Neurocognitive Functioning in Treatment:resistant Schizophrenics

Lee, Kang Joon; Kwak, Dong Il

Abstract

Neurocognitive research focusing on cognitive deficits in schizophrenia resulted in several important yet potentially contradictory findings. Studies have shown that chronic patients have a diffuse pattern of cognitive impairment which is frequently indistinguishable from that of focal brain-damaged patients. Some reports have suggested that there is a focal pattern of deficit, such as left hemisphere dysfunction, frontal lobe impairment, or the dysfunction of the temporal-limbic cortex. The aim of this study is to evaluate neurocognitive functions in treatment-resistant schizophrenic patients. The subjects are 33 treatment-resistant schizophrenics. And their neurocognitive functions are compared with those of 37 treatment-reactive schizophrenic patients and 35 normal control subjects. Patients with a history of neurological disease, alcohol dependence, substance abuse and mental retardation are excluded. The diagnosis of specific subtypes are made after a review of all available information including medical records, historical data from informants, and by the confirmation of 2 board-certified psychiatrists. To control potential neurocognitive effects of medications, all patients had drug-free period of 1 week. The following tests are administered to each subjects; Mini Mental State Examination-Korean(MMSE- K), Brief Psychiatric Rating Scale(BPRS), Clinical Global Impression(CGI), Positive and Negative Syndrome Scale(PANSS), and Neurological Rating Scale for Extrapyramidal Symptoms(EPS scale). And they are assessed with a part of Vienna Test System which is computerized neurocognitive function tests which evaluate attention, eductive ability, reproductive ability, visuoperceptual analysis, vigilance, visual immediate memory, the speed of information-processing, judgement, and fine motor coordinations. The results indicated that treatment-resistant schizophrenic patients have deficits in eductive ability, visuoperceptual analysis, sustained attention, information-processing, reaction time and motor coordination. The study provides useful information about neurocognitive functions of carefully diagnosed subgroups of chronic schizophrenic pateints, especially treatment-resistant patients.