The Brief Motor Scale (BMS) for the assessment of motor soft signs in schizophrenic psychoses and other psychiatric disorders

Subtle motor impairment is an important aspect of neurological soft signs (NSS) which are frequently found in psychiatric patients-particularly schizophrenic patients. On the basis of data collected in previous studies using two different NSS scales, the most reliable and discriminative signs of motor impairment were identified to construct a brief 10-item rating scale. Subsequently, the new scale was applied to a sample of subacute patients with schizophrenic psychoses (N = 82) and healthy controls (N = 33). Factor analysis identified two factors which were labeled "motor coordination" and "motor sequencing". Both the total score and the subscores showed high internal consistency and test-retest reliability. There were highly significant group differences on the total score and the subscores as well as on each individual task. The scale has high sensitivity (84.1%) and specificity (87.9%) indicating that it may provide an effective instrument for the screening of subjects with neurodysfunction as well as for monitoring motor dysfunction in the clinical course of psychiatric disorders.