The Frequency of Dementia among Patients with Parkinson Disease

Parkinson Disease (PD) is a chronic and progressive disease of the nervous system. Cognitive impairment caused by Parkinson Disease may range from a single isolate symptom to sever dementia. The aim of this study is to estimate the prevalence of dementia in the patients affected by Parkinson Disease. This study is a cross sectional study which was performed on 60 patients suffering from Parkinson Disease who referred to the neurology clinic of Shahrivar 17th Hospital during the years of 2004-2005. After examining and defining the present signs and symptoms, all the patients were classified into four grades, according to Unified PD Rating Scale (UPDRS). Then, the presence of dementia was investigated based on the criteria as presented in “Diagnostic and Statistical Manual of Mental Disorders”, the revised fourth edition (DSMIV). Also, we evaluated the risk factors such as hypertension, hyperlipedemia, smoking, and diabetes mellitus in the cases of study. 60 patients with peak incidence were included in the study. The patients aged at a range of 55-65years old. The male patients in the study outnumbered the females, with a ratio of 3/1. Dementia was found to be present in 42% of the patients. Out of 20 patients who were diagnosed with abnormal CT results, 80% (16 patients) had dementia while the other 20 % (4 patients) did not. As the findings of the study indicate, Grade 3 of PD was the most frequent type among the patients with dementia while Grade 2 of PD was the most prevalent in the patients without it. In terms of the risk factor of smoking, it was found to be frequent in 28% of the patients with dementia, but in only 3% of the patients without dementia. The frequency of hypertension was measured as16% among the patients with dementia and 14% among the patients who did not have dementia. 36% of the patients with dementia were involved in at least one of the risk factors whereas that was the case with 25% of the patients who did not have dementia. From the findings of the study, it can be concluded that the frequency of dementia may increase by ascending the severity of Parkinson Disease. Dementia in these patients was not found to have any statistical relationship with the risk factors such as smoking, hypertension and diabetes. However, there is a need to investigate the problem in a larger population to be able to generalize the results of this study.