ASSESSMENT OF FINE AND GROSS MOTOR DYSDIA DOCHOKINESIA IN SCHIZOPHRENIC-PATIENTS - DEVELOPMENT OF METHODS AND FIRST RESULTS OF A COMPUTER-BASED MICROANALYSIS

Subtle disturbances of psychomotor coordination known as neurological soft signs have frequently been reported for schizophrenic patients. A n increased interest in neurophysiological correlates of the disease h as recently led to more systematic investigations. Nevertheless, no qu antitative methods for the assessment of neurological soft signs have been developed that could provide a more detailed analyses than the cl inical examination. With reference to concepts and methods used in exp erimental motor research this paper reports on 1) the development of c omputerbased methods for recording simple repetitive movements (diadoc hokinesia) of the fingers and the hand, 2) an empirical investigation of the power of a number of quantitative parameters to discriminate be tween schizophrenics and healthy controls under various instructions, and 3) the possible influence of neuroleptic-induced side effects (rig idity) on these parameters. The results demonstrate an increased motor variability in schizophrenic patients. Relative slowing is found only in fine motor diadochokinesia. A microanalysis of the velocity and ac celeration profiles reveals evidence for subtle disturbances even in t he control of single trajectories in some patients. Correlation with c linically rated extrapyramidal symptoms were due to a small number of patients with marked motor rigidity.