Cavernous malformations and hemorrhage risk.

Widespread availability of magnetic resonance imaging has helped our understanding of the natural history of cavernous malformations (CMs) of the brain. CMs present with diverse clinical manifestations. Supratentorial CMs are often identified incidentally. The clinical presentation corresponds with lesion location. Symptomatic, hemorrhagic CMs of the brainstem pose a challenging clinical problem as they are often associated with high surgical morbidity. In order to study the natural history of CM, we performed a prospective analysis on a series of patients who were sent to us for management. During the mean prospective follow-up interval of 34 months, 9 hemorrhages occurred. History of prior hemorrhage was the most important risk factor for subsequent hemorrhage. The annual hemorrhage was 0.6% in patients who never had a symptomatic hemorrhage. Patients who had prior hemorrhage have a higher (4.5%) annual hemorrhage rate.