THE NATURAL-HISTORY OF CEREBRAL CAVERNOUS MALFORMATIONS

To determine the natural history of brain cavernous malformations, the authors entered patients referred to their center into a prospective registry between 1987 and 1993. All patients underwent magnetic resona nce imaging, which showed the typical appearance of this lesion, and c onservative management was recommended in all. Patients or their refer ring physicians were contacted for follow-up data. The purpose of the study was to define the rate of symptomatic hemorrhage and to determin e the outcome in those patients who had suffered seizures. Follow-up d ata were available for 122 patients with a mean age at entry of 37 yea rs (range 4-82 years). The malformation was located in the brainstem i n 43 cases (35%), the basal ganglia/thalamus in 20 (17%), and a hemisp heric area in 59 (48%). Fifty percent of patients had never had a symp tomatic hemorrhage, 41% had one bleed, 7% had two, and 2% had three. S eizures were reported in 23% of patients and headaches in 15%. Lesions were solitary in 80% of patients and multiple in 20%. The retrospecti ve annual hemorrhage rate (61 bleeds/4550.6 patient-years of life) was 1.3%. The mean prospective follow-up period was 34 months. There were nine bleeds during this time, six with new neurological deficits. in patients without a prior bleed, the prospective annual rate of hemorrh age was 0.6%. In contrast, patients with prior hemorrhage had an annua l bleed rate of 4.5% (p = 0.028). Patient sex (p = 0.97) or the presen ce of seizures (p = 0.11), headaches (p = 0.06), or solitary versus mu ltiple lesions (p = 0.15) were not significant predictors of later hem orrhage. There was no difference in the rate of bleeds between brain l ocations. Four patients with seizures became seizure free and four pat ients without seizures later developed seizures; only one patient deve loped intractable seizures. Fourteen patients (11%) underwent surgery (two after hemorrhage, five with seizures, and seven with progressive deficits), and five had radiosurgery. No patient died in the follow-up period. This study indicates that conservative versus operative manag ement strategies may need to be redefined, especially in patients who present with hemorrhage and who appear to have a significantly increas ed risk of subsequent rehemorrhage.