Quantitative analysis of motor disturbances in schizophrenic patients

The presence of neurological signs and disturbed psychomotor performance have been consistently confirmed by clinical studies in schizophrenic patients. These parameters are mainly assessed by using clinical rating scales. In recent years, new approaches such as ultrasonic movement analysis systems have been introduced in order to objectively evaluate motor disturbances in schizophrenic patients. Ultrasonic movement analysis systems calculate the three-dimensional positions of tiny markers, which are attached to moving body parts, with high spatial and temporal resolution. Thus, key parameters of gait and hand movements can be determined precisely. This article summarizes and discusses several studies using these new methods. Results indicate that schizophrenia causes a specific motor deficit pattern, with a predominant disturbance of spatial parameters. Conventional antipsychotic treatment usually worsens these deficits, whereas the effects of atypical antipsychotic treatments are less pronounced. Disturbed motor performance can be normalized by external sensory stimuli, but only when no major attentional processes are required, and it can be enhanced by an attentional strategy, but not to the extent that motor parameters are normalized.