Prophylaxis with diphenylhydantoin and phenobarbital and alumina-gel monkey model. I. Twelve months of treatment: seizure, EEG, blood, and behavioral data.

Utilizing an alumina-gel epileptic monkey model, with instrumentation for continuous monitoring of all overt, spontaneous motor seizures, the efficacy of pharmacologic prophylactic treatment of posttraumatic epilepsy was explored. The alumina-gel model provides a relatively standardized brain trauma from monkey to monkey, resulting in virtually complete assurance that all animals will manifest, in time, electrical and clinical seizures if not treated. Thirteen rhesus monkeys were divided into two groups of 8 drug-treated and 5 placebo animals, respectively. Administration of diphenylhydantoin and phenobarbital in a combined regimen commenced within 48 hr of the alumina-gel injections. After 1 year the monkeys were withdrawn from either their drugs or placebo and followed for a subsequent 4 month period. The data for the first 12-month period indicate that anticonvulsant treatment of potentially epileptic monkeys decreased both the frequency and severity of seizures they would have had without treatment. All animals manifested an electrical focus and overt seizures, but the drug monkeys had only partial seizures whereas the placebo monkeys exhibited secondarily generalized tonic-clonic seizures. The follow-up, no-treatment data of 4 months are reported in the following paper.