Recurrent exophytic meningioma in pregnancy.

BACKGROUND: Meningiomas are slow-growing tumors that may present in pregnancy because of accelerated growth. We present the case of a recurrent meningioma in two separate pregnancies in the same woman. CASE: A 35-year-old woman presented at 30 weeks of gestation with limb weakness, vomiting, and a progressive decreased level of consciousness with an enlarging forehead mass. Imaging revealed a massive extra-axial exophytic tumor. An emergency craniotomy was performed, complicated by massive blood loss. Final pathology showed a grade I meningioma positive for progesterone receptors. Maternal-fetal outcome was good, with return of normal neurologic status and elective delivery at 38 weeks of gestation. CONCLUSION: Pregnancy is associated with accelerated meningioma growth and recurrence. Treatment during pregnancy is possible and requires a multidisciplinary approach.

Augmentation of chemotherapy-triggered glioma cell apoptosis by blockade of arachidonic acid metabolism--the potential role of ceramide accumulation.

There has been recent interest in using cyclooxygenase-2 inhibitors in an effort to increase the efficacy of chemotherapy and/or radiation for treatment of malignant brain tumors. Although the mechanism is unclear, one result may be the accumulation of arachidonic acid (AA). AA is the key substrate for several biochemical pathways involved in the inflammatory cascade, including the cyclooxygenase (COX) enzymes. Cyclooxygenase-1 and cyclooxygenase-2 metabolize AA to produce prostaglandins and thromboxanes. Levels of these enzymes and their products are upregulated in gliomas, especially in malignant tumors. Likewise, the enzyme 5-lipoxygenase, also elevated in malignant gliomas, metabolizes AA to produce leukotrienes. Alternatively, enzymes of the cytochrome p450 family can metabolize AA to various products, some of which may aid glioma growth and angiogenesis. Unmetabolized AA activates the enzyme neutral sphingomyelinase, which produces ceramide, a second messenger and potent activator of apoptosis. It is hypothesized that simultaneous blockade of the COX, lipoxygenase, and/or cytochrome p450-mediated pathways would lead to greater accumulation of intracellular AA, resulting in elevated ceramide levels, thereby priming glioma cells for treatment-induced apoptotic cell death. Manipulation of AA/bioactive lipid metabolism, using readily available, well-tolerated medications may have the potential to increase the efficacy of currently used glioma treatments.

Ventricular catheter exchange using a peel-away outer catheter.

Ventricular catheter replacement can be challenging, especially in patients with small ventricles. Shunt malfunction due to ventricular catheter obstruction can occur without ventricular enlargement, such as in the setting of slit-ventricle syndrome or benign intracranial hypertension. The authors describe a simple technique for ventricular catheter exchange using a peel-away catheter. In the limited initial experience of the senior author (G.S.C.), this technique appears to be safe and effective. To the authors' knowledge, this method has not been described in the neurosurgical literature before.

MicroRNA and diseases of the nervous system.

The recent discovery of microRNAs (miRNAs) has caused the traditional central dogma of molecular biology to be rewritten. miRNAs are small, noncoding pieces of ribonucleic acid that exert control over gene expression at the posttranscriptional level. They appear to play important roles in the normal development and functioning of the nervous system and in disease states. To understand future diagnostic and therapeutic advances arising from the study of miRNAs, it is crucial that neurosurgeons understand what miRNAs are, how they function, and the role they play in diseases of the nervous system. This article serves as a basic introduction to miRNAs and their ever-expanding role in the neurological sciences.

A giant fusiform basilar aneurysm treated by bilateral vertebral artery occlusion.

OBJECTIVE AND IMPORTANCE: Fusiform aneurysms of the vertebrobasilar arteries that progressively enlarge causing symptomatic brainstem compression are dangerous and their treatment is difficult. A patient with such an aneurysm treated successfully with staged, microsurgical occlusions of the proximal vertebral arteries is described, and the literature pertaining to this rare condition is briefly reviewed. CLINICAL PRESENTATION: A 48-year-old man with a fusiform basilar trunk aneurysm of uncertain etiology presented initially with transient ischemic attacks (TIAs) of the posterior circulation that ceased with anticoagulation. Four years later he presented again with progressive ataxia, dysphagia and dysphonia due to considerable enlargement of the aneurysm causing brainstem compression. INTERVENTION: Staged microsurgical vertebral artery occlusions proximal to the aneurysm were performed. The second (left) vertebral artery was clipped only after the patient passed its temporary occlusion with an endovascular test balloon. The aneurysm subsequently thrombosed, the distal basilar artery kept patent by a single (left) posterior communicating artery. The patient's clinical condition improved markedly over a number of months as the aneurysm mass atrophied. CONCLUSION: Giant vertebrobasilar aneurysms are rare but treacherous lesions, sometimes justifying aggressive management. Carefully selected patients with progressive and severe symptoms due to brainstem compression may tolerate proximal vertebral artery occlusions, provided there is adequate collateral flow to the basilar termination and all of its perforating branches.