Giant cell polymyositis associated with myasthenia gravis and thymoma

We report a case of a 40-year-old woman who developed generalized muscle weakness over a period of 2 months. Physical examination revealed palpable masses in her arms and hands. Serum creatine kinase levels were elevated. Electromyography showed myopathic changes and 3 Hz repetitive nerve stimulation revealed a decremental pattern on repetitive nerve stimulation. Muscle MRI demonstrated increased signal intensity in the biceps brachii on T1-weighted images. Chest CT scan showed a mediastinal mass suggestive of thymoma. Muscle biopsy revealed giant cell polymyositis. The patient was treated with cholinesterase inhibitors and corticosteroids with improvement of strength, and subsequently underwent thymectomy followed by radiotherapy.     

神经肽Y对海马神经元“癫痫样”动作电位的影响

目的探讨神经肽Y(neuropeptide Y,NPY)对海马神经元"癫痫样"动作电位的影响。方法用无镁细胞外液处理原代培养12 d的海马神经元3 h,诱导海马神经元癫痫样放电,建立海马神经元癫痫样放电模型;用全细胞膜片钳电流钳模式检测神经元动作电位,分别给予0.1μmol/L和1μmol/L NPY各1μL,给药时间10 s,观察其对神经元动作电位频率及波幅的影响。结果无镁细胞外液处理神经元3 h,可以形成稳定的海马神经元癫痫样放电模型,频率16～23 Hz,波幅75～96 mV。模型组神经元动作电位频率为(18.00±2.32)Hz,而0.1μmol/L和1μmol/L NPY组分别为(4.75±1.04)Hz和(1.50±0.75)Hz。与模型组相比较,两种浓度NPY组均降低了动作电位发放的频率(P<0.05)。模型组神经元动作电位波幅为(82.25±5.17)mV,而0.1μmol/L和1μmol/L NPY组分别为(49.75±2.49)mV和(40.00±2.20)mV。与模型组相比较,两种浓度NPY组均降低了动作电位发放的波幅(P<0.05)。两种浓度NPY之间相比较,也有统计学差异(P<0.05)。1μmol/LNPY明显抑制了动作电位发放的频率和波幅。结论 NPY能够抑制无镁细胞外液诱发的神经元癫痫样电活动,为应用NPY抑制癫痫发作提供了细胞电生理学证据。     

Clinical features and risk factors of Raynaud’s phenomenon in primary Sjögren’s syndrome

Clinical Rheumatology - The aim at the current study was to investigate the clinical characteristics and risk factors of Raynaud’s phenomenon (RP) in patients with primary...     

Over-shunting associated myelopathy

Intracranial hypotension typically presents following cerebrospinal fluid (CSF) leak, but can be induced by CSF diversion. Classically, patients present with positional headache, but less common symptoms include neck pain and cranial nerve palsies. To our knowledge, the neurosurgical literature contains six reports of patients with symptomatic cervical, epidural venous plexus engorgement as the result of CSF shunting. The patient presented herein is a 26-year-old woman with shunt-dependent, congenital hydrocephalus. She presented with rapidly progressive cervical myelopathy following ventriculoperitoneal shunt revision. Imaging revealed engorgement of the cervical epidural venous plexus and mass effect on the cervical spinal cord. “Over-shunting associated myelopathy” is a rare complication of CSF diversion that should be familiar to physicians who routinely evaluate patients with intracranial shunts.     

Biomechanics of thoracolumbar burst fractures: Methods of induction and treatments

Much controversy exists regarding the mechanism of burst fracture (BF) induction and the proper techniques to treat such fractures. As such, there is a great need for validated preclinical models in which to study these injuries. In this study, an electronic search of the PubMed database (MEDLINE) was performed and the results were filtered to obtain only studies with a biomechanical focus. Forty five biomechanical studies were obtained, from which four distinct methods of injury induction were identified. Twenty one (46.7%) involved clinically relevant techniques for treating BF, involving anterior, posterior, circumferential, or a combination of approaches. Fifteen (71.4%) of the treatment studies used unstable spine specimens that do not fit the classical characteristics of BF. Given the consistent use of BF models that do not adhere to classical definitions, the clinical value of ex vivo induction is uncertain.     

CIP2A and PP2A in human leptomeninges,arachnoid granulations and meningiomas

Previously we have found that mitogens stimulate proliferation of meningioma cells of all grades, in part, by activation of the PI3K-PKB/Akt-PRAS40-mTOR pathway regulated to some degree by the tumor suppressor phosphatase PP2A. PP2A activity is inhibited by the oncoprotein cancerous inhibitor of PP2A (CIP2A), which has not been studied in meningiomas to our knowledge. Six fetal and one adult human leptomeningeal samples and 38 meningiomas were evaluated by western blot. Fifteen adult arachnoid granulations and 58 formalin-fixed meningiomas (36 World Health Organization grade I, 15 grade II and seven grade III) were evaluated by immunohistochemistry. The effects of the mitogens platelet derived growth factor-BB (PDGF-BB) and cerebrospinal fluid on CIP2A were also studied. By western blot, CIP2A and PP2A were found in the five fetal and one adult leptomeninges and all meningiomas. By immunohistochemistry, CIP2A was detected in the arachnoid granulations and all meningiomas. CIP2A tended to be higher in grade III tumors. Three fetal leptomeningeal (two grade I and one grade II) and meningioma cells treated with PDGF-BB and/or human cerebrospinal fluid resulted in a slight increase in CIP2A in the leptomeningeal cells but not meningioma cells. Considered the mechanism of action and seen in other neoplasms, these findings raise the possibility that CIP2A may participate in the biology of meningiomas.     

A 10 year retrospective study of surgical outcomes of adult intracranial pilocytic astrocytoma

Pilocytic astrocytomas (PA) are benign neoplasms commonly located in the cerebellum with a peak incidence in the first two decades of life. PA occurrence in adults is rare and very little information is available in the literature about tumour characteristics in this population. This study retrospectively identified 20 adults with PA. The characteristics of the tumour, treatment modalities and patient outcomes are discussed, as well as identifying factors that may be associated with worse prognosis. The mean age at diagnosis was 27 years. The majority of PA were located in the posterior fossa. Other tumour locations included the cerebral hemispheres, brainstem, tectal plate and optochiasmatic region (optic chiasm, hypothalamus and third ventricle). All patients in this study underwent surgery, two received adjuvant chemotherapy and one received adjuvant radiotherapy. Tumour recurrence occurred in six patients and two eventually died from the disease. When achieved, complete tumour resection was found to be curative. Tumour location affects extent of surgical resection; tumours in inaccessible locations were associated with higher rates of recurrence. Overall survival and progression free survival rates were 87% and 60% respectively. The degree of surgical resection and tumour location were found to affect prognosis. Unfavourable outcomes were observed in these adults with PA compared to those expected for a younger population, suggesting a possible association between age and outcome.     

Time interval to surgery and outcomes following the surgical treatment of acute traumatic subdural hematoma

Although the pre-surgical management of patients with acute traumatic subdural hematoma prioritizes rapid transport to the operating room, there is conflicting evidence regarding the importance of time interval from injury to surgery with regards to outcomes. We sought to determine the association of surgical timing with outcomes for subdural hematoma. A retrospective review was performed of 522 consecutive patients admitted to a single center from 2006–2012 who underwent emergent craniectomy for acute subdural hematoma. After excluding patients with unknown time of injury, penetrating trauma, concurrent cerebrovascular injury, epidural hematoma, or intraparenchymal hemorrhage greater than 30 mL, there remained 45 patients identified for analysis. Using a multiple regression model, we examined the effect of surgical timing, in addition to other variables on in-hospital mortality (primary outcome), as well as the need for tracheostomy or gastrostomy (secondary outcome). We found that increasing injury severity score (odds ratio [OR] 1.146; 95% confidence interval [CI] 1.035–1.270; p = 0.009) and age (OR1.066; 95%CI 1.006–1.129; p = 0.031) were associated with in-hospital mortality in multivariate analysis. In this model, increasing time to surgery was not associated with mortality, and in fact had a significant effect in decreasing mortality (OR 0.984; 95%CI 0.971–0.997; p = 0.018). Premorbid aspirin use was associated with a paradoxical decrease in mortality (OR 0.019; 95%CI 0.001–0.392; p = 0.010). In this patient sample, shorter time interval from injury to surgery was not associated with better outcomes. While there are potential confounding factors, these findings support the evaluation of rigorous preoperative resuscitation as a priority in future study.     

Arterial fenestrations and their association with cerebral aneurysms

Fenestrations of intracranial arteries and associated aneurysms are rare. The significance of these fenestrations in relation to aneurysms remains unclear. We present four patients with fenestration-associated aneurysms and a comprehensive review of associations with aneurysms and other vascular lesions. A PubMed search of the literature was conducted from 1970–2012 reporting cases of intracranial aneurysms associated with arterial fenestration or duplications. Data were collected on patient presentation, sex, age, aneurysm and fenestration location, aneurysm treatment, and presence of other vascular lesions. We performed a retrospective review of four patients with intracranial fenestrations associated with aneurysms at our institution from 2012–2013. There were 59 cases of fenestrations and associated aneurysms in the literature. Aneurysms were reported as either arising from (n = 50) or adjacent to but distinct from (n = 13) fenestrations. The most common single fenestration location was at the basilar artery (n = 23, 36.5%); however the majority of fenestrations were in the carotid circulation (n = 34, 54.0%). The majority of patients with aneurysms and fenestrations at all locations except those at the anterior communicating artery (70.5%) presented with subarachnoid hemorrhage. Patients with aneurysms arising from a fenestration or adjacent to a fenestration presented with an additional intracranial vascular lesion in 38% and 31% of cases, respectively. The majority of all aneurysms were treated with microsurgical clipping. Aneurysms associated with cerebral arterial fenestrations are most commonly discovered after subarachnoid hemorrhage and are most often located in the carotid circulation. A high index of suspicion must be maintained for an associated vascular lesion if an intracranial fenestration is discovered.