Reversible Cerebral Vasoconstriction Syndrome: A Comprehensive Systematic Review

OBJECTIVE: We aimed to analyze clinical characteristics, treatment patterns, and prognosis of patients with reversible cerebral vasoconstriction syndrome (RCVS). MATERIALS AND METHODS: Two investigators independently searched PubMed and EMBASE, and 191 cases were included in this study. Information regarding demographics, triggering factors, brain imaging findings, treatment modalities, recurrence, and clinical outcome was collected. RESULTS: The mean age of the patients was 39.9 years, and 155 (81.2%) were female. The most common triggering factor for RCVS was an exposure to vasoactive substances (41.4%), followed by pregnancy/postpartum (20.9%), and sexual intercourse (10.5%). Multifocal stenosis (84.0%) and beading shape (82.4%) were the leading abnormal findings on angiography, while cerebral ischemic lesions (47.6%) and cerebral hemorrhage (mainly subarachnoid hemorrhage) (35.1%) were the main findings on brain computed tomography (CT)/magnetic resonance imaging (MRI). Calcium channel blockers (nimodipine/verapamil) were the most commonly used medications (44.5%) in the treatment of RCVS. Multivariate analysis identified that RCVS was precipitated by trauma/surgery/procedure (hazard ratio (HR): 3.29, 95% confidence interval (CI) (1.21-8.88), p=0.019), and presence of aphasia/neglect/apraxia during the acute phase of the disease (HR: 3.83, 95% CI (1.33-11.05), p=0.013) were found to be the two independent risk factors for residual neurological deficit after RCVS. CONCLUSIONS: In our systematic review, vasoactive substances were the most frequent triggers for RCVS, which was most commonly accompanied by angiographic findings of multifocal stenotic lesions. Patients with RCVS precipitated by trauma or surgical procedures and those with focal cortical deficits had a higher risk of residual neurological deficits, and these patients should closely be monitored

Empirical assessment of biases in cerebrospinal fluid biomarkers of Alzheimer's disease: an umbrella review and re-analysis of data from meta-analyses

OBJECTIVE: Alzheimer’s disease (AD) is a leading cause of years lived with disability in older age, and several cerebrospinal fluid (CSF) markers have been proposed in individual meta-analyses to be associated with AD but field-wide evaluation and scrutiny of the literature is not available. MATERIALS AND METHODS: We performed an umbrella review for the reported associations between CSF biomarkers and AD. Data from available meta-analyses were reanalyzed using both random and fixed effects models. We also estimated between-study heterogeneity, small-study effects, excess significance, and prediction interval. RESULTS: A total of 38 meta-analyses on CSF markers from 11 eligible articles were identified and reanalyzed. In 14 (36%) of the meta-analyses, the summary estimate and the results of the largest study showed non-concordant results in terms of statistical significance. Large heterogeneity (I2≥75%) was observed in 73% and small-study effects under Egger’s test were shown in 28% of CSF biomarkers. CONCLUSIONS: Our results suggest that there is an excess of statistically significant results and significant biases in the literature of CSF biomarkers for AD. Therefore, the results of CSF biomarkers should be interpreted with caution