Cognitive profile in early stage Parkinson disease

Abstract

Purpose: Parkinson’s disease (PD) is a neurodegenerative disorder characterized by both motor and nonmotor symptoms mainly due to striatal dopamine deficiency. Cognitive dysfunction is one of nonmotor symptoms. The purpose of this study is to determine the cognitive dysfunction with practical screening tests and to investigate relationship between cognitive dysfunction and clinical severity in early stage of PD (EPD) Materials and Methods: EPD patients and healthy control group were included into the study. Mini mental state examination (MMSE), digit span (DS), clock drawing (CD), verbal and visual memory tests were applied to all cases. Unified Parkinson’s Disease Rating Scale (UPDRS) and Hoehn & Yahr Staging (H&Y) tests were performed to EPD patients. Correlation of neurocognitive tests with UPDRS and H&Y scores were examined in EPD patients. Results: There were 30 EPD patients (11 female/19 male) and 20 healthy controls (10 female/10 male). There was a significant difference only in CD test between EPD and healthy controls. EPD with H&Y stage 1. group had higher score on backward DS, CD, and visual memory tests than EPD with H&Y stage 2. Verbal memory test scores had negatively correlated with UPDRS scores. Conclusion: The first impaired test was CD in EPD compared to control group. Other cognitive tests (backward DS, verbal and visual memory tests) were also impaired with increasing severity of disease. MMSE was not different from the control group and did not change with increasing severity of disease. MMSE alone is not enough for evaluating of EPD, other cognitive tests have to be used.