Factor structure of neurologic examination abnormalities in unmedicated schizophrenia

The heterogeneity and uncertain significance of neurologic exam abnormaliti es in schizophrenia prompted us to evaluate their factor structure. We admi nistered a modified version of the Neurological Evaluation Scale (NES) to 1 03 unmedicated patients with schizophrenia. Data were distilled by combinin g right- and left-side scores, and by eliminating superfluous, rarely abnor mal and unreliable items from the analysis. Exploratory principal component s analysis yielded four factors: repetitive motor tasks (fist-ring, fist-ed ge-palm, alternating fist-palm, dysdiadochokinesis); cognitive-perceptual t asks (memory, audiovisual integration, right-left orientation, face-hand te st, rhythm tapping reproduction); balancing tasks (Romberg, tandem gait); a nd the palmomental reflex. Evaluation of the relationship between these fac tors and clinical and demographic variables revealed a robust correlation b etween the cognitive-perceptual factor and full-scale IQ score. This analys is is a step toward developing empirical subscales of a modified NES, which may provide insights into the nature of neurologic impairment in schizophr enia and may prove clinically useful. (C) 2000 Published by Elsevier Scienc e Ireland Ltd.