Relation of neurological soft signs to psychiatric symptoms in schizophrenia

INTRODUCTION: Although several studies have identified abnormal rates of neurological soft signs (NSS) as a manifestation of CNS dysfunction in schizophrenia, differences in sample populations have contributed to a discrepancy in empirical findings. Furthermore, little is known about the potential of NSS to predict a clinical response to antipsychotic medications. The present study tests the associations between NSS and schizophrenia symptomatology and examines NSS as a potential marker for predicting treatment response. METHODS: Nineteen unmedicated male schizophrenia patients were treated prospectively with haloperidol for six weeks. The subjects were assessed for pre and post-treatment NSS and schizophrenia symptomatology (Brief Psychiatric Rating Scale, BPRS). RESULTS: NSS at baseline were significantly associated with baseline symptoms on the Positive, Negative, and Psychological Discomfort BPRS subscales. NSS showed a strong trend toward improvement during six weeks of a prospective haloperidol trial. Hierarchical linear regression analyses indicated that more severe baseline NSS predicted poorer response to haloperidol treatment as measured by post-treatment BPRS Total subscale scores. DISCUSSION: NSS at untreated baseline are associated with baseline symptom severity, and elevated NSS are predictive of a smaller degree of improvement in symptoms after antipsychotic treatment. These findings are consistent with the hypothesis that NSS are linked to the neuropathology that underlies schizophrenia symptomatology and course.