Event-related brain potentials show changed attentional mechanisms in Gilles de la Tourette Syndrome.

In many patients the Gilles de la Tourette Syndrome (TS) is associated with the childhood Attention Deficit Hyperactivity Disorder. To gain a general view of attentional processes in TS we recorded event-related brain potentials (ERPs) in 12 TS patients and in a matched control group. Four visual attention experiments with different levels of complexity were done (oddball task, pop-out experiment, figure extraction and figure conjunction task). The reaction times did not differ significantly between groups. The Tourette patients' event-related brain potentials showed an increased amplitude of the N2 component to targets in the simple oddball and pop-out experiments. While both groups had similar P3b latencies to targets in the figure extraction experiment, Tourette patients responded less accurately in the most complex figure conjunction task and had increased P3b latencies. This is interpreted as evidence for a stronger attentional effort of the Tourette patients to obtain behavioural results similar to control subjects in easy attentional tasks. Consequently, Tourette patients show a reduced performance in complex attentional tasks.