The electroencephalogram in Tourette syndrome.

The electroencephalogram (EEG) was studied in 38 patients with Tourette syndrome. Psychometric tests and neurological evaluation identified patients with signs of additional central nervous system dysfunction. Thirteen patients (34%) had some EEG abnormality. In contrast to findings by other investigators, epileptiform activity was uncommon (only 2 out of 38). Most of the patients with EEG abnormalities either had other objective signs of neurological dysfunction or were taking haloperidol, a drug known to disturb the EEG.