SCHIZOPHRENIA AND THE LIMBIC SYSTEM

Abstract

There is accumulating evidence that Summary the brain's limbic system is pathologically involved in at least some cases of schizophrenia. The evidence comes from schizophrenia-like symptoms observed in cases of known limbic-system neuropathology, and from signs of limbic-system dysfunction in some patients diagnosed with schizophrenia. Prominent in the first group are cases of temporallobe epilepsy, encephalitis, and brain tumours. Suggestions of limbic-system dysfunction are found in studies of the earliest changes observed by schizophrenic patients themselves, studies of the site of action of psychedelic drugs, and studies of electro-encephalographic abnormalities in schizophrenics. Whereas the results of scalp-electrode studies of schizophrenics remain equivocal, at least four separate studies using implanted electrodes have recorded electrical abnormalities specifically from limbic-system structures. Recent findings of " soft " neurological signs in schizophrenic patients, including autonomic dysfunction, proprioception, vestibular dysfunction, and eye-tracking, also point towards disturbances in the subcortical area of the brain which includes the limbic system. Although pathological changes in the limbic system have been described in some patients with schizophrenia, failure to follow up and/or replicate such findings leaves these studies in doubt. The evidence linking the limbic system to schizophrenia, although admittedly circumstantial, is sufficient to warrant a serious look for further clues. The limbic system appears to be the part of the brain of first choice for elucidating the biology and pathomorphology of this disease.