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 imaging abnormalities, such as reduced brain volume, frontal lobe volume, and hippocampal volume, in patients with schizophrenia. Neurologic disorders, such as movement disorders, neurologic abnormalities, and cognitive deficits, are often seen years before the onset of schizophrenia. Many of these abnormalities may be predictive of the development of schizophrenia, but unfortunately, they are usually overlooked. In addition, treatment with antipsychotics may affect brain structure, further complicating the ability to detect changes due to the neuropathology of psychosis. This article reviews the structural and functional imaging abnormalities found in patients with schizophrenia and the neurologic disorders that commonly coexist with the disorder. The role that treatment with atypical antipsychotics may or may not have in contributing to neurologic abnormalities is also discussed. Through increased awareness of these abnormalities, the importance of obtaining a complete neurologic history and examination of patients with schizophrenia at the onset of their illness and before initiating pharmacotherapy will become evident. Such recognition may permit earlier identification and treatment of schizophrenia, thus potentially improving long-term outcome.