Relationships among impairment, disability, handicap, burden of care, economic expenses, event-related potentials and regional cerebral blood flow in Parkinson's disease

Background:  Relationships between impairment, disability and handicap in neurological diseases such as stroke and spinal cord injury have been studied using the framework of the international classification of impairment, disability and handicap, defined by World Health Organization. Those relationships in Parkinson's disease have rarely been studied on a statistical basis. Methods:  In order to identify relationships between impairment, disability, handicap, burden of care, economic expenses and neurophysiological dysfunction in patients with Parkinson's disease, we made quantitative evaluations of these parameters in 24 patients and 14 care-givers. Impairment was measured by symptomatic assessment for motor and autonomic impairments and neuropsychological assessment using the revised version of Hasegawa's dementia scale, the mini-mental state examination, and the self-rating depression scale. Disability was measured by Hoehn and Yahr scale, Barthel index, and the comprehensive activities of daily living index for the elderly. Handicap was measured by the Craig handicap assessment and reporting technique. Scores for burdens of care on principal care-givers had physical and psychosocial aspects. Neurophysiological dysfunction was studied by measuring visual event-related potentials and regional cerebral blood flow. Results:  Motor and cognitive impairments, disability and handicap significantly correlated to each other. In particular, disability and handicap were strongly correlated. The burden of care on care-givers, economic expenses, visual event-related potentials and regional cerebral blood flow were significantly correlated with impairment, disability and handicap. Conclusion:  Further investigations are anticipated to confirm practical values of symptomatic, neuropsychological, electrophysiological and neuroimaging evaluations to predict burden of care on families and economic expenses for patients with Parkinson's disease.