizontal adduction. A multiple regression analysis indicated that a total multiple regression model explained 93% of the amount of forward scapular posture. All predictor variables, including posterior shoulder tightness, should be considered while assessing, managing, and preventing forward scapular posture. PMID:25892380

  13. Affirmative Action, or Reverse Discrimination?

    ERIC Educational Resources Information Center

    Dansby, Ike

    1996-01-01

    Determines the impact of affirmative action programs in response to charges that they are policies of reverse discrimination. Reviewing affirmative action programs submitted by Michigan State departments, researchers determined no reverse discrimination was apparent based on low numbers of reverse discrimination complaints filed by whites. (GR)

  14. Posterior approaches for symptomatic metastatic spinal cord compression.

    PubMed

    Molina, Camilo; Goodwin, C Rory; Abu-Bonsrah, Nancy; Elder, Benjamin D; De la Garza Ramos, Rafael; Sciubba, Daniel M

    2016-08-01

    Surgical interventions for spinal metastasis are commonly performed for mechanical stabilization, pain relief, preservation of neurological function, and local tumor reduction. Although multiple surgical approaches can be used for the treatment of metastatic spinal lesions, posterior approaches are commonly performed. In this study, the role of posterior surgical procedures in the treatment of spinal metastases was reviewed, including posterior laminectomy with and without instrumentation for stabilization, transpedicular corpectomy, and costotransversectomy. A review of the literature from 1980 to 2015 was performed using Medline, as was a review of the bibliographies of articles meeting preset inclusion criteria, to identify studies on the role of these posterior approaches among adults with spinal metastasis. Thirty-four articles were ultimately analyzed, including 1 randomized controlled trial, 6 prospective cohort studies, and 27 retrospective case reports and/or series. Some of the reviewed articles had Level II evidence indicating that laminectomy with stabilization can be recommended for improvement in neurological outcome and reduction of pain in selected patients. However, the use of laminectomy alone should be carefully considered. Additionally, transpedicular corpectomy and costotransversectomy can be recommended with the expectation of improving neurological outcomes and reducing pain in properly selected patients with spinal metastases. With improvements in the treatment paradigms for patients with spinal metastasis, as well as survival, surgical therapy will continue to play an important role in the management of spinal metastasis. While this review presents a window into determining the utility of posterior approaches, future prospective studies will provide essential data to better define the roles of the various options now available to surgeons in treating spinal metastases. PMID:27476835

  15. Posterior Ankle Structure Injury During Total Ankle Replacement.

    PubMed

    Reb, Christopher W; McAlister, Jeffrey E; Hyer, Christopher F; Berlet, Gregory C

    2016-01-01

    Total ankle replacement studies have focused on reporting complications that are directly observed clinically or radiographically, including wound problems, technical errors, implant loosening, subsidence, infection, bone fractures, and heterotopic ossification. However, patients can still experience unresolved pain even when these problems have been ruled out. We initiated a study to more clearly define the relative risk of injury to the anatomic structures in the posterior ankle during total ankle replacement using a third-generation implant system. Ten fresh-frozen adult cadaveric below-the-knee specimens were positioned in the intraoperative positioning frame of an approved total ankle replacement system and adjusted to achieve proper foot alignment using fluoroscopic imaging. The relationship between the tibial cutting guide pins and the posterior neurovascular and tendon structures was measured using digital calipers. High rates of posterior structural injury were found. Nearly all proximal-medial pins encountered a posteromedial neurovascular structure, most commonly the tibial nerve. The distal-medial pins mainly encountered posteromedial tendinous structures, in particular, the flexor digitorum longus tendon. The proximal lateral pins were highly likely to encounter the Achilles tendon and the sural nerve. Our results support our hypothesis that the tibial neurovascular structures are at the greatest risk when preparing for and completing the bony resection, particularly with the medial and proximal cuts. Posterior ankle soft tissue structure injuries can occur during implantation but currently with unknown frequency and undetermined significance. Further study of posterior structural injuries could result in a more informed approach to post-total ankle replacement complications and management. PMID:27291681

  16. Morphofunctional Compensation of Masseter Muscles in Unilateral Posterior Crossbite Patients

    PubMed Central

    Cutroneo, G.; Vermiglio, G.; Centofanti, A.; Rizzo, G.; Runci, M.; Favaloro, A.; Piancino, M.G.; Bracco, P.; Ramieri, G.; Bianchi, F.; Speciale, F.; Arco, A.; Trimarchi, F.

    2016-01-01

    Unilateral posterior crossbite is a widespread, asymmetric malocclusion characterized by an inverse relationship of the upper and lower buccal dental cusps, in the molar and premolar regions, on one side only of the dental arch. Patients with unilateral posterior crossbite exhibit an altered chewing cycles and the crossbite side masseter results to be less active with respect to the contralateral one. Few studies about morphological features of masticatory muscle in malocclusion disorders exist and most of these have been performed on animal models. The aim of the present study was to evaluate morphological and protein expression characteristics of masseter muscles in patients affected by unilateral posterior crossbite, by histological and immunofluorescence techniques. We have used antibody against PAX-7, marker of satellite cells, and against α-, β-, γ-, δ-, ε- and ζ-sarcoglycans which are transmembrane glycoproteins involved in sarcolemma stabilization. By statistical analysis we have evaluated differences in amount of myonucley between contralateral and ipsilateral side. Results have shown: i) altered fibers morphology and atrophy of ipsilateral muscle if compared to the contralateral one; ii) higher number of myonuclei and PAX-7 positive cells in contralateral side than ipsilateral one; iii) higher pattern of fluorescence for all tested sarcoglycans in contralateral side than ipsilateral one. Results show that in unilateral posterior crossbite hypertrophic response of contralateral masseter and atrophic events in ipsilateral masseter take place; by that, in unilateral posterior crossbite malocclusion masticatory muscles modify their morphology depending on the function. That could be relevant in understanding and healing of malocclusion disorders; in fact, the altered balance about structure and function between ipsilateral and contralateral muscles could, long-term, lead and/ or worsen skeletal asymmetries. PMID:27349311

  17. Medical restraints to anterior-posterior motion of the knee.

    PubMed

    Sullivan, D; Levy, I M; Sheskier, S; Torzilli, P A; Warren, R F

    1984-07-01

    We investigated the motion of cadaver knees before and after section of the medial structures and anterior cruciate ligament. The knees were tested using a 5-degrees-of-freedom in vitro knee-testing apparatus that measured anterior-posterior, medial-lateral, and axial displacement as well as internal-external and valgus-varus rotation. The flexion angle could be varied but was fixed for each individual test. A 125-newton anterior-posterior force was applied perpendicular to the tibial shaft and the resulting motion of the knee was measured. In five knees the anterior cruciate ligament was cut first, followed by progressive cuts of the structures on the medial side (superficial medial collateral ligament, deep medial ligament, oblique fibers of the superficial medial ligament, and the posteromedial part of the capsule). Conversely, in five knees the medial structures were progressively cut first, followed by section of the anterior cruciate ligament. Tests were performed after each cut. With an intact anterior cruciate ligament, progressive cutting of the medial side had no effect on anterior and posterior displacements. When section of the medial structures followed cutting of the anterior cruciate ligament, anterior displacement exceeded that seen after isolated section of the anterior cruciate ligament. The anterior and posterior load-tests were repeated with the tibia fixed in 5 degrees of internal and 5 degrees of external rotation. Fixed external rotation had no effect on anterior and posterior displacements. Fixed internal rotation significantly decreased anterior displacement only when both the anterior cruciate ligament and the medial structures were cut.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:6736094

  18. Axial Spondylectomy and Circumferential Reconstruction via a Posterior Approach

    PubMed Central

    Jandial, Rahul; Kelly, Brandon; Bucklen, Brandon; Khalil, Saif; Chen, Mike Y.

    2013-01-01

    Background Spinal metastases of the second cervical vertebra are a subset of tumors that is particularly difficult to address surgically. Previously described techniques require highly morbid circumferential dissection posterior to the pharynx for resection and reconstruction. Objective To perform a biomechanical analysis of instrumented reconstruction configurations used after axial spondylectomy and demonstrate safe use of a novel construct in a patient case report. Methods Several different published and novel reconstruction configurations were inserted into 7 occipitocervical spines that underwent axial spondylectomy. A biomechanical analysis of the constructs’ stiffness in flexion and extension, lateral bending, and rotation was performed. A patient then underwent a posterior-only approach for axial spondylectomy and circumferential reconstruction. Results Biomechanical analysis of different constructs demonstrated that anterior column reconstruction with bilateral cages spanning C1 lateral mass to C3 facet in combination with occipitocervical instrumentation was superior in flexion-extension and equivalent in lateral bending and rotation to currently used constructs. In the patient in which this construct was placed via a posterior-only approach for axial spondylectomy and instrumentation, the patient remained at neurological baseline and demonstrated no recurrence of local disease or failure of instrumentation to date. Conclusion When comparing C1 lateral mass to C3 facet bilateral cage plus occipitocervical instrumentation to existing anterior and posterior constructs, this novel reconstruction is biomechanically equivalent if not superior in performance. In a patient, the posterior-only approach for C2 spondylectomy with the novel reconstruction was safe, durable, and avoided the morbidity of the anterior approach. PMID:23149951

  19. Prevalence of sinus augmentation associated with maxillary posterior implants.

    PubMed

    Seong, Wook-Jin; Barczak, Michael; Jung, Jae; Basu, Saonli; Olin, Paul S; Conrad, Heather J

    2013-12-01

    Pneumatization of the maxillary sinus limits the quantity of alveolar bone available for implant placement and may result in a lack of primary stability and difficulty in achieving osseointegration. The purpose of this study was to retrospectively analyze a group of patients who had implants placed in the posterior maxilla, calculate the prevalence of sinus augmentation, and identify factors related to sinus augmentation. With institutional review board approval, dental records from a population of patients who had implants placed in the maxillary posterior region between January 2000 and December 2004 were used to create a database. Independent variables were classified as continuous (age of the patient at stage 1 implant surgery [S1], time between extraction and S1, time between extraction and sinus augmentation, and time between sinus augmentation and S1) and categorical (gender, implant failure, American Society of Anesthesiologists system classification, smoking, osteoporosis, residual crestal bone height, implant position, implant proximity, prostheses type, and implant diameter and length). The dependent variable was the incidence of a sinus augmentation procedure. Simple logistic regression was used to assess the influence of each factor on the presence of sinus augmentation (P < .05). The final database included 502 maxillary posterior implants with an overall survival rate of 93.2% over a mean follow-up period of 35.7 months. Of 502 implants, 272 (54.2%) were associated with a sinus augmentation procedure. Among variables, residual crestal bone height (P < .001), implant position (P < .001), implant proximity (P < .001), prosthesis type (P < .001), implant failure (P < .01), and implant diameter (P < .01), were statistically associated with sinus augmentation. Within the limitations of this retrospective study, the results suggest that more than half (54.2%) of the maxillary posterior implants were involved with a sinus augmentation procedure. The

  20. Reversible brazing process

    DOEpatents

    Pierce, Jim D.; Stephens, John J.; Walker, Charles A.

    1999-01-01

    A method of reversibly brazing surfaces together. An interface is affixed to each surface. The interfaces can be affixed by processes such as mechanical joining, welding, or brazing. The two interfaces are then brazed together using a brazing process that does not defeat the surface to interface joint. Interfaces of materials such as Ni-200 can be affixed to metallic surfaces by welding or by brazing with a first braze alloy. The Ni-200 interfaces can then be brazed together using a second braze alloy. The second braze alloy can be chosen so that it minimally alters the properties of the interfaces to allow multiple braze, heat and disassemble, rebraze cycles.

  1. Reversal bending fatigue testing

    SciTech Connect

    Wang, Jy-An John; Wang, Hong; Tan, Ting

    2014-10-21

    Embodiments for apparatuses for testing reversal bending fatigue in an elongated beam are disclosed. Embodiments are configured to be coupled to first and second end portions of the beam and to apply a bending moment to the beam and create a pure bending condition in an intermediate portion of the beam. Embodiments are further configured to cyclically alternate the direction of the bending moment applied to the beam such that the intermediate portion of the beam cyclically bends in opposite directions in a pure bending condition.

  2. Inadvertent Trypan Blue Staining of Posterior Capsule during Cataract Surgery Associated with "Argentinian Flag" Event.

    PubMed

    Prinzi, Robert A; Alapati, Neeti M; Gappy, Shawn S; Dilly, Jason S

    2016-01-01

    Trypan blue is common in visualizing the anterior capsule during cataract surgery. Inadvertent staining of the posterior capsule during phacoemulsification is a rare complication and there are few reports in the literature. The proposed mechanism of posterior capsule staining in previous reports includes a compromised zonular apparatus or iris retractors facilitating the posterior flow of trypan blue. We report the first case of trypan blue staining of the posterior capsule associated with the "Argentinian flag" sign. In our case, the "Argentinian flag" allowed the trypan blue to seep between the posterior capsule and the lens, staining the anterior surface of the posterior capsule. PMID:27022495

  3. Reverse Quantum Waves

    NASA Astrophysics Data System (ADS)

    Boyd, Jeffrey

    2010-02-01

    As preposterous as it might sound, if quantum waves travel in the reverse direction from subatomic particles, then most of quantum physics can be explained without quantum weirdness or Schr"odinger's cat. Quantum mathematics is unchanged. The diffraction pattern on the screen of the double slit experiment is the same. This proposal is not refuted by the Innsbruck experiments; this is NOT a hidden local variable theory. Research evidence will be presented that is consistent with the idea waves travel in the opposite direction as neutrons. If one's thinking shifts from forwards to backwards quantum waves, the world changes so drastically it is almost unimaginable. Quantum waves move from the mathematical to the real world, multiply in number, and reverse in direction. Wave-particle duality is undone. In the double slit experiment every part of the target screen is emitting such quantum waves in all directions. Some pass through the two slits. Interference occurs on the opposite side of the barrier than is usually imagined. They impinge on ``S'' and an electron is released at random. Because of the interference it is more likely to follow some waves than others. It follows one and only one wave backward; hitting the screen where it's wave originated. )

  4. Oxytocin Expression and Function in the Posterior Retina: A Novel Signaling Pathway

    PubMed Central

    Halbach, Patrick; Pillers, De-Ann M.; York, Nathaniel; Asuma, Matti P.; Chiu, Michelle A.; Luo, Wenxiang; Tokarz, Sara; Bird, Ian M.; Pattnaik, Bikash R.

    2015-01-01

    Purpose. Oxytocin (OXT) is recognized as an ubiquitously acting nonapeptide hormone that is involved in processes ranging from parturition to neural development. Its effects are mediated by cell signaling that occurs as a result of oxytocin receptor (OXTR) activation. We sought to determine whether the OXT-OXTR signaling pathway is also expressed within the retina. Methods. Immunohistochemistry using cell-specific markers was used to localize OXT within the rhesus retina. Reverse transcriptase PCR and immunohistochemistry were used to assess the expression of OXTR in both human and rhesus retina. Single-cell RT-PCR and Western blot analyses were used to determine the expression of OXTR in cultured human fetal RPE (hfRPE) cells. Human fetal RPE cells loaded with FURA-2 AM were studied by ratiometric Ca2+ imaging to assess transient mobilization of intracellular Ca2+ ([Ca2+]i). Results. Oxytocin was expressed in the cone photoreceptor extracellular matrix of the rhesus retina. Oxytocin mRNA and protein were expressed in the human and rhesus RPE. Oxytocin mRNA and protein expression were observed in cultured hfRPE cells, and exposure of these cells to 100 nM OXT induced a transient 79 ± 1.5 nM increase of [Ca2+]i. Conclusions. Oxytocin and OXTR are present in the posterior retina, and OXT induces an increase in hfRPE [Ca2+]i. These results suggest that the OXT-OXTR signaling pathway is active in the retina. We propose that OXT activation of the OXTR occurs in the posterior retina and that this may serve as a paracrine signaling pathway that contributes to communication between the cone photoreceptor and the RPE. PMID:25593022

  5. Posterior shoulder pain and anterior instability: a preliminary clinical study.

    PubMed

    Castagna, Alessandro; Conti, Marco; Borroni, Mario; Massazza, Giuseppe; Vinci, Enzo; Franceschi, Giorgio; Garofalo, Raffaele

    2008-02-01

    Different clinical tests have been suggested in the literature as significant indicators of anterior shoulder instability. Sometimes patients with recurrent anterior shoulder instability may show some muscular guarding thus making the evaluation of specific clinical tests very difficult. These patients may also report a medical history with posterior shoulder pain that can be also elicited during some clinical manoeuvres. From September 2005 to September 2006 we prospectively studied patients who underwent an arthroscopic anterior capsuloplasty. Shoulder clinical examination was performed including anterior shoulder instability tests (drawer, apprehension and relocation tests). Furthermore the exam was focused on the presence of scapular dyskinesia and posterior shoulder pain. The patients were also evaluated with ASES, Rowe, SST (Simple Shoulder Test), Constant and UCLA (University of California at Los Angeles) scoring system preoperatively and at the latest follow-up time. In the period of this study we observed 16 patients treated for anterior gleno-humeral arthroscopic stabilisation, who preoperatively complained also of a posterior scapular pain. The pain was referred at the level of lower trapezium and upper rhomboids tendon insertion on the medial border of the scapula. It was also reproducible upon local palpation by the examiner. Four of these patients also referred pain in the region of the insertion of the infraspinatus and teres minor. After arthroscopic stabilisation the shoulder was immobilised in a sling with the arm in the neutral rotation for a period of 4 weeks. A single physician supervised shoulder rehabilitation. After a mean time of 6.8 months of follow-up, all the shoulder scores were significantly improved and, moreover, at the same time the patients referred the disappearance of the posterior pain. Posterior scapular shoulder pain seems to be another complaint and sign that can be found in patients affected by anterior shoulder instability

  6. Retroaortic Variant of Reverse Horseshoe Kidney With Butterfly Vertebrae Presenting as Neurogenic Bladder.

    PubMed

    Esen, Baris; Telli, Onur; Ucan, Berna; Fitoz, Suat; Unlu, Agahan; Burgu, Berk; Soygur, Tarkan

    2016-09-01

    Horseshoe kidney is a relatively common congenital anomaly. In 95% of the cases, lower poles are connected to each other. In a small subset, an isthmus connects both upper poles (reverse horseshoe kidney). Almost always, the fusion of kidney poles occurs anterior to the aorta and vena cava. The fusion of renal poles posterior to both aorta and vena cava is extremely rare. Herein, we present a case with multiple rare congenital anomalies-retroaortic variant of reverse horseshoe kidney, retroaortic left renal vein, and butterfly vertebrae. PMID:27282812

  7. Reversed-polarity regions

    NASA Technical Reports Server (NTRS)

    Tang, F.

    1982-01-01

    It is found by a statistical study of 58 reversed-polarity regions (RPRs) covering the 11-year period 1969-1979 that RPRs (1) have a lifespan comparable to normal active regions, (2) do not show a tendency to rotate toward a more normal alignment, and (3) have stable configurations that do not suggest stress due to their anomalous magnetic alignment. As in normal regions, RPR magnetic complexity is found to be the primary factor in flare productivity. Weak-field RPRs produce no flares, and regions with complex spots produce more flares than regions with non-complex spots by a factor of five. The main difference between RPRs and normal regions lies in complex spot frequency, with less that 17% of normal active regions having such spots and fewer than 1.8% having long-lived complex ones, while 41% of RPRs have complex spots and 24% have long-lived complex spots.

  8. A reversible molecular valve

    PubMed Central

    Nguyen, Thoi D.; Tseng, Hsian-Rong; Celestre, Paul C.; Flood, Amar H.; Liu, Yi; Stoddart, J. Fraser; Zink, Jeffrey I.

    2005-01-01

    In everyday life, a macroscopic valve is a device with a movable control element that regulates the flow of gases or liquids by blocking and opening passageways. Construction of such a device on the nanoscale level requires (i) suitably proportioned movable control elements, (ii) a method for operating them on demand, and (iii) appropriately sized passageways. These three conditions can be fulfilled by attaching organic, mechanically interlocked, linear motor molecules that can be operated under chemical, electrical, or optical stimuli to stable inorganic porous frameworks (i.e., by self-assembling organic machinery on top of an inorganic chassis). In this article, we demonstrate a reversibly operating nanovalve that can be turned on and off by redox chemistry. It traps and releases molecules from a maze of nanoscopic passageways in silica by controlling the operation of redox-activated bistable [2]rotaxane molecules tethered to the openings of nanopores leading out of a nanoscale reservoir. PMID:16006520

  9. Multiple stimulus reversible hydrogels

    DOEpatents

    Gutowska, Anna; Krzyminski, Karol J.

    2003-12-09

    A polymeric solution capable of gelling upon exposure to a critical minimum value of a plurality of environmental stimuli is disclosed. The polymeric solution may be an aqueous solution utilized in vivo and capable of having the gelation reversed if at least one of the stimuli fall below, or outside the range of, the critical minimum value. The aqueous polymeric solution can be used either in industrial or pharmaceutical environments. In the medical environment, the aqueous polymeric solution is provided with either a chemical or radioisotopic therapeutic agent for delivery to a specific body part. The primary advantage of the process is that exposure to one environmental stimuli alone will not cause gelation, thereby enabling the therapeutic agent to be conducted through the body for relatively long distances without gelation occurring.

  10. Multiple stimulus reversible hydrogels

    DOEpatents

    Gutowska, Anna; Krzyminski, Karol J.

    2006-04-25

    A polymeric solution capable of gelling upon exposure to a critical minimum value of a plurality of environmental stimuli is disclosed. The polymeric solution may be an aqueous solution utilized in vivo and capable of having the gelation reversed if at least one of the stimuli fall below, or outside the range of, the critical minimum value. The aqueous polymeric solution can be used either in industrial or pharmaceutical environments. In the medical environment, the aqueous polymeric solution is provided with either a chemical or radioisotopic therapeutic agent for delivery to a specific body part. The primary advantage of the process is that exposure to one environmental stimuli alone will not cause gelation, thereby enabling the therapeutic agent to be conducted through the body for relatively long distances without gelation occurring.

  11. Reverse photoacoustic standoff spectroscopy

    DOEpatents

    Van Neste, Charles W.; Senesac, Lawrence R.; Thundat, Thomas G.

    2011-04-12

    A system and method are disclosed for generating a reversed photoacoustic spectrum at a greater distance. A source may emit a beam to a target and a detector measures signals generated as a result of the beam being emitted on the target. By emitting a chopped/pulsed light beam to the target, it may be possible to determine the target's optical absorbance by monitoring the intensity of light collected at the detector at different wavelengths. As the wavelength of light is changed, the target may absorb or reject each optical frequency. Rejection may increase the intensity at the sensing element and absorption may decrease the intensity. Accordingly, an identifying spectrum of the target may be made with the intensity variation of the detector as a function of illuminating wavelength.

  12. Reverse slapper detonator

    DOEpatents

    Weingart, Richard C.

    1990-01-01

    A reverse slapper detonator (70), and methodology related thereto, are provided. The detonator (70) is adapted to be driven by a pulse of electric power from an external source (80). A conductor (20) is disposed along the top (14), side (18), and bottom (16) surfaces of a sheetlike insulator (12). Part of the conductor (20) comprises a bridge (28), and an aperture (30) is positioned within the conductor (20), with the bridge (28) and the aperture (30) located on opposite sides of the insulator (12). A barrel (40) and related explosive charge (50) are positioned adjacent to and in alignment with the aperture (30), and the bridge (28) is buttressed with a backing layer (60). When the electric power pulse vaporizes the bridge (28), a portion of the insulator (12) is propelled through the aperture (30) and barrel (40), and against the explosive charge (50), thereby detonating it.

  13. Reverse Osmosis Optimization

    SciTech Connect

    McMordie Stoughton, Kate; Duan, Xiaoli; Wendel, Emily M.

    2013-08-26

    This technology evaluation was prepared by Pacific Northwest National Laboratory on behalf of the U.S. Department of Energy’s Federal Energy Management Program (FEMP). ¬The technology evaluation assesses techniques for optimizing reverse osmosis (RO) systems to increase RO system performance and water efficiency. This evaluation provides a general description of RO systems, the influence of RO systems on water use, and key areas where RO systems can be optimized to reduce water and energy consumption. The evaluation is intended to help facility managers at Federal sites understand the basic concepts of the RO process and system optimization options, enabling them to make informed decisions during the system design process for either new projects or recommissioning of existing equipment. This evaluation is focused on commercial-sized RO systems generally treating more than 80 gallons per hour.¬

  14. Reverse Osmosis Optimization

    SciTech Connect

    2013-08-01

    This technology evaluation was prepared by Pacific Northwest National Laboratory on behalf of the U.S. Department of Energy’s Federal Energy Management Program (FEMP). The technology evaluation assesses techniques for optimizing reverse osmosis (RO) systems to increase RO system performance and water efficiency. This evaluation provides a general description of RO systems, the influence of RO systems on water use, and key areas where RO systems can be optimized to reduce water and energy consumption. The evaluation is intended to help facility managers at Federal sites understand the basic concepts of the RO process and system optimization options, enabling them to make informed decisions during the system design process for either new projects or recommissioning of existing equipment. This evaluation is focused on commercial-sized RO systems generally treating more than 80 gallons per hour.

  15. Reversibility of skeletal fluorosis.

    PubMed Central

    Grandjean, P; Thomsen, G

    1983-01-01

    At two x ray examinations in 1957 and 1967, 17 cases of skeletal fluorosis were identified among long term cryolite workers in Copenhagen. In 1982 four of these patients were alive, eight to 15 years after exposure had ended. Radiographs were obtained, and the urinary fluoride excretion was measured. A similar picture emerged in all four cases: extensive fading of the sclerosis of trabecular bone in ribs, vertebral bodies, and pelvis, whereas cortical bone thickening and calcification of muscle insertions and ligaments remained virtually unchanged. The fluoride excretion was increased in three cases (with the shortest exposure free period). These findings indicate that with continuous remodelling of bone tissue trabecular sclerosis is slowly reversible and the excess fluoride is excreted in the urine. Images PMID:6626475

  16. Reversibility of skeletal fluorosis.

    PubMed

    Grandjean, P; Thomsen, G

    1983-11-01

    At two x ray examinations in 1957 and 1967, 17 cases of skeletal fluorosis were identified among long term cryolite workers in Copenhagen. In 1982 four of these patients were alive, eight to 15 years after exposure had ended. Radiographs were obtained, and the urinary fluoride excretion was measured. A similar picture emerged in all four cases: extensive fading of the sclerosis of trabecular bone in ribs, vertebral bodies, and pelvis, whereas cortical bone thickening and calcification of muscle insertions and ligaments remained virtually unchanged. The fluoride excretion was increased in three cases (with the shortest exposure free period). These findings indicate that with continuous remodelling of bone tissue trabecular sclerosis is slowly reversible and the excess fluoride is excreted in the urine. PMID:6626475

  17. Biochemical Reversal of Aging

    NASA Astrophysics Data System (ADS)

    Ely, John T. A.

    2006-03-01

    We cite our progress on biochemical reversal of aging. However, it may be circa 2 years before we have necessary substances at low cost. Meanwhile, without them, a number of measures can be adopted providing marked improvement for the problems of aging in modern societies. For example, enzymes are needed to excrete toxins that accelerate aging; Hg is the ultimate toxin that disables all enzymes (including those needed to excrete Hg itself). Low Hg level in the urine, due to loss of excretory ability, causes the diagnosis of Hg toxicity to almost always be missed. Hg sources must be removed from the body! Another example is excess sugar; hyperglycemia decreases intracellular ascorbic acid (AA) by competitively inhibiting the insulin- mediated active transport of AA into cells. Thus, immunity is impaired by low leucocyte AA. AA is needed for new proteins in aging tissues. Humans must supplement AA; their need same as in AA-synthesizing mammals.

  18. Reducing Reversals in Reading and Writing.

    ERIC Educational Resources Information Center

    Heydorn, Bernard L.

    1984-01-01

    Reversals can be remediated in a variety of ways that focus on single symbol reversals (e.g., by tracing overlarge letters or numerals) or whole word reversals (e.g., by using flash cards for identified reverse words). (CL)

  19. On time reversal mirrors

    NASA Astrophysics Data System (ADS)

    Fannjiang, Albert C.

    2009-09-01

    The concept of time reversal (TR) of a scalar wave is reexamined from basic principles. Five different time-reversal mirrors (TRMs) are introduced and their relations are analyzed. For the boundary behavior, it is shown that for a paraxial wave only the monopole TR scheme satisfies the exact boundary condition while for the spherical wave only the MD-mode TR scheme satisfies the exact boundary condition. The asymptotic analysis of the near-field focusing property is presented for two dimensions and three dimensions. It is shown that to have a subwavelength focal spot, the TRM should consist of dipole transducers. The transverse resolution of the dipole TRM is linearly proportional to the distance between the point source and the TRM. The mixed mode TRM has the similar (linear) behavior in three dimensions, but in two dimensions the transverse resolution behaves as the square root of the distance between the point source and the TRM. The monopole TRM is ineffective in focusing below the wavelength. Contrary to the matched field processing and the phase processor, both of which resemble TR, TR in a weak- or non-scattering medium is usually biased in the longitudinal direction, especially when TR is carried out on a single plane with a finite aperture. This is true for all five TR schemes. On the other hand, the TR focal spot has been shown repeatedly in the literature, both theoretically and experimentally, to be centered at the source point when the medium is multiple scattering. A reconciliation of the two seemingly conflicting results is found in the random fluctuations in the intensity of the Green function for a multiple scattering medium and the notion of scattering-enlarged effective aperture.

  20. Reverse Engineering Podkletnov's Experiments

    NASA Astrophysics Data System (ADS)

    Solomon, B. T.

    Experiments reported by Podkletnov et al. suggest that gravity modification is within reach in our lifetimes. Solomon used process models to introduced the concept of non-inertia Ni fields and derived the massless gravitational acceleration formula g = τc2 that is consistent with Hooft's finding that absence of matter no longer guarantees local flatness. Solomon had also shown that many photon experimental results could be modeled without the use of quantum theory. This would imply that neither a quantum nor a relativistic type theory would be indispensible to formulating a theory on gravity modification. This paper, therefore, explores the use of Ni fields and process models to reverse engineer Podkletnov's experiments from first principles to determine a possible theoretical or at least an engineering basis for the observed gravity shielding effects. This paper scrutinizes and documents Podkletnov's papers for detailed experimental clues and applies them to new process models. The paper shows that it is possible to infer gravity modifying effects using non-inertia Ni fields, without taking into consideration the quantum mechanical properties of the ceramic superconducting disc. That is without considering how or why these fields are produced. The modeling suggests that there are two similar but different phenomena present, the stationary disc and spinning disc effects. The observed weight loss with the stationary disc is due to the asymmetric magnetic field and the observed weight loss with the spinning disc is due to the electromagnetic Ni field. There are several keys to reproducing Podkletnov's experimental results, asymmetric fields, dual layer disc, and the presence of both electric and magnetic fields. Finally the paper shows that if the magnetic field was not superconducting, but a regular magnetic field, that the observed weight change should be reversed, and therefore, a non-superconducting disc would lend itself to simpler and easier experimental

  1. Posterior Fixation Techniques in the Subaxial Cervical Spine

    PubMed Central

    Ghori, Ahmer; Makanji, Heeren; Cha, Thomas

    2015-01-01

    This article reviews the historical context, indications, techniques, and complications of four posterior fixation techniques to stabilize the subaxial cervical spine. Specifically, posterior wiring, laminar screw fixation, lateral mass fixation, and pedicle screw fixation are among the common methods of operative fixation of the subaxial cervical spine. While wiring and laminar screw fixation are now rarely used, both lateral mass and pedicle screw fixation are technically challenging and present the risk of significant complications if performed incorrectly. With a sound understanding of anatomy and rigorous preoperative evaluation of bony structures, both lateral mass and pedicle screw fixation provide a safe and reliable method for subaxial cervical spine fixation. PMID:26594602

  2. A case of hypospadias, anterior and posterior urethral valves.

    PubMed

    Carvell, James; Mulik, Roopa

    2013-01-01

    This report outlines the case of a 3-year-old boy whose initial presentation was that of asymptomatic hypertension (lowest recording 148/90), found at preoperative check prior to stage 2-correction surgery for distal hypospadias. Upon diagnosis of true hypertension, an ultrasound of the child's renal tract showed evidence of marked hydronephrosis and calyceal dilatation. On the background of deteriorating renal function (Urea 25.5 and Creatinine 188), a Micturating Cystourethrogram was performed, demonstrating posterior urethral dilatation. With difficulties controlling blood pressure, the child was transferred to Urology care, where resection of a posterior urethral valve (PUV) was undertaken. Despite this, renal function deteriorated further and re-cystoscopy identified an anterior urethral valve (AUV), which was also resected. Renal function, although improved, remains poor and blood pressure is controlled with two anti-hypertensives. To the publisher's knowledge, the association between hypospadias, PUVs and AUVs is as yet undocumented. PMID:24964414

  3. Delayed supratentorial intracerebral hemorrhage following posterior fossa surgery

    PubMed Central

    Salunke, Pravin; Malik, Vinod; Kovai, Priyamvadha; Aggarwal, Ashish; Khandelwal, Niranjan K.

    2016-01-01

    Delayed supratentorial intracerebral hematoma after posterior fossa surgery is uncommon. Only few cases have been reported in the past. The cause has been attributed to sitting position leading to changes in intracranial arterial and venous pressures. We report two cases of delayed intracerebral hematoma following posterior fossa surgery, none of which were operated in sitting position. MR venogram done in one patient showed venous sinus thrombosis. Intracererbal hematoma following infratentorial surgery is uncommon and is possibly due to venous sinus thrombosis leading to venous hypertension. Control of bleeding from venous sinuses due to avulsion of emissary veins during craniotomy/craniectomy possibly induces sinus thrombosis that may propagate antegrade or retrograde, leading to venous hypertension and parenchymal bleed. PMID:27366274

  4. Ogilvie's syndrome following posterior spinal instrumentation in thoraco lumbar trauma

    PubMed Central

    Krishnakumar, R.; Kuzhimattam, Mathew John; Kumar, Gaurav

    2015-01-01

    Objectives: To report unique cases of Ogilvie's syndrome (acute intestinal pseudo-obstruction) following posterior spinal instrumentation in thoraco lumbar trauma. Materials and Methods: A single centre retrospective study. We reviewed the surgical data of 420 patients who underwent thoracolumbar spinal surgery over a period of four years. Two patients who developed post operative Ogilvie's syndromes were identified. Results: The clinical presentation and blood investigations ruled out any infectious pathology. Computed tomography scans ruled out the mechanical obstruction. All patients improved with conservative management. Conclusion: Ogilvie's syndrome should be considered as a differential diagnosis in patients with postoperative significant abdominal distension who had undergone posterior instrumentation for spinal trauma. Early recognition and appropriate conservative treatment would be necessary to prevent complications such as bowel ischemia and perforation. PMID:26692695

  5. SHOULDER POSTERIOR INTERNAL IMPINGEMENT IN THE OVERHEAD ATHLETE

    PubMed Central

    Grant‐Nierman, Meggan; Lucas, Brennen

    2013-01-01

    Posterior internal impingement (PII) of the glenohumeral joint is a common cause of shoulder complex pain in the overhead athlete. This impingement is very different from standard outlet impingement seen in shoulder patients. Internal impingement is characterized by posterior shoulder pain when the athlete places the humerus in extreme external rotation and abduction as in the cocking phase of pitching or throwing. Impingement in this position occurs between the supraspinatus and or infraspinatus and the glenoid rim. Understanding regarding this pathology continues to evolve. Definitive understanding of precipitating factors, causes, presentation and methods of treatment have yet to be determined. A high index of suspicion should be used when attempting to make this diagnosis. This current concepts review presents the current thinking regarding pathophysiology, evaluation, and treatment of this condition. Level of Evidence: 5 PMID:23593557

  6. A case of giant nodular posterior scleritis mimicking choroidal malignancy

    PubMed Central

    Liu, Andrea T; Luk, Fiona O; Chan, Carmen K

    2015-01-01

    To report a case of giant nodular posterior scleritis mimicking a choroidal tumor. A 42-year-old lady with systemic hypertension presented with a 1-week history of unilateral visual loss, pain and redness in her left eye. Examination showed sectoral anterior episcleritis in her left eye as well as a dome-shaped choroidal mass at the inferior-temporal periphery, associated with retinal hemorrhages and subretinal fluid. Systemic evaluation and imaging of the choroidal mass were performed and could not rule out amelanotic choroidal melanoma. At the same time, she was prescribed a 2-week course of oral nonsteroidal anti-inflammatory drug (NSAID) for her sectoral anterior episcleritis. The choroidal mass was found to have resolved completely right before her scheduled fine needle biospy. Diagnosis of nodular posterior scleritis and a trial of oral NSAID can be considered in patients presenting with a choroidal mass before any invasive procedure. PMID:26862098

  7. Ear projection and the posterior auricular muscle insertion.

    PubMed

    Guyuron, B; DeLuca, L

    1997-08-01

    Prominent ears is a common congenital anomaly affecting approximately 5 percent of the general population. The etiology has been attributed to three basic deformities in the ear structure: valgus of the concha with a cranioauricular angle greater than 40 degrees, underfolding of the anthelix, and rarely, hypertrophy of the concha. It is believed that by virtue of its insertion onto the ponticulus, the cranial surface of the concha, the posterior auricular muscle may function to pull the auricle back toward the head. A proximally (anteromedially) displaced insertion site would decrease the length of the effective momentum of the muscle, leading to protrusion of the auricle. This study was conducted to determine if indeed a relationship between the posterior muscle insertion site and ear projection could be established clinically by measuring these parameters intraoperatively in patients presenting for otoplasty and in patients without prominent ears who required conchal cartilage grafts for other procedures. PMID:9252616

  8. Delayed diagnosed posterior interosseous nerve palsy due to intramuscular myxoma

    PubMed Central

    Kursumovic, A; Mattiassich, G; Rath, S

    2013-01-01

    We present a case of posterior interosseous nerve palsy after bowel surgery associated with intramuscular myxoma of the supinator muscle. The initial symptoms of swelling of the forearm made it difficult to distinguish the condition from extravasations after intravenous cannulation. The diagnosis was finally established with nerve conduction studies and MRI 3 months after symptom onset. The patient underwent surgery for removal of the tumour and decompression of the posterior interosseous nerve. The histological examination identified the tumour as intramuscular myxoma and the patient made a full recovery with no recurrence of the lesion until present. Every swelling on the forearm causing neurological disorders is tumour suspected and should be examined clinically as well as electrophysically and radiographically. Early surgery and nerve decompression should follow immediately after the diagnosis. In case of intramuscular myxoma, good recovery of function after surgery with low recurrence risk may be expected. PMID:23576649

  9. Severe complication of posterior nasal packing: Case Report

    PubMed Central

    Pinto, José Antônio; Cintra, Pedro Paulo Vivacqua da Cunha; Sônego, Thiago Branco; Leal, Carolina de Farias Aires; Artico, Marina Spadari; Soares, Josemar dos Santos

    2012-01-01

    Summary Introduction: Severe Epistaxis is common in patients with head trauma, especially when associated with multiple fractures of the face and skull base. Several methods of controlling bleeding that can be imposed. The anterior nasal tapenade associated with posterior Foley catheter is one of the most widespread, and the universal availability of necessary materials or their apparent ease of execution. Methods: Case report on control of severe epistaxis after severe TBI, with posterior nasal packing by Foley catheter and control tomography showing multiple fractures of the skull base and penetration of the probe into the brain parenchyma. Conclusion: This is a rare but possible complication in the treatment of severe nose bleeds associated with fracture of the skull base. This brief report highlights risks related to the method and suggests some care to prevent complications related through a brief literature review. PMID:25991984

  10. Transient presyncope secondary to posterior descending artery occlusion.

    PubMed

    Moffat, Andrew D; Al-Khatib, Jamal T; Michael, Jennifer; Nguyen, Vien X

    2011-01-01

    We describe the case of a 64-year-old male initially presenting with presyncope and bradycardia, without any anginal symptoms or objective evidence of myocardial ischemia. A stress test induced no physical symptoms but revealed a left bundle branch block with multiple preventricular contractions on electrocardiogram. Subsequent catheterization revealed severe obstructive disease throughout the coronary arteries. He was treated percutaneously on two separate heart catheterizations. The presyncope and bradycardia resolved after reperfusion of the posterior descending artery. PMID:24826229

  11. Anterior mitral annulus caseoma: as benign as posterior counterparts?

    PubMed

    Mazzucco, Alessandro; Abbasciano, Riccardo; Onorati, Francesco; Brognoli, Gabriele; Fanti, Diego; Gottin, Leonardo; Faggian, Giuseppe

    2016-01-01

    Mitral annular caseoma is a common incidental finding involving the posterior annulus. It has an innocent nature, with the exception of its endocarditic degeneration and/or a stenotic functional effect when exophytic. We report an exceptionally rare isolated anterior mitral annular caseoma involving also the anterior mitral leaflet and affecting its physiologic systolic movement, thus resulting in a restricting anterior leaflet motion responsible for mitral insufficiency. The case was successfully treated by complex mitral valve repair. PMID:26522681

  12. Hyperintense Acute Reperfusion Marker on FLAIR in Posterior Circulation Infarction

    PubMed Central

    Wenz, Holger; Böhme, Johannes; Al-Zghloul, Mansour; Groden, Christoph

    2016-01-01

    Purpose In the present study, we aimed to investigate the frequency of blood brain barrier injury in posterior circulation infarction as demonstrated by the hyperintense acute reperfusion marker (HARM) on fluid attenuated inversion recovery images (FLAIR). Methods From a MRI report database we identified patients with posterior circulation infarction who underwent MRI, including perfusion-weighted images (PWI), within 12 hours after onset and follow-up MRI within 24 hours and analyzed diffusion-weighted images (DWI), PWI, FLAIR, and MR angiography (MRA). On FLAIR images, the presence of HARM was noted by using pre-specified criteria (focal enhancement in the subarachnoid space and/or the ventricles). Results Overall 16 patients (median age of patients 68.5 (IQR 55.5–82.75) years) with posterior circulation infarction were included. Of these, 13 (81.3%) demonstrated PCA occlusion, and 3 (18.7%) patients BA occlusion on MRA. Initial DWI demonstrated ischemic lesions in the thalamus (68.8%), splenium (18.8%), hippocampus (75%), occipital lobe (81.3%), mesencephalon (18.8%), pons (18.8%), and cerebellum (50%). On follow-up MRA recanalization was noted in 10 (62.5%) patients. On follow-up FLAIR images, HARM was observed in 8 (50%) patients. In all of these, HARM was detected remote from the acute ischemic lesion. HARM was more frequently observed in patients with vessel recanalization (p = 0.04), minor infarction growth (p = 0.01), and smaller ischemic lesions on follow-up DWI (p = 0.05). Conclusions HARM is a frequent finding in posterior circulation infarction and associated with vessel recanalization, minor infarction growth as well as smaller infarction volumes in the course. Neuroradiologists should be cognizant of the fact that HARM may be present on short interval follow-up FLAIR images in patients with acute ischemic infarction who initially underwent MRI and received intravenous gadolinium-based contrast agents. PMID:27326459

  13. Superior Labral Anterior Posterior Lesions of the Shoulder

    PubMed Central

    Malal, Joby Jacob George; Khan, Yousaf; Farrar, Graville; Waseem, Mohammed

    2013-01-01

    Superior labrum anterior and posterior (SLAP) lesion is of fairly recent description and its understanding is rapidly evolving. Its incidence and need for surgical treatment has increased exponentially in line with the increase in shoulder arthroscopies. It is of particular importance in the elite over head athlete and the young. A range of arthroscopic techniques and devices have been described with good functional results. The ability to return to pre injury level of sports remains a concern. PMID:24082975

  14. Posterior dislocation of the hip while playing basketball.

    PubMed

    Tennent, T D; Chambler, A F; Rossouw, D J

    1998-12-01

    Injuries in basketball are usually to the ankles and knees. Dislocation of the hip is usually associated with severe trauma--for example, road traffic accidents. A case is reported here in which a 22 year old club basketball player slipped on landing from a jump shot, forcing him into a side splits position from which he sustained a posterior dislocation of the hip resulting in a sciatic nerve palsy. PMID:9865411

  15. Posterior elbow release and humeral osteotomy for patients with arthrogryposis.

    PubMed

    Zlotolow, Dan A; Kozin, Scott H

    2012-05-01

    Children with arthrogryposis often lack the ability to feed themselves, largely due to limited shoulder external rotation and elbow flexion. Patients who can achieve passive elbow flexion through a surgical release but who cannot externally rotate their shoulders are still unable to reach their mouths with their hands. Combining a posterior elbow capsular release with a simultaneous humeral osteotomy in these patients places the forearm and hand in a much better position for function with minimal additional surgical exposure. PMID:22483178

  16. Intensity-Modulated Arc Therapy for Pediatric Posterior Fossa Tumors

    SciTech Connect

    Beltran, Chris; Gray, Jonathan; Merchant, Thomas E.

    2012-02-01

    Purpose: To compare intensity-modulated arc therapy (IMAT) to noncoplanar intensity-modulated radiation therapy (IMRT) in the treatment of pediatric posterior fossa tumors. Methods and Materials: Nine pediatric patients with posterior fossa tumors, mean age 9 years (range, 6-15 years), treated using IMRT were chosen for this comparative planning study because of their tumor location. Each patient's treatment was replanned to receive 54 Gy to the planning target volume (PTV) using five different methods: eight-field noncoplanar IMRT, single coplanar IMAT, double coplanar IMAT, single noncoplanar IMAT, and double noncoplanar IMAT. For each method, the dose to 95% of the PTV was held constant, and the doses to surrounding critical structures were minimized. The different plans were compared based on conformity, total linear accelerator dose monitor units, and dose to surrounding normal tissues, including the entire body, whole brain, temporal lobes, brainstem, and cochleae. Results: The doses to the target and critical structures for the various IMAT methods were not statistically different in comparison with the noncoplanar IMRT plan, with the following exceptions: the cochlear doses were higher and whole brain dose was lower for coplanar IMAT plans; the cochleae and temporal lobe doses were lower and conformity increased for noncoplanar IMAT plans. The advantage of the noncoplanar IMAT plan was enhanced by doubling the treatment arc. Conclusion: Noncoplanar IMAT results in superior treatment plans when compared to noncoplanar IMRT for the treatment of posterior fossa tumors. IMAT should be considered alongside IMRT when treatment of this site is indicated.

  17. Consolidation of Complex Events via Reinstatement in Posterior Cingulate Cortex.

    PubMed

    Bird, Chris M; Keidel, James L; Ing, Leslie P; Horner, Aidan J; Burgess, Neil

    2015-10-28

    It is well-established that active rehearsal increases the efficacy of memory consolidation. It is also known that complex events are interpreted with reference to prior knowledge. However, comparatively little attention has been given to the neural underpinnings of these effects. In healthy adults humans, we investigated the impact of effortful, active rehearsal on memory for events by showing people several short video clips and then asking them to recall these clips, either aloud (Experiment 1) or silently while in an MRI scanner (Experiment 2). In both experiments, actively rehearsed clips were remembered in far greater detail than unrehearsed clips when tested a week later. In Experiment 1, highly similar descriptions of events were produced across retrieval trials, suggesting a degree of semanticization of the memories had taken place. In Experiment 2, spatial patterns of BOLD signal in medial temporal and posterior midline regions were correlated when encoding and rehearsing the same video. Moreover, the strength of this correlation in the posterior cingulate predicted the amount of information subsequently recalled. This is likely to reflect a strengthening of the representation of the video's content. We argue that these representations combine both new episodic information and stored semantic knowledge (or "schemas"). We therefore suggest that posterior midline structures aid consolidation by reinstating and strengthening the associations between episodic details and more generic schematic information. This leads to the creation of coherent memory representations of lifelike, complex events that are resistant to forgetting, but somewhat inflexible and semantic-like in nature. PMID:26511235

  18. Macular Development in Aggressive Posterior Retinopathy of Prematurity

    PubMed Central

    Pandya, Hemang K.; Faia, Lisa J.; Robinson, Joshua; Drenser, Kimberly A.

    2015-01-01

    Purpose. To report anatomic outcomes after early and confluent laser photocoagulation of the entire avascular retina, including areas in close proximity to the fovea, in patients with APROP. We aspire to demonstrate fundoscopic evidence of transverse growth and macular development following laser treatment in APROP. Methods. Retrospective review of 6 eyes with APROP that underwent confluent laser photocoagulation of the entire avascular retina. Photographic fundoscopic imaging was performed using the RetCam to compare outcomes after treatment. Results. Mean birth weight and gestational age were 704.8 g and 24.33 weeks, respectively. There were 2 females and 1 male. The average time to laser was 9.3 weeks after birth, with the mean postmenstrual age of 34 weeks. Two eyes had zone 1 and 4 eyes had posterior zone 2 disease. Three eyes developed 4A detachments, which were successfully treated. All 6 eyes experienced transverse growth, with expansion of the posterior pole and anterior displacement of the laser treatment. Conclusion. Confluent photocoagulation of the entire avascular retina, regardless of foveal proximity, should be the mainstay for treating APROP. Examination should be conducted within 5–10 days to examine areas previously hidden by neovascularization to ensure prudent therapy. Macular development involves both transverse and anterior-posterior growth. PMID:26167498

  19. Is biologic width of anterior and posterior teeth similar?

    PubMed

    Rasouli Ghahroudi, Amir Alireza; Khorsand, Afshin; Yaghobee, Siamak; Haghighati, Farideh

    2014-01-01

    The biologic width (BW) includes attached epithelial cells and connective tissue attachment complex being very important in the periodontal health during prosthetic treatments as invading this zone can cause bone resorption and gingival recession. The present study investigated biologic width values in the normal periodontium in anterior and posterior teeth. 30 patients that referred from restorative department to periodontics department of Tehran University of medical sciences who need crown lengthening procedure on their teeth with no history of orthodontic, prosthodontic and periodontal treatment were randomly enrolled in this cross-sectional trial. Sulcus depths (SD) as well as the distance between free gingival margin and the bone crest (FB) of anterior and posterior teeth were measured by UNC-15 probe and compared. periodontium thickness was also assessed. The data were subjected to Student t test. Mean BW in the 43 anterior and 47 posterior teeth was measured and not significantly different (1.4651±0.39 mm vs. 1.6312±0.49 mm) was observed; however, BW was significantly more in the teeth with thick periodontium compared to those with thin periodontium (1.703±0.5 vs. 1.408±0.35; P=0.002). BW not only is different in individuals but also could be dissimilar in different teeth and should be calculated independently prior to restorative treatments. PMID:25325207

  20. Conservative management of posterior ankle impingement: a case report

    PubMed Central

    Senécal, Isabelle; Richer, Nadia

    2016-01-01

    Objective: To describe the pain and functional improvements of a patient with posterior ankle impingement following a treatment plan incorporating soft tissue therapy, chiropractic adjustment and a progressive rehabilitation program. Clinical Features: A 37-year- old male presented with posterolateral ankle pain exacerbated by plantar flexion two weeks after sustaining an inversion ankle sprain. Oedema was present and the patient was describing a sensation of instability while walking. The initial diagnosis of lateral ankle sprain was found to be complicated by a posterior ankle impingement caused by a tenosynovitis of the flexor hallucis longus sheath suspected during the physical examination and confirmed by MRI. Intervention and Outcome: The patient was treated over a 14-week period. Soft tissue therapy, a rehabilitation program and cortisone injection were used to treat this condition. A precise description of the rehabilitation program that contains open kinetic chain, closed kinetic chain, proprioception, and conditioning exercises prescribed to the patient is given. After the treatment plan, the patient returned to play pain free and had no daily living restrictions. Summary: A protocol including rest, soft tissue therapy, open and closed kinetic chain exercises, sport-specific exercises and cortisone injection appeared to facilitate complete recovery of this patient’s posterior ankle impingement. PMID:27385836

  1. Posterior segment findings in a patient with immunotactoid glomerulonephritis

    PubMed Central

    Gupta, Aditi; Prabhu, Rangarajan Venugopal; Patel, Amit K.; Sivaraj, Ramesh

    2015-01-01

    Purpose: To present a case with posterior segment findings in a patient with cloudy corneas secondary to immunotactoid glomerulonephritis (ITG). Methods: A 57-year-old female was known to have bilateral cloudy corneas diagnosed 12 years ago secondary to immunotactoid glomerulonephritis. Clinically, fundus examination was difficult to visualise due to the density of her corneal opacities. Results: B-scan ultrasound revealed significant retino-choroidal & non-inflammatory scleral thickening. The macula also showed signs of thickening in both eyes. Optical coherence tomography (OCT) showed thinning of the inner retinal layers and significant choroidal folds in both eyes. Electrodiagnostic tests (EDT) concluded loss of retinal ganglion cells with preservation of retinal function in both eyes. Conclusion: This case widens the spectrum of findings seen in patients diagnosed with Immunotactoid Glomerulonephritis and alerts us to undertake detailed posterior segment examination where possible. Ocular coherence tomography (OCT) and B-scan ultrasonography are important adjuvants to help assess the posterior segment in patients with corneal opacities secondary to ITG.

  2. Effect of four different intraocular lenses on posterior capsule opacification

    PubMed Central

    Duman, Rahmi; Karel, Fatih; Özyol, Pelin; Ateş, Can

    2015-01-01

    AIM To evaluate the impact of 4 different intraocular lenses (IOLs) on posterior capsule opacification (PCO) by comparing the neodymium: yttrium-aluminum-garnet (Nd:YAG) laser capsulotomy rates. METHODS This retrospective study included 4970 eyes of 4013 cataract patients who underwent phacoemulsification and IOL implantation between January 2000 and January 2008 by the same surgeon at one clinic. Four different IOLs were assessed. The outcome parameter was the incidence of Nd:YAG laser posterior capsulotomies. RESULTS An Nd:YAG laser posterior capsulotomy was performed in 153 (3.07%) of the 4970 eyes. The mean follow-up time was 84mo for all of the IOL groups. The percentage of eyes developing PCO was significantly greater for the acrylic hydrophilic IOLs than for the hydrophobic IOLs, although eyes with acrylic hydrophilic IOLs did not require Nd:YAG laser capsulotomy as soon as eyes with acrylic hydrophobic IOLs. There was no difference between the long-term PCO rates when 1- and 3-piece acrylic hydrophobic IOLs were compared or when IOLs made of the same material but with different haptic angles were compared. CONCLUSION In this study, eyes with acrylic hydrophilic IOLs were more likely to develop PCO than those with acrylic hydrophobic IOLs. The lens design (1-piece versus 3-piece and varying haptic angles) did not affect the PCO rate. PMID:25709920

  3. [Posterior genital prolapse following the Burch method of colposuspension].

    PubMed

    Flores Rosas, S; Flores Carreras, O; Cabrera Jacome, R

    1999-10-01

    The aim of this paper was to know the prevalence of genital prolapse after the Burch procedure. Also to intend knowing if the associate surgery for vaginal relaxation used in our Urogynecologic Service is working well. Seventy four patients with more than six months after the Burch procedure were addressed from October 1995 to January 1996. Special attention was put to detect pelvis floor defects in specific vaginal sites (urethra, bladder, vaginal ápex, cul de sac and distal posterior wall). The prevalence of urethrocele was 2.7%, cystocele 50.6%, almost of all were mild. None severe cystocele was detected. Cervical prolapse was present in 21.3%, vault prolapse in 9.3% and enterocele 41.9%. The posterior colporraphy seems to be useful to prevent the vault prolapse and the enterocele. On the contrary the Moschowitz procedure seems not to be useful in this aspect. In order to diminish the prevalence of genital prolapse posterior to Burch procedure it would be better to improve the preoperative vaginal examination in order to do segmentary prolapse diagnosis and also to stablish an individualized surgical treatment of them. PMID:10582398

  4. Microscopic Posterior Transdural Resection of Cervical Retro-Odontoid Pseudotumors.

    PubMed

    Fujiwara, Yasushi; Manabe, Hideki; Sumida, Tadayoshi; Tanaka, Nobuhiro; Hamasaki, Takahiko

    2015-12-01

    Retro-odontoid pseudotumors are noninflammatory masses formed posterior to the odontoid process. Because of their anatomy, the optimal surgical approach for resecting pseudotumors is controversial. Conventionally, 3 approaches are used: the anterior transoral approach, the lateral approach, and the posterior extradural approach; however, each approach has its limitations. The posterior extradural approach is the most common; however, it remains challenging due to severe epidural veins. Although regression of pseudotumors after fusion surgery has been reported, direct decompression and a pathologic diagnosis are ideal when the pseudotumor is large. We therefore developed a new microscopic surgical technique; transdural resection. After C1 laminectomy, the dorsal and ventral dura was incised while preserving the arachnoid. Removal of the pseudotumor was performed and both of the dura were repaired. The patient's clinical symptoms subsequently improved and the pathologic findings showed degenerative fibrocartilaginous tissue. In addition, no neurological deterioration, central spinal fluid leakage, or arachnoiditis was observed. Currently, the usefulness of the transdural approach has been reported for cervical and thoracic disk herniation. According to our results, the transdural approach is recommended for resection of retro-odontoid pseudotumors because it enables direct decompression of the spinal cord and a pathologic diagnosis. PMID:26544168

  5. Contributions of cat posterior parietal cortex to visuospatial discrimination.

    PubMed

    Lomber, S G; Payne, B R

    2000-01-01

    The purpose of the present study was to examine the contributions made by cat posterior parietal cortex to the analyses of the relative position of objects in visual space. Two cats were trained on a landmark task in which they learned to report the position of a landmark object relative to a right or left food-reward chamber. Subsequently, three pairs of cooling loops were implanted bilaterally in contact with visuoparietal cortices forming the crown of the middle suprasylvian gyrus (MSg; architectonic area 7) and the banks of the posterior-middle suprasylvian sulcus (pMS sulcal cortex) and in contact with the ventral-posterior suprasylvian (vPS) region of visuotemporal cortex. Bilateral deactivation of pMS sulcal cortex resulted in a profound impairment for all six tested positions of the landmark, yet bilateral deactivation of neither area 7 nor vPS cortex yielded any deficits. In control tasks (visual orienting and object discrimination), there was no evidence for any degree of attentional blindness or impairment of form discrimination during bilateral deactivation of pMS cortex. Therefore, we conclude that bilateral cooling of pMS cortex, but neither area 7 nor vPS cortex, induces a specific deficit in spatial localization as examined with the landmark task. These observations have significant bearing on our understanding of visuospatial processing in cat, monkey, and human cortices. PMID:11153650

  6. Microscopic Posterior Transdural Resection of Cervical Retro-Odontoid Pseudotumors

    PubMed Central

    Manabe, Hideki; Sumida, Tadayoshi; Tanaka, Nobuhiro; Hamasaki, Takahiko

    2015-01-01

    Retro-odontoid pseudotumors are noninflammatory masses formed posterior to the odontoid process. Because of their anatomy, the optimal surgical approach for resecting pseudotumors is controversial. Conventionally, 3 approaches are used: the anterior transoral approach, the lateral approach, and the posterior extradural approach; however, each approach has its limitations. The posterior extradural approach is the most common; however, it remains challenging due to severe epidural veins. Although regression of pseudotumors after fusion surgery has been reported, direct decompression and a pathologic diagnosis are ideal when the pseudotumor is large. We therefore developed a new microscopic surgical technique; transdural resection. After C1 laminectomy, the dorsal and ventral dura was incised while preserving the arachnoid. Removal of the pseudotumor was performed and both of the dura were repaired. The patient’s clinical symptoms subsequently improved and the pathologic findings showed degenerative fibrocartilaginous tissue. In addition, no neurological deterioration, central spinal fluid leakage, or arachnoiditis was observed. Currently, the usefulness of the transdural approach has been reported for cervical and thoracic disk herniation. According to our results, the transdural approach is recommended for resection of retro-odontoid pseudotumors because it enables direct decompression of the spinal cord and a pathologic diagnosis. PMID:26544168

  7. The evolution of alexia and simultanagnosia in posterior cortical atrophy.

    PubMed

    Mendez, M F; Cherrier, M M

    1998-04-01

    Early alexia and higher visual impairments characterize Posterior cortical atrophy (PCA), a progressive dementing syndrome most often caused by Alzheimer disease. Posterior cortical atrophy is rare, and the nature of the visual impairments in PCA are unclear. The authors observed two patients who had an insidiously progressive reading difficulty characterized by letter-by-letter reading and otherwise intact cognitive functions. Over time, these patients developed "ventral simultanagnosia" with preserved detection of multiple stimuli but inability to interpret whole scenes. Subsequently, they progressed to Balint syndrome with "dorsal simultanagnosia," optic ataxia, and oculomotor apraxia. Structural imaging was normal, but functional imaging revealed posterior cortical dysfunction. On a letter reading task, both patients had a word superiority effect, and on a whole word reading task, they could not read most words with missing or crosshatched letters. An inability to assess whole scenes progressed to an inability to detect more than one stimulus in an array. These findings suggest an evolution of PCA with progressive difficulty in visual integration beginning with letters, progressing to whole scenes, and culminating in Balint syndrome. These changes may reflect an extension of the pathophysiology of PCA from the extrastriate visual cortex to its occipitotemporal and occipitoparietal connections. PMID:9652488

  8. Rapid Visual Deterioration Caused by Posterior Fossa Arachnoid Cyst.

    PubMed

    Shin, Chang Jin; Rho, Myeongho; Won, Yu Sam; Kim, Si On

    2016-05-01

    Posterior fossa is a site next to the middle fossa where arachnoid cyst frequently occurs. Generally, most arachnoid cysts are asymptomatic and are found incidentally in most cases. Although arachnoid cysts are benign and asymptomatic lesions, patients with posterior fossa arachnoid cysts often complain of headaches, gait disturbance, and ataxia due to the local mass effects on the cerebellum. We observed a patient with a posterior fossa arachnoid cyst who had visual symptoms and a headache, but did not have gait disturbance and ataxia. We recommended an emergency operation for decompression, but the patient refused for personal reasons. After 7 days, the patient revisited our hospital in a state of near-blindness. We suspected that the arachnoid cyst induced the hydrocephalus and thereby the enlarged third ventricle directly compressed optic nerves. Compressed optic nerves were rapidly aggravated during the critical seven days; consequently, the patient's vision was damaged despite the operation. Considering the results of our case, it is important to keep in mind that the aggravation of symptoms cannot be predicted; therefore, symptomatic arachnoid cysts should be treated without undue delay. PMID:27226868

  9. Rapid Visual Deterioration Caused by Posterior Fossa Arachnoid Cyst

    PubMed Central

    Shin, Chang Jin; Rho, Myeongho; Won, Yu Sam

    2016-01-01

    Posterior fossa is a site next to the middle fossa where arachnoid cyst frequently occurs. Generally, most arachnoid cysts are asymptomatic and are found incidentally in most cases. Although arachnoid cysts are benign and asymptomatic lesions, patients with posterior fossa arachnoid cysts often complain of headaches, gait disturbance, and ataxia due to the local mass effects on the cerebellum. We observed a patient with a posterior fossa arachnoid cyst who had visual symptoms and a headache, but did not have gait disturbance and ataxia. We recommended an emergency operation for decompression, but the patient refused for personal reasons. After 7 days, the patient revisited our hospital in a state of near-blindness. We suspected that the arachnoid cyst induced the hydrocephalus and thereby the enlarged third ventricle directly compressed optic nerves. Compressed optic nerves were rapidly aggravated during the critical seven days; consequently, the patient's vision was damaged despite the operation. Considering the results of our case, it is important to keep in mind that the aggravation of symptoms cannot be predicted; therefore, symptomatic arachnoid cysts should be treated without undue delay. PMID:27226868

  10. Magnetic reversals and mass extinctions

    NASA Technical Reports Server (NTRS)

    Raup, D. M.

    1985-01-01

    The results of a study of reversals of the earth's magnetic field over the past 165 Myr are presented. A stationary periodicity of 30 Myr emerges which predicts pulses of increased reversal activity centered at 10, 40, 70, . . . Myr before the present. The correlation between the reversal intensity and biological extinctions is examined, and a nontrivial discrepancy is found between the magnetic and extinction periodicity.

  11. Geomagnetic Reversals during the Phanerozoic.

    PubMed

    McElhinny, M W

    1971-04-01

    An antalysis of worldwide paleomagnetic measurements suggests a periodicity of 350 x 10(6) years in the polarity of the geomagnetic field. During the Mesozoic it is predominantly normal, whereas during the Upper Paleozoic it is predominantly reversed. Although geomagnetic reversals occur at different rates throughout the Phanerozoic, there appeaars to be no clear correlation between biological evolutionary rates and reversal frequency. PMID:17735224

  12. 21 CFR 886.4392 - Nd:YAG laser for posterior capsulotomy and peripheral iridotomy.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Nd:YAG laser for posterior capsulotomy and...:YAG laser for posterior capsulotomy and peripheral iridotomy. (a) Identification. The Nd:YAG laser for... laser intended for disruption of the posterior capsule or the iris via optical breakdown. The...

  13. 21 CFR 886.4392 - Nd:YAG laser for posterior capsulotomy and peripheral iridotomy.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Nd:YAG laser for posterior capsulotomy and...:YAG laser for posterior capsulotomy and peripheral iridotomy. (a) Identification. The Nd:YAG laser for... laser intended for disruption of the posterior capsule or the iris via optical breakdown. The...

  14. ASYMMETRIC SOLAR POLAR FIELD REVERSALS

    SciTech Connect

    Svalgaard, Leif; Kamide, Yohsuke

    2013-01-20

    The solar polar fields reverse because magnetic flux from decaying sunspots moves toward the poles, with a preponderance of flux from the trailing spots. If there is a strong asymmetry, in the sense that most activity is in the northern hemisphere, then that excess flux will move toward the north pole and reverse that pole first. If there is more activity in the south later on, then that flux will help to reverse the south pole. In this way, two humps in the solar activity and a corresponding difference in the time of reversals develop (in the ideal case). Such a difference was originally noted in the very first observation of polar field reversal just after the maximum of the strongly asymmetric solar cycle 19, when the southern hemisphere was most active before sunspot maximum and the south pole duly reversed first, followed by the northern hemisphere more than a year later, when that hemisphere became most active. Solar cycles since then have had the opposite asymmetry, with the northern hemisphere being most active before solar maximum. We show that polar field reversals for these cycles have all happened in the north first, as expected. This is especially noteworthy for the present solar cycle 24. We suggest that the association of two or more peaks of solar activity when separated by hemispheres with correspondingly different times of polar field reversals is a general feature of the cycle, and that asymmetric polar field reversals are simply a consequence of the asymmetry of solar activity.

  15. Anterior-posterior asymmetry in iris mechanics measured by indentation.

    PubMed

    Whitcomb, Julie E; Amini, Rouzbeh; Simha, Narendra K; Barocas, Victor H

    2011-10-01

    Indentation and histological analysis of the porcine iris were done to assess the relative stiffness of the anterior (stroma) and posterior (dilator and sphincter) layers. The dimensions of the constituent structures were documented histologically by staining with a monoclonal anti-human α-smooth muscle actin antibody to determine the location of the stroma, sphincter, and dilator. Intact porcine irides (4-8 h post-mortem) were bisected into two equal C-shaped halves to indent both surfaces. Indentation experiments were performed using a 1 mm cylindrical indenter tip. The load-displacement curve for each experiment was used to estimate effective instantaneous and equilibrium moduli for the anterior and posterior surfaces of the tissue. A total of 18 irides (9 pairs) with 3-5 indentations per iris surface was performed. The average thickness of the samples was 550 μm; the indentation depth was limited to 60-100 μm depending on the thickness of the sample at each point. Posterior surface indentation gave larger forces than anterior, with the resulting instantaneous modulus of 6.0 ± 0.6 kPa versus 4.0 ± 0.5 kPa (mean ± 95% CI, n = 45, p < 0.001) and equilibrium modulus of 4.4 ± 0.9 versus 2.3 ± 0.3 (p = 0.007). The stress-relaxation analysis revealed that the anterior surface had a shorter relaxation time (121.31 ± 6.84 s) than the posterior surface (210.61 ± 9.41 s, p = 0.03), perhaps due to the permeability of the stroma. Recognizing that our effective modulus calculations in this study did not account for heterogeneity, viscoelasticity, or poroelasticity, we conclude that the posterior components of the iris - dilator, pigment epithelium, and sphincter - are on average stiffer than the stroma and anterior border layer. PMID:21787771

  16. Arthroscopic posterior cruciate ligament reconstruction with allograft versus autograft

    PubMed Central

    Sun, Xiujiang; Zhang, Jianfeng; Qu, Xiaoyi

    2015-01-01

    Introduction The aim of the study was to compare and analyze retrospectively the outcomes of arthroscopic posterior cruciate ligament reconstruction with autograft versus allograft. Material and methods Seventy-one patients who underwent arthroscopic posterior cruciate ligament reconstruction with an autograft or allograft met our inclusion criteria. There were 36 patients in the autograft group and 35 patients in the allograft group. All the patients were evaluated by physical examination and a functional ligament test. Comparative analysis was done in terms of operation time, incision length, fever time, postoperative infection rate, incidence of numbness and dysesthesia around the incision, as well as a routine blood test. Results The average follow-up of the autograft group was 3.2 ±0.2 years and that of the allograft group was 3.3 ±0.6 years; there was no significant difference (p > 0.05). No differences existed in knee range of motion, Lysholm scores, International Knee Documentation Committee standard evaluation form and Tegner activity score at final follow-up (p > 0.05), except that patients in the allograft group had a shorter operation time and incision length and a longer fever time (p < 0.05). We found a difference in posterior drawer test and KT-2000 arthrometer assessment (p < 0.05). The posterior tibia displacement averaged 3.8 ±1.5 mm in the autograft group and 4.8 ±1.7 mm in the allograft group (p < 0.05). The incidence of numbness and dysesthesia around the incision in the autograft group was higher than that in the allograft group (p < 0.05). There was no infection postoperatively. The white blood cells and neutrophils in the allograft group increased more than those in the autograft group postoperatively (p < 0.05). Conclusions Both groups of patients had satisfactory outcomes after the operation. However, in the instrumented posterior laxity test, the autograft gave better results than the allograft. No differences in functional scores

  17. Posterior corneal curvature changes following Refractive Small Incision Lenticule Extraction

    PubMed Central

    Ganesh, Sri; Patel, Utsav; Brar, Sheetal

    2015-01-01

    Purpose To compare the posterior corneal curvature changes, in terms of corneal power and asphercity, following Refractive Small Incision Lenticule Extraction (ReLEx SMILE) procedure for low, moderate, and high myopia. Methods This retrospective, non randomized, comparative, interventional trial; included 52 eyes of 26 patients, divided in three groups: low myopia (myopia ≤3 D [diopters] spherical equivalent [SE]), moderate myopia (myopia >3 D and <6 D SE), and high myopia (myopia ≥6 D SE). All patients were treated for myopia and myopic astigmatism using ReLEx SMILE. The eyes were examined pre-operatively and 3 months post-operatively using SCHWIND SIRIUS, a three-dimensional rotating Scheimpflug camera with a Placido disc topographer to assess corneal changes with regard to keratometric power and asphericity of the cornea. Results A statistically significant increase in mean keratometric power in the 3, 5, and 7 mm zones of the posterior corneal surface compared with its pre-ReLEx SMILE value was detected after 3 months in the moderate myopia group (pre-operative [pre-op] −6.14±0.23, post-operative [post-op] −6.29±0.22, P<0.001) and high myopia group (pre-op −6.19±0.16, post-op −6.4±0.18, P<0.001), but there was no significant change in keratometric power of the posterior surface in the low myopia group (pre-op −5.87±0.17, post-op −6.06±0.29, P=0.143). Asphericity (Q-value) of the posterior surface changed significantly (P<0.001) after ReLEx SMILE in the moderate myopia group in the 3, 5, and 7 mm zones, and in the high myopia group in the 3 and 7 mm zones; but there was no significant change in the Q-value in the low myopia group in all three zones (pre-op 0.23±0.43, post-op −0.40±0.71, P=0.170), and in the high myopia group in the 5 mm zone (P=0.228). Conclusion ReLEx SMILE causes significant changes in posterior corneal keratometric power and asphericity in moderate and high myopia, but the effect is subtle and insignificant in low

  18. [Updates of ossification of posterior longitudinal ligament. Clinical results and complication of surgery for thoracic myelopathy due to ossification of posterior longitudinal ligament].

    PubMed

    Yamazaki, Masashi

    2009-10-01

    We performed 3 types of surgical procedures for thoracic myelopathy due to OPLL : posterior decompression, OPLL-extirpation, and posterior decompression with instrumented fusion (PDF) . A considerable degree of neurological recovery was obtained in all patients who underwent PDF, despite the anterior impingement of the spinal cord by OPLL remaining. In addition, the rate of post-operative complications was extremely low with PDF, when compared with posterior decompression and OPLL-extirpation groups. We recommend that one stage posterior decompression with instrumented fusion be selected for cases in whom the spinal cord is severely damaged pre-operatively. PMID:19794260

  19. Posterior reversible encephalopathy syndrome after pediatric heart transplantation: Increased risk for children with preexisting Glenn/Fontan physiology.

    PubMed

    Eilers, Braiden; Albers, Erin; Law, Yuk; McMullan, D Mike; Shaw, Dennis; Kemna, Mariska

    2016-06-01

    Identification of risk factors for PRES after organ transplant can improve early detection and avoid permanent neurological injury. High calcineurin-inhibitor levels and hypertension are recognized risk factors for PRES in adult transplant recipients. Limited data exist regarding PRES after pediatric HTx, with studies limited to case reports. We performed a retrospective review of 128 pediatric HTx recipients to identify risk factors for PRES. Seven of 128 (5.5%) recipients developed PRES at a median of 10 days (5-57) after HTx. The median age of recipients with PRES was 10.0 yr (5.7-19.0), compared to 1.4 yr (0.0-19.8) for recipients without PRES (p = 0.010). Fewer than half of recipients with PRES had elevated post-transplant calcineurin-inhibitor levels (n = 3) and/or preceding severe hypertension (n = 3). Four of seven who developed PRES (57%) had pretransplant Glenn or Fontan physiology (G/F). G/F was a significant risk factor for PRES (RR 4.99, 95% CI: 1.19-21.0, p = 0.036). Two recipients (29%), both with severe PRES, had residual neurological symptoms. In summary, PRES occurred in 5.5% of pediatric HTx recipients and presented early after HTx. All recipients with PRES were > 5 yr. Patients with pretransplant G/F were at increased risk, a risks factor not previously described. PMID:27139146

  20. Unusual posterior reversible encephalopathy syndrome in a case of influenza A/H1N1 infection.

    PubMed

    Locuratolo, Nicoletta; Mannarelli, Daniela; Colonnese, Claudio; Pauletti, Caterina; Antonaci, Laura; Ferretti, Giancarlo; Fattapposta, Francesco

    2012-10-15

    Central nervous system involvement is an uncommon though potentially a severe complication during influenza infection; the pathogenic mechanisms of the neurological syndromes described in humans are largely unknown. We describe a case of a 51-year-old man who presented with fever and behavioral changes but no focal neurological deficits. The next day, the condition rapidly evolved into a severe neurological syndrome with recurrent focal motor seizures with secondary generalization. At the brain MRI, FLAIR disclosed a slight area of increased signal in the left mesial frontal cortex extending to the frontopolar area and insula. At DWI, a mild hyperintensity was evident in the mesial-frontopolar cortex, with normal ADC values. MR perfusion was indicative of severe hypoperfusion. Fungal, bacterial and viral cultures in CSF, blood and urine were negative. The nasopharyngeal swab PCR was positive for the H1N1-influenza A virus. The patient was thus treated and by day five the neurological examination results had returned to normal. A follow-up MRI, performed two weeks later, only revealed a residual slight hyperintensity in the left medial frontal cortex. The onset of a rapidly evolving encephalopathy syndrome, its close association with a MRI brain pattern of acute vasogenic edema and favorable outcome support a diagnosis of PRES during influenza A infection. However, the topographic characteristics of the cerebral lesion seem to define a PRES with an atypical pattern. PMID:22910147

  1. Time Reversal Violation

    SciTech Connect

    Quinn, H; /SLAC

    2009-01-27

    This talk briefly reviews three types of time-asymmetry in physics, which I classify as universal, macroscopic and microscopic. Most of the talk is focused on the latter, namely the violation of T-reversal invariance in particle physics theories. In sum tests of microscopic T-invariance, or observations of its violation, are limited by the fact that, while we can measure many processes, only in very few cases can we construct a matched pair of process and inverse process and observe it with sufficient sensitivity to make a test. In both the cases discussed here we can achieve an observable T violation making use of flavor tagging, and in the second case also using the quantum properties of an antisymmetric coherent state of two B mesons to construct a CP-tag. Both these tagging properties depend only on very general properties of the flavor and/or CP quantum numbers and so provide model independent tests for T-invariance violations. The microscopic laws of physics are very close to T-symmetric. There are small effects that give CP- and T-violating processes in three-generation-probing weak decays. Where a T-violating observable can be constructed we see the relationships between T-violation and CP-violation expected in a CPT conserving theory. These microscopic effects are unrelated to the 'arrow of time' that is defined by increasing entropy, or in the time direction defined by the expansion of our Universe.

  2. Reversible micromachining locator

    DOEpatents

    Salzer, Leander J.; Foreman, Larry R.

    1999-01-01

    This invention provides a device which includes a locator, a kinematic mount positioned on a conventional tooling machine, a part carrier disposed on the locator and a retainer ring. The locator has disposed therein a plurality of steel balls, placed in an equidistant position circumferentially around the locator. The kinematic mount includes a plurality of magnets which are in registry with the steel balls on the locator. In operation, a blank part to be machined is placed between a surface of a locator and the retainer ring (fitting within the part carrier). When the locator (with a blank part to be machined) is coupled to the kinematic mount, the part is thus exposed for the desired machining process. Because the locator is removably attachable to the kinematic mount, it can easily be removed from the mount, reversed, and reinserted onto the mount for additional machining. Further, the locator can likewise be removed from the mount and placed onto another tooling machine having a properly aligned kinematic mount. Because of the unique design and use of magnetic forces of the present invention, positioning errors of less than 0.25 micrometer for each machining process can be achieved.

  3. Reversible micromachining locator

    DOEpatents

    Salzer, L.J.; Foreman, L.R.

    1999-08-31

    This invention provides a device which includes a locator, a kinematic mount positioned on a conventional tooling machine, a part carrier disposed on the locator and a retainer ring. The locator has disposed therein a plurality of steel balls, placed in an equidistant position circumferentially around the locator. The kinematic mount includes a plurality of magnets which are in registry with the steel balls on the locator. In operation, a blank part to be machined is placed between a surface of a locator and the retainer ring (fitting within the part carrier). When the locator (with a blank part to be machined) is coupled to the kinematic mount, the part is thus exposed for the desired machining process. Because the locator is removably attachable to the kinematic mount, it can easily be removed from the mount, reversed, and reinserted onto the mount for additional machining. Further, the locator can likewise be removed from the mount and placed onto another tooling machine having a properly aligned kinematic mount. Because of the unique design and use of magnetic forces of the present invention, positioning errors of less than 0.25 micrometer for each machining process can be achieved. 7 figs.

  4. Reverse genetics of avian metapneumoviruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An overview of avian metapneumovirus (aMPV) infection in turkeys and development of a reverse genetics system for aMPV subgroup C (aMPV-C) virus will be presented. By using reverse genetics technology, we generated recombinant aMPV-C viruses containing a different length of glycoprotein (G) gene or...

  5. Preference Reversal in Multiattribute Choice

    ERIC Educational Resources Information Center

    Tsetsos, Konstantinos; Usher, Marius; Chater, Nick

    2010-01-01

    A central puzzle for theories of choice is that people's preferences between options can be reversed by the presence of decoy options (that are not chosen) or by the presence of other irrelevant options added to the choice set. Three types of reversal effect reported in the decision-making literature, the attraction, compromise, and similarity…

  6. Reverse Transfer Project, Summer 1986.

    ERIC Educational Resources Information Center

    Reis, Elizabeth

    In 1986, a Reverse Transfer Project was initiated at Moraine Valley Community College (MVCC) in order to promote the summer school attendance at MVCC of "reverse transfer" students (i.e., students who attended another institution during the regular academic year). A mailing, containing a cover letter, informational brochure, summer catalog, and…

  7. Reversal of novel oral anticoagulants.

    PubMed

    Abo-Salem, Elsayed; Becker, Richard C

    2016-04-01

    The development of a new generation of non-vitamin K oral anticoagulants represents a potential breakthrough in the management of patients with thrombotic diseases, disorders and conditions. While a large and growing body of evidence from large-scale clinical trials and registries supports a favorable safety profile, having a means to rapidly reverse their anticoagulant effects represents an unmet need among practicing clinicians. Several targeted reversal agents are currently in development and the early results are promising. Idarucizumab is a monoclonal antibody that can immediately and specifically reverse dabigatran. Andexanet alfa is a recombinant modified factor Xa that can bind and reverse oral and parenteral factor Xa inhibitors, including rivaroxaban, apixaban and edoxaban, and low molecular weight heparin. Aripazine is a small molecule that can reverse the action of factor Xa inhibitors and possibly dabigatran as well through non-covalent binding and charge-charge interactions. PMID:26939028

  8. Classical Analog to Entanglement Reversibility

    NASA Astrophysics Data System (ADS)

    Chitambar, Eric; Fortescue, Ben; Hsieh, Min-Hsiu

    2015-08-01

    In this Letter we study the problem of secrecy reversibility. This asks when two honest parties can distill secret bits from some tripartite distribution pX Y Z and transform secret bits back into pX Y Z at equal rates using local operation and public communication. This is the classical analog to the well-studied problem of reversibly concentrating and diluting entanglement in a quantum state. We identify the structure of distributions possessing reversible secrecy when one of the honest parties holds a binary distribution, and it is possible that all reversible distributions have this form. These distributions are more general than what is obtained by simply constructing a classical analog to the family of quantum states known to have reversible entanglement. An indispensable tool used in our analysis is a conditional form of the Gács-Körner common information.

  9. Parkinson's disease managing reversible neurodegeneration.

    PubMed

    Hinz, Marty; Stein, Alvin; Cole, Ted; McDougall, Beth; Westaway, Mark

    2016-01-01

    Traditionally, the Parkinson's disease (PD) symptom course has been classified as an irreversible progressive neurodegenerative disease. This paper documents 29 PD and treatment-induced systemic depletion etiologies which cause and/or exacerbate the seven novel primary relative nutritional deficiencies associated with PD. These reversible relative nutritional deficiencies (RNDs) may facilitate and accelerate irreversible progressive neurodegeneration, while other reversible RNDs may induce previously undocumented reversible pseudo-neurodegeneration that is hiding in plain sight since the symptoms are identical to the symptoms being experienced by the PD patient. Documented herein is a novel nutritional approach for reversible processes management which may slow or halt irreversible progressive neurodegenerative disease and correct reversible RNDs whose symptoms are identical to the patient's PD symptoms. PMID:27103805

  10. Reversible Cerebral Vasoconstriction Syndrome Without Typical Thunderclap Headache.

    PubMed

    Wolff, Valérie; Ducros, Anne

    2016-04-01

    Reversible cerebral vasoconstriction syndrome (RCVS) is characterized by severe headache and diffuse segmental intracranial arterial constriction that resolve within three months. Stroke, which is the major complication of RCVS, can result in persistent neurological disability, and rarely causes death. Diagnosis of RCVS early in the clinical course might improve outcomes. Although recurrent thunderclap headache is the clinical hallmark of RCVS, the absence of such a pattern should not lead to discard the diagnosis. Our literature review shows that RCVS can also manifest as an unspecific headache, such as a single severe headache episode, a mild or a progressive headache. Moreover, a subset of patients with severe RCVS presents without any headache, but frequently with seizures, focal neurological deficits, confusion or coma, in the setting of stroke or posterior reversible encephalopathy syndrome. These patients may be aphasic or in comatose state, explaining their inability to give their own medical history. They may have forgotten the headache they had a few days before more dramatic symptoms, or may have a variant of the classical RCVS. By consequence, an RCVS should be suspected in patients with any unusual headache, whether thunderclap or not, and in patients with cryptogenic stroke or convexity subarachnoid hemorrhage, whether the patient also has headache or not. Diagnosis in such cases relies on the demonstration of reversible multifocal intracranial arterial stenosis and the exclusion of other causes. PMID:27016378

  11. Reversible cerebral vasoconstriction syndrome: an under-recognized clinical emergency

    PubMed Central

    Chen, Shih-Pin; Fuh, Jong-Ling; Wang, Shuu-Jiun

    2010-01-01

    Reversible cerebral vasoconstriction syndrome (RCVS) is characterized by recurrent thunderclap headaches and reversible cerebral vasoconstrictions. RCVS is more common than previously thought and should be differentiated from aneurismal subarachnoid hemorrhage. RCVS can be spontaneous or evoked by pregnancy or exposure to vasoactive substances. Patients tend to be middle-aged women but pediatric patients have been seen. Up to 80% of sufferers have identifiable triggers. Thunderclap headaches tend to recur daily and last for a period of around 2 weeks, while the vasoconstrictions may last for months. About one-third of patients have blood pressure surges accompanying headache attacks. The potential complications of RCVS include posterior reversible encephalopathy syndrome, ischemic strokes over watershed zones, cortical subarachnoid hemorrhage and intracerebral hemorrhage. Magnetic resonance images including angiography and venography and lumbar punctures are the studies of choice, whereas catheter angiography should not be implemented routinely. Patients with a mean flow velocity of the middle cerebral artery greater than 120 cm/s shown by transcranial color-coded sonography have a greater risk of ischemic complications than those without. The pathophysiology of RCVS remains unknown; sympathetic hyperactivity may play a role. Open-label trials showed calcium channel blockers, such as nimodipine may be an effective treatment in prevention of thunderclap headache attacks. In severe cases, intra-arterial therapy may be considered. Most patients with RCVS recover without sequelae; however, relapse has been reported in a small proportion of patients. PMID:21179608

  12. Patterns of attachment of the myodural bridge by the rectus capitis posterior minor muscle.

    PubMed

    Yuan, Xiao-Ying; Yu, Sheng-Bo; Li, Yun-Fei; Chi, Yan-Yan; Zheng, Nan; Gao, Hai-Bin; Luan, Bing-Yi; Zhang, Zhao-Xi; Sui, Hong-Jin

    2016-03-01

    The myodural bridge was first described by Hack in 1995 and was thought to be related to chronic cervicogenic headaches. For a long time, few studies revealed the patterns of the myodural bridge considering the rectus capitis posterior minor muscle. In this study, P45 plastination technology and anatomical dissection were performed on head specimens, and four different terminal region types of the rectus capitis posterior minor muscle were observed, including the posterior atlanto-occipital interspace, posterior arch of the atlas and posterior atlanto-axial interspace. We propose that the myodural complex structures in the posterior atlanto-occipital and posterior atlanto-axial interspace have cooperative effects on cerebrospinal fluid and work together. This force might be an important source for the circulation of cerebrospinal fluid. PMID:25859757

  13. Lesions to right posterior parietal cortex impair visual depth perception from disparity but not motion cues.

    PubMed

    Murphy, Aidan P; Leopold, David A; Humphreys, Glyn W; Welchman, Andrew E

    2016-06-19

    The posterior parietal cortex (PPC) is understood to be active when observers perceive three-dimensional (3D) structure. However, it is not clear how central this activity is in the construction of 3D spatial representations. Here, we examine whether PPC is essential for two aspects of visual depth perception by testing patients with lesions affecting this region. First, we measured subjects' ability to discriminate depth structure in various 3D surfaces and objects using binocular disparity. Patients with lesions to right PPC (N = 3) exhibited marked perceptual deficits on these tasks, whereas those with left hemisphere lesions (N = 2) were able to reliably discriminate depth as accurately as control subjects. Second, we presented an ambiguous 3D stimulus defined by structure from motion to determine whether PPC lesions influence the rate of bistable perceptual alternations. Patients' percept durations for the 3D stimulus were generally within a normal range, although the two patients with bilateral PPC lesions showed the fastest perceptual alternation rates in our sample. Intermittent stimulus presentation reduced the reversal rate similarly across subjects. Together, the results suggest that PPC plays a causal role in both inferring and maintaining the perception of 3D structure with stereopsis supported primarily by the right hemisphere, but do not lend support to the view that PPC is a critical contributor to bistable perceptual alternations.This article is part of the themed issue 'Vision in our three-dimensional world'. PMID:27269606

  14. Illusory and veridical mapping of tactile objects in the primary somatosensory and posterior parietal cortex.

    PubMed

    Bufalari, Ilaria; Di Russo, Francesco; Aglioti, Salvatore Maria

    2014-07-01

    While several behavioral and neuroscience studies have explored visual, auditory, and cross-modal illusions, information about the phenomenology and neural correlates of somatosensory illusions is meager. By combining psychophysics and somatosensory evoked potentials, we explored in healthy humans the neural correlates of 2 compelling tactuo-proprioceptive illusions, namely Aristotle (1 object touching the contact area between 2 crossed fingers is perceived as 2 lateral objects) and Reverse illusions (2 lateral objects are perceived as 1 between crossed-fingers object). These illusions likely occur because of the tactuo-proprioceptive conflict induced by fingers being crossed in a non-natural posture. We found that different regions in the somatosensory stream exhibit different proneness to the illusions. Early electroencephalographic somatosensory activity (at 20 ms) originating in the primary somatosensory cortex (S1) reflects the phenomenal rather than the physical properties of the stimuli. Notably, later activity (around 200 ms) originating in the posterior parietal cortex is higher when subjects resist the illusions. Thus, while S1 activity is related to illusory perception, PPC acts as a conflict resolver that recodes tactile events from somatotopic to spatiotopic frames of reference and ultimately enables veridical perception. PMID:23438449

  15. Lesions to right posterior parietal cortex impair visual depth perception from disparity but not motion cues

    PubMed Central

    Leopold, David A.; Humphreys, Glyn W.; Welchman, Andrew E.

    2016-01-01

    The posterior parietal cortex (PPC) is understood to be active when observers perceive three-dimensional (3D) structure. However, it is not clear how central this activity is in the construction of 3D spatial representations. Here, we examine whether PPC is essential for two aspects of visual depth perception by testing patients with lesions affecting this region. First, we measured subjects' ability to discriminate depth structure in various 3D surfaces and objects using binocular disparity. Patients with lesions to right PPC (N = 3) exhibited marked perceptual deficits on these tasks, whereas those with left hemisphere lesions (N = 2) were able to reliably discriminate depth as accurately as control subjects. Second, we presented an ambiguous 3D stimulus defined by structure from motion to determine whether PPC lesions influence the rate of bistable perceptual alternations. Patients' percept durations for the 3D stimulus were generally within a normal range, although the two patients with bilateral PPC lesions showed the fastest perceptual alternation rates in our sample. Intermittent stimulus presentation reduced the reversal rate similarly across subjects. Together, the results suggest that PPC plays a causal role in both inferring and maintaining the perception of 3D structure with stereopsis supported primarily by the right hemisphere, but do not lend support to the view that PPC is a critical contributor to bistable perceptual alternations. This article is part of the themed issue ‘Vision in our three-dimensional world’. PMID:27269606

  16. Arm crossing updates brain functional connectivity of the left posterior parietal cortex

    PubMed Central

    Ora, Hiroki; Wada, Makoto; Salat, David; Kansaku, Kenji

    2016-01-01

    The unusual configuration of body parts can cause illusions. For example, when tactile stimuli are delivered to crossed arms a reversal of subjective temporal ordering occurs. Our group has previously demonstrated that arm crossing without sensory stimuli causes activity changes in the left posterior parietal cortex (PPC) and an assessment of tactile temporal order judgments (TOJs) revealed a positive association between activity in this area, especially the left intraparietal sulcus (IPS), and the degree of the crossed-hand illusion. Thus, the present study investigated how the IPS actively relates to other cortical areas under arms-crossed and -uncrossed conditions by analyzing the functional connectivity of the IPS. Regions showing connectivity with the IPS overlapped with regions within the default mode network (DMN) but the IPS also showed connectivity with other brain areas, including the frontoparietal control network (FPCN). The right middle/inferior frontal gyrus (MFG/IFG), which is included in the FPCN, showed greater connectivity in the arms-crossed condition than in the arms-uncrossed condition. These findings suggest that there is state-dependent connectivity during arm crossing, and that the left IPS may play an important role during the spatio-temporal updating of arm positions. PMID:27302746

  17. The Geomagnetic Field During a Reversal

    NASA Technical Reports Server (NTRS)

    Heirtzler, James R.

    2003-01-01

    By modifying the IGRF it is possible to learn what may happen to the geomagnetic field during a geomagnetic reversal. If the entire IGRF reverses then the declination and inclination only reverse when the field strength is zero. If only the dipole component of the IGRF reverses a large geomagnetic field remains when the dipole component is zero and he direction of the field at the end of the reversal is not exactly reversed from the directions at the beginning of the reversal.

  18. Reverse osmosis reverses conventional wisdom with Superfund cleanup success

    SciTech Connect

    Collins, M. ); Miller, K. )

    1994-09-01

    Although widely recognized as the most efficient means of water purification, reverse osmosis has not been considered effective for remediating hazardous wastewater. Scaling and fouling, which can cause overruns and downtime, and require membrane replacement, have inhibited success in high-volume wastewater applications. Despite this background, a reverse osmosis technology developed in Europe recently was used successfully to treat large volumes of contaminated water at a major Superfund site in Texas. The technology's success there may increase the chances for reverse osmosis to find wider use in future cleanups and other waste treatment applications.

  19. Posterior dental size reduction in hominids: the Atapuerca evidence.

    PubMed

    Bermúdez de Castro, J M; Nicolas, M E

    1995-04-01

    In order to reassess previous hypotheses concerning dental size reduction of the posterior teeth during Pleistocene human evolution, current fossil dental evidence is examined. This evidence includes the large sample of hominid teeth found in recent excavations (1984-1993) in the Sima de los Huesos Middle Pleistocene cave site of the Sierra de Atapuerca (Burgos, Spain). The lower fourth premolars and molars of the Atapuerca hominids, probably older than 300 Kyr, have dimensions similar to those of modern humans. Further, these hominids share the derived state of other features of the posterior teeth with modern humans, such as a similar relative molar size and frequent absence of the hypoconulid, thus suggesting a possible case of parallelism. We believe that dietary changes allowed size reduction of the posterior teeth during the Middle Pleistocene, and the present evidence suggests that the selective pressures that operated on the size variability of these teeth were less restrictive than what is assumed by previous models of dental reduction. Thus, the causal relationship between tooth size decrease and changes in food-preparation techniques during the Pleistocene should be reconsidered. Moreover, the present evidence indicates that the differential reduction of the molars cannot be explained in terms of restriction of available growth space. The molar crown area measurements of a modern human sample were also investigated. The results of this study, as well as previous similar analyses, suggest that a decrease of the rate of cell proliferation, which affected the later-forming crown regions to a greater extent, may be the biological process responsible for the general and differential dental size reduction that occurred during human evolution. PMID:7604890

  20. Minimal incision posterior approach levator plication for aponeurotic ptosis

    PubMed Central

    Ng, D S; Chan, E; Ko, S T

    2015-01-01

    Purpose To assess the efficacy and predictability of a minimal incision posterior approach levator plication technique for correction of involutional ptosis. Method Retrospective chart review of patients with involutional aponeurotic ptosis underwent minimal incision posterior approach levator plication technique between August 2013 and June 2014 by a single surgeon. The upper lid was double everted, and the conjunctiva and Muller's muscle layers were incised vertically until the levator aponeurosis could be identified. The incision(s) was similar to performing incision and curettage of chalazion, except that the site was above the tarsal plate and extended towards the fornix. Then insertion of aponeurosis was dissected away from the anterior tarsal surface, and the more superiorly located levator was plicated on it with double arm suture(s). No tissue was excised in this procedure. Surgical success was defined as a postoperative margin reflex distance (MRD)>2 mm and<4.5 mm, interlid height<1 mm and satisfactory contour. Results Forty-four lids of 27 patients were included. Preoperative mean MRD was 0.48 +/− 0.56 mm. Severe ptosis of MRD<1 mm was present in 34/44 patients (77.3%). The postoperative mean MRD was 2.49 +/− 0.53 mm, and mean improvement was 2.02 +/− 0.61 mm, which was statistically significant (P<0.001). The overall success rate was 38/44 (86.4%). Conclusions Minimal incision posterior approach to levator plication was effective for the correction of aponeurotic ptosis with moderate to good levator function. PMID:25613849

  1. Posterior dynamic stabilization: The interspinous spacer from treatment to prevention

    PubMed Central

    Nachanakian, Antoine; El Helou, Antonios; Alaywan, Moussa

    2016-01-01

    Introduction: Managements of lumbar stenosis evoluted over the time from decompression to dynamic stabilization preserving the motion segment passing by the rigid fixation. After long years of rigid fusion, adjacent segment disease became more and more frequent and the concept of dynamic stabilization emerged. Materials and Methods: We report our experience with posterior dynamic stabilization using an interspinous distracter (ISD). One hundred and eight patients were operated between September 2008 and January 2012 with different lumbar spine pathologies. The ages of our patients were between 45 years and 70 years, with a mean age of 55 years. With our growing experience, indication of ISD became narrowed and the interspinous spacer became an absolute tool for adjacent segment disease as a treatment as well as prophylactic with rigid stabilization. Results and Discussion: Overall clinical improvement was noted in ISD-treated patients, with considerable satisfaction in 77% of patients on average. The patient at first reported an improvement of their radicular pain with a mean reduction of 3.6/10 on visual analog scale. Post-operative walking distance progressively increased during the next 3 months. Whereas, a radiological evaluation at 3 months showed a mean of 42% improvement of the disc height. On the other hand, all patients operated with posterior dynamic stabilization (PDS) at the time of rigid stabilization showed no adjacent segment disease compared to those operated with posterior arthrodesis (P < 0.05). Conclusion: Interspinous spacer after surgical decompression for spinal stenosis by excision of Ligamentum flavum demonstrates excellent short-term and long-term results for improvement in back pain, neurogenic claudication, and patient satisfaction. It provides restoration of disc height, reduction of vertebral slip and it's a necessary tool in the management and the prevention of adjacent segment disease. PMID:27057211

  2. Heterogeneous and nonlinear development of human posterior parietal cortex function.

    PubMed

    Chang, Ting-Ting; Metcalfe, Arron W S; Padmanabhan, Aarthi; Chen, Tianwen; Menon, Vinod

    2016-02-01

    Human cognitive problem solving skills undergo complex experience-dependent changes from childhood to adulthood, yet most neurodevelopmental research has focused on linear changes with age. Here we challenge this limited view, and investigate spatially heterogeneous and nonlinear neurodevelopmental profiles between childhood, adolescence, and young adulthood, focusing on three cytoarchitectonically distinct posterior parietal cortex (PPC) regions implicated in numerical problem solving: intraparietal sulcus (IPS), angular gyrus (AG), and supramarginal gyrus (SMG). Adolescents demonstrated better behavioral performance relative to children, but their performance was equivalent to that of adults. However, all three groups differed significantly in their profile of activation and connectivity across the PPC subdivisions. Activation in bilateral ventral IPS subdivision IPS-hIP1, along with adjoining anterior AG subdivision, AG-PGa, and the posterior SMG subdivision, SMG-PFm, increased linearly with age, whereas the posterior AG subdivision, AG-PGp, was equally deactivated in all three groups. In contrast, the left anterior SMG subdivision, SMG-PF, showed an inverted U-shaped profile across age groups such that adolescents exhibited greater activation than both children and young adults. Critically, greater SMG-PF activation was correlated with task performance only in adolescents. Furthermore, adolescents showed greater task-related functional connectivity of the SMG-PF with ventro-temporal, anterior temporal and prefrontal cortices, relative to both children and adults. These results suggest that nonlinear up-regulation of SMG-PF and its interconnected functional circuits facilitate adult-level performance in adolescents. Our study provides novel insights into heterogeneous age-related maturation of the PPC underlying cognitive skill acquisition, and further demonstrates how anatomically precise analysis of both linear and nonlinear neurofunctional changes with age is

  3. Endophthalmitis following Nd:YAG laser posterior capsulotomy.

    PubMed

    Carlson, A N; Koch, D D

    1988-03-01

    We report the development of Propionibacterium acnes endophthalmitis following Nd:YAG laser posterior capsulotomy. The patient previously underwent uncomplicated extracapsular cataract extraction with intraocular lens insertion and was free of inflammation prior to laser capsulotomy. Diagnostic vitrectomy and aqueous tap were performed, and P. acnes was isolated from the aqueous in thiol broth media after nine days of incubation under anaerobic conditions. The patient was managed with topical and systemic antibiotics and steroids. Complete resolution of inflammation with return of vision to 20/25 was achieved without removal of the intraocular lens or lenticular remnants. PMID:3258419

  4. [Ischemic insult in the anterior and posterior cerebral circulation].

    PubMed

    Smajlović, Dzevdet; Ibrahimagić, Omer; Dostović, Zikrija

    2003-01-01

    In the everyday practice among clinical and etiological classifications for ischemic stroke, the terms strokes in the anterior and posterior cerebral circulation are also in use. The aim of this study was to analyze the frequency of ischemic strokes in the anterior and posterior circulation, their age and sex distribution, risk factors and hospital mortality. In the study it was analyzed 1772 patients with acute ischemic stroke hospitalized at the Department of Neurology Tuzla, Bosnia and Herzegovina, between January 1st 1996 and December 31st 2000. The mean age was 65.5 years (+9.9), 942 (55%) were females. Ischemic strokes for all patients were confirmed with computed tomography, while other data were collected from the standard patients' history charts. Anterior circulation stroke (ACS) had 1408 patients (81.8%), the rest of 314 (18.2%) had posterior circulation stroke (PCS). In the both types females were slightly overrepresented: 784 (56%) in ACS, and 158 (50.5%) in PCS. Moreover, females were significantly older than males: 67 (+9.8) versus 64 (+10) years in ACS (p < 0.001), 67.5 (+10.3) versus 63.5 (+9.2) in PCS (p < 0.001). Hypertension was the major risk factor occurring in 67% patients with ACS and 71 with PCS; heart diseases 54% in the both types, and diabetes in 23% patients with ACS and 20% with PCS. The cortical ischemic lesion was verified in 46% patients with ACS, 41% with PCS; subcortical in 12.5% and 14.5%; and lacunar in 41.5% and 44.5%, respectively. Hospital mortality was 30% (430 patients) for ACS, and 32% (101 patients) for PCS. Hospital mortality was considerably higher among females: 33% versus 28% for ACS (p = 0.03), 38% versus 27% for PCS (p = 0.03). On the basis of our study we can conclude that ischemic strokes in the anterior cerebral circulation are 4/5 of all ischemic strokes at the Department of Neurology Tuzla. Both, anterior and posterior circulation strokes are more frequent in females, witches were in average older than males

  5. Isolated posterior malleolus fracture: a rare injury mechanism

    PubMed Central

    Serbest, Sancar; Tiftikçi, Uğur; Tosun, Haci Bayram; Kesgin, Engin; Karataş, Metin

    2015-01-01

    Sprain of the ankle is undoubtedly a common injury during athletic activity, and the sprain can be also associated with fracture of the ankle. Isolated posterior malleolus fracture is a very rare condition, which is usually missed. Here, we are presenting a 37 years old female patient, who suffered injury secondary pressing on brake pedal during collision in a traffic accident. Clinical evaluation is based on Ottawa Ankle Rules and a fracture is diagnosed; patient is started on daily activities at postoperative Week 8. This study aims to emphasize that Ottawa Ankle Rules are usually efficient for evaluating fractures of ankle, but clinicians should always make a detailed physical examination. PMID:26097627

  6. Reconstructive Options for Oncologic Posterior Trunk Defects: A Review

    PubMed Central

    Behr, Björn; Wagner, Johannes M.; Wallner, Christoph; Harati, Kamran; Lehnhardt, Marcus; Daigeler, Adrien

    2016-01-01

    After oncological tumor resections at the back, large defects can remain that depending on the size and location may represent reconstructive challenges to plastic surgeons. Flap selection includes the entire armamentarium of coverage, including transposition flaps, perforator flaps, pedicled muscle flaps, and free flaps. Most defects can be closed and reconstructed with local or pedicled muscle flaps. In our hands, sufficient closure could be obtained with all techniques, except the latissimus dorsi turn-over flap. Thereupon, an algorithm for closure of posterior trunk defects related to the anatomical region is proposed. PMID:27014626

  7. Echocardiographic Manifestation of Esophagitis Mimicking a Posterior Mediastinal Mass

    PubMed Central

    Swarup, Supreeya; Kantamneni, Sowmya; Kabir, Sarah; Zeltser, Roman; Makaryus, Amgad N

    2014-01-01

    Incidental extracardiac findings (ECFs) are commonly noted on cardiac imaging. The majority of the ECFs are noticed on computed tomography (CT), cardiac magnetic resonance scanning, and myocardial perfusion imaging. Although transthoracic echocardiography (TTE) is a widely used cardiac modality, there is scarcity of data describing ECF on TTE. ECFs have the potential to alter patient management. We present a rare case of a cystic mass seen in the posterior mediastinum on TTE, which led to further evaluation and diagnosis of esophagitis with ulceration. PMID:25780343

  8. Clipping of ipsilateral posterior communicating and superior cerebellar artery aneurysms.

    PubMed

    Welch, Babu G

    2015-01-01

    The case is a 55-year-old female who presented with dizziness as the chief complaint. She has a family history of two relatives with subarachnoid hemorrhage. Digital subtraction angiography revealed the presence of a left-sided posterior communicating artery aneurysm and an ipsilateral superior cerebellar artery (SCA) aneurysm. Due to the smaller nature of the SCA, a decision was made to proceed with surgical clipping of both lesions through a pterional approach. A narrated video with illustrations depicts the intraoperative management of these lesions with postoperative angiography results. The video can be found here: http://youtu.be/HCHToSsXv-4 . PMID:25554845

  9. Endovascular coil embolization of unruptured posterior communicating artery aneurysm.

    PubMed

    Binning, Mandy; Hakma, Zakaria; Veznedaroglu, Erol

    2014-07-01

    The patient is a 60-year-old woman who presented to her primary care physician with new onset of headache. She was neurologically intact without cranial nerve deficit. An outpatient CT angiogram (CTA) revealed no subarachnoid hemorrhage, but showed a right-sided posterior communicating artery aneurysm measuring 11 mm by 10 mm. Digitally subtracted cerebral angiography confirmed these measurements and showed that the aneurysm was amenable to endovascular coil embolization. The patient underwent aneurysm coiling without complication and was discharged to home on postoperative Day 1. The video can be found here: http://youtu.be/MjOc3Zpv2K8 . PMID:24983726

  10. Neuralgic Amyotrophy Manifesting as Mimicking Posterior Interosseous Nerve Palsy.

    PubMed

    Yang, Jin Seo; Cho, Yong Jun; Kang, Suk Hyung; Choi, Eun Hi

    2015-11-01

    The upper trunk of the brachial plexus is the most common area affected by neuralgic amyotrophy (NA), and paresis of the shoulder girdle muscle is the most prevalent manifestation. Posterior interosseous nerve palsy is a rare presentation in patients with NA. It results in dropped finger on the affected side and may be misdiagnosed as entrapment syndrome or compressive neuropathy. We report an unusual case of NA manifested as PIN palsy and suggest that knowledge of clinical NA phenotypes is crucial for early diagnosis of peripheral nerve palsies. PMID:26713154

  11. Consolidation of Complex Events via Reinstatement in Posterior Cingulate Cortex

    PubMed Central

    Keidel, James L.; Ing, Leslie P.; Horner, Aidan J.

    2015-01-01

    It is well-established that active rehearsal increases the efficacy of memory consolidation. It is also known that complex events are interpreted with reference to prior knowledge. However, comparatively little attention has been given to the neural underpinnings of these effects. In healthy adults humans, we investigated the impact of effortful, active rehearsal on memory for events by showing people several short video clips and then asking them to recall these clips, either aloud (Experiment 1) or silently while in an MRI scanner (Experiment 2). In both experiments, actively rehearsed clips were remembered in far greater detail than unrehearsed clips when tested a week later. In Experiment 1, highly similar descriptions of events were produced across retrieval trials, suggesting a degree of semanticization of the memories had taken place. In Experiment 2, spatial patterns of BOLD signal in medial temporal and posterior midline regions were correlated when encoding and rehearsing the same video. Moreover, the strength of this correlation in the posterior cingulate predicted the amount of information subsequently recalled. This is likely to reflect a strengthening of the representation of the video's content. We argue that these representations combine both new episodic information and stored semantic knowledge (or “schemas”). We therefore suggest that posterior midline structures aid consolidation by reinstating and strengthening the associations between episodic details and more generic schematic information. This leads to the creation of coherent memory representations of lifelike, complex events that are resistant to forgetting, but somewhat inflexible and semantic-like in nature. SIGNIFICANCE STATEMENT Memories are strengthened via consolidation. We investigated memory for lifelike events using video clips and showed that rehearsing their content dramatically boosts memory consolidation. Using MRI scanning, we measured patterns of brain activity while

  12. Neurothekeoma in the Posterior Fossa: Case Report and Literature Review

    PubMed Central

    Alexandru, Daniela; Satyadev, Radha; So, William

    2012-01-01

    Neurothekeoma is a benign nerve sheath tumor, also known as nerve sheath myxoma. It arises from the cutaneous nerves of the head and neck region. In certain cases, neurothekeoma has been reported in the breast, oral cavity, tongue, maxilla, and spinal intradural space. Intracranial neurothekeoma, however, is an extremely rare entity, with only three cases reported in the literature: one in the parasellar region, one in the deep white matter, and another one in the cerebellopontine angle. We present the case of a 40-year-old man with a very large neurothekeoma present in the posterior fossa who had no neurologic deficit on presentation. PMID:23012602

  13. A Massive Posterior Neck Mass: Lipoma or Something More Sinister?

    PubMed Central

    Ryan, Matthew F.

    2013-01-01

    Lipomas are slow-growing benign soft-tissue tumors which are typically asymptomatic and occur in approximately 1% of the population. A lipoma is considered to be of excessive size when it is greater than 10 cm in length (in any dimension) or weighs over 1000 g (Kransdorf (1995)). We describe a case of a man presenting with a giant posterior neck mass which greatly reduced the sagittal range of cervical spine. A discussion of the pathophysiology of lipomas and a literature review regarding giant lipomas versus malignancy follows. PMID:24223314

  14. Complications of Anterior and Posterior Cervical Spine Surgery

    PubMed Central

    Cheung, Jason Pui Yin

    2016-01-01

    Cervical spine surgery performed for the correct indications yields good results. However, surgeons need to be mindful of the many possible pitfalls. Complications may occur starting from the anaesthestic procedure and patient positioning to dura exposure and instrumentation. This review examines specific complications related to anterior and posterior cervical spine surgery, discusses their causes and considers methods to prevent or treat them. In general, avoiding complications is best achieved with meticulous preoperative analysis of the pathology, good patient selection for a specific procedure and careful execution of the surgery. Cervical spine surgery is usually effective in treating most pathologies and only a reasonable complication rate exists. PMID:27114784

  15. Posterior dislocation of the sternoclavicular joint leading to mediastinal compression.

    PubMed

    Jougon, J B; Lepront, D J; Dromer, C E

    1996-02-01

    Dislocations of the sternoclavicular joint are uncommon, and the posterior variety have a potential for considerable morbidity. We report a case with compression of the vital structures within the superior mediastinum. It was a rugby player getting run over by the scrum. The mechanism was an indirect force exerted forward and laterally against the shoulder. The patient complained of pain and dysphagia. A systolic right cervical murmur was heard. Angiography was normal and esophagography showed extrinsic esophageal compression. Surgical reduction was performed because there was a slight pneumomediastinum on the computed tomography. This case report demonstrates the mechanism, complications, and treatment of such a lesion. PMID:8572795

  16. Simple posterior frequency correction for vibrational spectra from molecular dynamics

    NASA Astrophysics Data System (ADS)

    Tikhonov, Denis S.

    2016-05-01

    Vibrational spectra computed from molecular dynamics simulations with large integration time steps suffer from nonphysical frequency shifts of signals [M. Praprotnik and D. Janežič, J. Chem. Phys. 122, 174103 (2005)]. A simple posterior correction technique was developed for compensation of this behavior. It performs through replacement of abscissa in the calculated spectra using following formula: ν corrected = /√{ 2 ṡ (" separators=" 1 - cos ( 2 π ṡ Δ t ṡ ν initial ) ) } 2 π ṡ Δ t , where ν are initial and corrected frequencies and Δt is the MD simulation time step. Applicability of this method was tested on gaseous infrared spectra of hydrogen fluoride and formic acid.

  17. Application of sonography for evaluation of posterior circulation disorders.

    PubMed

    Alpaidze, M; Janelidze, M

    2014-03-01

    Posterior circulation disorders (PCD) include a) vertebrobasilar insufficiency (VBI), which has a wide clinical manifestation such as vestibulocerebellar syndrome, cephalalgia, cochlear syndrome, vegetovascular dystonia, visual disturbances, "syndrome of vertebral artery compression" etc, b) vertebrobasilar TIA and c) stroke. All of them are caused by blood flow disturbances in vertebral (VA), basilar (BAS) and posterior cerebral arteries (PCA). Aim - evaluation of role of extracranial duplex-sonography (EDS), transcranial color-coded duplex-sonography (TCCD) and rotational functional tests (RFT) in PCD. 88 patients (age range 18-62y) with PCD and 20 healthy controls with relevant age range were examined using EDS, TCCD and RFT with measurement of vertebral arteries (VA) diameter, mean flow velocities (MFV) and pulsatility index (PI) in VA, basilar artery (BAS) and posterior cerebral arteries (PCA). For statistical analysis SPSS software (Version 11.5) was used. In 48 (54,5%) patients revealed unilateral narrowing (less than 2.5 mm in diameter) and deformation of vertebral artery associated with osteochondrosis or primary hypoplasia. In 11 (12,5%) patients revealed bilateral narrowing (less than 2.8 mm in diameter) and deformation of vertebral arteries. Ultrasound investigation showed a decrease of MFV (23 ± 1.4 cm/sec) in the intracranial length of vertebral artery and an increase of PI (3,2 ±0,3 p=0,002) in the extracranial segments (V1- V3). In 52 cases (59%) revealed decrease of MFV in BAS by 32.6 ± 4.7% and in 41 cases (46.5%) decrease of MFV in both PCA by 24.8 ± 5.2% (P<0.002). In 21 cases (23.8%) revealed concurrent development of vertebrogenic reflex vasoconstriction. In 18 patients (20.4%) exposed only deformation of vertebral arteries with local increase of MFV and normal values in intracranial segments. Rotational tests were positive in 42 (47.7%) patients and manifested high correlation with clinical data. EDS and TCCD are important tools for

  18. Foraminotomia cervical posterior en el tratamiento de conflictos foraminales

    PubMed Central

    Campero, Álvaro; Barrera, Ramiro; Ajler, Pablo

    2012-01-01

    Introducción: La foraminomotima cervical posterior es un procedimiento utilizado para la descompresion radicular por via posterior y constituye una alternativa a la via clásica anterior. En este trabajo evaluamos nuestra serie de pacientes tratados por esta via. Método: Desde enero de 2008 a diciembre de 2011, 17 pacientes (18 foraminotomías) fueron operados por presentar cervicobraquialgia a causa de un conflicto foraminal, realizando un foraminotomía cervical posterior. Los pacientes fueron evaluados en el postoperatorio inmediato, al mes y a los 3 meses de la cirugía. Los parámetros para valorar los resultados fueron la Escala Análoga del Dolor (VAS), la Neck Disability Index y los criterios de Odom. Resultados: El dolor radicular por conflicto foraminal secundario a hernia de disco cervical fue el síntoma y la patología predominante. El nivel más afectado fue C5-C6. La resolución completa del dolor radicular se observó en casi todos los pacientes. La VAS preoperatoria en promedio fue de 8.8 (mínimo 8 – máximo 10), con una franca mejoría en todos los casos (0.4 en el último control). La media en la Neck Disability Index al inicio fue de 35.3 (mínimo 32 – máximo 45), con una evolución favorable en la evaluación final (0.6). Los Criterios de Odom para la evaluación de pacientes operados de columna cervical fueron satisfactorios con un promedio de 1.17. Se observaron complicaciones en 4 pacientes (23%), todas tuvieron una evolución favorable. No hubo infecciones, discitis ni empeoramiento de los síntomas preexistentes en ningún paciente. Conclusión: La foraminotomía cervical posterior es un procedimiento efectivo para el tratamiento del dolor radicular en los conflictos foraminales PMID:23596556

  19. Considerations for ceramic inlays in posterior teeth: a review

    PubMed Central

    Hopp, Christa D; Land, Martin F

    2013-01-01

    This review of ceramic inlays in posterior teeth includes a review of the history of ceramic restorations, followed by common indications and contraindications for their use. A discussion on the potential for tooth wear is followed by a review of recommended preparation design considerations, fabrication methods, and material choices. Despite the improved materials available for fabrication of porcelain inlays, fracture remains a primary mode of inlay failure. Therefore, a brief discussion on strengthening methods for ceramics is included. The review concludes with a section on luting considerations, and offers the clinician specific recommendations for luting procedures. In conclusion, inlay success rates and longevity, as reported in the literature, are summarized. PMID:23750101

  20. Typical trigeminal neuralgia associated with posterior cranial fossa tumors.

    PubMed

    Puca, A; Meglio, M

    1993-10-01

    A clinical diagnosis of typical trigeminal neuralgia does not rule out the possibility of a space-occupying lesion compressing the nerve along its course from the brainstem to Meckel's cave. 4 cases of typical trigeminal neuralgia, treated medically for several years and seen here recently before a space-occupying lesion was found in the posterior cranial fossa, point up the need for thorough neurological and neuroradiological examination of all patients with the typical symptoms. Lesion removal resulted in total relief from pain in 3 patients. In the fourth patient the pain was controlled by percutaneous surgery with thermocoagulation of the gasserian ganglion. PMID:8282526

  1. Isolated posterior malleolus fracture: a rare injury mechanism.

    PubMed

    Serbest, Sancar; Tiftikçi, Uğur; Tosun, Haci Bayram; Kesgin, Engin; Karataş, Metin

    2015-01-01

    Sprain of the ankle is undoubtedly a common injury during athletic activity, and the sprain can be also associated with fracture of the ankle. Isolated posterior malleolus fracture is a very rare condition, which is usually missed. Here, we are presenting a 37 years old female patient, who suffered injury secondary pressing on brake pedal during collision in a traffic accident. Clinical evaluation is based on Ottawa Ankle Rules and a fracture is diagnosed; patient is started on daily activities at postoperative Week 8. This study aims to emphasize that Ottawa Ankle Rules are usually efficient for evaluating fractures of ankle, but clinicians should always make a detailed physical examination. PMID:26097627

  2. Arthroscopic Management of Anterior, Posterior, and Multidirectional Shoulder Instabilities.

    PubMed

    Field, Larry D; Ryu, Richard K N; Abrams, Jeffrey S; Provencher, Matthew

    2016-01-01

    Arthroscopic shoulder stabilization offers several potential advantages compared with open surgery, including the opportunity to more accurately evaluate the glenohumeral joint at the time of diagnostic assessment; comprehensively address multiple pathologic lesions that may be identified; and avoid potential complications unique to open stabilization, such as postoperative subscapularis failure. A thorough understanding of normal shoulder anatomy and biomechanics, along with the pathoanatomy responsible for anterior, posterior, and multidirectional shoulder instability patterns, is very important in the management of patients who have shoulder instability. The treating physician also must be familiar with diagnostic imaging and physical examination maneuvers that are required to accurately diagnose shoulder instability. PMID:27049209

  3. Current approach in the diagnosis and management of posterior uveitis

    PubMed Central

    Sudharshan, S; Ganesh, Sudha K; Biswas, Jyotrimay

    2010-01-01

    Posterior uveitic entities are varied entities that are infective or non-infective in etiology. They can affect the adjacent structures such as the retina, vitreous, optic nerve head and retinal blood vessels. Thorough clinical evaluation gives a clue to the diagnosis while ancillary investigations and laboratory tests assist in confirming the diagnosis. Newer evolving techniques in the investigations and management have increased the diagnostic yield. In case of diagnostic dilemma, intraocular fluid evaluation for polymerase chain testing for the genome and antibody testing against the causative agent provide greater diagnostic ability. PMID:20029144

  4. How decision reversibility affects motivation.

    PubMed

    Bullens, Lottie; van Harreveld, Frenk; Förster, Jens; Higgins, Tory E

    2014-04-01

    The present research examined how decision reversibility can affect motivation. On the basis of extant findings, it was suggested that 1 way it could affect motivation would be to strengthen different regulatory foci, with reversible decision making, compared to irreversible decision making, strengthening prevention-related motivation relatively more than promotion-related motivation. If so, then decision reversibility should have effects associated with the relative differences between prevention and promotion motivation. In 5 studies, we manipulated the reversibility of a decision and used different indicators of regulatory focus motivation to test these predictions. Specifically, Study 1 tested for differences in participants' preference for approach versus avoidance strategies toward a desired end state. In Study 2, we used speed and accuracy performance as indicators of participants' regulatory motivation, and in Study 3, we measured global versus local reaction time performance. In Study 4, we approached the research question in a different way, making use of the value-from-fit hypothesis (Higgins, 2000, 2002). We tested whether a fit between chronic regulatory focus and focus induced by the reversibility of the decision increased participants' subjective positive feelings about the decision outcome. Finally, in Study 5, we tested whether regulatory motivation, induced by decision reversibility, also influenced participants' preference in specific product features. The results generally support our hypothesis showing that, compared to irreversible decisions, reversible decisions strengthen a prevention focus more than a promotion focus. Implications for research on decision making are discussed. PMID:23815456

  5. Ipsilateral Traumatic Posterior Hip Dislocation, Posterior Wall and Transverse Acetabular Fracture with Trochanteric Fracture in an adult: Report of First Case

    PubMed Central

    Sinha, Skand; Naik, Ananta k; Arya, Rajendra K; Jain, Vijay K

    2013-01-01

    Introduction: Posterior dislocation of the hip joint with associated acetabular and intertrochanteric fracture is a complex injury. Early recognition, prompt and stable reduction is needed of successful outcome. Case Report: 45 year old male patient presented with posterior dislocation of the hip with transverse fracture with posterior wall fracture of acetabulam and intertrochanteric fracture on the ipsilateral side. The complex fracture geometry was confirmed by CT scan. The patient was successfully managed by open reduction and internal fixation of intertrochanteric fracture was achieved with dynamic hip screw (DHS) plate fixation followed by fixation of acetabular fracture with reconstruction plate. Conclusion: Hip dislocation combined with acetabular fracture is an uncommon injury; this article presents a unique case of posterior wall and transverse fractures of ipsilateral acetabulum with intertrochanteric fracture in a patient who sustained traumatic posterior hip dislocation. Early surgical intervention is important for satisfactory outcomes of such complex fracture-dislocation injuries. PMID:27298928

  6. Supercritical fluid reverse micelle separation

    DOEpatents

    Fulton, J.L.; Smith, R.D.

    1993-11-30

    A method of separating solute material from a polar fluid in a first polar fluid phase is provided. The method comprises combining a polar fluid, a second fluid that is a gas at standard temperature and pressure and has a critical density, and a surfactant. The solute material is dissolved in the polar fluid to define the first polar fluid phase. The combined polar and second fluids, surfactant, and solute material dissolved in the polar fluid is maintained under near critical or supercritical temperature and pressure conditions such that the density of the second fluid exceeds the critical density thereof. In this way, a reverse micelle system defining a reverse micelle solvent is formed which comprises a continuous phase in the second fluid and a plurality of reverse micelles dispersed in the continuous phase. The solute material is dissolved in the polar fluid and is in chemical equilibrium with the reverse micelles. The first polar fluid phase and the continuous phase are immiscible. The reverse micelles each comprise a dynamic aggregate of surfactant molecules surrounding a core of the polar fluid. The reverse micelle solvent has a polar fluid-to-surfactant molar ratio W, which can vary over a range having a maximum ratio W[sub o] that determines the maximum size of the reverse micelles. The maximum ratio W[sub o] of the reverse micelle solvent is then varied, and the solute material from the first polar fluid phase is transported into the reverse micelles in the continuous phase at an extraction efficiency determined by the critical or supercritical conditions. 27 figures.

  7. Supercritical fluid reverse micelle separation

    DOEpatents

    Fulton, John L.; Smith, Richard D.

    1993-01-01

    A method of separating solute material from a polar fluid in a first polar fluid phase is provided. The method comprises combining a polar fluid, a second fluid that is a gas at standard temperature and pressure and has a critical density, and a surfactant. The solute material is dissolved in the polar fluid to define the first polar fluid phase. The combined polar and second fluids, surfactant, and solute material dissolved in the polar fluid is maintained under near critical or supercritical temperature and pressure conditions such that the density of the second fluid exceeds the critical density thereof. In this way, a reverse micelle system defining a reverse micelle solvent is formed which comprises a continuous phase in the second fluid and a plurality of reverse micelles dispersed in the continuous phase. The solute material is dissolved in the polar fluid and is in chemical equilibrium with the reverse micelles. The first polar fluid phase and the continuous phase are immiscible. The reverse micelles each comprise a dynamic aggregate of surfactant molecules surrounding a core of the polar fluid. The reverse micelle solvent has a polar fluid-to-surfactant molar ratio W, which can vary over a range having a maximum ratio W.sub.o that determines the maximum size of the reverse micelles. The maximum ratio W.sub.o of the reverse micelle solvent is then varied, and the solute material from the first polar fluid phase is transported into the reverse micelles in the continuous phase at an extraction efficiency determined by the critical or supercritical conditions.

  8. Molecularly Regulated Reversible DNA Polymerization.

    PubMed

    Chen, Niancao; Shi, Xuechen; Wang, Yong

    2016-06-01

    Natural polymers are synthesized and decomposed under physiological conditions. However, it is challenging to develop synthetic polymers whose formation and reversibility can be both controlled under physiological conditions. Here we show that both linear and branched DNA polymers can be synthesized via molecular hybridization in aqueous solutions, on the particle surface, and in the extracellular matrix (ECM) without the involvement of any harsh conditions. More importantly, these polymers can be effectively reversed to dissociate under the control of molecular triggers. Since nucleic acids can be conjugated with various molecules or materials, we anticipate that molecularly regulated reversible DNA polymerization holds potential for broad biological and biomedical applications. PMID:27100911

  9. Ferroelectric polarization reversal in single crystals

    NASA Technical Reports Server (NTRS)

    Stadler, Henry L.

    1992-01-01

    Research on the reversal of polarization in ferroelectric crystals is reviewed. Particular attention is given to observation methods for polarization reversal, BaTiO3 polarization reversal, crystal thickness dependence of polarization reversal, and domain wall movement during polarization reversal in TGS.

  10. Epicardial mapping of ventricular fibrillation over the posterior descending artery and left posterior papillary muscle of the swine heart

    PubMed Central

    Nielsen, Thomas D.; Huang, Jian; Rogers, Jack M.; Killingsworth, Cheryl R.

    2008-01-01

    Background Recent studies suggest that during ventricular fibrillation (VF) epicardial vessels may be a site of conduction block and the posterior papillary muscle (PPM) in the left ventricle (LV) may be the location of a “mother rotor.” The goal of this study was to obtain evidence to support or refute these possibilities. Methods Epicardial activation over the posterior LV and right ventricle (RV) was mapped during the first 20 s of electrically induced VF in six open-chest pigs with a 504 electrode plaque covering a 20 cm2 area centered over the posterior descending artery (PDA). Results The locations of epicardial breakthrough as well as reentry clustered in time and space during VF. Spatially, reentry occurred significantly more frequently over the LV than the RV in all 48 episodes, and breakthrough clustered near the PPM (p<0.001). Significant temporal clustering occurred in 79% of breakthrough episodes and 100% of reentry episodes. These temporal clusters occurred at different times so that there was significantly less breakthrough when reentry was present (p<0.0001). Conduction block occurred significantly more frequently near the PDA than elsewhere. Conclusions The PDA is a site of epicardial block which may contribute to VF maintenance. Epicardial breakthrough clusters near the PPM. Reentry also clusters in space but at a separate site. The fact that breakthrough and reentry cluster at different locations and at different times supports the possibility of a drifting filament at the PPM so that at times reentry is present on the surface but at other times the reentrant wavefront breaks through to the epicardium. PMID:18839296

  11. Improving reversal median computation using commuting reversals and cycle information.

    PubMed

    Arndt, William; Tang, Jijun

    2008-10-01

    In the past decade, genome rearrangements have attracted increasing attention from both biologists and computer scientists as a new type of data for phylogenetic analysis. Methods for reconstructing phylogeny from genome rearrangements include distance-based methods, MCMC methods, and direct optimization methods. The latter, pioneered by Sankoff and extended with the software suites GRAPPA and MGR, is the most accurate approach, but is very limited due to the difficulty of its scoring procedure--it must solve multiple instances of the reversal median problem to compute the score of a given tree. The reversal median problem is known to be NP-hard and all existing solvers are extremely slow when the genomes are distant. In this paper, we present a new reversal median heuristic for unichromosomal genomes. The new method works by applying sets of reversals in a batch where all such reversals both commute and do not break the cycle of any other. Our testing using simulated datasets shows that this method is much faster than the leading solver for difficult datasets with only a slight accuracy penalty, yet retains better accuracy than other heuristics with comparable speed, and provides the additional option of searching for multiple medians. This method dramatically increases the speed of current direct optimization methods and enables us to extend the range of their applicability to organellar and small nuclear genomes with more than 50 reversals along each edge. PMID:18774904

  12. Posterior Urethral Valves: Renal Failure and Prenatal Treatment

    PubMed Central

    Casella, Daniel P.; Tomaszewski, Jeffrey J.; Ost, Michael C.

    2012-01-01

    Posterior urethral valves occur in 1 : 5000 live births. Despite the high prevalence, the few children that survive do poorly, with over 50% progressing to ESRD in 10 years. The gold standard for post-natal diagnosis is voiding cystourethrography, while pre-natal diagnosis is dependent on routine screening ultrasonography. Despite the ability to identify features of bladder outlet obstruction early in fetal development, there is no consensus on how to incorporate early detection into current screening protocols. There has yet to be a marker that allows prediction of obstruction in the absence of or prior to radiographic evidence of obstruction. With our current screening strategy, the majority of interventions are performed well after irreversible damage has occurred. Improved mortality and long term morbidity from posterior urethral valves and congenital bladder outlet obstruction will likely remain unchanged until it is possible to intervene prior to the onset of irreversible renal damage. New biologic markers and improved instrumentation will allow for more effective diagnosis and intervention at earlier stages of fetal development. PMID:21860792

  13. Advances in Drug Delivery to the Posterior Segment

    PubMed Central

    Pearce, William; Hsu, Jason; Yeh, Steven

    2015-01-01

    Purpose Emerging developments and research for drug delivery to the posterior segment offer a promising future for the treatment of vitreoretinal disease. As new technologies enter the market, clinicians should be aware of new indications and ongoing clinical trials. Recent Findings This review summarizes the advantages and shortcomings of the most commonly used drug delivery methods including vitreous dynamics, physician sustainability and patient preferences. Currently available intravitreal corticosteroid-release devices offer surgical and in-office management of retinal vascular disease and posterior uveitis. The suprachoroidal space offers a new anatomic location for the delivery of lower dose medications directly to the target tissue. Implantable drug reservoirs would potentially allow for less frequent intravitreal injections reducing treatment burdens and associated risks. Newer innovations in encapsulated cell technology offer promising results in early clinical trials. Summary While pars plana intravitreal injection remains the mainstay of therapy for many vitreoretinal diseases, targeted delivery and implantable eluting devices are rapidly demonstrating safety and efficacy. These therapeutic modalities offer promising options for the vitreoretinal therapeutic landscape. PMID:25759965

  14. Posterior epidural fibrotic mass associated with Baastrup’s disease

    PubMed Central

    Jang, Eui-Chan; Lee, Han-Jun; Kim, Jae Yoon; Yang, Jae Jun

    2010-01-01

    A few reports have demonstrated rare cases of Baastrup’s disease that involve epidural cysts that cause dural compression. However, there have been no reports of a midline epidural fibrotic mass being associated with Baastrup’s disease. A 60-year-old man presented with neurogenic claudication that had lasted for 5 years. Radiography showed anterolisthesis at the L4–L5 level, magnetic resonance imaging demonstrated severe stenosis due to a posterior noncystic mass, and the linear fluid signal tracked into the posterior epidural space at the L4–L5 level. A cleft in the ligamentum flavum was identified by probe at surgery, and this enabled the probe to be inserted into the epidural space without excising ligamentum flavum. Histological analysis showed that the fibrotic mass consisted of a collagen matrix that had a cystic component and exhibited a peripheral inflammatory reaction. This report shows that it is possible for an extended epidural cystic mass that occurs in Baastrup’s disease to change over time through peripheral inflammation into a cyst-containing fibrotic mass. PMID:20063020

  15. Neuropsychiatric Symptoms in Posterior Cortical Atrophy and Alzheimer Disease

    PubMed Central

    Crutch, Sebastian J.; Franco-Macías, Emilio; Gil-Néciga, Eulogio

    2016-01-01

    Background: Posterior cortical atrophy (PCA) is a rare neurodegenerative syndrome characterized by early progressive visual dysfunction in the context of relative preservation of memory and a pattern of atrophy mainly involving the posterior cortex. The aim of the present study is to characterize the neuropsychiatric profile of PCA. Methods: The Neuropsychiatric Inventory was used to assess 12 neuropsychiatric symptoms (NPS) in 28 patients with PCA and 34 patients with typical Alzheimer disease (AD) matched by age, disease duration, and illness severity. Results: The most commonly reported NPS in both groups were depression, anxiety, apathy, and irritability. However, aside from a trend toward lower rates of apathy in patients with PCA, there were no differences in the percentage of NPS presented in each group. All those patients presenting visual hallucinations in the PCA group also met diagnostic criteria for dementia with Lewy bodies (DLB). Auditory hallucinations were only present in patients meeting diagnosis criteria for DLB. Conclusion: Prevalence of the 12 NPS examined was similar between patients with PCA and AD. Hallucinations in PCA may be helpful in the differential diagnosis between PCA-AD and PCA-DLB. PMID:26404166

  16. The right posterior paravermis and the control of language interference

    PubMed Central

    Filippi, Roberto; Richardson, Fiona M.; Dick, Frederic; Leech, Robert; Green, David W.; Thomas, Michael S.C.; Price, Cathy J.

    2011-01-01

    Auditory and written language in humans' comprehension necessitates attention to the message of interest and suppression of interference from distracting sources. Investigating the brain areas associated with the control of interference is challenging because it is inevitable that activation of the brain regions that control interference co-occurs with activation related to interference per se. To isolate the mechanisms that control verbal interference, we used a combination of structural and functional imaging techniques in Italian and German participants who spoke English as a second language. First, we searched structural MRI images of Italian participants for brain regions where brain structure correlated with the ability to suppress interference from the unattended dominant language (Italian) while processing heard sentences in their weaker language (English). This revealed an area in the posterior paravermis of the right cerebellum where grey matter density was higher in individuals who were better at controlling verbal interference. Second, we found functional activation in the same region when our German participants made semantic decisions on written English words in the presence of interference from unrelated words in their dominant language (German). This combination of structural and functional imaging therefore highlights the contribution of the right posterior paravermis to the control of verbal interference. We suggest that the importance of this region for language processing has previously been missed because most fMRI studies limit the field of view to increase sensitivity; with the lower part of the cerebellum being the most likely region to be excluded. PMID:21775616

  17. Distinct Value Signals in Anterior and Posterior Ventromedial Prefrontal Cortex

    PubMed Central

    Smith, David V.; Hayden, Benjamin Y.; Truong, Trong-Kha; Song, Allen W.; Platt, Michael L.; Huettel, Scott A.

    2010-01-01

    The core feature of an economic exchange is a decision to trade one good for another, based on a comparison of relative value. Economists have long recognized, however, that the value an individual ascribes to a good during decision making (i.e., their relative willingness to trade for that good) does not always map onto the reward they actually experience. Here, we show that experienced value and decision value are represented in distinct regions of ventromedial prefrontal cortex (VMPFC) during the passive consumption of rewards. Participants viewed two categories of rewards – images of faces that varied in their attractiveness and monetary gains and losses – while being scanned using functional magnetic resonance imaging (fMRI). An independent market task, in which participants exchanged some of the money that they earned for brief views of attractive faces, determined the relative decision value associated with each category. We found that activation of anterior VMPFC increased with increasing experienced value, but not decision value, for both reward categories. In contrast, activation of posterior VMPFC predicted each individual's relative decision value for face and monetary stimuli. These results indicate not only that experienced value and decision value are represented in distinct regions of VMPFC, but also that decision value signals are evident even in the absence of an overt choice task. These results endorse the idea that decisions are made by comparing neural representations of the value of different goods encoded in posterior VMPFC in a common, relative currency. PMID:20164333

  18. Posterior Iris Fixated Intraocular Lens for Pediatric Traumatic Cataract

    PubMed Central

    Kavitha, V.; Balasubramanian, Preethi; Heralgi, Mallikarjun M.

    2016-01-01

    Purpose: To evaluate the postoperative visual outcomes and complications of posterior iris fixated intraocular lens (IFIOL) implantation for pediatric traumatic cataract. Methods: A retrospective clinical audit was performed of all the pediatric traumatic cataract patients who underwent lens removal and iris fixated lens implantation due to inadequate capsular support with or without corneal tear repair between January 2009 and December 2013. Data were collected and analyzed on the preoperative and postoperative visual outcomes and complications. Results: Twenty-five children (25 eyes; 21 males and 4 females) were enrolled with the mean age of 11 ± 4.0 years. There were 72% of eyes that underwent primary cataract removal with IFIOL implantation. Twenty-eight percent of eyes underwent corneal tear repair prior to intraocular lens (IOL) implantation. Preoperative best corrected visual acuity (BCVA) was hand motion in 32% eyes, counting fingers in 24%, and perception of light in 44%. Postoperative BCVA of 0-0.2 logarithm of minimum angle of resolution was reported in the 64% of eyes. One eye developed secondary glaucoma, one eye underwent re-enclavation, and none developed retinal complications. Conclusion: Posterior IFIOL implantation resulted in an improved visual outcome, low incidence of postoperative complications, and is a good alternative to other IOL, in the cases of pediatric traumatic cataract without adequate capsular support. PMID:27162456

  19. Patient risk factors' influence on survival of posterior composites.

    PubMed

    van de Sande, F H; Opdam, N J; Rodolpho, P A Da Rosa; Correa, M B; Demarco, F F; Cenci, M S

    2013-07-01

    This practice-based retrospective study evaluated the survival of resin composite restorations in posterior teeth, focusing on the influence of potential patient risk factors. In total, 306 posterior composite restorations placed in 44 adult patients were investigated after 10 to 18 yrs. The history of each restoration was extracted from the dental records, and a clinical evaluation was performed with those still in situ. The patient risk status was assessed for caries and "occlusal-stress" (bruxism-related). Statistical analysis was performed by the Kaplan-Meier method and Cox-regression multivariate analysis. In total, 30% of the restorations failed, of which 82% were found in patients with 1 or 2 risk factors. Secondary caries was the main reason of failure within caries-risk patients, whereas fracture was the main reason in "occlusal-stress-risk" patients. The patient variables gender and age did not significantly affect survival, but risk did (p < .001). Tooth type (p < .001), arch (p = .013), and pulpal vitality (p = .003) significantly affected restoration survival. Within the limits of this retrospective evaluation, the survival of restorations is affected by patient risk factors, which should be included in survival analyses of restorations. PMID:23690354

  20. Posterior Cricoarytenoid Muscle Dynamics in Canines and Humans

    PubMed Central

    Chhetri, Dinesh K.; Neubauer, Juergen; Sofer, Elazar

    2015-01-01

    Objective The posterior cricoarytenoid (PCA) muscle is the sole abductor of the glottis and serves important functions during respiration, phonation, cough, and sniff. The present study examines vocal fold abduction dynamics during PCA muscle activation. Study Design Basic science study using an in vivo canine model and human subjects. Methods In four canines and five healthy humans vocal fold abduction time was measured using high speed video recording. In the canines, PCA muscle activation was achieved using graded stimulation of the PCA nerve branch. The human subjects performed coughing and sniffing tasks. High speed video and audio signals were concurrently recorded. Results In the canines the vocal fold moved posteriorly, laterally, and superiorly during abduction. Average time to reach 10%, 50% and 90% abduction was 23, 50, and 100 ms with low stimulation, 24, 58, and 129 ms with medium stimulation, and 21, 49, and 117 ms with high level stimulation. In the humans, 100% abduction times for coughing and sniffing tasks were 79 and 193 ms, respectively. Conclusion The PCA abduction times in canines are within the range in humans. The results also further support the notion that PCA muscles are fully active during cough. Level of Evidence N/A (Animal studies and basic research) PMID:24781959

  1. Finite Element Modeling of the Posterior Eye in Microgravity

    NASA Technical Reports Server (NTRS)

    Feola, Andrew; Raykin, Julia; Mulugeta, Lealem; Gleason, Rudolph; Myers, Jerry G.; Nelson, Emily S.; Samuels, Brian; Ethier, C. Ross

    2015-01-01

    Microgravity experienced during spaceflight affects astronauts in various ways, including weakened muscles and loss of bone density. Recently, visual impairment and intracranial pressure (VIIP) syndrome has become a major concern for space missions lasting longer than 30 days. Astronauts suffering from VIIP syndrome have changes in ocular anatomical and visual impairment that persist after returning to earth. It is hypothesized that a cephalad fluid shift in microgravity may increase the intracranial pressure (ICP), which leads to an altered biomechanical environment of the posterior globe and optic nerve sheath (ONS).Currently, there is a lack of knowledge of how elevated ICP may lead to vision impairment and connective tissue changes in VIIP. Our goal was to develop a finite element model to simulate the acute effects of elevated ICP on the posterior eye and optic nerve sheath. We used a finite element (FE) analysis approach to understand the response of the lamina cribrosa and optic nerve to the elevations in ICP thought to occur in microgravity and to identify which tissue components have the greatest impact on strain experienced by optic nerve head tissues.

  2. REHABILITATION PROTOCOL AFTER ISOLATED POSTERIOR CRUCIATE LIGAMENT RECONSTRUCTION

    PubMed Central

    de Paula Leite Cury, Ricardo; Kiyomoto, Henry Dan; Rosal, Gustavo Fogolin; Bryk, Flávio Fernandes; de Oliveira, Victor Marques; de Camargo, Osmar Pedro Arbix

    2015-01-01

    To create a rehabilitation protocol following reconstruction of the posterior cruciate ligament (PCL), through a literature review. The literature review was conducted in the Medline and Embase databases, to search for data on biomechanical concepts and analyses relating to the posterior cruciate ligament of the knee. The search strategy was set up using the following rules: problem or injury in association with anatomical location terms; or surgical intervention procedure in association with rehabilitation terms. We began the process in this manner and subsequently introduced restrictions on certain terms to improve the search specificity. To design the protocol, a table was created for better data assessment, based on the time that elapsed between surgery and the start of physiotherapy. A rehabilitation protocol was created to improve weight-bearing control in the initial weeks after surgery, with the aid of a knee brace. Our aim was to achieve gains in total range of motion of the knee, which should be attained by the third month, thereby avoiding contractures resulting from the tissue healing process. Strengthening exercises and sensory-motor training were guided accordingly, thus avoiding overload on the graft and respecting the healing phases. The protocol proposed through this review was based on the current evidence relating to this subject. PMID:27047844

  3. Laparoscopic hiatal herniorrhaphy with posterior fundoplication for gastroesophageal reflux.

    PubMed

    Barr, L L

    1998-12-01

    Complications and side effects following laparoscopic antireflux procedures are common. This article describes an alternative laparoscopic technique to prevent gastroesophageal reflux. This method consists of posterior approximation of the diaphragmatic crura followed by a posterior fundoplication of approximately 270 degrees wrap. In avoiding the 360 degree wrap and obtaining length from the longitudinal axis of the stomach, it is not necessary to take down the gastrosplenic vessels. The principle of the procedure is to accentuate the cardioesophageal angle of His. No sutures are placed in the esophagus. While this article primarily concerns technique, it also constitutes a brief report on the first 50 patients who have been followed up for 1 year or more. All patients but one are free of reflux symptoms and have discontinued taking all medication. There has been no dysphagia to liquids, and solid food dysphagia has not lasted >1 month. Bloating from gas is minimal, as most patients are able to burp early in their recovery. An outcome paper describing preoperative and postoperative objective testing and evaluation is in process. PMID:9864104

  4. Neurobehavioral alterations in an adolescent following posterior fossa tumor resection.

    PubMed

    Baillieux, Hanne; De Smet, Hyo Jung; Lesage, Geoffrey; Paquier, Philippe; De Deyn, Peter P; Mariën, Peter

    2006-01-01

    The posterior fossa syndrome (PFS) consists of a variety of symptoms, including cerebellar mutism, behavioral disturbances and personality changes. We report longitudinal clinical, neuroradiological and neurobehavioral findings in a 19-year-old left-handed patient, diagnosed with attentional deficit hyperactivity disorder (ADHD) at the age of 12, who underwent posterior fossa tumor resection. Although the patient did not develop cerebellar mutism after surgery, marked apathy and emotional indifference, urinary retention, eye-lid apraxia and visual hallucinosis became apparent after a brief interval of normal functioning. Based on these findings it is argued that the PFS might be considered a semiological heterogeneous condition with variable clinical expressions. Long-term follow-up investigations revealed subtle, but significant cognitive and affective deficits, resembling the cerebellar cognitive affective syndrome in adults. As demonstrated by functional neuroimaging studies with SPECT, symptoms were associated with perfusional deficits in the anatomoclinically suspected supratentorial regions, reflecting the distant impact of the cerebellum on cognitive and affective functions. PMID:17134992

  5. Anterior and posterior MTL networks in aging and MCI.

    PubMed

    Das, Sandhitsu R; Pluta, John; Mancuso, Lauren; Kliot, Daria; Yushkevich, Paul A; Wolk, David A

    2015-01-01

    Two neuroanatomically dissociable, large-scale cortical memory networks, referred to as the anterior and posterior medial temporal lobe (MTL) networks have recently been described in young adults using resting-state blood oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI)-based functional connectivity (fc-BOLD). They have been hypothesized to subserve distinct mnemonic and non-memory cognitive functions and are thought to be associated with differential vulnerability in neurological disorders. In this article, we demonstrate the existence of these functional networks in an older adult population and in a cohort of patients diagnosed with amnestic mild cognitive impairment (aMCI). Anatomic subregions of interest in the MTL were defined using high-resolution T2-weighted MRI and used as seeds for defining the putative networks using fc-BOLD. Although the literature has suggested that the posterior MTL network is particularly vulnerable to early Alzheimer's disease, we show that both the networks are affected in MCI, to varying degrees, compared with the control group. Furthermore, cortical thickness in the brain regions defined by these networks was reduced in MCI. PMID:25444600

  6. Improvements in interpretation of posterior capsular opacification (PCO) images

    NASA Astrophysics Data System (ADS)

    Paplinski, Andrew P.; Boyce, James F.; Barman, Sarah A.

    2000-06-01

    We present further improvements to the methods of interpretation of the Posterior Capsular Opacification (PCO) images. These retro-illumination images of the back surface of the implanted lens are used to monitor the state of patient's vision after cataract operation. A common post-surgical complication is opacification of the posterior eye capsule caused by the growth of epithelial cells across the back surface of the capsule. Interpretation of the PCO images is based on their segmentation into transparent image areas and opaque areas, which are affected by the growth of epithelial cells and can be characterized by the increase in the image local variance. This assumption is valid in majority of cases. However, for different materials used for the implanted lenses it sometimes happens that the epithelial cells grow in a way characterized by low variance. In such a case segmentation gives a relatively big error. We describe an application of an anisotropic diffusion equation in a non-linear pre-processing of PCO images. The algorithm preserves the high-variance areas of PCO images and performs a low-pass filtering of small low- variance features. The algorithm maintains a mean value of the variance and guarantees existence of a stable solution and improves segmentation of the PCO images.

  7. Case report of a dilated odontome in the posterior mandible

    PubMed Central

    Almeida, Bruno; Silva, António; Pereira, Miguel; Silva, Mariana; Nunes, Stephanie

    2016-01-01

    Introduction Dens invaginatus (dens in dente) is a developmental malformation resulting from an invagination of enamel organ into the dental papilla, beginning at the crown and sometimes extending into the root before calcification occurs. Dilated odontome is the most extreme form of dens invaginatus and it is extremely rare in the posterior mandible. Presentation of case A 47 years old female patient with occasional episodes of diffuse pain and discomfort in the left posterior mandibular region. The extra-oral examination showed slight facial asymmetry. Panoramic and intra-oral X-rays show an intraosseous circular formation with radiopaque external limits and radiolucent interior. Discussion Computerized tomography scan reveals the bone integrity around the formation, as well as the independence of the neuro-vascular structures of the region. The most likely diagnostic option was dilated odontome. The enucleation procedure was carried out, and the fragments were sent to histopathological examination that revealed a diagnosis consistent with a dilated odontome. Conclusion In this case, the conservative surgical approach after planning was effective and predictable in the treatment of the pathology and patient symptoms without major complications. PMID:26780470

  8. Posterior foss avenous angiomas with drainage through the brain stem

    SciTech Connect

    Damiano, T.R.; Truwit, C.L. ); Dowd, C.F. ); Symonds, D.L. )

    1994-04-01

    To describe 11 cases of posterior fossa venous angiomas with drainage through the brain stem. Eleven cases of posterior fossa venous angioma with drainage through the brain stem were evaluated using MR. Correlation with known routes of venous drainage for the cerebellum and brain stem is made. Six of the 11 venous angiomas were found in the cerebellum, four in the brain stem; one involved both the cerebellum and brain stem. The cerebellar venous angiomas drained to subependymal veins about the fourth ventricle and dorsal pons. These then connected with an enlarged transmesencephalic or transpontine vein, to drain anteriorly to the anterior pontine veins. The brain stem angiomas had variable drainage depending on location. Evidence of hemorrhage was seen in five cases. Cerebellar and brain stem venous angiomas have several potential routes of drainage, including an enlarged vein traversing the pons, midbrain, or medulla. A knowledge of the normal venous anatomy of this region helps to understand the occurrence of these uncommon routes of venous drainage. 15 refs., 8 figs., 1 tab.

  9. Reverse Discrimination and Aggressive Behavior.

    ERIC Educational Resources Information Center

    Johnson, Stephen D.

    1980-01-01

    White subjects were aggressive toward Black opponents when contest results appeared to reflect elements of reverse discrimination; but they showed less aggressive behavior toward Black opponents when they thought their loss was due to their opponents' superior ability. (RL)

  10. The evolution of vasectomy reversal.

    PubMed

    Dickey, Ryan M; Pastuszak, Alexander W; Hakky, Tariq S; Chandrashekar, Aravind; Ramasamy, Ranjith; Lipshultz, Larry I

    2015-06-01

    In the USA, about 500,000 vasectomies are performed each year, with up to 6% of men requesting reversal. The technique of vasectomy reversal has evolved from macrosurgical to the implementation of both microscopic and robotic technologies. The very earliest attempts at vasectomy reversal, the vasoepididymostomy and vasovasostomy, have remained central in the treatment of male infertility and will continue to be so for years to come. As seen throughout its history, urological microsurgery has consistently implemented advanced techniques and state-of-the art technology in its craft, and its continued refinement will allow for even more favorable outcomes in the lives of patients seeking restoration of fertility following vasectomy. Here, we review the evolution of vasectomy reversal and its current techniques. PMID:25980804

  11. Deciphering records of geomagnetic reversals

    NASA Astrophysics Data System (ADS)

    Valet, Jean-Pierre; Fournier, Alexandre

    2016-06-01

    Polarity reversals of the geomagnetic field are a major feature of the Earth's dynamo. Questions remain regarding the dynamical processes that give rise to reversals and the properties of the geomagnetic field during a polarity transition. A large number of paleomagnetic reversal records have been acquired during the past 50 years in order to better constrain the structure and geometry of the transitional field. In addition, over the past two decades, numerical dynamo simulations have also provided insights into the reversal mechanism. Yet despite the large paleomagnetic database, controversial interpretations of records of the transitional field persist; they result from two characteristics inherent to all reversals, both of which are detrimental to an ambiguous analysis. On the one hand, the reversal process is rapid and requires adequate temporal resolution. On the other hand, weak field intensities during a reversal can affect the fidelity of magnetic recording in sedimentary records. This paper is aimed at reviewing critically the main reversal features derived from paleomagnetic records and at analyzing some of these features in light of numerical simulations. We discuss in detail the fidelity of the signal extracted from paleomagnetic records and pay special attention to their resolution with respect to the timing and mechanisms involved in the magnetization process. Records from marine sediments dominate the database. They give rise to transitional field models that often lead to overinterpret the data. Consequently, we attempt to separate robust results (and their subsequent interpretations) from those that do not stand on a strong observational footing. Finally, we discuss new avenues that should favor progress to better characterize and understand transitional field behavior.

  12. Reversible Shape Memory Optical Gratings

    NASA Astrophysics Data System (ADS)

    Li, Qiaoxi; Tippets, Cary; Fu, Yulan; Donev, Eugene; Turner, Sara; Ashby, Valerie; Lopez, Rene; Sheiko, Sergei

    2015-03-01

    Recent advancements in the understanding of the mechanisms that control shape memory in semi-crystalline polymers, has led to the development of protocols that allow for reversibility in complex shape transformations. The shifting between two programmable shapes is reversible without applying any external force. This is made possible by thermodynamically driven relaxation of extended polymer chains on heating is then inverted by kinetically preferred pathways of polymer crystallization on cooling. Reversible shapeshifting was applied to modulation of photonic gratings to create hands-free reversibly tunable optical elements. We have fabricated a sub-micron ratio optical square grating that presents reversible magnitude changes of its diffraction intensity (up to about 38% modulation) when subject to changes in temperature. This result is attributed to programmable changes in the grating height due to reversible shape memory and is repeatable over multiple cycles. Besides, roughness-induced variations in scattering signal observed upon heating-cooling cycles may offer another way to monitor kinetics of polymer melting and crystallization. Grants: NSF DMR-1407645,

  13. Topographically Organized Projection to Posterior Insular Cortex from the Posterior Portion of the Ventral Medial Nucleus (VMpo) in the Long-tailed Macaque Monkey

    PubMed Central

    Craig, A.D. (Bud)

    2014-01-01

    Prior anterograde tracing work identified somatotopically organized lamina I trigemino- and spino-thalamic terminations in a cytoarchitectonically distinct portion of posterolateral thalamus of the macaque monkey, named the posterior part of the ventral medial nucleus (VMpo; Craig, 2004b). Microelectrode recordings from clusters of selectively thermoreceptive or nociceptive neurons were used to guide precise micro-injections of various tracers in VMpo. A prior report (Craig and Zhang, 2006) described retrograde tracing results, which confirmed the selective lamina I input to VMpo and the antero-posterior (head to foot) topography. The present report describes the results of micro-injections of anterograde tracers placed at different levels in VMpo, based on the antero-posterior topographic organization of selectively nociceptive units and clusters over nearly the entire extent of VMpo. Each injection produced dense, patchy terminal labeling in a single coherent field within a distinct granular cortical area centered in the fundus of the superior limiting sulcus. The terminations were distributed with a consistent antero-posterior topography over the posterior half of the superior limiting sulcus. These observations demonstrate a specific VMpo projection area in dorsal posterior insular cortex that provides the basis for a somatotopic representation of selectively nociceptive lamina I spinothalamic activity. These results also identify the VMpo terminal area as the posterior half of interoceptive cortex; the anterior half receives input from the vagal-responsive and gustatory neurons in the basal part of the ventral medial nucleus (VMb). PMID:23853108

  14. Long-Term Outcome of Posterior Cervical Inclinatory Foraminotomy

    PubMed Central

    Heo, Juneyoung; Park, Hyung-Ki

    2016-01-01

    Objective A modified surgical technique of posterior cervical foramintomy called posterior cervical inclinatory foraminotomy (PCIF) was introduced in previous preliminary article. PCIF allows better preservation of facet joint and capsule than conventional techniques. The authors conducted a study to investigate long-term outcomes of PCIF. Methods We retrospectively reviewed demographic, radiologic, and clinical data from the patients who underwent PCIFs at our institution. Criteria included a minimum of 48 month follow-up and PCIFs for patients with radiculopathy from foraminal stenosis (C2–T1; single or multilevel) with persistent or recurrent root symptoms despite conservative treatment for more than 3 months. Patients who had undergone previous cervical operation were excluded. The visual analogue scale (VAS) score was used for clinical follow-up, and radiologic follow-up was performed to compare the changes of cervical sagittal alignment, focal angle and disc-space height of treated segment. Results The PCIFs were performed between April 2007 and March 2011 on 46 patients (32 males and 14 females) with a total of 73 levels affected. The average duration of follow-up was 74.4 months. Improvements in radiculopathic pain were seen in 39 patients (84.7%), and VAS score decreased from 6.82±1.9 to 2.19±1.9. Posterior neck pain also improved in 25 patients (71.4%) among 35 patients, and VAS score decreased from 4.97±2.0 to 2.71±1.9. The mean disc-space heights of treated segment were 5.41±1.03 mm preoperatively and decreased to 5.17±1.12 mm postoperatively. No statistically significant changes in cervical sagittal alignment, focal angle were seen during the follow-up period (Cox proportional hazards analysis and Student t-test, p>0.05). Conclusion The PCIF is highly effective in treating patients with cervical spondylotic radiculopathy, leading to long-lasting relief in pain. Long-term radiologic follow-up showed no significant spinal angular imbalance. PMID

  15. Multiple cytosolic calcium buffers in posterior pituitary nerve terminals.

    PubMed

    McMahon, Shane M; Chang, Che-Wei; Jackson, Meyer B

    2016-03-01

    Cytosolic Ca(2+) buffers bind to a large fraction of Ca(2+) as it enters a cell, shaping Ca(2+) signals both spatially and temporally. In this way, cytosolic Ca(2+) buffers regulate excitation-secretion coupling and short-term plasticity of release. The posterior pituitary is composed of peptidergic nerve terminals, which release oxytocin and vasopressin in response to Ca(2+) entry. Secretion of these hormones exhibits a complex dependence on the frequency and pattern of electrical activity, and the role of cytosolic Ca(2+) buffers in controlling pituitary Ca(2+) signaling is poorly understood. Here, cytosolic Ca(2+) buffers were studied with two-photon imaging in patch-clamped nerve terminals of the rat posterior pituitary. Fluorescence of the Ca(2+) indicator fluo-8 revealed stepwise increases in free Ca(2+) after a series of brief depolarizing pulses in rapid succession. These Ca(2+) increments grew larger as free Ca(2+) rose to saturate the cytosolic buffers and reduce the availability of Ca(2+) binding sites. These titration data revealed two endogenous buffers. All nerve terminals contained a buffer with a Kd of 1.5-4.7 µM, and approximately half contained an additional higher-affinity buffer with a Kd of 340 nM. Western blots identified calretinin and calbindin D28K in the posterior pituitary, and their in vitro binding properties correspond well with our fluorometric analysis. The high-affinity buffer washed out, but at a rate much slower than expected from diffusion; washout of the low-affinity buffer could not be detected. This work has revealed the functional impact of cytosolic Ca(2+) buffers in situ in nerve terminals at a new level of detail. The saturation of these cytosolic buffers will amplify Ca(2+) signals and may contribute to use-dependent facilitation of release. A difference in the buffer compositions of oxytocin and vasopressin nerve terminals could contribute to the differences in release plasticity of these two hormones. PMID:26880753

  16. Complete transthoracic resection of giant posterior mediastinal goiter: case report and review of surgical strategies

    PubMed Central

    Zhao, Honglin; Ren, Dian; Liu, Yi; Li, Xin; Wu, Yi; Chen, Gang; Chen, Jun

    2016-01-01

    Intrathoracic goiters generally occupy anterior mediastinum, rarely involving the posterior mediastinal space. Reported herein is a 54-year-old female with a giant posterior mediastinal mass that was successfully resected via right posterolateral thoracotomy. The final pathologic diagnosis was giant posterior mediastinal goiter. This patient has done well postoperatively, with no evidence of local recurrence at 12-month follow-up. Related surgical strategies in past publications are summarized. PMID:27217766

  17. Posterior Vertebral Column Resection for VATER/VACTERL Associated Spinal Deformity: A Case Report

    PubMed Central

    Cunningham, Matthew E.; Charles, Gina

    2006-01-01

    The VATER/VACTERL association is a syndrome notable for congenital vertebral malformations, anal atresia, cardiovascular anomalies, tracheoesophageal fistula, esophageal atresia, and renal or limb malformations. Vertebral malformations may include the entire spectrum of congenital spinal deformities, including kyphosis, as was seen in this case. A 14-year-old girl presented to our institution with severe rigid sagittal deformity in the thoracolumbar spine that had recurred following three prior spinal fusion surgeries: the first posterior only, the second anterior and posterior, and the third a posterior only proximal extension. These surgeries were performed to control progressive kyphosis from a complex failure of segmentation that resulted in a 66° kyphosis from T11 to L3 by the time she was 9 years old. Our evaluation revealed solid arthrodesis from the most recent procedures with resultant sagittal imbalance, and surgical options to restore balance included anterior and posterior revision spinal fusion with osteotomies, multiple posterior extension osteotomies with circumferential spine fusion, and posterior vertebral column resection with circumferential spine fusion. She was advised that multiple posterior extension osteotomies would likely be insufficient to restore sagittal balance in the setting of solid arthrodesis from anterior and posterior surgery, and that the posterior-only vertebral column resection would provide results equivalent to revision anterior and posterior surgery, without the morbidity of the anterior approach. She successfully underwent posterior vertebrectomy and circumferential spinal fusion with instrumentation and is doing well 2 years postoperatively. Severe rigid sagittal deformity can be effectively managed with a posterior-only surgical approach, vertebrectomy, and circumferential spinal fusion with instrumentation. PMID:18751773

  18. Transient contribution of left posterior parietal cortex to cognitive restructuring.

    PubMed

    Sutoh, Chihiro; Matsuzawa, Daisuke; Hirano, Yoshiyuki; Yamada, Makiko; Nagaoka, Sawako; Chakraborty, Sudesna; Ishii, Daisuke; Matsuda, Shingo; Tomizawa, Haruna; Ito, Hiroshi; Tsuji, Hiroshi; Obata, Takayuki; Shimizu, Eiji

    2015-01-01

    Cognitive restructuring is a fundamental method within cognitive behavioural therapy of changing dysfunctional beliefs into flexible beliefs and learning to react appropriately to the reality of an anxiety-causing situation. To clarify the neural mechanisms of cognitive restructuring, we designed a unique task that replicated psychotherapy during a brain scan. The brain activities of healthy male participants were analysed using functional magnetic resonance imaging. During the brain scan, participants underwent Socratic questioning aimed at cognitive restructuring regarding the necessity of handwashing after using the restroom. The behavioural result indicated that the Socratic questioning effectively decreased the participants' degree of belief (DOB) that they must wash their hands. Alterations in the DOB showed a positive correlation with activity in the left posterior parietal cortex (PPC) while the subject thought about and rated own belief. The involvement of the left PPC not only in planning and decision-making but also in conceptualization may play a pivotal role in cognitive restructuring. PMID:25775998

  19. Nonclosure of rectourethral fistula during posterior sagittal anorectoplasty: Our experience

    PubMed Central

    Jadhav, Sudhakar; Raut, Amit; Mandke, Jui; Patil, Santosh; Vora, Ravindra; Kittur, Dinesh

    2013-01-01

    Aim: To study the effect of nonclosure of rectourethral (RU) fistula and to do a comparative analysis of the complications with and without nonclosure of RU fistula during posterior sagittal anorectoplasty (PSARP) in anorectal malformation cases (ARM). Materials and Methods: A total of 68 cases of ARM were included in the study group, of which 34 cases were those in whom RU fistula was not closed (group A) during PSARP. Another 34 successive cases were included in study group B in whom the RU fistula was closed as is conventionally done by using interrupted sutures. Results: Comparatively, group A had none or minimum urological complications as compared to Group B. Conclusion: RU fistula closure is not mandatory during PSARP and nonclosure avoids urological complications. It especially avoids urethral complications, which are 100% preventable. PMID:23599574

  20. Asymptotic approximations to posterior distributions via conditional moment equations

    USGS Publications Warehouse

    Yee, J.L.; Johnson, W.O.; Samaniego, F.J.

    2002-01-01

    We consider asymptotic approximations to joint posterior distributions in situations where the full conditional distributions referred to in Gibbs sampling are asymptotically normal. Our development focuses on problems where data augmentation facilitates simpler calculations, but results hold more generally. Asymptotic mean vectors are obtained as simultaneous solutions to fixed point equations that arise naturally in the development. Asymptotic covariance matrices flow naturally from the work of Arnold & Press (1989) and involve the conditional asymptotic covariance matrices and first derivative matrices for conditional mean functions. When the fixed point equations admit an analytical solution, explicit formulae are subsequently obtained for the covariance structure of the joint limiting distribution, which may shed light on the use of the given statistical model. Two illustrations are given. ?? 2002 Biometrika Trust.

  1. Popliteal pseudoaneurysm after arthroscopic posterior cruciate ligament reconstruction.

    PubMed

    van Dorp, Karin B; Breugem, Stefan J M; Driessen, Marcel J M

    2014-09-01

    This report presents the case of a 30-year-old motocross (BMX) cyclist with a third-degree posterior cruciate ligament rupture. The technique used for reconstruction was the transtibial single-bundle autologous hamstring technique. Unfortunately, the procedure was complicated by a popliteal pseudoaneurysm, which was located in line with the tibial canal. The pseudoaneurysm was treated with an end-to-end anastomosis and the patient recovered without further complaints. In this case, the popliteal artery was damaged most probably by the edge of the reamer or the guide wire during removal. Vascular complications can be limb- and life-threatening. This case report aims to increase the awareness of this serious complication with a review of the literature. PMID:25229050

  2. Endovascular treatment of posterior condylar canal dural arteriovenous fistula.

    PubMed

    Maus, Volker; Söderman, Michael; Rodesch, Georges; Kabbasch, Christoph; Mpotsaris, Anastasios

    2016-01-01

    Posterior condylar canal dural arteriovenous fistulas (PCC DAVFs) are rare lesions that may present with pulse-synchronous bruit. In cases with venous reflux there is a risk of haemorrhage or even dementia. Diagnosis and endovascular treatment require a profound knowledge of the vascular anatomy of the craniocervical junction and comprehensive neurovascular imaging. We describe the clinical presentation, angiographic imaging and endovascular treatment of a PCC DAVF in a female patient with pulse-synchronous bruit as the presenting symptom. The fistula drained almost exclusively into the sigmoid sinus and internal jugular vein. There was no intracranial reflux. The PCC DAVF was treated with transvenous coil occlusion of the fistulous pouch in the condylar canal. Symptoms resolved immediately after intervention and the patient recovered quickly without any neurological deficits. MR angiography confirmed occlusion of the DAVF. The dural sinus was patent with normal blood flow. PMID:27247204

  3. Mapping genes with longitudinal phenotypes via Bayesian posterior probabilities.

    PubMed

    Musolf, Anthony; Nato, Alejandro Q; Londono, Douglas; Zhou, Lisheng; Matise, Tara C; Gordon, Derek

    2014-01-01

    Most association studies focus on disease risk, with less attention paid to disease progression or severity. These phenotypes require longitudinal data. This paper presents a new method for analyzing longitudinal data to map genes in both population-based and family-based studies. Using simulated systolic blood pressure measurements obtained from Genetic Analysis Workshop 18, we cluster the phenotype data into trajectory subgroups. We then use the Bayesian posterior probability of being in the high subgroup as a quantitative trait in an association analysis with genotype data. This method maintains high power (>80%) in locating genes known to affect the simulated phenotype for most specified significance levels (α). We believe that this method can be useful to aid in the discovery of genes that affect severity or progression of disease. PMID:25519410

  4. Posterior cerebral artery stroke presenting as alexia without agraphia.

    PubMed

    Sharma, Bhawna; Handa, Rahul; Prakash, Swayam; Nagpal, Kadam; Bhana, Indu; Gupta, Pankaj Kumar; Kumar, Sunil; Sisodiya, Mahendra Singh

    2014-12-01

    Alexia without agraphia (pure alexia) was the first of the disconnection syndromes to be described by Dejerine who reported a patient of alexia without agraphia secondary to an embolic occipital lobe infarct. We herein report a 55-year-old man who presented with alexia without agraphia with magnetic resonance imaging suggestive of left posterior cerebral artery infarct involving left occipital lobe and splenium of corpus callosum. Alexia without agraphia is a relatively uncommon clinical condition, which should always be thought in a patient presenting with difficulty in reading with normal visual acuity. Ophthalmologists should also be aware of this disconnection syndrome as many patients initially take their advice due to predominant visual complaints. Early diagnosis and treatment of this condition help in ensuring the patient and attendants about nonprogressive nature of the disease and may prevent further episodes of stroke. PMID:24935413

  5. Simple posterior frequency correction for vibrational spectra from molecular dynamics.

    PubMed

    Tikhonov, Denis S

    2016-05-01

    Vibrational spectra computed from molecular dynamics simulations with large integration time steps suffer from nonphysical frequency shifts of signals [M. Praprotnik and D. Janežič, J. Chem. Phys. 122, 174103 (2005)]. A simple posterior correction technique was developed for compensation of this behavior. It performs through replacement of abscissa in the calculated spectra using following formula: νcorrected=2⋅1-cos(2π⋅Δt⋅νinitial)2π⋅Δt, where ν are initial and corrected frequencies and Δt is the MD simulation time step. Applicability of this method was tested on gaseous infrared spectra of hydrogen fluoride and formic acid. PMID:27155626

  6. Transient contribution of left posterior parietal cortex to cognitive restructuring

    PubMed Central

    Sutoh, Chihiro; Matsuzawa, Daisuke; Hirano, Yoshiyuki; Yamada, Makiko; Nagaoka, Sawako; Chakraborty, Sudesna; Ishii, Daisuke; Matsuda, Shingo; Tomizawa, Haruna; Ito, Hiroshi; Tsuji, Hiroshi; Obata, Takayuki; Shimizu, Eiji

    2015-01-01

    Cognitive restructuring is a fundamental method within cognitive behavioural therapy of changing dysfunctional beliefs into flexible beliefs and learning to react appropriately to the reality of an anxiety-causing situation. To clarify the neural mechanisms of cognitive restructuring, we designed a unique task that replicated psychotherapy during a brain scan. The brain activities of healthy male participants were analysed using functional magnetic resonance imaging. During the brain scan, participants underwent Socratic questioning aimed at cognitive restructuring regarding the necessity of handwashing after using the restroom. The behavioural result indicated that the Socratic questioning effectively decreased the participants' degree of belief (DOB) that they must wash their hands. Alterations in the DOB showed a positive correlation with activity in the left posterior parietal cortex (PPC) while the subject thought about and rated own belief. The involvement of the left PPC not only in planning and decision-making but also in conceptualization may play a pivotal role in cognitive restructuring. PMID:25775998

  7. Resection of Posterior Mediastinal Tumors by Video Assisted Thoracic Surgery.

    PubMed

    Ali, Taimur Asif; Fatimi, Saulat Hasnain; Naeem, Syed Saad

    2015-07-01

    This case report illustrates successful Video Assisted Thoracic Surgery (VATS) performed on a 45-year-old woman and 52-year-old man presenting with a mass in left and right paravertebral space on the CT scan respectively. VATS has many benefits over traditional open operation (thoracotomy), resulting in less pain and shorten recovery time. However, VATS has higher equipment cost but when an experienced surgeon performs the surgery, better outcomes are achieved. VATS is not common in Pakistan's surgical setup as it is an expensive method of eradicating mediastinal pathologies and not every patient undergoes VATS. The primary objective of presenting these cases is to promote the use of VATS specifically for removal of posterior mediastinal tumors and improve the surgical outcomes. PMID:26208561

  8. A study of posterior column function in familial spastic paraplegia.

    PubMed Central

    Dimitrijevic, M R; Lenman, J A; Prevec, T; Wheatly, K

    1982-01-01

    A family is described in which affected members have clinical features consistent with the late onset form of Strümpell's Familial Spastic Paraplegia which is of dominant inheritance. Abnormalities in cortical somatosensory to peroneal nerve stimulation were found in all affected members of the family and in several who were clinically unaffected. In some cases responses were better defined at slow rates of stimulation. Peripheral nerve conduction velocity was normal. These changes are consistent with previous findings of degeneration in the posterior columns at necroscopy and with a dying back process in the first sensory neuron. Clinically unaffected members of the family with abnormalities in the somatosensory response may represent asymptomatic heterozygotes. PMID:7062069

  9. Applied sonoanatomy of the posterior triangle of the neck

    PubMed Central

    Ihnatsenka, Barys; Boezaart, André P

    2010-01-01

    The posterior triangle of the neck is an area of the body frequently visited by regional anesthesiologists, acute and chronic pain physicians, surgeons of all disciplines, and diagnosticians. It houses the entire brachial plexus from the roots to the divisions, the scalene muscles, the cervical sympathetic ganglions, the major blood vessels to and from the brain, the neuroforamina and various other structures of more or less importance to these physicians. Ultrasound (US) offers a handy visual tool for these structures to be viewed in real time and, therefore, its popularity and the need to understand it. We will discuss pertinent clinical anatomy of the neck and offer a basic visual explanation of the often-difficult two-dimensional (2-D) images seen with US. PMID:21472066

  10. Posterior encephalopathy subsequent to cyclosporin A presenting as irreversible abulia.

    PubMed

    Nishie, Makoto; Kurahashi, Kozo; Ogawa, Masaya; Yoshida, Yasuji; Midorikawa, Hiroshi

    2003-08-01

    A case of cyclosporin A (Cys A)-induced posterior encephalopathy developed into persistent abulia despite rapid and marked improvement of abnormal T2- and FLAIR MRI hyperintense regions. Diffusion-weighted MRI signal intensity was also high at the onset. This change is atypical in Cys A-induced encephalopathy and was thought to predict poor recovery from the encephalopathy. Persistent abulia was probably due to marked hypoperfusion in the whole cortex including bilateral frontal lobes and basal ganglia as detected by SPECT. Apart from the breakdown of the blood-brain barrier, direct toxicity of Cys A to the brain may play a role in the pathogenesis of chronic, irreversible encephalopathy. PMID:12924507

  11. Changes in artistic style after minor posterior stroke

    PubMed Central

    Annoni, J; Devuyst, G; Carota, A; Bruggimann, L; Bogousslavsky, J

    2005-01-01

    Background: Two professional painters experienced significant changes in their art as the main consequence of minor stroke located in the left occipital lobe or thalamus. Methods: The features of this artistic conversion were analysed on the basis of extensive neurological, neuropsychological, and psychiatric evaluations. Results: Both painters, initially unaware of the artistic changes, exhibited mild signs of executive dysfunction, but no general cognitive decline. The first painter, who showed mild visual-perceptive difficulties (dyschromatopsia and scotoma in his right upper visual field after left occipital stroke), together with increased anxiety and difficulty in emotional control, switched to a more stylised and symbolic art. The second painter, who also presented features of emotionalism related to his left latero-thalamic stroke, switched from an impressionist style to a more joyous and geometric, but more simplistic, abstract art. Conclusions: These findings show that mild cognitive and affective modifications due to focal posterior brain lesions can have significant repercussions on artistic expression. PMID:15897501

  12. Neglected Posterior Dislocation of Hip in Children - A Case Report

    PubMed Central

    Pal, Chandra Prakash; Kumar, Deepak; Sadana, Ashwani; Dinkar, Karuna Shankar

    2014-01-01

    Introduction: Traumatic dislocation of the hip in children is a rare injury. We report the outcome of 2 patients of neglected hip dislocation which were treated by open reduction and internal fixation by k-wires. Case Report: We treat 2 children both girls (one was of 4 years and other was 7 years of age). In both cases dislocation was unilateral and was not associated with any facture. Both cases were of posterior dislocation. in both cases open reduction and internal fixation was done by k wires. Hip spica was applied post operatively in both cases. The k wire was removed at 3 to 4 weeks. Patients were allowed to bear weight from gradual to full weight bearing after 6 weeks. Conclusion: We conclude that open reduction is a satisfactory treatment for neglected hip dislocation. It prevents not only deformity but also maintains limb length. PMID:27298953

  13. Spontaneous Posterior Uterine Rupture in Twin-Twin Transfusion Syndrome

    PubMed Central

    Smid, Marcela C.; Waltner-Toews, Rebecca; Goodnight, William

    2015-01-01

    Background The maternal and fetal risks of uterine distension in rapidly progressive twin-twin transfusion syndrome (TTTS) in the setting of prior uterine scar are poorly characterized. Case We present the case of a 42-year-old woman, G4P1201, at 21 weeks gestation with stage-1 TTTS who developed a spontaneous posterior uterine rupture necessitating emergent laparotomy and delivery of previable fetuses, possibly due to prior uterine scar from a displaced intrauterine device. Conclusion TTTS may be a risk factor for uterine rupture, including uterine rupture in atypical anatomic locations. Prior unrecognized uterine scars, including perforations, may magnify the risk for atypical uterine rupture in the setting of excessive uterine distension. PMID:26929874

  14. ECG artefacts mimicking atrial flutter in posterior fossa surgery.

    PubMed

    Rudigwa, Priya; Elakkumanan, Lenin Babu; Rajan, Sakthi P; Prakash, M V Satya

    2015-01-01

    ECG artefacts are defined as abnormalities in the monitored ECG, which result from measurement of cardiac potentials on the body surface and are not related to the electrical activity of the heart. In the operation theatre, the use of various types of electrical equipment may interfere with ECG interpretation. We describe our experience with artefacts resembling atrial fibrillation when a nerve integrity monitoring device was used on a patient undergoing posterior fossa surgery for epidermoid tumour. These artefacts resemble serious arrhythmias and may result in unwanted interventions. To enable better identification of such artefacts, a 12-lead ECG should be considered as it will display rhythm in all the leads; while artefacts will present in only a few leads, true arrhythmia will be present in all the 12 leads. Our case report aims to increase awareness regarding ECG artefacts and to explain how to distinguish them from actual arrhythmias. PMID:26021382

  15. Posterior spinal artery aneurysm rupture after ‘Ecstasy’ abuse

    PubMed Central

    Johnson, Jeremiah; Patel, Shnehal; Saraf-Lavi, Efrat; Aziz-Sultan, Mohammad Ali; Yavagal, Dileep R

    2014-01-01

    Posterior spinal artery (PSA) aneurysms are a rare cause of subarachnoid hemorrhage (SAH). The commonly abused street drug 3,4-methylenedioxymethamphetamine (MDMA) or ‘Ecstasy’ has been linked to both systemic and neurological complications. A teenager presented with neck stiffness, headaches and nausea after ingesting ‘Ecstasy’. A brain CT was negative for SAH but a CT angiogram suggested cerebral vasculitis. A lumbar puncture showed SAH but a cerebral angiogram was negative. After a spinal MR angiogram identified abnormalities on the dorsal surface of the cervical spinal cord, a spinal angiogram demonstrated a left PSA 2 mm fusiform aneurysm. The patient underwent surgery and the aneurysmal portion of the PSA was excised without postoperative neurological sequelae. ‘Ecstasy’ can lead to neurovascular inflammation, intracranial hemorrhage, SAH and potentially even de novo aneurysm formation and subsequent rupture. PSA aneurysms may be treated by endovascular proximal vessel occlusion or open surgical excision. PMID:24994748

  16. Population pharmacokinetic–pharmacodynamic analysis for sugammadex-mediated reversal of rocuronium-induced neuromuscular blockade

    PubMed Central

    Kleijn, Huub J; Zollinger, Daniel P; van den Heuvel, Michiel W; Kerbusch, Thomas

    2011-01-01

    AIMS An integrated population pharmacokinetic–pharmacodynamic model was developed with the following aims: to simultaneously describe pharmacokinetic behaviour of sugammadex and rocuronium; to establish the pharmacokinetic–pharmacodynamic model for rocuronium-induced neuromuscular blockade and reversal by sugammadex; to evaluate covariate effects; and to explore, by simulation, typical covariate effects on reversal time. METHODS Data (n = 446) from eight sugammadex clinical studies covering men, women, non-Asians, Asians, paediatrics, adults and the elderly, with various degrees of renal impairment, were used. Modelling and simulation techniques based on physiological principles were applied to capture rocuronium and sugammadex pharmacokinetics and pharmacodynamics and to identify and quantify covariate effects. RESULTS Sugammadex pharmacokinetics were affected by renal function, bodyweight and race, and rocuronium pharmacokinetics were affected by age, renal function and race. Sevoflurane potentiated rocuronium-induced neuromuscular blockade. Posterior predictive checks and bootstrapping illustrated the accuracy and robustness of the model. External validation showed concordance between observed and predicted reversal times, but interindividual variability in reversal time was pronounced. Simulated reversal times in typical adults were 0.8, 1.5 and 1.4 min upon reversal with sugammadex 16 mg kg−1 3 min after rocuronium, sugammadex 4 mg kg−1 during deep neuromuscular blockade and sugammadex 2 mg kg−1 during moderate blockade, respectively. Simulations indicated that reversal times were faster in paediatric patients and slightly slower in elderly patients compared with adults. Renal function did not affect reversal time. CONCLUSIONS Simulations of the therapeutic dosing regimens demonstrated limited impact of age, renal function and sevoflurane use, as predicted reversal time in typical subjects was always <2 min. PMID:21535448

  17. Complications of Posterior Vertebral Resection for Spinal Deformity

    PubMed Central

    Kim, Sung-Soo; Cho, Beom-Cheol; Kim, Jin-Hyok; Park, Ji-Yong; Lee, Beom-Jung; Suk, Se-Il

    2012-01-01

    Study Design Retrospective study. Purpose To evaluate the incidence and risk factors of complications following posterior vertebral resection (PVR) for spinal deformity. Methods A review of 233 patients treated with PVR at one institution over a nine-year period (1997 to 2005) was performed. The average age was 33.5 years. Complications were assessed in terms of surgical techniques (posterior vertebral column resection [PVCR] and decancellation osteotomy) and etiologies of deformity. Results Local kyphosis was corrected from 51.4° to 2.7°, thoracic scoliosis 63.9° to 24.5° (62.6% correction), and thoracolumbar or lumbar scoliosis 50.1° to 17.1° (67.6%). The overall incidence of complications was 40.3%. There was no significant difference between PVCR and decancellation osteotomy in the incidence of complications. There were more complications in the older patients (>35 years) than the younger (p < 0.05). Hig her than 3,000 ml of blood loss and 200 minutes of operation time increased the incidence of complications, with significant difference (p < 0.05). More than 5 levels of fusion significantly increased the total number of complications and postoperative neurologic deficit (p < 0.05). Most of the postoperative paraplegia cases had preoperative neurologic deficit. Preoperative kyphosis, especially in tuberculous sequela, had hig her incidences of complications and postoperative neurologic deficit (p < 0.05). More than 40° of kyphosis correction had the tendency to increase complications and postoperative neurologic deficit without statistical significance (p > 0.05). There was 1 mortality case by heart failure. Revision surgery was performed in 15 patients for metal failure or progressing curve. Conclusions The overall incidence of complications of PVR was 40.3%. Older age, abundant blood loss, preoperative kyphosis, and long fusion were risk factors for complications. PMID:23275809

  18. Viscoelastic properties of a spinal posterior dynamic stabilisation device.

    PubMed

    Lawless, Bernard M; Barnes, Spencer C; Espino, Daniel M; Shepherd, Duncan E T

    2016-06-01

    The purpose of this study was to quantify the frequency dependent viscoelastic properties of two types of spinal posterior dynamic stabilisation devices. In air at 37°C, the viscoelastic properties of six BDyn 1 level, six BDyn 2 level posterior dynamic stabilisation devices (S14 Implants, Pessac, France) and its elastomeric components (polycarbonate urethane and silicone) were measured using Dynamic Mechanical Analysis. The viscoelastic properties were measured over the frequency range 0.01-30Hz. The BDyn devices and its components were viscoelastic throughout the frequency range tested. The mean storage stiffness and mean loss stiffness of the BDyn 1 level device, BDyn 2 level device, silicone component and polycarbonate urethane component all presented a logarithmic relationship with respect to frequency. The storage stiffness of the BDyn 1 level device ranged from 95.56N/mm to 119.29N/mm, while the BDyn 2 level storage stiffness ranged from 39.41N/mm to 42.82N/mm. BDyn 1 level device and BDyn 2 level device loss stiffness ranged from 10.72N/mm to 23.42N/mm and 4.26N/mm to 9.57N/mm, respectively. No resonant frequencies were recorded for the devices or its components. The elastic property of BDyn 1 level device is influenced by the PCU and silicone components, in the physiological frequency range. The viscoelastic properties calculated in this study may be compared to spinal devices and spinal structures. PMID:27018832

  19. A Novel Rodent Model of Posterior Ischemic Optic Neuropathy

    PubMed Central

    Wang, Yan; Brown, Dale P.; Duan, Yuanli; Kong, Wei; Watson, Brant D.; Goldberg, Jeffrey L.

    2014-01-01

    Objectives To develop a reliable, reproducible rat model of posterior ischemic optic neuropathy (PION) and study the cellular responses in the optic nerve and retina. Methods Posterior ischemic optic neuropathy was induced in adult rats by photochemically induced ischemia. Retinal and optic nerve vasculature was examined by fluorescein isothiocyanate–dextran extravasation. Tissue sectioning and immunohistochemistry were used to investigate the pathologic changes. Retinal ganglion cell survival at different times after PION induction, with or without neurotrophic application, was quantified by fluorogold retrograde labeling. Results Optic nerve injury was confirmed after PION induction, including local vascular leakage, optic nerve edema, and cavernous degeneration. Immunostaining data revealed microglial activation and focal loss of astrocytes, with adjacent astrocytic hypertrophy. Up to 23%, 50%, and 70% retinal ganglion cell loss was observed at 1 week, 2 weeks, and 3 weeks, respectively, after injury compared with a sham control group. Experimental treatment by brain-derived neurotrophic factor and ciliary neurotrophic factor remarkably prevented retinal ganglion cell loss in PION rats. At 3 weeks after injury, more than 40% of retinal ganglion cells were saved by the application of neurotrophic factors. Conclusions Rat PION created by photochemically induced ischemia is a reproducible and reliable animal model for mimicking the key features of human PION. Clinical Relevance The correspondence between the features of this rat PION model to those of human PION makes it an ideal model to study the pathophysiologic course of the disease, most of which remains to be elucidated. Furthermore, it provides an optimal model for testing therapeutic approaches for optic neuropathies. PMID:23544206

  20. Cytology and Functionally Correlated Circuits of Human Posterior Cingulate Areas

    PubMed Central

    Vogt, Brent A.; Vogt, Leslie; Laureys, Steven

    2008-01-01

    Human posterior cingulate cortex (PCC) and retrosplenial cortex (RSC) form the posterior cingulate gyrus, however, monkey connection and human imaging studies suggest that PCC area 23 is not uniform and atlases mislocate RSC. We histologically assessed these regions in 6 postmortem cases, plotted a flat map, and characterized differences in dorsal (d) and ventral (v) area 23. Subsequently, functional connectivity of histologically guided regions of interest (ROI) were assessed in 163 [18F]fluorodeoxyglucose human cases with PET. Compared to area d23, area v23 had a higher density and larger pyramids in layers II, IIIc, and Vb and more intermediate neurofilament-expressing neurons in layer Va. Coregisrtration of each case to standard coordinates showed that the ventral branch of the splenial sulci coincided with the border between d/v PCC at −5.4±0.17 cm from the vertical plane and +1.97±0.08 cm from the bi-commissural line. Correlation analysis of glucose metabolism using histologically guided ROIs suggested important circuit differences including dorsal and ventral visual stream inputs, interactions between the vPCC and subgenual cingulate cortex, and preferential relations between dPCC and the cingulate motor region. The RSC, in contrast, had restricted correlated activity with pericallosal cortex and thalamus. Visual information may be processed with an orbitofrontal link for synthesis of signals to drive premotor activity through dPCC. Review of the literature in terms of a PCC duality suggests that interactions of dPCC, including area 23d, orients the body in space via the cingulate motor areas, while vPCC interacts with subgenual cortex to process self-relevant emotional and non-emotional information and objects and self reflection. PMID:16140550