Stroke and idiopathic Parkinson's disease: does a shortage of dopamine offer protection against stroke?

Data on the relationship between idiopathic Parkinson's disease (IPD) and stroke are conflicting. In this study, we examined the frequency of IPD in stroke patients registered in the Maastricht Stroke Registry. With the use of three different search strategies, we found eight individuals with IPD amongst a total of 1,516 stroke patients. We had expected to find approximately 30 IPD patients (relative risk 0.27; 95% confidence interval 0.11-0.53), based on IPD prevalence figures from a Dutch population-based study. We speculate that dopamine deficiency may protect against ischaemic brain damage, perhaps by reducing the effects of excitotoxicity.