Neurological soft signs in schizophrenia.

A new scale for neurological soft signs (NSS) was constructed and consists of 17 items compiled from the literature. The scale was found to have a high internal reliability (Cronbach's alpha 0.83) and a high interrater reliability (0.88). According to the results of a factor analysis, NSS are covered by five factors: 'motor coordination', 'integrative functions', 'complex motor tasks', 'righ/left and spatial orientation' and 'hard signs'. Using this scale, the associations of NSS with clinical course and brain alterations were investigated. NSS varied with the clinical course and were significantly correlated with some BPRS subscales, in particular 'thought disorder'. In addition, the 'motor coordination' soft signs were found to correlate with morphological alterations in the basal ganglia.