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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 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

  7. 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

  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 (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

  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 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

  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. 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

  4. 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

  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 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

  9. 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

  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. 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

  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. 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

  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. 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

  18. 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

  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. 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

  3. 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

  4. 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

  5. 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

  6. 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

  7. 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

  8. [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

  9. 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

  10. 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.

  11. 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

  12. 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

  13. 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

  14. 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

  15. 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

  16. 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

  17. 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

  18. 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

  19. 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

  20. 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.

  1. 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

  2. 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

  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: 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

  5. 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

  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. [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

  11. 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

  12. 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

  13. 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

  14. 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

  15. 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

  16. 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

  17. 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

  18. 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

  19. 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

  20. 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

  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 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

  5. 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

  6. 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

  7. 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

  8. 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

  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. 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

  11. 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

  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 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

  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

    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

  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 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

  9. 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

  10. 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

  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. 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

  18. 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

  19. 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

  20. 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. ...

  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. 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

  7. 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

  8. 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

  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. 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

  12. 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

  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. 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

  17. 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

  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 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

  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 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. ...

  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. 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

  15. 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

  16. 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

  17. 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

  18. [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

  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 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

  1. 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

  2. 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

  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. 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

  12. 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

  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. 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

  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. 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

  8. 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

  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. 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

  18. [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

  19. 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

  20. 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

  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. 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

  3. 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.

  4. 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

  5. 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

  6. 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.

  7. 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

  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. 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.

  16. 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…

  17. 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.

  18. 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…

  19. 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.…

  20. 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

  1. 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

  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. 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.

  6. 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

  7. 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

  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