Cardiovascular dysautonomia and cognition in Parkinson's Disease - a possible relationship.

Dementia in advanced Parkinson's Disease (PD) is a fatal milestone resulting in reduced life expectancy and nursing home placement. Cognitive impairment and cardiovascular dysautonomia are common and debilitating non-motor symptoms that frequently coexist in PD since the early stages and progress in subsequent years. In particular, blood pressure (BP) abnormalities, including orthostatic hypotension (OH), supine hypertension (SH) and the loss of nocturnal BP fall (non-dipping) in PD have been associated with cognitive deterioration. They usually have multifactorial aetiology, including neuronal (central and peripheral) mechanisms and concomitant intake of medications. BP abnormalities can influence cognition in many ways, including repeated cerebral hypoperfusion leading to cerebral ischaemic lesions, higher burden of white matter hyperintensities, and possible impact on neurodegenerative process in PD. They are often asymptomatic and remain unrecognised, hence 24-hour ambulatory BP monitoring is recommended in patients with clinical symptoms of dysautonomia. Management is challenging and should address the multifactorial nature of BP disturbances. The aim of this review was to present the state of current knowledge regarding the possible relationship between cardiovascular dysautonomia and cognition in PD, its diagnosis and treatment.