Kinematical analysis of motor function in schizophrenic patients: a possibility to separate negative symptoms from extrapyramidal dysfunction induced by neuroleptics?

BACKGROUND: In this prospective matched case-control study, hand movement analysis was conducted using a digitizing tablet (kinematical analysis).

METHODS: The study examined the association of different computer-assessed hand movement variables with clinical pathology (negative symptoms and extrapyramidal motor dysfunction). A sample of 16 schizophrenic patients and 16 healthy controls participated in the study.

RESULTS: At baseline, kinematical analysis indicated a significant higher prevalence of subtle hand motor dysfunction in unmedicated schizophrenic patients (who all exhibited clinically no extrapyramidal dysfunction) in comparison to healthy controls. No association between the observed motor signs and pre-enrollment total long-term butyrophenones exposure has been detected. After 14 days treatment with haloperidol, the hand movement variables, which correlated significantly with clinical rating scores reflecting drug-induced extrapyramidal dysfunction could definitely be separated from the hand movement variables with a close association to clinical rating measuring negative symptoms.

CONCLUSIONS: Results of the comparative analysis at baseline confirm previous findings concerning presence of neurological soft signs in unmedicated schizophrenic patients. Furthermore, results of this pilot study suggest that kinematical analysis by means of a digitizing tablet could be a useful approach towards a differentiation between drug-induced akinetic symptoms and disease-induced negative symptoms.