Motor neurological soft signs are strongly correlated with verbal fluency among patients with schizophrenia attending UKMMC psychiatric clinic

Abstract

Introduction

Neurological soft signs (NSS) are subtle indicator of brain dysfunction, which are present in excess among patients with schizophrenia. Its clinical significance remains unclear despite extensive researches.

Objective

To determine the proportion of schizophrenia patients who have motor NSS and then to compare the performance in verbal fluency between these two groups; with and without motor NSS.

Method

This cross-sectional study utilized the Brief Motor Scale (BMS) to investigate the presence of motor NSS in 80 schizophrenia patients attended Universiti Kebangsaan Malaysia Medical Centre (UKMMC) psychiatric clinic. The diagnosis was confirmed by Mini International Neuropsychiatic Interview (MINI). Symptomatology and abnormal motor movement were assessed using the Brief Psychiatric Rating Scale (BPRS) and Abnormal Involuntary Movement Scale (AIMS) respectively. A brief battery of cognitive tests covering aspects of attention, working memory and executive function was administered. Bivariate and multivariate analyses were applied to look for any relationship between study factors.

Results

Majority of schizophrenia patients (68.8%) in this study have motor NSS. The motor NSS were correlated with verbal fluency, digit span forward, digit span backward, and trail making B but not with trail making A (p < 0.05). However, verbal fluency was the only factor that remained significantly correlated with motor NSS after multivariate analysis.

Conclusions

The assessment of motor NSS represents a brief, inexpensive and meaningful tool in psychiatry. Together with verbal fluency, it has the potential as an illness marker and a link between neurobiological research and clinical practice.