Cognitive Dysfunctions and Soft Neurological Signs in Schizophrenic Patients

Kim, Jae Gyeong; Lee, Sang Ick; Hong, Kyung Sue; Ahn, Soh Yeon; Kim, Ji Hae; Kim, Eyong

Abstract

OBJECTIVES
Clinical studies have shown cognitive dysfunctions and soft neurological signs in schizophrenic patients and these findings have been suggested as evidence of organic bases in the pathophysiology of schizophrenia. This study was intended to investigate the characteristics of cognitive deficits and soft neurological signs in schizophrenia and, to determine whether any abnormality in these functions can be regarded as a trait marker of the illness which is independent of antipsychotic treatment and clinical improvement. We also investigated the correlation between cognitive deficits and soft neurological signs reflecting cognitive dysmetria, respectively.
METHODS
Twenty schizophrenic patients were assessed for the soft neurological signs and cognitive functions before and after neuroleptic treatment. The patients had been medicated for at least 3 weeks with one of the atypical neuroleptics. Cognitive functions were evaluated by Trail making A, B, Stroop test and Word fluency test. Soft neurological signs were assessed by Cambridge Neurological Inventory(Part 2). Positive and Negative Syndrome Scale(PANSS) and Clinical Global Impression(CGI) were used to assess the clinical severity and Extrapyramidal Symtoms Rating Scale was used to estimate the extrapyramidal symptoms. Cognitive functions and soft neurological signs of twenty normal controls were assessed with the same scale.
RESULTS
Before treatment, schizophrenic patients showed significant impairments on cognitive function tests(Trail Making A, B, Stroop Test) and soft neurological sign tests(8 items:Grasp reflex, Go/no-go, Finger thumb opposition, Rhythm tapping, Finger agnosia, Fist-edge-palm, Left-right orientation, Extinction). Although significant clinical improvements were observed after the treatment, there were no significant changes in cognitive functions and soft neurological signs(except for Go/no-go test and Finger agnosia). Among the soft neurological signs of the patients, abnormality in Rhythm tapping was significantly correlated with cognitive deficits.
CONCLUSION
Schizophrenic patients showed characteristic cognitive deficits and soft neurological signs which were independent of medication and clinical symptoms. And these two characteristics were partly correlated with each other.