SOFT SIGNS AND NEUROPSYCHOLOGICAL PERFORMANCE IN SCHIZOPHRENIA

Objective: Both neuropsychological impairment and neurological soft si gns have been documented in at least a subset of patients with schizop hrenia. The purpose of the present study was to examine the relationsh ip between soft signs and neuropsychological performance in patients w ith schizophrenia in order to address the Issue of whether soft signs are related to global or more selective cognitive impairment. Method: Patients with a DSM-III-R diagnosis of schizophrenia (N=176) were give n a standardized neuropsychological battery and underwent a neurologic al examination. The study group was dichotomized on the basis of prese nce or absence of neurological soft signs. Results: Patients with neur ological soft signs (N=68) demonstrated significantly poorer performan ce on neuropsychological tasks that assessed timed motor speed and mot or coordination (e.g., finger tapping the Purdue Pegboard task, and pa rt B of the Trail Making Test). These findings continued to be signifi cant even after lifetime medication exposure, extrapyramidal symptoms, and abnormal involuntary movements were used as covariates. Conclusio ns: These findings support the notion that soft signs ale a manifestat ion of a localizable behavioral deficit of the systems that are involv ed In motor speed, coordination, and sequencing and are not indicative of global cognitive impairment. The specific deficit in motor abiliti es is consistent with the types of neurological soft signs that are mo st frequently reported and suggests involvement of frontal/subcortical circuitry in schizophrenia.