Factors associated with cognitive impairment in patients with Parkinson disease: an urban study

BACKGROUND AND AIMS: Parkinson disease (PD) is the second most prevalent neurodegenerative disorder after Alzheimer disease. Besides motor presentations, cognitive impairment is among the other likely complications as the illness progresses. This study aimed to determine the prevalence of cognitive impairment in PD and the factors associated with the cognitive impairment.
MATERIALS AND METHODS: A cross-sectional, descriptive study was conducted on all PD patients at different stages of their illness, in two major tertiary hospitals in Malaysia with their caregivers, over a three month period in 2002. Patients' cognitive functions were tested using the Mini Mental State Examination (MMSE). Important sociodemographic data and relevant clinical information of the patients as well as caregivers' information on income, duration of care-giving, relationship with the patient, and other relevant variables were gathered. Patients' level of functioning was assessed using the Activities of Daily Living (ADL) index. Staging of illness was done based on the Hoehn and Yahr Scale.
RESULTS: Out of 115 eligible patients, 35% were in the 60-69 age group with 57% in stage 2 of illness, A total of 29% of patients experienced various degrees of cognitive impairment , with almost half (47%) in the stage 3 and 4 exhibiting MMSE scores <24. Factors which were significantly associated with impaired cognitions were race, educational level and stage of illness.
CONCLUSION: Cognitive impairment was fairly common in PD and the severity of impairment in cognition and physical functioning increased with the advancement of the illness.