Remote cerebellar hemorrhage after supratentorial procedures (part 1): a systematic review.

A remote cerebellar hemorrhage (RCH) is a spontaneous bleeding in the posterior fossa, which may rarely occurs as a complication of supratentorial procedures, and it shows a typical bleeding pattern defined "the zebra sign." However, its pathophysiology still remains unknown. We performed a comprehensive review collecting all cases of RCH after supratentorial craniotomies reported in literature in order to identify the most frequently associated procedures and the possible risk factors. We assessed percentages of incidence and 95 % confidence intervals of all demographic, neuroradiological, and clinical features of the patients. Univariate and multivariate analyses were used to evaluate their association with outcome. We included 49 articles reporting 209 patients with a mean age of 49.09 ± 17.07 years and a male/female ratio 130/77. A RCH was more frequently reported as a complication of supratentorial craniotomies for intracranial aneurysms, tumors debulking, and lobectomies. In the majority of cases, RCH occurrence was associated with impairment of consciousness, although some patients remained asymptomatic or showed only slight cerebellar signs. Coagulation disorders, perioperative cerebrospinal fluid drainage, hypertension, and seizures were the most frequently reported risk factors. Zebra sign was the most common bleeding pattern, being observed in about 65 % out of the cases, followed by parenchymal hematoma and mixed hemorrhage in similar percentages. A multivariate analysis showed that symptomatic onset and intake of antiplatelets/anticoagulants within a week from surgery were independent predictors of poor outcome. However, about 75 % out of patients showed a good outcome and a RCH often appeared as a benign and self-limiting condition, which usually did not require surgical treatment, but only prolonged clinical surveillance, unless in the event of the occurrence of complications.