A woman who couldn't speak: report of methotrexate neurotoxicity.

The association between methotrexate therapy and idiosyncratic neurological complications is well recognised in children. This case illustrates the importance of considering the diagnosis of methotrexate toxicity in an adult patient with behavioural and speech disturbances, who received it by intrathecal route only and in whom the only indicator was an abnormal electroencephalographic study.