Frequency of Cognitive Impairment in Patients with Parkinson's Disease

Introduction More than its motor symptoms, cognitive impairment is being increasingly identified as a cause of worse functional outcome, morbidity and mortality, and caregiver dependence in Parkinson's disease (PD). The aim of this study was to identify the frequency of cognitive decline and evaluate the factors associated with it. Methods In this cross-sectional study, 124 PD patients fulfilling the United Kingdom Parkinson's Disease Society Brain Bank Clinical Diagnostic Criteria were included. Motor and non-motor symptoms were recorded. Disease duration, age at the time of onset, and severity of disease on Hoehn and Yahr Scale (HY scale) were recorded. Data was entered and analyzed using SPSSs v. 22.0. Results The ratio of men to women was 7.2:1. The mean age of the participants was 64 ± 10 years (range: 38-82 years). Rigidity (n = 121; 97.5%), bradykinesia (n = 119; 95.9%), and tremor (n = 11; 90.3%) were the three most common symptoms. Cognitive impairment was present in 45 (36.3%) patients. Cognitive decline was more frequent in patients of age less than 50 years at the time of disease onset (p < 0.00001) and in those with disease duration more than 10 years (p = 0.00001). Patients with longer disease duration had more severe disease (stage III or above on HY scale; p = 0.008). Conclusion Motor symptoms such as rigidity, bradykinesia, and tremor remain the most frequent clinical presentation among Pakistani Parkinson's patients. One-third of these patients have cognitive dysfunction. Early age at the time of disease onset and longer duration of disease were associated with cognitive impairment.