The aim of the study was to analyse EEG investigation to diagnose the tic disorders in children and adolescents.

The analysis was conducted on a group of 76 patients admitted to the Department of Developmental Neurology between 2000-2005 years to diagnose the tic disorders. The average of children's age was 11,4 +/- 3,7 years. In investigated group of patients there were 62 boys (81,6%) and 14 girls (18,4%). The video-EEGs were carried out at 7 patients (22,4%).

There were recorded a single sharp waves in 37 patients (47,4%) and the groups of sharp waves in 21 cases (27,6%). Accordingly there were registered the spike and wave complexes in 7 cases (9,2%) and the sharp and wave complexes in 4 cases (5,3%) in EEG. The generalized paroxysmal activity was recorded in 7 patients (9,1%). The abnormal activity appeared in the temporal part of cerebral hemispheres in 41 children (53,9%). The hiperventilation activated EEG recording of 33 children (43,4%). In 18 cases (23,7%) the abnormal graphoelements didn't appeare in EEG recording. The video recording and the clinical observations during EEG invstigation didn't revealed any coincidence between changes in EEG recording and the involuntary movements presented by patients.

The resting, routine EEG revealed abnormalities in most cases. Therefore video-EEG recording enabled to differentiate tics from epileptic seizure by finding any corelation between the occurrence of involuntary movements and abnormal graphoelements recorded during in EEG investigation.