UNTERSUCHUNG DER FEIN- UND GROBMOTORISCHEN DYSDIADOCHOKINESE SCHIZOPHRENER PATIENTEN: METHODENENTWICKLUNG UND ERSTE ERGEBNISSE EINER COMPUTERGESTUTZTEN MIKROANALYSE

Subtle disturbances of psychomotor coordination known as neurological soft signs have frequently been reported for schizophrenic patients. An increased interest in neurophysiological correlates of the disease has recently led to more systematic investigations. Nevertheless, no quantitative methods for the assessment of neurological soft signs have been developed that could provide a more detailed analyses than the clinical examination. With reference to concepts and methods used in experimental motor research this paper reports on 1) the development of computer-based methods for recording simple repetitive movements (diadochokinesia) of the fingers and the hand, 2) an empirical investigation of the power of a number of quantitative parameters to discriminate between schizophrenics and healthy controls under various instructions, and 3) the possible influence of neuroleptic-induced side effects (rigidity) 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 acceleration profiles reveals evidence for subtle disturbances even in the control of single trajectories in some patients. Correlation with clinically rated extrapyramidal symptoms were due to a small number of patients with marked motor rigidity.