Parkinson disease and comorbid cerebrovascular disease.

Optimal management of chronic diseases not only requires tackling of the primary disease processes, but also necessitates timely recognition and treatment of comorbid conditions. In this article, we illustrate this two-pronged approach for two common age-related disorders: Parkinson disease (PD) and cerebrovascular disease (CVD). We first discuss the pathophysiological mechanisms that could provide a link between PD and CVD. Patients with PD have a series of risk factors that could promote development of CVD, but also have several protective factors. We then review the available clinical, radiological and neuropathological evidence to support an association between these two conditions. We conclude by discussing the potential implications for clinical practice, highlighting how comorbid CVD could alter the clinical presentation of PD and reviewing the possibilities for prevention and secondary prophylaxis. Additional research will be needed to fully evaluate the prevalence and clinical relevance of comorbid CVD in PD. Pending further evidence, we recommend that cerebral neuroimaging should be considered if patients with initially uncomplicated PD develop-either acutely or chronically-prominent and/or treatment-resistant gait impairment, postural instability, depression, cognitive decline, or urinary incontinence. Finding comorbid CVD in such patients could have prognostic implications, and could necessitate treatment to arrest further progression of CVD.