Intermanual coordination in relation to different clinical subgroups in right-handed patients with schizophrenic and other psychotic disorders.

BACKGROUND: Interhemispheric transfer in psychotic patients is still a controversial issue. Based on the fact that intermanual coordination is associated with interhemispheric transfer, scores in intermanual coordination were investigated in patients with psychotic disorders.
METHOD: Intermanual coordination was assessed by alternating finger-tapping in 73 adult right-handed in-patients with schizophrenic and other psychotic disorders and was compared with that of 75 healthy right-handed controls. Five clinical subgroups of patients whose diagnoses were based on the DSM-IV classification were specified.
RESULTS: Scores in intermanual coordination in the patients as a whole did not differ from those of the controls. When, however, different clinical subgroups and various manifestations of symptoms were taken into consideration, the scores among those subgroups differed significantly. For instance, patients with residual schizophrenia and chronic symptoms showed lower values in intermanual coordination than did patients with schizoaffective disorders and prevailing acute symptoms.
CONCLUSIONS: The assessment of intermanual coordination may provide new insights into the functional coupling of both hemispheres in schizophrenic and other psychotic disorders and may be of a certain prognostic value. Because of its non-invasive, fast and simple application, this approach is thought to be especially suited for investigating acute psychiatric in-patients.