Neurologic Comorbidities in Schizophrenia

Brain abnormalities have long been assumed to be involved in the pathophysiology of schizophrenia.Magnetic resonance imaging studies have identified numerous structural and functional imagingabnormalities, such as reduced brain volume, frontal lobe volume, and hippocampal volume, in patientswith schizophrenia. Neurologic disorders, such as movement disorders, neurologic abnormalities,and cognitive deficits, are often seen years before the onset of schizophrenia. Many of these abnormalitiesmay be predictive of the development of schizophrenia, but unfortunately, they are usuallyoverlooked. In addition, treatment with antipsychotics may affect brain structure, further complicatingthe ability to detect changes due to the neuropathology of psychosis. This article reviews the structuraland functional imaging abnormalities found in patients with schizophrenia and the neurologicdisorders that commonly coexist with the disorder. The role that treatment with atypical antipsychoticsmay or may not have in contributing to neurologic abnormalities is also discussed. Throughincreased awareness of these abnormalities, the importance of obtaining a complete neurologic historyand examination of patients with schizophrenia at the onset of their illness and before initiatingpharmacotherapy will become evident. Such recognition may permit earlier identification and treatmentof schizophrenia, thus potentially improving long-term outcome.