Cerebral cavernous malformations: natural history and clinical management.

Cavernous malformations (CMs) are angiographically-occult clusters of dilated sinusoidal channels that may present clinically with seizures, focal neurological deficits and/or hemorrhage. Across natural history studies, the annual hemorrhage rate ranged from 1.6-3.1% per patient-year, decreasing to 0.08-0.2% per patient-year for incidental CMs and to 0.3-0.6% for the collective group of unruptured CMs. Prior hemorrhage is a significant risk factor for subsequent CM hemorrhage. Hemorrhage clustering, particularly within the first 2 years, is an established phenomenon that may confound results of natural history studies evaluating the rate of rehemorrhage. Indeed, rehemorrhage rates for hemorrhagic CMs range from 4.5-22.9% in the literature. Surgical resection is the gold standard treatment for surgically-accessible, symptomatic CMs. Incidental CMs or minimally symptomatic, surgically inaccessible eloquent lesions may be considered for observation. Stereotactic radiosurgery is a controversial treatment approach of consideration only for cases of highly aggressive, surgically inaccessible CMs.