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  1. [Posterior reversible encephalopathy syndrome].

    PubMed

    Petrović, Branko; Kostić, Vladimir; Sternić, Nadezda; Kolar, Jovo; Tasić, Nebojsa

    2003-01-01

    Reversible Posterior Leukoencephalopathy Syndrome was introduced into clinical practice in 1996 in order to describe unique syndrome, clinically expressed during hypertensive and uremic encephalopathy, eclampsia and during immunosuppressive therapy [1]. First clinical investigations showed that leucoencephalopathy is major characteristic of the syndrome, but further investigations showed no significant destruction in white cerebral tissue [2, 3, 4]. In majority of cases changes are localise in posterior irrigation area of the brain and in the most severe cases anterior region is also involved. Taking into consideration all above mentioned facts, the suggested term was Posterior Reversible Encephalopathy Syndrome (PRES) for the syndrome clinically expressed by neurological manifestations derived from cortical and subcortical changes localised in posterior regions of cerebral hemispheres, cerebral trunk and cerebellum [5]. Patient, aged 53 years, was re-hospitalized in Cardiovascular Institute "Dediwe" two months after successful aorto-coronary bypass performed in June 2001 due to the chest bone infection. During the treatment of the infection (according to the antibiogram) in September 2001, patient in evening hours developed headache and blurred vision. The recorded blood pressure was 210/120 mmHg so antihypertensive treatment was applied (Nifedipin and Furosemid). After this therapy there was no improvement and intensive headache with fatigue and loss of vision developed. Neurological examination revealed cortical blindness and left hemiparesis. Manitol (20%, 60 ccm every 3 hours) and i.v. Nytroglicerin (high blood pressure). Brain CT revealed oedema of parieto-occipital regions of both hemispheres, more emphasized on the right. (Figure 1a, b, c). There was no sign of focal ischemia even in deeper sections (Figure 1d, e, f). Following three days enormous high blood pressure values were registered. On the fourth day the significant clinical improvement occurred

  2. The posterior reversible encephalopathy syndrome.

    PubMed

    Sanjay, K Mandal; Partha, P Chakraborty

    2008-09-01

    The posterior/potentially reversible encephalopathy syndrome is a unique syndrome encountered commonly in hypertensive encephalopathy. A 13-year-old boy presented with of intermittent high grade fever, throbbing headache and non-projective vomiting for 5 days. The patient had a blood pressure of 120/80 mmHg but fundoscopy documented grade 3 hypertensive retinopathy. The patient improved symptomatically following conservative management. However, on the 5(th) post-admission day headache reappeared, and blood pressure measured at that time was 240/120 mmHg. Neuroimaging suggested white matter abnormalities. Search for the etiology of secondary hypertension led to the diagnosis of pheochromocytoma. Repeated MRI after successful surgical excision of the tumor patient showed reversal of white matter abnormalities. Reversible leucoencephalopathy due to pheochromocytoma have not been documented in literature previously.

  3. Duloxetine-related posterior reversible encephalopathy syndrome

    PubMed Central

    Zappella, Nathalie; Perier, François; Pico, Fernando; Palette, Catherine; Muret, Alexandre; Merceron, Sybille; Girbovan, Andrei; Marquion, Fabien; Legriel, Stephane

    2016-01-01

    Abstract Background: Posterior reversible encephalopathy syndrome (PRES) has well-established links with several drugs. Whether a link also exists with serotonin–norepinephrine reuptake inhibitor such as duloxetine is unclear. Methods: We report on a patient who developed PRES with a coma and myoclonus related to hypertensive encephalopathy a few days after starting duloxetine treatment. Magnetic resonance imaging was performed and catecholamine metabolites assayed. Results: The patient achieved a full recovery after aggressive antihypertensive therapy and intravenous anticonvulsant therapy. Conclusions: The clinical history, blood and urinary catecholamine and serotonin levels, and response to treatment strongly suggest that PRES was induced by duloxetine. Duloxetine should be added to the list of causes of PRES. PMID:27537580

  4. Cyclophosphamide-induced reversible posterior leukoencephalopathy syndrome.

    PubMed

    Abenza-Abildua, Maria Jose; Fuentes, Blanca; Diaz, Domingo; Royo, Aranzazu; Olea, Teresa; Aguilar-Amat, Maria Jose; Diez-Tejedor, Exuperio

    2009-01-01

    Reversible posterior leukoencephalopathy syndrome (RPLS) is a clinical radiological syndrome, characterised by acute headache, altered consciousness, seizures and hypertension. The most frequent causes are hypertensive encephalopathy, eclampsia and some immunosuppressive therapies. The pathogenesis remains unclear, but it appears to be related to altered cerebral circulation, producing oedema that can be seen on MRI, and it resolves in 2 or 3 weeks. In the present report, a possible first reported case of cyclophosphamide-induced RPLS in a 27-year-old man with high blood pressure (HBP) and glomerulonephritis caused by Goodpasture syndrome, treated with cyclophosphamide during the last month and prednisone for glomerulonephritis resulting from Goodpasture syndrome without other immunosuppressive drugs, is described.Symptoms appeared during a hypertensive crisis, but when cyclophosphamide was replaced by rituximab and hypertension was controlled, the patient did not have neurological symptoms. Almost all reported cases induced by immunosuppressive therapy or other causes were associated with hypertension as well.

  5. Cyclophosphamide-induced reversible posterior leukoencephalopathy syndrome

    PubMed Central

    Abenza-Abildua, Maria Jose; Fuentes, Blanca; Diaz, Domingo; Royo, Aranzazu; Olea, Teresa; Aguilar-Amat, Maria Jose; Diez-Tejedor, Exuperio

    2009-01-01

    Reversible posterior leukoencephalopathy syndrome (RPLS) is a clinical radiological syndrome, characterised by acute headache, altered consciousness, seizures and hypertension. The most frequent causes are hypertensive encephalopathy, eclampsia and some immunosuppressive therapies. The pathogenesis remains unclear, but it appears to be related to altered cerebral circulation, producing oedema that can be seen on MRI, and it resolves in 2 or 3 weeks. In the present report, a possible first reported case of cyclophosphamide-induced RPLS in a 27-year-old man with high blood pressure (HBP) and glomerulonephritis caused by Goodpasture syndrome, treated with cyclophosphamide during the last month and prednisone for glomerulonephritis resulting from Goodpasture syndrome without other immunosuppressive drugs, is described. Symptoms appeared during a hypertensive crisis, but when cyclophosphamide was replaced by rituximab and hypertension was controlled, the patient did not have neurological symptoms. Almost all reported cases induced by immunosuppressive therapy or other causes were associated with hypertension as well. PMID:21686794

  6. Posterior reversible encephalopathy syndrome(PRES).

    PubMed

    Sudulagunta, Sreenivasa Rao; Sodalagunta, Mahesh Babu; Kumbhat, Monica; Settikere Nataraju, Aravinda

    2017-04-01

    Posterior reversible encephalopathy syndrome (PRES) is a clinico-radiological syndrome characterized by a headache, seizures, altered mental status and visual loss and characterized by white matter vasogenic edema affecting the posterior occipital and parietal lobes of the brain predominantly. This clinical syndrome is increasingly recognized due to improvement and availability of brain imaging specifically magnetic resonance imaging (MRI). A 35-year-old female with the history of unsafe abortion and massive blood transfusion 10 days ago was brought to the emergency room with three episodes of generalized tonic-clonic seizures, urinary incontinence and altered sensorium since 3 hours. MRI brain showed bilateral occipital, parietal, frontal cortex and subcortical white matter T2/Fluid-attenuated inversion recovery hyperintensities, suggestive of PRES. The patient improved after management with intravenous fluids, antibiotics, antiepileptics and monitoring of blood pressure. If recognized and treated early, the clinical syndrome commonly resolves within a week. PRES can be a major problem in rapid and massive blood transfusion. A high index of suspicion and prompt treatment can reduce morbidity, mortality and pave the path for early recovery.

  7. [Posterior reversible encephalopathy: beyond the original description].

    PubMed

    Avecillas-Chasín, Josué M; Matías-Guiu, Jordi A; Bautista-Balbás, Luis

    2015-07-16

    Introduccion. La encefalopatia posterior reversible (EPR) es una entidad clinicorradiologica caracterizada tipicamente por cuadros de cefalea, alteraciones visuales y crisis epilepticas, asociada a edema vasogeno corticosubcortical reversible en la neuroimagen. Objetivo. Presentar una revision de los aspectos fisiopatologicos de esta entidad y tambien de las asociaciones de la EPR descritas en la bibliografia. Desarrollo. Existe una serie de factores desencadenantes bien conocidos, como las crisis hipertensivas, la eclampsia o ciertos medicamentos. La descripcion de cada vez mas casos atipicos desde un punto de vista clinico y radiologico, asi como de posibles nuevos factores desencadenantes, obliga a una redefinicion de la entidad. Conclusiones. La EPR es un conjunto de manifestaciones clinicas y radiologicas que no se pueden enmarcar dentro la palabra 'sindrome'. Aunque la EPR se ha comunicado como irreversible en ciertos casos, el concepto de reversibilidad debe mantenerse en la definicion de esta entidad, ya que, en la mayor parte de los casos, el rapido control de la condicion desencadenante de la EPR permite la reversibilidad de las lesiones.

  8. Posterior reversible encephalopathy syndrome: a variant of hypertensive encephalopathy.

    PubMed

    Mirza, Ayoub

    2006-06-01

    Posterior reversible encephalopathy syndrome (PRES) is a recently described variant of hypertensive encephalopathy characterized by headache, visual disturbances and altered mental function. Its causes are diverse and in contrast to hypertensive encephalopathy, it can develop without significant elevation of blood pressure. This syndrome is mostly reversible when correctly managed; however, failure to recognize it can lead to cerebral infarction and death.

  9. Brainstem variant of posterior reversible encephalopathy syndrome: A case report

    PubMed Central

    Caranci, Ferdinando; Belfiore, Maria Paola; Manzi, Francesca; Pagliano, Pasquale; Cirillo, Sossio

    2015-01-01

    Posterior reversible encephalopathy syndrome (PRES) is a clinico-radiological condition, generally observed in conjunction with severe and acute hypertension, that involves mainly the posterior head areas (occipital and temporal lobes) and anterior “watershed” areas. In this syndrome it is rare to observe a predominant involvement of the brainstem. We describe the clinical and radiological findings in a patient with brainstem involvement, discussing its pathophysiological features and possible differential diagnosis. PMID:26515750

  10. Brainstem variant of posterior reversible encephalopathy syndrome: A case report.

    PubMed

    Tortora, Fabio; Caranci, Ferdinando; Belfiore, Maria Paola; Manzi, Francesca; Pagliano, Pasquale; Cirillo, Sossio

    2015-12-01

    Posterior reversible encephalopathy syndrome (PRES) is a clinico-radiological condition, generally observed in conjunction with severe and acute hypertension, that involves mainly the posterior head areas (occipital and temporal lobes) and anterior "watershed" areas. In this syndrome it is rare to observe a predominant involvement of the brainstem. We describe the clinical and radiological findings in a patient with brainstem involvement, discussing its pathophysiological features and possible differential diagnosis.

  11. Posterior reversible encephalopathy syndrome in acute intermittent porphyria.

    PubMed

    Zhao, Bi; Wei, QianQian; Wang, YunHan; Chen, YongPing; Shang, HuiFang

    2014-09-01

    Acute intermittent porphyria is an inherited disease that is rarely diagnosed in prepubertal children. It can affect the autonomic, peripheral, and central nervous system. Posterior reversible encephalopathy syndrome is a clinicoradiological entity characterized by headache, seizures, altered consciousness, and visual disorder associated with potentially reversible neuroradiological abnormalities predominantly in the parieto-occipital lobes. We report a child with acute intermittent porphyria who presented with radiological manifestations suggestive of posterior reversible encephalopathy syndrome. A 9-year-old girl underwent an appendectomy after developing abdominal pain. She subsequently developed bilateral visual disturbance, confusion, seizures, hypertension, tachycardia, nausea, vomiting, constipation, dark tea-colored urine, and recurrent abdominal pain. Initial brain magnetic resonance imaging revealed hyperintense gyriform lesions on T2-weighted images and hypointense to isointense lesions on T1-weighted images in both parieto-occipital lobes with mild enhancement. The diagnosis of acute intermittent porphyria was confirmed by increased urinary excretion of porphyrin precursors. Her clinical signs gradually improved after intravenous high-dose glucose treatment and symptomatic therapies. A repeat magnetic resonance imaging confirmed complete resolution of the parieto-occipital lesions, suggesting with posterior reversible encephalopathy syndrome. The association of abdominal pain, mental status changes, and autonomic dysfunction should arouse the suspicion of acute intermittent porphyria. Acute intermittent porphyria can be associated with posterior reversible encephalopathy syndrome. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Reversible posterior leucoencephalopathy syndrome associated with bone marrow transplantation.

    PubMed

    Teive, H A; Brandi, I V; Camargo, C H; Bittencourt, M A; Bonfim, C M; Friedrich, M L; de Medeiros, C R; Werneck, L C; Pasquini, R

    2001-09-01

    Reversible posterior leucoencephalopathy syndrome (RPLS) has previously been described in patients who have renal insufficiency, eclampsia, hypertensive encephalopathy and patients receiving immunosuppressive therapy. The mechanism by which immunosuppressive agents can cause this syndrome is not clear, but it is probably related with cytotoxic effects of these agents on the vascular endothelium. We report eight patients who received cyclosporine A (CSA) after allogeneic bone marrow transplantation or as treatment for severe aplastic anemia (SSA) who developed posterior leucoencephalopathy. The most common signs and symptoms were seizures and headache. Neurological dysfunction occurred preceded by or concomitant with high blood pressure and some degree of acute renal failure in six patients. Computerized tomography studies showed low-density white matter lesions involving the posterior areas of cerebral hemispheres. Symptoms and neuroimaging abnormalities were reversible and improvement occurred in all patients when given lower doses of CSA or when the drug was withdrawn. RPLS may be considered an expression of CSA neurotoxicity.

  13. Posterior interosseous reverse forearm flap: experience with 80 consecutive cases.

    PubMed

    Angrigiani, C; Grilli, D; Dominikow, D; Zancolli, E A

    1993-08-01

    The results of an anatomic investigation performed in 40 fresh cadaver specimens and 80 consecutive clinical cases of the posterior interosseous reverse forearm flap are reported. It was observed that there is a choke anastomosis between the recurrent dorsal branch of the anterior interosseous artery and the posterior interosseous artery at the level of the middle third of the posterior forearm. Ink injections through a catheter placed in the distal part of the anterior interosseous artery stained the distal and middle thirds of the posterior forearm, but the proximal third remained unstained; this secondary territory cannot be captured through the choke anastomosis between the anterior interosseous artery and the posterior interosseous artery. Intravital fluorescein injection into the distal arterior interosseous artery revealed (under ultraviolet light) that the distal third of the posterior forearm is irrigated by direct flow through the recurrent branch of the arterior interosseous artery (the traditionally called distal anastomosis of the interosseous arteries). Therefore, we can assume that the blood flow is not reversed when the so-called posterior interosseous reverse forearm flap is raised. From this point of view, this flap could be renamed as the recurrent dorsal anterior interosseous direct flap; however, the classical name is maintained for practical purposes. From the venous standpoint, the cutaneous area included in this flap belongs to an oscillating type of venous territory and is connected to the deep system through an interconnecting venous perforator that accompanies a medial cutaneous arterial branch located at 1 to 2 cm distal to the middle point of the forearm.(ABSTRACT TRUNCATED AT 250 WORDS)

  14. Hypertensive posterior reversible encephalopathy syndrome causing posterior fossa edema and hydrocephalus.

    PubMed

    Grossbach, Andrew J; Abel, Taylor J; Hodis, Brendan; Wassef, Shafik N; Greenlee, Jeremy D W

    2014-02-01

    Posterior reversible encephalopathy syndrome (PRES) is a well characterized entity resulting from the inability of cerebral autoregulation to adequately protect the brain from uncontrolled hypertension. It primarily affects the occipital lobes, but can also involve the structures in the posterior fossa including the brainstem and cerebellum. Treatment usually consists of strict blood pressure control, but more aggressive management may be indicated with acutely worsening neurological status. We present a patient with hypertensive encephalopathy that resulted in hydrocephalus and brainstem compression necessitating surgical decompression requiring ventriculostomy and suboccipital craniectomy. In rare cases, PRES can present with severe brainstem compression requiring emergent posterior fossa decompression. When brainstem signs are present on exam, emergent posterior fossa decompression may be safer than ventriculostomy alone. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Management of Posterior Reversible Syndrome in Preeclamptic Women

    PubMed Central

    Poma, S.; Delmonte, M. P.; Gigliuto, C.; Imberti, R.; Delmonte, M.; Arossa, A.; Iotti, G. A.

    2014-01-01

    Posterior reversible encephalopathy syndrome (PRES) is a neurological syndrome associated with a number of conditions including preeclampsia. It is characterized by seizures, alteration of consciousness, visual disturbances, and symmetric white matter abnormalities, typically in the posterior parietooccipital regions of the cerebral hemispheres, at computed tomography (CT) and magnetic resonance (MRI). We report three new cases of PRES in preeclamptic patients and describe the management of these patients. We present a brief review of other cases in the literature, with particular attention to the anesthetic management. PMID:25506009

  16. Posterior reversible encephalopathy syndrome associated with left horizontal gaze palsy

    PubMed Central

    Studyvin, Sarah; Al-Halawani, Moh’d; Amireh, Sawsan; Thawabi, Mohammad

    2017-01-01

    Posterior reversible encephalopathy syndrome (PRES) is characterized by rapid onset of symptoms including headache, seizures, altered consciousness, and visual disturbance, as well as radiologic findings of focal reversible vasogenic edema. Multiple visual disturbances have been described in PRES, such as hemianopia, visual neglect, auras, visual hallucinations, and cortical blindness. However, horizontal gaze palsy has not been previously reported. We report a 72-year-old female who presented with blurred vision, severe headache, lethargy, and later developed seizures. She was found to have left horizontal gaze palsy with intact vestibulo-ocular reflex. Brain magnetic resonance imaging (MRI) showed severe edema throughout the subcortical white matter, and signal in the posterior parietal and occipital lobes. She was diagnosed with PRES associated with supranuclear gaze palsy. PMID:28361069

  17. Epinephrine-induced posterior reversible encephalopathy syndrome: a case report.

    PubMed

    Gharabawy, Ramez; Pothula, Vijayasimha R; Rubinshteyn, Vladimir; Silverberg, Michael; Gave, Asaf A

    2011-09-01

    Posterior reversible encephalopathy syndrome (PRES) is a rare disorder that is usually associated with hypertensive crises. It is often missed but may be diagnosed by head computed tomographic (CT) scan or magnetic resonance imaging. An adolescent man presented for elective right shoulder arthroscopic bankart repair. Arthroscopy was performed using a solution of normal saline with 3.3 mg/L of epinephrine for irrigation. Postoperatively, the patient presented with hypertension and epileptiform activity. A CT scan of the head showed PRES.

  18. Posterior reversible encephalopathy syndrome in children: a case series

    PubMed Central

    Emeksiz, Serhat; Kutlu, Nurettin Onur; Çaksen, Hüseyin; Alkan, Gülsüm; Yıkmaz, Hülya Şeker; Tokgöz, Hüseyin

    2016-01-01

    Posterior reversible encephalopathy syndrome is characterized by hypertension, seizure, headache, clouding of consciousness, and visual disturbance, and is diagnosed in the presence of typical lesions on magnetic resonance imaging. We retrospectively evaluated five patients who were diagnosed as having posterior reversible encephalopathy syndrome and followed up in Meram Medical Faculty, Pediatric Intensive Care and Hematology wards, between January 2010 and January 2014. We reviewed the demographic and clinical data, and neuroimaging findings. The primary diseases of the subjects included acute lymphocytic leukemia (n=2), Henoch-Schönlein purpura (n=1), systemic lupus erythematous (n=1), and acute poststreptococcal glomerulonephritis (n=1). The mean age was 10±4.58 years (range, 5–14 years). Acute elevation of blood pressure was found in all patients (n=5). Initial neurologic manifestations included seizure, clouding of consciousness, headache, and visual disturbance. After the diagnosis was made through clinical evaluations and magnetic resonance imaging, complete clinical recovery was obtained in all patients with the appropriate therapeutic approach. In conclusion, posterior reversible encephalopathy syndrome should be considered in the differential diagnosis of patients who present with encephalopathy and underlying diseases such as nephritis, vasculitis, malignancy accompanied by hypertension, and a history of use of medication. PMID:28123335

  19. Reversible Hypertensive Myelopathy-The Spinal Cord Variant of Posterior Reversible Encephalopathy Syndrome.

    PubMed

    Gocmen, Rahsan; Ardicli, Didem; Erarslan, Yasin; Duzova, Ali; Anlar, Banu

    2017-04-01

    The posterior reversible encephalopathy syndrome (PRES) is a well-known clinical and radiologic entity mainly affecting the territory of the posterior cerebral circulation. Spinal cord involvement is extremely rare, and as of yet, only a few cases have been reported in the literature. The present case describes a reversible, longitudinal spinal cord lesion in a patient with high blood pressure. We discuss the differential diagnosis of longitudinal myelopathy and focus on the clinical presentation, diagnosis, and management of the "spinal cord variant of PRES." Georg Thieme Verlag KG Stuttgart · New York.

  20. Hippocampal sclerosis and chronic epilepsy following posterior reversible encephalopathy syndrome.

    PubMed

    Kapina, Viktoria; Vargas, Maria-Isabel; Wohlrab, Gabriele; Vulliemoz, Serge; Fluss, Joel; Seeck, Margitta

    2013-12-01

    Chronic epilepsy has rarely been reported after posterior reversible encephalopathy syndrome (PRES) and the association with hippocampal sclerosis has been suggested only once before. We report the case of a girl admitted at the age of 8 years with idiopathic nephrotic syndrome. On the second day of admission, she presented with focal complex seizures and cerebral MRI showed posterior encephalopathy and no hippocampal sclerosis. MRI after one month confirmed the diagnosis of PRES. The seizures recurred and the girl developed pharmacoresistant epilepsy and was admitted to our hospital for further investigation. Cerebral MRI three years after the diagnosis of PRES showed hippocampal sclerosis which was not present on the initial MRI. We conclude that there is a triggering role of PRES in the development of hippocampal sclerosis. Hippocampal sclerosis may have resulted from seizure-associated damage, alternatively, hypertensive encephalopathy may have led to hippocampal damage via a vascular mechanism.

  1. Posterior reversible encephalopathy syndrome following a scorpion sting.

    PubMed

    Porcello Marrone, Luiz Carlos; Marrone, Bianca Fontana; Neto, Felipe Kalil; Costa, Francisco Cosme; Thomé, Gustavo Gomes; Aramburu, Martin Brandolt; Schilling, Lucas Porcello; Pascoal, Tharick Ali; Gadonski, Giovani; Huf Marrone, Antônio Carlos; da Costa, Jaderson Costa

    2013-10-01

    Posterior reversible encephalopathy syndrome (PRES) is a clinicoradiologic entity not yet understood, that is present with transient neurologic symptoms and particular radiological findings. The most common imaging pattern in PRES is the presence of edema in the white matter of the posterior portions of both cerebral hemispheres. The cause of PRES is unclear. We report a case of 13-year-old male who was stung by a scorpion and developed a severe headache, visual disturbance, and seizures and had the diagnosis of PRES with a good outcome. Numerous factors can trigger this syndrome, most commonly: acute elevation of blood pressure, abnormal renal function, and immunosuppressive therapy. There are many cases described showing the relationship between PRES and eclampsia, transplantation, neoplasia and chemotherapy treatment, systemic infections, renal disease acute, or chronic. However, this is the first case of PRES following a scorpion sting.

  2. Posterior reversible encephalopathy syndrome and association with systemic lupus erythematosus.

    PubMed

    Ferreira, T S; Reis, F; Appenzeller, S

    2016-10-01

    Posterior reversible encephalopathy syndrome (PRES) is a neurological complex disorder with many clinical associations and causative factors. It is important to recognize this condition because early diagnosis and treatment usually result in its complete resolution, radiological imaging becoming the key for the correct diagnosis. We retrospectively reviewed charts and magnetic resonance imaging findings in the University of Campinas from January 2005 to July 2015, selecting three cases of patients with systemic lupus erythematosus syndrome who developed PRES, for whom risk factors, characteristics, magnetic resonance imaging findings and neurological resolution were analyzed. We also conducted a review of the English-language literature. The three cases had neurological symptoms like acute onset of headache, altered mental status, cortical blindness and seizures. Brain magnetic resonance imaging demonstrated posterior cortical and white matter alterations involving posterior brain territories, which were more conspicuous on T2-weighted and fluid-attenuated inversion recovery. Spectroscopy, diffusion-weighted imaging and susceptibility-weighted imaging were also important for neuroradiological evaluation. Immunosuppressive drugs were taken in all cases. Partial clinical and radiological recovery was observed in two cases, and complete resolution was observed in the third patient. We found 52 cases of PRES in systemic lupus erythematosus patients. Almost all patients were women 94%, ranging from 8 to 62 years old. Posterior brain territory involvements were found in 98% of patients. Hemorrhagic complications involved 26% of patients, becoming a risk factor for clinical sequels. The total percentage of patients with no complete resolution of radiological findings on follow-up images was 27.5%. In patients with autoimmune disorders, endothelial dysfunction may occur secondary to autoimmunity and the use of cytotoxic drugs, supposedly facilitating the occurrence of more

  3. Posterior reversible encephalopathy syndrome in Guillain-Barré syndrome.

    PubMed

    Chen, Adam; Kim, Jennifer; Henderson, Galen; Berkowitz, Aaron

    2015-05-01

    Autonomic dysfunction is a well-known complication of Guillain-Barré syndrome (GBS) and may manifest as hemodynamic fluctuations. Posterior reversible encephalopathy syndrome (PRES) is commonly associated with acute hypertension, but is rarely reported to occur in association with GBS. We describe a patient with GBS who developed PRES in the setting of autonomic dysfunction and review the clinical features of all 12 previously reported patients with co-occurrence of GBS and PRES. Almost all cases have occurred in women over the age of 55, raising the possibility of increased sensitivity to dysautonomia in this patient group. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. A reversible posterior leucoencephalopathy syndrome including blindness caused by preeclampsia

    PubMed Central

    Vandenbossche, G; Maquet, J; Vroonen, P; Lambert, G; Nisolle, M; Kridelka, F; Emonts, E

    2016-01-01

    Complications of (pre)eclampsia may involve multiple systems and organs. Neurological symptoms may occur. Visual symptoms concern up to 25% the of patients with severe preeclampsia and 50% of the patients with eclampsia. An uncommon effect of severe preeclampsia is sudden blindness. Blindness may be part of a clinical and radiological presentation named Posterior Reversible Encephalopathy Syndrome (PRES). PRES may lead to permanent neurological deficit, recurrences or death. We report the case of a 24-year-old Caucasian patient, gravida 5 para 2 who developed preeclampsia and PRES complicated with blindness at 32 weeks of gestation. Optimal care allowed visual symptoms to resolve within 24 hours and a favourable maternal outcome and no long- term sequelae. We describe different causes and manifestations of PRES and highlight the need for immediate care in order to optimize the chance of symptoms reversibility. PMID:28003872

  5. Isolated cerebellar involvement in posterior reversible encephalopathy syndrome.

    PubMed

    Li, Dujuan; Lian, Lifei; Zhu, Suiqiang

    2015-10-15

    Posterior reversible encephalopathy syndrome (PRES) is a serious and increasingly recognized disorder in humans. However, isolated cerebellar involvement in PRES is extremely uncommon. In this study, we sought to investigate its clinical and radiological features by describing a cohort of cases with PRES and isolated cerebellar involvement. We report 2 patients with PRES with only cerebellar involvement and identified additional 9 cases using the PubMed database with the MeSH terms "posterior reversible encephalopathy syndrome", "hypertensive encephalopathy", "hypertension", "cerebellum", "encephalopathy", and "magnetic resonance imaging". We then collectively analyzed the clinical and imaging characteristics of these 11 cases. The average age was 28years, with 8 male and 3 female patients. All cases had severe acute hypertension and T2 hyperintensity on MRI exclusively centered within the cerebellum. Of 11 patients, 7 had hypertensive retinopathy, a favorable clinical course with only antihypertensive treatment, and resolution of the cerebellar lesions on follow-up imaging. A total of 5 of the 11 patients received external ventricular drainage due to obstructive hydrocephalus and only 2 of the 11 had a seizure. Isolated cerebellar involvement in PRES may be a unique variant that affects younger, male cases with severe acute hypertension and hypertensive retinopathy, but not necessarily seizure. Most patients have full recovery after fast control of blood pressure. Awareness of atypical neuroimaging features in PRES is critical for appropriate treatment. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Reversible cerebral vasoconstriction syndrome presenting as subarachnoid hemorrhage, reversible posterior leukoencephalopathy, and cerebral infarction.

    PubMed

    Noda, Kazuyuki; Fukae, Jiro; Fujishima, Kenji; Mori, Kentaro; Urabe, Takao; Hattori, Nobutaka; Okuma, Yasuyuki

    2011-01-01

    Reversible cerebral vasoconstriction syndrome (RCVS) is characterized by acute severe headache with or without additional neurological symptoms and reversible cerebral vasoconstriction. Unruptured aneurysm has been reported in some cases with RCVS. We report a severe case of a 53-year-old woman with RCVS having an unruptured cerebral aneurysm and presenting as cortical subarachnoid hemorrhage, reversible posterior leukoencephalopathy syndrome, and cerebral infarction. She was successfully treated with corticosteroids and a calcium channel blocker and the aneurysm was clipped. Her various complications are due to the responsible vasoconstriction that started distally and progressed towards proximal arteries. This case demonstrates the spectrum of presentations of RCVS, a clinically complicated condition.

  7. Acute Pancreatitis and Posterior Reversible Encephalopathy Syndrome: A Case Report.

    PubMed

    Magno Pereira, Vítor; Marote Correia, Luís; Rodrigues, Tiago; Serrão Faria, Gorete

    2016-09-01

    The posterior reversible encephalopathy syndrome is a neurological syndrome characterized by headache, confusion, visual disturbances and seizures associated with identifiable areas of cerebral edema on imaging studies. The authors report the case of a man, 33 years-old, leukodermic with a history of chronic alcohol and tobacco consumption, who is admitted to the emergency department for epigastric pain radiating to the back and vomiting with about six hours of evolution and an intense holocranial headache for two hours. His physical examination was remarkable for a blood pressure of 190/100 mmHg and tenderness in epigastrium. His analytical results revealed emphasis on amylase 193 U/L and lipase 934 U/L. During the observation in the emergency department,he presented a generalized tonic-clonic seizure. Abdominal ultrasonography was performed and suggestive of pancreatitis withoutgallstones signals. Head computed tomography showed subarachnoid haemorrhage and a small right frontal cortical haemorrhage. The brain magnetic resonance imaging done one week after admission showed areas of a bilateral and symmetrical T2 / FLAIR hyperintensities in the subcortical white matter of the parietal and superior frontal regions, suggesting a diagnosis of posterior reversible encephalopathy syndrome. Abdominal computed tomography (10 days after admission) demonstrated a thickened pancreas in connection with inflammation and two small hypodense foci in the anterior part of the pancreas body, translating small foci of necrosis. The investigation of a thrombophilic defect revealed a heterozygous G20210A prothrombin gene mutation. The patient was discharged without neurological sequelae and asymptomatic. The follow-up brain magnetic resonance imaging confirmed the reversal of the lesions, confirming the diagnosis.

  8. Reversible hypertensive encephalomyelopathy - the spinal variant of the posterior reversible encephalopathy syndrome.

    PubMed

    Wu, Teddy Y; Wei, Diana Y; Jordan, Anthony; Kenedi, Chris; Smith, Andrew D; Kilfoyle, Dean H

    2015-05-01

    Posterior reversible encephalopathy syndrome (PRES) is characterised clinically by encephalopathy, headache, visual disturbance and/or focal neurological symptoms. Bilateral cerebral oedema on T2 MRI sequences within the posterior cerebral white matter is the radiological hallmark, although involvement of the frontal lobe, basal ganglia and brainstem can occur. PRES with spinal cord involvement has been rarely reported and is under-recognised due to lack of myelopathic features in nearly half of the reported cases. We report a patient with PRES with spinal cord involvement and review the literature.

  9. Posterior reversible encephalopathy syndrome in children with kidney disease.

    PubMed

    Gera, D N; Patil, S B; Iyer, A; Kute, V B; Gandhi, S; Kumar, D; Trivedi, H L

    2014-01-01

    Posterior reversible encephalopathy syndrome (PRES) is a clinic-radiographic entity of heterogeneous etiologies that are grouped together because of similar findings on neuro-imaging and associated symptom complex of headache, vision loss, altered mentation, and seizures. Although usually considered benign and reversible, characteristics of this syndrome in pediatric patients remain obscure. This case series included 11 patients (8 males, 3 females, age 3-15 years) of PRES during September 2010 to February 2012 out of a total 660 renal pediatric patients (1.66%). We studied their clinical profile, contributory factors, and outcome. Presenting symptoms were headache in 73%, dimness of vision or cortical blindness in 36%, seizures in 91%, and altered mentation in 55%. The associated renal diseases were acute renal failure (55%), chronic renal failure (9%), and 36% had normal renal function. The contributory factors were uncontrolled hypertension (100%), severe hypoproteinemia (9%), persistent hypocalcemia (9%), hemolytic uremic syndrome (36%), cyclosporine toxicity (9%), lupus nephritis (9%), high hematocrit (9%), and pulse methylprednisolone (9%). Brain imaging showed involvement of occipito-parietal area (100%) and other brain areas (63%). All but one patient of hemolytic uremic syndrome had complete clinical neurological recovery in a week, and all had normal neurological imaging after 4-5 weeks. PRES is an underdiagnosed entity in pediatric renal disease patients. Associated hypertension, renal disease, and immunosuppressive treatment are important triggers. Early diagnosis and treatment of comorbid conditions is of prime importance for early reversal of syndrome.

  10. Posterior reversible encephalopathy syndrome in children with kidney disease

    PubMed Central

    Gera, D. N.; Patil, S. B.; Iyer, A.; Kute, V. B.; Gandhi, S.; Kumar, D.; Trivedi, H. L.

    2014-01-01

    Posterior reversible encephalopathy syndrome (PRES) is a clinic-radiographic entity of heterogeneous etiologies that are grouped together because of similar findings on neuro-imaging and associated symptom complex of headache, vision loss, altered mentation, and seizures. Although usually considered benign and reversible, characteristics of this syndrome in pediatric patients remain obscure. This case series included 11 patients (8 males, 3 females, age 3-15 years) of PRES during September 2010 to February 2012 out of a total 660 renal pediatric patients (1.66%). We studied their clinical profile, contributory factors, and outcome. Presenting symptoms were headache in 73%, dimness of vision or cortical blindness in 36%, seizures in 91%, and altered mentation in 55%. The associated renal diseases were acute renal failure (55%), chronic renal failure (9%), and 36% had normal renal function. The contributory factors were uncontrolled hypertension (100%), severe hypoproteinemia (9%), persistent hypocalcemia (9%), hemolytic uremic syndrome (36%), cyclosporine toxicity (9%), lupus nephritis (9%), high hematocrit (9%), and pulse methylprednisolone (9%). Brain imaging showed involvement of occipito-parietal area (100%) and other brain areas (63%). All but one patient of hemolytic uremic syndrome had complete clinical neurological recovery in a week, and all had normal neurological imaging after 4-5 weeks. PRES is an underdiagnosed entity in pediatric renal disease patients. Associated hypertension, renal disease, and immunosuppressive treatment are important triggers. Early diagnosis and treatment of comorbid conditions is of prime importance for early reversal of syndrome. PMID:24574628

  11. Posterior reversible encephalopathy syndrome caused by presumed Takayasu arteritis

    PubMed Central

    Lee, Ki Wuk; Lee, Sang Taek

    2016-01-01

    Takayasu arteritis (TA) is a chronic inflammatory disease of unknown etiology that affects mainly the aorta, main aortic branches, and pulmonary arteries. Diverse neurological manifestations of TA have rarely been reported in children. Posterior reversible encephalopathy syndrome (PRES) is a neuroradiological condition that presents with headache, seizure, visual disturbances, and characteristic lesions on imaging. Inflammatory condition and severe hypertension in TA can cause PRES. We report of a 5-year-old girl with presumed TA who presented with PRES and chronic total occlusion in the renal artery. The findings on magnetic resonance imaging suggested PRES. Left nephrectomy was performed for total occlusion of the left renal artery, and the confirmatory diagnosis of TA was based on the pathologic findings of the renal artery. PMID:28018468

  12. Neuropathology of a fatal case of posterior reversible encephalopathy syndrome.

    PubMed

    Kheir, John N; Lawlor, Michael W; Ahn, Edward S; Lehmann, Leslie; Riviello, James J; Silvera, V Michelle; McManus, Michael; Folkerth, Rebecca D

    2010-01-01

    The pathology of posterior reversible encephalopathy syndrome (PRES) is undefined, since it is rarely fatal and is biopsied in only exceptional circumstances. We describe rapidly progressive PRES following stem cell transplant for acute lymphoblastic leukemia. After development of altered mental status, this 8-year-old girl had T2 prolongation of the white matter in a posterior-dominant distribution, eventually developing cerebellar edema, hemorrhage, hydrocephalus, and herniation. Despite surgical and medical management, she died 36 hours later. At autopsy, the occipital and cerebellar white matter and focal occipital cortical gray matter showed a spectrum of microvascular changes, including dilated perivascular spaces containing proteinaceous exudates and macrophages, as well as fibrinoid necrosis and acute hemorrhage, in a distribution corresponding to the neuroimaging abnormalities and reminiscent of those seen in patients with acute hypertensive encephalopathy. Of note, similar microvascular changes were not seen in the kidney or other systemic sites. Thus, the findings indicate a brain-specific microvascular compromise as the substrate of PRES, at least in the rare instance of cases progressing to fatal outcome.

  13. Study of Posterior Reversible Encephalopathy Syndrome in Children With Acute Lymphoblastic Leukemia After Induction Chemotherapy.

    PubMed

    Tang, Ji-Hong; Tian, Jian-Mei; Sheng, Mao; Hu, Shao-Yan; Li, Yan; Zhang, Li-Ya; Gu, Qing; Wang, Qi

    2016-03-01

    Increasing occurrence of posterior reversible encephalopathy syndrome has been reported in children with acute lymphoblastic leukemia. However, the etiology of posterior reversible encephalopathy syndrome is not clear. To study the possible pathogenetic mechanisms and treatment of this complication, we reported 11 cases of pediatric acute lymphoblastic leukemia who developed posterior reversible encephalopathy syndrome after induction chemotherapy. After appropriate treatment, the clinical symptoms of posterior reversible encephalopathy syndrome in most cases disappeared even though induction chemotherapy continued. During the 1-year follow-up, no recurrence of posterior reversible encephalopathy syndrome was observed. Although the clinical and imaging features of posterior reversible encephalopathy syndrome may be diverse, posterior reversible encephalopathy syndrome should be recognized as a possible important complication of acute lymphoblastic leukemia when neurologic symptoms appear. In line with previous reports, our study also indicated that posterior reversible encephalopathy syndrome was reversible when diagnosed and treated at an early stage. Thus, the occurrence of posterior reversible encephalopathy syndrome should be considered and investigated to optimize the early induction scheme of acute lymphoblastic leukemia treatment.

  14. Reversible cerebral vasoconstriction syndrome combined with posterior reversible encephalopathy syndrome after heart transplantation.

    PubMed

    Ban, Seung Pil; Hwang, Gyojun; Kim, Chang Hyeun; Kwon, O-Ki

    2017-08-01

    Reversible cerebral vasoconstriction syndrome (RCVS) combined with posterior reversible encephalopathy syndrome (PRES) is a rare complication in patients treated with immunosuppressants. A 52-year-old male patient presented with seizures after heart transplantation. The patient was suspected of having PRES on brain images. Despite the strict blood pressure control, the patient presented with altered mentality and the brain images showed a newly developed large acute infarction. Digital subtraction angiography (DSA) revealed the classic "sausage on a string" appearance of the cerebral arteries - potential feature of RCVS. To our knowledge, this is the first case report to describe RCVS combined with PRES after heart transplantation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Reversible posterior leukoencephalopathy in the course of Goodpasture syndrome.

    PubMed

    Ozkok, Abdullah; Elcioglu, Omer Celal; Bakan, Ali; Atilgan, Kadir Gokhan; Alisir, Sabahat; Odabas, Ali Riza

    2012-01-01

    Reversible posterior leukoencephalopathy syndrome (RPLS) is characterized by headache, altered consciousness, seizures, and cortical blindness. The most frequent etiological factors are hypertension, kidney diseases, and immunosuppressive drugs such as steroids and cyclophosphamide. Herein we present a case of a 22-year-old female patient presented with alveolar hemorrhage and acute renal failure necessitating hemodialysis. In renal biopsy, necrotizing crescentic glomerulonephritis and immunofluorescence pattern compatible with Goodpasture syndrome were found. Anti-glomerular basement membrane antibody result was positive. At follow-up, respiratory failure ensued, steroid pulse treatment was started, and she was transferred to intensive care unit (ICU). In the ICU, she had visual disturbances and blindness together with seizures. Cranial magnetic resonance imaging (MRI) revealed irregular T2- and fluid-attenuated inversion recovery (FLAIR)-weighted lesions in bilateral occipital lobes. On clinical and radiological grounds, RPLS was diagnosed. With the supportive and anti-hypertensive treatment, RPLS was resolved without a sequela. Subsequent cranial MRI was totally normal. In the literature, RPLS associated with Goodpasture syndrome was reported only once. Hypertension and methylprednisolone might be the responsible etiologies in this case.

  16. [Reversible posterior leukoencephalopathy syndrome associated with carbamazepine-induced hypertension].

    PubMed

    Furuta, Natsumi; Fujita, Yukio; Sekine, Akiko; Ikeda, Masaki; Okamoto, Koichi

    2009-04-01

    A 21-year-old man developed idiopathic trigeminal neuralgia, and was admitted to our hospital. Although neuralgia was promptly resolved after oral carbamazepine (CBZ) administration, he developed arterial hypertension (from 110/60 mmHg to 170/126 mmHg) followed by consciousness disturbance several days after the initiation of carbamazepine. MRI T2-weighted, FLAIR and ADC images demonstrated transient hyperintense lesions of the bilateral fronto-parieto-occipital subcortical white matter. These lesions showed isointensity on diffusion-weighted images. Since these alterations suggested the presence of vasogenic edema induced by hypertension, we diagnosed him as having reversible posterior leukoencephalopathy syndrome (RPLS) induced by hypertension. Persistent hypertension despite the administration of various anti-hypertension drugs finally improved after oral CBZ therapy was discontinued. Therefore, we considered that hypertension was induced by oral CBZ therapy. This is a rare case in which high blood pressure was caused by CBZ. There is no previous report of RPLS induced by CBZ administration. Further investigation to determine whether CBZ is capable of causing arterial hypertension is warranted.

  17. Posterior reversible encephalopathy syndrome in a patient with lupus nephritis.

    PubMed

    Kadikoy, Huseyin; Haque, Waqar; Hoang, Vu; Maliakkal, Joseph; Nisbet, John; Abdellatif, Abdul

    2012-05-01

    Posterior reversible encephalopathy syndrome (PRES) is characterized by acute onset of headache, nausea, focal neurological deficits or seizures along with radiological findings of white matter defects in the parietal and occipital lobes. Causes of PRES include uremia, hypertensive encephalopathy, eclampsia and immunosuppressive medications. Usually, the treatment of choice involves correcting the underlying abnormality. We describe an unusual case of recurrent PRES caused by uremia during a lupus flare in a patient with biopsy-proven Class IV Lupus Nephritis (LN) with vasculitis. PRES in systemic lupus erythematosis (SLE) is a rare clinical phenomenon and, when reported, it is associated with hypertensive encephalopathy. Our patient did not have hypertensive crisis, but had uremic encephalopathy. The patient's PRES-related symptoms resolved after initiation of hemodialysis. The temporal correlation of the correction of the uremia and the resolution of the symptoms of PRES show the etiology to be uremic encephalopathy, making this the first reported case of uremia-induced PRES in Class IV LN with vasculitis.

  18. 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.

  19. Determinants of Recovery from Severe Posterior Reversible Encephalopathy Syndrome

    PubMed Central

    Legriel, Stephane; Schraub, Olivier; Azoulay, Elie; Hantson, Philippe; Magalhaes, Eric; Coquet, Isaline; Bretonniere, Cedric; Gilhodes, Olivier; Anguel, Nadia; Megarbane, Bruno; Benayoun, Laurent; Schnell, David; Plantefeve, Gaetan; Charpentier, Julien; Argaud, Laurent; Mourvillier, Bruno; Galbois, Arnaud; Chalumeau-Lemoine, Ludivine; Rivoal, Michel; Durand, François; Geffroy, Arnaud; Simon, Marc; Stoclin, Annabelle; Pallot, Jean-Louis; Arbelot, Charlotte; Nyunga, Martine; Lesieur, Olivier; Troché, Gilles; Bruneel, Fabrice; Cordoliani, Yves-Sébastien; Bedos, Jean-Pierre; Pico, Fernando

    2012-01-01

    Objective Few outcome data are available about posterior reversible encephalopathy syndrome (PRES). We studied 90-day functional outcomes and their determinants in patients with severe PRES. Design 70 patients with severe PRES admitted to 24 ICUs in 2001–2010 were included in a retrospective cohort study. The main outcome measure was a Glasgow Outcome Scale (GOS) of 5 (good recovery) on day 90. Main Results Consciousness impairment was the most common clinical sign, occurring in 66 (94%) patients. Clinical seizures occurred in 57 (81%) patients. Median mean arterial pressure was 122 (105–143) mmHg on scene. Cerebral imaging abnormalities were bilateral (93%) and predominated in the parietal (93%) and occipital (86%) white matter. Median number of brain areas involved was 4 (3–5). Imaging abnormalities resolved in 43 (88%) patients. Ischaemic and/or haemorrhagic complications occurred in 7 (14%) patients. The most common causes were drug toxicity (44%) and hypertensive encephalopathy (41%). On day 90, 11 (16%) patients had died, 26 (37%) had marked functional impairments (GOS, 2 to 4), and 33 (56%) had a good recovery (GOS, 5). Factors independently associated with GOS<5 were highest glycaemia on day 1 (OR, 1.22; 95%CI, 1.02–1.45, p = 0.03) and time to causative-factor control (OR, 3.3; 95%CI, 1.04–10.46, p = 0.04), whereas GOS = 5 was associated with toxaemia of pregnancy (preeclampsia/eclampsia) (OR, 0.06; 95%CI, 0.01–0.38, p = 0.003). Conclusions By day 90 after admission for severe PRES, 44% of survivors had severe functional impairments. Highest glycaemia on day 1 and time to causative-factor control were strong early predictors of outcomes, suggesting areas for improvement. PMID:23024751

  20. Development of epilepsy after posterior reversible encephalopathy syndrome.

    PubMed

    Heo, Kyoung; Cho, Kyoo Ho; Lee, Moon Kyu; Chung, Su Jin; Cho, Yang-Je; Lee, Byung In

    2016-01-01

    This study was intended to describe the risk of epilepsy subsequent to posterior reversible encephalopathy syndrome (PRES) and the clinical features of post-PRES epilepsy. We retrospectively identified all patients with PRES who were admitted to Severance Hospital and consulted with the Department of Neurology between 2001 and 2013 and the subgroup of these patients who subsequently developed epilepsy. We also describe clinical features of patients who were not treated with PRES as inpatients at our center but who presented later with post-PRES epilepsy during the study period. We studied clinical characteristics during the acute symptomatic phase of PRES and after the development of epilepsy. During the study period 102 patients were treated at our center during the acute phase of PRES. Four of these patients (3.9%) subsequently developed epilepsy. Two additional patients with a history of PRES presented to our hospital after the acute phase of their illness with post-PRES epilepsy. During the acute phase, five of six patients had acute symptomatic seizures and four had convulsive or nonconvulsive status epilepticus (SE). Acute phase MRI showed cytotoxic edema in five patients, and follow-up MRI showed focal atrophic changes including hippocampal sclerosis in four. Presumptive epileptogenic foci were located in the left-side temporal, parietal and occipital lobes, corresponding to the regions that showed cytotoxic edema or severe vasogenic edema as well as with the location or lateralization of EEG abnormalities during the acute phase. Our findings indicate a small but not insignificant risk for the development of epilepsy after PRES. The presence of cytotoxic edema and severe, acute symptomatic seizures, such as SE suggests irreversible brain damage and may predict the development of epilepsy. Copyright © 2015 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

  1. Management and outcomes of malignant posterior reversible encephalopathy syndrome.

    PubMed

    Akins, Paul T; Axelrod, Yekaterina; Silverthorn, James W; Guppy, Kern; Banerjee, Amit; Hawk, Mark W

    2014-10-01

    Recognition of severe forms of posterior reversible encephalopathy syndrome (PRES) has improved. Management of these patients remains challenging, particularly in patients with the combination of edema and hemorrhage. A prospective inpatient neuro-intensive care database was queried for patients with PRES. Malignant PRES was diagnosed by clinical assessments (GCS less than 8 and clinical decline despite standard medical management for elevated intracranial pressure) and radiographic criteria (edema with associated mass effect; brain hemorrhage exerting mass effect; effacement of basal cisterns, transtentorial, tonsillar, or uncal herniation). Malignant PRES was defined as: radiology studies consistent with PRES; GCS less than 8; and clinical decline despite standard elevated intracranial pressure management. Five cases were identified over a 4 year interval. The following contributing conditions were also present: chemotherapy (1), systemic lupus erythematosis (2), pregnancy (1), and methamphetamines (1). Neurocritical care interventions included: hyperosmolar therapy (5), anticonvulsants (5), management of coagulopathy (5), and ventilatory support (5). Neurosurgical interventions included: craniectomy (5), hematoma evacuation (3), and external ventricular drain (4). Brain biopsy was performed in 5 patients and was negative for vasculitis, demyelinating disease, tumor, or infection. Cyclophosphamide was administered to the two patients with SLE. With long-term follow up, all patients achieved good functional outcomes (modified Rankin score 1-2). In contrast to historical reports of high mortality rates (16-29%) for severe and hemorrhagic PRES variants, we had no fatalities and observed favorable functional outcomes with intracranial pressure monitoring and craniectomy for malignant PRES cases who fail medical ICP management. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Posterior reversible encephalopathy syndrome secondary to blood transfusion.

    PubMed

    Singh, Karanbir; Gupta, Rajesh; Kamal, Haris; Silvestri, Nicholas J; Wolfe, Gil I

    2015-03-01

    The appearance of posterior reversible encephalopathy syndrome (PRES) after blood transfusion is rare and has only been reported in three patients to our knowledge. We report a fourth patient with PRES secondary to blood transfusion. A 36-year-old woman with a history of menorrhagia presented to the emergency department with severe fatigue. She had a hemoglobin of 1.7 g/dl and received four units of red blood cells over 15 hours. On day 6 post-transfusion she returned with confusion, headache and a generalized tonic-clonic seizure. The MRI of her brain was consistent with PRES. The following day her confusion worsened, repeat MRI of the brain showed new T2-weighted lesions. Over next 10 days her mental status gradually improved close to her baseline. A repeat MRI of the brain showed resolution of the T2-weighted lesions. The clinical presentation, radiological findings and disease progression in our patient was consistent with PRES. Other than the blood transfusions, there were no apparent risk factors for PRES. The prior three patients with post-transfusion PRES have been reported in middle-aged women with uterine fibroids. It is suspected that these patients have a subacute to chronic anemic state due to ongoing menorrhagia. It is interesting to note that no cases of PRES post-transfusion have been reported in the setting of acute blood loss, such as from trauma. It is postulated that an abrupt increase in hemoglobin causes a rapid rise in blood viscosity and loss of hypoxic vasodilation. Subsequent endothelial damage and brain capillary leakage results in PRES. This constellation of changes may not occur after transfusion in patients with more acute blood loss.

  3. Hemorrhage in posterior reversible encephalopathy syndrome: imaging and clinical features.

    PubMed

    Hefzy, H M; Bartynski, W S; Boardman, J F; Lacomis, D

    2009-08-01

    Hemorrhage is known to occur in posterior reversible encephalopathy syndrome (PRES), but the characteristics have not been analyzed in detail. The purpose of this study was to evaluate the imaging and clinical features of hemorrhage in PRES. Retrospective assessment of 151 patients with PRES was performed, and 23 patients were identified who had intracranial hemorrhage at toxicity. Hemorrhage types were identified and tabulated, including minute focal hemorrhages (<5 mm), sulcal subarachnoid hemorrhage, and focal hematoma. Clinical features of hemorrhage and nonhemorrhage PRES groups were evaluated, including toxicity blood pressure, coagulation profile/platelet counts, coagulation-altering medication, and clinical conditions associated with PRES. Toxicity mean arterial pressure (MAP) groups were defined as normal (<106 mm Hg), mildly hypertensive (106-116 mm Hg), or severely hypertensive (>116 mm Hg). The overall incidence of hemorrhage was 15.2%, with borderline statistical significance noted between the observed clinical associations (P = .07). Hemorrhage was significantly more common (P = .02) after allogeneic bone marrow transplantation (allo-BMT) than after solid-organ transplantation. The 3 hemorrhage types were noted with equal frequency. A single hemorrhage type was found in 16 patients, with multiple types noted in 7. Patients undergoing therapeutic anticoagulation were statistically more likely to develop hemorrhage (P = .04). No difference in hemorrhage incidence was found among the 3 blood pressure subgroups (range, 14.9%-15.9%). Three distinct types of hemorrhage (minute hemorrhage, sulcal subarachnoid hemorrhage, hematoma) were identified in PRES with equal frequency. The greatest hemorrhage frequency was seen after allo-BMT and in patients undergoing therapeutic anticoagulation. Hemorrhage rate was independent of the toxicity blood pressure.

  4. 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.

  5. Reversible posterior encephalopathy syndrome associated with micronodular adrenocortical disease and Cushing syndrome.

    PubMed

    Lodish, Maya; Patronas, Nicholas J; Stratakis, Constantine A

    2010-01-01

    We report a 6-year-old girl with ACTH-independent Cushing syndrome secondary to bilateral adrenal hyperplasia; she presented with hypertension and seizures, and magnetic resonance imaging shows changes consistent with posterior reversible encephalopathy syndrome.

  6. Reversible Cerebral Vasoconstriction Syndrome and Posterior Reversible Encephalopathy Syndrome Presenting with Deep Intracerebral Hemorrhage in Young Women

    PubMed Central

    Lee, Won Jae; JO, Kyung-Il; Kim, Jong-Soo; Hong, Seung-Chyul

    2015-01-01

    Reversible cerebral vasoconstriction syndrome (RCVS) is a group of syndromes characterized by reversible segmental constriction of cerebral arteries. Posterior reversible encephalopathy syndrome (PRES) is another clinical-radiologic syndrome characterized by reversible, posterior-predominant brain edema. Although the exact causes of these reversible syndromes are poorly understood, these entities may share some common pathophysiologic elements leading to hemorrhagic strokes and rarely, deep intracerebral hemorrhage (ICH). Recent studies have suggested that endothelial dysfunction is a common pathophysiologic factor associated with these syndromes. We report on two young female patients who presented with deep ICH and were later diagnosed as RCVS and PRES. Both patients suffered from vasoconstriction and delayed ischemic stroke. Early detection of distinguishing clinical-radiologic features associated with these reversible syndromes and removing triggers would facilitate successful treatment with no complications. PMID:26523259

  7. Assessment of Noninvasive Regional Brain Oximetry in Posterior Reversible Encephalopathy Syndrome and Reversible Cerebral Vasoconstriction Syndrome.

    PubMed

    Chung, David Y; Claassen, Jan; Agarwal, Sachin; Schmidt, J Michael; Mayer, Stephan A

    2016-07-01

    Posterior reversible encephalopathy syndrome (PRES) leads to small- and large-vessel circulatory dysfunction. While aggressive lowering of elevated blood pressure is the usual treatment for PRES, excessive blood pressure reduction may lead to ischemia or infarction, particularly when PRES is accompanied by reversible cerebral vasoconstriction syndrome (RCVS). Regional cerebral oximetry using near-infrared spectroscopy is a noninvasive modality that is commonly used intraoperatively and in intensive care settings to monitor regional cerebral oxygenation (rSO2) and may be useful in guiding treatment in select cases of PRES and RCVS. We report a case of a patient with PRES complicated by infarction and RCVS where the optimal blood pressure management was unclear. A decision was made to decrease blood pressure which resulted in an improved neurological examination and increase in rSO2 from 40% to 55% in at-risk brain. Infarcted brain as determined by diffusion-weighted magnetic resonance imaging and computed tomography perfusion imaging showed no change in rSO2 during the same time period. Furthermore, there was a qualitative change in the rSO2-mean arterial pressure (MAP) relationship, suggesting an alteration in cerebrovascular autoregulation as a result of lowering blood pressure. Regional cerebral oximetry can provide valuable diagnostic feedback in complicated cases of PRES and RCVS. © The Author(s) 2016.

  8. Antepartum reversible cerebral vasoconstriction syndrome with pre-eclampsia and reversible posterior leukoencephalopathy.

    PubMed

    Tanaka, Kei; Matsushima, Miho; Matsuzawa, Yukiko; Wachi, Yuichi; Izawa, Tomoko; Sakai, Keiji; Kobayashi, Yoichi; Iwashita, Mitsutoshi

    2015-11-01

    Reversible cerebral vasoconstriction syndrome (RCVS) is characterized by severe headache and diffuse segmental constriction of the cerebral arteries that resolves spontaneously within a few months. Pregnancy is one of the precipitating factors of RCVS and most of the reported cases occurred in the post-partum period. We report a case of RCVS that occurred in a pregnant women with pre-eclampsia during her antepartum period. A 34-year-old woman in full-term pregnancy presented with a severe and acute headache. Magnetic resonance angiography (MRA) showed multiple segmental constrictions of the cerebral arteries. Magnetic resonance imaging revealed a high-intensity lesion in the left occipital lobe, consistent with reversible posterior leukoencephalopathy syndrome, on fluid attenuated inversion recovery sequences. The case was also complicated by severe pre-eclampsia and the patient underwent emergency cesarean section. Although her symptoms resolved rapidly, MRA revealed new lesions of arterial constriction 4 days after onset. The vasoconstriction completely resolved on MRA after 10 days and the patient was discharged without neurological sequelae. © 2015 Japan Society of Obstetrics and Gynecology.

  9. Incidence of posterior reversible encephalopathy syndrome in eclamptic and patients with preeclampsia with neurologic symptoms.

    PubMed

    Mayama, Michinori; Uno, Kaname; Tano, Sho; Yoshihara, Masato; Ukai, Mayu; Kishigami, Yasuyuki; Ito, Yasuhiro; Oguchi, Hidenori

    2016-08-01

    Posterior reversible encephalopathy syndrome is observed frequently in patients with eclampsia; however, it has also been reported in some patients with preeclampsia. The aim of this study was to determine the incidence of posterior reversible encephalopathy syndrome in patients with preeclampsia and eclampsia and to assess whether these 2 patient groups share similar pathophysiologic backgrounds by comparing clinical and radiologic characteristics. This was a retrospective cohort study of 4849 pregnant patients. A total of 49 patients with eclampsia and preeclampsia and with neurologic symptoms underwent magnetic resonance imaging and magnetic resonance angiography; 10 patients were excluded from further analysis because of a history of epilepsy or dissociative disorder. The age, parity, blood pressure, and routine laboratory data at the onset of symptoms were also recorded. Among 39 patients with neurologic symptoms, 12 of 13 patients with eclampsia (92.3%) and 5 of 26 patients with preeclampsia (19.2%) experienced the development of posterior reversible encephalopathy syndrome. Whereas age and blood pressure at onset were not significantly different between patients with and without encephalopathy, hematocrit, serum creatinine, aspartate transaminase, alanine transaminase, and lactate dehydrogenase values were significantly higher in patients with posterior reversible encephalopathy syndrome than in those without magnetic resonance imaging abnormalities. In contrast, patients with eclampsia with posterior reversible encephalopathy syndrome did not show any significant differences in clinical and laboratory data compared with patients with preeclampsia with posterior reversible encephalopathy syndrome. In addition to the parietooccipital regions, atypical regions (such as the frontal and temporal lobes), and basal ganglia were also involved in patients with eclampsia and patients with preeclampsia with posterior reversible encephalopathy syndrome. Finally

  10. Posterior Reversible Encephalopathy Syndrome in a Postpartum Preeclamptic Woman without Seizure

    PubMed Central

    Ural, Ülkü Mete; Balik, Gülsah; Şentürk, Şenol; Üstüner, Işık; Çobanoğlu, Uğur; Şahin, Figen Kır

    2014-01-01

    Posterior reversible encephalopathy syndrome (PRES) is a cliniconeuroradiological entity presenting with headache, confusion, visual disturbances or blindness, and seizures. Parieto-occipital white matter changes due to vasogenic oedema can be observed on imaging modalities. It rarely occurs without seizures and after delivery. We report a 33-year-old multigravida with a history of preeclampsia in term pregnancy complicated by PRES without seizures at the postpartum period. Clinical improvement with complete resolution without any complications was observed on the 6th day after delivery. Posterior reversible encephalopathy syndrome is reversible when early diagnosis is established and appropriate treatment is started without delay. PMID:24592342

  11. Posterior Reversible Encephalopathy Syndrome in a Bone Marrow Transplant Patient: A Complication of Immunosuppressive Drugs?

    PubMed

    Hossain, Mohammad A; Jehangir, Waqas; Nai, Qiang; Jessani, Naureen; Khan, Rafay; Yousif, Abdalla; Sen, Shuvendu

    2015-08-01

    Posterior reversible encephalopathy is a complex but well-recognized clinical and radiological entity associated with a variety of benign and malignant conditions including hypertensive encephalopathy, eclampsia, renal failure and immunosuppressive drugs. The pathogenesis is incompletely understood, although it seems to be related to the breakthrough of auto-regulation and endothelial dysfunction. The clinical syndromes typically involve headache, altered mental status, seizures, visual disturbance and other focal neurological signs and radiographically reversible vasogenic subcortical edema without infarction. Here, we report a case of posterior reversible encephalopathy syndrome in a patient with chronic myeloid leukemia who received allogenic bone marrow transplantation (allo-BMT) and immunosuppressive drugs.

  12. Posterior Reversible Encephalopathy Syndrome in a Postpartum Preeclamptic Woman without Seizure.

    PubMed

    Ural, Ulkü Mete; Balik, Gülsah; Sentürk, Senol; Ustüner, Işık; Cobanoğlu, Uğur; Sahin, Figen Kır

    2014-01-01

    Posterior reversible encephalopathy syndrome (PRES) is a cliniconeuroradiological entity presenting with headache, confusion, visual disturbances or blindness, and seizures. Parieto-occipital white matter changes due to vasogenic oedema can be observed on imaging modalities. It rarely occurs without seizures and after delivery. We report a 33-year-old multigravida with a history of preeclampsia in term pregnancy complicated by PRES without seizures at the postpartum period. Clinical improvement with complete resolution without any complications was observed on the 6th day after delivery. Posterior reversible encephalopathy syndrome is reversible when early diagnosis is established and appropriate treatment is started without delay.

  13. Reversible cerebral vasoconstriction syndrome and posterior reversible encephalopathy syndrome associated with intracranial hypotension.

    PubMed

    Feil, Katharina; Forbrig, Robert; Thaler, Franziska S; Conrad, Julian; Heck, Suzette; Dorn, Franziska; Pfister, Hans-Walter; Straube, Andreas

    2017-02-01

    Reversible cerebral vasoconstriction syndrome (RCVS) and posterior reversible encephalopathy syndrome (PRES) are both rare disorders. The pathophysiology of both diseases is not yet fully understood. We report the unique case of a 19-year-old comatose woman who was brought to the ER after a series of generalized tonic-clonic seizures 6 days post peridural anesthesia for cesarean section. Vital signs and initial laboratory testing including urine analysis and drug screening were unremarkable. Initial cranial CT scan showed an acute small subdural hematoma (17 mm length × 6 mm width × 30 mm height), cerebral edema with slit ventricles, and slight cerebellar tonsillar herniation as signs of intracranial hypotension. CT angiography depicted narrowing of the proximal intracranial vessels consistent with RCVS. MR imaging was also suggestive of both intracranial hypotension and RCVS and showed, in addition, vasogenic edema consistent with PRES. An extensive CSF leakage involving T1 to L2/L3 was confirmed by spinal MRI. The patient underwent conservative therapy for intracranial hypotension (e.g., head-down position) as well as epidural blood patch, which led to regression of the clinical symptoms within a few days. Follow-up MRI showed complete resolution of all radiological changes. In summary, our patient developed clinical and neuroradiological signs of intracranial hypotension and a combination of PRES and RCVS associated with a CSF leakage caused by peridural anesthesia; by treating the intracranial hypotension, the other syndromes resolved. From a clinical point of view, it is important to look for CSF leakage as a treatable possible cause of PRES and/or RCVS triggered by intracranial hypotension as in our patient postpartum. Moreover, it is vital to obtain a good history as, in cases of suspected CSF leakage with classic postural headache, a recent spinal/cranial procedure is typically present.

  14. Post-streptococcal glomerulonephritis leading to posterior reversible encephalopathy syndrome: a case report.

    PubMed

    Adikari, Madura; Priyangika, Dilani; Marasingha, Indika; Thamotheram, Sharmila; Premawansa, Gayani

    2014-09-13

    Posterior reversible encephalopathy syndrome is a clinical radiographic syndrome of heterogeneous etiologies. Developing hypertensive encephalopathy following post-streptococcal glomerulonephritis is a known but uncommon manifestation and developing posterior reversible encephalopathy syndrome in such a situation is very rare. We report a case with contrast-enhanced computed tomography and magnetic resonance imaging findings of posterior reversible encephalopathy syndrome in the background of acute post-streptococcal glomerulonephritis. A thirteen-year-old Sri Lankan boy presented with a focal fit by way of secondary generalization with duration of 10 minutes, and developed 2 similar fits subsequently following admission. He later developed severe hypertension with evidence of glomerulonephritis, which was diagnosed as acute post-streptococcal glomerulonephritis. A contrast-enhanced computed tomography imaging of brain done on day-3 revealed non-enhancing low-attenuating areas in fronto-parietal regions. A T2 weighted film of magnetic resonance imaging was done on day-10 of the admission and found to have linier sub-cortical hyper intensities in both parietal regions which were compatible with the radiological diagnosis of posterior reversible encephalopathy syndrome. Post-streptococcal glomerulonephritis is an important cause of acute nephritic syndrome especially in children. This case report illustrates a rare association of posterior reversible encephalopathy syndrome in a patient with post-streptococcal glomerulonephritis.

  15. Posterior reversible encephalopathy and cerebral vasoconstriction in a patient with hemolytic uremic syndrome.

    PubMed

    Agarwal, Rajkumar; Davis, Cresha; Altinok, Deniz; Serajee, Fatema J

    2014-05-01

    We report a patient with hemolytic uremic syndrome who presented with radiological manifestations suggestive of posterior reversible encephalopathy syndrome and reversible cerebral vasoconstriction syndrome. A 13-year-old girl presented with fever and bloody diarrhea and progressed to develop hemolytic uremic syndrome. She subsequently developed encephalopathy, aphasia, and right-sided weakness. Brain magnetic resonance imaging showed presence of vasogenic edema in the left frontal lobe, in addition to T2 and fluid-attenuated inversion recovery changes in white matter bilaterally, compatible with posterior reversible encephalopathy syndrome. Magnetic resonance angiography showed beading of the cerebral vessels. Neurological deficits reversed 8 days after symptom onset, with resolution of the beading pattern on follow-up magnetic resonance angiography after 3 weeks, suggesting reversible cerebral vasoconstriction syndrome. Both posterior reversible encephalopathy syndrome and reversible cerebral vasoconstriction syndrome may represent manifestations of similar underlying pathophysiologic mechanisms. Recognition of the co-existence of these processes in patients with hemolytic uremic syndrome may aid in judicious management of these patients and avoidance of inappropriate therapeutic interventions. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. 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.

  17. Reversible cerebral vasoconstriction syndrome and posterior reversible encephalopathy syndrome in a boy with Loeys-Dietz syndrome.

    PubMed

    Akazawa, Yohei; Inaba, Yuji; Hachiya, Akira; Motoki, Noriko; Matsuzaki, Satoshi; Minatoya, Kenji; Morisaki, Takayuki; Morisaki, Hiroko; Kosaki, Kenjiro; Kosho, Tomoki; Koike, Kenichi

    2015-10-01

    Loeys-Dietz syndrome (LDS) is an autosomal dominant connective tissue disorder, caused by heterozygous mutations in TGFBR1 or TGFBR2 and characterized by vascular complications (cerebral, thoracic, and abdominal arterial aneurysms and/or dissections) and skeletal manifestations. We here report the first patient with LDS presenting with reversible cerebral vasoconstriction syndrome (RCVS), a clinico-radiological condition characterized by recurrent thunderclap headaches, with or without neurological symptoms, and reversible vasoconstriction of cerebral arteries. The patient was a 9-year-old boy with a heterozygous TGFBR2 mutation, manifesting camptodactyly, talipes equinovarus, and lamboid craniosynostosis. He complained of severe recurrent headaches 2 months after total aortic replacement for aortic root dilatation and a massive Stanford type B aortic dissection. A thoracic CT scan revealed a left subclavian artery dissection. Brain MRI and MRA detected bilateral internal carotid artery constriction along with a cortical subarachnoid hemorrhage without intracranial aneurysms. Subsequently, he developed visual disturbance and a generalized seizure associated with multiple legions of cortical and subcortical increased signals including the left posterior lobe, consistent with posterior reversible encephalopathy syndrome (PRES), a condition characterized by headaches, visual disorders, seizures, altered mentation, consciousness disturbances, focal neurological signs, and vasogenic edema predominantly in the white matter of the posterior lobe. Vasoconstriction of the internal carotid artery was undetectable 2 months later, and he was diagnosed as having RCVS. Endothelial dysfunction, associated with impaired TGF-β signaling, might have been attributable to the development of RCVS and PRES. © 2015 Wiley Periodicals, Inc.

  18. Posterior Reversible Encephalopathy Syndrome with Extensive Deep White Matter Lesions Including the Temporal Pole

    PubMed Central

    Ohira, Junichiro; Mori, Nobuyuki; Kajikawa, Shunsuke; Nakamura, Takeshi; Arisato, Tetsuya; Takahashi, Makio

    2016-01-01

    Posterior reversible encephalopathy syndrome (PRES) typically affects the posterior subcortical white matter. We report the case of a 55-year-old man with atypical PRES, who had malignant hypertension and renal dysfunction. Magnetic resonance imaging of the brain revealed extensive vasogenic edema in the deep white matter including the temporal pole, as well as in the brainstem and cerebellum. Antihypertensive therapy and hemodialysis contributed to both clinical and radiological improvement. Involvement of the deep white matter including the temporal pole, which is rarely affected in an ischemic stroke, should be recognized as a potential sign of PRES. PMID:27904123

  19. Multiple cavitations in posterior reversible leukoencephalopathy syndrome associated with hemolytic-uremic syndrome.

    PubMed

    Fujii, Katsunori; Matsuo, Kaoru; Takatani, Tomozumi; Uchikawa, Hideki; Kohno, Yoichi

    2012-04-01

    We describe a 4-year-old boy with posterior reversible leukoencephalopathy syndrome associated with hemolytic-uremic syndrome. He exhibited bloody stool by Escherichia coli O157: H7 infection with acute renal failure. He subsequently presented high blood pressure, followed by visual disturbance and loss of consciousness. Brain MRI revealed bilateral occipital high intensities by T2-weighted images and high value by apparent diffusion coefficient map, thus we made a diagnosis of posterior reversible leukoencephaly syndrome associated with hemolytic-uremic syndrome. In spite of immediate blood pressure control, occipital lesions developed day by day, resulting in multiple subcortical cavitations. Although posterior reversible leukoencephalopathy syndrome is originally characterized by reversible vasogenic edema, this case rarely resulted in irreversible changes with cystic formation. We concluded that precipitating factors, i.e., clotting abnormalities, Shiga toxin, vasospasms and endothelial dysfunction might have synergistically induced irreversible brain infarcts, and caused unusual cavitations. Copyright © 2011 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

  20. Posterior reversible encephalopathy syndrome in children: its high prevalence and more extensive imaging findings.

    PubMed

    Ishikura, Kenji; Ikeda, Masahiro; Hamasaki, Yuko; Hataya, Hiroshi; Shishido, Seiichirou; Asanuma, Hiroshi; Nishimura, Gen; Hiramoto, Ryugo; Honda, Masataka

    2006-08-01

    Posterior reversible encephalopathy syndrome is a distinctive clinicoradiological entity observed in a variety of clinical settings, including pediatric patients. A greater prevalence of this syndrome has been suggested in kidney transplant recipients and patients with kidney disease. Although usually considered benign and reversible, characteristics of this syndrome in pediatric patients remain obscure. The objective of the present study involved disclosing details of imaging findings, as well as the clinical course and prevalence of the syndrome in this field. We investigated kidney transplant recipients and pediatric patients with kidney disease in our institution from 1990 to 2004. For these patients, clinical course, imaging findings, blood pressure, concurrent medical illnesses, and administrative condition of calcineurin inhibitors were analyzed. Twenty cases of posterior reversible encephalopathy syndrome were investigated in patients ranging in age from 1.9 to 18.3 years. In most patients, radiological abnormalities extended to the gray matter (17 of 20 patients), frontal and temporal lobes, and even the cerebellum (16 patients). Of 177 kidney transplant recipients (cyclosporine, 127 patients; tacrolimus, 50 patients), 6 patients administered cyclosporine (4.7%) and 4 patients administered tacrolimus (8.0%) developed the syndrome after transplantation. Posterior reversible encephalopathy syndrome should be suspected in pediatric kidney transplant recipients and patients with kidney disease if they have a sudden episode of neurological symptoms, even if imaging findings are not restricted to the subcortical white matter of the occipital region.

  1. The reverse Segond fracture: not associated with knee dislocation and rarely with posterior cruciate ligament tear.

    PubMed

    Peltola, Erno K; Lindahl, Jan; Koskinen, Seppo K

    2014-06-01

    The aims of this study were to assess the incidence of reverse Segond fracture, to examine the associated ligamentous injuries, and to examine how often reverse Segond fracture coexists with a knee dislocation. At a level 1 trauma center, an 11-year period of emergency department multidetector-row computed tomography (MDCT) examinations for knee trauma was evaluated for reverse Segond and Segond fractures. Surgical findings served as the reference standard for intra-articular injuries. The hospital discharge register was searched for the diagnosis of knee dislocation from August 2000 through the end of August 2011. A total of 1,553 knee MDCT examinations were evaluated. Ten patients with a reverse Segond fracture were found, comprising 0.64 % of emergency room acute knee trauma MDCT examinations. Seven patients who had a reverse Segond fracture were operated: Three had an avulsion fracture of the anterior cruciate ligament, one had an avulsion fracture of posterior cruciate ligament, two had a lateral meniscal tear, and two had a medial collateral ligament tear. The ratio of reverse Segond fractures to Segond fractures was 1:4. None of the 71 knee dislocation patients had a reverse Segond fracture. Reverse Segond fracture is a rare finding even in a level 1 trauma center. Cruciate ligament injuries appear to be associated with avulsion fracture, but every patient does not have PCL injury, as previously reported. Our results do not support the association of knee dislocation with reverse Segond fracture.

  2. Acute Posterior Shoulder Dislocation with Reverse Hill-Sachs Lesion of the Epiphyseal Humeral Head

    PubMed Central

    Patrizio, Luigi; Sabetta, Ettore

    2011-01-01

    Posterior dislocation of the shoulder is an unfrequent event that often occurs as a consequence of a direct trauma or epileptic crisis. Frequently the posterior dislocations are misunderstood, so they become chronic lesions. We reported a case of an acute posterior left shoulder dislocation with lesser tuberosity fracture and reverse Hill-Sachs lesions which involved more than 25% of the articular surface of the humeral head, in a 57-old-year man with right hemiparesis. We performed a synthesis of the lesser tuberosity with a screw, and we restored the shape of the humeral head with allograft. We achieved a good result that allows the patient to be able to do his previous activities of daily living. PMID:22084780

  3. Acute posterior shoulder dislocation with reverse hill-sachs lesion of the epiphyseal humeral head.

    PubMed

    Patrizio, Luigi; Sabetta, Ettore

    2011-01-01

    Posterior dislocation of the shoulder is an unfrequent event that often occurs as a consequence of a direct trauma or epileptic crisis. Frequently the posterior dislocations are misunderstood, so they become chronic lesions. We reported a case of an acute posterior left shoulder dislocation with lesser tuberosity fracture and reverse Hill-Sachs lesions which involved more than 25% of the articular surface of the humeral head, in a 57-old-year man with right hemiparesis. We performed a synthesis of the lesser tuberosity with a screw, and we restored the shape of the humeral head with allograft. We achieved a good result that allows the patient to be able to do his previous activities of daily living.

  4. [Prolonged cerebral salt wasting following craniopharyngioma surgery and posterior reversible encephalopathy syndrome: a case report].

    PubMed

    Ohtonari, Tatsuya; Hashimoto, Masanori; Urasaki, Eiichiro; Yokota, Akira; Araki, Shunsuke; Asayama, Koutaro; Shirahata, Akira

    2005-01-01

    A 9-year-old boy was admitted to our hospital with daytime urinary incontinence for the past one year. MRI showed craniopharyngioma occupying the third ventricle. The tumor was excised by interhemispheric approach. Because hyponatremia and polyuria with high renal loss of sodium were observed on postoperative day 3, hydrocortisone and DDAVP were replaced. On postoperative day 24, successive general convulsions and hyponatremia recurred, and MRI FLAIR imaging showed marked brain edema in the bilateral parieto-occipital lobes. This finding disappeared late in the course of treatment, and the case was diagnosed as posterior reversible encephalopathy syndrome. The pathophysiology of cerebral salt wasting and posterior reversible encephalopathy syndrome in a craniopharyngioma patient are also discussed in the article.

  5. 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

  6. Central-Variant Posterior Reversible Encephalopathy due to Sulfasalazine: A Case Report.

    PubMed

    Ocek, Levent; Sener, Ufuk; Demirtas, Burcu S; Ozcelik, Metin M; Oztekin, Ozgur; Zorlu, Yasar

    2015-01-01

    To report a rare case with central-variant posterior reversible encephalopathy syndrome due to sulfasalazine. A 55-year-old female patient presented with seizure and acute-onset hemiparesia. Thirty days earlier, treatment with sulfasalazine was commenced in response to a diagnosis of psoriatic arthritis. Laboratory examinations were normal. Brain magnetic resonance imaging showed symmetric edema within basal ganglia and thalami with sparing of the cerebral cortices. After stopping the treatment of sulfasalazine, clinical and radiological findings regressed dramatically. This was a case of central-variant posterior reversible encephalopathy syndrome due to sulfasalazine, and atypical imaging findings should be kept in mind for early diagnosis. © 2015 S. Karger AG, Basel.

  7. Severe Posterior Reversible Encephalopathy in Pheochromocytoma: Importance of Susceptibility-Weighted MRI

    PubMed Central

    Alkan, Alpay; Aralasmak, Ayse; Kocakoc, Ercan

    2013-01-01

    Pheochromocytoma is a rare cause of hypertension in children. Hypertension is one of the common reasons of posterior reversible encephalopathy. Intracerebral hemorrhage is a serious and unexpected complication of hypertensive encephalopathy due to pheochromocytoma, and very rarely seen in the childhood. Intracerebral hemorrhages should be searched if there are hypertensive reversible signal changes on the brain. Susceptibility weighted imaging (SWI) is a more sensitive method than conventional MRI when demonstrating cerebral microhemorrhagic foci. This is the first report of SWI findings on intracerebral hemorrhages in basal ganglia, brain stem and periventricular white matter due to hypertensive encephalopathy in a child with pheochromocytoma. PMID:24043985

  8. [The course of early neurological rehabilitation in a patient with severe posterior reversible encephalopathy syndrome].

    PubMed

    Gdynia, H J; Ampatzis, G; Diaconescu, A; Nowak, D A; Dabitz, R; Pfefferkorn, T

    2014-12-01

    Posterior reversible encephalopathy syndrome (PRES) is widely held to be a benign and potentially reversible disease. However, severe cases have been described in the literature. Data on the long-term outcome of these severe cases are scarce. Furthermore, there are no data focusing on potential benefits of neurological early rehabilitation in these patients. Here we present the clinical picture, neuroimaging features, rehabilitative course and long-term outcome of a patient with severe PRES who underwent early neurological rehabilitation. © Georg Thieme Verlag KG Stuttgart · New York.

  9. [Posterior reversible encephalopathy syndrome: description of a case in the setting of severe infection].

    PubMed

    Zeppa, Pio; Fonio, Paolo; Giganti, Melchiore; Cotroneo, Antonio Raffaele; Genovese, Eugenio Annibale; Stabile Ianora, Antonio Amato

    2012-11-01

    Posterior reversible encephalopathy syndrome (PRES) is a well recognized neurotoxic state coupled with a unique neuroradiological appearance. This syndrome is associated with a broad spectrum of complex conditions (preeclampsia/eclampsia, bone marrow/organ transplantation, chemotherapy, autoimmune disease). We report the case of a female patient who developed PRES in the setting of severe infection, and we discuss the possible mechanisms underlying the development of cerebral edema by describing the inherent neuroradiological features.

  10. Dialysis disequilibrium leading to posterior reversible encephalopathy syndrome in chronic renal failure.

    PubMed

    Sengupta, Pratim; Biswas, Sumanta

    2016-11-01

    Dialysis disequilibrium syndrome is a neurological adverse effect of acute hemodialysis in advanced uremic patients. Dialysis disequilibrium has a wide spectrum of clinical manifestations starting from subtle uneasiness, confusion, to florid and complex life threatening neurological deficit. In this case study, we present a patient who developed sudden cortical blindness following hemodialysis due to posterior reversible encephalopathy, which is a rare presentation of dialysis disequilibrium syndrome.

  11. Reversible Posterior Leukoencephalopathy in a Venomous Snake (Bothrops asper) Bite Victim

    PubMed Central

    Delgado, Miguel E.; Del Brutto, Oscar H.

    2012-01-01

    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

  12. 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.

  13. 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.

  14. [PRES (Posterior Reversible Encephalopathy Syndrome): potential complication of hypertensive crisis. Case report and literature review].

    PubMed

    Vergura, Michele; Prencipe, Michele; Del Giudice, Antonio Maria; Grifa, Rachele; Miscio, Filomena; Pennelli, Anna Maria; Popolizio, Teresa; Simeone, Anna; Ferrara, Mariangela; Leone, Maurizio; Aucella, Filippo

    2017-04-01

    Posterior reversible encephalopathy syndrome (PRES) is a clinical-radiological syndrome, usually reversible, characterized by vasogenic oedema in cerebral posterior regions in patients with autoimmune diseases, nephropathies, hypertensive crisis, eclampsia and exposure to cytotoxic drugs. The main symptoms are: headache, nausea, vomiting, seizures, visual disturbance and altered consciousness. Complications as cerebral hemorrhage and recurrences are rare. We describe a case of a 65 years old woman, affected by chronic kidney disease, recently exacerbated, diabetes and hypertension in treatment, who showed an heterogeneous clinical presentation with vomiting, headache, blurred vision and impaired consciousness during an episode of acute hypertension. After an adjustement of the antihypertensive treatment we observed a regression of symptoms in one week. FLAIR sequences on MRI showed cerebral bilateral vasogenic oedema in posterior regions, typical for PRES. This case was suggestive for PRES and a prompt adjustement of the antihypertensive treatment was critical for clinical recovery. Brain MRI was crucial for diagnosis. It is important for clinicians to recognize PRES as a possible complication of renal disease and hypertensive crisis. Copyright by Società Italiana di Nefrologia SIN, Rome, Italy.

  15. Posterior reversible encephalopathy syndrome--Insight into pathogenesis, clinical variants and treatment approaches.

    PubMed

    Granata, Guido; Greco, Antonio; Iannella, Giannicola; Granata, Massimo; Manno, Alessandra; Savastano, Ersilia; Magliulo, Giuseppe

    2015-09-01

    Posterior reversible encephalopathy syndrome is a rare clinicoradiological entity characterized by typical MRI findings located in the occipital and parietal lobes, caused by subcortical vasogenic edema. It was first described as a distinctive syndrome by Hinchey in 1996. Etiopathogenesis is not clear, although it is known that it is an endotheliopathy of the posterior cerebral vasculature leading to failed cerebral autoregulation, posterior edema and encephalopathy. A possible pathological activation of the immune system has been recently hypothesized in its pathogenesis. At clinical onset, the most common manifestations are seizures, headache and visual changes. Besides, tinnitus and acute vertigo have been frequently reported. Symptoms can be reversible but cerebral hemorrhage or ischemia may occur. Diagnosis is based on magnetic resonance imaging, in the presence of acute development of clinical neurologic symptoms and signs and arterial hypertension and/or toxic associated conditions with possible endotheliotoxic effects. Mainstay on the treatment is removal of the underlying cause. Further investigation and developments in endothelial cell function and in neuroimaging of cerebral blood flow are needed and will help to increase our understanding of pathophysiology, possibly suggesting novel therapies.

  16. Recurrent posterior reversible encephalopathy syndrome in a hypertensive patient with end-stage renal disease.

    PubMed

    Ergün, Tarkan; Lakadamyali, Hatice; Yilmaz, Aynur

    2008-12-01

    Posterior reversible encephalopathy syndrome (PRES) is a clinical and radiologic entity characterized by headache, variable mental status, epilepsy, visual disturbances, and typical transient changes in the posterior cerebral perfusion. Recurrence of PRES is not common, but increasingly in recent years, studies demonstrate recurrence of this syndrome in populations with different diseases. In this report, we describe recurrent PRES in a hypertensive patient with end-stage renal disease, and discuss recurrence as the least-characterized feature of PRES. This condition can cause neurological sequelae such as persistent brain damage and epilepsy, arising from delays in diagnosis and therapy. To the best of our knowledge, this is the first report demonstrating recurrent PRES in a patient on hemodialysis for end-stage renal disease.

  17. 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. PMID:27322924

  18. 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

  19. Posterior reversible encephalopathy syndrome in a patient with hepatitis B induced type 1 membranoproliferative glomerulonephritis.

    PubMed

    Sathyanarayanan, Vishwanath; Razak, Abdul; Narayan, Girish; Prabhu, Mukhyaprana; Ramachandran, Balasubramanian; Ranjini, Kudva; Vidya, Monappa; Joshi, Kusum

    2010-12-01

    Posterior reversible encephalopathy syndrome (PRES) is a rare complication of nephrotic syndrome and corticosteroid therapy. Here, we discuss an 18 year old man with type 1 membranoproliferative glomerulonephritis (MPGN) secondary to hepatitis B infection who developed posterior leukoencephalopathy while on therapy with lamivudine and prednisone. He developed seizures and vision loss. He also had hypertension, but no sudden elevation was recorded at any time. Magnetic resonance imaging revealed patchy areas of altered signal intensity involving cortical gray and subcortical white matter in the bilateral frontoparietal regions, occipital cortices, temporal cortices and cerebellar hemispheres, and hyperintensity on T2W and FLAIR sequences. Tapering of prednisone and controlling hypertension resulted in clinical improvement within a few days, and in a month MRI was normal. Diagnosing PRES requires a high index of suspicion when treating similarly susceptible patients. PRES as a complication during the treatment of MPGN secondary to hepatitis B has, to our knowledge, never been reported previously in the literature.

  20. Linguistic history of posterior reversible encephalopathy syndrome: mirror of developing knowledge.

    PubMed

    Maizlin, Zeev V; Ghandehari, Hournaz; Maizels, Leonid; Shewchuk, Jason R; Kirby, John M; Vora, Parag; Clement, Jason J

    2011-01-01

    the term posterior reversible encephalopathy syndrome (PRES) was first proposed in 2000. Since then, the acronym PRES has become very popular in imaging and clinical literature as it is short, easy to say and remember, and neatly couples the frequent localization of neuroimaging findings along with the typical outcome of this syndrome. Another possible reason for the popularity of this acronym in clinical circles is the connotation of PRES with (elevated blood) PRESsure, as a majority of cases are believed to be associated with hypertension. However, problems exist with the interpretation and common understanding of PRES, questioning the appropriateness of "P" and "R" in the acronym. The linguistic issues related to the acronym of PRES are interesting. the aim of this work is to analyze the controversies related to the acronym of PRES. in 2006, modifying the meaning of the acronym was suggested, renaming it Potentially Reversible Encephalopathy Syndrome in order to adjust to the cases when posterior involvement is not prominent and emphasize that the reversibility is not spontaneous. This meant the creation of a backronym, where the new phrase is constructed by starting with an existing acronym. this new backronym indicates that the original acronym of PRES has become a misnomer.

  1. A Pediatric Case of Reversible Cerebral Vasoconstriction Syndrome With Similar Radiographic Findings to Posterior Reversible Encephalopathy Syndrome.

    PubMed

    Kamide, Tomoya; Tsutsui, Taishi; Misaki, Kouichi; Sano, Hiroki; Mohri, Masanao; Uchiyama, Naoyuki; Nakada, Mitsutoshi

    2017-06-01

    Reversible cerebral vasoconstriction syndrome occurs predominantly in middle-aged women. Only nine pediatric patients with this syndrome have been reported. We present a ten-year-old boy with reversible cerebral vasoconstriction syndrome with radiographic findings similar to those of posterior reversible encephalopathy syndrome (PRES). He presented with a thunderclap headache without a neurological deficit. Brain magnetic resonance angiography (MRA) revealed multifocal narrowing of the cerebral arteries, whereas magnetic resonance imaging (MRI) with diffusion-weighted imaging and fluid-attenuated inversion recovery demonstrated hyperintense lesions in the occipital lobes and the left cerebellum. The patient's symptoms resolved spontaneously after a few hours with no recurrence. MRA on the second day showed a complete normalization of the affected arteries, and MRI after one month demonstrated improvement in the abnormal findings, leading to a diagnosis of RCVS with radiographic findings similar to those of PRES. This child's findings suggests that, RCVS, with or without PRES, may occur in children who present with a thunderclap headache. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. 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.

  3. 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.

  4. An unusual presentation of a rare disease: posterior reversible encephalopathy syndrome following abdominal sepsis

    PubMed Central

    Richards, Carly R.N.; McMurray, Robert C.; Criman, Erik T.; Clark, Margaret E.; Gillern, Suzanne

    2016-01-01

    Posterior reversible encephalopathy syndrome (PRES) is an unusual disease of unknown incidence and cause. There are a wide range of associated, predisposing medical causes to include pregnancy, renal failure, immunosuppressive medication administration and hypertension. The diagnosis is made following the radiographic identification of characteristic vasogenic edema in the setting of neurologic impairment. A significant portion of patients will have long-term, if not permanent, sequelae of the disease. We present a patient who developed PRES following a hemicolectomy that was complicated by an anastomotic leak. She went on to a complete recovery following surgical treatment of the leak and supportive care. PMID:27887021

  5. Posterior reversible encephalopathy syndrome in alcoholic hepatitis: Hepatic encephalopathy a common theme

    PubMed Central

    John, Elizabeth S; Sedhom, Ramy; Dalal, Ishita; Sharma, Ranita

    2017-01-01

    Posterior reversible encephalopathy syndrome (PRES) is a neuro-radiologic diagnosis that has become more widely recognized and reported over the past few decades. As such, there are a number of known risk factors that contribute to the development of this syndrome, including volatile blood pressures, renal failure, cytotoxic drugs, autoimmune disorders, pre-eclampsia, and eclampsia. This report documents the first reported case of PRES in a patient with severe alcoholic hepatitis with hepatic encephalopathy and delves into a molecular pathophysiology of the syndrome. PMID:28127211

  6. Posterior reversible encephalopathy syndrome in alcoholic hepatitis: Hepatic encephalopathy a common theme.

    PubMed

    John, Elizabeth S; Sedhom, Ramy; Dalal, Ishita; Sharma, Ranita

    2017-01-14

    Posterior reversible encephalopathy syndrome (PRES) is a neuro-radiologic diagnosis that has become more widely recognized and reported over the past few decades. As such, there are a number of known risk factors that contribute to the development of this syndrome, including volatile blood pressures, renal failure, cytotoxic drugs, autoimmune disorders, pre-eclampsia, and eclampsia. This report documents the first reported case of PRES in a patient with severe alcoholic hepatitis with hepatic encephalopathy and delves into a molecular pathophysiology of the syndrome.

  7. Lysergic acid amide-induced posterior reversible encephalopathy syndrome with status epilepticus.

    PubMed

    Legriel, Stephane; Bruneel, Fabrice; Spreux-Varoquaux, Odile; Birenbaum, Aurelie; Chadenat, Marie Laure; Mignon, François; Abbosh, Nathalie; Henry-Lagarrigue, Matthieu; Revault D'Allonnes, Laure; Guezennec, Pierre; Troche, Gilles; Bedos, Jean Pierre

    2008-01-01

    Posterior reversible encephalopathy syndrome (PRES) is known to occur in association with several substances. However, lysergic acid amide (LSA) is not among the previously reported causes of PRES. We report on a patient with PRES presenting as convulsive status epilepticus associated with hypertensive encephalopathy after LSA ingestion. Magnetic resonance imaging was performed and catecholamine metabolites assayed. The patient achieved a full recovery after aggressive antihypertensive therapy and intravenous anticonvulsivant therapy. The clinical history, blood and urinary catecholamine levels, and response to treatment strongly suggest that PRES was induced by LSA. LSA, a hallucinogenic agent chiefly used for recreational purposes, should be added to the list of causes of PRES.

  8. Acute Intermittent Porphyria Presenting with Posterior Reversible Encephalopathy Syndrome, Accompanied by Prolonged Vasoconstriction

    PubMed Central

    Takata, Tadayuki; Kume, Kodai; Kokudo, Yohei; Ikeda, Kazuyo; Kamada, Masaki; Touge, Tetsuo; Deguchi, Kazushi; Masaki, Tsutomu

    2017-01-01

    A 20-year-old Japanese woman had an attack of acute intermittent porphyria (AIP). Magnetic resonance imaging (MRI) revealed symmetrical lesions in the cerebrum and cerebellar hemisphere, corresponding to posterior reversible encephalopathy syndrome (PRES). Our administration of heme arginate gradually improved the clinical condition associated with AIP and the level of metabolite of nitric oxide (NO), which is a vascular dilator. Repeated MRI and magnetic resonance angiography revealed exacerbated PRES, part of which showed a small infarction, accompanied by progressive vasoconstriction. These findings suggest that the recovery of NO by heme replacement alone is insufficient for preventing brain damage during an AIP attack. PMID:28321076

  9. Atypical Unilateral Posterior Reversible Encephalopathy Syndrome Mimicking a Middle Cerebral Artery Infarction.

    PubMed

    Çamlıdağ, İlkay; Cho, Yang-Je; Park, Mina; Lee, Seung Koo

    2015-01-01

    Posterior reversible encephalopathy syndrome (PRES) is usually a reversible clinical and radiological entity associated with typical features on brain MR or CT imaging. However, the not-so-uncommon atypical radiological presentations of the condition are also present and they may go unrecognised as they are confused with other conditions. Here, we report a very rare case of atypical, unilateral PRES in a 49-year-old uremic, post-transplant female patient who presented with seizures. Initial MRI showed high-grade occlusion of the left middle cerebral artery (MCA) and lesions suggestive of subacute infarction in the ipsilateral frontotemporoparietal lobe. Patient symptoms had resolved a day after the onset without any specific treatment but early follow-up CT findings suggested hemorrhagic transformation. Follow-up MRI performed 2 years later showed complete disappearence of the lesions and persisting MCA occlusion.

  10. [Posterior reversible encephalopathy in a case of late-onset eclampsia].

    PubMed

    Castrillo-Sanz, Ana; Mendoza, Amelia; Gutiérrez-Ríos, Raúl; Zamora, M Isabel; Morollón, Noemí; Rodríguez-Sanz, M Fernanda; Duarte, Jacinto

    2013-08-01

    Introduccion. El sindrome de encefalopatia posterior reversible (SEPR) es un sindrome clinico-radiologico de presentacion aguda o subaguda que se caracteriza por la presencia de cefalea, vomitos, crisis epilepticas, trastornos visuales y alteracion del nivel de conciencia asociado a lesiones localizadas fundamentalmente en la sustancia blanca de regiones posteriores cerebrales. Caso clinico. Mujer de 32 años que desarrollo un SEPR en el periodo posparto secundario a eclampsia tardia. La paciente presento 10 dias despues del parto un cuadro clinico consistente en cefalea, crisis epilepticas, ceguera y deterioro del nivel de conciencia. El estudio de imagen con resonancia magnetica confirmo la afectacion de la sustancia blanca de predominio posterior. Conclusiones. Aunque la eclampsia es una entidad tipica del embarazo y puerperio inmediato, es necesario recordar que tambien puede producirse de forma tardia tras el parto y que puede ser la causa de otros sindromes, como el SEPR. Aunque en estos casos el pronostico suele ser favorable, el tratamiento debe ser precoz, efectuando un rapido control de la tension arterial y las convulsiones con el fin de evitar un daño cerebral permanente. Es necesario considerar siempre este sindrome en mujeres con crisis epilepticas u otros sintomas neurologicos durante el posparto.

  11. Clinical spectrum and critical care management of Posterior Reversible Encephalopathy Syndrome (PRES).

    PubMed

    Striano, Pasquale; Striano, Salvatore; Tortora, Fabio; De Robertis, Edoardo; Palumbo, Daniela; Elefante, Andrea; Servillo, Giuseppe

    2005-11-01

    Posterior Reversible Encephalopathy (PRES) is characterized by acute-onset headache, altered mental status, cortical blindness and seizures, with parietal-occipital involvement. We report all cases of PRES diagnosed in our intensive care unit during the last 4 years, and evaluate their outcome in terms of the different medical treatments used. Even if usually reversible, PRES can sometimes result in death or irreversible neurological deficit, such as chronic epilepsy. From January 2001 to January 2005, we identified 8 female patients with PRES. All patients underwent basal and follow-up brain MRI. Patients referred to Epilepsy Center (about 3000 patients) were reviewed in order to identify subjects with a clinical history of PRES. These latter were clinically re-evaluated and underwent video-EEG, MRI study and neuropsychological testing. Of the 8 patients, 5 had hypertensive encephalopathy during pregnancy; 2 had eclampsia during the postpartum period; 1 patient with chronic renal failure developed symptoms after immunosuppressive treatment. In all patients but 1, neurological and radiological abnormalities resolved after appropriate treatment. In addition, we found 2 patients with temporal lobe epilepsy subsequent to a previous PRES. MRI revealed cortical-subcortical malacia in the parietal-occipital regions. The widespread use of MRI technology has made PRES familiar to many clinicians. Although PRES is reversible when treatment is instituted, delayed diagnosis and therapy can result in chronic neurological sequelae. The relationship between hypertensive encephalopathy and chronic epilepsy needs to be confirmed by longitudinal studies. Normalization of blood pressure and treatment of seizures deserves particular attention.

  12. Posterior Reversible Encephalopathy Syndrome (PRES) in 5-year-old girl with nephrotic syndrome.

    PubMed

    Kabicek, Pavel; Sulek, Stepan; Seidl, Zdenek; Vaneckova, Manuela; Kabickova, Edita; Vobruba, Vaclav; Wenchich, Laszlo; Zeman, Jiri

    2010-01-01

    Posterior Reversible Encephalopathy Syndrome (PRES) is a rare complication of nephrotic syndrome in children. This clinical condition is caused by localized brain angioedema mostly in parieto-occipital region and results in dramatic and acute features as sudden loss of consciousness, epileptic paroxysms, strong headache or visual disturbances. Uncontrolled hypertension often participates in PRES development. We present the case of a 5-year-old girl treated for relapse of nephrotic syndrome. At the time of edema regression and weight reduction, a sudden loss of consciousness and worsening of hypertension occurred. Brain MRI demonstrated extended multifocal changes strongly suspicious of encephalitis. After exclusion of herpetic encephalitis, the clinical picture was classified as PRES. Successful antihypertensive treatment led to general improvement of the girl's health within 48 hours and resolution of MRI brain hyperintensities occurred within the next three months. The aim of our case report is to us remind of possible development of PRES at the time of edema regression in nephrotic syndrome.

  13. Microcirculation Approach in HELLP Syndrome Complicated by Posterior Reversible Encephalopathy Syndrome and Massive Hepatic Infarction

    PubMed Central

    Sarmento, Stephanno Gomes Pereira; Santana, Eduardo Feliz Martins; Campanharo, Felipe Favorette; Machado, Flavia Ribeiro; Moron, Antonio Fernandes

    2014-01-01

    HELLP syndrome is a complication of severe forms of preeclampsia and occurs mainly in the third trimester of pregnancy. In extreme cases, it may evolve unfavorably and substantially increase maternal mortality. We present the case of an 18-year-old pregnant woman who was admitted to our emergency service in her 31st week, presenting with headache, visual disturbances, and epigastralgia, with progression to a severe condition of HELLP syndrome followed by posterior reversible encephalopathy syndrome (PRES) and hepatic infarction. We highlight the approach taken towards this patient and the case management, in which, in addition to the imaging examinations routinely available, we also used the sidestream dark field (SDF) technique to evaluate the systemic microcirculation. PMID:25485160

  14. A Case of ALL Developing Posterior Reversible Encephalopathy Secondary to Hyponatremia.

    PubMed

    Eroglu, Nilgun; Bahadir, Aysenur; Erduran, Erol

    2017-03-23

    Posterior reversible encephalopathy syndrome (PRES), may be due to different causes. It may develop secondary to hypertension, renal decompensation, electrolyte imbalance, and chemotherapeutic drugs. We describe a case of acute lymphoblastic leukemia in which PRES developed secondary to hyponatremia despite being normotensive during receipt of chemotherapy. Magnetic resonance imaging findings were suggestive of PRES. Partial diffusion restriction was observed in lesions in the bilateral occipitoparietal regions and the cerebellum. The patient was treated with appropriate medications with the resolution of his stroke-like symptoms. No neurological deficit was observed and clinical condition improved. The patient continued with chemotherapy. Early diagnosis and treatment of this syndrome is important in terms of preventing neurological sequelae. Cases of secondary PRES developing for several etiological reasons have been reported in induction therapy, but no pediatric cases of PRES developing secondary to hyponatremia despite being normotensive while receiving chemotherapy in acute lymphoblastic leukemia have previously been reported.

  15. 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

  16. Gemcitabine and Cisplatin induced posterior reversible encephalopathy syndrome: A case report with review of literature

    PubMed Central

    Kabre, Rohit Santosh; Kamble, Krishna Marotirao

    2016-01-01

    Posterior reversible encephalopathy syndrome (PRES) is a recently described, scarcely documented clinical entity. PRES is caused by various factors, the most common being hypertension, followed by nonhypertensive causes such as renal diseases and immunosuppressive therapy. Recently, some cases have been reported about the association of increased use of cytotoxic and immunosuppressive agents in cancer patients, and relevant reports have increased with advances in radiological examinations. Here, we report a case of gallbladder cancer with liver metastasis undergoing gemcitabine- and cisplatin-based chemotherapy who presented with complaints of seizures, headache, and bilateral lower limb weakness. Thorough clinical examination, biochemical analysis, and radiological evaluation led to diagnosis of PRES. It is important to recognize this syndrome which will facilitate early diagnosis and prompt symptomatic management. Removal of causative agent is an important aspect of management. Studies are needed to identify factors of adverse prognostic significance and to develop neuroprotective strategies. PMID:27843969

  17. Rare Case of Posterior Reversible Leukoencephalopathy Syndrome Secondary to Acute Chest Syndrome

    PubMed Central

    Klein, Daniel; El-Sherif, Yasir

    2016-01-01

    We present a case of 29/m with a history of sickle cell disease who presented to the emergency department with sudden onset of chest, trunk, extremity, and back pain, consistent in quality and severity with the patient's usual pain crises. Soon after admission to the medical unit for acute chest syndrome (ACS), the patient developed sudden onset of hypertension associated with left sided hemiplegia, lethargy, dysarthria, aphasia, and left sided facial droop. Neuroimaging revealed that on MRI Brain there was multifocal extensive signal abnormality and a small focal areas of hemorrhage compatible with posterior reversible leukoencephalopathy syndrome (PRES). Patient was treated with levetiracetam and phenytoin and improved soon afterwards, with resolution seen on follow-up MRI two months later. PMID:27957377

  18. Perioperative posterior reversible encephalopathy syndrome in 2 pediatric neurosurgery patients with brainstem ependymoma.

    PubMed

    Gephart, Melanie G Hayden; Taft, Bonnie P; Giese, Anne-Katrin; Guzman, Raphael; Edwards, Michael S B

    2011-03-01

    Posterior reversible encephalopathy syndrome (PRES) has been described in pediatric neurooncology patients, although it has not been documented perioperatively in pediatric neurosurgery patients not actively receiving chemotherapy. Recently at the authors' facility, 2 cases of PRES were diagnosed perioperatively in children with brainstem ependymoma. Both patients had presented with hypertension, altered mental status, and seizures and demonstrated MR imaging features consistent with PRES. The patients were treated with antiseizure and antihypertension medications, leading to improvement in both clinical symptoms and neuroimaging findings. These cases are the first to document PRES in perioperative pediatric neurosurgery patients not actively receiving chemotherapy. Both patients had ependymoma involving the brainstem, which may have led to intra- and perioperative hemodynamic instability (including hypertension) and predisposed them to this syndrome. An awareness of PRES in similar scenarios will aid in the prevention, diagnosis, and treatment of pediatric neurosurgery patients with this syndrome.

  19. Status Epilepticus and Blindness in a Patient with Carfilzomib-Associated Posterior Reversible Encephalopathy Syndrome

    PubMed Central

    Ebrahem, Rawaa; Cooper, Scott; Manlove, Emily; Lee, Ricky

    2017-01-01

    Posterior reversible encephalopathy syndrome (PRES) is a neurological condition characterized by headaches, visual disturbances, and seizures. A magnetic resonance imaging (MRI) scan of an affected brain typically shows symmetrical white matter edema in the posterior cerebral hemispheres. The onset of PRES can constitute a medical emergency, especially when accompanied by status epilepticus. If promptly recognized and treated, the clinical syndrome and associated radiological findings are usually resolved in a matter of weeks or months. Carfilzomib is a proteasome inhibitor that is newly approved for relapsing myeloma in a patient who has received one or more lines of therapy. In this paper, we report on a 52-year-old female on carfilzomib for multiple myeloma who developed PRES following her second dose of treatment. She was admitted for chronic obstructive pulmonary disease (COPD) exacerbation, and while she was in the hospital, she developed a severe headache, blindness, and status epilepticus. A brain MRI showed signs consistent with PRES. After carfilzomib was discontinued, her symptoms resolved within three days. Unfortunately, the patient passed away shortly after being discharged, so there was no opportunity to perform a repeat MRI. PMID:28357173

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

    PubMed Central

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

    2016-01-01

    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

  1. 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.

  2. Posterior Reversible Encephalopathy Syndrome as Presenting Form of Very Early Systemic Sclerosis

    PubMed Central

    Pedraza, María Isabel; Barbado, Julia; Ruiz, Marina; Guerrero, Ángel Luis

    2015-01-01

    Introduction. Posterior Reversible Encephalopathy Syndrome (PRES) is an increasingly recognized clinical and radiological entity with a wide spectrum of symptoms. Its mechanism depends on failure of the blood-brain barrier due to high systemic blood pressure (BP) and loss of integrity of vascular endothelium related with different triggers. Methods. We aim to report a case of PRES induced by arterial hypertension and very early systemic sclerosis (SSc) not previously known. Results. A 64-year-old female was admitted due to 1-week pulsating headache more prominent on frontal scalp, accompanied by phonophobia, photophobia, and facial flushing. Neurological exam revealed brisk deep tendon reflex. Brain magnetic resonance imaging (MRI) showed subcortical lesions mainly located in posterior regions. BP was monitored and episodic arterial hypertension was detected. In laboratory tests positive anti-topoisomerase I antibodies were detected. BP was controlled with angiotensin-converting-enzyme inhibitors and headache improved. In a new MRI a month later improvement of white matter lesions was observed. Capillaroscopy showed “active pattern,” considered typical of SSc. Conclusion. In SSc anti-endothelial cell antibodies impair vascular endothelium and liberation of vasoconstrictors leads to BP increasing and disruption of blood-brain barrier autoregulation mechanisms. PRES can be the first manifestation of very early SSc and this entity should be considered even in absence of skin lesions or Raynaud phenomenon. PMID:25802777

  3. [A clinical analysis of reninoma-induced hypertensive crisis associated with reversible posterior encephalopathy syndrome].

    PubMed

    Wu, Hong-hua; Wang, Guang-ya; Ma, Xiao-wei; Guo, Xiao-hui

    2012-01-01

    Reninoma is a rare benign tumor of the renal juxtaglomerular cell apparatus that causes hypertension and hypokalemia via hypersecretion of renin, while it is extremely rare that reninoma induced hypertensive crisis with reversible posterior encephalopathy syndrome (RPES). To improve the clinical understanding for this disease, we conducted a case-analysis. To analyze the clinical and pathological data of a case of reninoma-induced hypertensive crisis with reversible posterior encephalopathy syndrome, who was admitted to Peking University First Hospital in November, 2007 and follow-up. This was a 16-year old female patient, onset with suddenly spasm with loss of consciousness, while blood pressure stepped up to 210/140 mm Hg (1 mm Hg = 0.133 kPa), and the head magnetic resonance imaging (MRI) revealed "multiple long-T(2) signal", and hypokalemia (2.8 - 3.2 mmol/L), urine protein positive, ultrasound cardiogram revealed left ventricular hypertrophy, laboratory study revealed hyperreninism (38.23 ng·ml(-1)×h(-1), normal range 0.07 - 1.15 ng·ml(-1)×h(-1)) and hyperaldosteronism (660.9 ng/L, normal range 60 - 174 ng/L), abdominal CT-Scan revealed a mass at right kidney, blood pressure achieved safety range and the head MRI was rechecked and revealed "the abnormal long-T(2) signal disappeared". The clinical diagnosis was reninoma induced hypertensive crisis with RPES. The tumor was resected and the pathologic diagnosis was reninoma. The patient remained normotensive in the postoperative period without any medication. Reninoma represents a rare but surgically curable cause of hypertension, thus the clinical suspicion of it is very important in young patients. If the diagnosis is confirmed, positive treatment must be done immediately to improve the prognosis. The most common cause of RPES is hypertension, and the diagnosis depends on the distinctive head MRI. There is always a good prognosis with the decline of blood pressure rapidly.

  4. Various Imaging Manifestations of Posterior Reversible Encephalopathy Syndrome (PRES) on Magnetic Resonance Imaging (MRI)

    PubMed Central

    Raman, Rajesh; Devaramane, Radhika; Jagadish, Geetha Mukunda; Chowdaiah, Sanjana

    2017-01-01

    Summary Background Posterior reversible encephalopathy syndrome (PRES), also called the acute hypertensive encephalopathy and reversible posterior leukoencephalopathy syndrome (RPLS), is a neurotoxic syndrome of cerebral vasoregulation classically characterized by bilaterally symmetrical parieto-occipital edema. However, the imaging findings are variable and may occur in other locations such as the frontal lobes, thalami, basal ganglia and brainstem. Most commonly, PRES presents with hyperintense signals on T2 and FLAIR sequences. Restricted diffusion and hemorrhage are rare. This study presents the typical and atypical manifestations of PRES on 3T MR images. Material/Methods It is a retrospective study analyzing a radiology report database and MR images of 92 patients with a clinical and radiological diagnosis of PRES. The brain MRI images of these patients were evaluated. The regions involved and the signal intensity of the affected areas on T1, T2, FLAIR and DW sequences were recorded. The location of the abnormal signal intensity as well as the presence or absence of atypical features such as diffusion restriction and hemorrhage were also recorded. Results The most commonly affected region was the parieto-occipital lobes (100%), however, other atypical regions involved were the frontal lobes (30.4%), temporal lobes (8.69%), basal ganglia (22%), cerebellum(17.39%), brainstem(9%) and thalamus(4%). Some of the cases showed restricted diffusion (43%) and hemorrhage (9%). Conclusions The involvement of the parieto-occipital, frontal and temporal lobes is common in PRES. Occasionally, there may be an involvement of the basal ganglia, cerebellum and brainstem, with or without hemorrhage and restricted diffusion. Radiologists should be aware of the typical and atypical imaging manifestations of PRES in order to make an accurate diagnosis. PMID:28243339

  5. [Posterior reversible encephalopathy syndrome: Report of a fatal case and analysis of predictive factors of a poor prognosis].

    PubMed

    Torres, Moisés Ulises; Delgado, Ligia Victoria; Giraldo, Natalia; Urueña, Piedad; Franco, Sergio; Hernández, Olga Helena

    2017-04-01

    Posterior reversible encephalopathy syndrome is an illness with multiple causes and distinctive clinicalradiological characteristics that should be known by intensivists and emergency room physicians for a timely diagnosis and treatment. A fatal case of posterior reversible encephalopathy syndrome is presented, and the risk factors related to the outcome are identified.A 60-year-old man without a relevant medical history arrived at the emergency room presenting with depressed consciousness, seizures, and high blood pressure. Tomographic images revealed a posterior cerebellar hematoma. Resonance images showed ischemic zones, vasogenic edema from the thalamus to the brain stem, middle cerebellar peduncles, deep white matter of the cerebral hemispheres, and zones of hemorrhagic transformation. Despite medical-surgical management, the patient died. The risk factors described as the cause of the fatal outcome were identified. This case demonstrates that posterior reversible encephalopathy syndrome can occur without triggering risk factors and highlights the need for early recognition to establish an appropriate intervention to avoid injury or a fatal outcome. Cases of posterior reversible encephalopathy syndrome provide opportunities to investigate the susceptibility for the development of this condition and to establish appropriate preventive measures.

  6. Posterior reversible encephalopathy syndrome (PRES) with immune system activation, VEGF up-regulation, and cerebral amyloid angiopathy.

    PubMed

    Kofler, Julia; Bartynski, Walter S; Reynolds, Thomas Q; Lieberman, Frank S; Murdoch, Geoffrey H; Hamilton, Ronald L

    2011-01-01

    The case of a 75-year-old man with a history of lymphoma, recent upper respiratory tract infection, and a protracted course of encephalopathy is presented. Radiologically, findings were consistent with posterior reversible encephalopathy syndrome. A brain biopsy revealed evidence of endothelial activation, T-cell trafficking, and vascular endothelial growth factor expression, suggesting that systemic immune system activation may be involved with triggering posterior reversible encephalopathy syndrome. In addition, underlying cerebral amyloid angiopathy may have contributed to the initial nonclassical edema distribution by compromising autoregulatory blood flow mechanisms.

  7. Recurrent posterior reversible encephalopathy syndrome in a pediatric patient with end-stage renal disease.

    PubMed

    Daniel, Nicholas J; Hernandez, Cynthia L; Walker, Richard A

    2014-02-01

    Posterior reversible encephalopathy syndrome (PRES) is a condition manifested by altered mental status, seizures, headaches, and visual loss. Specific abnormalities are seen by computed tomography or magnetic resonance imaging. Awareness of this syndrome is important for Emergency Physicians because visual loss can be reversible with prompt treatment of the underlying cause. We present a case of recurrent PRES in a 14-year-old female who presented to the Emergency Department (ED) for headache and photosensitivity. A patient with a history of end-stage renal disease of unknown etiology was brought in by her mother for headache and photosensitivity. The patient developed blurry vision, seized in the ED, and required intubation. She was discharged 2 weeks later with complete return of vision. The same patient presented to the ED many times during the next several months for hypertensive emergencies, with three subsequent episodes that involved either seizures, vision loss, or both. Each of the episodes resolved with aggressive control of blood pressure in the pediatric intensive care unit. PRES should be considered in all patients presenting to the ED with visual loss, seizures, or headache, and can be recurrent in some individuals. Prompt treatment can help prevent permanent vision loss. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Reversible posterior leukoencephalopathy syndrome in a patient with multiple system atrophy: a possible association with oral midodrine treatment.

    PubMed

    Kim, Joong-Seok; Lee, Kwang-Soo; Lim, Sung-Chul; Ahn, Jae-Young; Song, In-Uk; Kim, Yeong-In; Kim, Bum-Soo; Kim, Hee-Tae

    2007-05-15

    We describe a 51-year-old man with a 3-year history of multiple system atrophy, who developed a reversible posterior leukoencephalopathy syndrome (RPLS) after receiving prescription midodrine for therapeutic treatment of orthostatic hypotension. Typical reversible magnetic resonance imaging findings, following treatment with midodrine, suggested a possible relationship between midodrine treatment, supine hypertension, and RPLS, although a cause-and-effect relationship cannot be confirmed. (c) 2007 Movement Disorder Society.

  9. Posterior reversible encephalopathy syndrome and systemic vasculitis: report of six cases.

    PubMed

    Lioger, Bertrand; Diot, Elisabeth; Ebbo, Michael; Schleinitz, Nicolas; Aaron, Laurent; Michot, Jean-Marie; Lambotte, Olivier; Dhote, Robin; De Boysson, Hubert; Ponce, Elodie; Maillot, François

    2016-01-01

    Our objective was to describe the characteristics of posterior reversible encephalopathy syndrome (PRES) associated with systemic vasculitis. A standardised questionnaire was used for a nationwide retrospective multicentre study in 2013 to collect clinical, radiological and outcome data about PRES associated with systemic vasculitis. We included six patients (all women; mean age 22.6±19.8 years (20-62)): two with polyarteritis nodosa and one case of each granulomatosis with polyangiitis, cryoglobulinaemic vasculitis, hypocomplementemic urticarial vasculitis, and Takayasu arteritis. PRES was the first manifestation of systemic vasculitis in three patients. Arterial hypertension was suspected to be the cause of PRES in five patients. Several other plausible causes including drugs, renal failure, and pneumonia were found in three patients. Clinical findings included headache, seizure, blurred or loss of vision, confusion, and altered cognition. Radiological study showed oedema in the occipital region in all patients, with a reversible state in MRIs performed one week to one month after the onset of PRES. Therapies used included antihypertensive therapy (n=5), immunosuppressive therapy (corticosteroids (n=5), cyclophosphamide (n=4), azathioprine (n=1), methotrexate (n=1), plasma exchange (n=1)), antibiotics (n=1), anticonvulsant therapy (n=2)), and analgesics. No relapse of PRES was reported during the follow-up period (mean: 47.5 ±29.9 months, 13-98); one patient continued to complain of vision loss. Our study indicates that PRES is a rare condition associated with systemic vasculitis; which may be present at the onset vasculitis symptoms. Antihypertensive drugs should be prescribed if blood pressure is elevated. The impact of immunosuppressive therapy remains unclear.

  10. Clinical Features and Outcomes of Patients with Posterior Reversible Encephalopathy Syndrome

    PubMed Central

    Kalaiselvan, M. S.; Renuka, M. K.; Arunkumar, A. S.

    2017-01-01

    Aims: The aim of this study was to study the clinical features and outcomes of patients with posterior reversible encephalopathy syndrome (PRES) admitted to the Intensive Care Unit (ICU). Subjects and Methods: All adult patients admitted to our ICU with acute onset neurologic symptoms with focal vasogenic edema on magnetic resonance imaging (MRI) were included in the study. Data were collected on demography, coexisting illness, admission severity of illness, neurological symptoms, blood pressure, treatment initiated, and MRI findings. Outcome data collected included mortality, ICU average length of stay (ALOS), number of ventilator days, and neurological disability at discharge assessed by modified Rankin scale (MRS). Results: Fourteen patients were admitted with PRES. Thirteen patients were female, and their mean age was 31.5 ± 8.3 years. Etiology of PRES included eclampsia (64.2%), lupus nephritis (21.4%), CKD (7.1%), and hypertension (n = 1 [7.1%]). The most common presenting symptom was seizure (92.8%), followed by visual disturbance (42.8%), headache (42.8%), encephalopathy (14.2%), and status epilepticus (14.2%). The Glasgow coma scale on admission was 12.3 ± 2.9. High blood pressure was seen in 12 patients 85.7%; their mean systolic and diastolic pressures were 173 ± 10.2 and 110 ± 8.6 mmHg, respectively. MRI showed that parieto-occipital region was most commonly involved (92.8%), followed by frontal lobe (42.8%). ICU ALOS was 4.35 ± 2.4 days and mean ventilator days was 1.7 ± 2.0 days. One patient (1/14 [7.4%]) died of multiorgan failure and 13 patients were discharged with no residual neurological deficit (MRS, 0). Conclusions: PRES is a potentially reversible disorder with prompt recognition and control of blood pressure. PMID:28808366

  11. Clinical Features and Outcomes of Patients with Posterior Reversible Encephalopathy Syndrome.

    PubMed

    Kalaiselvan, M S; Renuka, M K; Arunkumar, A S

    2017-07-01

    The aim of this study was to study the clinical features and outcomes of patients with posterior reversible encephalopathy syndrome (PRES) admitted to the Intensive Care Unit (ICU). All adult patients admitted to our ICU with acute onset neurologic symptoms with focal vasogenic edema on magnetic resonance imaging (MRI) were included in the study. Data were collected on demography, coexisting illness, admission severity of illness, neurological symptoms, blood pressure, treatment initiated, and MRI findings. Outcome data collected included mortality, ICU average length of stay (ALOS), number of ventilator days, and neurological disability at discharge assessed by modified Rankin scale (MRS). Fourteen patients were admitted with PRES. Thirteen patients were female, and their mean age was 31.5 ± 8.3 years. Etiology of PRES included eclampsia (64.2%), lupus nephritis (21.4%), CKD (7.1%), and hypertension (n = 1 [7.1%]). The most common presenting symptom was seizure (92.8%), followed by visual disturbance (42.8%), headache (42.8%), encephalopathy (14.2%), and status epilepticus (14.2%). The Glasgow coma scale on admission was 12.3 ± 2.9. High blood pressure was seen in 12 patients 85.7%; their mean systolic and diastolic pressures were 173 ± 10.2 and 110 ± 8.6 mmHg, respectively. MRI showed that parieto-occipital region was most commonly involved (92.8%), followed by frontal lobe (42.8%). ICU ALOS was 4.35 ± 2.4 days and mean ventilator days was 1.7 ± 2.0 days. One patient (1/14 [7.4%]) died of multiorgan failure and 13 patients were discharged with no residual neurological deficit (MRS, 0). PRES is a potentially reversible disorder with prompt recognition and control of blood pressure.

  12. Posterior reversible encephalopathy as the first manifestation of Bickerstaff's brainstem encephalitis.

    PubMed

    Chen, Pei-Ru; Chen, Shih-Pin

    2016-11-08

    Posterior reversible encephalopathy syndrome (PRES) has been associated with Guillain-Barre syndrome in rare cases. Here we report a patient in whom PRES was the presenting manifestation of Bickerstaff's brainstem encephalitis. A 75-year-old woman presented with acute onset of hypertension, headache, blurred vision, and left eyelid drooping. Magnetic resonance imaging of the brain showed characteristic PRES lesions involving the parietal and occipital lobes bilaterally. On the 6th day after symptom onset, the patient developed complete ptosis and external ophthalmoplegia of both eyes, progressive ataxia, and bilateral lower limb weakness. Cerebrospinal fluid analyses revealed albuminocytological dissociation (protein: 66.6 mg/dL, WBC: 0/μl), and nerve conduction studies showed demyelinating sensorimotor polyneuropathy. The patient developed somnolence and a left extensor plantar response on the 8th day. A diagnosis of Bickerstaff's brainstem encephalitis was made. Treatment with plasmapheresis led to a rapid improvement of clinical symptoms. To date, only five similar cases have been reported, but this is the only case in which PRES developed prior to treatment. PRES can be a comorbid condition with Bickerstaff's brainstem encephalitis, either preceding or following treatment; caution should be used in patients with either syndrome who exhibit atypical presentations.

  13. Posterior reversible encephalopathy syndrome in setting of postobstructive diuresis and persistent hypocalcemia.

    PubMed

    Gera, Dinesh N; Patil, Sachin B; Parikh, Mitul; Modi, Pranjal R; Kute, Vivek B; Trivedi, Hargovind L

    2012-01-01

    Posterior reversible encephalopathy syndrome (PRES) is a clinicoradiographic entity of heterogenous etiologies, which are grouped together because of similar findings on neuroimaging studies, associated with similar symptom complex of headache, vision loss, altered mentation, and seizures. In this report, we describe a case of PRES in setting of postobstructive diuresis in a 5-year-old male child, whose solitary functioning kidney was obstructed by a 1.6-cm radio-opaque stone, who after percutaneous nephrostomy (PCN) diversion developed persistent hypocalcemia which persisted despite maximum replacement by iv calcium gluconate drip, and the child developed repeated generalized tonic clonic convulsions and became unconscious for 4 days. Computerized tomography (CT) scan of the brain showed typical hypodensities in bilateral occipitoparietal regions suggesting PRES. Ultimately, over a period of 4 days, his hypocalcemia could be corrected and the child was neurologically normal on the 5th day. CT scan of the brain after a month was free of any hypodensities.

  14. Posterior reversible encephalopathy syndrome in a uremic patient with autosomal recessive polycystic kidney disease.

    PubMed

    Yoshida, Tadashi; Hiratsuka, Ken; Yamashita, Maho; Matsui, Ayumi; Hayashi, Matsuhiko

    2015-11-01

    Posterior reversible encephalopathy syndrome (PRES) is characterized by headache, seizures, altered mental status, and visual disturbance. It is diagnosed by the presence of both clinical symptoms and radiographic findings on the parietal-occipital lobes. We here report a 61-year-old woman with non-compensative liver cirrhosis and chronic kidney disease, presenting with uremia-induced PRES. She expressed loss of consciousness and subsequent visual disturbance, during the progression of uremia. She was treated with hemodiafiltration therapy, and the symptoms of PRES fully improved. The case is of particular interest, in that the appearance of abnormal findings on magnetic resonance imaging was delayed more than 2 weeks, as compared to that of clinical symptoms. The etiology of chronic kidney disease in the patient was considered to be autosomal recessive polycystic kidney disease, and we performed DNA sequencing analysis on the polycystic kidney and hepatic disease 1 gene. Two homozygous missense mutations were found in the patient and may combinatorially affect the disease. This case raises a possibility that the incidence of PRES is much higher if the radiological examination is performed more frequently.

  15. Posterior Reversible Encephelopathy Syndrome Presenting as Quadriparesis in Pregnancy Induced Hypertension

    PubMed Central

    Pranita; Kumar, Ajit; Shahi, Seema

    2015-01-01

    Pregnancy Induced Hypertension (PIH) is a condition characterised by raised blood pressure in pregnancy. It affects approximately one out of every 14 pregnant women. Although PIH more commonly occurs during first pregnancy, it can also occur in subsequent pregnancies. It can present with variable complications related to vasospasm. But focal neurologic deficits are extremely rare in patients with PIH. We report a case of quadriparesis due to posterior reversible encephalopathy syndrome (PRES). A 36 year old full term pregnant female was admitted for emergency lower segment caesarean section (LSCS) as a result of uncontrolled PIH with early clinical signs of left ventricular failure. She was recovering well from pulmonary oedema after being provided with mechanical ventilation. However on 4th day she developed sudden onset quadriparesis without any alteration in sensorium, bladder & bowel disturbance or any sensory deficit. Diffusion weighted neuroimaging (DWI) was carried out which revealed finding suggestive of PRES. The patient was treated with antihypertensive which followed improvement in neurological deficit. Although rare, PRES should be considered as a potential cause of acute onset focal neurological deficit in pregnant females with PIH. With this case report we have tried to create awareness and vigilance about rare but potentially serious yet salvageable condition like PRES. PMID:26023585

  16. Muscle force and excursion requirements and moment arm analysis of a posterior-superior offset reverse total shoulder prosthesis.

    PubMed

    Onstot, Brian R; Jacofsky, Marc C; Hansen, Matthew L

    2013-01-01

    Current reverse total shoulder arthroplasty prosthesis designs do not permit offset of the humerus in the sagittal plane. Posteriorly shifting the humerus has the theoretical benefit of lengthening the infraspinatus and teres minor muscles and their external rotation moment arms, thereby improving the tension and efficiency of each external rotator and subsequently requiring each muscle to produce less force to rotate the arm. A cadaveric shoulder controller was used to quantify the impact of a novel posterior-superior offset reverse shoulder prosthesis on muscle length, moment arms, and muscle forces relative to a non-offset reverse shoulder design during two different motions: scapular plane abduction and internal/external rotation. The results of this study demonstrate that both the non-offset and offset reverse shoulder designs had similar force and excursion demands of the infraspinatus and teres minor muscles during both scapular abduction and internal and external rotation. Additionally, the offset reverse shoulder design was associated with significantly less over-tensioning of the middle and posterior deltoid and significantly more anatomic tensioning of the teres minor than the non-offset design. However, the offset reverse shoulder was observed to have more impingement than the non-offset design. These findings support the feasibility of this design: by restoring a more anatomic resting length to the deltoid and teres minor, the posterior-superior offset rTSA design may provide better teres minor function and rotational strength and may decrease the incidence of acromial stress fractures relative to the non-offset design. Clinical follow-up is required to confirm these findings.

  17. Slow or rapid palatal expansion for early treatment of unilateral posterior crossbite? Evaluation of the reverse chewing cycles correction.

    PubMed

    Piancino, Maria G; Talpone, Francesca; Vallelonga, Teresa; Frongia, Gianluigi; Debernardi, Cesare L; Bracco, Pietro

    2010-01-01

    It is well established that patients with a unilateral posterior crossbite, when chewing on the affected side, show an increased frequency of reverse chewing cycles. It was hypothesized that the correction of reverse cycles may be due to the characteristics of the therapy. The aim was to investigate the prevalence of reverse chewing patterns in children with unilateral posterior crossbite before and after treatment with Function Generating Bite (FGB). Twenty children, (9 boys, 11 girls; age, mean ± SD, 7.5 ± 1.1), 10 with a right and 10 with a left posterior unilateral crossbite were selected. Mandibular movements during chewing soft and hard boluses were measured with a kinesiograph (K7 -I, Myotronics Inc. Tukwila, Washington, USA). The results showed a significant difference when comparing the percentage of reverse chewing patterns, before and after therapy with FGB, during chewing on the crossbite side both with soft and hard bolus (p<0.0001). No significant differences were observed during chewing on the non-crossbite side. The results of this study confirmed that FGB corrects both the dental and functional asymmetries. Knowing that the rapid palatal expansion does not correct the masticatory function, it is of clinical relevance, for the orthodontists, the knowledge and the understanding of the functional outcomes with different therapies. The type of treatment and the biomechanics of the appliance used are of great importance for the correction of the reverse chewing cycles and for rebalancing the functional asymmetry of children with unilateral posterior crossbite. Copyright © 2010 Società Italiana di Ortodonzia SIDO. Published by Elsevier Srl. All rights reserved.

  18. Unilateral posterior reversible encephalopathy syndrome with hypertensive therapy of contralateral vasospasm: case report.

    PubMed

    Dhar, Rajat; Dacey, Ralph; Human, Theresa; Zipfel, Gregory

    2011-11-01

    Hemodynamic treatment of subarachnoid hemorrhage-induced vasospasm is associated with a number of systemic and cerebral risks. However, hypertensive encephalopathy has rarely been reported in the setting of induced hypertension. Recognition of this complication is nonetheless critical because failure to lower blood pressure may lead to worsening of deficits and even permanent injury. This report details a case of unilateral hypertensive encephalopathy (also referred to as posterior reversible encephalopathy syndrome [PRES]) in a subarachnoid hemorrhage patient who was being treated with induced hypertension for symptomatic vasospasm affecting the contralateral hemisphere. This patient developed right hemispheric deficits associated with angiographic vasospasm of the right middle cerebral artery, which responded to induced hypertension. However, within 24 hours of raising blood pressure, the patient deteriorated with new left hemispheric deficits that paradoxically worsened when blood pressure was raised further in response. Computed tomography imaging was suspicious for evolving infarction in the left hemisphere, but on reevaluation, concern for PRES was raised. Magnetic resonance imaging confirmed left hemispheric PRES, and a dramatic neurological improvement occurred almost immediately after lowering blood pressure. Repeat CT showed resolution of the left hemispheric edema. This is the first reported case of unilateral PRES in the setting of subarachnoid hemorrhage. It likely occurred because right-sided vasospasm attenuated ipsilateral distal perfusion pressures, leaving the left hemisphere vulnerable to the consequences of induced hypertension. Hypertensive encephalopathy should be considered in patients with unilateral or asymmetric vasospasm when neurological worsening occurs in the contralateral hemisphere during induced hypertension and/or the patient paradoxically worsens despite raising blood pressure.

  19. Long-term risk of seizures and epilepsy in patients with posterior reversible encephalopathy syndrome.

    PubMed

    Datar, Sudhir; Singh, Tarun; Rabinstein, Alejandro A; Fugate, Jennifer E; Hocker, Sara

    2015-04-01

    Seizures are common in patients with posterior reversible encephalopathy syndrome (PRES), which is reported in up to 70% of cases, and antiepileptic drugs (AEDs) are commonly prescribed. There is a paucity of data regarding the risk of subsequent seizures following resolution of PRES, and therefore the optimal duration of treatment with AEDs is currently unknown. The objective of this study was to identify the frequency of recurrent seizures and epilepsy following recovery from PRES. We performed a retrospective review of consecutive adults diagnosed with PRES between 2000 and 2010. One hundred twenty-seven patients, median age 53 years (interquartile range [IQR] 37-64), were included in the analysis. The most common causes of PRES were hypertension (72%) and immunosuppression (20%). Renal failure was present in 47%. Eighty-four patients (66%) had seizures at presentation (39 focal, 45 generalized), and 13 (15%) of them presented with status epilepticus. Median duration of follow-up was 3.2 years (IQR 4 months to 6.9 years). Patients with seizures were treated with AEDs for a median of 3 months (IQR 2-7). Fifteen patients (12%) had provoked seizures during the follow-up period; in eight (53%) patients seizures were caused by recurrent PRES. Only three patients had subsequent unprovoked seizures, one of whom was considered to have developed epilepsy. We conclude that unprovoked seizures and epilepsy are uncommon in patients who have recovered from PRES. Discontinuation of AEDs following resolution of PRES should be considered, provided there is adequate control of risk factors, and absence of factors that could substantially lower the seizure threshold. Wiley Periodicals, Inc. © 2015 International League Against Epilepsy.

  20. [Patient with posterior reversible encephalopathy syndrome with prolonged disturbance of consciousness and convulsion after cerebral aneurysm surgery].

    PubMed

    Ueda, Kayo; Hoshi, Takuo; Yorozu, Shinko; Okazaki, Junko; Motomura, Yuji; Masumoto, Tomohiko; Tsubokawa, Tsunehisa; Tanaka, Makoto

    2011-02-01

    A 73-year-old patient developed convulsion and prolonged disturbance of consciousness after clipping surgery for unruptured cerebral aneurysm. The patient's consciousness improved four days after surgery, and radiological findings suggested posterior reversible encephalopathy syndrome (PRES). The cause of PRES is thought to be dysfunction of blood brain barrier by a sudden increase in blood pressure. In case of unexplained convulsion and decreased level of consciousness, PRES should be considered with radiographic examinations including CT and MRI.

  1. Postpartum posterior reversible encephalopathy syndrome (PRES) in a twin pregnancy complicated by preeclampsia-eclampsia: case report.

    PubMed

    Papoutsis, D; El-Attabi, N; Sizer, A

    2014-01-01

    This is the second case in literature of posterior reversible encephalopathy syndrome (PRES) in a twin pregnancy complicated by preeclampsia-eclampsia. A 27-year-old primigravida with dichorionic diamniotic twin pregnancy was admitted at 36 weeks of gestation for induction of labour due to preeclampsia. On the second day postpartum, the patient developed severe hypertension, visual symptoms, confusion, headache, and eclamptic fits. Head computed tomography (CT) showed hypodense basal ganglia lesions. The patient was treated in the intensive treatment unit with hydralazine and labetalol infusions and anticonvulsants. Five days later, there was complete clinical improvement and follow-up magnetic resonance imaging (MRI) was normal. The patient was discharged 11 days post-delivery. Diagnosis of PRES is based on the presence of clinical features of acute neurologic compromise, abnormal neuroimaging findings, and complete reversibility of findings after prompt treatment. Early recognition and proper treatment result in complete reversibility of this condition.

  2. Posterior reversible encephalopathy syndrome in an untreated hypertensive patient after spinal surgery under general anesthesia -A case report-

    PubMed Central

    Yi, Ji Hwan; Ha, Sang Hee; Kim, Yong Kook

    2011-01-01

    Posterior reversible encephalopathy syndrome (PRES) is an unfamiliar term to anesthesiologists, and this is characterized by neurologic symptoms that include mental change, headache, seizure and visual disturbance and also abnormal neuroimaging finding. A 71-year-old female patient was operated on for posterior decompression and total laminectomy under general anesthesia for the spinal stenosis. After the operation, she developed generalized tonic-clonic seizure and a stuporous mentality in the recovery room. The magnetic resonance imaging (MRI) revealed swelling and increased signal intensity at the deep gray nuclei, cerebral cortex and cerebellum. After one week, she returned to an alert mentality and then she was diagnosed with PRES. She was discharged without any neurologic deficit on postoperative day 20. This report describes our experience with PRES after spinal surgery was performed under general anesthesia on a suspected untreated hypertensive patient. PMID:21716568

  3. Posterior Reversible Encephalopathy Syndrome and Fatal Cryptococcal Meningitis After Immunosuppression in a Patient With Elderly Onset Inflammatory Bowel Disease

    PubMed Central

    Vasant, Dipesh H.; Limdi, Jimmy K.; Borg-Bartolo, Simon P.; Bonington, Alec

    2016-01-01

    Advanced age and associated comorbidities are-recognized predictors of life-threatening adverse outcomes, such as opportunistic infection following immunosuppressive therapy. We describe the case of an elderly patient with stricturing colonic Crohn’s disease and significant clinical comorbidities, initially controlled with corticosteroid induction followed by infliximab, whose course was complicated by fatal disseminated cryptococcal infection and posterior reversible encephalopathy syndrome. Our patient’s case highlights rare, but serious, complications of immunosuppression. In applying modern treatment paradigms to the elderly, the clinician must consider the potential for more pronounced adverse effects in this potentially vulnerable group, maximizing benefit and minimizing harm. PMID:27807560

  4. The Number of Perforators Included in Reversed Flow Posterior Interosseous Artery Flap: Does It Affect the Incidence of Venous Congestion?

    PubMed Central

    Shaker, Ayman A.; Elbarbary, Amir S.; Sayed, Mohamed A.; Elghareeb, Mohamed A.

    2016-01-01

    Background: The purpose of this study is to decrease the incidence of venous congestion occurring in the reversed flow posterior interosseous artery flap used for coverage of hand defects. Methods: This may be achieved by studying the incidence of venous congestion in flaps including only 1 perforator and comparing the results with others including more than 1 perforator both in small and large sized flaps. Results: This study showed that inclusion of only 1 perforator in the flap decreased the incidence of venous congestion with complete flap loss in flaps to 5%. Also, it decreased the incidence of venous congestion with partial flap loss in flaps to 10%. Conclusions: The small sized reversed flow posterior interosseous artery flap should be less than 40 cm2 and should include only 1 perforator to decrease the incidence of venous congestion with partial and complete loss of the flap. The level of evidence for this study is the type II prospective comparative study. PMID:28293513

  5. Posterior Reversible Encephalopathy Syndrome (PRES): Restricted Diffusion does not Necessarily Mean Irreversibility

    PubMed Central

    Wagih, Alaa; Mohsen, Laila; Rayan, Moustafa M.; Hasan, Mo’men M.; Al-Sherif, Ashraf H.

    2015-01-01

    Summary Background Restricted diffusion is the second most common atypical presentation of PRES. This has a very important implication, as lesions with cytotoxic edema may progress to infarction. Several studies suggested the role of DWI in the prediction of development of infarctions in these cases. Other studies, however, suggested that PRES is reversible even with cytotoxic patterns. Our aim was to evaluate whether every restricted diffusion in PRES is reversible and what factors affect this reversibility. Material/Methods Thirty-six patients with acute neurological symptoms suggestive of PRES were included in our study. Inclusion criteria comprised imaging features of atypical PRES where DWI images and ADC maps show restricted diffusion. Patients were imaged with 0.2-T and 1.5-T machines. FLAIR images were evaluated for the severity of the disease and a FLAIR/DWI score was used. ADC values were selectively recorded from the areas of diffusion restriction. A follow-up MRI study was carried out in all patients after 2 weeks. Patients were classified according to reversibility into: Group 1 (reversible PRES; 32 patients) and Group 2 (irreversible changes; 4 patients). The study was approved by the University’s research ethics committee, which conforms to the declaration of Helsinki. Results The age and blood pressure did not vary significantly between both groups. The total number of regions involved and the FLAIR/DWI score did not vary significantly between both groups. Individual regions did not reveal any tendency for the development of irreversible lesions. Similarly, ADC values did not reveal any significant difference between both groups. Conclusions PRES is completely reversible in the majority of patients, even with restricted diffusion. None of the variables under study could predict the reversibility of PRES lesions. It seems that this process is individual-dependent. PMID:25960819

  6. Task-specific reversal of visual hemineglect following bilateral reversible deactivation of posterior parietal cortex: a comparison with deactivation of the superior colliculus.

    PubMed

    Lomber, S G; Payne, B R

    2001-01-01

    The purpose of the present study was to compare and contrast behavioral performance on three different tasks of spatial cognition during unilateral and bilateral reversible deactivation of posterior parietal cortex. Specifically, we examined posterior middle suprasylvian (pMS) sulcal cortex in adult cats during temporary and reversible cooling deactivation. In Task 1, the cats oriented to a high-contrast, black visual stimulus moved into the visual field periphery. In Task 2, the cats oriented to a static light-emitting diode (LED). Task 3 examined the cats' ability to determine whether a black-and-white checkered, landmark box was closer to the right or left side of the testing apparatus. Following training on all tasks, cryoloops were implanted bilaterally within the pMS sulcus. Unilateral deactivation of pMS sulcal cortex resulted in virtually no responses to either moved or static stimuli and virtually no responses to landmarks presented in the contralateral hemifield, and a profound contralateral hemifield neglect was induced. Responses to stimuli and landmarks presented in the ipsilateral hemifield were unimpaired. Additive, bilateral cooling of the homotopic region in the contralateral hemisphere, but not an adjacent region, resulted in reversal of the initial hemineglect for the moved stimulus, yet induced a complete failure to orient to peripheral static LED stimuli. Bilateral cooling also reversed the contralateral neglect of the landmark, but then cats could not accurately determine position of the landmark anywhere in the visual field because performance was reduced to chance levels for all landmark loci in both hemifields. In this instance, as the contralateral neglect disappeared during bilateral cooling of pMS cortex, a new spatial discrimination deficit was revealed across the entire visual field. We conclude that pMS cortex contributes in multiple ways to the analyses of space, and that these contributions cannot be safely predicted from analyses

  7. 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.

  8. [Repair of skin and soft tissue defects on the wrist with reverse bi-pedicle posterior interosseous artery perforator flap].

    PubMed

    Li, Xiuquan; Sun, Guangfeng; Wang, Dali; Wei, Zairong; Qi, Jianping; Nie, Kaiyu; Jin, Wenhu; Deng, Chengliang; Li, Hai

    2014-10-01

    To explore the curative effect of reverse bi-pedicle posterior interosseous artery perforator flap in repairing skin and soft tissue defects on the wrist. Seven patients with soft tissue defects on the wrist, including simple skin and soft tissue defects in 4 cases and skin and soft tissue defects combined with radial tendon injury in 3 cases, were hospitalized from December 2010 to March 2012. The area of skin defect on the volar side of the wrist ranged from 4.8 cm x 4.0 cm to 6.2 cm x 4.5 cm, while that on the dorsal side ranged from 3.5 cm x 3.2 cm to 6. 5 cm x 5.4 cm. These wounds were respectively caused by traffic injury (3 cases), reamer injury (2 cases), burn (1 case), and tumor resection (1 case). Reverse bi-pedicle posterior interosseous artery perforator flaps were used to repair these defects, with area of one pedicle ranging from 2.5 cm x 2.0 cm to 3.5 cm x 2.5 cm and the area of the other pedicle ranging from 2.5 cm x 2.5 cm to 4.0 cm x 3.0 cm. The donor sites were closed by suturing. All flaps survived completely. Patients were followed up for 6 to 36 months. The color, texture, and appearance of all flaps were satisfactory. At last follow-up, distances of two-point discrimination of flaps ranged from 9 to 13 mm. The dorsal extension and palmar flexion functions of wrist were satisfactory. The results of function evaluation of 7 wrists were excellent in 6 cases and good in 1 case according to the tentative standards for the evaluation of upper extremity function of Society of Hand Surgery of Chinese Medical Association. A linear scar was formed at the donor site. The reverse bi-pedicle posterior interosseous artery perforator flap, with advantages of flexible design, easy to achieve, less injury to donor site, and reliable blood supply, etc., is another choice for repairing skin and soft tissue defects over the wrist.

  9. Posterior leukoencephalopathy syndrome as a cause of reversible blindness during pregnancy.

    PubMed

    Onderoglu, Lutfu S; Dursun, Polat; Gultekin, Murat; Celik, Nilufer Y

    2007-08-01

    Cortical blindness is a rare and dramatic complication of pre-eclampsia. The precise nature of the pathogenesis of this condition has not previously been understood. Three preeclamptic patients with unremarkable previous medical history presented with acute blindness between the 28th and 33rd weeks of pregnancy. They were all diagnosed as posterior leukoencephalopathy syndrome (PLES). In all these patients, MRI study revealed the typical feature of gray-white matter edema localized to the temporo-parieto-occipital areas. Vision and MRI findings were restored in all patients after delivery. Although PLES has been described as a puerperal clinicoradiologic entity, it may be seen in preeclamptic-eclamptic patients during the pregnancy. Therefore neuro-imaging studies should be carried out in pregnant patients with visual disturbances in order to exclude PLES. Prompt diagnosis, immediate control of blood pressure, and elimination of possible causes resolves clinical and imaging findings.

  10. Reversible posterior leukoencephalopathy syndrome in a patient with severe uremic encephalopathy.

    PubMed

    Tatsumoto, N; Fujisaki, K; Nagae, H; Ono-Fujisaki, A; Kura-Nakamura, N; Taniguchi, M; Masutani, K; Tsuruya, K; Iida, M

    2010-08-01

    A 59-year-old male presented at our hospital with disturbance of consciousness. He had severe neurological disturbances associated with uremia caused by severe renal insufficiency. Cranial computed tomography (CT) was normal on admission. FLAIR-weighted MRI showed increased signal intensities bilaterally in the cortical and subcortical areas of the occipital lobe. Repeated hemodialysis resulted in improvement of the clinical symptoms and blood chemistry, and normalization of the MRI findings. Although the patient was discharged without neurological deficit, he had to be maintained on regular intermittent hemodialysis due to persistent renal failure. These reversible neuroradiological abnormalities may have been caused by reversible brain edema, but other pathoetiological factors should be also considered, such as abnormalities of cerebral metabolism and effects of uremic toxins.

  11. [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.

  12. [Anesthetic Management of a Parturient with Eclampsia, Posterior Reversible Encephalopathy Syndrome and Pulmonary Edema due to Pregnancy-induced Hypertension].

    PubMed

    Aida, Junko; Okutani, Hiroai; Oda, Yutaka; Okutani, Ryu

    2015-08-01

    A 27-year-old woman with mental retardation was admitted to a nearby hospital for an abrupt onset of seizure. Physical examination revealed remarkable hypertension and pregnancy with estimated gestational age of 28th week. Severe pulmonary edema and hypoxia led to a diagnosis of pregnancy-induced hypertension (PIH) accompanied by eclampsia. She was orotracheally intubated because of refractory seizure and hypoxemia, and transferred to our hospital for further treatment. Besides severe hypoxia and hypercapnea, an enhanced lesion was detected in the left posterior cerebrum by brain MRI. No abnormal findings were detected in the fetus, with heart rate of 150 beats x min. She was diagnosed with posterior reversible encephalopathy syndrome (PRES) caused by PIH and emergency cesarean section under general anesthesia was scheduled. A male newborn was delivered with Apgar score of 1/4 (1/5 min), followed by starting continuous infusion of nicardipine for controlling hypertension. Chest X-P on completion of surgery revealed remarkably alleviated pulmonary edema. She received intensive treatment and continued positive pressure ventilation for four days after delivery. She recovered with no neurological deficits and her child was well without any complications.

  13. [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. Copyright © 2014 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

  14. TESTING BASAL GANGLIA MOTOR FUNCTIONS THROUGH REVERSIBLE INACTIVATIONS IN THE POSTERIOR INTERNAL GLOBUS PALLIDUS

    PubMed Central

    Desmurget, M.; Turner, R.S.

    2010-01-01

    To test current hypotheses on the contribution of the basal ganglia (BG) to motor control, we examined the effects of muscimol-induced inactivations in the skeletomotor region of the internal globus pallidus (sGPi) on visually-directed reaching. Injections were made in 2 monkeys trained to perform four out-and-back reaching movements in quick succession toward four randomly-selected target locations. Following sGPi inactivations: (1) Peak velocity and acceleration were decreased in nearly all sessions whereas movement duration lengthened inconsistently. (2) Reaction times were unaffected on average, although minor changes were observed in several individual sessions. (3) Outward reaches showed a substantial hypometria that correlated closely with bradykinesia, but directional accuracy was unaffected. (4) End-point accuracy was preserved for the slow visually-guided return movements. (5) No impairments were found in the rapid chaining of out-and-back movements, in the selection or initiation of four independent reaches in quick succession, or in the quick on-line correction of initially mis-directed reaches. (6) Inactivation-induced reductions in the magnitude of movement-related muscle activity (EMG) correlated with the severity of slowing and hypometria. There was no evidence for inactivation-induced alterations in the relative timing of EMG bursts, excessive co-contraction, or impaired suppression of antagonist EMG. Therefore, disconnecting the BG motor pathway consistently produced bradykinesia and hypometria, but seldom affected movement initiation time, feedback-mediated guidance, the capacity to produce iterative reaches, or the ability to abruptly reverse movement direction. These results are discussed with reference to the idea that the BG motor loop may regulate energetic expenditures during movement (i.e., movement “vigor”). PMID:18077663

  15. Delayed onset of posterior reversible encephalopathy syndrome in a case of scleroderma renal crisis with maintenance hemodialysis

    PubMed Central

    Chen, Ching-Yang; Hung, Shin-Yuan; Lee, Yi-Jer; Lin, Yi-Chan; Pai, Chu-Cheng

    2016-01-01

    Abstract Introduction: In some cases, scleroderma renal crisis (SRC) is not easily distinguishable from other thrombotic microangiopathies such as thrombotic thrombocytopenic purpura, especially when the presentation includes neurological or extra-renal manifestations. Here, we present a case of SRC who developed a rare neurotoxic complication, posterior reversible encephalopathy syndrome (PRES). A 36-year-old man with a history of diffuse cutaneous systemic sclerosis developed SRC and acute-on-chronic renal failure and ultimately required maintenance hemodialysis. Three weeks after starting hemodialysis, the patient presented with confusion and a new-onset seizure disorder. Laboratory examinations revealed thrombocytopenia, a low haptoglobin level, and schizocytes on a blood smear. SRC-related PRES was considered first after PRES was confirmed by brain magnetic resonance imaging. Antihypertensive therapy comprising captopril and amlodipine was administered, and the patient experienced a complete neurological recovery 3 days later without plasma exchange. In all previously reported cases of SRC-associated PRES, PRES developed before hemodialysis. Our report is, therefore, the first to describe a case of onset of SRC-related PRES 3 weeks after the initiation of maintenance hemodialysis. Conclusion: This case demonstrates that microangiopathy and extra-renal manifestations can develop even in SRC patients with end-stage renal disease and that these manifestations can be successfully managed with angiotensin-converting enzyme inhibitors (ACEIs) and aggressive blood pressure control. We recommend continuing ACEI therapy if elevated blood pressure persists after maintenance hemodialysis. PMID:28033278

  16. A case of posterior reversible encephalopathy syndrome associated with gilenya(®) (fingolimod) treatment for multiple sclerosis.

    PubMed

    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.

  17. Learning and recall of form discriminations during reversible cooling deactivation of ventral-posterior suprasylvian cortex in the cat.

    PubMed

    Lomber, S G; Payne, B R; Cornwell, P

    1996-02-20

    Extrastriate visual cortex of the ventral-posterior suprasylvian gyrus (vPS cortex) of freely behaving cats was reversibly deactivated with cooling to determine its role in performance on a battery of simple or masked two-dimensional pattern discriminations, and three-dimensional object discriminations. Deactivation of vPS cortex by cooling profoundly impaired the ability of the cats to recall the difference between all previously learned pattern and object discriminations. However, the cats' ability to learn or relearn pattern and object discriminations while vPS was deactivated depended upon the nature of the pattern or object and the cats' prior level of exposure to them. During cooling of vPS cortex, the cats could neither learn the novel object discriminations nor relearn a highly familiar masked or partially occluded pattern discrimination, although they could relearn both the highly familiar object and simple pattern discriminations. These cooling-induced deficits resemble those induced by cooling of the topologically equivalent inferotemporal cortex of monkeys and provides evidence that the equivalent regions contribute to visual processing in similar ways.

  18. 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

  19. Reverse pupillary block after implantation of a scleral-sutured posterior chamber intraocular lens: a retrospective, open study.

    PubMed

    Bang, Seung Pil; Joo, Choun-Ki; Jun, Jong Hwa

    2017-03-29

    To report the clinical features of patients with reverse pupillary block (RPB) after scleral-sutured posterior chamber intraocular lens (PC IOL) implantation and biometric changes after laser peripheral iridotomy (LPI). Eight patients attending our hospital's ophthalmology outpatient clinic, who developed RPB after implantation of a scleral-sutured PC IOL due to subluxation of the crystalline lens or IOL, were investigated in this retrospective, observational study. Preoperative evaluations showed angle pigmentation in all cases and iridodonesis in 2 cases. Two subjects had used an α1A-adrenoceptor antagonist for benign prostatic hyperplasia. Pars plana or anterior partial vitrectomy was performed in all cases. All eyes showed an extremely deep anterior chamber, a concave iris configuration, and contact between the IOL optic and the iris at the pupillary margin. Pupil capture was detected in 2 cases. The mean (± SD) anterior chamber angle (ACA) was 89.91 ± 10.06°, and the anterior chamber depth (ACD) was 4.42 ± 0.16 mm before LPI. After LPI, the iris immediately became flat with a decreased ACA (51.70 ± 2.59°; P = 0.018) and ACD (4.14 ± 0.15 mm; P = 0.012). After LPI, the intraocular pressure decreased from 19.75 ± 3.77 mmHg to 15.63 ± 4.30 mmHg (P = 0.011), and the spherical equivalent decreased from -0.643 ± 0.385 D to - 0.875 ± 0.505 D (P = 0.016). Concomitant vitrectomy, angle pigmentation, and iridodonesis may be risk factors for RPB after scleral-sutured PC IOL implantation. LPI is effective for relieving the RPB.

  20. Clinical and radiological features of posterior reversible encephalopathy syndrome in patients with pre-eclampsia and eclampsia.

    PubMed

    Dong, X Y; Bai, C B; Nao, J F

    2017-10-01

    To analyse and summarise clinical and radiological features among patients with posterior reversible encephalopathy syndrome (PRES), to assess related factors with eclampsia and pre-eclampsia, and to compare the different factors between cytotoxic and vasogenic oedema among PRES patients. The clinical and radiological findings of 237 pre-eclamptic or eclamptic patients with neurological symptoms were evaluated retrospectively. Multiple logistic regression analyses were performed to compare the differences among these parameters. Seventy-six patients (32.07%) were diagnosed with PRES. Multiple logistic regression indicated that seizure (odds ratio [OR], 2.760; 95% confidence interval [CI]: 1.087-7.011; p=0.033), visual disturbances (OR=2.062 95%CI, 1.033-4.115; p=0.004), multiple production history (OR=3.637; 95% CI: 1.068-8.228; p=0.002) were independent risk factors for PRES. PRES+ (OR=3.217; 95%CI, 1.346-7.686; p=0.009), Visual disturbances (OR=4.283; 95% CI: 1.843-9.953; p=0.001) had strong association with eclampsia. Visual disturbances (OR=7.200; 95% CI: 2.116-24.496; p=0.002) had strong correlation with eclampsia among PRES+ patients. Visual disturbances (OR=2.947; 95% CI: 1.135-7.648; p=0.026) were independently related to cytotoxic oedema. Nearly one-third of pre-eclampsia or eclampsia patients with neurological symptoms have PRES. Visual disturbances, seizure, multiple production history are independent risk factors for PRES. Visual disturbances have a strong association with eclampsia whether patients have PRES or not. Visual disturbances are independently related to cytotoxic oedema among PRES+ patients. Copyright © 2017 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  1. A Grave Outcome of Posterior Reversible Encephalopathy Syndrome in a Patient Receiving Avastin (Bevacizumab) for Metastatic High-Grade Serous Ovarian Cancer

    PubMed Central

    Elmalik, Hind H.; ElAzzazy, Shereen; Salem, Khaled S.; Bujassoum, Salha

    2015-01-01

    A 45-year-old female developed neurological symptoms and elevated diastolic blood pressure while on bevacizumab (Avastin) and gemcitabine for recurrent carboplatin-resistant high-grade serous ovarian cancer. A brain MRI diagnosed our patient with posterior reversible encephalopathy syndrome. We are discussing her presenting symptoms in this paper as well as the management and the outcome. We emphasize the importance of keeping this rare but very serious complication in all patients receiving bevacizumab. PMID:26351436

  2. 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…

  3. 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…

  4. Association of Posterior Reversible Encephalopathy Syndrome and Transient Apical Ballooning Syndrome (Takotsubo): First Case Report of a Man and Review of the Literature.

    PubMed

    Grimaldi, Stephan; Doche, Emilie; Rey, Caroline; Laksiri, Nadia; Boussen, Salah; Quilici, Jacques; Robinet, Emmanuelle; Devemy, Fabien; Pelletier, Jean

    2017-01-01

    An association of posterior reversible encephalopathy syndrome (PRES) and takotsubo is rare. We present the first case of a male patient. A 69-year-old man presented to the hospital in a persistent comatose state following a generalized tonic-clonic seizure with high blood pressure. The electrocardiogram revealed transient left bundle branch block. Troponin and BNP were elevated. Cardiac ultrasound showed large apical akinesia with altered left ventricular ejection fraction, and the left ventriculogram showed characteristic regional wall motion abnormalities involving the mid and apical segments. Brain MRI showed bilateral, cortical, and subcortical vasogenic edema predominant in the posterior right hemisphere. The lumbar puncture and cerebral angiography were normal. Paraclinical abnormalities were reversible within 2 weeks with a clinical recovery in 3 months, confirming the takotsubo and the PRES diagnoses. Several theories hypothesize the underlying pathophysiology of takotsubo or PRES. Circulating catecholamines are up to 3 times higher in patients with takotsubo causing impaired microcirculation and apical hypokinesia. An association of both takotsubo and asthma crisis and PRES and asthma crisis underlines the role of catecholamines in the occurrence of these disorders. Early recognition of this rare association, in which heart and neurological damage may require rapid intensive care support, is needed.

  5. Posterior reversible encephalopathy syndrome and stroke after intravenous immunoglobulin treatment in Miller-Fisher syndrome/Bickerstaff brain stem encephalitis overlap syndrome.

    PubMed

    Stetefeld, Henning R; Lehmann, Helmar C; Fink, Gereon R; Burghaus, Lothar

    2014-10-01

    The association of a posterior reversible encephalopathy syndrome (PRES) without arterial hypertension with autoimmune-mediated inflammatory neuropathies such as Guillain-Barré syndrome (GBS) is a rare and poorly understood phenomenon. To date, PRES has been described as initial manifestation, coincidental finding, or adverse event subsequent to immunomodulatory treatment with intravenous immunoglobulin (IVIG) in cases of axonal and demyelinating GBS as well as in Miller-Fisher syndrome (MFS). We here report a case of MFS/Bickerstaff brain stem encephalitis (BBE)-overlap syndrome and nonhypertensive PRES that occurred in close temporal association with IVIG treatment and caused stroke. Immunoadsorption ameliorated the disease course. Our case supports the notion that in severe cases, immunoadsorption should be considered as first-line therapy instead of IVIG for rapid removal of IgG and thus to hasten recovery and improve functional outcome. Copyright © 2014 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  6. Reversible posterior leukoencephalopathy syndrome and silent cerebral infarcts are associated with severe acute chest syndrome in children with sickle cell disease.

    PubMed

    Henderson, Jessica N; Noetzel, Michael J; McKinstry, Robert C; White, Desiree A; Armstrong, Melissa; DeBaun, Michael R

    2003-01-15

    Patients with severe acute chest syndrome (ACS) requiring endotracheal intubation and erythrocytopheresis are at increased risk for neurologic morbidity. This study examines patients with sickle cell disease who developed severe episodes of ACS, leading to endotracheal intubation, ventilatory support for respiratory failure, and erythrocytapheresis. Magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) studies, a neurologic examination by a pediatric neurologist, and cognitive testing were done in all patients. Five consecutive patients, aged 3 to 9 years, were identified with severe ACS. All patients developed neurologic complications resulting from ACS episodes, including seizures (n = 2), silent cerebral infarcts (n = 3), cerebral hemorrhage (n = 2), and reversible posterior leukoencephalopathy syndrome (n = 3). Children with severe ACS should have a magnetic resonance image of the brain, neurologic examination by a neurologist, and cognitive testing to detect the presence of neurologic morbidity.

  7. 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

  8. 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

  9. Reversals.

    ERIC Educational Resources Information Center

    National Center on Educational Media and Materials for the Handicapped, Columbus, OH.

    Selected from the National Instructional Materials Information System (NIMIS)--a computer based on-line interactive retrieval system on special education materials--the bibliography covers nine materials for remediating reversals in handicapped students at the early childhood and elementary levels. Entries are presented in order of NIMIS accession…

  10. 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

  11. 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

  12. Clinical and Radiological Spectrum of Posterior Reversible Encephalopathy Syndrome: Does Age Make a Difference? – A Retrospective Comparison between Adult and Pediatric Patients

    PubMed Central

    Siebert, Eberhard; Bohner, Georg; Endres, Matthias; Liman, Thomas G.

    2014-01-01

    Background Posterior reversible encephalopathy syndrome (PRES) is a serious and increasingly recognized disorder, but data from observational studies on clinicoradiological differences between etiologies and age groups are limited. In this study, we aimed to investigate the clinical and imaging characteristics of PRES in children compared to adults in a large cohort. Methods We retrospectively reviewed the radiological report data bases between January 1999 and August 2012 for patients with PRES (total of 110 patients). Patients fulfilling the criteria for PRES after detailed investigation of clinical charts and imaging studies were separated into children (<18years) and adults (≥18years). Various imaging features at onset of symptoms and on follow-up as well as clinical and paraclinical data were analyzed. Results A total of 19 pediatric and 91 adult patients with PRES were included into the study. In pediatric PRES patients, seizures were significantly more frequent as initial PRES-related symptom (p = 0.01). In addition, in children the superior frontal sulcus topographic lesion pattern occurred as frequent as the parieto-occipital one and was significantly more prevalent than in adults (p = 0.02). In contrast, in adults visual disturbances tended to occur more frequently than in children (p = 0.05). Also, severity of edema tended to be greater in adults than in children (p = 0.07). Conclusion In our PRES cohort, we found relevant clinicoradiological differences between pediatric and adult PRES patients. However, prospective studies are warranted to establish factors that are specifically associated with pediatric PRES. PMID:25514795

  13. Recurrent status epilepticus in posterior reversible encephalopathy syndrome as initial feature of pediatric lupus: A newly diagnosed case and literature review.

    PubMed

    Nasri, Amina; Bedoui, Ines; Mrissa, Ridha; Riahi, Anis; Derbali, Hager; Zaouali, Jamel; Messelmani, Meriem; Mansour, Malek

    2016-10-01

    Posterior reversible encephalopathy syndrome (PRES) is a recently described clinico-neuroradiological syndrome with several predisposing conditions. Systemic lupus erythematosus (SLE), beginning in 15-20% in childhood, is considered as a potential underlying etiology of PRES. In children, status epilepticus (SE) rarely complicates PRES, and exceptionally occurs in SLE. We report on an illustrative case of PRES complicating pediatric lupus revealed by recurrent SE, and we further review through a Pubmed search the previously reported cases of pediatric SLE, PRES and SE. We describe the case of a 12-year old girl who presented with recurrent status epilepticus associated to high blood pressure and renal involvement. Brain imaging showed classical aspects of PRES. Immunological tests including antinuclear, anti-DNA, and anticardiolipin antibodies were positive. The diagnosis of SLE was established. The Pubmed search identified a total number of 9 children with SE in SLE, and 26 with PRES, including our patient. We discussed the clinical and paraclinical features of PRES in SLE with epilepsy, their underlying pathophysiological aspects, and their management challenges. PRES should be considered in initial recurrent SE in children, justifying a battery of tests comprising immunological testing. Anticardiolipin antibodies seem to play a crucial role in epilepsy, PRES and renal involvement in pediatric SLE. Further studies are needed to clarify whether PRES should be considered one of the neuropsychiatric manifestations of SLE or a consequence of active disease in other organ systems or its treatment. Copyright © 2016 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

  14. Posterior scleritis.

    PubMed

    Benson, W E

    1988-01-01

    Posterior scleritis must be considered in the differential diagnosis of many ocular conditions, including angle closure glaucoma, choroidal folds, optic disk edema, circumscribed fundus mass, choroidal detachment, and exudative retinal detachment. Because it is rare, a high index of suspicion is necessary. Anterior scleritis, pain, or a history of collagen-vascular disease, when present, help to alert the clinician to the correct diagnosis. Posterior scleritis affects women more often than men, but annular ciliochoroidal effusion and choroidal folds are more common in men. Exudative macular detachment and a circumscribed fundus mass are more common in women. This paper reviews the world literature on posterior scleritis and describes findings in a series of 43 patients seen at Wills Eye Hospital. It stresses the clinical features and ancillary diagnostic tests that help to establish the diagnosis.

  15. Posterior Shoulder Instability.

    PubMed

    Brelin, Alaina; Dickens, Jonathan F

    2017-09-01

    Posterior shoulder instability is a relatively uncommon condition, occurring in ∼10% of those with shoulder instability. Because of the rarity of the condition and the lack of knowledge in treatment, it is often misdiagnosed or patients experience a delay in diagnosis. Posterior instability typically affects athletes participating in contact or overhead sports and is usually the result of repetitive microtrauma or blunt force with the shoulder in the provocative position of flexion, adduction, and internal rotation, leading to recurrent subluxation events. Acute traumatic posterior dislocations are rare injuries with an incidence rate of 1.1 per 100,000 person years. This rate is ∼20 times lower than that of anterior shoulder dislocations. Risk factors for recurrent instability are: (1) age below 40 at time of first instability; (2) dislocation during a seizure; (3) a large reverse Hill-Sachs lesion; and (4) glenoid retroversion. A firm understanding of the pathoanatomy, along with pertinent clinical and diagnostic modalities is required to accurately diagnosis and manage this condition.

  16. Spatial cognition and memory: a reversible lesion with lidocaine into the anteromedial/posterior parietal cortex (AM/PPC) affects differently working and long-term memory on two foraging tasks.

    PubMed

    Espina-Marchant, Pablo; Pinto-Hamuy, Teresa; Bustamante, Diego; Morales, Paola; Robles, Luis; Herrera-Marschitz, Mario

    2006-01-01

    Place memory is relevant for exploration and forage behaviour. When food supply is dispersed, a win-shift has advantage over a win-stay strategy. In the Olton Octagonal Maze, the rat follows a win-shift strategy using working memory. However, in the Olton 4x4 version, the rat follows a win-stay strategy, using both working and long-term memories. It has been suggested that the neocortex is required for the resolution of tasks demanding long-term, but not for that demanding working memory alone. The role of anteromedial/posterior parietal cortex (AM/PPC) was investigated here, using a reversible lesion induced by intracerebral lidocaine infusion. Long-Evans rats were implanted with guide cannulae into the AM/PPC and trained in an Olton 4x4 maze, counting working and long-term memory errors after a delay. Then, the animals were infused with lidocaine or saline during the delay phase and tested for three days. Another series of animals, treated as before, was tested in an Olton Octagonal Maze and subjected to the same injection schedule. In the Olton 4x4 Maze, lidocaine produced a significant increase in working and long-term memory errors, compared to saline and post-lidocaine conditions. In contrast, in the Olton Octagonal Maze, lidocaine did not induce any effect on working memory errors. Thus, AM/PPC is required when both working with previous information and long-term memories are needed, but not when only working memory is required, as it happens under ethological conditions. Whenever food supply is dispersed, a win-shift strategy is preferable.

  17. Posterior ankle impingement.

    PubMed

    Giannini, Sandro; Buda, Roberto; Mosca, Massimiliano; Parma, Alessandro; Di Caprio, Francesco

    2013-03-01

    Posterior ankle impingement is a common cause of chronic ankle pain and results from compression of bony or soft tissue structures during ankle plantar flexion. Bony impingement is most commonly related to an os trigonum or prominent trigonal process. Posteromedial soft tissue impingement generally arises from an inversion injury, with compression of the posterior tibiotalar ligament between the medial malleolus and talus. Posterolateral soft tissue impingement is caused by an accessory ligament, the posterior intermalleolar ligament, which spans the posterior ankle between the posterior tibiofibular and posterior talofibular ligaments. Finally, anomalous muscles have also been described as a cause of posterior impingement.

  18. Percutaneous Posterior Calcaneal Osteotomy.

    PubMed

    Lui, Tun Hing

    2015-01-01

    Different types of posterior calcaneal osteotomy are used for calcaneal realignment in the management of hindfoot deformity. We describe a percutaneous technique of posterior calcaneal osteotomy that can be either a Dwyer-type closing wedge osteotomy or displacement osteotomy.

  19. 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.

  20. Posterior Cruciate Ligament Injury

    MedlinePlus

    ... tear. Contact sports. Athletes in sports such as football and soccer can tear their posterior cruciate ligament ... vehicle accident and participating in sports such as football and soccer are the most common risk factors ...

  1. Recurrent posterior shoulder instability after rifle shooting.

    PubMed

    Cho, Jae-Ho; Chung, Nam-Su; Song, Hyung-Keun; Lee, Doo-Hyung

    2012-11-01

    Rifle shooting produces a sudden counterforce against the body thorough the anterior shoulder, which may produce a traumatic injury in soldiers. Posterior instability of the shoulder can occur in soldiers who practice rifle shooting. To the authors' knowledge, few reports have examined shooting-related injuries in soldiers. This article describes the case of a 27-year-old male soldier who presented with left shoulder pain and instability after rifle training. He developed symptoms, and presented radiographic findings consistent with a posterior Bankart lesion. Intraoperatively, while in the lateral decubitus position, a posterior portal was created 3 cm inferior and 2 cm lateral to the posterolateral corner of acromion for making a proper angle for inserting anchors. A reverse bony Bankart lesion and adjacent cartilage breakdown at the glenoid rim were noted. An arthroscopic capsulolabral repair was performed with 3-mm bioabsorbable anchors to the glenoid rim. No gross reverse Hill-Sachs lesion or hyaline cartilage lesion was noted. Postoperatively, the arm was supported in a sling with an abduction pillow for 5 weeks. Codman's exercises, scapular protraction exercises, and elbow and wrist exercises were started. Physical therapy focused on reestablishing glenohumeral range of motion and rotator cuff and periscapular muscle strength. Six months postoperatively, the patient had normal scapular kinesis and reported no shoulder pain or symptoms of instability associated with a reverse bony Bankart lesion. Copyright 2012, SLACK Incorporated.

  2. The tibialis posterior tendon.

    PubMed

    Lhoste-Trouilloud, A

    2012-02-01

    The tibialis posterior tendon is the largest and anteriormost tendon in the medial ankle. It produces plantar flexion and supination of the ankle and stabilizes the plantar vault. Sonographic assessment of this tendon is done with high-frequency, linear-array transducers; an optimal examination requires transverse retromalleolar, longitudinal retromalleolar, and distal longitudinal scans, as well as dynamic studies. Disorders of the posterior tibial tendon include chronic tendinopathy with progressive rupture, tenosynovitis, acute rupture, dislocation and instability, enthesopathies. The most common lesion is a progressive "chewing gum" lesion that develops in a setting of chronic tendinopathy; it is usually seen in overweight women over 50 years of age with valgus flat feet. Medial ankle pain must also be carefully investigated, and the presence of instability assessed with dynamic maneuvers (forced inversion, or dorsiflexion) of the foot. Sonography plays an important role in the investigation of disorders involving the posterior tibial tendon.

  3. Posterior vitreous detachment.

    PubMed

    Thimons, J J

    1992-01-01

    Posterior vitreous detachment is an expected consequence of aging, but it can also be the initiating cause of a retinal detachment. To understand the mechanism of posterior vitreous detachment and its sequelae, it is necessary to appreciate the anatomy of the vitreous, its development, and the pathogenesis of vitreous degeneration. This paper is a discussion of these considerations, the types of complications that may result from vitreous detachment, the proper examination of patients who present with the symptoms of vitreous detachment, and appropriate patient management.

  4. Posterior crossbites in children.

    PubMed

    Zhu, J F; Crevoisier, R; King, D L; Henry, R; Mills, C M

    1996-11-01

    Posterior crossbite, the most common malocclusion in young children, can be caused by a variety of skeletal, muscular, or dental factors. This condition produces insufficient maxillary arch width and is frequently associated with various oral sucking and postural habits. If left untreated, this problem can result in adverse skeletal growth changes. Various mechanical treatment modalities designed to expand the posterior maxillary arch width are available to correct this problem. The appropriate treatment method depends on the patient's age and level of cooperation as well as the determined etiology of the constriction.

  5. Posterior Fossa Tumors.

    PubMed

    Brandão, Lara A; Young Poussaint, Tina

    2017-02-01

    Pediatric brain tumors are the leading cause of death from solid tumors in childhood. The most common posterior fossa tumors in children are medulloblastoma, atypical teratoid/rhabdoid tumor, cerebellar pilocytic astrocytoma, ependymoma, and brainstem glioma. Location, and imaging findings on computed tomography (CT) and conventional MR (cMR) imaging may provide important clues to the most likely diagnosis. Moreover, information obtained from advanced MR imaging techniques increase diagnostic confidence and help distinguish between different histologic tumor types. Here we discuss the most common posterior fossa tumors in children, including typical imaging findings on CT, cMR imaging, and advanced MR imaging studies.

  6. 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.

  7. Posterior Knee Loose Bodies: Treated by Posterior Knee Arthroscopy

    PubMed Central

    Chai, Ho Lam; Lui, Tun Hing

    2017-01-01

    Introduction: The posterior portion of the knee joint, which includes the tibial attachment of the posterior cruciate ligament and the posterior horn of the menisci, has been called a “blind spot” because it is difficult to observe this area under arthroscopy through standard anterior portals. Posteromedial, posterolateral, and posterior transseptal portals have been developed for visualization and instrumentation of the posteromedial and posterolateral compartments of the knee joint. Case Report: A 57-year-old man presented of persistent left posterior knee pain for 1 year. Radiographs and magnetic resonance imaging showed posterior knee encapsulated loose bodies. The symptoms did not respond to physiotherapy and analgesics. The loose bodies were removed via posterior knee arthroscopy. The symptoms subsided afterward. Conclusion: Lateral portal of the knee allows establishment of the posterolateral portal under endoscopic visualization, and the loose bodies of the posterior compartment of the knee can be effectively removed via the posterior knee arthroscopy. PMID:28819604

  8. 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

  9. 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

  10. Subspecialization in the human posterior medial cortex.

    PubMed

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

    2015-02-01

    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-unconstrained but not task-constrained connectivity. We thus identified distinct regions in the PMC and characterized their neural networks and functional implications. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. Posterior Circulation Ischemic Stroke.

    PubMed

    Go, Steven

    2015-01-01

    Approximately 20-25% of all acute strokes occur in the posterior circulation. These strokes can be rather difficult to diagnose because they present in such diverse ways, and can easily be mistaken for more benign entities. A fastidious history, physical exam, high clinical suspicion, and appropriate use of imaging are essential for the emergency physician to properly diagnose and treat these patients. Expert stroke neurologist consultation should be utilized liberally.

  12. [Posterior cortical atrophy].

    PubMed

    Solyga, Volker Moræus; Western, Elin; Solheim, Hanne; Hassel, Bjørnar; Kerty, Emilia

    2015-06-02

    Posterior cortical atrophy is a neurodegenerative condition with atrophy of posterior parts of the cerebral cortex, including the visual cortex and parts of the parietal and temporal cortices. It presents early, in the 50s or 60s, with nonspecific visual disturbances that are often misinterpreted as ophthalmological, which can delay the diagnosis. The purpose of this article is to present current knowledge about symptoms, diagnostics and treatment of this condition. The review is based on a selection of relevant articles in PubMed and on the authors' own experience with the patient group. Posterior cortical atrophy causes gradually increasing impairment in reading, distance judgement, and the ability to perceive complex images. Examination of higher visual functions, neuropsychological testing, and neuroimaging contribute to diagnosis. In the early stages, patients do not have problems with memory or insight, but cognitive impairment and dementia can develop. It is unclear whether the condition is a variant of Alzheimer's disease, or whether it is a separate disease entity. There is no established treatment, but practical measures such as the aid of social care workers, telephones with large keypads, computers with voice recognition software and audiobooks can be useful. Currently available treatment has very limited effect on the disease itself. Nevertheless it is important to identify and diagnose the condition in its early stages in order to be able to offer patients practical assistance in their daily lives.

  13. Persistent occiput posterior.

    PubMed

    Barth, William H

    2015-03-01

    Persistent occiput posterior (OP) is associated with increased rates of maternal and newborn morbidity. Its diagnosis by physical examination is challenging but is improved with bedside ultrasonography. Occiput posterior discovered in the active phase or early second stage of labor usually resolves spontaneously. When it does not, prophylactic manual rotation may decrease persistent OP and its associated complications. When delivery is indicated for arrest of descent in the setting of persistent OP, a pragmatic approach is suggested. Suspected fetal macrosomia, a biparietal diameter above the pelvic inlet or a maternal pelvis with android features should prompt cesarean delivery. Nonrotational operative vaginal delivery is appropriate when the maternal pelvis has a narrow anterior segment but ample room posteriorly, like with anthropoid features. When all other conditions are met and the fetal head arrests in an OP position in a patient with gynecoid pelvic features and ample room anteriorly, options include cesarean delivery, nonrotational operative vaginal delivery, and rotational procedures, either manual or with the use of rotational forceps. Recent literature suggests that maternal and fetal outcomes with rotational forceps are better than those reported in older series. Although not without significant challenges, a role remains for teaching and practicing selected rotational forceps operations in contemporary obstetrics.

  14. Posterior interosseous neuropathy

    PubMed Central

    Kele, Henrich; Xia, Annie; Weiler, Markus; Schwarz, Daniel; Bendszus, Martin; Pham, Mirko

    2016-01-01

    Objective: To investigate the spatial pattern of lesion dispersion in posterior interosseous neuropathy syndrome (PINS) by high-resolution magnetic resonance neurography. Methods: This prospective study was approved by the local ethics committee and written informed consent was obtained from all patients. In 19 patients with PINS and 20 healthy controls, a standardized magnetic resonance neurography protocol at 3-tesla was performed with coverage of the upper arm and elbow (T2-weighted fat-saturated: echo time/repetition time 52/7,020 milliseconds, in-plane resolution 0.27 × 0.27 mm2). Lesion classification of the radial nerve trunk and its deep branch (which becomes the posterior interosseous nerve) was performed by visual rating and additional quantitative analysis of normalized T2 signal of radial nerve voxels. Results: Of 19 patients with PINS, only 3 (16%) had a focal neuropathy at the entry of the radial nerve deep branch into the supinator muscle at elbow/forearm level. The other 16 (84%) had proximal radial nerve lesions at the upper arm level with a predominant lesion focus 8.3 ± 4.6 cm proximal to the humeroradial joint. Most of these lesions (75%) followed a specific somatotopic pattern, involving only those fascicles that would form the posterior interosseous nerve more distally. Conclusions: PINS is not necessarily caused by focal compression at the supinator muscle but is instead frequently a consequence of partial fascicular lesions of the radial nerve trunk at the upper arm level. Neuroimaging should be considered as a complementary diagnostic method in PINS. PMID:27683851

  15. Symptomatic posterior mediastinal angioleiomyoma.

    PubMed

    I, Hoseok; Jeong, Yeon Joo; Choi, Kyung Un; Kim, Yeong-Dae

    2008-08-30

    We report a case of a symptomatic angioleiomyoma in the left posterior mediastinum. A 66-year-old woman presented with left back and flank pain for 6 months. Chest computed tomography (CT) and magnetic resonance imaging (MRI) revealed a well-circumscribed 4.3 cm round mass. The mass was initially diagnosed as nerve sheath tumor, because of her symptoms and its close location to the sympathetic trunk and intercostal nerve. It was uneventfully removed through video-assisted thoracoscopic surgery. The pathology revealed an angioleiomyoma.

  16. 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

  17. 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

  18. Posterior Fossa Meningioma

    PubMed Central

    Saleh, Essam A.; Taibah, Abdel Kader; Achilli, Vittorio; Aristegui, Miguel; Mazzoni, Antonio; Sanna, Mario

    1994-01-01

    Posterior fossa meningioma is the second most common tumor in the cerebellopontine angle. It has a higher rate of postoperative morbidity and mortality compared to acoustic neuroma. Forty posterior fossa meningioma patients managed in our centers were reviewed. Thirty-nine patients were managed surgically with 42 surgical procedures. The approaches used were the translabyrinthine approach in 18 patients (43%), the modified transcochlear in 11 cases (26%), the petro-occipital transsigmoid in 5 cases (12%), the suboccipital in 4 cases (10%), the petro-occipital trassigmoid transcervical in 2 cases (5%), the petro-occipital transsigmoid transtentorial in 1 case (2%), and a subtemporal transtentorial for another case (2%). Facial nerve anatomical integrity was preserved in 87% of procedures but was interrupted in 5 cases, with 4 of the latter subsequently repaired. Total tumor removal was accomplished in 38 cases. A second-stage total tumor removal is planned for the remaining case. There was only one case of perioperative death and no cases of radiological recurrence so far. ImagesFigure 1Figure 2Figure 3Figure 4p206-bFigure 5p207-bFigure 5 PMID:17171173

  19. Arthroscopic Repair of Posterior Bony Bankart Lesion and Subscapularis Remplissage.

    PubMed

    Luedke, Colten; Tolan, Stefan J; Tokish, John M

    2017-06-01

    Posterior shoulder instability with glenoid bone loss has only a fraction of the prevalence of anterior instability. Unlike the latter, there is a paucity of literature regarding the treatment of posterior bony Bankart lesions and even less with concomitant reverse Hill-Sachs lesions. This combination of pathology leads to a difficult situation regarding treatment options. We present our technique for arthroscopic repair of a posterior bony Bankart lesion and reverse Hill-Sachs lesion. The importance of proper portal placement cannot be overstated. By use of the lateral position and strategically placed portals, the posterior bony Bankart lesion and attached labral complex were appropriately mobilized. We reduced the glenoid bone, with the attached capsulolabral complex, to the glenoid rim and performed fixation using a knotless suture anchor. We then placed 2 double-loaded suture anchors into the reverse Hill-Sachs lesion. The sutures were passed creating horizontal mattress configurations that were tied at the end of the procedure, effectively externalizing the humeral head defect. Our technique results in satisfactory fragment reduction, as well as appropriate capsular tension, and effectively prevents the reverse Hill-Sachs lesion from engaging.

  20. Negative participation of the left posterior fascicle in the reentry circuit of verapamil-sensitive idiopathic left ventricular tachycardia.

    PubMed

    Morishima, Itsuro; Nogami, Akihiko; Tsuboi, Hideyuki; Sone, Takahito

    2012-05-01

    Left posterior fascicle and idiopathic Left VT. The left posterior fascicle may be a bystander of the circuit of verapamil-sensitive idiopathic left ventricular tachycardia. During ventricular tachycardia (VT), 3 sequences of potentials were seen at the left posterior septum: diastolic Purkinje potentials propagating from base to apex and presystolic left posterior fascicular potentials and systolic left ventricular (LV) myocardial potentials propagating in the reverse direction. Selective capture of the left posterior fascicle by the sinus beat did not affect the VT cycle length. Entrainment pacing revealed that the retrograde limb of the circuit was not the left posterior fascicle, but the LV myocardium.

  1. 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.

  2. Posterior pole tumor update.

    PubMed

    Ou, Judy I; Wheeler, Sharon M; O'Brien, Joan M

    2002-12-01

    This chapter focuses on the diagnosis and management of choroidal melanoma in light of recent findings from the COMS. Retinoblastoma is emphasized to describe recent trends in primary treatment away from EBRT and toward chemoreduction with local therapy. In addition, vascular and glial tumors of the retina and tumors of the retinal pigment epithelium are described because of the association between these lesions and systemic disease. Recent advances in treatment and genetic testing for these diseases are discussed. Finally, ocular metastasis, intraocular lymphoid tumors, and intraocular leukemia are included because of their importance in determining systemic treatment and prognosis. The chapter gives an overview of important posterior pole tumors and highlights recent developments in the management of each intraocular disease process.

  3. Posterior Probability and Fluctuation Theorem in Stochastic Processes

    NASA Astrophysics Data System (ADS)

    Ohkubo, Jun

    2009-12-01

    A generalization of fluctuation theorems in stochastic processes is proposed. The new theorem is written in terms of posterior probabilities, which are introduced via Bayes’ theorem. In conventional fluctuation theorems, a forward path and its time reversal play an important role, so that a microscopically reversible condition is essential. In contrast, the microscopically reversible condition is not necessary in the new theorem. It is shown that the new theorem recovers various theorems and relations previously known, such as the Gallavotti-Cohen-type fluctuation theorem, the Jarzynski equality, and the Hatano-Sasa relation, when suitable assumptions are employed.

  4. 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.

  5. Posterior sampling with improved efficiency

    SciTech Connect

    Hanson, K.M.; Cunningham, G.S.

    1998-12-01

    The Markov Chain Monte Carlo (MCMC) technique provides a means to generate a random sequence of model realizations that sample the posterior probability distribution of a Bayesian analysis. That sequence may be used to make inferences about the model uncertainties that derive from measurement uncertainties. This paper presents an approach to improving the efficiency of the Metropolis approach to MCMC by incorporating an approximation to the covariance matrix of the posterior distribution. The covariance matrix is approximated using the update formula from the BFGS quasi-Newton optimization algorithm. Examples are given for uncorrelated and correlated multidimensional Gaussian posterior distributions.

  6. [Treatment of recurrent posterior epistaxis].

    PubMed

    Bro, Søren Pauli; Bille, Jesper; Petersen, Kristian Bruun

    2017-08-21

    30% of the patients presenting with epistaxis at emergency wards and otorhinolaryngeal specialist departments have posterior bleeding. Traditional treatment with packing often leads to initial treatment failure, and many patients experience recurrent bleeding within the following month. Recurrent posterior epistaxis should be treated with local electrocautery or endoscopic ligation of the sphenopalatine artery to reduce patient discomfort, hospital stay, risk of treatment failure and recurrence.

  7. 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.

  8. Reversible dementias

    PubMed Central

    Tripathi, Manjari; Vibha, Deepti

    2009-01-01

    In recent years, more attention has been given to the early diagnostic evaluation of patients with dementia which is essential to identify patients with cognitive symptoms who may have treatable conditions. Guidelines suggest that all patients presenting with dementia or cognitive symptoms should be evaluated with a range of laboratory tests, and with structural brain imaging with computed tomography (CT) or magnetic resonance imaging (MRI). While many of the disorders reported as ‘reversible dementias’ are conditions that may well be associated with cognitive or behavioral symptoms, these symptoms are not always sufficiently severe to fulfill the clinical criteria for dementia. Thus, while the etiology of a condition may be treatable it should not be assumed that the associated dementia is fully reversible. Potentially reversible dementias should be identified and treatment considered, even if the symptoms are not sufficiently severe to meet the clinical criteria for dementia, and even if partial or full reversal of the cognitive symptoms cannot be guaranteed. In the literature, the most frequently observed potentially reversible conditions identified in patients with cognitive impairment or dementia are depression, adverse effects of drugs, drug or alcohol abuse, space-occupying lesions, normal pressure hydrocephalus, and metabolic conditions land endocrinal conditions like hypothyroidism and nutritional conditions like vitamin B-12 deficiency. Depression is by far the most common of the potentially reversible conditions. The review, hence addresses the common causes of reversible dementia and the studies published so far. PMID:21416018

  9. 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)

  10. 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)

  11. Combined posterior Bankart lesion and posterior humeral avulsion of the glenohumeral ligaments associated with recurrent posterior shoulder instability.

    PubMed

    Hill, J David; Lovejoy, John F; Kelly, Robert A

    2007-03-01

    Recurrent posterior glenohumeral instability is uncommon and is often misdiagnosed. Damage to the posterior capsule, posteroinferior glenohumeral ligament, and posterior labrum have all been implicated as sources of traumatic posterior instability. We describe a case of traumatic recurrent posterior instability resulting from a posterior Bankart lesion accompanied by posterior humeral avulsion of the glenohumeral ligaments. The Bankart lesion was repaired using a single arthroscopic suture anchor at the glenoid articular margin. The posterior humeral avulsion of the glenohumeral ligaments was addressed with 3 suture anchors placed at the capsular origin at the posterior humeral head. Using these anchors, the posterior capsule was advanced laterally and superiorly for a secure repair. Arthroscopic anatomic reconstruction of both lesions resulted in an excellent clinical outcome.

  12. 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

  13. Assessment of corneal biomechanical behavior under posterior and anterior pressure.

    PubMed

    Yu, Ji-guo; Bao, Fang-jun; Feng, Yi-fan; Whitford, Charles; Ye, Ting; Huang, Yan-bing; Wang, Qin-mei; Elsheikh, Ahmed

    2013-01-01

    To determine the biomechanical response of the rabbit cornea to inflation under posterior and anterior pressure. Twelve Japanese white rabbits were included in the study. A randomly selected eye from each animal was subjected to posterior pressure in an inflation test rig, and the other eye was subjected to anterior pressure after manually reversing its curvature. Specimens were loaded by cycles of pressure up to 40 mmHg, and the experimentally obtained pressure-deformation data were used to derive the stress-strain behavior of each eye using an inverse modeling procedure. The differences between the two groups in corneal thickness, diameter, and intraocular pressure (IOP) were not statistically significant (P=.935, .879 and .368, respectively). Corneas tested under posterior pressure displayed significantly higher stiffness (as measured by the tangent modulus) than those inflated by anterior pressure (P<.001). Cornea is a nonlinear viscoelastic tissue that presents different mechanical properties when tested under posterior and anterior pressure. The determination of the behavior under both forms of pressure could contribute to the construction of accurate finite element simulations of corneal behavior and the correction of tonometric IOP measurements. The difference in mechanical behavior between anteriorly and posteriorly loaded corneas in the study, although significant, could have been partly affected by the changes in microstructure possibly caused by changing corneal form to enable anterior loading. Copyright 2013, SLACK Incorporated.

  14. Posterior Glottic Insufficiency in Children.

    PubMed

    Padia, Reema; Smith, Marshall E

    2017-04-01

    Dysphonia secondary to posterior glottic insufficiency (PGI) can be difficult to identify and correct. Inadequate arytenoid approximation from medial arytenoid erosion results in a breathy, soft voice. The anatomical location of the gap is difficult to correct by vocal fold injection laryngoplasty. This study reviews the presentation, evaluation, and treatment for pediatric patients who were identified with PGI. An Institutional Review Board-approved chart review was performed on all patients who were diagnosed with PGI at our institution from 2013 to 2015. We studied the presentation, workup, and treatment for these patients, including laryngoscopy, parent or patient-based voice impairment ratings, and response to treatment. Seven patients were identified. Erosion of the medial arytenoid was identified on microlaryngoscopy for all of these patients. The patients had suboptimal improvement from injection laryngoplasty. Three patients underwent surgical correction with an endoscopic posterior cricoid reduction laryngoplasty (EPCRL) with significant improvement in voice, assessed by perceptual, laryngoscopic, and patient-based measures. The key diagnostic procedures to identify posterior glottic insufficiency include laryngoscopic findings of a posterior glottal gap, microlaryngoscopy with close inspection of the posterior glottis and medial arytenoids, and suboptimal response to injection laryngoplasty. The EPCRL is an effective procedure to treat dysphonia from PGI.

  15. 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.

  16. The Simplified Posterior Interosseous Flap.

    PubMed

    Cavadas, Pedro C; Thione, Alessandro; Rubí, Carlos

    2016-09-01

    Several technical modifications have been described to avoid complications and simplify dissection. The authors describe some technical tips that make posterior interosseous flap dissection safer and more straightforward. Copyright © 2016 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  17. Children's Understanding of Posterior Probability

    ERIC Educational Resources Information Center

    Girotto, Vittorio; Gonzalez, Michael

    2008-01-01

    Do young children have a basic intuition of posterior probability? Do they update their decisions and judgments in the light of new evidence? We hypothesized that they can do so extensionally, by considering and counting the various ways in which an event may or may not occur. The results reported in this paper showed that from the age of five,…

  18. Children's Understanding of Posterior Probability

    ERIC Educational Resources Information Center

    Girotto, Vittorio; Gonzalez, Michael

    2008-01-01

    Do young children have a basic intuition of posterior probability? Do they update their decisions and judgments in the light of new evidence? We hypothesized that they can do so extensionally, by considering and counting the various ways in which an event may or may not occur. The results reported in this paper showed that from the age of five,…

  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. Reversible Computing

    DTIC Science & Technology

    1980-02-01

    will have been introduced. 9. Reversible celular autemata We shall assume the reader to have some familiarity with the concept of cel- lular...10003 Mr. Kin B. Thcmpson 1 copy Technical Director Information Systems Divisia.i Naval Research Laboratory (OP-91T) Technical Information Division

  1. Reverse mortgages.

    PubMed

    Farnesi, D

    1995-09-01

    Elders and their families are often caught in a financial bind when it comes to paying for much-needed home care services. Reverse mortgages may offer a solution to elderly home care clients who own their homes but have a limited income with which to maintain their independence.

  2. REVERSE OSMOSIS,

    DTIC Science & Technology

    acetate membranes. Mechanisms of the process and porous cellulose acetate membrane technology are briefly reviewed. Based on a general capillary...The reverse osmosis process is discussed with particular reference to systems involving aqueous solutions and Loeb-Sourirajan-type porous cellulose

  3. Reversible cerebral vasoconstriction syndrome.

    PubMed

    Calic, Z; Cappelen-Smith, C; Zagami, A S

    2015-06-01

    Reversible cerebral vasoconstriction syndrome (RCVS) is a clinical-radiological syndrome characterised by severe thunderclap headaches with or without other neurological symptoms and multifocal constriction of cerebral arteries that usually resolves spontaneously within 3 months. Most patients recover completely, but up to 10% have a permanent neurological disability and some even die. Previously RCVS has been described in many clinical contexts and under different names with the term RCVS first being suggested in 2007 to unify the group. The condition may be spontaneous, but in up to 60% of cases it is secondary to another cause, including vasoactive substances (medications and illicit drugs), blood products and the post-partum state. It is believed to have a similar pathophysiological mechanism to the posterior reversible encephalopathy syndrome (PRES), and both can occur in similar clinical contexts and are frequently associated. Treatment options include calcium channel antagonists. RCVS occurs in a broad range of clinical situations making it an increasingly recognised condition about which doctors in various specialties need to be aware. © 2014 Royal Australasian College of Physicians.

  4. Dioptric changes in eyes with reversed intraocular lenses.

    PubMed

    Nawa, Yoshiaki; Okamoto, Masahiro; Tsuji, Hideyuki; Ueda, Tetsuo; Kanzaki, Mamiko; Hara, Yoshiaki

    2005-03-01

    To theoretically calculate refractive changes in eyes with reversed intraocular lenses (IOLs). Nara Medical University, Nara, Japan. With the ray-tracing method, the refractive changes in a theoretical eye model with a reversed IOL in the capsular bag were calculated. Data for 3 models, anterior biconvex (MA60AC, Alcon), posterior biconvex (MA60BM, Alcon), and convex plano (UV2565T, Menicon), were provided by the manufacturer and used in the analysis. Using the assumption that the axial length varied from 22 to 27 mm, the anterior-biconvex IOLs elicited small refractive changes when reversed. The posterior-biconvex IOLs elicited a significant myopic shift (up to 0.90 diopter [D]) when reversed. The convex-plano IOLs elicited a significant hyperopic shift (up to 2.01 D) when reversed. Anterior-biconvex IOLs with similar anterior and posterior radii of curvature will not cause large diopter surprises when reversed. High-power posterior-convex IOLs will cause significant myopic diopter surprises when reversed. Both these changes shift toward myopic if the postoperative anterior chamber depth (ACD) becomes shallow. Medium- to high-power convex-plano IOLs will cause a large hyperopic shift when reversed. This hyperopic shift decreases if the postoperative ACD becomes shallower.

  5. A New Variant of Posterior Canal Benign Paroxysmal Positional Vertigo: A Nonampullary or Common Crus Canalolithiasis

    PubMed Central

    Yetiser, Sertac

    2015-01-01

    Clockwise or counterclockwise, rotational, upbeating nystagmus is seen in patients with posterior canal benign paroxysmal positional vertigo during left or right head-hanging test, respectively. Rotating of nystagmus in opposite direction to the ear tested or even reversal of initial positioning rotational nystagmus is not usual and has never been reported before. We propose a new variant of posterior canal benign paroxysmal positional vertigo due to unusual behavior and location of the otoliths inside the membranous labyrinth. Unexpected rotational direction may lead to confusion about the site. The examiner should be aware of this abnormal or atypical variant of posterior canal benign paroxysmal positional vertigo. PMID:26114003

  6. Exploring the brain through posterior hypothalamus surgery for aggressive behavior.

    PubMed

    Rizzi, Michele; Trezza, Andrea; Messina, Giuseppe; De Benedictis, Alessandro; Franzini, Angelo; Marras, Carlo Efisio

    2017-09-01

    Neurological surgery offers an opportunity to study brain functions, through either resection or implanted neuromodulation devices. Pathological aggressive behavior in patients with intellectual disability is a frequent condition that is difficult to treat using either supportive care or pharmacological therapy. The bulk of the laboratory studies performed throughout the 19th century enabled the formulation of hypotheses on brain circuits involved in the generation of emotions. Aggressive behavior was also studied extensively. Lesional radiofrequency surgery of the posterior hypothalamus, which peaked in the 1970s, was shown to be an effective therapy in many reported series. As with other surgical procedures for the treatment of psychiatric disorders, however, this therapy was abandoned for many reasons, including the risk of its misuse. Deep brain stimulation (DBS) offers the possibility of treating neurological and psychoaffective disorders through relatively reversible and adaptable therapy. Deep brain stimulation of the posterior hypothalamus was proposed and performed successfully in 2005 as a treatment for aggressive behavior. Other groups reported positive outcomes using target and parameter settings similar to those of the original study. Both the lesional and DBS approaches enabled researchers to explore the role of the posterior hypothalamus (or posterior hypothalamic area) in the autonomic and emotional systems.

  7. [Reversible cerebral vasoconstriction syndrome].

    PubMed

    Néel, A; Guillon, B; Auffray-Calvier, E; Hello, M; Hamidou, M

    2012-10-01

    The reversible cerebral vasoconstriction syndrome (RCVS) is an under-estimated transient acute cerebrovascular disorder. It has long been mistaken as central nervous system vasculitis whereas it is now believed to result from an acute but prolonged vasospasm of cerebral arteries. This disorder can be precipitated by postpartum or vasoactive drug. However, it occurs spontaneously in a significant number of cases. The characteristic clinico-radiological presentation and disease course of the RCVS has been delineated only recently. Mean age at onset is 40-45 years, with a female predominance. A provocative factor can be identified in 12-60% out of the patients. Clinical presentation is predominantly marked by recurrent thunderclap headaches, but can be complicated with focal neurological deficit or seizures. Brain imaging is normal in most cases, but can reveal hemorrhagic or ischemic complications. Cortical subarachnoid hemorrhage is a suggestive finding. A posterior reversible encephalopathy syndrome (PRES) can be seen occasionally. Cerebral angiography reveals multifocal arterial narrowing with string and bead appearance. Cerebrospinal fluid reveals no or mild abnormalities. The disease resumes spontaneously within several days to weeks, whereas vasoconstriction reverses within 1 to 3 months. This clinico-radiological presentation should be promptly recognized in order to avoid unnecessary investigations and aggressive treatment, and lead to search for a triggering factor. Further studies are required in order to clarify the precipitating role of several drugs, and clinical trials are needed to reduce the occurrence of strokes. Copyright © 2012 Société nationale française de médecine interne (SNFMI). Published by Elsevier SAS. All rights reserved.

  8. 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.

  9. Distortions of posterior visual space.

    PubMed

    Phillips, Flip; Voshell, Martin G

    2009-01-01

    The study of spatial vision is a long and well traveled road (which, of course, converges to a vanishing point at the horizon). Its various distortions have been widely investigated empirically, and most concentrate, pragmatically, on the space anterior to the observer. The visual world behind the observer has received relatively less attention and it is this perspective the current experiments address. Our results show systematic perceptual distortions in the posterior visual world when viewed statically. Under static viewing conditions, observer's perceptual representation was consistently 'spread' in a hyperbolic fashion. Directions to distant, peripheral locations were consistently overestimated by about 11 degrees from the ground truth and this variability increased as the target was moved toward the center of the observer's back. The perceptual representation of posterior visual space is, no doubt, secondary to the more immediate needs of the anterior visual world. Still, it is important in some domains including certain sports, such as rowing, and in vehicular navigation.

  10. 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

  11. Posterior commissure of the human larynx revisited.

    PubMed

    Tucker, John A; Tucker, Sean T

    2010-05-01

    The existence of the posterior commissure (PC) of the human larynx has been disputed (Hirano M, Sato K, et al. The posterior glottis. Trans Am Laryngol Assoc. 1986;107:70-75). "The term posterior commissure has no relevance to anatomical structure. The term commissure means a joining together. The bilateral vocal folds never join at their posterior ends. The posterior aspect of the glottis is a wall. The posterior lateral aspect of the posterior glottis is also the lateral wall of the posterior glottis" (Hirano M, Sato K, et al. The posterior glottis. Trans Am Laryngol Assoc. 1986;107:70-75). This study is intended to clarify the development of anatomical and morphological aspects of the PC in conjunction with a clinical classification of the larynx in sagittal view. This study uses human embryo and fetal laryngeal sections from the Carnegie Collection of Human Embryos (the world standard) and whole organ laryngeal sections from the Tucker Laryngeal Fetal Collection. Correlation of histologic and gross anatomical structure is made with the Hirano et al atlas, the Vidić Photographic Atlas of the Human Body, and the O'Rahilly Embryonic Atlas. Embryologic data clearly describe and illustrate the posterior union of the cricoid cartilage with formation of the PC. The anatomical functional aspects of the posterior lateral cricoid lamina as the supporting buttress of the articulating arytenoid cartilages are illustrated.

  12. 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

  13. Posterior tibial slope and femoral sizing affect posterior cruciate ligament tension in posterior cruciate-retaining total knee arthroplasty.

    PubMed

    Kuriyama, Shinichi; Ishikawa, Masahiro; Nakamura, Shinichiro; Furu, Moritoshi; Ito, Hiromu; Matsuda, Shuichi

    2015-08-01

    During cruciate-retaining total knee arthroplasty, surgeons sometimes encounter increased tension of the posterior cruciate ligament. This study investigated the effects of femoral size, posterior tibial slope, and rotational alignment of the femoral and tibial components on forces at the posterior cruciate ligament in cruciate-retaining total knee arthroplasty using a musculoskeletal computer simulation. Forces at the posterior cruciate ligament were assessed with the standard femoral component, as well as with 2-mm upsizing and 2-mm downsizing in the anterior-posterior dimension. These forces were also determined with posterior tibial slope angles of 5°, 7°, and 9°, and lastly, were measured in 5° increments when the femoral (tibial) components were positioned from 5° (15°) of internal rotation to 5° (15°) of external rotation. Forces at the posterior cruciate ligament increased by up to 718N with the standard procedure during squatting. The 2-mm downsizing of the femoral component decreased the force at the posterior cruciate ligament by up to 47%. The 2° increment in posterior tibial slope decreased the force at the posterior cruciate ligament by up to 41%. In addition, posterior cruciate ligament tension increased by 11% during internal rotation of the femoral component, and increased by 18% during external rotation of the tibial component. These findings suggest that accurate sizing and bone preparation are very important to maintain posterior cruciate ligament forces in cruciate-retaining total knee arthroplasty. Care should also be taken regarding malrotation of the femoral and tibial components because this increases posterior cruciate ligament tension. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. 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

  15. 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

  16. Posterior peritoneal recesses: assessment using CT

    SciTech Connect

    Rubenstein, W.A.; Auh, Y.H.; Zirinsky, K.; Kneeland, J.B.; Whalen, J.P.; Kazam, E.

    1985-08-01

    Intraperitoneal compartments may extend posteriorly to the level of known retroperitoneal structures at several locations within the abdomen. These locations include the posterior subhepatic or hepatorenal space, the splenorenal space, the retropancreatic recess, the paracolic gutters, and the pararectal fossae. Because of their posterior location, fluid collections within these compartments may be mistaken radiologically for retroperitoneal masses. The sectional anatomy of these spaces and particularly their appearance on computed tomographic scans, are illustrated in this paper.

  17. Posterior ankle impingement in the dancer.

    PubMed

    Moser, Brad R

    2011-01-01

    Dancers spend a lot of time in the relevé position in demi-pointe and en pointe in their training and their careers. Pain from both osseous and soft tissue causes may start to occur in the posterior aspect of their ankle. This article reviews the potential causes of posterior ankle impingement in dancers. It will discuss the clinical evaluation of a dancer and the appropriate workup and radiographic studies needed to further evaluate a dancer with suspected posterior ankle impingement.

  18. Imaging of the Posterior Skull Base.

    PubMed

    Job, Joici; Branstetter, Barton F

    2017-01-01

    The posterior skull base can be involved by a variety of pathologic processes. They can be broadly classified as: traumatic, neoplastic, vascular, and inflammatory. Pathology in the posterior skull base usually involves the lower cranial nerves, either as a source of pathology or a secondary source of symptoms. This review will categorize pathology arising in the posterior skull base and describe how it affects the skull base itself and surrounding structures. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Treatment of Locked Posterior Shoulder Dislocation With Bone Defect.

    PubMed

    Khira, Yousuf M; Salama, Adel M

    2017-03-14

    Locked posterior shoulder dislocation is an uncommon condition and is associated with a reverse Hill-Sachs lesion in 50% of cases. The condition is likely to occur in cases of violent trauma, seizures, or electric shock. Unrecognized dislocation with humeral head fracture affects joint function and humeral head vascularity and may lead to chronic instability, osteonecrosis, and osteoarthritis. A group of 12 patients, including 10 men and 2 women, with neglected locked posterior shoulder dislocation with a reverse Hill-Sachs lesion were treated with the modified McLaughlin technique. The added bone graft from the iliac crest was impacted in the defect and fixed with screws. Mean follow-up was 30 months (range, 24-48 months). The range of forward flexion was 150˚ to 175˚ (average, 165˚), external rotation ranged from 60˚ to 80˚ (average, 75˚), internal rotation ranged from 40˚ to 60˚ (average, 50˚), and average abduction was 150˚ (range, 145˚-160˚). The modified University of California Los Angeles (UCLA) scoring system was used for postoperative clinical evaluation. Total UCLA scores immediately postoperatively ranged from 22 to 28 points (average, 26.5 points) and averaged 30 points (range, 28-33 points) at last follow-up. No recurrence of dislocation occurred during the follow-up period. Of the study patients, 10 returned to their previous job and 2 modified their manual work. The modified McLaughlin technique with added iliac crest bone graft to fill the defect and prevent humeral head deformity is a successful technique for the treatment of patients with chronic locked posterior shoulder dislocation. [Orthopedics. 201x; xx(x):xx-xx.].

  20. 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.

  1. 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. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Developmental abnormalities of the posterior pituitary gland.

    PubMed

    di Iorgi, Natascia; Secco, Andrea; Napoli, Flavia; Calandra, Erika; Rossi, Andrea; Maghnie, Mohamad

    2009-01-01

    While the molecular mechanisms of anterior pituitary development are now better understood than in the past, both in animals and in humans, little is known about the mechanisms regulating posterior pituitary development. The posterior pituitary gland is formed by the evagination of neural tissue from the floor of the third ventricle. It consists of the distal axons of the hypothalamic magnocellular neurones that shape the neurohypophysis. After its downward migration, it is encapsulated together with the ascending ectodermal cells of Rathke's pouch which form the anterior pituitary. By the end of the first trimester, this development is completed and vasopressin and oxytocin can be detected in neurohypophyseal tissue. Abnormal posterior pituitary migration such as the ectopic posterior pituitary lobe appearing at the level of median eminence or along the pituitary stalk have been reported in idiopathic GH deficiency or in subjects with HESX1, LHX4 and SOX3 gene mutations. Another intriguing feature of abnormal posterior pituitary development involves genetic forms of posterior pituitary neurodegeneration that have been reported in autosomal-dominant central diabetes insipidus and Wolfram disease. Defining the phenotype of the posterior pituitary gland can have significant clinical implications for management and counseling, as well as providing considerable insight into normal and abnormal mechanisms of posterior pituitary development in humans.

  3. Unilateral posterior crossbite and mastication.

    PubMed

    Rilo, Benito; da Silva, José Luis; Mora, María Jesús; Cadarso-Suárez, Carmen; Santana, Urbano

    2007-05-01

    This study was designed to characterize masticatory-cycle morphology, and distance of the contact glide in the closing masticatory stroke, in adult subjects with uncorrected unilateral posterior crossbite (UPXB), comparing the results obtained with those obtained in a parallel group of normal subjects. Mandibular movements (masticatory movements and laterality movements with dental contact) were registered using a gnathograph (MK-6I Diagnostic System) during unilateral chewing of a piece of gum. Traces were recorded on the crossbite and non-crossbite sides in the crossbite group, and likewise on both sides in the non-crossbite group. Mean contact glide distance on the crossbite side in the UPXB group was significantly lower than in the control group (p<0.001), and mean contact glide distance on the non-crossbite side in the UPXB group was significantly lower than in the control group (p=0.042). Cycle morphology was abnormal during chewing on the crossbite side, with the frequency distribution of cycle types differing significantly from that for the noncrossbite side and that for the control group (p<0.001). Patients with crossbite showed alterations in both contact glide distances and masticatory cycle morphology. These alterations are probably adaptive responses allowing maintenance of adequate masticatory function despite the crossbite.

  4. [Posterior uveitis: sarcoidosis or tuberculosis].

    PubMed

    Ness, T; Virchow, J C

    2001-02-01

    To demonstrate the difficulties of the differential diagnosis between tuberculosis and sarcoidosis as the cause of posterior uveitis. A 56-year-old woman suffered from bilateral anterior uveitis, snow-ball like infiltrates in the vitreous, and peripheral retinochoroidal granulomas with marked exudation shown in fluorescein angiography. Angiotensin-converting enzyme, as a marker of sarcoidosis, was elevated; the tuberculin test, however, was negative. Chest X-ray revealed an infiltrate and numerous smaller granulomas. The presumptive diagnosis was sarcoidosis. Surprisingly, in the biopsy of the pulmonal lesion tubercle bacilli were detected by Ziehl-Neelsen staining. Thus, a diagnosis of pulmonal and also retinochoroidal tuberculosis was made. After tuberculostatic therapy the choroidal lesions healed off. In a second case, a 30-year-old man suffered from bilateral panuveitis with candle wax exudates near the retinal vessels. Chest X-ray revealed lymphomas in the hilus, and the lymph node biopsy showed granulomas with epitheloid cells, indicating sarcoidosis. Detection of mycobacterium tuberculosis by culture or histological criteria was negative. Only in the PCR was mycobacterium tuberculosis DNA detectable. Tuberculostatic therapy had no benefit. Under therapy with steroids, however, pulmonal and ophthalmologic findings rapidly disappeared. The difficult differential diagnosis between sarcoidosis and tuberculosis cannot always be made by laboratory tests or diagnostic imaging alone. Clinical manifestations, including response to therapy, are essential.

  5. Posterior repair and sexual function

    PubMed Central

    Komesu, Yuko M.; Rogers, Rebecca G.; Kammerer-Doak, Dorothy N.; Barber, Matthew D.; Olsen, Ambre L.

    2011-01-01

    OBJECTIVE The purpose of this study was to determine the effect of posterior repair (PR) on sexual function in patients who have undergone incontinence and/or pelvic reconstructive surgery. STUDY DESIGN A cohort study of women who underwent incontinence and/or prolapse surgery was performed. Participants completed the pelvic organ prolapse urinary incontinence sexual questionnaire (PISQ) before and after the operation. PISQ scores were compared between women who underwent PR and women who did not. RESULTS Of 73 study participants, 30 women underwent PR; 43 women did not (no PR). Although there was no difference in dyspareunia between groups pre-op, dyspareunia prevalence post-op was significantly lower in the no PR group. Preoperative PISQ scores were similar between groups. After the operation, both groups significantly improved their PISQ scores, without a difference between groups. CONCLUSION Although the incidence of dyspareunia differed between PR and no PR groups, overall improvement in sexual function was reflected in improved total PISQ scores that occurred irrespective of PR performance. PMID:17618777

  6. Reconstruction of posterior trunk defects.

    PubMed

    Ramasastry, S S; Schlechter, B; Cohen, M

    1995-01-01

    A high rate of success can be expected in the management of posterior trunk defects with muscle flaps. The surgeon has to adhere closely to the basic reconstructive principles of adequate debridement of all necrotic or devitalized tissues; management of infection with local wound care and appropriate antibiotic therapy; and coverage with well-vascularized tissue to obliterate any residual dead space and to cover bone grafts, orthopedic hardware, and vital structures such as the dura and spinal cord. Flap selection is also of paramount importance for success, and only muscles with appropriate arc of rotation, vascularity (vascular pedicles outside the field of radiation injury, or intact vascularity following previous procedures) and bulk should be used. Adequate flap mobilization to obtain a tension-free closure and judicious use of drains and perioperative antibiotic agents are essential. Occasionally, microvascular free-tissue transfer may be necessary if local flaps are unavailable. The complications of flap reconstruction include partial flap loss, persistent dead space for lack of adequate muscle bulk, and persistent infection. Debridement and re-advancement of the flap is adequate in most cases. If there is significant or total flap loss, however, a second flap reconstruction is often necessary to obliterate the dead space and protect vital structures.

  7. Meibography for eyes with posterior blepharitis.

    PubMed

    AlDarrab, Abdulrahman; Alrajeh, Mohammed; Alsuhaibani, Adel H

    2017-01-01

    To study the effect of posterior blepharitis on meibomian glands using infrared meibography and to correlate the results with tear film parameters. This is a prospective cohort study. The study included eyes from two groups: 86 eyes of healthy volunteers' eyes and 72 eyes with posterior blepharitis. Participants were examined, and diagnosis of posterior blepharitis was achieved clinically based on signs of posterior blepharitis. Clinical assessment of dryness was performed including slit lamp examination looking for signs of posterior blepharitis, tear breakup time (TBUT), superficial punctate keratopathy (SPK), Schirmer II test (with anesthesia) and meibum score. Non-contact meibography was performed for both upper and lower eyelids using the meibo-grade system which involved distortion of meibomian gland, shortening and dropout. Lid margin abnormalities (Telangiectasia, lid margin swelling and hyperemia) were all significantly higher in the posterior blepharitis group. SPK, meibum score, meibography dropout, distortion, shortening, and total meibography were all significantly higher in the posterior blepharitis group as well as meibum score (P value < 0.001). TBUT was significantly shorter in the posterior blepharitis group (P value < 0.001). There was no significant difference between the two groups in Schirmer's II test. Meibography can be a helpful non-invasive tool for the clinical evaluation of the extent of the anatomical damage in patients having meibomian glands loss due to posterior blepharitis. Knowing the extent of damage in meibomian glands may help in selecting the appropriate treatment modality and expect the response to treatment in patients with posterior blepharitis.

  8. Simultaneous bilateral posterior dislocation of the shoulder: diagnostic problems and management. A case report.

    PubMed

    Iosifidis, Michael I; Giannoulis, Ioannis; Traios, Stavros; Giantsis, Georgios

    2006-08-01

    We present the case of a patient who sustained simultaneous bilateral posterior dislocation of the shoulder after a possible epileptic fit. The confirmation of the diagnosis was reached only by a computed tomography (CT) scan, after the clinical suspicion. Under general anesthesia, close reduction of both shoulder dislocations was done. Posterior dislocation of the shoulder-especially the bilateral one-is very rare. When the history describes an electric shock or convulsive seizure, any shoulder injury demands a careful clinical and radiological evaluation. It is usually associated with reverse Hill-Sachs lesion (an impression defect of the anteromedial aspect of the humeral head), in which the size determines the treatment options.

  9. Recurrent posterior shoulder instability. Diagnosis and treatment.

    PubMed

    Pollock, R G; Bigliani, L U

    1993-06-01

    Recurrent posterior glenohumeral instability is regarded as a difficult problem to diagnose and treat. A careful history and physical examination are the most helpful tools in making this diagnosis. A positive posterior stress test, demonstrable posterior subluxation, and a sulcus sign are frequently present on examination. Special roentgenographic studies, such as the computerized arthrotomography (arthro-CT) scan, may be used in cases in which plain roentgenographs suggest bony glenoid abnormalities. When conservative therapy fails, there is no consensus on the operative treatment. Procedures that address the soft tissues, such as capsulorrhaphy and posterior labral repair, as well as those that alter the bony geometry of the joint, such as posterior bone blocks and glenoid or humeral osteotomies, have been described. Capsular laxity is the most common pathologic finding in the authors' experience, and they favor the use of a posterior-inferior capsular shift procedure to correct this problem. Augmentation of the repair with a posterior bone block is reserved for unusual cases, such as when glenoid hypoplasia is present or in certain revision situations.

  10. Posterior labral injury in contact athletes.

    PubMed

    Mair, S D; Zarzour, R H; Speer, K P

    1998-01-01

    Nine athletes (seven football offensive linemen, one defensive lineman, and one lacrosse player) were found at arthroscopy to have posterior labral detachment from the glenoid. In our series, this lesion is specific to contact athletes who engage their opponents with arms in front of the body. All patients had pain with bench pressing and while participating in their sport, diminishing their ability to play effectively. Conservative measures were ineffective in relieving their symptoms. Examination under anesthesia revealed symmetric glenohumeral translation bilaterally, without evidence of posterior instability. Treatment consisted of glenoid rim abradement and posterior labral repair with a bioabsorbable tack. All patients returned to complete at least one full season of contact sports and weightlifting without pain (minimum follow-up, > or = 2 years). Although many injuries leading to subluxation of the glenohumeral joint occur when an unanticipated force is applied, contact athletes ready their shoulder muscles in anticipation of impact with opponents. This leads to a compressive force at the glenohumeral joint. We hypothesize that, in combination with a posteriorly directed force at impact, the resultant vector is a shearing force to the posterior labrum and articular surface. Repeated exposure leads to posterior labral detachment without capsular injury. Posterior labral reattachment provides consistently good results, allowing the athlete to return to competition.

  11. 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

  12. Treatment implications of posterior fossa ependymoma subgroups.

    PubMed

    Ramaswamy, Vijay; Taylor, Michael D

    2016-11-15

    Posterior fossa ependymoma comprises two distinct molecular entities, ependymoma_posterior fossa A (EPN_PFA) and ependymoma_posterior fossa B (EPN_PFB), with differentiable gene expression profiles. As yet, the response of the two entities to treatment is unclear. To determine the relationship between the two molecular subgroups of posterior fossa ependymoma and treatment, we studied a cohort of 820 patients with molecularly profiled, clinically annotated posterior fossa ependymomas. We found that the strongest predictor of poor outcome in patients with posterior fossa ependymoma across the entire age spectrum was molecular subgroup EPN_PFA, which was recently reported in the paper entitled "Therapeutic impact of cytoreductive surgery and irradiation of posterior fossa ependymoma in the molecular era: a retrospective multicohort analysis" in the Journal of Clinical Oncology. Patients with incompletely resected EPN_PFA tumors had a very poor outcome despite receiving adjuvant radiation therapy, whereas a substantial proportion of patients with EPN_PFB tumors can be cured with surgery alone.

  13. Outcome of Posterior Tibial Plateau Fixation.

    PubMed

    Jiwanlal, Aneel; Jeray, Kyle James

    2016-01-01

    Isolated posterior tibial plateau fractures are rare injuries that encompass a wide variety of fracture patterns. Based on the variation in fracture pattern, the surgical approach varies, with both anterior and posterior approaches described for surgical fixation. Postoperative protocol also varies among studies. The aim of this article is to summarize the outcomes related to posterior column tibial plateau fractures. The papers reviewed, primarily small retrospective case series, showed functional knee range of motion is preserved, a low incidence of wound complications, and patient outcome scores comparable to other reported lower extremity injury outcome scores. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  14. Posterior retroperitoneoscopic approach to the adrenal arteries.

    PubMed

    Lotti, Marco; Giulii Capponi, Michela

    2016-12-01

    Differently from transperitoneal adrenalectomy, with the posterior retroperitoneoscopic approach adrenal arteries are dissected first [1, 2]. Knowledge of their position is pivotal as they are covered by peri-adrenal fat [3, 4]. Four posterior retroperitoneoscopic adrenalectomies were selected, in which adrenal arteries are dissected to show their path and how they can be localized among peri-adrenal fat. A video is presented herein, which focuses on surgical anatomy of adrenal arteries when approached during a posterior retroperitoneoscopic adrenalectomy. Details about relative positions between adrenal arteries and adjacent structures are considered and shown during their dissection. The posterior retroperitoneoscopic approach offers a direct view of adrenal arteries and allows for their exposure and safe division in the early steps of adrenalectomy.

  15. Posterior cruciate ligament (PCL) injury - aftercare

    MedlinePlus

    Adib F, Curtis C, Bienkowski P Micheli LJ. Posterior cruciate ligament sprain. In: Frontera WR, Silver JK, Rizzo TD Jr, eds. Essentials of Physical Medicine and Rehabilitation: Musculoskeletal Disorders, ...

  16. 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

  17. [Posterior cortical atrophy (Benson-syndrome)].

    PubMed

    Rózsa, Anikó; Szilvássy, Ildikó; Kovács, Krisztina; Boór, Krisztina; Gács, Gyula

    2010-01-30

    We present the characteristics of posterior cortical atrophy--a very rare cortical dementia--in a 69 year old woman's case. Our patient's symptoms began with a visual problem which was initially explained by ophthalmological disorder. After neurological exam visual agnosia was diagnosed apart from other cognitive disorder (alexia without agraphia, acalculia, prosopagnosia, constructional disorder, clock-time recognition disorder, dressing apraxia, visuospatial disorientation). The brain MRI showed bilateral asymmetric parieto-occipital atrophy which is characteristic of posterior cortical atrophy.

  18. Gibbs Sampling for Marginal Posterior Expectations

    DTIC Science & Technology

    1991-11-19

    Achcar and Smith (1989) shows that performance of the Laplace method is often very sensitive to parametrization. Morris (1988) offers expansions based on...Berkeley Symp. 1, 453-468. Lindley, D.V. (1980). "Approximate Bayesian Methods" in Bayesian Statistics, J.M. Bernardo, M.H. DeGroot , D.V. Lindley...A.F.M. Smith, University Press, Valencia, Spain. Morris , C. "Approximating Posterior Distributions and Posterior Moments" In: Bayesian Statistics 3, J.M

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

    PubMed

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

    2015-11-05

    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.

  20. Vertigo due to posterior circulation stroke.

    PubMed

    Kim, Ji Soo; Lee, Hyung

    2013-07-01

    Stroke in the distribution of the posterior circulation may present as acute onset spontaneous vertigo and imbalance. Although vertigo due to posterior circulation stroke is usually associated with other neurologic symptoms or signs, small infarcts in the cerebellum or brainstem can present with vertigo without other localizing symptoms. Approximately 17% of patients with isolated posterior inferior cerebellar artery territory infarction presented with isolated vertigo, nystagmus, and postural unsteadiness. A head impulse test can differentiate acute isolated vertigo associated with cerebellar stroke from more benign disorders involving the inner ear. Sometimes acute isolated audiovestibular loss can be the initial symptom of impending posterior circulation ischemic stroke (particularly within the territory of the anterior inferior cerebellar artery). In this case, evaluation of isolated audiovestibular loss may prevent the progression of acute vertigo and hearing loss into more widespread areas of infarction in the posterior circulation. In this article, the clinical syndromes and signs of acute vestibular syndrome due to posterior circulation stroke involving the brainstem and cerebellum are summarized.

  1. International Comparative Evaluation of Knee Replacement with Fixed or Mobile-Bearing Posterior-Stabilized Prostheses

    PubMed Central

    Graves, Stephen; Sedrakyan, Art; Baste, Valborg; Gioe, Terence J.; Namba, Robert; Cruz, Olga Martínez; Stea, Susanna; Paxton, Elizabeth; Banerjee, Samprit; Isaacs, Abby J.; Robertsson, Otto

    2014-01-01

    Background: Posterior-stabilized total knee prostheses were introduced to address instability secondary to loss of posterior cruciate ligament function, and they have either fixed or mobile bearings. Mobile bearings were developed to improve the function and longevity of total knee prostheses. In this study, the International Consortium of Orthopaedic Registries used a distributed health data network to study a large cohort of posterior-stabilized prostheses to determine if the outcome of a posterior-stabilized total knee prosthesis differs depending on whether it has a fixed or mobile-bearing design. Methods: Aggregated registry data were collected with a distributed health data network that was developed by the International Consortium of Orthopaedic Registries to reduce barriers to participation (e.g., security, proprietary, legal, and privacy issues) that have the potential to occur with the alternate centralized data warehouse approach. A distributed health data network is a decentralized model that allows secure storage and analysis of data from different registries. Each registry provided data on mobile and fixed-bearing posterior-stabilized prostheses implanted between 2001 and 2010. Only prostheses associated with primary total knee arthroplasties performed for the treatment of osteoarthritis were included. Prostheses with all types of fixation were included except for those with the rarely used reverse hybrid (cementless tibial and cemented femoral components) fixation. The use of patellar resurfacing was reported. The outcome of interest was time to first revision (for any reason). Multivariate meta-analysis was performed with linear mixed models with survival probability as the unit of analysis. Results: This study includes 137,616 posterior-stabilized knee prostheses; 62% were in female patients, and 17.6% had a mobile bearing. The results of the fixed-effects model indicate that in the first year the mobile-bearing posterior-stabilized prostheses had

  2. 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

  3. Spatio-Temporal Updating in the Left Posterior Parietal Cortex

    PubMed Central

    Wada, Makoto; Takano, Kouji; Ikegami, Shiro; Ora, Hiroki; Spence, Charles; Kansaku, Kenji

    2012-01-01

    Adopting an unusual posture can sometimes give rise to paradoxical experiences. For example, the subjective ordering of successive unseen tactile stimuli delivered to the two arms can be affected when people cross them. A growing body of evidence now highlights the role played by the parietal cortex in spatio-temporal information processing when sensory stimuli are delivered to the body or when actions are executed; however, little is known about the neural basis of such paradoxical feelings resulting from such unusual limb positions. Here, we demonstrate increased fMRI activation in the left posterior parietal cortex when human participants adopted a crossed hands posture with their eyes closed. Furthermore, by assessing tactile temporal order judgments (TOJs) in the same individuals, we observed a positive association between activity in this area and the degree of reversal in TOJs resulting from crossing arms. The strongest positive association was observed in the left intraparietal sulcus. This result implies that the left posterior parietal cortex may be critically involved in monitoring limb position and in spatio-temporal binding when serial events are delivered to the limbs. PMID:22768126

  4. Posterior urethral polyp with type I posterior urethral valves: a rare association in a neonate.

    PubMed

    Kesan, Krushnakumar V; Gupta, Rahul Kumar; Kothari, Paras; Gupta, Abhaya; Mudkhedkar, Kedar; Kamble, Ravikiran; Dikshit, K Vishesh

    2014-06-01

    Urethral polyp is a rare cause of bladder outlet obstruction, voiding dysfunction, and hematuria in the pediatric age group. Urethral polyps are rarely associated with other congenital urinary tract anomalies. In this study, we report a case of solitary posterior urethral polyp with type I posterior urethral valve in a 7-day-old neonate presented with urinary retention and deranged renal function. The polyp was diagnosed on cystoscopy. Transurethral resection of the polyp with posterior urethral valve fulguration was performed. Pathologic assessment revealed a fibroepithelial lesion, which was consistent with congenital posterior urethral polyp.

  5. Arthroscopic classification of posterior labrum glenoid insertion.

    PubMed

    Nourissat, G; Radier, C; Aim, F; Lacoste, S

    2014-04-01

    We performed a prospective arthroscopic study to explore the variability of the posterior labrum glenoid insertion. We aimed to classify the insertions and to explore whether these insertions can be identified by pre-operative arthro-CT scan. From January to December 2011, 86 patients were prospectively included in the current study. During arthroscopy, anterior labrum was evaluated and posterior labrum was assessed in 3 different locations: superior, medial, and inferior. For each segment, the labrum was considered normally inserted (directly to the glenoid cartilage), medialized (inserted at the posterior part of the glenoid bone, without direct contact with the cartilage), torn (macroscopic degenerative changes, tears, fragments) or absent (agenesis). Imaging was analyzed segment by segment by an experienced osteoarticular radiologist, using the same classification. Four types of posterior labrum insertions were identified. Type 1, 60% of the cases, corresponded to a posterior labrum totally inserted in the glenoid, with direct contact with the cartilage. Type 2, 20% of the cases, represented medialized insertion of the superior segment. Type 3, 15% of the cases, represented an associated medialization of the superior and medial segment of the posterior labrum. Type 4 is a medialized insertion of the all-posterior labrum. Fifty-six shoulders were used for arthro-CT and arthroscopy correlation: for the superior segment (n=22/56), the sensitivity of arthro-CT to identify an abnormal insertion when the labrum is medialized was 68.18%, specificity 70.59%, positive predictive value (PPV) 60%, and negative predictive value (NPV) 77.42%. For the medial segment (n=16/56), the sensitivity of arthro-CT to identify an abnormal insertion when the labrum is medialized was 81.25%, specificity 57.50%, PPV 43.33% and NPV 88.46%. For the inferior segment (n=5/56), the sensitivity was 100%, specificity 47.60%, PPV 15.63% and NPV 100%. The current study points out the high

  6. Transnasal endoscopic repair of posterior table fractures.

    PubMed

    Chaaban, Mohamad R; Conger, Bryant; Riley, Kristen O; Woodworth, Bradford A

    2012-12-01

    Conventional treatment of frontal sinus posterior table fractures has included osteoplastic flap or cranialization procedures despite considerable advances in endoscopic technique and experience. The objective of the current study was to evaluate outcomes of frontal sinus fractures involving the posterior table managed using endoscopic approaches. Prospective cohort. Tertiary care, academic university hospital. Prospective evaluation of patients with posterior table fractures was performed. Data were collected regarding demographics, etiology, technique, operative site, length involving the posterior table, size of the skull base defect, complications, and clinical follow-up. Thirteen patients (average age 37 years) with posterior table fractures were treated using endoscopic techniques from 2008 to 2012. Mean follow-up time was 68 weeks (range, 2-206 weeks). Patients were primarily managed using Draf IIb frontal sinusotomies with 1 individual requiring a concomitant trephine. A Draf III procedure was performed in 1 patient. Average fracture defect (length vs width) was 13 × 4.5 mm, and average length involving the posterior table was 9.7 mm (1-30 mm). Skull base defects were covered with a septal flap and/or free tissue grafts. Although 1 individual required a revision frontal sinusotomy and follow-up was short in several patients, all sinuses remained patent on last clinical examination. Management of frontal sinus posterior table fractures using minimally invasive endoscopic techniques provides excellent outcomes in selected cases. Fractures of up to 30 mm in length were adequately managed in this series and indicate this approach can be a viable alternative in the treatment of these fractures.

  7. Is posterior delamination in arthroscopic rotator cuff repair hidden to the posterior viewing portal?

    PubMed

    Han, Yung; Shin, Jin-Hyup; Seok, Chang-Woo; Lee, Chang-Hyun; Kim, Seung-Ho

    2013-11-01

    The purposes of this study were (1) to examine whether posterior delamination is hidden to the most commonly used posterior viewing portal compared with differential rotator cuff portals and (2) to observe posterior delamination patterns so that a treatment-based classification system may be proposed. One-hundred thirty consecutive patients undergoing arthroscopic rotator cuff repair by 4 different surgeons were evaluated for the presence of posterior delamination viewable through the posterior, posterolateral, and lateral portals. Randomized arthroscopic pictures were viewed by 2 independent blinded observers, and the Fleiss κ was used to assess inter-reliability agreement. In addition, patterns of posterior delamination and surgical treatment were assessed. The incidence of posterior delamination was 88%. Only 11% of cases were visualized through the posterior portal, whereas 70% and 100% were visualized through the posterolateral and lateral portals, respectively. The Fleiss κ was 0.78 (95% confidence interval, 0.73 to 0.83), indicating substantial agreement. Three general patterns of posterior delamination with specific surgical repair strategies were identified and subclassified into 5 types: type A1, full-thickness tears with extensive posterior delamination separating the rotator cuff into 2 layers and sometimes with dissociation of the rotator cable; type A2, bursal-sided partial-thickness tears with posterior delamination; type B1, delamination with an L-shaped bursal layer tear and crescent-shaped articular layer tear; type B2, a partial-thickness articular-sided tear with extensive posterior delamination; and type C, extensive degeneration with multiple longitudinal bursal-sided tears. The incidence of posterior delamination is extremely high, and most of these lesions are missed if one is viewing from just the posterior portal. Differential rotator cuff portals are needed to appreciate and treat posterior delamination. Patterns of delamination can be

  8. Guanylin peptides regulate electrolyte and fluid transport in the Gulf toadfish (Opsanus beta) posterior intestine.

    PubMed

    Ruhr, Ilan M; Bodinier, Charlotte; Mager, Edward M; Esbaugh, Andrew J; Williams, Cameron; Takei, Yoshio; Grosell, Martin

    2014-11-01

    The physiological effects of guanylin (GN) and uroguanylin (UGN) on fluid and electrolyte transport in the teleost fish intestine have yet to be thoroughly investigated. In the present study, the effects of GN, UGN, and renoguanylin (RGN; a GN and UGN homolog) on short-circuit current (Isc) and the transport of Cl-, Na+, bicarbonate (HCO3-), and fluid in the Gulf toadfish (Opsanus beta) intestine were determined using Ussing chambers, pH-stat titration, and intestinal sac experiments. GN, UGN, and RGN reversed the Isc of the posterior intestine (absorptive-to-secretory), but not of the anterior intestine. RGN decreased baseline HCO3- secretion, but increased Cl- and fluid secretion in the posterior intestine. The secretory response of the posterior intestine coincides with the presence of basolateral NKCC1 and apical cystic fibrosis transmembrane conductance regulator (CFTR), the latter of which is lacking in the anterior intestine and is not permeable to HCO3- in the posterior intestine. However, the response to RGN by the posterior intestine is counterintuitive given the known role of the marine teleost intestine as a salt- and water-absorbing organ. These data demonstrate that marine teleosts possess a tissue-specific secretory response, apparently associated with seawater adaptation, the exact role of which remains to be determined. Copyright © 2014 the American Physiological Society.

  9. Computational fluid dynamics evaluation of posterior septectomy as a viable treatment option for large septal perforations.

    PubMed

    Otto, Bradley A; Li, Chengyu; Farag, Alexander A; Bush, Benjamin; Krebs, Jillian P; Hutcheson, Ryan D; Kim, Kanghyun; Deshpande, Bhakthi; Zhao, Kai

    2017-07-01

    Numerous surgical techniques exist to treat nasal septal perforation (NSP). The surgical closure of large NSPs (>2 cm) is still challenging. Posterior septectomy has been reported as a simple alternative to treat large NSP, yet its mechanisms for symptom relief are not clear, and if failed, its consequence cannot be easily reversed. Ten NSP patients were recruited: 5 underwent posterior septectomy and 5 underwent conventional flap or button repair. Computational fluid dynamics (CFD) simulated the nasal aerodynamics based on computed tomography (CT) scans. All patients had preoperative CT; however, only 4 had postoperative CT: 2 underwent posterior septectomy and the other 2 underwent flap repair. We examined surgical outcomes and the nasal airflow features among the 2 treatment options. Both groups of patients had good outcomes based on chart review. Patients undergoing septectomy had significantly larger perforation size (2.32 ± 0.87 vs 1.21 ± 0.60 cm), higher flow rate across the perforation (47.8 ± 28.6 vs 18.3 ± 12.2 mL/second), and higher wall shear stress (WSS) along the posterior perforation margin (1.39 ± 0.52 vs 1.15 ± 0.58 Pa). The posterior WSS significantly correlated with crossover flow velocity (r = 0.77, p = 0.009) and was reduced by almost 67% postseptectomy, and by 29% postrepair. This is the first CFD analysis on an NSP patient cohort. NSP resulted in flow disturbance and increased WSS that potentially led to symptomatology. The removal of high stress points along the posterior margin may explain why posterior septectomy can be an effective treatment option. Aerodynamic abnormalities, in addition to perforation size and location, could serve as basis for future treatment decisions. © 2017 ARS-AAOA, LLC.

  10. 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.

  11. Posterior cruciate ligament removal contributes to abnormal knee motion during posterior stabilized total knee arthroplasty.

    PubMed

    Cromie, Melinda J; Siston, Robert A; Giori, Nicholas J; Delp, Scott L

    2008-11-01

    Abnormal anterior translation of the femur on the tibia has been observed in mid flexion (20-60 degrees ) following posterior stabilized total knee arthroplasty. The underlying biomechanical causes of this abnormal motion remain unknown. The purpose of this study was to isolate the effects of posterior cruciate ligament removal on knee motion after total knee arthroplasty. We posed two questions: Does removing the posterior cruciate ligament introduce abnormal anterior femoral translation? Does implanting a posterior stabilized prosthesis change the kinematics from the cruciate deficient case? Using a navigation system, we measured passive knee kinematics of ten male osteoarthritic patients during surgery after initial exposure, after removing the anterior cruciate ligament, after removing the posterior cruciate ligament, and after implanting the prosthesis. Passively flexing and extending the knee, we calculated anterior femoral translation and the flexion angle at which femoral rollback began. Removing the posterior cruciate ligament doubled anterior translation (from 5.1 +/- 4.3 mm to 10.4 +/- 5.1 mm) and increased the flexion angle at which femoral rollback began (from 31.2 +/- 9.6 degrees to 49.3 +/- 7.3 degrees). Implanting the prosthesis increased the amount of anterior translation (to 16.1 +/- 4.4 mm), and did not change the flexion angle at which femoral rollback began. Abnormal anterior translation was observed in low and mid flexion (0-60 degrees) after removing the posterior cruciate ligament, and normal motion was not restored by the posterior stabilized prosthesis.

  12. Long-term discission rate after placing posterior chamber lenses with the convex surface posterior.

    PubMed

    Downing, J E

    1986-11-01

    The incidence of secondary capsulotomy was studied in a group of 757 posterior chamber intraocular lenses placed with the convex surface posterior within the capsular bag. Minimum follow-up was 12 months and ranged up to 61 months, with a mean of 33 months. In the first year, only 2.9% of cases required discission, but this rose to 15.7% at five years. The need for capsulotomy with angled-haptic lenses was 7.9% at three years; it was 15.0% with uniplanar lenses (P = .04). This difference appeared to be due to better apposition of the optic to the posterior capsule in the angled lenses, creating a more effective barrier to epithelial pearl migration. Capsulotomy carries significant risks and lens designs that minimize the long-term need for capsulotomy should be sought. Convex posterior lenses with angled haptics have a low incidence of posterior capsule opacification.

  13. Posterior scleritis: clinical profile and imaging characteristics.

    PubMed

    Biswas, J; Mittal, S; Ganesh, S K; Shetty, N S; Gopal, L

    1998-12-01

    Posterior scleritis is relatively uncommon and is often misdiagnosed due to its protean manifestations. We report eight cases of posterior scleritis to analyse the clinical profile, ultrasonographic and computed tomography (CT) scan features of this rare disorder. Fundus findings included serous retinal detachment, choroidal folds, retinal folds, subretinal mass, choroidal detachment, disc edema, and macular edema. There was associated anterior scleritis and anterior uveitis in the majority of the cases. In all cases ultrasound with or without CT scan confirmed the clinical diagnosis. All patients responded to systemic steroids except one who required immunosuppressive therapy. This paper describes the clinical profile of a series of posterior scleritis cases highlighting varied clinical presentation, and the role of ultrasound and CT scan findings in the diagnosis.

  14. Fundus autofluorescence imaging in posterior uveitis.

    PubMed

    Durrani, Khayyam; Foster, C Stephen

    2012-01-01

    Although the phenomenon of fundus autofluorescence has been known for decades, it has only recently been recognized as a measure of retinal pigment epithelial function and health. Characteristic fundus autofluorescence patterns have been described in eyes affected by inflammation of the posterior segment, and these patterns have provided insights into the pathogenesis of posterior uveitis entities. In addition, preliminary data indicate that fundus autofluorescence characteristics may serve as markers of disease activity, allow prediction of visual prognosis, and may help determine the adequacy of therapy. We provide an overview of the current state of fundus autofluorescence imaging technology and review our current knowledge of fundus autoflourescence findings and their clinical use in the posterior uveitis entities.

  15. Tubal Ligation Reversal

    MedlinePlus

    ... seal off the fallopian tubes, such as the Essure or Adiana systems, generally aren't reversible. In ... electrocautery). Some types of sterilization, such as the Essure system, are not considered reversible. Even if tubal ...

  16. A technique of anterior screw removal through a posterior costotransversectomy approach for posterior-based osteotomies.

    PubMed

    Lewis, Stephen J; David, Kenny; Singer, Syndie; Bacon, Sarah A; Kopka, Michaela; Gray, Randolph; Magana, Sofia

    2010-05-15

    Case report. To describe a novel technique to remove anterior instrumentation from a posterior approach while performing posterior-based osteotomies for spinal deformities. Posterior-based osteotomies such as pedicle subtraction osteotomies (PSOs) and vertebral column resections are performed to restore sagittal alignment. The removal of previously placed anterior implants at the desired osteotomy level can often be challenging. We propose a technique for the removal of anterior instrumentation through a posterior approach to facilitate osteotomy closure and deformity correction, while avoiding the need for an anterior incision. A 34-year-old woman presented with a residual deformity after several anterior and posterior procedures. The residual coronal Cobb angle measured 60 degrees between T7 and L2, with a 46 degrees thoracolumbar kyphosis between T10 and L2. The screw head at the desired osteotomy level was in close proximity to the liver after the previous right-sided thoracoabdominal approach. Therefore, the T11 anterior screw was accessed through a posterior costotransversectomy approach and disconnected from the rod proximally and distally with a high-speed side-cutting burr. A portion of the right lateral vertebral body of T11 was removed to expose the neck of the screw, which was separated from the shaft with the same burr. A PSO was performed at T11 and the remaining screw shank was removed with the posterior-based osteotomy. No major complications were encountered during the procedure. The anterior screw at T11 was removed from posteriorly, and the PSO was completed successfully. Postoperative recovery was without incident, and the patient was very satisfied with her results. This technique describes a novel, safe, and effective method to deal with anterior instrumentation from the posterior approach while performing posterior-based osteotomies for rigid spinal deformities.

  17. A retrospective study of posterior malleolus fractures.

    PubMed

    Xu, Hai-lin; Li, Xuan; Zhang, Dian-ying; Fu, Zhong-guo; Wang, Tian-bing; Zhang, Pei-xun; Jiang, Bao-guo; Shen, Hui-liang; Wang, Gang; Wang, Guang-lin; Wu, Xin-bao

    2012-09-01

    In this retrospective study, we evaluated the treatment effect of ankle joint fracture surgery involving the posterior malleolus, and discuss relevant factors influencing the occurrence of traumatic arthritis of the ankle joint. A total of 102 cases of ankle joint fractures involving the posterior malleolus in five large-scale skeletal trauma centres in China, from January 2000 to July 2009, were retrospectively analysed in terms of surgical treatment and complete follow-up. Ankle joint mobility, posterior malleolus fragment size, articular surface evenness, Ankle-Hindfoot Scale of the American Orthopedic Foot and Ankle Society (AOFAS) score, and imaging scale score for arthritis were recorded. The degree of fracture pain during rest, active movement, and weight-bearing walking, and satisfaction with treatment were evaluated using a visual analogue scale (VAS). The average AOFAS score was 95.9, excellence rate was 92.2 %, and average VAS scores for degree of fracture pain during rest, active movement, and weight-bearing walking were 0.15, 0.31, and 0.68, respectively. Thirty-six cases showed arthritic manifestations. Ankle joint mobility along all directions on the injured side was lower than that on the unaffected side. There was no obvious difference in treatment effect between the fixed and unfixed posterior malleolus fragment groups for all and for fragment size of < 25 %; between fixing the posterior malleolus fragment from front to back or from back to front; or between elderly patients (≥ 60 years old) and young patients (< 60 years old). There was a distinct difference in the treatment effect between articular surface evenness and unevenness for all and for fragment size of ≥ 25 %. For all 102 cases of ankle joint fracture involving the posterior malleolus, the treatment effect was satisfactory. Restoration of an even articular surface, especially when fragment size ≥ 25 %, should be attempted during treatment.

  18. 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. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Vasectomy and its reversal.

    PubMed

    Belker, A M

    1985-12-01

    Techniques, results, complications, and medicolegal aspects of vasectomy are discussed in this article. Emphasis is placed on techniques that prevent spontaneous recanalization of the ends of the vas deferens after vasectomy. Factors that affect the reversibility of vasectomy are discussed. New microsurgical techniques of vasectomy reversal are described, and results of these new techniques are compared with results of nonmicrosurgical techniques of vasectomy reversal. Indications for bypass vasoepididymostomy during vasectomy reversal procedures, as well as techniques for performing vasoepididymostomy, are discussed.

  20. Posterior cortical atrophy: a brief review.

    PubMed

    Kirshner, Howard S; Lavin, Patrick J M

    2006-11-01

    Posterior cortical atrophy is a striking clinical syndrome in which a dementing illness begins with visual symptoms. Initially, the problem may seem to be loss of elementary vision, but over time the patient develops features of visual agnosia, topographical difficulty, optic ataxia, simultanagnosia, ocular apraxia (Balint's syndrome), alexia, acalculia, right-left confusion, and agraphia (Gerstmann's syndrome), and later a more generalized dementia. Occasional patients have visual hallucinations and signs of Parkinson's disease or Lewy body dementia. A number of different neuropathologic disorders are associated with posterior cortical atrophy.

  1. 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…

  2. 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.

  3. Fuchs's heterochromic cyclitis and posterior capsulotomy.

    PubMed Central

    Roussel, T J; Coster, D J

    1985-01-01

    We report a case of intractable glaucoma following an uncomplicated secondary posterior capsulotomy in a 48-year-old male with Fuchs's heterochromic cyclitis. The patient had been free of inflammation and glaucoma since cataract extraction 27 years previously. We also report the results of phenotypic analysis of lymphocytes removed from the anterior chamber. Images PMID:3859323

  4. 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)

  5. Posterior Predictive Model Checking in Bayesian Networks

    ERIC Educational Resources Information Center

    Crawford, Aaron

    2014-01-01

    This simulation study compared the utility of various discrepancy measures within a posterior predictive model checking (PPMC) framework for detecting different types of data-model misfit in multidimensional Bayesian network (BN) models. The investigated conditions were motivated by an applied research program utilizing an operational complex…

  6. Posterior Predictive Model Checking in Bayesian Networks

    ERIC Educational Resources Information Center

    Crawford, Aaron

    2014-01-01

    This simulation study compared the utility of various discrepancy measures within a posterior predictive model checking (PPMC) framework for detecting different types of data-model misfit in multidimensional Bayesian network (BN) models. The investigated conditions were motivated by an applied research program utilizing an operational complex…

  7. 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)

  8. 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. Copyright © 2013 Elsevier Inc. All rights reserved.

  9. Treatment rationale of fractured posterior teeth.

    PubMed

    Silvestri, A R; Singh, I

    1978-11-01

    The four types of fractures most frequently encountered in posterior teeth--obliquely directed complete fractures, vertically directed complete fractures, obliquely directed incomplete fractures, and vertically directed incomplete fractures--have been described. A detailed treatment approach for each type has been presented.

  10. Posterior cingulate epilepsy: clinical and neurophysiological analysis.

    PubMed

    Enatsu, Rei; Bulacio, Juan; Nair, Dileep R; Bingaman, William; Najm, Imad; Gonzalez-Martinez, Jorge

    2014-01-01

    Posterior cingulate epilepsy (PCE) is misleading because the seizure onset is located in an anatomically deep and semiologically silent area. This type of epilepsy is rare and has not been well described yet. Knowledge of the characteristics of PCE is important for the interpretation of presurgical evaluation and better surgical strategy. The purpose of this study was to better characterise the clinical and neurophysiological features of PCE. This retrospective analysis included seven intractable PCE patients. Six patients had postcingulate ictal onset identified by stereotactic EEG (SEEG) evaluations. One patient had a postcingulate tumour. We analysed clinical semiology, the scalp EEG/SEEG findings and cortico-cortical evoked potential (CCEP). The classifications of scalp EEG were various, including non-localisible, lateralised to the seizure onset side, regional parieto-occipital, regional frontocentral and regional temporal. Three of seven patients showed motor manifestations, including bilateral asymmetric tonic seizures and hypermotor seizures. In these patients, ictal activities spread to frontal (lateral premotor area, orbitofrontal cortex, supplementary motor area, anteior cingulate gyrus) and parietal (precuneus, posterior cingulate gyrus, inferior parietal lobule (IPL), postcentral gyrus) areas. Four patients showed dialeptic seizures or automotor seizures, with seizure spread to medial temporal or IPL areas. CCEP was performed in four patients, suggesting electrophysiological connections from the posterior cingulate gyrus to parietal, temporal, mesial occipital and mesial frontal areas. This study revealed that the network from the posterior cingulate gyrus and the semiology of PCE (motor manifestation vs dialeptic/automotor seizure) varies depending upon the seizure spread patterns.

  11. Posterior dislocation of the shoulder in athletes.

    PubMed

    Samilson, R L; Prieto, V

    1983-07-01

    Although posterior dislocation of the shoulder is a rare injury in athletes, failure to recognize and properly manage acute dislocation may have serious consequences. The article discusses the incidence, mechanism of injury, classification, pathologic findings, clinical and radiologic diagnosis, and management.

  12. Complicated posterior capsulorhexis: aetiology, management, and outcome

    PubMed Central

    Van Cauwenberge, F.; Rakic, J.; Galand, A.

    1997-01-01

    BACKGROUND—A 1 year retrospective analysis of 650 patients, who underwent a posterior capsulorhexis on their intact capsules, was performed to examine the incidence of complications, their aetiologies, and the outcome.
METHODS—Data were analysed on 32 patients with complicated capsulorhexis for type of surgery, preoperative and postoperative factors, and relative risk factors for vitreous issue.
RESULTS—There were six patients with vitreous loss. The posterior capsulorhexis was uncontrolled in 14 cases and difficult to perform in 12 cases. Implantation into the capsular bag was possible in all cases. Systemic vascular hazard and old age (over 80 years) were found to be statistically significant risk factors for vitreous loss (p=0.002 and p=0.03 respectively). The mean follow up was 13.5 months (range 4-25 months). One patient developed a retinal detachment and two had a transient clinical cystoid macular oedema. Visual acuity of ≥ 20/40 was obtained in 93% of the patients.
CONCLUSION—Loss of control of the posterior capsulorhexis has a low incidence but can lead to serious problems during surgery. A good knowledge of the technique is necessary to complete the procedure with a posterior capsulorhexis of the optimum size without vitreous loss.

 PMID:9135382

  13. BAER suppression during posterior fossa dural opening

    PubMed Central

    Shields, Christopher B.; Shields, Lisa B. E.; Jiang, Yi Dan; Yao, Tom; Zhang, Yi Ping; Sun, David A.

    2015-01-01

    Background: Intraoperative monitoring with brainstem auditory evoked responses (BAER) provides an early warning signal of potential neurological injury and may avert tissue damage to the auditory pathway or brainstem. Unexplained loss of the BAER signal in the operating room may present a dilemma to the neurosurgeon. Methods: This paper documents two patients who displayed a unique mechanism of suppression of the BAER apparent within minutes following dural opening for resection of a posterior fossa meningioma. Results: In two patients with anterior cerebellopontine angle and clival meningiomas, there was a significant deterioration of the BAER soon after durotomy but prior to cerebellar retraction and tumor removal. Intracranial structures in the posterior fossa lying between the tumor and dural opening were shifted posteriorly after durotomy. Conclusion: We hypothesized that the cochlear nerve and vessels entering the acoustic meatus were compressed or stretched when subjected to tissue shift. This movement caused cochlear nerve dysfunction that resulted in BAER suppression. BAER was partially restored after the tumor was decompressed, dura repaired, and bone replaced. BAER was not suppressed following durotomy for removal of a meningioma lying posterior to the cochlear complex. Insight into the mechanisms of durotomy-induced BAER inhibition would allay the neurosurgeon's anxiety during the operation. PMID:25883849

  14. The eyeglass reversal.

    PubMed

    Oh, Songjoo

    2011-07-01

    Some figures, such as the Necker cube, are spontaneously reversible between alternative percepts. Before learning those skilled reversals, how do people achieve reversals for the very first time? It has been known that, in the case of a first reversal, people can be expected to see the reversal when given specific information about how the figures are ambiguous. This point was confirmed by using drawing versions of reversible figures. To demonstrate how intention plays a role in the initial reversal of a real object, a pair of regular eyeglasses, reversible in perspective, were presented to naïve observers in monocular vision. When the eyeglasses were viewed inwardly and the observers were given information that the eyeglasses could be ambiguous, they were able to easily see the reversal. When the eyeglasses were viewed outwardly, observers saw it only after they had been informed of exactly what the two alternative percepts were.Interestingly, many observers often mistakenly saw the inwardly viewed eyeglasses as placed outwardly from the beginning of the observation, while they saw the outwardly viewed eyeglasses correctly. Taking these results together, for the first reversal of a real object, the specificity of intention varies with the ambiguity of the object.

  15. Reversible obstructive hydrocephalus from hypertensive encephalopathy.

    PubMed

    Kumar, Abhay; Keyrouz, Salah G; Willie, Jon T; Dhar, Rajat

    2012-06-01

    Diffuse edema involving the posterior fossa may be seen with hypertensive encephalopathy and has rarely been reported to cause hydrocephalus. We present three such cases and review the literature to better delineate this uniquely reversible syndrome. Case reports and review of literature. Three patients with hypertensive encephalopathy presented to our institutions with clinical and radiographic features of obstructive hydrocephalus associated with brainstem and cerebellar edema. This required transient external drainage of cerebrospinal fluid (CSF) in two of the three patients. However, with recognition of this unusual syndrome and aggressive management of elevated blood pressure, both edema and hydrocephalus resolved. All patients made complete recoveries and did not require permanent CSF shunting. A review of the literature yielded 15 additional case reports describing reversible obstructive hydrocephalus related to hypertensive encephalopathy. All had mean arterial pressures above 130 mmHg and presented primarily with altered mental status. While half required ventriculostomy, only one required shunting. Excluding a patient who died from sepsis, all recovered neurologically once blood pressure was controlled. It is imperative to recognize such cases where hypertension causes edema within the posterior fossa resulting in secondary hydrocephalus. Focusing management on lowering blood pressure avoids unnecessary or prolonged CSF diversion.

  16. [Condition of the posterior capsule in pseudophakia in children].

    PubMed

    Koraszewska-Matuszewska, B; Samochowiec-Donocik, E; Pieczara, E

    1995-01-01

    Evaluation of the posterior capsule transparency in children after congenital cataract surgery with posterior intraocular lens implantation. Examination comprised 41 eyes of 29 patients with posterior IOLS, aged 5-17 years (mean 10.3). In all cases, posterior capsule was unimpaired during surgery. During follow-up, (mean 27 months), 36.6% the eyes showed posterior capsule opacity of various degree. Neodymium YAG laser capsulotomy was performed in 13 cases and instrumental capsulotomy in 2. Opacity of the posterior capsule caused a decrease of visual acuity below 0.4. It improved after capsulotomy in all cases. No serious complications were observed.

  17. 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. Copyright © 2011 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  18. 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

  19. Differential effects of dopamine D2 and GABAA receptor antagonists on dopamine neurons between the anterior and posterior ventral tegmental area of female Wistar rats

    PubMed Central

    Ding, Zheng-Ming; Liu, Wen; Engleman, Eric A.; Rodd, Zachary A.; McBride, William J.

    2010-01-01

    Previous findings indicated differences in neuronal circuitries mediating drug reinforcement between the anterior and posterior ventral tegmental area (VTA). The objective of the present study was to examine the effects of the dopamine D2 antagonist sulpiride and the GABAA antagonist picrotoxin administered in the anterior and posterior VTA on the activity of mesoaccumbal dopamine neurons in female Wistar rats. Sulpiride and picrotoxin were administered in the anterior and posterior VTA. Extracellular dopamine levels were measured in sub-regions of the VTA and nucleus accumbens (ACB). Reverse-microdialysis of sulpiride (100 µM) into the posterior VTA increased extracellular dopamine levels locally (80% above baseline) and in the ACB shell and core (70% above baseline), whereas reverse-microdialysis into the anterior VTA produced a much smaller effect locally (30% above baseline) and in the ACB shell and core. In contrast, microinjection of picrotoxin (80 and 160 µM) into the anterior, but not posterior VTA, increased dopamine release in the ACB shell. The results suggest that dopamine neurons in the posterior VTA, compared to the anterior VTA, may be under greater D2 receptor-mediated tonic inhibition, whereas dopamine neurons in the anterior VTA, compared to the posterior VTA, may be under greater GABAA receptor-mediated tonic inhibition. PMID:19480073

  20. Posterior Cruciate Ligament Removal Contributes to Abnormal Knee Motion during Posterior Stabilized Total Knee Arthroplasty

    PubMed Central

    Cromie, Melinda J.; Siston, Robert A.; Giori, Nicholas J.; Delp, Scott L.

    2017-01-01

    Abnormal anterior translation of the femur on the tibia has been observed in mid flexion (20–60°) following posterior stabilized total knee arthroplasty. The underlying biomechanical causes of this abnormal motion remain unknown. The purpose of this study was to isolate the effects of posterior cruciate ligament removal on knee motion after total knee arthroplasty. We posed two questions: Does removing the posterior cruciate ligament introduce abnormal anterior femoral translation? Does implanting a posterior stabilized prosthesis change the kinematics from the cruciate deficient case? Using a navigation system, we measured passive knee kinematics of ten male osteoarthritic patients during surgery after initial exposure, after removing the anterior cruciate ligament, after removing the posterior cruciate ligament, and after implanting the prosthesis. Passively flexing and extending the knee, we calculated anterior femoral translation and the flexion angle at which femoral rollback began. Removing the posterior cruciate ligament doubled anterior translation (from 5.1±4.3 mm to 10.4±5.1 mm) and increased the flexion angle at which femoral rollback began (from 31.2±9.6° to 49.3±7.3°). Implanting the prosthesis increased the amount of anterior translation (to 16.1±4.4 mm), and did not change the flexion angle at which femoral rollback began. Abnormal anterior translation was observed in low and mid flexion (0–60°) after removing the posterior cruciate ligament, and normal motion was not restored by the posterior stabilized prosthesis. PMID:18464260

  1. 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

  2. Reversible logic for supercomputing.

    SciTech Connect

    DeBenedictis, Erik P.

    2005-05-01

    This paper is about making reversible logic a reality for supercomputing. Reversible logic offers a way to exceed certain basic limits on the performance of computers, yet a powerful case will have to be made to justify its substantial development expense. This paper explores the limits of current, irreversible logic for supercomputers, thus forming a threshold above which reversible logic is the only solution. Problems above this threshold are discussed, with the science and mitigation of global warming being discussed in detail. To further develop the idea of using reversible logic in supercomputing, a design for a 1 Zettaflops supercomputer as required for addressing global climate warming is presented. However, to create such a design requires deviations from the mainstream of both the software for climate simulation and research directions of reversible logic. These deviations provide direction on how to make reversible logic practical.

  3. Perspective: reverse evolution.

    PubMed

    Teotónio, H; Rose, M R

    2001-04-01

    For some time, the reversibility of evolution was primarily discussed in terms of comparative patterns. Only recently has this problem been studied using experimental evolution over shorter evolutionary time frames. This has raised questions of definition, experimental procedure, and the hypotheses being tested. Experimental evolution has provided evidence for multiple population genetic mechanisms in reverse evolution, including pleiotropy and mutation accumulation. It has also pointed to genetic factors that might prevent reverse evolution, such as a lack of genetic variability, epistasis, and differential genotype-by-environment interactions. The main focus of this perspective is on laboratory studies and their relevance to the genetics of reverse evolution. We discuss reverse evolution experiments with Drosophila, bacterial, and viral populations. Field studies of the reverse evolution of melanism in the peppered moth are also reviewed.

  4. HIV-1 Reverse Transcription

    PubMed Central

    Hu, Wei-Shau; Hughes, Stephen H.

    2012-01-01

    Reverse transcription and integration are the defining features of the Retroviridae; the common name “retrovirus” derives from the fact that these viruses use a virally encoded enzyme, reverse transcriptase (RT), to convert their RNA genomes into DNA. Reverse transcription is an essential step in retroviral replication. This article presents an overview of reverse transcription, briefly describes the structure and function of RT, provides an introduction to some of the cellular and viral factors that can affect reverse transcription, and discusses fidelity and recombination, two processes in which reverse transcription plays an important role. In keeping with the theme of the collection, the emphasis is on HIV-1 and HIV-1 RT. PMID:23028129

  5. Arterial anatomy of the tibialis posterior tendon.

    PubMed

    Manske, Mary Claire; McKeon, Kathleen E; Johnson, Jeffrey E; McCormick, Jeremy J; Klein, Sandra E

    2015-04-01

    Tibialis posterior tendon dysfunction is a common disorder leading to pain, deformity, and disability, although its pathogenesis is unclear. A vascular etiology has been proposed, but there is controversy regarding the existence of a hypovascular region that may render the tendon vulnerable. The purpose of this study was to provide a description of the arterial anatomy supplying the tibialis posterior tendon. Sixty adult cadaveric lower extremities were obtained from a university-affiliated body donation program. Thirty specimens obtained within 72 hours of death were used for microscopic analysis. Thirty specimens were previously frozen and used for macroscopic analysis. The tibialis anterior, tibialis posterior, and peroneal arteries were injected with India Ink and Ward's Blue Latex. The specimens used for macroscopic analysis were debrided with sodium hypochlorite to expose the extratendinous anatomy. For the microscopic analysis, the tendon was cleared using a modified Spälteholz technique to expose the intratendinous vascular anatomy. Macroscopically, an average of 2.5 ± 0.7 vessels entered the tendon proximal to the navicular insertion. In all, 28/30 (93.3%) specimens had a vessel entering 4.1 ± 0.6 cm proximal to the medial malleolus and 24/30 (80.0%) specimens had a vessel entering 1.7 ± 0.9 cm distal to the medial malleolus. Microscopically, an average of 1.9 ± 0.3 vessels entered each tendon proximal to the navicular insertion. In total, 27/30 (90%) specimens had a vessel entering the tendon 4.8 ± 0.8 cm proximal to the medial malleolus and 30/30 (100%) specimens had a vessel entering the tendon 1.9 ± 0.8 cm distal to the medial malleolus. In all specimens, a hypovascular region was observed, starting 2.2 ± 0.8 cm proximal to the medial malleolus and ending 0.6 ± 0.6 cm proximal to the medial malleolus with an average length of 1.5 ± 1.0 cm. The insertion of the tendon was well vascularized both on microscopic and macroscopic specimens. The

  6. 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

  7. Posterior Arthroscopic Subtalar Arthrodesis: Clinical and Radiologic Review of 19 Cases.

    PubMed

    Martín Oliva, Xavier; Falcão, Pedro; Fernandes Cerqueira, Raul; Rodrigues-Pinto, Ricardo

    Arthroscopic subtalar arthrodesis has recently gained popularity in the treatment of primary subtalar or post-traumatic arthritis, coalition, or inflammatory diseases with subtalar arthritis. The present study reports the clinical and radiologic results of 19 patients (19 feet) who underwent posterior arthroscopic subtalar arthrodesis using 2 posterior portals. A total of 19 posterior arthroscopic subtalar arthrodeses (minimum follow-up of 24 months) performed without a bone graft and with 2 parallel screws were prospectively evaluated. The fusion rate was 94% (mean time to fusion 9.8 weeks). Modified American Orthopaedic Foot and Ankle Society ankle-hindfoot scale score (maximum 94 points) improved significantly from 43 to 80 points and the visual analog scale for pain score improved from 7.6 to 1.2. The 12-item short-form physical and mental scores at the last follow-up point were 52.5 and 56.4, respectively. One (5.3%) patient underwent open repeat fusion for nonunion, 2 (10.5%) patients required a second procedure for implant removal, and 1 (5.3%) experienced reversible neuropraxia. In conclusion, posterior arthroscopic subtalar arthrodesis is a safe technique with a good union rate and a small number of complications in patients with no or very little hindfoot deformity. Copyright © 2017 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  8. Acute traumatic posterior elbow dislocation in children.

    PubMed

    Lieber, Justus; Zundel, Sabine M; Luithle, Tobias; Fuchs, Jörg; Kirschner, Hans-Joachim

    2012-09-01

    Traumatic posterior dislocation of the elbow is often associated with significant morbidity and incomplete recovery. The aim of this study was to retrospectively analyse the outcome of 33 children (median age 10.8 years). Patients underwent reduction and assessment of stability under general anaesthesia. Pure dislocations (n=10) were immobilized, whereas unstable fractures (n=23) were stabilized. Refixation of ligaments was performed if stability was not achieved by fracture stabilization alone. Immobilization was continued for 26 (pure dislocations) or 35 days (associated injuries), respectively. Results were excellent (n=9) or good (n=1) after pure dislocation. Results were excellent (n=15), good (n=7) or poor (n=1) in children with associated injuries. Accurate diagnosis, concentric stable reduction of the elbow as well as stable osteosynthesis of displaced fractures are associated with good results in children with acute posterior elbow dislocations.

  9. Mature posterior fossa teratoma mimicking dermoid cyst.

    PubMed

    Bohara, Manoj; Yonezawa, Hajime; Karki, Prasanna; Bakhtiar, Yuriz; Hirano, Hirofumi; Kitazono, Ikumi; Matsuyama, Nozomu; Arita, Kazunori

    2013-10-01

    We describe a very rare case of mature posterior fossa teratoma in an adult who presented with clinico-radiological findings consistent with a dermoid cyst. A computed tomography scan showed a hypodense mass in the cistern magna with calcification and a sinus tract in the occipital bone. Magnetic resonance imaging revealed a hypo- to hyperintense mass without contrast enhancement. The intraoperative picture showed a dermal sinus and a cyst containing lipid, keratin and hair. Histopathological examination showed a tumor with components of all the three germ layers; thereby, a diagnosis of mature teratoma was made. The histopathological differentiation between teratoma and dermoid cyst is very valuable for ruling out the presence of immature/malignant or germinomatous components that would require further adjuvant therapies. Thus, we here present a rare case of posterior fossa teratoma mimicking dermoid cyst and emphasize the importance of histopathological differentiation between these entities.

  10. [Manual rotation of occiput posterior presentation].

    PubMed

    Le Ray, C; Goffinet, F

    2011-10-01

    Delivery in occiput posterior position is associated with a higher risk of cesarean section, operative vaginal delivery and severe perineal tears. We report the technic of manual rotation described by Tarnier and Chantreuil and used daily in our maternity center. Only five studies were published on this topic; all of them demonstrate that manual rotation decreases the risk of cesarean section. Moreover, it could decrease the risk of prolonged second stage, chorioamnionitis and third and fourth degree tears in comparison with expectant management. However, manual rotation is associated with a two-fold higher risk of cervical and vaginal lacerations. Manual rotation performed with an adequate technic is an efficient and safe manœuvre to avoid complications associated with occiput posterior vaginal delivery.

  11. Visual Dysfunction in Posterior Cortical Atrophy

    PubMed Central

    da Silva, Mari N. Maia; Millington, Rebecca S.; Bridge, Holly; James-Galton, Merle; Plant, Gordon T.

    2017-01-01

    Posterior cortical atrophy (PCA) is a syndromic diagnosis. It is characterized by progressive impairment of higher (cortical) visual function with imaging evidence of degeneration affecting the occipital, parietal, and posterior temporal lobes bilaterally. Most cases will prove to have Alzheimer pathology. The aim of this review is to summarize the development of the concept of this disorder since it was first introduced. A critical discussion of the evolving diagnostic criteria is presented and the differential diagnosis with regard to the underlying pathology is reviewed. Emphasis is given to the visual dysfunction that defines the disorder, and the classical deficits, such as simultanagnosia and visual agnosia, as well as the more recently recognized visual field defects, are reviewed, along with the evidence on their neural correlates. The latest developments on the imaging of PCA are summarized, with special attention to its role on the differential diagnosis with related conditions. PMID:28861031

  12. Posterior tibial nerve lesions in ankle arthroscopy.

    PubMed

    Cugat, Ramon; Ares, Oscar; Cuscó, Xavier; Garcia, Montserrat; Samitier, Gonzalo; Seijas, Roberto

    2008-05-01

    Ankle arthroscopy provides a minimally invasive approach to the diagnosis and treatment of certain ankle disorders. Neurological complications resulting from ankle arthroscopy have been well documented in orthopaedic and podiatric literature. Owing to the superficial location of the ankle joint and the abundance of overlying periarticular neurovascular structures, complications reported in ankle arthroscopy are greater than those reported for other joints. In particular, all reported neurovascular injuries following ankle arthroscopy have been the direct result of distractor pin or portal placement. The standard posteromedial portal has recognized risks because of the proximity of the posterior neurovascular structures. There can be considerable variability in the course of these portals and their proximity to the neurovascular structures. We found one report of intra-articular damage to the posterior tibial nerve as a result of ankle arthroscopy in the English-language literature and we report this paper as a second case described in the literature.

  13. Reverse Core Engine with Thrust Reverser

    NASA Technical Reports Server (NTRS)

    Suciu, Gabriel L. (Inventor); Chandler, Jesse M. (Inventor)

    2017-01-01

    An engine system has a gas generator, a bi-fi wall surrounding at least a portion of the gas generator, a casing surrounding a fan, and the casing having first and second thrust reverser doors which in a deployed position abut each other and the bi-fi wall.

  14. Posterior approach to ventrally located spinal meningiomas

    PubMed Central

    Voulgaris, Spyridon; Mihos, Evaggelos; Karagiorgiadis, Dimitrios; Zigouris, Andreas; Fotakopoulos, George; Drosos, Dimitrios; Pahaturidis, Dimitrios

    2010-01-01

    For the resection of anteriorly located meningiomas, various approaches have been used. Posterior approach is less invasive and demanding; however, it has been associated with increased risk of spinal cord injury. We evaluated ten consecutive patients that underwent surgery for spinal meningiomas. All patients were preoperative assessed by neurological examination, computed tomography and magnetic resonance imaging. All tumors were ventrally located and removed via a posterior approach. Transcranial motor-evoked potentials (TcMEPs), somatosensory-evoked potential (SSEP) and free running electromyography (EMG) were monitored intraoperative. Postoperative all patients had regular follow-up examinations. There were four males and six females. The mean age was 68.2 years (range 39–82 years). In nine out of ten cases, the tumor was located in the thoracic spine. A case of a lumbar meningioma was recorded. The most common presenting symptom was motor and sensory deficits and unsteady gait, whereas no patient presented with paraplegia. All meningiomas were operated using a microsurgical technique via a posterior approach. During the operation, free running EMG monitoring prompted a surgical alert in case of irritation, whereas TcMEP and SSEP amplitudes remained unchanged. Histopathology revealed the presence of typical (World Health Organisation grade I) meningiomas. The mean Ki-67/MIB-1 index was 2.75% (range 0.5–7). None of our patients sustained a transient or permanent motor deficit. After a mean follow-up period of 26 months (range 56–16 months), no tumor recurrence and no instability were found. Posterior approach for anteriorly located meningiomas is a safe procedure with the use of intraoperative monitoring, less invasive and well-tolerated especially in older patients. Complete tumor excision can be performed with satisfactory results. PMID:20127494

  15. Material Properties of the Posterior Human Sclera☆

    PubMed Central

    Grytz, Rafael; Fazio, Massimo A.; Girard, Michael J.A.; Libertiaux, Vincent; Bruno, Luigi; Gardiner, Stuart; Girkin, Christopher A.; Downs, J. Crawford

    2013-01-01

    To characterize the material properties of posterior and peripapillary sclera from human donors, and to investigate the macro- and micro-scale strains as potential control mechanisms governing mechanical homeostasis. Posterior scleral shells from 9 human donors aged 57–90 years were subjected to IOP elevations from 5 to 45 mmHg and the resulting full-field displacements were recorded using laser speckle interferometry. Eye-specific finite element models were generated based on experimentally measured scleral shell surface geometry and thickness. Inverse numerical analyses were performed to identify material parameters for each eye by matching experimental deformation measurements to model predictions using a microstructure-based constitutive formulation that incorporates the crimp response and anisotropic architecture of scleral collagen fibrils. The material property fitting produced models that fit both the overall and local deformation responses of posterior scleral shells very well. The nonlinear stiffening of the sclera with increasing IOP was well reproduced by the uncrimping of scleral collagen fibrils, and a circumferentially-aligned ring of collagen fibrils around the scleral canal was predicted in all eyes. Macroscopic in-plane strains were significantly higher in peripapillary region then in the mid-periphery. In contrast, the meso- and micro-scale strains at the collagen network and collagen fibril level were not significantly different between regions. The elastic response of the posterior human sclera can be characterized by the anisotropic architecture and crimp response of scleral collagen fibrils. The similar collagen fibril strains in the peripapillary and mid-peripheral regions support the notion that the scleral collagen architecture including the circumpapillary ring of collagen fibrils evolved to establish optimal load bearing conditions at the collagen fibril level. PMID:23684352

  16. Progressive visual agnosia with posterior cortical atrophy.

    PubMed

    Mizuno, M; Sartori, G; Liccione, D; Battelli, L; Campo, R

    1996-05-01

    A patient of posterior cortical atrophy characterized by early signs of progressive visual agnosia documented by repeated neuropsychological tests, is reported. SPECT and MRI findings showed left unilateral parieto-occipital involvement in the earlier stage. A PET study executed eight months later showed bilateral parieto-occipital hypometabolism, but predominantly in the left hemisphere. This suggests that the degeneration may have developed asymmetrically, progressing from left unilateral to bilateral.

  17. Posterior quadrant epilepsy surgery: predictors of outcome.

    PubMed

    Davis, Kristin L; Murro, Anthony M; Park, Yong D; Lee, Gregory P; Cohen, Morris J; Smith, Joseph R

    2012-11-01

    To identify predictors of seizure recurrence following posterior quadrant epilepsy surgery. Between 1983 and 2008, 43 medically refractory epilepsy patients underwent posterior quadrant epilepsy surgery. Epilepsy surgery involved the occipital lobe in all cases; some cases also included resection of the adjacent parietal or temporal cortex. Using a logistic regression model, we evaluated the relationship between outcome (Engel class I-IV) and 5 outcome predictors: absence of a visual aura, a temporal lobe type aura, versive head movement unaccompanied by a visual aura, non-focal interictal scalp EEG, and surgical pathology other than low grade tumor or cortical dysplasia. We also determined the relative risk for significant post-operative cognitive decline of Wechsler intelligence test score among those receiving complete lobectomies compared to those receiving partial lobectomies. Overall, outcome was favorable at 1 year following surgery: 22 (51.2%) patients Engel class I, 10 (24%) patients Engel class II, 5 (12%) patients Engel class III, and 6 (14%) patients Engel class IV. The 3 best univariate predictors of seizure recurrence were versive head movement unaccompanied by visual aura, non-focal interictal scalp EEG, and pathology other than low grade tumor or cortical dysplasia. A multivariate predictor combining temporal lobe type aura, versive head movement unaccompanied by visual aura, non-focal interictal scalp EEG, and pathology other than low grade tumor or cortical dysplasia was optimum. Complete lobectomy significantly increased the risk of post-operative decline of Wechsler intelligence score. These findings indicate that posterior quadrant epilepsy surgery may provide sustained seizure control. A multivariate model combining temporal lobe type aura, versive head movement unaccompanied by a visual aura, non-focal interictal scalp EEG, and pathology other than low grade tumor or cortical dysplasia may contribute to predicting seizure recurrence following

  18. Iris fixation of posterior chamber intraocular lenses.

    PubMed

    Yazdani-Abyaneh, Alireza; Djalilian, Ali R; Fard, Masoud Aghsaei

    2016-12-01

    We introduce a technique for iris fixation of a posterior chamber intraocular lens (IOL) in which most of the procedure is done outside the eye. This minimizes intraocular manipulation, maximizes corneal endothelial preservation, and avoids the risk for IOL drop into the vitreous cavity intraoperatively. The IOL is fixated to the most peripheral part of the iris, resulting in a rounder pupil. Sutures are placed at exact positions on the haptics, resulting in a well-centered IOL.

  19. 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

  20. Endoscopic posterior interhemispheric complete corpus callosotomy.

    PubMed

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

    2016-12-01

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

  1. Posterior approach to ventrally located spinal meningiomas.

    PubMed

    Voulgaris, Spyridon; Alexiou, George A; Mihos, Evaggelos; Karagiorgiadis, Dimitrios; Zigouris, Andreas; Fotakopoulos, George; Drosos, Dimitrios; Pahaturidis, Dimitrios

    2010-07-01

    For the resection of anteriorly located meningiomas, various approaches have been used. Posterior approach is less invasive and demanding; however, it has been associated with increased risk of spinal cord injury. We evaluated ten consecutive patients that underwent surgery for spinal meningiomas. All patients were preoperative assessed by neurological examination, computed tomography and magnetic resonance imaging. All tumors were ventrally located and removed via a posterior approach. Transcranial motor-evoked potentials (TcMEPs), somatosensory-evoked potential (SSEP) and free running electromyography (EMG) were monitored intraoperative. Postoperative all patients had regular follow-up examinations. There were four males and six females. The mean age was 68.2 years (range 39-82 years). In nine out of ten cases, the tumor was located in the thoracic spine. A case of a lumbar meningioma was recorded. The most common presenting symptom was motor and sensory deficits and unsteady gait, whereas no patient presented with paraplegia. All meningiomas were operated using a microsurgical technique via a posterior approach. During the operation, free running EMG monitoring prompted a surgical alert in case of irritation, whereas TcMEP and SSEP amplitudes remained unchanged. Histopathology revealed the presence of typical (World Health Organisation grade I) meningiomas. The mean Ki-67/MIB-1 index was 2.75% (range 0.5-7). None of our patients sustained a transient or permanent motor deficit. After a mean follow-up period of 26 months (range 56-16 months), no tumor recurrence and no instability were found. Posterior approach for anteriorly located meningiomas is a safe procedure with the use of intraoperative monitoring, less invasive and well-tolerated especially in older patients. Complete tumor excision can be performed with satisfactory results.

  2. Posterior thalamic hemorrhage induces "pusher syndrome".

    PubMed

    Karnath, Hans-Otto; Johannsen, Leif; Broetz, Doris; Küker, Wilhelm

    2005-03-22

    Recent findings argue for a pathway in humans for sensing the orientation of gravity and controlling upright body posture, separate from the one for orientation perception of the visual world. Stroke patients with contraversive pushing were shown to experience their body as oriented upright when actually tilted about 20 degrees to the ipsilesional side, in spite of normal visual-vestibular functioning. A recent study suggested the involvement of posterolateral thalamus typically associated with the disorder. To evaluate the relationship between pushing behavior and thalamic function. Over a 3-year period the authors prospectively investigated 40 patients with left- or right-sided thalamic strokes. Twenty-eight percent showed contraversive pushing. The authors found a strong relationship between etiology, vascular territory, lesion size, and neurologic disorders associated with contraversive pushing. Pusher patients had larger lesions that typically were caused by hemorrhage (vs infarcts) located in the posterior thalamus (vs anterior thalamic lesions in those patients without pushing behavior). A paresis of the contralesional extremities was more frequent and more severe in pusher patients. Further, these patients showed more additional spatial neglect with right thalamic lesions, while they tended to be more aphasic with left thalamic lesions. Posterior thalamus seems to be fundamentally involved in our control of upright body posture. Higher pressure, swelling, and other secondary pathologic processes associated with posterior thalamic hemorrhage (vs thalamic infarction) may provoke contraversive pushing in combination with additional neurologic symptoms.

  3. Tacrolimus Ointment for Refractory Posterior Blepharitis.

    PubMed

    Sakassegawa-Naves, Fernando Eiji; Ricci, Helena Maria Moraes; Moscovici, Bernardo Kaplan; Miyamoto, Daniela Akemi; Chiacchio, Brenda Biagio; Holzchuh, Ricardo; Santo, Ruth Muyuki; Hida, Richard Yudi

    2017-09-18

    This prospective, randomized, double-blind interventional case series was designed to evaluate the short-term efficacy of 0.03% tacrolimus ointment as a new therapeutic approach for refractory cases of posterior blepharitis. Forty eyes (20 patients) with posterior blepharitis refractory to previous treatment were randomized. Eighteen eyes (9 patients) were treated with 0.03% tacrolimus ointment and 20 eyes (10 patients) with placebo ointment twice daily. Patients were evaluated with a questionnaire and slit-lamp examination 14 days and 28 days after treatment, and symptoms and signs of blepharitis were compared to those observed at baseline. We could observe statistical difference in the outcome measurements of meibomian gland secretion, conjunctival hyperemia, telangiectasia of inferior lid, Rose Bengal, and fluorescein scoring for the study group. As for the symptoms score, we observed statistical difference in the symptoms scoring for pruritus and dry eye sensation in the tacrolimus group. This study suggests that topical administration of 0.03% tacrolimus ointment can improve some symptoms and some ocular surface status in patients with refractory posterior blepharitis.

  4. Indocyanine green angiography in posterior uveitis.

    PubMed

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

    2013-04-01

    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.

  5. 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

  6. Posterior fossa syndrome—a narrative review

    PubMed Central

    Wahab, Salima S.; Hettige, Samantha; Mankad, Kshtij

    2016-01-01

    Posterior fossa syndrome (PFS), or cerebellar mutism syndrome (CMS), is a collection of neurological symptoms that occur following surgical resection of a posterior fossa tumour, and is characterised by either a reduction or an absence of speech. Some authors suggest that CM is only one symptom of the CMS complex that also includes ataxia, hypotonia and irritability as well as cranial nerve deficits, neurobehavioral changes and urinary retention or incontinence. It is seen almost exclusively in children. In 1985 Rekate et al. published the first work describing CM as a clinical entity, occurring as a consequence of bilateral cerebellar injury. Other associated symptoms include visual impairment, altered mood, impaired swallowing and significant gross and fine motor deficits. The effects of this can have a devastating impact on both the patient and their carers, posing a significant clinical challenge to neurorehabilitation services. The reported incidence was between 8% and 31% of children undergoing surgery for posterior fossa tumour. The underlying pathologies include vasospasm, oedema, and axonal/neuronal injury. Neuroimaging has contributed to a better understanding of the anatomical location of postoperative injury. There have been a number of suggestions for treatment interventions for PFS. However, apart from some individual reports, there have been no clinical trials indicating possible benefit. Occupational therapy, speech and language therapy, as well as neurocognitive support, contribute to the recovery of these patients. PMID:27942479

  7. 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.

  8. Prone and direct posterior approach for management of posterior column tibial plateau fractures.

    PubMed

    Lin, K-C; Tarng, Y-W; Lin, G-Y; Yang, S-W; Hsu, C-J; Renn, J-H

    2015-06-01

    The three-column fixation concept is becoming popular in orthopedic practice. Posterior column fracture is an uncommon type of tibial plateau fracture. The supine position for the surgical approach is familiar to most surgeons; however, it is difficult to achieve good reduction and fixation in posterior column fracture. The prone position and direct posterior approach can achieve proper reduction and fixation for posterior column tibial plateau fracture, yielding good functional outcome. Between January 2010 and January 2012, 184 tibial plateau fractures were diagnosed and operated on in our institution. Sixteen posterior column tibial plateau fractures (10 male and 6 female patients, with a mean age of 41.5 ± 14.3 years) were diagnosed by preoperative plain films and CT scans. Ten patients presented with fracture-dislocation of the knee joint. A direct posterior approach in prone position was used to reduce the tibial condyle and fix it with an anti-glide buttress plate. Radiographic evaluation included reduction quality and bone union. Functional evaluation included Lysholm score and Tegner activity score. All fractures healed within 6 months, without secondary displacement. Ten knees had postoperative anatomic reduction (0mm step-off) and 6 had acceptable reduction (< 2mm step-off). At 34.4 ± 9.6 months, median extension was 3 (5-10) and flexion 135 (100-145). The mean Lysholm score was 95 (75-100) and the mean Tegner activity score was 6 (5-8). All patients were satisfied with the operation. No cases of post-traumatic osteoarthritis of the knee occurred during follow-up. The prone position and direct posterior approach has great advantages in terms of reduction and stable fixation, yielding good results. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  9. 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.

  10. Clocked Thrust Reversers

    NASA Technical Reports Server (NTRS)

    Suciu, Gabriel L. (Inventor); Chandler, Jesse M. (Inventor)

    2017-01-01

    An aircraft includes a fuselage including a propulsion system supported within an aft portion. A thrust reverser is mounted proximate to the propulsion system for directing thrust in a direction to slow the aircraft. The thrust reverser directs thrust at an angle relative to a vertical plane to reduce interference on control surfaces and reduce generation of underbody lift.

  11. Reverse Transfer Student Study.

    ERIC Educational Resources Information Center

    Slark, Julie

    After a preliminary study revealed that 21% of all credit students at Santa Ana College (SAC) had previously attended a four-year institution, a further study was conducted to determine the educational interests and matriculation patterns of these reverse transfer students. A sample of 360 reverse transfer students was selected for interviews,…

  12. 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.

  13. Hindfoot endoscopy for posterior ankle impingement.

    PubMed

    Scholten, P E; Sierevelt, I N; van Dijk, C N

    2008-12-01

    The surgical treatment of posterior ankle impingement is associated with a high rate of complications and a substantial time to recover. An endoscopic approach to the posterior ankle (hindfoot endoscopy) may lack these disadvantages. We hypothesized that hindfoot endoscopy causes less morbidity and facilitates a quick recovery compared with open surgery. Fifty-five consecutive patients with posterior ankle impingement were treated with an endoscopic removal of bone fragments and/or scar tissue. The symptoms were caused by trauma (65%) or overuse (35%). All patients were enrolled in a prospective protocol. At baseline, the age, sex, work and sports activities, American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot scores, and preinjury Tegner scores were determined for all patients. At the time of follow-up, AOFAS hindfoot scores and Tegner scores were assessed and the time to return to work and sports activities was determined. Complications were recorded. Patients scored the overall result as poor, fair, good, or excellent by means of a 4-point Likert scale. The median duration of follow-up was thirty-six months, and no patient was lost to follow-up. The median AOFAS hindfoot score increased from 75 points preoperatively to 90 points at the time of final follow-up. The median time to return to work and sports activities was two and eight weeks, respectively. At the time of follow-up, patients in the overuse group were more satisfied than those in the posttraumatic group, and the AOFAS hindfoot scores were higher in patients in the overuse group (median, 100 points) compared with patients in the posttraumatic group (median, 90 points). A complication occurred in one patient who had a temporary loss of sensation of the posteromedial aspect of the heel. The outcome after endoscopic treatment of posterior ankle impingement compares favorably with the results of open surgery reported in the literature. Hindfoot endoscopy appears to cause less morbidity than open

  14. Posterior SMA Syndrome following subcortical stroke: contralateral akinesia reversed by visual feedback.

    PubMed

    Radman, Narges; Cacioppo, Stephanie; Spierer, Lucas; Schmidlin, Eric; Mayer, Eugène; Annoni, Jean-Marie

    2013-11-01

    The supplementary motor area (SMA) plays a key role in motor programming and production and is involved in internally-cued movements. In neurological populations, SMA syndrome following a lesion to the "SMA proper" is characterized by transient impairment of voluntary movements and motor sequences. This syndrome is assumed to follow on from an interruption of the motor cortico-subcortical loop, and some case reports indicate that such a syndrome could occur after a brain lesion isolating the SMA from subcortical structures. To characterize the pattern of motor impairments in a patient whose stroke disconnects the SMA from the subcortical motor loop. A patient developed a moderate transient left hemiparesis following a subcortical stroke in the right anterior cerebral artery area, which disconnected the SMA from basal ganglia. Eight days after the stroke, when the hemiparesis had regressed, the patient presented a specific SMA motor disorder of the left hand which manifested as an akinesia and was exacerbated when his visual attention was not directed towards his hand. We assessed finger tapping with left and right hands, eyes closed and open, in the left and right hemispace. We indexed movement speed as the number of taps filmed over 5-s periods. Left motor weakness (grasping strength of right hand: 49 kg and left hand: 41 kg) was resolved in a week. Ideomotor and ideational gestures and motor sequences were preserved. On the tapping task, left-hand tapping was slower than right-hand tapping. Critically, visual feedback improved tapping speed for the left, but not for the right, hand. The hemispace of the task execution had no effect on tapping performance. Our results suggest that SMA-basal ganglia disconnection decreases contralateral movement initiation and maintenance and this effect is partly compensated by visual cues. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Neuropsychological improvement after posterior fossa arachnoid cyst drainage.

    PubMed

    Cuny, M L; Pallone, M; Piana, H; Boddaert, N; Sainte-Rose, C; Vaivre-Douret, L; Piolino, P; Puget, S

    2017-01-01

    Posterior fossa arachnoid cysts (PFAC) are mostly considered as benign lesions of the cerebellum. Although many studies have shown the major role of the cerebellum in modulating movement, language, cognition, and social interaction, there are few studies on the cognitive impact and surgical decompression of PFAC. We present the cases of two brothers successively diagnosed with PFAC and neuropsychological delay. After multidisciplinary discussion with the boys' parents, it was decided to drain these lesions. Clinical signs, cerebral images, and neuropsychological status were assessed on admission and then 1 and 3 years after surgery. At presentation, both children had mild cerebellar signs, associated with cognitive and visual-motor impairments and academic regression. CT scans revealed retrovermian cysts, which were shunted. Post-operatively, both brothers demonstrated improved visual-motor skills and behavior. At follow-up, we observed disappearance of dysarthria and academic delay and significant improvement in cognition especially at the intelligence scale and in language. Fine motor skills had improved but remained slower than the average and writing skills appeared limited. Except for PFAC which impair cerebrospinal fluid circulation or which are responsible for a significant mass effect, most PFAC are usually considered as "asymptomatic" and do not require surgical treatment. The two cases reported herein suggest that these lesions might be responsible for some associated but potentially reversible neuropsychological impairment. In the future, clinical assessment should include neuropsychological evaluation to help inform decision for surgical decompression in these children with PFAC.

  16. 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.

  17. Posterior ventricular anchoring neochordal repair of degenerative mitral regurgitation efficiently remodels and repositions posterior leaflet prolapse†

    PubMed Central

    Woo, Y. Joseph; MacArthur, John W.

    2013-01-01

    OBJECTIVES Mitral valve repair techniques for degenerative disease typically entail leaflet resection or neochordal construction, which may require extensive resection, leaflet detachment/reattachment, reliance on diseased native chords or precise neochordal measuring. Occasionally, impaired leaflet mobility, reduced coaptation surface and systolic anterior motion (SAM) may result. We describe a novel technique for addressing posterior leaflet prolapse/flail, which both simplifies repair and addresses these issues. METHODS Fifty-four patients (age 62 ± 11 years) with degenerative MR underwent this new repair, 36 of whom minimally-invasively. A CV5 Gore-Tex suture was placed into the posterior left ventricular myocardium underneath the prolapsing segment as an anchor. This suture was then used to imbricate a portion of the prolapsed segment into the ventricle, creating a smooth, broad, non-prolapsed coapting surface on a leaflet with preserved mobility, additional neochordal support and posteriorly positioned enough to preclude SAM. RESULTS Repair was successful in all patients. The mean MR grade was reduced from +3.8 to +0.1 with 50 of 54 patients having zero MR and 4 of the 54 having trace or mild MR. All patients had proper antero-posterior location of the coaptation line of a mean length of 10.2 mm, and preserved posterior leaflet mobility. No patients had SAM or mitral stenosis. All patients were discharged and are currently doing well. CONCLUSION This new technique facilitated efficient single-suture repair of the prolapsed posterior leaflet mitral regurgitation without the need for resection or sliding annuloplasty. It precluded the need for precise neochordal measurement and preserved the leaflet coaptation surface. PMID:23449863

  18. Talar Osteochondroma Fracture Presenting as Posterior Ankle Impingement.

    PubMed

    Ercin, Ersin; Bilgili, Mustafa Gokhan; Gamsizkan, Mehmet; Avsar, Serdar

    2016-05-01

    Osteochondromas are the most common benign bone tumors. They are usually asymptomatic and found incidentally. When symptomatic, the symptoms are usually due to its location and size. Fracture of an osteochondroma presenting as posterior ankle impingement is a rare condition. We describe a 22-year-old man with solitary exostosis who presented with a posterior ankle mass and posterior ankle impingement with 2 years of follow-up. Surgical intervention was the treatment of choice in this patient, and histologic examination revealed a benign osteochondroma. Osteochondromas found in the posterior aspect of the talus can be complicated by fracture due to persistent motion of the ankle. Talar osteochondroma should be included in the differential diagnosis of posterior ankle impingement causes. Posterior talar osteochondromas, especially when a stalk is present, should be treated surgically before it is more complicated by a fracture and posterior ankle impingement.

  19. Biomechanical effectiveness of an arthroscopic posterior bankart repair versus an open bone block procedure for posterior shoulder instability.

    PubMed

    Wellmann, Mathias; Bobrowitsch, Evgenij; Khan, Nicklas; Patzer, Thilo; Windhagen, Henning; Petersen, Wolf; Bohnsack, Michael

    2011-04-01

    The most effective surgical treatment for traumatic posterior shoulder instability remains unclear. An arthroscopic posterior Bankart repair is as effective as an open posterior bone block-capsulorrhaphy procedure regarding the restoration of humeral displacement with posterior and inferior forces. Controlled laboratory study. Biomechanical testing of 16 human shoulders was performed in 3 testing conditions: after ventilation (intact joint), after creation of a posteroinferior Bankart lesion with an additional cut of the posterior band of the inferior glenohumeral ligament, and after surgical shoulder stabilization. The shoulder stabilization was performed either by an open posterior bone block procedure and glenoid-based T-capsulorrhaphy or by an arthroscopic Bankart repair. Testing was performed in 2 positions-the sulcus test position and the jerk test position-with a passive humerus load of 50 N applied in the posterior, posteroinferior, and inferior directions. After the arthroscopic repair, there was no significant difference between the translation and the intact state for all tested directions. The bone block repair-capsulorrhaphy caused a significant decrease of posterior translation (sulcus test and jerk test positions) and posteroinferior translation (jerk test position). But the resulting posterior and posteroinferior translation was even significantly lower than the translation measured for the intact joints. However, the reduction of inferior translation, compared with that of the defect condition, was not significant after the bone block repair (sulcus test and jerk test positions). Compared with that of the intact joint, inferior translation after the bone block repair was significantly higher. The posterior bone block repair-capsulorrhaphy overcorrects posterior translation and does not effectively restore inferior stability, whereas the arthroscopic posterior Bankart repair restores posterior and inferior laxity of the intact joint. An arthroscopic

  20. Surgical management of posterior fossa metastases.

    PubMed

    Sunderland, Geraint J; Jenkinson, Michael D; Zakaria, Rasheed

    2016-12-01

    The diagnosis of brain metastases is associated with a poor prognosis reflecting uncontrolled primary disease that has spread to the relative sanctuary of the central nervous system. 20 % of brain metastases occur in the posterior fossa and are associated with significant morbidity. The risk of acute hydrocephalus and potential for sudden death means these metastases are often dealt with as emergency cases. This approach means a full pre-operative assessment and staging of underlying disease may be neglected and a proportion of patients undergo comparatively high risk surgery with little or no survival benefit. This study aimed to assess outcomes in patients to identify factors that may assist in case selection. We report a retrospective case series of 92 consecutive patients operated for posterior fossa metastases between 2007 and 2012. Routine demographic data was collected plus data on performance status, primary cancer site, details of surgery, adjuvant treatment and survival. The only independent positive prognostic factors identified on multivariate analysis were good performance status (if Karnofsky performance score >70, hazard ratio (HR) for death 0.36, 95 % confidence interval (CI) 0.18-0.69), adjuvant whole brain radiotherapy (HR 0.37, 95 % CI 0.21-0.65) and adjuvant chemotherapy where there was extracranial disease and non-synchronous presentation (HR 0.51, 95 % CI 0.31-0.82). Patients presenting with posterior fossa metastases may not be investigated as thoroughly as those with supratentorial tumours. Staging and assessment is essential however, and in the meantime emergencies related to tumour mass effect should be managed with steroids and cerebrospinal fluid diversion as required.

  1. Oral azithromycin for treatment of posterior blepharitis.

    PubMed

    Igami, Thais Zamudio; Holzchuh, Ricardo; Osaki, Tammy Hentona; Santo, Ruth Miyuki; Kara-Jose, Newton; Hida, Richard Y

    2011-10-01

    To evaluate the effects of oral azithromycin in patients with posterior blepharitis. Twenty-six eyes of 13 patients with posterior blepharitis diagnosed by a qualified ophthalmologist were enrolled in this study. Patients were instructed to use oral azithromycin 500 mg per day for 3 days in 3 cycles with 7-day intervals. Subjective clinical outcomes were graded and scored 1 day before and 30 days after the end of the treatment (53 days after initiating the treatment) based on severity scores of: (1) eyelid debris; (2) eyelid telangiectasia; (3) swelling of the eyelid margin; (4) redness of the eyelid margin; and (5) ocular mucus secretion. For the assessment of global efficacy, patients were asked by the investigator to rate the subjective symptoms (eyelid itching, ocular itching, eyelid hyperemia, ocular hyperemia, ocular mucus secretion, photophobia, foreign body sensation, and dry eye sensation) on a scale of 0 (no symptoms) to 5 (severe symptoms). Break-up time, Schirmer I test, corneal fluorescein staining score, and rose bengal staining score were also performed in all patients. All clinical outcomes scoring showed statistically significant improvement after oral azithromycin, except for eyelid swelling. Average subjective symptom grading improved statistically after treatment with oral azithromycin, except for eyelid hyperemia, photophobia, and foreign body sensation. Average tear film break-up time values showed statistically significant improvement after the treatment with oral azithromycin. No statistically significant improvement was observed on average values of Schirmer I test, corneal fluorescein staining score, and rose bengal staining score. The combination of multiple clinical parameters shown in this study supports the clinical efficacy of pulsed oral azithromycin therapy for the management of posterior blepharitis.

  2. Posterior surgery in high-grade spondylolisthesis.

    PubMed

    Lengert, R; Charles, Y P; Walter, A; Schuller, S; Godet, J; Steib, J-P

    2014-09-01

    High-grade L5-S1 spondylolisthesis alters sagittal spinopelvic balance, which can cause low back pain and progressive neurologic disorder. The present study assessed spondylolisthesis reduction and maintenance over time with L4-S1 versus L5-S1 fusion using a lever-arm system and posterior fusion combined with lumbosacral graft. Forty patients were operated on for symptomatic high-grade spondylolisthesis, 34 of whom had full pre- and post-operative radiological analysis, with a mean follow-up of 5.4years. There were 9 L5-S1 and 25 L4-S1 instrumentations. Analysis of spinopelvic and slipping parameters and the evolution of segmental lordosis compared results between L5-S1 and L4-S1 instrumentation. Mean Taillard spondylolisthesis index decreased from 64% to 37% (P=0.0001). Overall sagittal spinopelvic balance was not significantly changed. Overall L1-S1 and segmental L4-L5 lordosis were not affected by instrumentation. Mean L5-S1 segmental lordosis increased from 11° to 18°. There was loss of reduction from 19° to 14° with L5-S1 instrumentation, in contrast to maintained reduction with L4-S1 instrumentation (P=0.006). The lever-arm system provided anterior-posterior reduction of spondylolisthesis and corrected slippage. Postoperative change in overall sagittal spinopelvic balance was slight and constant. Posterior L4-S1 fusion provided better long-term control of L5-S1 lordosis reduction than the shorter L5-S1 fusion. Retrospective study of level IV. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  3. The effect of proximal tibial slope on dynamic stability testing of the posterior cruciate ligament- and posterolateral corner-deficient knee.

    PubMed

    Petrigliano, Frank A; Suero, Eduardo M; Voos, James E; Pearle, Andrew D; Allen, Answorth A

    2012-06-01

    Proximal tibial slope has been shown to influence anteroposterior translation and tibial resting point in the posterior cruciate ligament (PCL)-deficient knee. The effect of proximal tibial slope on rotational stability of the knee is unknown. Change in proximal tibial slope produced via osteotomy can influence both static translation and dynamic rotational kinematics in the PCL/posterolateral corner (PLC)-deficient knee. Controlled laboratory study. Posterior drawer, dial, and mechanized reverse pivot-shift (RPS) tests were performed on hip-to-toe specimens and translation of the lateral and medial compartments measured utilizing navigation (n = 10). The PCL and structures of the PLC were then sectioned. Stability testing was repeated, and compartmental translation was recorded. A proximal tibial osteotomy in the sagittal plane was then performed achieving either +5° or -5° of tibial slope variation, after which stability testing was repeated (n = 10). Analysis was performed using 1-way analysis of variance (ANOVA; α = .05). Combined sectioning of the PCL and PLC structures resulted in a 10.5-mm increase in the posterior drawer, 15.5-mm increase in the dial test at 30°, 14.5-mm increase in the dial test at 90°, and 17.9-mm increase in the RPS (vs intact; P < .05). Increasing the posterior slope (high tibial osteotomy [HTO] +5°) in the PCL/PLC-deficient knee reduced medial compartment translation by 3.3 mm during posterior drawer (vs deficient; P < .05) but had no significant effect on the dial test at 30°, dial test at 90°, or RPS. Conversely, reversing the slope (HTO -5°) caused a 4.8-mm increase in medial compartment translation (vs deficient state; P < .05) during posterior drawer and an 8.6-mm increase in lateral compartment translation and 9.0-mm increase in medial compartment translation during RPS (vs deficient state; P < .05). Increasing posterior tibial slope diminished static posterior instability of the PCL/PLC-deficient knee as measured by the

  4. [Posterior dislocation of the sternoclavicular joint].

    PubMed

    Mäkinen, Tatu; Madanat, Rami; Heinänen, Mikko; Brinck, Tuomas; Pajarinen, Jarkko

    2013-01-01

    Posterior dislocation of the sternoclavicular joint is a rare injury. It can be associated with life-threatening complications. Computed tomography is the imaging modality of choice with which possible associated injuries can be detected. Acute injuries are managed with closed reduction under general anaesthesia. A fracture-dislocation is inherently more unstable than an isolated dislocation. Surgical treatment is advocated in cases of delayed diagnosis or failed closed reduction. With early diagnosis and treatment, the long-term outcome of this injury is good.

  5. [Desmoid fibromatosis of the posterior mediastinum].

    PubMed

    Ayadi-Kaddour, A; Chaabouni, N; Smati, B; Mehouachi, R; Djilani, H; El Mezni, F

    2008-01-01

    Fibromatosis are uncommon connective tissue tumours arising from musculo-aponeurotic tissue and characterised by spindle cell fibroblastic and myofibroblastic proliferation. The exact aetiology is unknown but several factors are considered to be positively correlated with their development and growth (genetic and hormonal factors and trauma). Although they are considered histologically benign they behave aggressively locally and relapse repeatedly after surgical excision. Mediastinal localisation is very rare. We describe a case of de novo fibromatosis of the posterior mediastinum in a 61 year old man with no history of thoracotomy or trauma. Although mediastinal fibromatosis is very uncommon physicians should be aware of this disease in order to ensure appropriate surgical treatment.

  6. Exploring Posterior Distributions Using Markov Chains

    DTIC Science & Technology

    1992-01-01

    ibutio;. T I..... i~it c..... 1 Q ELECTE JUL23 1992 Dist U S , D A0 This document ha beon approsd for publc release and sa* its distribution Is unlimitd...uniform, and Hastings (1970) and explored further by Peskun (1973). dmrwal . a t disto n frewa, 1989)rmayTo dfin Hatins vesio ofthealgoith, lt Qbe t...that direction, van Dijk, H. K., 3. P. Ilop, and A. S . Louter (1978). An algorithm for the computation of posterior moments and densities using simple

  7. Posterior breast cancer - mammographic and ultrasonographic features.

    PubMed

    Janković, Ana; Nadrljanski, Mirjan; Karapandzić, Vesna Plesinac; Ivanović, Nebojsa; Radojicić, Zoran; Milosević, Zorica

    2013-11-01

    Posterior breast cancers are located in the prepectoral region of the breast. Owing to this distinctive anatomical localization, physical examination and mammographic or ultrasonographic evaluation can be difficult. The purpose of the study was to assess possibilities of diagnostic mammography and breast ultrasonography in detection and differentiation of posterior breast cancers. The study included 40 women with palpable, histopathological confirmed posterior breast cancer. Mammographic and ultrasonographic features were defined according to Breast Imaging Reporting and Data System (BI-RADS) lexicon. Based on standard two-view mammography 87.5%, of the cases were classified as BI-RADS 4 and 5 categories, while after additional mammographic views all the cases were defined as BI-RADS 4 and 5 categories. Among 96 mammographic descriptors, the most frequent were: spiculated mass (24.0%), architectural distortion (16.7%), clustered micro-calcifications (12.6%) and focal asymmetric density (12.6%). The differentiation of the spiculated mass was significantly associated with the possibility to visualize the lesion at two-view mammography (p = 0.009), without the association with lesion diameter (p = 0.083) or histopathological type (p = 0.055). Mammographic signs of invasive lobular carcinoma were significantly different from other histopathological types (architectural distortion, p = 0.003; focal asymmetric density, p = 0.019; association of four or five subtle signs of malignancy, p = 0.006). All cancers were detectable by ultrasonography. Mass lesions were found in 82.0% of the cases. Among 153 ultrasonographic descriptors, the most frequent were: irregular mass (15.7%), lobulated mass (7.2%), abnormal color Doppler signals (20.3%), posterior acoustic attenuation (18.3%). Ultrasonographic BI-RADS 4 and 5 categories were defined in 72.5% of the cases, without a significant difference among various histopathological types (p = 0.109). Standard two-view mammography

  8. Biomechanical evaluation of a novel dynamic posterior cruciate ligament brace.

    PubMed

    Heinrichs, Christian H; Schmoelz, Werner; Mayr, Raul; Keiler, Alexander; Schöttle, Philip B; Attal, René

    2016-03-01

    Use of a rigid brace or cast immobilization is recommended in conservative treatment or postoperative rehabilitation after a posterior cruciate ligament injury. To prevent the loss of knee joint function and muscle activity often associated with this, a flexible knee brace has been developed that allows an adjustable anteriorly directed force to be applied to the calf in order to prevent posterior tibial translation. The purpose of this biomechanical study was to evaluate the impact of this novel dynamic brace on posterior tibial translation after posterior cruciate ligament injury and reconstruction. A Telos stress device was used to provoke posterior tibial translation in seven human lower limb specimens, and stress radiographs were taken at 90° of knee flexion. Posterior tibial translation was measured in the native knees with an intact posterior cruciate ligament; after arthroscopic posterior cruciate ligament dissection with and without a brace; and after posterior cruciate ligament reconstruction with and without a brace. The force applied with the brace was measured using a pressure sensor. Posterior tibial translation was significantly reduced (P=0.032) after application of the brace with an anteriorly directed force of 50N to the knees with the dissected posterior cruciate ligament. The brace also significantly reduced posterior tibial translation after posterior cruciate ligament reconstruction in comparison with reconstructed knees without a brace (P=0.005). Posterior tibial translation was reduced to physiological values using this dynamic brace system that allows an anteriorly directed force to be applied to the calf. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. An algebra of reversible computation.

    PubMed

    Wang, Yong

    2016-01-01

    We design an axiomatization for reversible computation called reversible ACP (RACP). It has four extendible modules: basic reversible processes algebra, algebra of reversible communicating processes, recursion and abstraction. Just like process algebra ACP in classical computing, RACP can be treated as an axiomatization foundation for reversible computation.

  10. Decompression of Posterior Ankle Impingement With Concomitant Anterior Ankle Pathology by Posterior Ankle Arthroscopy in the Supine Position.

    PubMed

    Lui, Tun Hing

    2016-10-01

    Posterior ankle endoscopy is a safe and effective approach for treatment of posterior ankle impingement. This is usually performed with the patient in prone position. The purpose of this technical note is to describe an arthroscopic approach of decompression of posterior ankle impingement with the patient in supine position. This is indicated if there is posterior ankle impingement together with other ankle pathology requiring anterior ankle arthroscopy. This approach allows treatment of both anterior ankle and posterior ankle pathology with the patient in the supine position. Concomitant anterior ankle arthroscopy can be performed with the usual orientation without the need of change of patient's position.

  11. Reversible shape memory

    NASA Astrophysics Data System (ADS)

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

    2012-02-01

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

  12. Reversing the arms race

    SciTech Connect

    von Hippel, F. ); Sagdeev, R.Z. )

    1992-01-01

    This paper contains proceedings of Reversing The Arms Race. Topics covered include: Verifying Reductions of Nuclear Warheads; Verifying Limits on Nuclear-Armed Cruise Missiles; and The Technical Basis for Warhead Detection.

  13. 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

  14. Posterior malleolar fractures of the ankle.

    PubMed

    Bartoníček, J; Rammelt, S; Tuček, M; Naňka, O

    2015-12-01

    Despite an increasing awareness of injuries to PM in ankle fracture-dislocations, there are still many open questions. The mere presence of a posterior fragment leads to significantly poorer outcomes. Adequate diagnosis, classification and treatment require preoperative CT examination, preferably with 3D reconstructions. The indication for surgical treatment is made individually on the basis of comprehensive assessment of the three-dimensional outline of the PM fracture and all associated injuries to the ankle including syndesmotic instability. Anatomic fixation of the avulsed posterior tibiofibular ligament will contribute to syndesmotic stability and restore the integrity of the incisura tibiae thus facilitating anatomic reduction of the distal fibula. A necessary prerequisite is mastering of posterolateral and posteromedial approaches and the technique of direct reduction and internal fixation. Further clinical studies with higher numbers of patients treated by similar methods and evaluation of pre- and postoperative CT scans will be necessary to determine reliable prognostic factors associated with certain types of PM fractures and associated injuries to the ankle.

  15. Posterior repair with perforated porcine dermal graft.

    PubMed

    Taylor, G Bernard; Moore, Robert D; Miklos, John R; Mattox, T Fleming

    2008-01-01

    To compare postoperative vaginal incision separation and healing in patients undergoing posterior repair with perforated porcine dermal grafts with those that received grafts without perforations. Secondarily, the tensile properties of the perforated and non-perforated grafts were measured and compared. This was a non-randomized retrospective cohort analysis of women with stage II or greater rectoceles who underwent posterior repair with perforated and non-perforated porcine dermal grafts (Pelvicol(TM) CR Bard Covington, GA USA). The incidence of postoperative vaginal incision separation (dehiscence) was compared. A secondary analysis to assess graft tensile strength, suture pull out strength, and flexibility after perforation was performed using standard test method TM 0133 and ASTM bending and resistance protocols. Seventeen percent of patients (21/127) who received grafts without perforations developed vaginal incision dehiscence compared to 7% (5/71) of patients who received perforated grafts (p = 0.078). Four patients with vaginal incision dehiscence with non-perforated grafts required surgical revision to facilitate healing. Neither tensile strength or suture pull out strength were significantly different between perforated and non-perforated grafts (p = 0.81, p = 0.29, respectively). There was no difference in the flexibility of the two grafts (p = 0.20). Perforated porcine dermal grafts retain their tensile properties and are associated with fewer vaginal incision dehiscences.

  16. 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

  17. Hydatidosis of the liver and posterior mediastinum.

    PubMed

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

    2015-01-01

    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. 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. 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. 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. Published by Elsevier Ltd.

  18. 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.

  19. Microsurgical anatomy of the posterior fossa cisterns.

    PubMed

    Matsuno, H; Rhoton, A L; Peace, D

    1988-07-01

    The microsurgical anatomy of the posterior fossa cisterns was examined in 15 cadavers using 3X to 40X magnification. Liliequist's membrane was found to split into two arachnoidal sheets as it spreads upward from the dorsum sellae: an upper sheet, called the diencephalic membrane, which attaches to the diencephalon at the posterior edge of the mamillary bodies, and a lower sheet, called the mesencephalic membrane, which attaches along the junction of the midbrain and pons. Several other arachnoidal membranes that separate the cisterns were identified. These include the anterior pontine membrane, which separates the prepontine and cerebellopontine cisterns; the lateral pontomesencephalic membrane, which separates the ambient and cerebellopontine cisterns; the medial pontomedullary membrane, which separates the premedullary and prepontine cisterns; and the lateral pontomedullary membrane, which separates the cerebellopontine and cerebellomedullary cisterns. The three cisterns in which the arachnoid trabeculae and membranes are the most dense and present the greatest obstacle at operation are the interpeduncular and quadrigeminal cisterns and the cisterna magna. Numerous arachnoid membranes were found to intersect the oculomotor nerves. The neural and vascular structures in each cistern are reviewed.

  20. 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…

  1. GNSS integer ambiguity validation based on posterior probability

    NASA Astrophysics Data System (ADS)

    Wu, Zemin; Bian, Shaofeng

    2015-10-01

    GNSS integer ambiguity validation is considered to be a challenge task for decades. Several kinds of validation tests are developed and widely used in these years, but theoretical basis is their weakness. Ambiguity validation theoretically is an issue of hypothesis test. In the frame of Bayesian hypothesis testing, posterior probability is the canonical standard that statistical decision should be based on. In this contribution, (i) we derive the posterior probability of the fixed ambiguity based on the Bayesian principle and modify it for practice ambiguity validation. (ii) The optimal property of the posterior probability test is proved based on an extended Neyman-Pearson lemma. Since validation failure rate is the issue users most concerned about, (iii) we derive the failure rate upper bound of the posterior probability test, so the user can use the posterior probability test either in the fixed posterior probability or in the fixed failure rate way. Simulated as well as real observed data are used for experimental validations. The results show that (i) the posterior probability test is the most effective within the R-ratio test, difference test, ellipsoidal integer aperture test and posterior probability test, (ii) the posterior probability test is computational efficient and (iii) the failure rate estimation for posterior probability test is useful.

  2. Visual input to the mouse lateral posterior and posterior thalamic nuclei: photoreceptive origins and retinotopic order

    PubMed Central

    Allen, Annette E.; Procyk, Christopher A.; Howarth, Michael; Walmsley, Lauren

    2016-01-01

    Key points The lateral posterior and posterior thalamic nuclei have been implicated in aspects of visually guided behaviour and reflex responses to light, including those dependent on melanopsin photoreception.Here we investigated the extent and basic properties of visually evoked activity across the mouse lateral posterior and posterior thalamus.We show that a subset of retinal projections to these regions derive from melanopsin‐expressing retinal ganglion cells and find many cells that exhibit melanopsin‐dependent changes in firing.We also show that subsets of cells across these regions integrate signals from both eyes in various ways and that, within the lateral posterior thalamus, visual responses are retinotopically ordered. Abstract In addition to the primary thalamocortical visual relay in the lateral geniculate nuclei, a number of other thalamic regions contribute to aspects of visual processing. Thus, the lateral posterior thalamic nuclei (LP/pulvinar) appear important for various functions including determining visual saliency, visually guided behaviours and, alongside dorsal portions of the posterior thalamic nuclei (Po), multisensory processing of information related to aversive stimuli. However, despite the growing importance of mice as a model for understanding visual system organisation, at present we know very little about the basic visual response properties of cells in the mouse LP or Po. Prompted by earlier suggestions that melanopsin photoreception might be important for certain functions of these nuclei, we first employ specific viral tracing to show that a subset of retinal projections to the LP derive from melanopsin‐expressing retinal ganglion cells. We next use multielectrode electrophysiology to demonstrate that LP and dorsal Po cells exhibit a variety of responses to simple visual stimuli including two distinct classes that express melanopsin‐dependent changes in firing (together comprising ∼25% of neurons we recorded). We also

  3. Visual input to the mouse lateral posterior and posterior thalamic nuclei: photoreceptive origins and retinotopic order.

    PubMed

    Allen, Annette E; Procyk, Christopher A; Howarth, Michael; Walmsley, Lauren; Brown, Timothy M

    2016-04-01

    The lateral posterior and posterior thalamic nuclei have been implicated in aspects of visually guided behaviour and reflex responses to light, including those dependent on melanopsin photoreception. Here we investigated the extent and basic properties of visually evoked activity across the mouse lateral posterior and posterior thalamus. We show that a subset of retinal projections to these regions derive from melanopsin-expressing retinal ganglion cells and find many cells that exhibit melanopsin-dependent changes in firing. We also show that subsets of cells across these regions integrate signals from both eyes in various ways and that, within the lateral posterior thalamus, visual responses are retinotopically ordered. In addition to the primary thalamocortical visual relay in the lateral geniculate nuclei, a number of other thalamic regions contribute to aspects of visual processing. Thus, the lateral posterior thalamic nuclei (LP/pulvinar) appear important for various functions including determining visual saliency, visually guided behaviours and, alongside dorsal portions of the posterior thalamic nuclei (Po), multisensory processing of information related to aversive stimuli. However, despite the growing importance of mice as a model for understanding visual system organisation, at present we know very little about the basic visual response properties of cells in the mouse LP or Po. Prompted by earlier suggestions that melanopsin photoreception might be important for certain functions of these nuclei, we first employ specific viral tracing to show that a subset of retinal projections to the LP derive from melanopsin-expressing retinal ganglion cells. We next use multielectrode electrophysiology to demonstrate that LP and dorsal Po cells exhibit a variety of responses to simple visual stimuli including two distinct classes that express melanopsin-dependent changes in firing (together comprising ∼25% of neurons we recorded). We also show that subgroups of LP

  4. The Effect of Hinge Position on Posterior Tibial Slope in Medial Open-Wedge High Tibial Osteotomy.

    PubMed

    Moon, Sang Won; Park, Sin Hyung; Lee, Byung Hoon; Oh, Minkyung; Chang, Minho; Ahn, Jin Hwan; Wang, Joon Ho

    2015-06-01

    To evaluate whether hinge position affects the change in posterior tibial slope in medial open-wedge high tibial osteotomy (HTO). We retrospectively evaluated 19 knees from 17 patients who underwent medial open-wedge HTO by 3-dimensional computed tomography scan before and after surgery. A 3-dimensional image model was constructed by applying reverse-engineering software to the computed tomography DICOM (Digital Imaging and Communications in Medicine) files. The hinge axis (i.e., the position of the hinge compared with the anteroposterior axis on an axial view), posterior tibial slope, medial-proximal tibial angle, and gap ratio (i.e., the ratio of anterior gap to posterior gap in the opened wedge) were measured. The mean hinge axis was 4.92° ± 3.86°. Posterior tibial slope increased from 7.29° ± 2.56° preoperatively to 10.48° ± 3.01° postoperatively (P = .001). The mean medial-proximal tibial angle was 85.96° ± 1.97° preoperatively and 93.13° ± 3.17° postoperatively (P = .001). The mean gap ratio was 62.48% ± 7.26%. Linear regression analysis determined that the hinge axis (P = .0001) was a significant factor changing posterior tibial slope. Hinge position affected the change in posterior tibial slope in medial open-wedge HTO; in particular, a posterolateral hinge position led to an increase in posterior tibial slope. Level IV, therapeutic study. Copyright © 2015 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

  5. On thermodynamic and microscopic reversibility

    SciTech Connect

    Crooks, Gavin E.

    2011-07-12

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

  6. The effect of posterior tibial slope on knee flexion in posterior-stabilized total knee arthroplasty.

    PubMed

    Shi, Xiaojun; Shen, Bin; Kang, Pengde; Yang, Jing; Zhou, Zongke; Pei, Fuxing

    2013-12-01

    To evaluate and quantify the effect of the tibial slope on the postoperative maximal knee flexion and stability in the posterior-stabilized total knee arthroplasty (TKA). Fifty-six patients (65 knees) who had undergone TKA with the posterior-stabilized prostheses were divided into the following 3 groups according to the measured tibial slopes: Group 1: ≤4°, Group 2: 4°-7° and Group 3: >7°. The preoperative range of the motion, the change in the posterior condylar offset, the elevation of the joint line, the postoperative tibiofemoral angle and the preoperative and postoperative Hospital for Special Surgery (HSS) scores were recorded. The tibial anteroposterior translation was measured using the Kneelax 3 Arthrometer at both the 30° and the 90° flexion angles. The mean values of the postoperative maximal knee flexion were 101° (SD 5), 106° (SD 5) and 113° (SD 9) in Groups 1, 2 and 3, respectively. A significant difference was found in the postoperative maximal flexion between the 3 groups (P < 0.001). However, no significant differences were found between the 3 groups in the postoperative HSS scores, the changes in the posterior condylar offset, the elevation of the joint line or the tibial anteroposterior translation at either the 30° or the 90° flexion angles. A 1° increase in the tibial slope resulted in a 1.8° flexion increment (r = 1.8, R (2) = 0.463, P < 0.001). An increase in the posterior tibial slope can significantly increase the postoperative maximal knee flexion. The tibial slope with an appropriate flexion and extension gap balance during the operation does not affect the joint stability.

  7. Grammont reverse prosthesis: design, rationale, and biomechanics.

    PubMed

    Boileau, Pascal; Watkinson, Duncan J; Hatzidakis, Armodios M; Balg, Frederic

    2005-01-01

    Combined destruction of the rotator cuff and the glenohumeral joint may lead to a painful and pseudo-paralyzed shoulder. In this situation a nonconstrained shoulder prosthesis yields a limited functional result or may even be contraindicated. Previous constrained prostheses (ball-and-socket or reverse ball-and-socket designs) have failed because their center of rotation remained lateral to the scapula, which limited motion and produced excessive torque on the glenoid component, leading to early loosening. The reverse prosthesis designed by Paul Grammont, unlike any previous reverse ball-and-socket design, has introduced 2 major innovations that have led to its success: (1) a large glenoid hemisphere with no neck and (2) a small humeral cup almost horizontally oriented with a nonanatomic inclination of 155 degrees, covering less than half of the glenosphere. This design medializes and stabilizes the center of rotation, minimizes torque on the glenoid component, and helps in recruiting more fibers of the anterior and posterior deltoid to act as abductors. Furthermore, the humerus is lowered relative to the acromion, restoring and even increasing deltoid tension. The Grammont reverse prosthesis imposes a new biomechanical environment for the deltoid muscle to act, thus allowing it to compensate for the deficient rotator cuff muscles. The clinical experience does live up to the biomechanical concept: the reverse prosthesis restores active elevation above 90 degrees in patients with a cuff-deficient shoulder. However, external rotation often remains limited, particularly in patients with an absent or fat-infiltrated teres minor. Internal rotation is also rarely restored after a reverse prosthesis. Failure to restore sufficient tension in the deltoid may result in prosthetic instability. The design does appear to protect against early loosening of the glenoid component, but impingement of the humeral cup on the scapular neck can lead to scapular notching and polyethylene

  8. Reversible collisionless magnetic reconnection

    SciTech Connect

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

    2013-10-15

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

  9. 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.

  10. Hemifacial spasm and posterior auricular muscle.

    PubMed

    Kiziltan, M; Sahin, R; Uzun, N; Kiziltan, G

    2006-09-01

    We aimed to investigate to which extent posterior auricular muscle (PAM) was affected and whether it contributed to the reflex activity in hemifacial spasm (HFS) patients. 19 HFS patients' spasm activities were recorded from facial muscles. Spasm activity of PAM was recorded synchronously on the symptomatic side in all patients. Lateral spread of blink reflex to orbicularis oris and PAMs were recorded in all but two patients. Botulinum toxin was applied to the PAM with the 14 patients presenting tinnitus, "clicking" or a "ticking" sound on the sane side and other positive auricular symptoms. After treatment, there was symptomatic improvement in 9 of 14 patients. The patients presenting with auricular symptoms and showing spasm activity in their PAMs can be thought as a candidate for botulinum toxin treatment scheme.

  11. [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.

  12. Polycythemia causing posterior segment vascular occlusions

    PubMed Central

    Ganesan, Suganeswari; Raman, Rajiv; Sharma, Tarun

    2017-01-01

    A 44-year-old male patient presented with features suggestive of transient central retinal artery occlusion (CRAO) followed by permanent CRAO and lateral posterior ciliary artery occlusion. He had diagnostic features of polycythemia vera (PV). When presented for the first time, the patient had features of ocular ischemia such as ocular pain, conjunctival congestion, and retinal opacification but with normal arm-to-retina time and normal arteriovenous transit time. During the second presentation, he had ocular pain, congested conjunctiva, retinal opacification, cherry red spot with box-carrying of retinal vessels, and choroidal infarct (Amalric's sign). He had lost light perception in that eye. Patients with polycythemia are prone to multifocal vascular occlusions and this can be the presenting feature in PV. A timely diagnosis and prompt management can prevent these repeated thromboembolic occlusive episodes. PMID:28298862

  13. 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

  14. Muscle complex saving posterior sagittal anorectoplasty.

    PubMed

    Zaiem, Maher; Zaiem, Feras

    2017-05-01

    Posterior sagittal anorectoplasty (PSARP) published by DeVries and Peña in 1982 had become the preferred surgical technique for the management of anorectal malformations (ARM). The original technique is based upon complete exposure of the anorectal region by means of a median sagittal incision that runs from the sacrum to the anal dimple, cutting through all muscle structures behind the rectum by dividing the levator muscle and the muscle complex. Then, the rectum is located in front of the levator and within the limits of the muscle complex. In this review, we described Muscle Complex Saving-Posterior Sagittal Anorectoplasty (MCS-PSARP), which is a less invasive technique that consists of keeping this funnel-shaped muscle complex completely intact and not divided, and pulling the rectum through this funnel, toward fixing the new anus to the skin. This technique aimed both to respect the lower part of the sphincter mechanism consisting of the muscle complex, and to avoid the disturbance of this important structure by dividing and resuturing it. We presented six cases of male patients who were born with anorectal malformation (ARM) and underwent MCS-PSARP. The surgical technique proved to be feasible to achieve the dissection of the rectal pouch and the division of the rectourethral fistula in all patients, by opening only the upper part of the sphincter mechanism, the levator muscle, and keeping the lower part consisting of intact muscle complex. The early results in our series are encouraging; however, long-term functional outcomes of these patients are awaited. The surgical tips were also discussed. This proposed approach in the management of anorectal malformation cases provides an opportunity to maximize preservation of the existing continence mechanisms. It preserves the muscle complex components of the levator muscle intact, allowing a better function of the continence mechanism. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Reversibility of liver fibrosis.

    PubMed

    Sun, Mengxi; Kisseleva, Tatiana

    2015-09-01

    Liver fibrosis is a serious health problem worldwide, which can be induced by a wide spectrum of chronic liver injuries. However, until today, there is no effective therapy available for liver fibrosis except the removal of underlying etiology or liver transplantation. Recent studies indicate that liver fibrosis is reversible when the causative agent(s) is removed. Understanding of mechanisms of liver fibrosis regression will lead to the identification of new therapeutic targets for liver fibrosis. This review summarizes recent research progress on mechanisms of reversibility of liver fibrosis. While most of the research has been focused on HSCs/myofibroblasts and inflammatory pathways, the crosstalk between different organs, various cell types and multiple signaling pathways should not be overlooked. Future studies that lead to fully understanding of the crosstalk between different cell types and the molecular mechanism underlying the reversibility of liver fibrosis will definitely give rise to new therapeutic strategies to treat liver fibrosis.

  16. 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.

  17. Dynamics of magnetization reversal

    NASA Astrophysics Data System (ADS)

    Safonov, Vladimir L.

    2000-03-01

    Advanced magnetic recording systems are designed for extremely high areal densities and data rate. These two aspects require both magnetization reversal at very short times (< 1 ns) and long term ( ~ 5-10 years) stability against thermal fluctuations. There are two basic physics problems associated with these requirements. The first is a characterization of thermal-dynamic reversal over very wide time range. The second is an understanding of the physics of the relaxation mechanisms. Both these subjects will be reviewed in this talk. Thermal dynamic reversal requires solution of the Landau-Lifshitz equation with fluctuations. We have solved this problem in terms of the ``random walk" dynamics of a nonlinear oscillator [1,2]. The expressions for the switching field versus pulse time are analytic and show good agreement with measurements on CrO_2. Our studies of fundamental relaxation mechanisms have involved a two step approach. First the results of computer simulations of magnetization reversal without phenomenological damping will be discussed. In this case coherent rotation of the magnetization excites spin waves during which an excess of Zeeman energy is transformed to anisotropy and exchange energies. However, for fine grains whose size is sufficiently small so that the grain magnetization is virtually uniform, non-linear spin waves cannot assist reversal [3]. A new analytic model of reversal that couples coherent rotation to impurity ions by an anisotropic exchange mechanism will be discussed. These impurity ions are assumed to relax at a very high rate to the lattice. [1] V.L.Safonov, JMMM 195, 523 (1999); J.Appl.Phys. 85, 4370 (1999). [2] V.L.Safonov, H.N.Bertram, MMM'99, CU-09. [3] V.L.Safonov, H.N.Bertram, J.Appl.Phys. 85, 5072 (1999); MMM'99, CD-11.

  18. Reverse shoulder arthroplasty.

    PubMed

    Jarrett, Claudius D; Brown, Brandon T; Schmidt, Christopher C

    2013-07-01

    The reverse shoulder arthroplasty is considered to be one of the most significant technological advancements in shoulder reconstructive surgery over the past 30 years. It is able to successfully decrease pain and improve function for patients with rotator cuff-deficient shoulders. The glenoid is transformed into a sphere that articulates with a humeral socket. The current reverse prosthesis shifts the center of rotation more medial and distal, improving the deltoid's mechanical advantage. This design has resulted in successful improvement in both active shoulder elevation and in quality of life. Copyright © 2013 Elsevier Inc. All rights reserved.

  19. 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

  20. Sequential Polarity-Reversing Circuit

    NASA Technical Reports Server (NTRS)

    Labaw, Clayton C.

    1994-01-01

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

  1. Sequential Polarity-Reversing Circuit

    NASA Technical Reports Server (NTRS)

    Labaw, Clayton C.

    1994-01-01

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

  2. Effect of reverse shoulder design philosophy on muscle moment arms.

    PubMed

    Hamilton, Matthew A; Diep, Phong; Roche, Chris; Flurin, Pierre Henri; Wright, Thomas W; Zuckerman, Joseph D; Routman, Howard

    2015-04-01

    This study analyzes the muscle moment arms of three different reverse shoulder design philosophies using a previously published method. Digital bone models of the shoulder were imported into a 3D modeling software and markers placed for the origin and insertion of relevant muscles. The anatomic model was used as a baseline for moment arm calculations. Subsequently, three different reverse shoulder designs were virtually implanted and moment arms were analyzed in abduction and external rotation. The results indicate that the lateral offset between the joint center and the axis of the humerus specific to one reverse shoulder design increased the external rotation moment arms of the posterior deltoid relative to the other reverse shoulder designs. The other muscles analyzed demonstrated differences in the moment arms, but none of the differences reached statistical significance. This study demonstrated how the combination of variables making up different reverse shoulder designs can affect the moment arms of the muscles in different and statistically significant ways. The role of humeral offset in reverse shoulder design has not been previously reported and could have an impact on external rotation and stability achieved post-operatively. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  3. 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.

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

    PubMed

    Calandrelli, Rosalinda; D'Apolito, Gabriella; Marco, Panfili; Zampino, Giuseppe; Tartaglione, Tommaso; Colosimo, Cesare

    2015-06-01

    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.

  5. 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

  6. Cadaveric and three-dimensional computed tomography study of the morphology of the scapula with reference to reversed shoulder prosthesis.

    PubMed

    Torrens, Carlos; Corrales, Monica; Gonzalez, Gemma; Solano, Alberto; Cáceres, Enrique

    2008-10-10

    The purpose of this study is to analyze the morphology of the scapula with reference to the glenoid component implantation in reversed shoulder prosthesis, in order to improve primary fixation of the component. Seventy-three 3-dimensional computed tomography of the scapula and 108 scapular dry specimens were analyzed to determine the anterior and posterior length of the glenoid neck, the angle between the glenoid surface and the upper posterior column of the scapula and the angle between the major craneo-caudal glenoid axis and the base of the coracoid process and the upper posterior column. The anterior and posterior length of glenoid neck was classified into two groups named "short-neck" and "long-neck" with significant differences between them. The angle between the glenoid surface and the upper posterior column of the scapula was also classified into two different types: type I (mean 50 degrees-52 degrees ) and type II (mean 62.50 degrees-64 degrees ), with significant differences between them (p < 0.001). The angle between the major craneo-caudal glenoid axis and the base of the coracoid process averaged 18,25 degrees while the angle with the upper posterior column of the scapula averaged 8 degrees . Scapular morphological variability advices for individual adjustments of glenoid component implantation in reversed total shoulder prosthesis. Three-dimensional computed tomography of the scapula constitutes an important tool when planning reversed prostheses implantation.

  7. Cadaveric and three-dimensional computed tomography study of the morphology of the scapula with reference to reversed shoulder prosthesis

    PubMed Central

    Torrens, Carlos; Corrales, Monica; Gonzalez, Gemma; Solano, Alberto; Cáceres, Enrique

    2008-01-01

    Purpose The purpose of this study is to analyze the morphology of the scapula with reference to the glenoid component implantation in reversed shoulder prosthesis, in order to improve primary fixation of the component. Methods Seventy-three 3-dimensional computed tomography of the scapula and 108 scapular dry specimens were analyzed to determine the anterior and posterior length of the glenoid neck, the angle between the glenoid surface and the upper posterior column of the scapula and the angle between the major craneo-caudal glenoid axis and the base of the coracoid process and the upper posterior column. Results The anterior and posterior length of glenoid neck was classified into two groups named "short-neck" and "long-neck" with significant differences between them. The angle between the glenoid surface and the upper posterior column of the scapula was also classified into two different types: type I (mean 50°–52°) and type II (mean 62,50°–64°), with significant differences between them (p < 0,001). The angle between the major craneo-caudal glenoid axis and the base of the coracoid process averaged 18,25° while the angle with the upper posterior column of the scapula averaged 8°. Conclusion Scapular morphological variability advices for individual adjustments of glenoid component implantation in reversed total shoulder prosthesis. Three-dimensional computed tomography of the scapula constitutes an important tool when planning reversed prostheses implantation. PMID:18847487

  8. Mutations in FLVCR1 cause posterior column ataxia and retinitis pigmentosa.

    PubMed

    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

    2010-11-12

    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. Copyright © 2010 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

  9. Posterior interhemispheric retrocallosal approach to pineal region and posterior fossa lesions in a pediatric population.

    PubMed

    Davidson, Laurence; Krieger, Mark D; McComb, J Gordon

    2011-05-01

    The purpose of this study was to evaluate the posterior interhemispheric retrocallosal approach (PIRA) for its safety and efficacy in the resection of pineal region and posterior fossa lesions in children. Twenty-nine PIRAs were performed in 26 children between March 1997 and March 2009, and these cases were retrospectively reviewed. There were 15 girls and 11 boys in the series. The median age at the time of surgery was 7 years (range 7 months-17 years). Twenty-seven cases were treated for tumor, 1 for loculated hydrocephalus, and 1 for an aneurysm. Of the 27 cases treated for tumor, there were 20 (74%) gross-total resections, 5 (19%) subtotal resections, and 2 (7%) biopsies. One bridging vein was sacrificed in 6 cases and 2 bridging veins were divided in 1 case, whereas in 3 cases there was sacrifice of a single deep cerebral vein. No patient developed radiographic evidence of venous infarction. Approach-related complications were low, and included 2 cases of transient homonymous hemianopia. There were no surgery-related deaths. This approach allows for ample access to pineal region and posterior fossa lesions, with low postoperative morbidity.

  10. Varieties of Alexia From Fusiform, Posterior Inferior Temporal and Posterior Occipital Gyrus Lesions

    PubMed Central

    Sakurai, Yasuhisa

    2004-01-01

    Reading impairments of three alexia patients, two pure alexia and one alexia with agraphia, due to different lesions were examined quantitatively, using Kanji (Japanese morphogram) words, Kana (Japanese phonetic writing) words and Kana nonwords. Kana nonword reading was impaired in all three patients, suggesting that widespread areas in the affected occipital and occipitotemporal cortices were recruited in reading Kana characters (corresponding to European syllables). In addition, the findings in patient 1 (pure alexia for Kanji and Kana from a fusiform and lateral occipital gyri lesion) and patient 2 (pure alexia for Kana from a posterior occipital gyri lesion) suggested that pure alexia could be divided into two types, i.e. ventromedial type in which whole-word reading, together with letter identification, is primarily impaired because of a disconnection of word-form images from early visual analysis, and posterior type in which letter identification is cardinally impaired. Another type of alexia, alexia with agraphia for Kanji from a posterior inferior temporal cortex lesion (patient 3), results from deficient whole-word images of words per se, and thus should be designated “orthographic alexia with agraphia”. To account for these impairments, a weighted dual-route hypothesis for reading is suggested. PMID:15201492

  11. Time reversal communication system

    DOEpatents

    Candy, James V.; Meyer, Alan W.

    2008-12-02

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

  12. Reversible Chemochromic Hydrogen Detectors

    NASA Technical Reports Server (NTRS)

    2008-01-01

    The Florida Solar Energy Center (FSEC), affiliated with the University of Central Florida, has invented a reversible pigment that changes from light beige to blue when exposed to hydrogen and back to light beige when exposed to atmospheric oxygen. In laboratory and environmental studies, the FSEC pigment in its tape form failed to change color adequately when exposed to hydrogen after one day of exposure at Kennedy Space Center's Beach Corrosion Test Facility. The reversible hydrogen-detecting tape also lost its ability to change color after being placed in an environmental chamber at 45 C for one day. The first attempts at extruding the reversible pigment into various polymers were unsuccessful because of the pigment's poor thermal stability. The goal of this project was to formulate a pigment with improved thermal and environmental stability for extrusion into a variety of appropriate polymer matrices. The formulation of the reversible hydrogen-detecting pigment was modified by removing one reagent and chemically modifying the hydrogen sensitive ingredient. This was intended to improve the hydrophobicity of the pigment and alter the thermal degradation mechanism.

  13. Engineering Encounters: Reverse Engineering

    ERIC Educational Resources Information Center

    McGowan, Veronica Cassone; Ventura, Marcia; Bell, Philip

    2017-01-01

    This column presents ideas and techniques to enhance your science teaching. This month's issue shares information on how students' everyday experiences can support science learning through engineering design. In this article, the authors outline a reverse-engineering model of instruction and describe one example of how it looked in our fifth-grade…

  14. Reversing Discrimination: A Perspective

    ERIC Educational Resources Information Center

    Pati, Gopal; Reilly, Charles W.

    1977-01-01

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

  15. Reversing Flow Test Facility

    NASA Astrophysics Data System (ADS)

    Roach, P. D.

    1986-04-01

    The Reversing Flow Test Facility (RFTF) is intended for the study of fluid flow and heat transfer under the reversing-flow conditions that occur in Stirling engines. The facility consists of four major parts: (1) Mechanical Drive - two cylinders with cam-driven pistons which generate the reversing gas flow, (2) Test Section - a U-shaped section containing instrumented test pieces, (3) Instruments -l high-speed transducers for measuring gas pressure and temperature, piston positions, and other system parameters, and (4) Data Acquisition System - a computer-based system able to acquire, store, display and analyze the data from the instruments. The RFTF can operate at pressures up to 8.0 MPa, hot-side temperatures to 800 deg. C, and flow-reversal frequencies to 50 Hz. Operation to data has used helium as the working gas at pressures of 3.0 and 6.0 MPa, at ambient temperature, and at frequencies from 1 to 50 Hz. The results show that both frictional and inertial parts of the pressure drop are significant in the heater, coolers and connecting tubes; the inertial part is negligible in the regenerators. In all cases, the frictional part of the pressure drop is nearly in phase with the mass flow.

  16. Reversible cerebral vasoconstriction syndrome.

    PubMed

    Lee, R; Ramadan, H; Bamford, J

    2013-01-01

    Reversible cerebral vasoconstriction syndrome (RCVS) is an underdiagnosed condition which usually presents as severe headache with or without neurological deficit. We report the case of a 55-year-old woman who presented with headache and multifocal intracerebral haemorrhage. We review the literature regarding the presentation, pathophysiology and management of RCVS and discuss how to differentiate it from cerebral vasculitis.

  17. Language Reversion Revisited.

    ERIC Educational Resources Information Center

    De Bot, Kees; Clyne, Michael

    1989-01-01

    A longitudinal study on language maintenance and loss among Dutch-English bilinguals in Australia revealed little loss in both languages over the years. This leads to the hypothesis of a "critical threshold" that must be reached to retain the second language. First language reversion appears commonly among immigrants who did not reach this…

  18. Reverse homeosis in homeotically reconstructed ribbonworms

    PubMed Central

    Tarpin, Michel; Gehring, Walter J.; Bièrne, Jacques

    1999-01-01

    Homeosis is the replacement of one body part by another, which may be caused by either developmental or genetic variations. It is particularly obvious in segmented animals, like insects, in which one body segment may be transformed into another. However, homeosis also occurs in animals without overt segmentation that also have detailed positional information specifying their body plan. By grafting, we have artificially generated homeotic ribbonworms of the species Lineus ruber with a duplicated ocellar region replacing the postocellar region anterior to the brain. Such chimeric animals are capable of complete morphogenetic regulation of the anterior–posterior (A–P) pattern. The missing postocellar region is restored by intercalary regeneration, and the anterior duplicated ocellar region is eliminated by a process called transgeneration. Thus, homeosis is reversed, and a completely normal pattern along the A–P axis is restored. This reverse homeosis involves the elimination of the syngeneic eyes and the survival of the grafted allogeneic eye region. LsPax-6, the Lineus sanguineus ortholog of the mammalian Pax-6 gene, which is considered to be a master control gene for eye morphogenesis, is expressed specifically in regenerating, regenerated, and intact eye regions. Our data show that ribbonworm eyes are either maintained or they regress according to their position along the A–P axis, even though there are no obvious segmental boundaries. This system allows us to test the function of LsPax-6 protein not only during eye regeneration but also during maintenance and regression of the eyes. PMID:10518548

  19. Posterior reperfusion T-waves: Wellens' syndrome of the posterior wall.

    PubMed

    Driver, Brian E; Shroff, Gautam R; Smith, Stephen W

    2017-02-01

    Reperfusion after coronary occlusion (myocardial infarction, MI), as in Wellens' syndrome, is often represented on ECG as T-wave inversion in the leads overlying the affected myocardial wall(s). As an extension of this logic, reperfusion of the posterior wall should manifest on right precordial leads (which are opposite the posterior wall) as enlarged T-waves. We sought to determine whether T-wave amplitude (TWa) in leads V2 and V3 after reperfusion in posterior MI (PMI) is greater than in patients without PMI. Review of ECGs from patients with ST elevation MI of the left circumflex or right coronary artery with post-procedure thrombolysis in MI (TIMI) flow >0 between 2007 and 2009. Blinded experts reviewed admission ECGs to determine the presence of PMI and measure TWa before and after reperfusion. Maximum TWa in V2 and V3 and the difference between maximum and admission V2 and V3 TWa were compared between those with and without PMI. Of 72 patients, 48 had PMI. Values expressed are medians and IQRs. Maximum TWa after reperfusion was greater in PMI than in non-PMI in V2 (5.00 mm (3.5 to 8.25) vs 3.9 mm (2.75 to 5.5), p=0.04), but not in V3 (4.0 mm (2 to 5.5) vs 3.0 mm (1.75 to 4), p=0.09). The increase in TWa in V2 and V3 after reperfusion was greater in PMI compared with non-PMI: (V2, 3.4 mm (2 to 5.25) vs 1.25 mm (-0.25 to 2), p=0.0005; V3, 2 mm (-0.5 to 3.25) vs 0.25 mm (-1 to 1.75), p=0.03). Reperfusion of the posterior wall results in higher right precordial TWa, and an even greater increase in TWa, as measured in leads V2 and V3. This observation has important implications for emergency physicians to accurately identify recent posterior infarction in patients who may be symptom free on presentation but at risk of reocclusion. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  20. Posterior regeneration in Isodiametra pulchra (Acoela, Acoelomorpha)

    PubMed Central

    2013-01-01

    Introduction Regeneration is a widespread phenomenon in the animal kingdom, but the capacity to restore damaged or missing tissue varies greatly between different phyla and even within the same phylum. However, the distantly related Acoelomorpha and Platyhelminthes share a strikingly similar stem-cell system and regenerative capacity. Therefore, comparing the underlying mechanisms in these two phyla paves the way for an increased understanding of the evolution of this developmental process. To date, Isodiametra pulchra is the most promising candidate as a model for the Acoelomorpha, as it reproduces steadily under laboratory conditions and is amenable to various techniques, including the silencing of gene expression by RNAi. In order to provide an essential framework for future studies, we report the succession of regeneration events via the use of cytochemical, histological and microscopy techniques, and specify the total number of cells in adult individuals. Results Isodiametra pulchra is not capable of regenerating a new head, but completely restores all posterior structures within 10 days. Following amputation, the wound closes via the contraction of local muscle fibres and an extension of the dorsal epidermis. Subsequently, stem cells and differentiating cells invade the wound area and form a loosely delimited blastema. After two days, the posterior end is re-patterned with the male (and occasionally the female) genital primordium being apparent. Successively, these primordia differentiate into complete copulatory organs. The size of the body and also of the male and female copulatory organs, as well as the distance between the copulatory organs, progressively increase and by nine days copulation is possible. Adult individuals with an average length of 670 μm consist of approximately 8100 cells. Conclusion Isodiametra pulchra regenerates through a combination of morphallactic and epimorphic processes. Existing structures are “re-modelled” and provide a

  1. Paratrooper's ankle fracture: posterior malleolar fracture.

    PubMed

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

    2015-03-01

    We assessed the frequency and types of ankle fractures that frequently occur during parachute landings of special operation unit personnel and analyzed the causes. 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. 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. Posterior malleolar fractures occurred in 41.07% of ankle fractures sustained in parachute landings. Because most of the ankle fractures in parachute injuries were compound fractures, most cases had to

  2. 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

  3. Association between breast-feeding duration and posterior crossbites.

    PubMed

    Limeira, Adriana Bezerra; Aguiar, Carlos Menezes; de Lima Bezerra, Niedje Siqueira; Câmara, Andréea Cruz

    2014-01-01

    The purpose of this study was to evaluate the association between breast-feeding duration and the subsequent occurrence of posterior crossbite in Brazilian children. A cross-sectional study was conducted involving 714 six- to nine-year-old children. A questionnaire was completed by mothers or guardians of the children concerning the length of time they were exclusively breast-fed and the breast-feeding duration. A clinical examination of each child was conducted to detect posterior crossbite. Data were analyzed using Pearson's chi-square test at a five percent significance level. There was a posterior crossbite prevalence of approximately 15 percent. There was no statistically significant association between posterior crossbite and age or gender ( P >.05). The prevalence of posterior crossbite was higher among children who were not breast-fed (28 percent) than among breast-fed children (13 percent). There was a significant association between posterior crossbite and the length of time that children were exclusively breast-fed and the breast-feeding duration ( P <.05 percent). The prevalence of posterior crossbite gradually decreased as exclusive breast-feeding duration increased, and there was a relationship between breast-feeding duration and the occurrence of posterior crossbite.

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

    PubMed

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

    2015-01-16

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

  5. Radial head fracture associated with posterior interosseous nerve injury.

    PubMed

    Terra, Bernardo Barcellos; Sassine, Tannus Jorge; Lima, Guilherme de Freitas; Rodrigues, Leandro Marano; Padua, David Victoria Hoffmann; Nadai, Anderson de

    2016-01-01

    Fractures of the radial head and radial neck correspond to 1.7-5.4% of all fractures and approximately 30% may present associated injuries. In the literature, there are few reports of radial head fracture with posterior interosseous nerve injury. This study aimed to report a case of radial head fracture associated with posterior interosseous nerve injury.

  6. Posterior scleritis with retinal pigment epithelium rip: an unusual presentation.

    PubMed

    Fiebai, Bassey; Padhi, Tapas Ranjan; Panda, Krushna Gopal; Modi, Rohit Ramesh

    2015-02-01

    Posterior scleritis is a great mimicker and can cause irreversible visual loss because of late or misdiagnosis. We report a case of retinal pigment epithelial rip in the event of nodular posterior scleritis that is hardly reported in the literature. The authors hypothesize the rip to be a result of inflammation, exudation and continuing pressure by the fluid or granuloma on the pigment epithelium.

  7. Posterior distributions for likelihood ratios in forensic science.

    PubMed

    van den Hout, Ardo; Alberink, Ivo

    2016-09-01

    Evaluation of evidence in forensic science is discussed using posterior distributions for likelihood ratios. Instead of eliminating the uncertainty by integrating (Bayes factor) or by conditioning on parameter values, uncertainty in the likelihood ratio is retained by parameter uncertainty derived from posterior distributions. A posterior distribution for a likelihood ratio can be summarised by the median and credible intervals. Using the posterior mean of the distribution is not recommended. An analysis of forensic data for body height estimation is undertaken. The posterior likelihood approach has been criticised both theoretically and with respect to applicability. This paper addresses the latter and illustrates an interesting application area. Copyright © 2016 The Chartered Society of Forensic Sciences. Published by Elsevier Ireland Ltd. All rights reserved.

  8. Rare Posterior Pharyngeal Mass: Atypical Marginal Zone Hyperplasia.

    PubMed

    Eliçora, Sultan Şevik; Güven, Mehmet; Varli, Ali F; Yilmaz, Mahmut S; Alponat, Selin

    2016-03-01

    Cases of posterior pharyngeal masses are quite rare, and are typically derived from schwannoma or encephalocele, or are of vascular or infectious origin. They are clinically significant due to their tendency to cause airway obstruction. The aim of this study was to present a rare atypical marginal hyperplasia case of a posterior pharyngeal wall mass. A 10-year-old male was admitted to our clinic with dyspnea. A plane-surfaced 4 × 3 × 3 cm mass was observed on the posterior pharyngeal wall upon physical examination. The patient underwent magnetic resonance imaging and surgical treatment. Following excision of material from the patient's mass, a pathologic diagnosis of atypical marginal zone hyperplasia was made. Atypical marginal zone hyperplasia of the posterior pharyngeal wall has not yet been reported in the literature. Marginal zone hyperplasia associated with a lymphoproliferative disease should be considered when making differential diagnoses of posterior pharyngeal wall masses.

  9. Wnt signaling and the evolution of embryonic posterior development.

    PubMed

    Martin, Benjamin L; Kimelman, David

    2009-03-10

    During vertebrate embryogenesis, most of the mesodermal tissue posterior to the head forms from a progenitor population that continuously adds blocks of muscles (the somites) from the back end of the embryo. Recent work in less commonly studied arthropods--the flour beetle Tribolium and the common house spider--provides evidence suggesting that this posterior growth process might be evolutionarily conserved, with canonical Wnt signaling playing a key role in vertebrates and invertebrates. We discuss these findings as well as other evidence that suggests that the genetic network controlling posterior growth was already present in the last common ancestor of the Bilateria. We also highlight other interesting commonalities as well as differences between posterior growth in vertebrates and invertebrates, suggest future areas of research, and hypothesize that posterior growth may facilitate evolution of animal body plans.

  10. The Posterior Unstable Shoulder: Natural History, Clinical Evaluation and Imaging

    PubMed Central

    Díaz Heredia, Jorge; Ruiz Iban, Miguel Angel; Ruiz Diaz, Raquel; Moros Marco, Santos; Gutierrez Hernandez, Juan Carlos; Valencia, Maria

    2017-01-01

    Background: There is a low incidence of posterior instability which is present in only 2% to 10% of all unstable shoulders. The posterior instable shoulder includes different manifestations like fixed dislocation, recurrent subluxation or dislocation. Methods: Research and online content related to posterior instability is reviewed. Natural history, clinical evaluation and imaging are described. Results: An awareness of the disorder, together with a thoughtful evaluation, beginning with the clinical history, usually leads to proper diagnosis. An appropriate physical exam, taking in account hyperlaxity and specific tests for posterior instability should be done. Conclusion: Posterior shoulder instability is an uncommon condition and is challenging to diagnose. There is not a single injury that is responsible for all cases of recurrent shoulder dislocation or subluxation, and the presence of soft tissue lesions or bone alterations should be evaluated, with the use of adequate simple radiology and multiplanar imaging.

  11. Management of the posterior capsule during pediatric intraocular lens implantation.

    PubMed

    Buckley, E G; Klombers, L A; Seaber, J H; Scalise-Gordy, A; Minzter, R

    1993-06-15

    One of the major obstacles in pediatric intraocular lens implantation has been the subsequent dense opacification of the posterior capsule. We used a modification of the standard pediatric cataract surgical procedure, which involved endocapsular cataract extraction, posterior chamber intraocular lens implantation, pars plana posterior capsulotomy, and pars plana anterior vitrectomy in 20 consecutive patients with unilateral traumatic, radiation-induced, and developmental cataracts. Visual axes were rapidly restored in all patients without further intervention for posterior capsule opacification. Visual acuity returned to 20/40 or better in all patients and 75% of all patients (15 patients) reached maximum improvement by five weeks. No complications attributed to intraoperative removal of the posterior capsule occurred.

  12. Posterior population expansion for solving inverse problems

    NASA Astrophysics Data System (ADS)

    Jäggli, C.; Straubhaar, J.; Renard, P.

    2017-04-01

    Solving inverse problems in a complex, geologically realistic, and discrete model space and from a sparse set of observations is a very challenging task. Extensive exploration by Markov chain Monte Carlo (McMC) methods often results in considerable computational efforts. Most optimization methods, on the other hand, are limited to linear (continuous) model spaces and the minimization of an objective function, what often proves to be insufficient. To overcome these problems, we propose a new ensemble-based exploration scheme for geostatistical prior models generated by a multiple-point statistics (MPS) tool. The principle of our method is to expand an existing set of models by using posterior facies information for conditioning new MPS realizations. The algorithm is independent of the physical parametrization. It is tested on a simple synthetic inverse problem. When compared to two existing McMC methods (iterative spatial resampling (ISR) and Interrupted Markov chain Monte Carlo (IMcMC)), the required number of forward model runs was divided by a factor of 8-12.

  13. The cognitive profile of posterior cortical atrophy.

    PubMed

    McMonagle, Paul; Deering, Fiona; Berliner, Yaniv; Kertesz, Andrew

    2006-02-14

    Posterior cortical atrophy (PCA) is a progressive dementia characterized by prominent disorders of higher visual processing, affecting both dorsal and ventral streams to cause Balint's syndrome, alexia, and visual agnosia. To define the cognitive profile of PCA and compare to the typical, primary amnestic dementia of the Alzheimer's type (DAT). The authors used standard cognitive tests and a novel battery designed to reflect dysfunction in both ventral (Object, Face & Color Agnosia Screen [OFCAS]) and dorsal (complex pictures and compound stimuli) visual streams. The authors identified 19 patients with PCA and compared their performance to a matched group of patients with DAT and normal controls. Patients with PCA were younger with marked impairment in visuospatial tasks, reading, and writing but relative preservation of memory compared to DAT using standard tests. Dorsal stream signs were most prevalent among the patients with PCA with no pure ventral stream syndromes found. All novel tests distinguished reliably between subjects with complex picture descriptions and processing of compound stimuli showing the most significant differences compared to DAT. PCA is predominantly a dorsal stream syndrome, distinct from typical DAT, which involves occipitotemporal regions over time.

  14. 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

  15. Management of Atraumatic Posterior Interosseous Nerve Palsy.

    PubMed

    Sigamoney, Kohila Vani; Rashid, Abbas; Ng, Chye Yew

    2017-10-01

    The posterior interosseous nerve (PIN) is susceptible to a number of traumatic and atraumatic pathologies. In this article, we aim to review our current understanding of the etiology, pathology, diagnosis, treatment options, and published outcomes of atraumatic PIN palsy. In general, the etiology of atraumatic PIN palsy can be divided into mechanical, which is caused by an extrinsic compressive force on the nerve, and nonmechanical, which is caused by an intrinsic inflammatory reaction within the nerve. As per this discussion, there are 3 causes for atraumatic PIN palsy. These are entrapment neuropathy, Parsonage-Turner syndrome, and spontaneous "hourglass" constriction. The typical presentation of atraumatic PIN palsy is a patient with spontaneous onset of weakness of fingers/thumb metacarpophalangeal joints extension. However, the wrist extension is preserved with radial deviation due to preservation of extensor carpi radialis longus/brevis function. Magnetic resonance imaging is the imaging of choice and neurophysiology is indicated in all patients. If there is an obvious structural cause of the nerve palsy, prompt decompression and removal of the causative lesion are recommended to avoid irreversible damage to the nerve/muscles. Otherwise, in general, we would recommend consideration for exploration should there be no sign of recovery after 6 weeks of observation. Copyright © 2017 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  16. Representation of numerosity in posterior parietal cortex

    PubMed Central

    Roitman, Jamie D.; Brannon, Elizabeth M.; Platt, Michael L.

    2012-01-01

    Humans and animals appear to share a similar representation of number as an analog magnitude on an internal, subjective scale. Neurological and neurophysiological data suggest that posterior parietal cortex (PPC) is a critical component of the circuits that form the basis of numerical abilities in humans. Patients with parietal lesions are impaired in their ability to access the deep meaning of numbers. Acalculiac patients with inferior parietal damage often have difficulty performing arithmetic (2 + 4?) or number bisection (what is between 3 and 5?) tasks, but are able to recite multiplication tables and read or write numerals. Functional imaging studies of neurologically intact humans performing subtraction, number comparison, and non-verbal magnitude comparison tasks show activity in areas within the intraparietal sulcus (IPS). Taken together, clinical cases and imaging studies support a critical role for parietal cortex in the mental manipulation of numerical quantities. Further, responses of single PPC neurons in non-human primates are sensitive to the numerosity of visual stimuli independent of low-level stimulus qualities. When monkeys are trained to make explicit judgments about the numerical value of such stimuli, PPC neurons encode their cardinal numerical value; without such training PPC neurons appear to encode numerical magnitude in an analog fashion. Here we suggest that the spatial and integrative properties of PPC neurons contribute to their critical role in numerical cognition. PMID:22666194

  17. Dynamic properties of the posterior cricoarytenoid muscle.

    PubMed

    Cooper, D S; Shindo, M; Sinha, U; Hast, M H; Rice, D H

    1994-12-01

    The aim of this research was to investigate the contractile properties of the posterior cricoarytenoid (PCA) muscle. Simultaneous measurements were made of the isometric force, temperature, and electromyographic activity of the dorsal cricoarytenoid muscle of anesthetized dogs during supramaximal stimulation of the recurrent laryngeal nerve for twitch and tetanic contraction. The conduction delay between stimulation of the recurrent nerve at the level of the larynx and the onset of the muscle action potential averaged 2.0 +/- 0.2 milliseconds (ms), and the latent period between the onset of electrical activity of the muscle and the onset of contraction had a mean duration of 3.3 +/- 0.8 ms. The mean of isometric contraction times found was 33.3 +/- 2.0 ms, shorter than most previous studies of canine PCA muscle. Tetanic frequency defined as smooth contraction was higher than previous estimates. Considerations of scaling of physiological time based on animal mass were applied to analysis of the experimental findings to make possible systematic comparison of previous findings across species and animal size.

  18. New infectious etiologies for posterior uveitis.

    PubMed

    Khairallah, Moncef; Kahloun, Rim; Ben Yahia, Salim; Jelliti, Bechir; Messaoud, Riadh

    2013-01-01

    Emergent and resurgent arthropod vector-borne diseases are major causes of systemic morbidity and death and expanding worldwide. Among them, viral and bacterial agents including West Nile virus, Dengue fever, Chikungunya, Rift Valley fever, and rickettsioses have been recently associated with an array of ocular manifestations. These include anterior uveitis, retinitis, chorioretinitis, retinal vasculitis and optic nerve involvement. Proper clinical diagnosis of any of these infectious diseases is based on epidemiological data, history, systemic symptoms and signs, and the pattern of ocular involvement. The diagnosis is usually confirmed by the detection of a specific antibody in serum. Ocular involvement associated with emergent infections usually has a self-limited course, but it can result in persistent visual impairment. There is currently no proven specific treatment for arboviral diseases, and therapy is mostly supportive. Vaccination for humans against these viruses is still in the research phase. Doxycycline is the treatment of choice for rickettsial diseases. Prevention, including public measures to reduce the number of mosquitoes and personal protection, remains the mainstay for arthropod vector disease control. Influenza A (H1N1) virus was responsible for a pandemic human influenza in 2009, and was recently associated with various posterior segment changes.

  19. Posterior capsule opacification. Part 1: Experimental investigations.

    PubMed

    Nishi, O

    1999-01-01

    Posterior capsule opacification (PCO) is the most frequent complication associated with decreased vision after cataract surgery. Previous methods of preventing PCO have not proven to be practical, effective, and safe for routine clinical procedure, but some novel concepts and methods have recently been developed. This 2-part review looks at clinical and experimental investigations of PCO, focusing on developments since 1992. Clinical aspects will be presented in a later issue. This paper addresses (1) in vitro models for PCO research; (2) pathophysiology and molecular biology of lens epithelial cells (LECs); (3) prevention of PCO. Of special interest are methods of culturing human LECs obtained by capsulotomy during cataract surgery, including those obtained with an intact capsular bag, to provide an in vitro model for investigating the pathophysiology of LECs; the effect of a sharp bend in the lens capsule that induces contact inhibition of migrating LECs; more specific inhibition of migrating LECs using an immunotoxin, b-FGF-saporin, or EDTA and RGD-peptides.

  20. 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.

  1. "Apperceptive" alexia in posterior cortical atrophy.

    PubMed

    Mendez, Mario F; Shapira, Jill S; Clark, David G

    2007-02-01

    The most common presenting complaint in posterior cortical atrophy (PCA) is reading difficulty. Although often described as an alexia without agraphia, alexia in PCA may have multiple causes, including a primary visuoperceptual etiology, attentional alexia, and central reading difficulty. This study evaluated 14 patients with early PCA and disturbances in reading ability in comparison to 14 normal controls. All 14 patients had a progressive disorder of complex visual functions and neuroimaging evidence of occipitoparietal dysfunction. They underwent a task requiring identification of single letters with and without flanking distractors. They also read single words consisting of regular English spelling or irregular grapheme-phoneme correspondence (irregular words) and pronounceable nonsense words (pseudowords). The PCA patients made errors in letter identification when letters were flanked by visually similar letters or numbers. They could read most single regular and irregular words but made visual errors and had particular trouble with pseudowords. They could not use a letter-by-letter reading strategy effectively. The PCA patients had similar difficulties on other visuoperceptual tests. These findings are consistent with an alexia manifested by perceptual and attentional difficulty on attempting serial visual processing of letters in the context of other letters. This "apperceptive alexia" results when the configuration of letters into words is impaired during letter-by-letter reading. Disproportionate difficulty reading pseudowords suggests an additional impairment in phonological processing. PCA patients have variable neuropathology and individual patients may have other contributions to their reading impairment.

  2. Ganglion cysts of the posterior cruciate ligament.

    PubMed

    Shetty, Gautam M; Nha, Kyung Wook; Patil, Sachin P; Chae, Dong Ju; Kang, Ki Hoon; Yoon, Jung Ro; Choo, Suk Kyu; Yi, Jeong Woo; Kim, Ji Hoon; Baek, Jong Ryoon

    2008-08-01

    Ganglion cysts of the posterior cruciate ligament (PCL) are uncommon lesions found incidentally on MRI and arthroscopy. Twenty patients (11 males and nine females) with the mean age of 35 years presenting with a variety of knee signs and symptoms were found to have PCL cysts on MRI. Out of these, thirteen patients (65%) had isolated symptomatic PCL cysts and seven patients had associated chondral and meniscal lesions. Eight out of the 20 patients (40%) gave a history of antecedent trauma. On arthroscopy, the majority of the cysts were situated at the midsubstance of the ligament with inter-cruciate distension and no involvement of the substance of the ligament. The content of the cysts varied with the majority having yellowish viscous fluid and three containing serous and bloody fluid. All cysts were successfully treated arthroscopically through standard anterior, posteromedial and posterolateral portals with no signs of recurrence on MRI at a mean followup of 24 months. PCL cysts may clinically mimic meniscal or chondral lesions and preoperatively, MRI is essential for the diagnosis of ganglion cysts arising from the PCL. Ganglion cysts of the PCL can be successfully treated arthroscopically using standard portals.

  3. Logopenic syndrome in posterior cortical atrophy.

    PubMed

    Magnin, Eloi; Sylvestre, Geraldine; Lenoir, Flora; Dariel, Elfried; Bonnet, Louise; Chopard, Gilles; Tio, Gregory; Hidalgo, Julie; Ferreira, Sabrina; Mertz, Catherine; Binetruy, Mikael; Chamard, Ludivine; Haffen, Sophie; Ryff, Ilham; Laurent, Eric; Moulin, Thierry; Vandel, Pierre; Rumbach, Lucien

    2013-02-01

    Few language disorders have been reported in posterior cortical atrophy (PCA). Furthermore, no study has focused on screening for them and described these language deficits. The goal of this work was to describe linguistic examination of PCA patients and the impact of language disorders on neuropsychological performances compared to patients with other neurodegenerative syndromes and control groups. Linguistic examination of 9 PCA patients was carried out. The neuropsychological performance of the PCA group (16 patients) in the RAPID battery tests was compared with performances of patients with a logopenic variant of primary progressive aphasia (LPPA), patients with Alzheimer's disease and patients with amnestic mild cognitive impairment, as well as the control group. A "logopenic syndrome" with anomia, fluency impairment, and length-dependent deficit was found in 8/9 PCA patients. A comparison with other neurodegenerative syndromes showed that not only visual disorders but also language and verbal short-term memory disorders, such as those found in LPPA, can explain neuropsychological performances. A "logopenic syndrome" is frequently found in PCA and may be associated with poor performance on other verbally mediated neuropsychological tasks (e.g., verbal memory). Specific logopedic rehabilitation should be offered to these patients.

  4. ABC classification of posterior shoulder instability.

    PubMed

    Moroder, Philipp; Scheibel, Markus

    2017-01-01

    Posterior glenohumeral instability (PGHI) is a commonly under- and misdiagnosed pathology owing to its variety of clinical presentations. In order to facilitate diagnosis and treatment, the simple yet comprehensive ABC classification for PGHI is based on the underlying pathomechanical principles and current standard of treatment. Three main groups of PGHI are distinguished based on the type of instability: A (first time), B (dynamic), C (static). Two subtypes further differentiate these groups in terms of their specific pathomechanism and provide a guideline in the choice of appropriate treatment: A (1, subluxation; 2, dislocation), B (1, functional; 2, structural), C (1, constitutional; 2, acquired). While conservative treatment is warranted in most patients with type 1 PGHI (A1, B1, C1), surgical treatment should be considered on an individual basis in patients with type 2 PGHI (A2, B2, C2), while keeping in mind that the different groups and subtypes can overlap, co-exist, or even progress from one to another over time. Of course the necessity for surgical treatment depends on the extent of the structural defects, on the severity of symptoms, on the chronicity, as well as on patient-specific functional demand, age, and health status. Nonetheless, the ABC classification helps to correctly diagnose the type of PGHI and provides a guideline for the generally recommended type of treatment.

  5. Posterior Probability Matching and Human Perceptual Decision Making.

    PubMed

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

    2015-06-01

    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

  6. Mitral Valve Mechanics Following Posterior Leaflet Patch Augmentation

    PubMed Central

    Rahmani, Azadeh; Rasmussen, Ann Q.; Honge, Jesper L.; Ostli, Bjorn; Levine, Robert A.; Hagège, Albert; Nygaard, Hans; Nielsen, Sten L.; Jensen, Morten O.

    2013-01-01

    Background and aim of the study Attention towards the optimization of mitral valve repair methods is increasing. Patch augmentation is one strategy used to treat functional ischemic mitral regurgitation (FIMR). The study aim was to investigate the force balance changes in specific chordae tendineae emanating from the posterior papillary muscle in a FIMR-simulated valve, following posterior leaflet patch augmentation. Methods Mitral valves were obtained from 12 pigs (body weight 80 kg). An in vitro test set-up simulating the left ventricle was used to hold the valves. The left ventricular pressure was regulated with water to simulate different static pressures during valve closure. A standardized oval pericardial patch (17 × 29 mm) was introduced into the posterior leaflet from mid P2 to the end of the P3 scallop. Dedicated miniature transducers were used to record the forces exerted on the chordae tendineae. Data were acquired before and after 12 mm posterior and 5 mm apical posterior papillary muscle displacement to simulate the effect from one of the main contributors of FIMR, before and after patch augmentation. Results The effect of displacing the posterior papillary muscle induced tethering on the intermediate chordae tendineae to the posterior leaflet, and resulted in a 39.8% force increase (p = 0.014). Posterior leaflet patch augmentation of the FIMR valve induced a 31.1% force decrease (p = 0.007). There was no difference in force between the healthy and the repaired valve simulations (p = 0.773). Conclusion Posterior leaflet patch augmentation significantly reduced the forces exerted on the intermediate chordae tendineae from the posterior papillary muscle following FIMR simulation. As changes in chordal tension lead to a redistribution of the total stress exerted on the valve, patch augmentation may have an adverse long-term influence on mitral valve function and remodeling. PMID:23610985

  7. 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

  8. A reverse transcriptase ribozyme.

    PubMed

    Joyce, Gerald F; Samanta, Biswajit

    2017-09-26

    A highly evolved RNA polymerase ribozyme was found to also be capable of functioning as a reverse transcriptase, an activity that has never been demonstrated before for RNA. This activity is thought to have been crucial for the transition from RNA to DNA genomes during the early history of life on Earth, when it similarly could have arisen as a secondary function of an RNA-dependent RNA polymerase. The reverse transcriptase ribozyme can incorporate all four dNTPs and can generate products containing up to 32 deoxynucleotides. It is likely that this activity could be improved through evolution, ultimately enabling the synthesis of complete DNA genomes. DNA is much more stable compared to RNA and thus provides a larger and more secure repository for genetic information.

  9. Gridded electron reversal ionizer

    NASA Technical Reports Server (NTRS)

    Chutjian, Ara (Inventor)

    1993-01-01

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

  10. Reversible Aggregation of Albumin

    NASA Astrophysics Data System (ADS)

    Colby, Ralph H.; Oates, Katherine M. N.; Krause, Wendy E.; Jones, Ronald L.

    2004-03-01

    We explore the interactions in synovial fluid involving the polyelectrolyte sodium hyaluronate (NaHA) and plasma proteins in their native state (albumin and globulins). Rheological measurements on synovial fluid show it to be highly viscoelastic and also rheopectic (stress increases with time in steady shear). Equilibrium dialysis confirms the findings of Ogston and Dubin that there is no association between NaHA and albumin at physiological pH and salt. What we find instead is a reversible aggregation of albumin, with an association energy of order 3kT and commensurate association lifetime of order microseconds. Certain anti-inflammatory drugs are shown to prevent this reversible aggregation. The implications of these findings for synovial fluid and blood rheology are discussed.

  11. Reversible Cerebral Vasoconstriction Syndrome: Recognition and Treatment.

    PubMed

    Cappelen-Smith, Cecilia; Calic, Zeljka; Cordato, Dennis

    2017-06-01

    Reversible cerebral vasoconstriction syndrome (RCVS) is a rare but increasingly recognized disorder with over 500 cases published in the literature. The condition is characterized by recurrent severe thunderclap headaches with or without other neurological symptoms and diffuse segmental narrowing of the cerebral arteries which is reversible within 3 months. RCVS may occur spontaneously but in over 50% of cases, it is associated with various other conditions, including vasoactive medications or illicit drugs and the post-partum state. One third to a half of cases develop hemorrhagic or ischemic brain lesions or a combination of both. Posterior reversible encephalopathy syndrome (PRES) often occurs in association with RCVS and the conditions are likely to share a common pathophysiology. The pathogenesis of RCVS remains uncertain but autonomic dysregulation, oxidative stress, and genetic predisposition are postulated. Significant differential diagnoses include subarachnoid hemorrhage (SAH) due to aneurysmal rupture, cervical artery dissection, and primary angiitis of the central nervous system (PACNS). Although there is no proven treatment, calcium channel antagonists including nimodipine and verapamil have been administered with reported reduction of headache intensity but without effect on the time course of cerebral vasoconstriction. Glucocorticoids have been reported as an independent predictor of worse outcome and should be avoided. The cornerstone of RCVS management remains largely supportive with bed rest and analgesics and removal of precipitating factors. Invasive neurointerventional techniques should be reserved for severe deteriorating cases. The condition is usually benign and self-limited and the majority of patients have a favorable outcome but around 5-10% are left with permanent neurological deficits and rare cases may die. This review details the importance of the early recognition of this increasingly described condition and current treatment

  12. Reversing Glass Wettability

    NASA Technical Reports Server (NTRS)

    Frazier, D. O.; Smith, J. E., Jr.; Kaukler, W. F.

    1985-01-01

    Treatment reverses wettability of glassware: Liquids that normally wet glass no longer do, and those that do not wet glass are made to do so. Useful in research on container effects in nucleation and growth of secondary phase from solution. Treatment consists of spreading 3 percent (by weight) solution of silicone oil in hexane isomers over glass, drying in air, and curing at 300 degrees C in vacuum for one hour.

  13. URCHIN: Reverse ray tracer

    NASA Astrophysics Data System (ADS)

    Altay, Gabriel; Theuns, Tom

    2014-12-01

    URCHIN is a Smoothed Particle Hydrodynamics (SPH) reverse ray tracer (i.e. from particles to sources). It calculates the amount of shielding from a uniform background that each particle experiences. Preservation of the adaptive density field resolution present in many gas dynamics codes and uniform sampling of gas resolution elements with rays are two of the benefits of URCHIN; it also offers preservation of Galilean invariance, high spectral resolution, and preservation of the standard uniform UV background in optically thin gas.

  14. [Reversible cerebral vasoconstriction syndrome].

    PubMed

    Laakso, Elina; Pekkola, Johanna; Soinne, Lauri; Putaala, Jukka

    2014-01-01

    Reversible cerebral vasoconstriction syndrome (RCVS) is increasingly recognized. The condition is characterized by multifocal vasoconstriction lesions in cerebral arteries. Headache is the central symptom, with an acute onset and paroxysmal occurrence. Some of the patients develop intracranial hemorrhage, ischemic disturbance of the cerebral circulation, hypertensive encephalopathy (PRES) or epileptic seizures as complications. The disease is most common in middle-aged women. Most patients have an underlying predisposing factor, most commonly vasoactive medications, drugs or puerperium. There is no evidence-based practice.

  15. 49 CFR 230.89 - Reverse gear.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

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

  16. 49 CFR 230.89 - Reverse gear.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

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

  17. 49 CFR 230.89 - Reverse gear.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

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

  18. 49 CFR 230.89 - Reverse gear.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

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

  19. 49 CFR 230.89 - Reverse gear.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

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

  20. Time reversal interactive objects

    NASA Astrophysics Data System (ADS)

    Ing, Ros Ki; Quieffin, Nicolas; Catheline, Stefan; Fink, Mathias

    2001-05-01

    Time reversal has shown to be a fruitful concept in nondestructive testing in underwater acoustic or in ultrasonic imaging. In this paper this technique is adapted in the audible range to transform every day objects into tactile sensitive interfaces. A quick historical background is presented in the ultrasonic field and specially in chaotic cavity. In all time reversal experiments, it is demonstrated that a wave field spatially and temporally recorded is able to back propagate to its source. In other words, the field contains all the information on the location of the source. In the interactive experiments, it is shown that touching an object like a window, a table or a world globe generates an acoustic field easily detectable with one or two acoustic sensors. Using the concept of time reversal, the source location is deduced in real time. Then, touching objects at specific locations (virtual switches) is used to activate devices. Such devices are for example lights, stereo volume, or computer software. From a technical point of view, all these interactive experiments just use some computation easily performed with a standard personnel computer.

  1. Reversible hysteresis loop tuning

    NASA Astrophysics Data System (ADS)

    Berger, A.; Binek, Ch.; Margulies, D. T.; Moser, A.; Fullerton, E. E.

    2006-02-01

    We utilize antiferromagnetically coupled bilayer structures to magnetically tune hysteresis loop properties. Key element of this approach is the non-overlapping switching field distribution of the two magnetic layers that make up the system: a hard magnetic CoPtCrB layer (HL) and a soft magnetic CoCr layer (SL). Both layers are coupled antiferromagnetically through an only 0.6-nm-thick Ru interlayer. The non-overlapping switching field distribution allows the measurement of magnetization reversal in the SL at low fields while keeping the magnetization state of the HL unperturbed. Applying an appropriate high field or high field sequence changes the magnetic state of the HL, which then influences the SL magnetization reversal due to the interlayer coupling. In this way, the position and shape of the SL hysteresis loop can be changed or tuned in a fully reversible and highly effective manner. Here, we study specifically how the SL hysteresis loop characteristics change as we move the HL through an entire high field hysteresis loop sequence.

  2. Posterior ankle impingement syndrome caused by malunion of joint depressed type calcaneal fracture.

    PubMed

    Lui, T H

    2008-07-01

    Late complications after calcaneal fracture usually resulted in lateral heel pain. Malunion of joint depressed type calcaneal fracture can result in posterior ankle impingement pain. This is caused by the posterior calcaneal bone spike formed just behind the posterior calcaneal facet. We describe a technique to resect the offending posterior calcaneal bone spike to relieve the posterior ankle impingement pain.

  3. Origin of subcortical somatosensory evoked potentials in response to posterior tibial nerve stimulation in humans.

    PubMed

    Urasaki, E; Wada, S; Yokota, A; Tokimura, T; Yasukouchi, H

    1993-06-01

    To identify the origin of short latency somatosensory evoked potentials (SSEPs) to posterior tibial nerve stimulation, direct recordings were made from the cervical cord, the ventricular system and the frontal subcortex during 8 neurosurgical operations. The origin of each component of SSEPs was also studied in 7 selected patients with various lesions in the central nervous system. In addition, SSEPs to median nerve stimulation were investigated in 4 of 8 surgical cases and all 7 cases of the lesion study group. Bilateral posterior tibial nerve stimulation in 10 normal subjects showed spinal N28 on the skin of the posterior neck and far-field P30 and N33 components followed by a cortical P38 component at the scalp. Direct recordings made to the mid-brain through the medulla oblongata showed a negative potential with gradually increasing latency. The peak of the negativity in the vicinity of the dorsal column nucleus showed almost the same latency as that of the scalp far-field P30, and positivity with a stationary peak was found above the dorsal column nucleus. Above the mid-pons, there was a stationary negativity with no latency shift, showing the same peak latency as that of scalp N33. The spatiotemporal distributions of P30 and N33 to posterior tibial nerve stimulation were analogous to those of P14 and N18 by median nerve stimulation. Transesophageal and direct cervical cord recordings showed that the spinal N13 phase to median nerve stimulation was reversed between the dorsal and ventral sides of the cervical cord. No such reversal occurred for the spinal N28 potential. Clinical lesion studies showed that changes in P30 and P14, and in N33 and N18 correlated with one another: that is, 1) prolongation of latency of N33 was also observed for N18; 2) absence of P30 was paralleled by the absence of P14. These data suggest that spinal N28 originates from ascending activity such as a dorsal column volley, and scalp P30 comes from activity near the dorsal column

  4. Posterior urethral valves and adult sexual function.

    PubMed

    Taskinen, Seppo; Heikkilä, Jukka; Santtila, Pekka; Rintala, Risto

    2012-10-01

    To evaluate sexual function and fertility in adult patients treated for posterior urethral valves (PUV) in childhood and to compare these patients with the normal population. To examine if patient characteristics such as chronic renal failure (CRF), history of cryptorchidism and bladder neck incision in childhood have an impact on sexual function. Information on sexual function was assessed using questions from the International Index of Erectile Function (IIEF). In addition, the patients were asked if they had had children or been treated for CRF. Out of 108 adult patients with PUV, 67 (62%) returned the questionnaires. Sexual function in these patients was compared with 201 controls and paternity rates were compared with a national database. The mean (sd) age of the patients and controls was 38 (9) and 38 (7) years, respectively. Six percent of the patients and 9% of the controls reported problems in achieving erection during sexual stimulation and 9% of the patients and 10% of the controls reported problems with the hardness of erection (P = nonsignificant). Ejaculation was absent in 1/61 sexually active patients (2%). The only significant risk factor in patients for erectile dysfunction (ED) was increasing age. Thirty-three (49%) of all 67 patients and four (57%) of the seven patients with kidney transplantation had had children. The paternity rates were similar to those in corresponding age groups of the general Finnish population. Eight patients (12%) had attempted to have children without success. Men treated for PUV have a similar prevalence of ED and similar paternity rates to men without PUV. Erectile function and paternity rates can be satisfactory in spite of CRF. © 2012 THE AUTHORS. BJU INTERNATIONAL © 2012 BJU INTERNATIONAL.

  5. The language profile of Posterior Cortical Atrophy

    PubMed Central

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

    2015-01-01

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

  6. Posterior spinal fusion using pedicle screws.

    PubMed

    Athanasakopoulos, Michael; Mavrogenis, Andreas F; Triantafyllopoulos, George; Koufos, Spiros; Pneumaticos, Spiros G

    2013-07-01

    Few clinical studies have reported polyetheretherketone (PEEK) rod pedicle screw spinal instrumentation systems (CD-Horizon Legacy PEEK rods; Medtronic, Minneapolis, Minnesota). This article describes a clinical series of 52 patients who underwent posterior spinal fusion using the PEEK Rod System between 2007 and 2010. Of the 52 patients, 25 had degenerative disk disease, 10 had lateral recess stenosis, 6 had degenerative spondylolisthesis, 6 had lumbar spine vertebral fracture, 4 had combined lateral recess stenosis and degenerative spondylolisthesis, and 1 had an L5 giant cell tumor. Ten patients had 1-segment fusion, 29 had 2-segment fusion, and 13 had 3-segment fusion. Mean follow-up was 3 years (range, 1.5-4 years); no patient was lost to follow-up. Clinical evaluation was performed using the Oswestry Disability Index and a low back and leg visual analog pain scale. Imaging evaluation of fusion was performed with standard and dynamic radiographs. Complications were recorded. Mean Oswestry Disability Index scores improved from 76% preoperatively (range, 52%-90%) to 48% at 6 weeks postoperatively, and to 34%, 28%, and 30% at 3, 6, and 12 months postoperatively, respectively. Mean low back and leg pain improved from 8 and 9 points preoperatively, respectively, to 6 and 5 points immediately postoperatively, respectively, and to 2 points each thereafter. Imaging union of the arthrodesis was observed in 50 (96%) patients by 1-year follow-up. Two patients sustained screw breakage: 1 had painful loss of sagittal alignment of the lumbar spine and underwent revision spinal surgery with pedicle screws and titanium rods and the other had superficial wound infection and was treated with wound dressing changes and antibiotics for 6 weeks. No adjacent segment degeneration was observed in any patient until the time of this writing. Copyright 2013, SLACK Incorporated.

  7. Posterior urethral valves: long-term outcome.

    PubMed

    Caione, Paolo; Nappo, Simona Gerocarni

    2011-10-01

    Posterior urethral valves represent the most common cause of bladder outlet obstruction in infancy that impairs renal and bladder function. Long-term outcome of patients with previous PUV is evaluated. Patients over 18 years of age, treated from 1982 to 1995 before the age of 3 years were considered. Previous surgery, renal function, bladder activity, urinary incontinence, and fertility/sexual activity were evaluated. Clinical interview, creatinine clearance, uroflowmetry with ultrasound post-void urine residue, and self-administered questionnaire were recorded. Out of 45 identified records, 24 patients (53.3%) accepted to be enrolled (age 18-34 years, mean 23 years). The mean follow-up was 19.5 years (16-30 years). Out of the 21 excluded patients, 20 did not reply to the clinical interview and 1 died at age of 6 years. All the 24 patients had early endoscopic section of PUV; nine also received transient ureterocutaneostomy or vesicostomy. Ureteroneocystostomy was performed in five patients and ureterocystoplasty with unilateral nephrectomy in two. At follow-up chronic renal failure was detected in 13 patients (54.1%) and 9 (37.5%) had arterial hypertension. End-stage renal disease developed in five patients (20.8%): three had successful renal transplantation and two were in dialysis. Lower urinary tract symptoms were present in seven patients (29.1%). No significant fertility deficit and sexual dysfunction were observed in 23 patients, while 1 patient was azoospermic. No paternity was reported so far. Long-term outcome of patients with previously treated PUV is mandatory. Kidney, bladder, and sexual functions should be monitored till adulthood to verify any modified behaviour.

  8. Finite element analysis of posterior cervical fixation.

    PubMed

    Duan, Y; Wang, H H; Jin, A M; Zhang, L; Min, S X; Liu, C L; Qiu, S J; Shu, X Q

    2015-02-01

    Despite largely, used in the past, biomechanical test, to investigate the fixation techniques of subaxial cervical spine, information is lacking about the internal structural response to external loading. It is not yet clear which technique represents the best choice and whether stabilization devices can be efficient and beneficial for three-column injuries (TCI). The different posterior cervical fixation techniques (pedicle screw PS, lateral mass screw LS, and transarticular screw TS) have respective indications. A detailed, geometrically accurate, nonlinear C3-C7 finite element model (FEM) had been successfully developed and validated. Then three FEMs were reconstructed from different fixation techniques after C4-C6 TCI. A compressive preload of 74N combined with a pure moment of 1.8 Nm in flexion, extension, left-right lateral bending, and left-right axial rotation was applied to the FEMs. The ROM results showed that there were obvious significant differences when comparing the different fixation techniques. PS and TS techniques can provide better immediate stabilization, compared to LS technique. The stress results showed that the variability of von Mises stress in the TS fixation device was minimum and LS fixation device was maximum. Furthermore, the screws inserted by TS technique had high stress concentration at the middle part of the screws. Screw inserted by PS and LS techniques had higher stress concentration at the actual cap-rod-screw interface. The research considers that spinal surgeon should first consider using the TS technique to treat cervical TCI. If PS technique is used, we should eventually prolong the need for external bracing in order to reduce the higher risk of fracture on fixation devices. If LS technique is used, we should add anterior cervical operation for acquire a better immediate stabilization. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  9. Aspheric versus Spherical Posterior Chamber Intraocular Lenses

    PubMed Central

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

    2010-01-01

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

  10. Posterior ankle impingement syndrome: A systematic four-stage approach

    PubMed Central

    Yasui, Youichi; Hannon, Charles P; Hurley, Eoghan; Kennedy, John G

    2016-01-01

    Posterior ankle impingement syndrome (PAIS) is a common injury in athletes engaging in repetitive plantarflexion, particularly ballet dancers and soccer players. Despite the increase in popularity of the posterior two-portal hindfoot approach, concerns with the technique remain, including; the technical difficulty, relatively steep learning curve, and difficulty performing simultaneous anterior ankle arthroscopy. The purpose of the current literature review is to provide comprehensive knowledge about PAIS, and to describe a systematic four-stage approach of the posterior two-portal arthroscopy. The etiology, clinical presentation, diagnostic strategies are first introduced followed by options in conservative and surgical management. A detailed systematic approach to posterior hindfoot arthroscopy is then described. This technique allows for systematic review of the anatomic structures and treatment of the bony and/or soft tissue lesions in four regions of interest in the hindfoot (superolateral, superomedial, inferomedial, and inferolateral). The review then discusses biological adjuncts and postoperative rehabilitation and ends with a discussion on the most recent clinical outcomes after posterior hindfoot arthroscopy for PAIS. Although clinical evidence suggests high success rates following posterior hindfoot arthroscopy in the short- and mid-term it may be limited in the pathology that can be addressed due to the technical skills required, but the systematic four-stage approach of the posterior two-portal arthroscopy may improve upon this problem. PMID:27795947

  11. Neural correlates of cognitive impairment in posterior cortical atrophy.

    PubMed

    Kas, Aurélie; de Souza, Leonardo Cruz; Samri, Dalila; Bartolomeo, Paolo; Lacomblez, Lucette; Kalafat, Michel; Migliaccio, Raffaella; Thiebaut de Schotten, Michel; Cohen, Laurent; Dubois, Bruno; Habert, Marie-Odile; Sarazin, Marie

    2011-05-01

    With the prospect of disease-modifying drugs that will target the physiopathological process of Alzheimer's disease, it is now crucial to increase the understanding of the atypical focal presentations of Alzheimer's disease, such as posterior cortical atrophy. This study aimed to (i) characterize the brain perfusion profile in posterior cortical atrophy using regions of interest and a voxel-based approach; (ii) study the influence of the disease duration on the clinical and imaging profiles; and (iii) explore the correlations between brain perfusion and cognitive deficits. Thirty-nine patients with posterior cortical atrophy underwent a specific battery of neuropsychological tests, mainly targeting visuospatial functions, and a brain perfusion scintigraphy with 99mTc-ethyl cysteinate dimer. The imaging analysis included a comparison with a group of 24 patients with Alzheimer's disease, matched for age, disease duration and Mini-Mental State Examination, and 24 healthy controls. The single-photon emission computed tomography profile in patients with posterior cortical atrophy was characterized by extensive and severe hypoperfusion in the occipital, parietal, posterior temporal cortices and in a smaller cortical area corresponding to the frontal eye fields (Brodmann areas 6/8). Compared with patients with Alzheimer's disease, the group with posterior cortical atrophy showed more severe occipitoparietal hypoperfusion and higher perfusion in the frontal, anterior cingulate and mesiotemporal regions. When considering the disease duration, the functional changes began and remained centred on the posterior lobes, even in the late stage. Correlation analyses of brain perfusion and neuropsychological scores in posterior cortical atrophy highlighted the prominent role of left inferior parietal damage in acalculia, Gerstmann's syndrome, left-right indistinction and limb apraxia, whereas damage to the bilateral dorsal occipitoparietal regions appeared to be involved in B

  12. In vivo measurements of humeral movement during posterior glenohumeral mobilizations.

    PubMed

    Talbott And, Nancy R; Witt, Dexter W

    2016-12-01

    The purpose of this study was to quantify in vivo posterior translational movements occurring in the glenohumeral joint during posterior mobilizations and to determine the intratester reliability of those posterior translational movements. Twenty-eight individuals (17 females, 11 males) participated in this study. One physical therapist utilized a Kaltenborn approach to apply three grades of posterior humeral mobilization. A hand held dynamometer was used to quantify the force used during each grade of mobilization. Ultrasound imaging was used to visualize and measure posterior humeral movement. Statistical analysis included descriptive statistics for force and posterior movement, intraclass correlation coefficient (ICC) for intrarater reliability of force and posterior movement during each grade of mobilization and paired t-tests to compare movement and force between grades of mobilization. Mean posterior movement (mm) measurements were 3.0, 8.2 and 10.7 for grade I, grade II and grade III mobilizations, respectively. Mean force (Newtons) measurements used during mobilization were 41.7, 121.5 and 209.4 for grade I, grade II and grade III mobilizations, respectively. The ICCs ranged from 0.849 to 0.905 for movement and from 0.717 to 0.889 for force. Force and measurement values were significantly different between grades of mobilization and between dominant and non-dominant arms. Gender was found to be significantly associated with force. Mean movements and mean forces occurring during posterior mobilization increased with increasing grades. Intratester reliability was high for all grades of manual mobilization supporting the use of subjective feedback to determine appropriate force application. Quantification of forces and movements helps to clarify parameters that can serve as a reference for clinical practice.

  13. Incidence and surgical importance of the posterior gastric artery.

    PubMed Central

    Suzuki, K; Prates, J C; DiDio, L J

    1978-01-01

    In a series of 61 adult cadavers, the posterior gastric artery was found in 38 (62.3%), originating from the superior aspect of the mid-third of the splenic artery. The posterior gastric artery, running behind the parietal peritoneum of the omental bursa, produced a peritoneal fold before reaching the posterior wall of the superior portion of the gastric body, near the cardiac region, and the fundus. Its high incidence, hidden origin, deep course, and distribution make this artery very important for surgical procedures relating to the stomach, pancreas, spleen, and celiac region. It may be crucial, especially if partial gastric resection of splenectomy have obliterated other gastric vessels. PMID:629615

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

    PubMed Central

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

    2015-01-01

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

  15. Posterior cortical atrophy: an atypical variant of Alzheimer disease.

    PubMed

    Suárez-González, Aida; Henley, Susie M; Walton, Jill; Crutch, Sebastian J

    2015-06-01

    Posterior cortical atrophy (PCA) is a neurodegenerative syndrome characterized by striking progressive visual impairment and a pattern of atrophy mainly involving posterior cortices. PCA is the most frequent atypical presentation of Alzheimer disease. The purpose of this article is to provide a summary of PCA's neuropsychiatric manifestations. Emotional and psychotic symptoms are discussed in the context of signal characteristic features of the PCA syndrome (the early onset, focal loss of visual perception, focal posterior brain atrophy) and the underlying cause of the disease. The authors' experience with psychotherapeutic intervention and PCA support groups is shared in detail.

  16. Ossification of the posterior longitudinal ligament: a case report

    PubMed Central

    Aker, PD; O’Connor, SM; Mior, SA; Beauchemin, D

    1989-01-01

    Ossification of the posterior longitudinal ligament (OPLL) has recently been recognized as a clinical entity. It is a rare condition, having a higher incidence in the Japanese population. It is characterized by hyperplasia of cartilage cells with eventual endochondral ossification of the posterior longitudinal ligament. The radiographic signs are characteristic and consist of a linear band of ossified tissue along the posterior margin of the vertebral body. OPLL can be associated with mild to serious neurological complications due to spinal cord or nerve root compression, or it may be asymptomatic. This paper reviews the radiological, clinical and therapeutic aspects of this rare condition. ImagesFigures 1 and 2Figures 3 and 4

  17. Immunopathology of the noninfectious posterior and intermediate uveitides.

    PubMed

    Boyd, S R; Young, S; Lightman, S

    2001-01-01

    The posterior and intermediate uveitides share an underlying immune etiology; however, they can be clinically and immunopathologically distinguished. Although the initiating stimuli for posterior and intermediate uveities are not known, it is believed that an exogenous agent (such as a bacterium or a virus) or an endogenous molecule may induce disease. In either case, T-helper lymphocytes in conjunction with human leukocyte antigens are likely to be involved. This review examines the epidemiology, histology, immunopathology, and theories of pathogenesis of several posterior and intermediate uveitides, including sympathetic ophthalmia, Vogt-Koyanagi-Harada syndrome, Behçet's disease, sarcoidosis, intermediate uveitis, white dot syndromes, and birdshot retinochoroidopathy.

  18. Asystole during posterior fossa surgery: Report of two cases

    PubMed Central

    Goyal, Keshav; Philip, Frenny Ann; Rath, Girija Prasad; Mahajan, Charu; Sujatha, M.; Bharti, Sachidanand Jee; Gupta, Nidhi

    2012-01-01

    Asystole during posterior fossa neurosurgical procedures is not uncommon. Various causes have been implicated, especially when surgical manipulation is carried out in the vicinity of the brain stem. The trigemino-cardiac reflex has been attributed as one of the causes. Here, we report two cases who suffered asystole during the resection of posterior fossa tumors. The vago-glossopharyngeal reflex and the direct stimulation of the brainstem were hypothesized as the causes of asytole. These episodes resolved spontaneously following withdrawal of the surgical stimulus emphasizing the importance of anticipation and vigilance during critical moments of tumor dissection during posterior fossa surgery. PMID:22870159

  19. Posterior Wall Blowout in Anterior Cruciate Ligament Reconstruction

    PubMed Central

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

    2016-01-01

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

  20. [A Case of Juvenile Cerebral Infarction due to Reversible Cerebral Vasoconstriction Syndrome].

    PubMed

    Koh, Masaki; Tsuboi, Yoshifumi; Fukuda, Osamu

    2016-11-01

    A 19-year-old woman had a thunderclap headache, followed by left hemiparesis and left homonymous hemianopsia. Laboratory tests showed no signs of infection and immunological test results were unremarkable. MRI revealed a cerebral infarction in the right posterior cerebral artery territory, and digital subtraction angiography(DSA)showed right posterior cerebral artery stenosis on day 2. The first follow-up DSA demonstrated an irregular, bead-like appearance on day 9, but the stenotic lesion returned to normal on day 21. Reversible cerebral vasoconstriction syndrome should be suspected in cases of rapid resolution of symptoms.

  1. Reversible brazing process

    SciTech Connect

    Pierce, J.D.; Stephens, J.J.; Walker, C.A.

    1999-09-14

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

  2. Reversible brazing process

    DOEpatents

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

    1999-01-01

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

  3. Reversal bending fatigue testing

    DOEpatents

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

    2014-10-21

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

  4. Magnetic source imaging in posterior cortex epilepsies.

    PubMed

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

    2015-01-01

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

  5. Minimally invasive percutaneous posterior lumbar interbody fusion.

    PubMed

    Khoo, Larry T; Palmer, Sylvain; Laich, Daniel T; Fessler, Richard G

    2002-11-01

    The wide exposure required for a standard posterior lumbar interbody fusion (PLIF) can cause unnecessary trauma to the lumbar musculoligamentous complex. By combining existing microendoscopic, percutaneous instrumentation and interbody technologies, a novel, minimally invasive, percutaneous PLIF technique was developed to minimize such iatrogenic tissue injury (MIP-PLIF). The MIP-PLIF technique was validated in three cadaveric torsos with six motion segments decompressed and fused. Preoperative variables measured from imaging included interpedicular distance, pedicular height and width, interspinous distance, lordosis, intervertebral height, Cobb angle, and foraminal height and volume. Using the METRx and MD spinal access systems (Medtronic Sofamor Danek, Memphis, TN), bilateral laminotomies were performed using a hybrid of microsurgical and microendoscopic techniques. The intervertebral disc spaces were then distracted and prepared with the Tangent (Medtronic Sofamor Danek) interbody instruments. Either a 10 or 12 by 22 mm interbody graft was then placed. Using the Sextant (Medtronic Sofamor Danek) system, percutaneous pedicle screw-rod fixation of the motion segment was completed. We then applied MIP-PLIF in three patients. For segments with preoperative intervertebral/foraminal height loss, MIP-PLIF was effective in restoring both heights in all cases. The amount of improvement (9.7 to 38% disc height increase; 7.7 to 29.9% foraminal height increase) varied directly with the size of the graft used and the original degree of disc and foraminal height loss. Segmental lordosis improved by 29% on average. Graft and screw placement was accurate in the cadavers, except for a single Grade 1 screw violation of one pedicle. The average operative time was 3.5 hours per level. In our three clinical cases, the MIP-PLIF procedure required a mean of 5.4 hours, estimated blood loss was 185 ml, and inpatient stay was 2.8 days, with no intravenous narcotic use after 2 days in

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

    PubMed

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

    2013-04-01

    Reversible cerebral vasoconstriction syndrome (RCVS) is a clinicoradiological diagnosis comprising 'thunderclap' headaches and reversible segmental vasoconstriction of cerebral arteries, occasionally complicated by ischaemic or haemorrhagic stroke. We report a case of RCVS in a 13-year-old male with severe thunderclap headaches and no focal neurological signs. Brain imaging showed multiple posterior circulation infarcts; cerebral computed tomography, magnetic resonance imaging, and catheter angiography showed multifocal irregularity and narrowing, but in different arterial segments. Laboratory studies did not support a diagnosis of vasculitis. Symptoms resolved over 3 weeks; magnetic resonance angiography 3 months later was normal and remained so after 2 years. We highlight the typical clinical features of RCVS in this case and suggest that the diagnosis should be considered in children with thunderclap headaches or stroke syndromes where headache is a prominent feature, especially if cerebrovascular imaging studies appear to be evolving or discrepant. © The Authors. Developmental Medicine & Child Neurology © 2012 Mac Keith Press.

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

    PubMed

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

    2016-01-01

    Reduced posterior tibial slope (PTS) and posterior tibiofemoral translation (PTFT) in posterior cruciate-retaining (PCR) total knee arthroplasty (TKA) may result in suboptimal flexion. We evaluated the relationship between PTS, PTFT, and total knee flexion after PCR TKA in a cadaveric model. We performed a balanced PCR TKA using 9 transfemoral cadaver specimens and changed postoperative PTS in 1° increments. We measured maximal flexion and relative PTFT at maximal flexion. We determined significant changes in flexion and PTFT as a function of PTS. Findings showed an average increase in flexion of 2.3° and average PTFT increase of 1mm per degree of PTS increase when increasing PTS from 1° to 4° (P<.05). Small initial increases in PTS appear to significantly increase knee flexion and PTFT. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Reversal of sterilisation.

    PubMed

    Cartwright, A

    1977-09-03

    It is difficult to know what conclusions one can reach in a study of 103 women who asked for reversal of sterilization (Mr. R.M.L. Winston, July 30, p. 305) when there are no data about the numbers and characteristics of the women who were sterilized and have not asked for reversal. And Mr. Winston's conclusion that it "seems unwise to sterilise women under 30 particularly immediately after pregnancy or if their marriage is in jeopardy" is therefore difficult to justify and has a disconcertingly paternalistic ring. It also implies that the stability or otherwise of a marriage should be a prime concern of obstetricians when women request sterilization. But what distrubed me most about Mr. Winston's article was his statement that "most women in this survey had been told that termination would not be undertaken without sterilisation." I wonder if this form of ultimatum, which Mr. Winston condemns, is likely to increase now that this operation is performed under a fee-for-service system?

  9. Reverse Engineering Molecular Hypergraphs

    PubMed Central

    Rahman, Ahsanur; Poirel, Christopher L.; Badger, David J.; Estep, Craig; Murali, T.M.

    2014-01-01

    Analysis of molecular interaction networks is pervasive in systems biology. This research relies almost entirely on graphs for modeling interactions. However, edges in graphs cannot represent multiway interactions among molecules, which occur very often within cells. Hypergraphs may be better representations for networks having such interactions, since hyperedges can naturally represent relationships among multiple molecules. Here, we propose using hypergraphs to capture the uncertainty inherent in reverse engineering gene-gene networks. Some subsets of nodes may induce highly varying subgraphs across an ensemble of networks inferred by a reverse engineering algorithm. We provide a novel formulation of hyperedges to capture this uncertainty in network topology. We propose a clustering-based approach to discover hyperedges. We show that our approach can recover hyperedges planted in synthetic data sets with high precision and recall, even for moderate amount of noise. We apply our techniques to a data set of pathways inferred from genetic interaction data in S. cerevisiae related to the unfolded protein response. Our approach discovers several hyperedges that capture the uncertain connectivity of genes in relevant protein complexes, suggesting that further experiments may be required to precisely discern their interaction patterns. We also show that these complexes are not discovered by an algorithm that computes frequent and dense subgraphs. PMID:24384702

  10. Reverse engineering molecular hypergraphs.

    PubMed

    Rahman, Ahsanur; Poirel, Christopher L; Badger, David J; Estep, Craig; Murali, T M

    2013-01-01

    Analysis of molecular interaction networks is pervasive in systems biology. This research relies almost entirely on graphs for modeling interactions. However, edges in graphs cannot represent multiway interactions among molecules, which occur very often within cells. Hypergraphs may be better representations for networks having such interactions, since hyperedges can naturally represent relationships among multiple molecules. Here, we propose using hypergraphs to capture the uncertainty inherent in reverse engineering gene-gene networks. Some subsets of nodes may induce highly varying subgraphs across an ensemble of networks inferred by a reverse engineering algorithm. We provide a novel formulation of hyperedges to capture this uncertainty in network topology. We propose a clustering-based approach to discover hyperedges. We show that our approach can recover hyperedges planted in synthetic data sets with high precision and recall, even for moderate amount of noise. We apply our techniques to a data set of pathways inferred from genetic interaction data in S. cerevisiae related to the unfolded protein response. Our approach discovers several hyperedges that capture the uncertain connectivity of genes in relevant protein complexes, suggesting that further experiments may be required to precisely discern their interaction patterns. We also show that these complexes are not discovered by an algorithm that computes frequent and dense subgraphs.

  11. Reversible cerebral vasoconstriction syndrome.

    PubMed

    Ducros, Anne

    2012-10-01

    Recurrent thunderclap headaches, seizures, strokes, and non-aneurysmal subarachnoid haemorrhage can all reveal reversible cerebral vasoconstriction syndrome. This increasingly recognised syndrome is characterised by severe headaches, with or without other symptoms, and segmental constriction of cerebral arteries that resolves within 3 months. Reversible cerebral vasoconstriction syndrome is supposedly due to a transient disturbance in the control of cerebrovascular tone. More than half the cases occur post partum or after exposure to adrenergic or serotonergic drugs. Manifestations have a uniphasic course, and vary from pure cephalalgic forms to rare catastrophic forms associated with several haemorrhagic and ischaemic strokes, brain oedema, and death. Diagnosis can be hampered by the dynamic nature of clinicoradiological features. Stroke can occur a few days after initial normal imaging, and cerebral vasoconstriction is at a maximum on angiograms 2-3 weeks after clinical onset. The calcium channel blocker nimodipine seems to reduce thunderclap headaches within 48 h of administration, but has no proven effect on haemorrhagic and ischaemic complications. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. Rhinocerebral mucormycosis with extension to the posterior fossa: case report.

    PubMed

    Soloniuk, D S; Moreland, D B

    1988-11-01

    A 25-year-old man with juvenile onset diabetes presented with rhinoorbital mucormycosis. He was treated aggressively with orbital extirpation and amphotericin B. Six months later, he presented with posterior fossa extension of the mucormycosis.

  13. Posterior polymorphous corneal dystrophy concomitant to large colloid drusen.

    PubMed

    Del Turco, Claudia; Pierro, Luisa; Querques, Giuseppe; Gagliardi, Marco; Corvi, Federico; Manitto, Maria Pia; Bandello, Francesco M

    2015-01-01

    To describe the previously unreported concomitance of 2 uncommon ocular conditions: posterior polymorphous corneal dystrophy (PPCD) and large colloid drusen (LCD). A 45-year-old woman underwent a complete ophthalmologic examination with slit-lamp biomicroscopy and blue fundus autofluorescence with spectral-domain optical coherence tomography, as well as complete systemic examination and renal function investigation. On slit-lamp biomicroscopy, a corneal lesion located at Descemet membrane was observed in the right eye. The clinical features of deep posterior stromal-endothelial linear bands with vesicles and irregular opacities of posterior corneal surface were consistent with the diagnosis of PPCD. Fundus biomicroscopy and blue fundus autofluorescence showed LCD. We report the unusual coexistence of PPCD and LCD in a young, healthy subject. Posterior polymorphous corneal dystrophy and LCD share morphologic similarities and dysfunctions of collagen architecture in the basement membrane layer, which suggests a possible common pathogenic pathway.

  14. Anterior-Posterior Cerebral Blood Volume Gradient in Human Subiculum

    PubMed Central

    Talati, Pratik; Rane, Swati; Kose, Samet; Gore, John; Heckers, Stephan

    2014-01-01

    The human hippocampal formation is characterized by anterior-posterior gradients of cell density, neurochemistry and hemodynamics. In addition, some functions are associated with specific subfields (subiculum, CA1–4, dentate gyrus) and regions (anterior and posterior). We performed contrast-enhanced, high-resolution T1-weighted 3T steady state (SS) imaging to investigate cerebral blood volume (CBV) gradients of the hippocampal formation. We studied 14 healthy subjects and found significant CBV gradients (anterior > posterior) in the subiculum but not in other hippocampal subfields. Since CBV is a marker of basal metabolism, these results indicate a greater baseline activity in the anterior compared to the posterior subiculum. This gradient might be related to the role of the subiculum as the main outflow station of the hippocampal formation and might have implications for the mechanisms of neuropsychiatric disorders. PMID:24677295

  15. Modified posterior vertebral column resection for Kümmell disease

    PubMed Central

    Liu, Feng-Yu; Huo, Li-Shuang; Liu, Sen; Wang, Hui; Zhang, Li-Jun; Yang, Da-Long; Ding, Wen-Yuan

    2017-01-01

    Abstract Rationale: Kümmell's disease is defined as delayed traumatic vertebral collapse disease in which patients develop a kyphosis after asymptomatic minor spinal trauma. Both anterior approach and posterior approach have been reported, however, there is no standard treatment for Kümmell's disease. Patient concerns: We described a successful modified posterior vertebral column resection in a patient with Kümmell's disease. A 65-year-old woman reported persistent back pain for almost three months. Diagnoses: Kümmell's disease was diagnosed based on computer tomography (CT) and magnetic resonance imaging (MRI). Interventions: Modified posterior vertebral column resection combined with short-segment fixation was designed to treat this disease. Outcomes: The procedure was successful without any complications. Patient reported that symptoms were obviously improved in one week after operation. Lessons: Modified posterior vertebral column resection combined with short-segment fixation is an effective treatment option for Kümmell's disease. PMID:28151882

  16. Resection of Beak-Type Thoracic Ossification of the Posterior Longitudinal Ligament from a Posterior Approach under Intraoperative Neurophysiological Monitoring for Paralysis after Posterior Decompression and Fusion Surgery.

    PubMed

    Imagama, Shiro; Ando, Kei; Ito, Zenya; Kobayashi, Kazuyoshi; Hida, Tetsuro; Ito, Kenyu; Ishikawa, Yoshimoto; Tsushima, Mikito; Matsumoto, Akiyuki; Tanaka, Satoshi; Morozumi, Masayoshi; Machino, Masaaki; Ota, Kyotaro; Nakashima, Hiroaki; Wakao, Norimitsu; Nishida, Yoshihiro; Matsuyama, Yukihiro; Ishiguro, Naoki

    2016-12-01

    Study Design Prospective clinical study. Objective Posterior decompression and fusion surgery for beak-type thoracic ossification of the posterior longitudinal ligament (T-OPLL) generally has a favorable outcome. However, some patients require additional surgery for postoperative severe paralysis, a condition that is inadequately discussed in the literature. The objective of this study was to describe the efficacy of a procedure we refer to as "resection at an anterior site of the spinal cord from a posterior approach" (RASPA) for severely paralyzed patients after posterior decompression and fusion surgery for beak-type T-OPLL. Methods Among 58 consecutive patients who underwent posterior decompression and fusion surgery for beak-type T-OPLL since 1999, 3 with postoperative paralysis (5%) underwent RASPA in our institute. Clinical records, the Japanese Orthopaedic Association score, gait status, intraoperative neurophysiological monitoring (IONM) findings, and complications were evaluated in these cases. Results All three patients experienced a postoperative decline in Manual Muscle Test (MMT) scores of 0 to 2 after the first surgery. RASPA was performed 3 weeks after the first surgery. All patients showed gradual improvements in MMT scores for the lower extremity and in ambulatory status; all could walk with a cane at an average of 4 months following RASPA surgery. There were no postoperative complications. Conclusions RASPA surgery for beak-type T-OPLL after posterior decompression and fusion surgery resulted in good functional outcomes as a salvage surgery for patients with severe paralysis. Advantages of RASPA include a wide working space, no spinal cord retraction, and additional decompression at levels without T-OPLL resection and spinal cord shortening after additional dekyphosis and compression maneuvers. When used with IONM, this procedure may help avoid permanent postoperative paralysis.

  17. Resection of Beak-Type Thoracic Ossification of the Posterior Longitudinal Ligament from a Posterior Approach under Intraoperative Neurophysiological Monitoring for Paralysis after Posterior Decompression and Fusion Surgery

    PubMed Central

    Imagama, Shiro; Ando, Kei; Ito, Zenya; Kobayashi, Kazuyoshi; Hida, Tetsuro; Ito, Kenyu; Ishikawa, Yoshimoto; Tsushima, Mikito; Matsumoto, Akiyuki; Tanaka, Satoshi; Morozumi, Masayoshi; Machino, Masaaki; Ota, Kyotaro; Nakashima, Hiroaki; Wakao, Norimitsu; Nishida, Yoshihiro; Matsuyama, Yukihiro; Ishiguro, Naoki

    2016-01-01

    Study Design Prospective clinical study. Objective Posterior decompression and fusion surgery for beak-type thoracic ossification of the posterior longitudinal ligament (T-OPLL) generally has a favorable outcome. However, some patients require additional surgery for postoperative severe paralysis, a condition that is inadequately discussed in the literature. The objective of this study was to describe the efficacy of a procedure we refer to as “resection at an anterior site of the spinal cord from a posterior approach” (RASPA) for severely paralyzed patients after posterior decompression and fusion surgery for beak-type T-OPLL. Methods Among 58 consecutive patients who underwent posterior decompression and fusion surgery for beak-type T-OPLL since 1999, 3 with postoperative paralysis (5%) underwent RASPA in our institute. Clinical records, the Japanese Orthopaedic Association score, gait status, intraoperative neurophysiological monitoring (IONM) findings, and complications were evaluated in these cases. Results All three patients experienced a postoperative decline in Manual Muscle Test (MMT) scores of 0 to 2 after the first surgery. RASPA was performed 3 weeks after the first surgery. All patients showed gradual improvements in MMT scores for the lower extremity and in ambulatory status; all could walk with a cane at an average of 4 months following RASPA surgery. There were no postoperative complications. Conclusions RASPA surgery for beak-type T-OPLL after posterior decompression and fusion surgery resulted in good functional outcomes as a salvage surgery for patients with severe paralysis. Advantages of RASPA include a wide working space, no spinal cord retraction, and additional decompression at levels without T-OPLL resection and spinal cord shortening after additional dekyphosis and compression maneuvers. When used with IONM, this procedure may help avoid permanent postoperative paralysis. PMID:27853667

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2015-07-01

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

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

    PubMed

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

    2013-12-01

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

  1. Posterior interosseous nerve palsy in a machine gunner.

    PubMed

    Sonna, L A; Scott, B R

    1995-07-01

    We report the case of a 19-year-old Infantryman who developed posterior interosseous nerve palsy and a transient sensory deficit in a radial distribution after prolonged carrying of an M60 machine gun. Posterior interosseous nerve palsy has been reported in association with a variety of activities involving forceful, repetitive pronation and supination; however, to our knowledge, no previous cases of this palsy have been reported in association with use of a military weapon.

  2. An Injectable Method for Posterior Lateral Spine Fusion

    DTIC Science & Technology

    2013-09-01

    reconstruction framework,” Opt. Express 17(19), 16681–16695 (2009). 1. Introduction Spinal fusion is a conventional therapeutic method to reduce pain arising...1 AD_________________ Award Number: W81XWH-12-1-0475 TITLE: An Injectable Method for Posterior... Method for Posterior Lateral Spine Fusion 5b. GRANT NUMBER W81XWH-12-1-0475 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Dr. Elizabeth A

  3. Jerky dystonic shoulder following infarction of the posterior thalamus.

    PubMed

    Walker, Ruth H

    2015-01-01

    The syndrome of the jerky dystonic hand is recognized as a consequence of infarction of the posterior thalamus. A patient with multiple risk factors for stroke developed jerky dystonia of more proximal involvement, affecting the shoulder and speech, several months after a stroke affecting the posterior thalamic region. The cause for the proximal, rather than distal, upper limb involvement, is unclear, and is not apparent from the distribution of the lesion on neuroimaging. Injections of botulinum toxin significantly improved the symptoms.

  4. Posterior polymorphous dystrophy and keratoglobus in a child.

    PubMed

    Patel, Sangita P; Sajnani, Manoj M; Pineda, Roberto

    2011-01-01

    A 13-year-old boy presented with gradually progressive deterioration of vision in both eyes, bilateral photophobia, and regular headaches. Clinical examination, anterior segment findings, and specular microscopy findings were consistent with the diagnosis of posterior polymorphous dystrophy and keratoglobus. To the authors' knowledge, this is the first pediatric case and the second case overall of the simultaneous occurrence of posterior polymorphous dystrophy and keratoglobus.

  5. The influence of posterior occlusion when restoring anterior teeth.

    PubMed

    Reshad, Mamaly; Jivraj, Sajid

    2008-08-01

    When any type of esthetic restorative procedure is being considered or performed, a comprehensive diagnosis and treatment plan is required. Attention to the diagnostic signs of the loss of posterior support (LPS) and their influence on the anterior dentition will guarantee a more predictable outcome. Historical solutions and their inadequacies are addressed. Patient presentations are utilized to demonstrate contemporary treatment of patients requiring esthetic rehabilitations who are lacking posterior support.

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

    PubMed Central

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

    2015-01-01

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

  7. [Tuberculosis of the posterior vertebral arch. A case report].

    PubMed

    Nassar, I; Mahi, M; Semlali, S; Kacemi, L; El Quessar, A; Chakir, N; El Hassani, M R; Jiddane, M

    2002-09-01

    Tuberculosis of the spine usually involves the vertebral body and intervertebral disk. Involvement of the posterior arch is rare. We report a case of tuberculosis involving the posterior elements of the T4 and T5 vertebrae in a 38 year old woman. CT is helpful to assess bony structures whereas MRI is ideal to evaluate the neural structures. Clinical, radiographic, and therapeutic considerations regarding tuberculosis of the spine are reviewed.

  8. Acute Posterior Tarsal Tunnel Syndrome Caused by Gouty Tophus.

    PubMed

    Lui, Tun Hing

    2015-08-01

    Gouty tophus of the tarsal tunnel is a rare cause of posterior tarsal tunnel syndrome. We present a case of acute posterior tarsal tunnel syndrome due to gouty tophus that required early tarsal tunnel release in order to avoid irreversible nerve damage. The presence of background neuropathy resulted in a less favorable result than expected. Therapeutic, Level V: Case report. © 2014 The Author(s).

  9. Comparison of Scheuermann's kyphosis correction by combined anterior-posterior fusion versus posterior-only procedure.

    PubMed

    Etemadifar, Mohammadreza; Ebrahimzadeh, Alireza; Hadi, Abdollah; Feizi, Mehran

    2016-08-01

    Conventional treatment of rigid deformity in Scheuermann's kyphosis (SK) in young patients includes a preliminary anterior spinal release and fusion (ASF) followed by posterior spinal fusion and instrumentation (PSF). However, recently there are more trends to do posterior-only surgery for correction of this deformity. The aim of our study was to compare clinical and radiological outcomes of ASF/PSF and PSF-only procedures in treatment of SK. In a prospective clinical and radiological review, thirty operated SK patients in two groups were evaluated. Group A: ASF/PSF technique (n: 16) and group B: PSF-only procedure (n: 14) were followed for at least 2 years (average 57.6 months). Two groups were well matched for the following four criteria: average age, flexibility status, posterior fusion levels, and preoperative Cobb's kyphosis angle. Oswestry disability index (ODI) and scoliosis research society questionnaire-30 (SRS-30) and radiological (kyphosis correction, correction loss, sagittal balance) parameters were evaluated before and after surgery and at the final follow-up. In group A, primary thoracic Cobb's kyphosis, immediate post-operative kyphosis, and final follow-up kyphosis angle were 83.6°, 41.4° and 43°, respectively (P < 0.05). Correction rate and correction loss were 50.5 % and 1.6° ± 2.4, respectively. In group B, the corresponding values were 81.9°, 40.1° and 43.2°, respectively (P < 0.05). Correction rate and correction loss were 51 % and 3.1° ± 2.5, respectively. SRS-30 and ODI scores in group A were averaged 68.5 and 21.3 preoperatively and 128.7 and 6.25 at the final follow-up, respectively. In group B, the corresponding values were 64 and 23.2 preoperatively and 133.5 and 5.8 at the final follow-up, respectively. Clinical and radiological parameters were similar in both groups after surgical correction while, complication rates, operation time and blood loss were significantly higher in ASF/PSF procedure.

  10. Shoulder arthroplasty for locked posterior dislocation of the shoulder.

    PubMed

    Sperling, John W; Pring, Maya; Antuna, Samuel A; Cofield, Robert H

    2004-01-01

    Currently, there are no published series with mid- to long-term results on patients undergoing shoulder arthroplasty for locked posterior dislocation of the shoulder. We reviewed the results of patients who underwent shoulder arthroplasty for locked posterior dislocation of the shoulder to determine the results, the risk factors for an unsatisfactory outcome, and the rates of failure. Twelve shoulder arthroplasties were performed at our institution, between January 1, 1980, and December 31, 1997, in 12 patients who had a locked posterior dislocation of the shoulder. All 12 patients were followed up for a minimum of 5 years (mean, 9.0 years) or until the time of revision surgery. There was significant pain relief (P <.001) as well as improvement in external rotation from -13 degrees to 28 degrees (P =.001). On the basis of a modified Neer result rating system, there was 1 excellent, 6 satisfactory, and 5 unsatisfactory results. Three patients underwent revision surgery for posterior instability (two) and component loosening (one). Recurrent instability occurred in two patients in the early postoperative period. There were no cases of recurrent instability greater than 1 year from the time of surgery. The data from this study suggest that shoulder arthroplasty for locked posterior dislocation provides pain relief and improved motion. Among those with recurrent posterior instability, it usually appears in the early postoperative period.

  11. Imaging in spinal posterior epidural space lesions: A pictorial essay

    PubMed Central

    Gala, Foram B; Aswani, Yashant

    2016-01-01

    Spinal epidural space is a real anatomic space located outside the dura mater and within the spinal canal extending from foramen magnum to sacrum. Important contents of this space are epidural fat, spinal nerves, epidural veins and arteries. Due to close proximity of posterior epidural space to spinal cord and spinal nerves, the lesions present with symptoms of radiculopathy and/or myelopathy. In this pictorial essay, detailed anatomy of the posterior epidural space, pathologies affecting it along with imaging pearls to accurately diagnose them are discussed. Various pathologies affecting the posterior epidural space either arising from the space itself or occurring secondary to vertebral/intervertebral disc pathologies. Primary spinal bone tumors affecting the posterior epidural space have been excluded. The etiological spectrum affecting the posterior epidural space ranges from degenerative, infective, neoplastic - benign or malignant to miscellaneous pathologies. MRI is the modality of choice in evaluation of these lesions with CT scan mainly helpful in detecting calcification. Due to its excellent soft tissue contrast, Magnetic Resonance Imaging is extremely useful in assessing the pathologies of posterior epidural space, to know their entire extent, characterize them and along with clinical history and laboratory data, arrive at a specific diagnosis and guide the referring clinician. It is important to diagnose these lesions early so as to prevent permanent neurological complication. PMID:27857455

  12. Imaging in spinal posterior epidural space lesions: A pictorial essay.

    PubMed

    Gala, Foram B; Aswani, Yashant

    2016-01-01

    Spinal epidural space is a real anatomic space located outside the dura mater and within the spinal canal extending from foramen magnum to sacrum. Important contents of this space are epidural fat, spinal nerves, epidural veins and arteries. Due to close proximity of posterior epidural space to spinal cord and spinal nerves, the lesions present with symptoms of radiculopathy and/or myelopathy. In this pictorial essay, detailed anatomy of the posterior epidural space, pathologies affecting it along with imaging pearls to accurately diagnose them are discussed. Various pathologies affecting the posterior epidural space either arising from the space itself or occurring secondary to vertebral/intervertebral disc pathologies. Primary spinal bone tumors affecting the posterior epidural space have been excluded. The etiological spectrum affecting the posterior epidural space ranges from degenerative, infective, neoplastic - benign or malignant to miscellaneous pathologies. MRI is the modality of choice in evaluation of these lesions with CT scan mainly helpful in detecting calcification. Due to its excellent soft tissue contrast, Magnetic Resonance Imaging is extremely useful in assessing the pathologies of posterior epidural space, to know their entire extent, characterize them and along with clinical history and laboratory data, arrive at a specific diagnosis and guide the referring clinician. It is important to diagnose these lesions early so as to prevent permanent neurological complication.

  13. Material properties of the human posterior knee capsule.

    PubMed

    Rachmat, H H; Janssen, D; Verkerke, G J; Diercks, R L; Verdonschot, N

    2015-01-01

    There is considerable interest to develop accurate subject-specific biomechanical models of the knee. Most of the existing models currently do not include a representation of the posterior knee capsule. In order to incorporate the posterior capsule in knee models, data is needed on its mechanical properties. To quantify the mechanical properties of the human posterior knee capsule through semi-static tensile tests. Fifteen posterior knee capsule specimens (5 knees, 3 male, 2 female; age 79.2±7.9 years) were used to perform tensile tests. A medial, central and lateral specimen was taken from each knee. The cross-sectional area was measured, after which semi-static tensile tests were performed to quantify the material properties. The stiffness of the capsule was randomly distributed over the regions. The global Young's modulus and yield strength was 8.58±10.77 MPa and 1.75±1.89 MPa, respectively. A strong correlation (ρ=0.900) was found between Young's modulus and yield strength. The location of failure was not associated with smallest cross-sectional area or highest strain. The results suggest that the posterior knee capsule does not have a systematic (medial-central-lateral) distribution of material properties. The posterior capsule may play an important role in knee joint mechanics, particularly when in hyper extension.

  14. Optimizing tooth form with direct posterior composite restorations

    PubMed Central

    Raghu, Ramya; Srinivasan, Raghu

    2011-01-01

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

  15. A new posterior iliac puncture/aspiration needle.

    PubMed

    Islam, Anwarul

    2016-03-25

    The needles that are currently used for obtaining bone marrow aspirate samples from the posterior ilium are typically those of 1930s vintage (eg, Klima, Salah or similar needles), which were specifically designed for sternal aspiration. These needles are not designed to obtain bone marrow aspirate samples from the posterior ilium and as a result they are unsatisfactory particularly if the patient is large or obese. A new posterior iliac puncture/aspiration needle has therefore been designed, which is particularly suited for bone marrow aspiration from the posterior ilium. The needle was tested on five cadavers and on five patients. The design and construction of the needle was found to be satisfactory and a marked improvement over the conventional sternal puncture needles particularly when large or obese patients were concerned. The new posterior iliac bone marrow aspiration needle has advantages that overcome the limitations of using a conventional sternal puncture needle to obtain marrow aspirates from the posterior ilium. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  16. Revision strategy for posterior extrusion of the CHARITÉ polyethylene core.

    PubMed

    Eskander, Mark S; Onyedika, Ikechukwu I; Eskander, Jonathan P; Connolly, Patrick J; Eck, Jason C; Lapinsky, Anthony

    2010-11-15

    This is a case report of a posterior extrusion of the polyethylene core from a CHARITÉ arthroplasty. This is the first reported case of posterior dislocation of the polyethylene and the revision strategies used to correct this problem. To report a novel failure mechanism and revision strategy for CHARITÉ total disc arthroplasty (TDA). Case report at a Level 1 tertiary care referral center in the northeastern United States. This is a case report and review of the literature of a patient who sustained posterior dislocation of the polyethylene core from a CHARITÉ TDA several months after the index procedure. Core dislocation is a known complication of TDA. However, of the known reported dislocations all have been anterior. This case describes the first known occurrence of posterior core dislocation and the revision strategy for this problem. This case report highlights the first known case of a posterior dislocation of a CHARITÉ core. It is likely that altered biomechanical forces generated over time attributed to device failure. An instrumented posterior fusion with removal of the core is what ultimately led to a stable revision construct.

  17. Theta band power increases in the posterior hippocampus predict successful episodic memory encoding in humans.

    PubMed

    Lin, Jui-Jui; Rugg, Michael D; Das, Sandhitsu; Stein, Joel; Rizzuto, Daniel S; Kahana, Michael J; Lega, Bradley C

    2017-10-01

    Functional differences in the anterior and posterior hippocampus during episodic memory processing have not been examined in human electrophysiological data. This is in spite of strong evidence for such differences in rodent data, including greater place cell specificity in the dorsal hippocampus, greater sensitivity to the aversive or motivational content of memories in ventral regions, connectivity analyses identifying preferential ventral hippocampal connections with the amygdala, and gene expression analyses identifying a dorsal-ventral gradient. We asked if memory-related oscillatory patterns observed in human hippocampal recordings, including the gamma band and slow-theta (2.5-5 Hz) subsequent memory effects, would exhibit differences along the longitudinal axis and between hemispheres. We took advantage of a new dataset of stereo electroencephalography patients with simultaneous, robotically targeted anterior, and posterior hippocampal electrodes to directly compare oscillatory subsequent memory effects during item encoding. This same data set allowed us to examine left-right connectivity and hemispheric differences in hippocampal oscillatory patterns. Our data suggest that a power increase during successful item encoding in the 2.5-5 Hz slow-theta frequency range preferentially occurs in the posterior hippocampus during the first 1,000 ms after item presentation, while a gamma band power increase is stronger in the dominant hemisphere. This dominant-nondominant pattern in the gamma range appears to reverse during item retrieval, however. Intrahippocampal phase coherence was found to be stronger during successful item encoding. Our phase coherence data are also consistent with existing reports of a traveling wave for theta oscillations propagating along the septotemporal (longitudinal) axis of the human hippocampus. We examine how our findings fit with theories of functional specialization along the hippocampal axis. © 2017 Wiley Periodicals, Inc.

  18. Ischaemic strokes with reversible vasoconstriction and without thunderclap headache: a variant of the reversible cerebral vasoconstriction syndrome?

    PubMed

    Wolff, Valérie; Armspach, Jean-Paul; Lauer, Valérie; Rouyer, Olivier; Ducros, Anne; Marescaux, Christian; Gény, Bernard

    2015-01-01

    Reversible vasoconstriction (RV) may cause ischaemic stroke (IS) in the absence of any other defined stroke aetiology. The three objectives of our study were to evaluate the frequency of RV in a prospective series of young IS patients, to describe the detailed clinical-radiological features in the patients with RV and IS, and to compare these characteristics with those of reversible cerebral vasoconstriction syndrome (RCVS). We identified between October 2005 and December 2010, 159 consecutive young patients (<45 years) hospitalized for an acute IS confirmed by cerebral magnetic resonance imaging. An extensive diagnostic work-up was performed including toxicological urinary screening for cannabis, cocaine and amphetamines, and the usual biological, cardiac and vascular investigations for an IS in the young. We specifically studied patients with IS and RV, which was defined as multifocal intracranial arterial stenoses confirmed by intracranial arterial imaging that resolved within 3-6 months. Out of 159 patients with IS, 21 (13%, 12 males, 9 females; mean age 32 years) had multifocal cerebral arterial stenoses that were fully reversible at 3-6 months, and no other cause for stroke. IS were located on posterior territory in 71% of cases, and vasoconstriction predominated on posterior cerebral and superior cerebellar arteries. Precipitating factors of IS and RV were the use of cannabis resin (n = 14), nasal decongestants (n = 2) and triptan (n = 1). Most cases (74%) had unusual severe headache, but none had thunderclap headache. None of 21 cases had reversible posterior leukoencephalopathy, cortical subarachnoid or intracerebral haemorrhage. RV was the sole identified cause of IS in 13% of our cohort. These young patients with IS and RV may have a variant of RCVS, related to an increased susceptibility to vasoactive agents in some individuals. RV in our patients differs from the classical characteristics of RCVS by the absence of thunderclap headache, reversible brain

  19. [One-segment interbody lumbar arthrodesis using impacted cages: posterior unilateral approach versus posterior bilateral approach].

    PubMed

    Commarmond, J

    2001-04-01

    We assessed the relative advantages of unilateral versus bilateral posterior approaches for lumbar spine fusion. Eighty-three patients who underwent lumbar spine fusion via a bilateral posterior approach and who had reached more than two years follow-up were compared with 80 patients who had undergone the same procedure via a unilateral posterior approach, including 54 with a follow-up greater than one year and 24 greater than two years. Most cases were L4-L5 fusions for degenerative spondylolisthesis or recurrent discal herniation with instability. Two composite carbon cages were filled with autologous cancellous bone. The key to the unilateral approach was the comfortable exposure of the disc by lamino-arthectomy; the osteosynthesis could then be performed unilaterally if only one gutter was opened. We measured bleeding and operative time to quantify surgical difficulty. At one year we assessed disc height, lordosis, frontal balance, and fusion of the operated disk. At two years, we assessed lombalgia and sciatalgia [scored from 4 (none) to 0 (intolerable)], subjective outcome, and recovery of former activity level. Mean blood loss and operative time were 360 ml and 162 min for the 83 classical procedures and 216 ml and 118 min for the 80 unilateral procedures. There were ten dural wounds with the bilateral approach and one dural wound and one transient radicular deficit with the unilateral approach. At one year, 81 of the 83 unilateral cases had reached fusion (2 nonunions). There was a mean 2 degrees gain in discal lordosis despite three cases of impaction due to osteoporosis. For the unilateral procedures, all 54 reached fusion at one year with a mean 2.5 degrees gain in lordosis, also with 3 impactions. With intersomatic distraction, balanced disc height in the frontal plane was obtained in all cases where the initial narrowing was not excessive. There were no cases of posterior displacement. There was a degradation of the supra-adjacent segment in three of

  20. Precrystalline posterior chamber intraocular lens for surgical correction of severe myopia.

    PubMed

    Barraquer, J

    1999-08-01

    To report early experience with a posterior chamber precrystalline intraocular lens designed for correction of severe myopia from -10 to -30 diopters. This intraocular lens respects the transparent crystalline lens and does not interfere with accommodation. The concave-convex methylmethacrylate lens, with flexible haptics that are supported in the sulcus, is placed behind the iris, in front of the lens, and centered with the pupil. From July 1995 to November 1998, 149 precrystalline lenses have been inserted with few, generally reversible complications, which are now largely prevented by adequate modification of the intraocular lens. Correction has been satisfactory and stable. Although follow-up is relatively short, precrystalline lens placement may be considered an important contribution to the surgical management of severe myopia to improve the patient's vision and, consequently, quality of life.

  1. One step arthroscopically assisted Latarjet and posterior bone-block, for recurrent posterior instability and anterior traumatic dislocation

    PubMed Central

    D’Ambrosi, Riccardo; Perfetti, Carlo; Garavaglia, Guido; Taverna, Ettore

    2015-01-01

    This case presents the challenges of the surgical management for a patient with a history of recurrent posterior shoulder instability and subsequently traumatic anterior dislocation. The patient was already on the waiting list for an arthroscopic posterior stabilization with anchors, when a car accident caused an additional anterior shoulder dislocation. This traumatic anterior dislocation created a bone loss with a glenoid fracture and aggravated the preexisting posterior instability. In order to address both problems, we decided to perform an arthroscopically assisted Latarjet procedure for anterior instability and to stabilize with a bone graft for posterior instability. To our best knowledge, this type of surgical procedure has so far never been reported in the literature. The purpose of this report is to present the surgical technique and to outline the decision making process. PMID:26288539

  2. Pipeline embolization of posterior communicating artery aneurysms associated with a fetal origin posterior cerebral artery.

    PubMed

    Wallace, Adam N; Kayan, Yasha; Austin, Matthew J; Delgado Almandoz, Josser E; Kamran, Mudassar; Cross, DeWitte T; Moran, Christopher J; Osbun, Joshua W; Kansagra, Akash P

    2017-09-01

    Flow diversion may have advantages in the treatment of posterior communicating artery (PComA) aneurysms associated with a fetal origin posterior cerebral artery (PCA), which can be challenging to treat with conventional techniques. However, a PComA incorporated into the aneurysm may prevent or delay aneurysm occlusion. Also, coverage of a fetal origin PCA risks infarction of a large vascular territory. The purpose of this study was to examine the safety and effectiveness of using the Pipeline Embolization Device (PED) to treat PComA aneurysms associated with a fetal origin PCA. Retrospective review of PComA aneurysms associated with a fetal origin PCA treated with the PED at two neurovascular centers was performed. Periprocedural complications and clinical and angiographic outcomes were reviewed. Seven female patients underwent a total of seven PED procedures to treat seven PcomA aneurysms associated with a fetal origin PCA. The symptomatic complication rate was 14% (1/7) per patient and 13% (1/8) per procedure. Angiographic follow up was obtained for 6 of 7 aneurysms. Follow-up DSA at 5-7 months after treatment demonstrated complete occlusion of 17% (1/6) of aneurysms. One aneurysm was retreated with a second PED and occlusion was demonstrated 36 months after the second treatment, yielding an overall complete occlusion rate of 33% (2/6). PED treatment was largely ineffective at treating PComA aneurysms associated with a fetal origin PCA, and should only be considered when conventional treatment options, including microsurgical clipping, are not feasible. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. A reversible molecular valve

    PubMed Central

    Nguyen, Thoi D.; Tseng, Hsian-Rong; Celestre, Paul C.; Flood, Amar H.; Liu, Yi; Stoddart, J. Fraser; Zink, Jeffrey I.

    2005-01-01

    In everyday life, a macroscopic valve is a device with a movable control element that regulates the flow of gases or liquids by blocking and opening passageways. Construction of such a device on the nanoscale level requires (i) suitably proportioned movable control elements, (ii) a method for operating them on demand, and (iii) appropriately sized passageways. These three conditions can be fulfilled by attaching organic, mechanically interlocked, linear motor molecules that can be operated under chemical, electrical, or optical stimuli to stable inorganic porous frameworks (i.e., by self-assembling organic machinery on top of an inorganic chassis). In this article, we demonstrate a reversibly operating nanovalve that can be turned on and off by redox chemistry. It traps and releases molecules from a maze of nanoscopic passageways in silica by controlling the operation of redox-activated bistable [2]rotaxane molecules tethered to the openings of nanopores leading out of a nanoscale reservoir. PMID:16006520

  4. Reverse photoacoustic standoff spectroscopy

    DOEpatents

    Van Neste, Charles W [Kingston, TN; Senesac, Lawrence R [Knoxville, TN; Thundat, Thomas G [Knoxville, TN

    2011-04-12

    A system and method are disclosed for generating a reversed photoacoustic spectrum at a greater distance. A source may emit a beam to a target and a detector measures signals generated as a result of the beam being emitted on the target. By emitting a chopped/pulsed light beam to the target, it may be possible to determine the target's optical absorbance by monitoring the intensity of light collected at the detector at different wavelengths. As the wavelength of light is changed, the target may absorb or reject each optical frequency. Rejection may increase the intensity at the sensing element and absorption may decrease the intensity. Accordingly, an identifying spectrum of the target may be made with the intensity variation of the detector as a function of illuminating wavelength.

  5. Reverse slapper detonator

    DOEpatents

    Weingart, Richard C.

    1990-01-01

    A reverse slapper detonator (70), and methodology related thereto, are provided. The detonator (70) is adapted to be driven by a pulse of electric power from an external source (80). A conductor (20) is disposed along the top (14), side (18), and bottom (16) surfaces of a sheetlike insulator (12). Part of the conductor (20) comprises a bridge (28), and an aperture (30) is positioned within the conductor (20), with the bridge (28) and the aperture (30) located on opposite sides of the insulator (12). A barrel (40) and related explosive charge (50) are positioned adjacent to and in alignment with the aperture (30), and the bridge (28) is buttressed with a backing layer (60). When the electric power pulse vaporizes the bridge (28), a portion of the insulator (12) is propelled through the aperture (30) and barrel (40), and against the explosive charge (50), thereby detonating it.

  6. Reversible fluctuation rectifier

    NASA Astrophysics Data System (ADS)

    Sokolov, I. M.

    1999-10-01

    The analysis of a Feynman's ratchet system [J. M. R. Parrondo and P. Español, Am. J. Phys. 64, 1125 (1996)] and of its electrical counterpart, a diode engine [I. M. Sokolov, Europhys. Lett. 44, 278 (1998)] has shown that ``fluctuation rectifiers'' consisting of a nonlinear element (ratchet, diode) and a linear element (vane, resistor) kept at different temperatures always show efficiency smaller than the Carnot value, thus indicating the irreversible mode of operation. We show that this irreversibility is not intrinsic for a system in simultaneous contact with two heat baths at different temperatures and that a fluctuation rectifier can work reversibly. This is illustrated by a model with two diodes switched in opposite directions, where the Carnot efficiency is achieved when backward resistivity of the diodes tends to infinity.

  7. Reverse Osmosis Optimization

    SciTech Connect

    2013-08-01

    This technology evaluation was prepared by Pacific Northwest National Laboratory on behalf of the U.S. Department of Energy’s Federal Energy Management Program (FEMP). The technology evaluation assesses techniques for optimizing reverse osmosis (RO) systems to increase RO system performance and water efficiency. This evaluation provides a general description of RO systems, the influence of RO systems on water use, and key areas where RO systems can be optimized to reduce water and energy consumption. The evaluation is intended to help facility managers at Federal sites understand the basic concepts of the RO process and system optimization options, enabling them to make informed decisions during the system design process for either new projects or recommissioning of existing equipment. This evaluation is focused on commercial-sized RO systems generally treating more than 80 gallons per hour.

  8. Reverse Osmosis Optimization

    SciTech Connect

    McMordie Stoughton, Kate; Duan, Xiaoli; Wendel, Emily M.

    2013-08-26

    This technology evaluation was prepared by Pacific Northwest National Laboratory on behalf of the U.S. Department of Energy’s Federal Energy Management Program (FEMP). ¬The technology evaluation assesses techniques for optimizing reverse osmosis (RO) systems to increase RO system performance and water efficiency. This evaluation provides a general description of RO systems, the influence of RO systems on water use, and key areas where RO systems can be optimized to reduce water and energy consumption. The evaluation is intended to help facility managers at Federal sites understand the basic concepts of the RO process and system optimization options, enabling them to make informed decisions during the system design process for either new projects or recommissioning of existing equipment. This evaluation is focused on commercial-sized RO systems generally treating more than 80 gallons per hour.¬

  9. Sex Reversal in Amphibians.

    PubMed

    Flament, Stéphane

    2016-01-01

    Amphibians have been widely used to study developmental biology due to the fact that embryo development takes place independently of the maternal organism and that observations and experimental approaches are easy. Some amphibians like Xenopus became model organisms in this field. In the first part of this article, the differentiation of the gonads in amphibians and the mechanisms governing this process are reviewed. In the second part, the state of the art about sex reversal, which can be induced by steroid hormones in general and by temperature in some species, is presented. Also information about pollutants found in the environment that could interfere with the development of the amphibian reproductive apparatus or with their reproductive physiology is given. Such compounds could play a part in the amphibian decline, since in the wild, many amphibians are endangered species. © 2016 S. Karger AG, Basel.

  10. Reverse shoulder arthroplasty.

    PubMed

    Smithers, Christopher J; Young, Allan A; Walch, Gilles

    2011-12-01

    The reverse shoulder arthroplasty emerged as a potential solution for those patients who could not be managed effectively with a conventional total shoulder arthroplasty. Grammont revolutionized the design by medializing and distalizing the center of rotation and utilizing a large convex glenoid surface and concave humeral component with a neck-shaft angle of 155°. This design has been highly successful in cuff deficient shoulders, and indications continue to broaden. Many mid-term studies have improved upon the early encouraging results. Long-term studies are starting to emerge, demonstrating good survivorship, but progressive functional and radiographic deterioration continue to be concerning. Careful patient selection and attention to appropriate technique are required to reduce the current high rate of complications. New prosthesis designs are continuing to develop to address some of these limitations.

  11. Biochemical Reversal of Aging

    NASA Astrophysics Data System (ADS)

    Ely, John T. A.

    2006-03-01

    We cite our progress on biochemical reversal of aging. However, it may be circa 2 years before we have necessary substances at low cost. Meanwhile, without them, a number of measures can be adopted providing marked improvement for the problems of aging in modern societies. For example, enzymes are needed to excrete toxins that accelerate aging; Hg is the ultimate toxin that disables all enzymes (including those needed to excrete Hg itself). Low Hg level in the urine, due to loss of excretory ability, causes the diagnosis of Hg toxicity to almost always be missed. Hg sources must be removed from the body! Another example is excess sugar; hyperglycemia decreases intracellular ascorbic acid (AA) by competitively inhibiting the insulin- mediated active transport of AA into cells. Thus, immunity is impaired by low leucocyte AA. AA is needed for new proteins in aging tissues. Humans must supplement AA; their need same as in AA-synthesizing mammals.

  12. Reversed-polarity regions

    NASA Technical Reports Server (NTRS)

    Tang, F.

    1982-01-01

    It is found by a statistical study of 58 reversed-polarity regions (RPRs) covering the 11-year period 1969-1979 that RPRs (1) have a lifespan comparable to normal active regions, (2) do not show a tendency to rotate toward a more normal alignment, and (3) have stable configurations that do not suggest stress due to their anomalous magnetic alignment. As in normal regions, RPR magnetic complexity is found to be the primary factor in flare productivity. Weak-field RPRs produce no flares, and regions with complex spots produce more flares than regions with non-complex spots by a factor of five. The main difference between RPRs and normal regions lies in complex spot frequency, with less that 17% of normal active regions having such spots and fewer than 1.8% having long-lived complex ones, while 41% of RPRs have complex spots and 24% have long-lived complex spots.

  13. Reversed-polarity regions

    NASA Technical Reports Server (NTRS)

    Tang, F.

    1982-01-01

    It is found by a statistical study of 58 reversed-polarity regions (RPRs) covering the 11-year period 1969-1979 that RPRs (1) have a lifespan comparable to normal active regions, (2) do not show a tendency to rotate toward a more normal alignment, and (3) have stable configurations that do not suggest stress due to their anomalous magnetic alignment. As in normal regions, RPR magnetic complexity is found to be the primary factor in flare productivity. Weak-field RPRs produce no flares, and regions with complex spots produce more flares than regions with non-complex spots by a factor of five. The main difference between RPRs and normal regions lies in complex spot frequency, with less that 17% of normal active regions having such spots and fewer than 1.8% having long-lived complex ones, while 41% of RPRs have complex spots and 24% have long-lived complex spots.

  14. Multiple stimulus reversible hydrogels

    DOEpatents

    Gutowska, Anna; Krzyminski, Karol J.

    2003-12-09

    A polymeric solution capable of gelling upon exposure to a critical minimum value of a plurality of environmental stimuli is disclosed. The polymeric solution may be an aqueous solution utilized in vivo and capable of having the gelation reversed if at least one of the stimuli fall below, or outside the range of, the critical minimum value. The aqueous polymeric solution can be used either in industrial or pharmaceutical environments. In the medical environment, the aqueous polymeric solution is provided with either a chemical or radioisotopic therapeutic agent for delivery to a specific body part. The primary advantage of the process is that exposure to one environmental stimuli alone will not cause gelation, thereby enabling the therapeutic agent to be conducted through the body for relatively long distances without gelation occurring.

  15. Multiple stimulus reversible hydrogels

    DOEpatents

    Gutowska, Anna; Krzyminski, Karol J.

    2006-04-25

    A polymeric solution capable of gelling upon exposure to a critical minimum value of a plurality of environmental stimuli is disclosed. The polymeric solution may be an aqueous solution utilized in vivo and capable of having the gelation reversed if at least one of the stimuli fall below, or outside the range of, the critical minimum value. The aqueous polymeric solution can be used either in industrial or pharmaceutical environments. In the medical environment, the aqueous polymeric solution is provided with either a chemical or radioisotopic therapeutic agent for delivery to a specific body part. The primary advantage of the process is that exposure to one environmental stimuli alone will not cause gelation, thereby enabling the therapeutic agent to be conducted through the body for relatively long distances without gelation occurring.

  16. Transconjunctival Blepharoptosis Surgery: A Review of Posterior Approach Ptosis Surgery and Posterior Approach White-Line Advancement

    PubMed Central

    Patel, Vikesh; Malhotra, Raman

    2010-01-01

    Posterior approach blepharoptosis surgery, via the transconjunctival route, was probably the first method of surgery employed to shorten the levator palpebrae superioris (LPS) muscle. A review of the literature demonstrates how surgery has evolved since Blaskovics’ first described his technique in 1923. We describe our newer method of posterior approach white-line advancement blepharoptosis repair which is now an option in the majority of aponeurotic ptosis with moderate to good levator function. PMID:21339897

  17. Transconjunctival blepharoptosis surgery: a review of posterior approach ptosis surgery and posterior approach white-line advancement.

    PubMed

    Patel, Vikesh; Malhotra, Raman

    2010-12-14

    Posterior approach blepharoptosis surgery, via the transconjunctival route, was probably the first method of surgery employed to shorten the levator palpebrae superioris (LPS) muscle. A review of the literature demonstrates how surgery has evolved since Blaskovics' first described his technique in 1923. We describe our newer method of posterior approach white-line advancement blepharoptosis repair which is now an option in the majority of aponeurotic ptosis with moderate to good levator function.

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

    ERIC Educational Resources Information Center

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

    2012-01-01

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

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

    ERIC Educational Resources Information Center

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

    2012-01-01

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

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

    PubMed Central

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

    2012-01-01

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