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. Hierarchal 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. (C) 2007 Elsevier B.V. All rights reserved.