Cerebrospinal fluid and blood thiamine concentrations in phenytoin-treated epileptics

Thiamine and folate levels in blood and cerebrospinal fluid (CSF) were determined by microbiological assays in 23 control subjects and 11 phenytoin-treated epileptics. There was no significant difference between the two groups for serum and CSF folate levels. There was, however, a statistically significant difference between the groups for both whole blood thiamine and CSF thiamine levels. Epileptic patients being treated with phenytoin had lower values than control subjects.