[The incidence of postoperative epilepsy and prophylactic anticonvulsants in patients with intracranial aneurysm]

The occurrence of epileptic seizures is not rare after craniotomy. The authors examined the incidence of postoperative epilepsy in 150 patients of intracranial aneurysm. Anticonvulsants were given to all patients after operation, but in 12 cases anticonvulsants were discontinued because of liver dysfunction. One hundred and eight out of 138 cases (78%) were prescribed polypharmaceutically, and 30 of 138 cases (22%) were monopharmaceutically. The daily dose of anticonvulsants was as follows; diphenylhydantoin (DPH) was 150-300 mg, phenobarbital (PB) was 50-100 mg, valproic acid (VPA) was 600-1200 mg, and carbamazepin (CBZ) was 200-600 mg. Postoperative epilepsy occurred in 14 of 150 cases (9.3%); 13 cases with anticonvulsants, and 1 case without anticonvulsants. The site of aneurysm was as follows; 6 cases (10.3%) of AC aneurysm, 3 cases (9.7%) of MC aneurysm, 1 case (2.4%) of IC aneurysm, and 4 cases (21.1%) of multiple aneurysm. The interval between operation and epileptic seizure was ranged 2 to 57 months (mean 19.8 months); in 7 cases (50%) within 1 year, and in 13 cases (93%) within 3 years. The authors emphasize that prophylactic use of anticonvulsants is effective to control subclinical epileptic seizures, prescribing anticonvulsants to all patients after craniotomy in general. The medication of anticonvulsants for 3 years would be necessary for avoiding postoperative epileptic seizure.