Orthostatic hypotension in patients with dementia

Orthostatic hypotension (OH) is a reduction in systolic and/or diastolic blood pressure that occurs immediately after standing, during the first 3 minutes or after prolonged standing, which is called delayed OH. Its prevalence increases with the age and could be the result of reversible conditions as hypovolemia and chronic-irreversible ones as diabetes mellitus, Parkinson's disease, dementia with Lewy Bodies. OH could be also drug-induced by antidepressants, antipsychotics, levodopa, diuretics, antihypertensive drugs. The relationship between OH, brain hypoperfusion and cognitive impairment has been studied and it is also known a correlation between initial OH and dementia in patients with supine hypertension. Too high or too low blood pressure could alter cerebral blood flow self-regulation, providing hypoperfusion and predisposing to white matter lesions, which are implicated in cognitive impairment. Leukoaraiosis, could therefore be the link between orthostatic hypotension and cognitive decline. Patients with autonomic failure showed a worst cognitive performance. Even if Parkinson's disease and dementia with Lewy Bodies are typically characterized by OH, this latter is also found in patients with Alzheimer's disease. The clinical presentation of OH in patients with dementia is often atypical and less symptomatic. The treatment is based on a careful re-evaluation of drug therapy, behavioral strategies and specific drugs.