Cortical evoked potentials in Gilles de la Tourette's syndrome--a single case study

Average cortical evoked potentials (AEPs) to auditory stimulation and AEP recovery functions were investigated in a 13-year-old boy suffering from Gilles de la Tourette's syndrome. Data obtained from the patient while on and off haloperidol were compared with data from a group of normal control subjects matched for age and sex. Latencies of the P2 and N2 components of the AEP were noticeably shorter in the Tourette's syndrome patient than in the control group. Recovery from stimulation, as estimated by the cortical evoked potential to the second of two closely spaced stimuli, was faster in the patient than the controls. After the patient's treatment with haloperidol, the latencies of the P2 and N2 components of the AEP and the speed of recovery from stimulation appeared to be no different in the patient than in the control subjects. Findings suggested that cortical excitability is higher in the Tourette's syndrome patient, whose AEPs also showed evidence of a maturational advance over the normal subjects.