Patent foramen ovale and neurosurgery in sitting position: a systematic review.

We have conducted a systematic review of air embolism complications of neurosurgery in the sitting position and patent foramen ovale (PFO) closure. It assesses the risk and benefit of PFO closure before neurosurgery in the sitting position. The databases Medline, Embase, and Cochrane Controlled Trial Register were systematically searched from inception to November 2007 for keywords in both topics separately. In total, 4806 patients were considered for neurosurgery in sitting position and 5416 patients underwent percutaneous PFO closure. The overall rate of venous air embolism during neurosurgery in sitting position was 39% for posterior fossa surgery and 12% for cervical surgery. The rate of clinical and transoesophageal echocardiography detected paradoxical air embolism was reported between 0% and 14%. The overall success rate for PFO closure using new and the most common closure devices was reported 99%, whereas the average risk of major complications is <1%. On the basis of our systematic review, we recommend screening for PFO and considering closure in cases in which the sitting position is the preferred neurosurgical approach. Our proposed management including the time of PFO closure according to available data is presented. However, the conclusions from our systematic review may be limited due to the lack of level A evidence and from using data from observational cohort studies. Thus, definite evidence-based recommendations require prospective evaluation of the issue in well-designed studies.

[Perspectives in the treatment of subarachnoid-hemorrhage-induced cerebral vasospasm]. / Perspectivas en el tratamiento del vasospasmo cerebral inducido por hemorragiasubaracnoidea.

Cerebral vasospasm is still the most important cause of death and disability after rupture of intracranial aneurysms. The therapeutic strategies in the treatment of subarachnoid hemorrhage induced vasospasm vasospasm include four groups: 1) prevention of vasospasm; 2) reversion of vasospasm; 3) improvement of cerebral perfusion; and 4) neuroprotection and rescue therapies. Recent experimental studies allowed the design of phase II clinical studies which demonstrated positive results with medications and compounds such as statins (simvastatin and pravastatin) and endothelin-1 receptor antagonists (clasozentan). Moreover, experimental and clinical evidences showed the advantages of early cerebrospinal fluid drainage, intrathecal administration of NO-donors, effects of Ca2+ protein kinase inhibitor (Fasudil) and catecholamines on the cerebral vessels. This review article summarizes the stage of investigation of these medications and therapeutic strategies which will be relevant in the treatment of cerebral vasospasm.

Perspectivas en el tratamiento del vasospasmo cerebral inducido por hemorragia subaracnoidea / Perspectives in the treatment of subarachnoid-hemorrhage-induced cerebral vasospasm

El vasospasmo cerebral sigue siendo la causa más importante de invalidez y muerte posterior a la ruptura de aneurismas saculares intracerebrales. Las estrategias terapéuticas en el vasospasmo inducido por l a hemorragia subaracnoidea pueden ser agrupadas en cuatro categorías a saber: 1) terapias de prevención; 2)terapias de reversión; 3) terapias para el aumento dela perfusión cerebral; y 4) terapias de neuroprotección y rescate. Estudios experimentales recientes han permitido la realización de estudios clínicos fase II que sugieren resultados positivos con medicamentos que incluyen estatinas (simvastatina y pravastatina) y antagonistas de receptores tipo A de la endotelina-1(clasozentan). De igual manera, evidencias experimentales y clínicas han mostrado las ventajas del drenaje de líquido cefalorraquídeo, administración intratecal de donadores de óxido nítrico, y los efectos desinhibidores de la Ca2+ Protein Kinasa C (Fasudil) y catecolaminas sobre la vascularización cerebral. Este artículo resume el estado de investigación actual de posibles agentes y estrategias terapéuticas relevantes en el tratamiento del vasospasmo cerebral

Cerebral vasospasm is still the most important cause of death and disability after rupture of intracraniala neurysms. The therapeutic strategies in the treatment of subarachnoid hemorrhage induced vasospasm include four groups: 1) prevention of vasospasm;2) reversion of vasospasm; 3) improvement of cerebral perfusion; and 4) neuroprotection and rescue therapies. Recent experimental studies allowed the design of phase II clinical studies which demonstrated positive eresults with medications and compounds such asstatins (simvastatin and pravastatin) and endothelin-1receptor antagonists (clasozentan). Moreover, experimental and clinical evidences showed the advantages of early cerebrospinal fluid drainage, intrathecal administration of NO-donors, effects of Ca2+ protein kinase inhibitor (Fasudil) and catecholamines on the cerebral vessels. This review article summarizes the stage of investigation of these medications and therapeutic strategies which will be relevant in the treatment of cerebral vasospasm

The impact of tumour volume and surgery on the outcome of adults with supratentorial WHO grade II astrocytomas and oligoastrocytomas.

BACKGROUND: The study was performed to elucidate the impact of tumour volume and surgical resection on the long-term outcome of patients with supratentorial, diffuse, World Health Organization (WHO) grade II astrocytomas and oligo-astrocytomas. METHOD: After analysing 79 adult patients consecutively diagnosed between 1991 and 2000, we selected a group of 42 patients treated by surgery without adjuvant therapy. The tumour volume was defined as the whole region of T2-hyperintensity and measured interactively on pre- and postoperative and follow-up Magnetic Resonance Imaging (MRI) using a dedicated imaging software. Volumetric, clinical, and histological data were analysed for correlation with tumour progression (TP), malignant transformation (MT), drop in functional status (DKPS) and overall survival (OS). FINDINGS: Pre- and postoperative tumour volumes, and the involvement of more than one lobe were strongly associated with worse outcome. Preoperative tumour volume was the strongest predictor of OS (p<0.01) and the only predictor of MT (p<0.05). The absolute and relative volumes of tumour removed by surgery were not significantly associated with outcome. CONCLUSIONS. Initial tumour volume, measured as the volume of T2-hyperintensity on MRI, and tumour extension are the strongest predictors of outcome in patients with supratentorial diffuse astrocytic WHO Grade II tumours. The potential benefit of aggressive tumour resection needs to be investigated in a prospective controlled trial.

Michael adducts of ascorbic acid as inhibitors of protein phosphatase 2A and inducers of apoptosis.

Michael adducts of ascorbic acid with alpha,beta-unsaturated carbonyl compounds have been shown to be potent inhibitors of protein phosphatase 1 (PP1) without affecting cell viability at the respective concentrations. Here we were able to show that higher concentrations can partially inhibit PP2A activity and concomitantly induce apoptotic cell death. A nitrostyrene adduct of ascorbic acid proved to be a more potent and effective inhibitor of PP2A as well as a stronger inducer of apoptosis. These adducts only slightly lost their cytotoxic potential in multidrug resistant cells that were 10-fold less sensitive to apoptosis induction by okadaic acid and vinblastine.