Declining mortality in cerebral venous thrombosis: a systematic review.

BACKGROUND AND PURPOSE Cerebral venous thrombosis (CVT) is nowadays considered a disease with a good outcome in most cases, but in the past, these patients were thought to have a grave prognosis. We systematically studied the apparent decline in mortality of patients with CVT over time. METHODS A systematic review of the literature (MEDLINE and EMBASE) was performed. Studies with ≥40 patients with CVT that reported mortality at discharge or follow-up were eligible. Duplicate publications based on the same patient cohort were excluded. Studies were ranked according to the year halfway the period of patient inclusion. Two of the authors independently screened all eligible studies. RESULTS We screened 4585 potentially eligible studies, of which 74 fulfilled the selection criteria. The number of patients per study varied from 40 to 706 (median, 76). Data from 8829 patients with CVT, included from 1942 to 2012, were analyzed. The average age was 32.9 years, and 64.7% were women. There was a significant inverse correlation between mortality and year of patient recruitment (Pearson correlation coefficient, -0.72; P<0.001). In a sensitivity analysis, the correlation remained significant after exclusion of studies published before 1990, retrospective studies, or single-center studies. Both the frequency of focal neurological deficits and coma also decreased significantly over time (correlation coefficient, -0.50 and -0.52). CONCLUSIONS There is a clear trend in declining mortality among patients with CVT over time. Possible explanations are improvements in treatment, a shift in risk factors, and, most importantly, the identification of less severe cases by improved diagnostic methods.