Epidemiology of cavernous malformations.

Cavernous malformations, accounting for approximately 5-15% of all vascular abnormalities in the central nervous system, are angiographically occult lesions which most often present with seizures, rather than acute hemorrhage. Widely variable across populations, the incidence of cavernous malformations has been reported to be 0.15-0.56 per 100 000 persons per year, with an annual hemorrhage rate of 0.6-11% per patient-year. Seen in 0.17-0.9% of the population, up to one-half are familial, and at least three gene loci have been associated with a familial form, more common among Hispanic Americans. Most cavernous malformations are supratentorial, with 10-23% in the posterior fossa, and approximately 5% found in the spine.