Natural history of brainstem cavernous malformations

OBJECTIVE: To review the natural history and determine the rates of intra- and extralesional hemorrhaging of brainstem cavernous malformations (cavernomas) monitored by one neuro-ophthalmology service. METHODS: A record review of all patients with brainstem cavernomas who were evaluated by a neuroophthalmology service between 1987 and 1999 was performed. We recorded the clinical symptoms and Rankin disability grade at presentation, during the worst clinical episode, and at the last follow-up examination. Magnetic resonance imaging scans were reviewed for evidence of intralesional hemorrhage (a bleeding episode), edema, or venous anomalies, and the cavernoma size was assessed. RESULTS: Thirty-seven patients (age range, 6-73 yr; mean age at presentation, 37.5 yr) underwent a mean of 4.9 years of follow-up monitoring. At presentation, there were 27 bleeding events and 8 nonhemorrhagic events; 2 patients did not exhibit symptoms. Patients who were at least 35 years of age exhibited a lower risk of bleeding episodes (odds ratio, 0.15; 95% confidence interval, 0.1-0.4). Cavernomas of at least 10 mm were associated with a higher risk of bleeding episodes (odds ratio, 3.48; 95% confidence interval, 1.3-9.4). Thirty-nine bleeding episodes occurred in 31 patients, yielding a bleeding rate of 2.46%/yr. There were eight rebleeding episodes, yielding a rebleeding rate of 5.1%/yr. Three patients experienced extralesional bleeding episodes; all of these patients experienced rebleeding. Of the 39 follow-up magnetic resonance imaging scans, the cavernoma size was unchanged in 66.7%, smaller in 18%, and larger in 15%. At the last follow-up examination, the mean Rankin grade was 1.0 for all patients, 0.6 for the 25 nonsurgically treated patients, and 1.4 for the 12 surgically treated patients. CONCLUSION: Rebleeding is not more common among patients who first present with bleeding, and it often has little effect on the neurological status of patients. Significant morbidity attributable to a brainstem cavernoma occurred in 8% of patients during follow-up monitoring of medium duration.