Significance and meaning of neurological signs in schizophrenia.

The authors review studies of abnormal signs on clinical neurological examination of schizophrenic patients. In spite of a number of methodologic limitations, the cumulative evidence strongly argues that there are more neurological signs in schizophrenic patients than in nonpsychiatric control subjects. Although less consistent, there is considerable evidence of more neurological signs in schizophrenic patients than in patients with affective disorders or with mixed, nonpsychotic disorders. The existing literature suggests several preliminary hypotheses with respect to neuroanatomical localization of neurological signs, subtyping of schizophrenia, and utility of studies of relatives at high risk and family history studies. Directions for future research in these areas are described.