Study Examines Orthostatic Hypotension, Association With Dementia in Parkinson Disease

A recent study investigating orthostatic hypotension (OH)—a common condition among patients with Parkinson disease—found that the causality between OH and dementia may be bidirectional and early diagnosis is important to improve long-term prognosis.

The study, published by Neuropsychiatric Disease and Treatment, reviewed evidence that OH increased the odds of incident mild cognitive impairment and dementia. The researchers used the MEDLINE database for original research articles published after October 2008 in order to conduct their analysis.

“Orthostatic hypotension (OH) is a disorder in which a sustained drop in blood pressure (BP) is observed in upright posture compared to supine. This is a common disorder in older adults with a prevalence ranging from between 6% and 30% in community-living individuals to over 50% in those living in geriatric institutions,” noted the authors.

The review revealed that in large population-based cohorts OH increased the risk of dementia by up to 50% in the general population. In smaller cohorts, in patients with Parkinson without dementia, the risk of dementia increased between 3- and 7-fold.

Additionally, the researchers found that in patients with α-synucleinopathies there was an increased risk with binary classification of OH and beat-by-beat measures of blood pressure.

“While some discrepancy between studies has been observed, this may be partially due to the method of assessment for OH and the ability to detect temporal variants of OH. The role of OH in the development and progression of cognitive impairment has distinct implications to quality of life,” concluded the authors. “Ultimately, causality between OH and dementia may turn out to be bidirectional, especially in α-synucleinopathies. Early diagnosis and treatment of OH, however, may improve long-term prognosis.”

The researchers suggested that longitudinal, multimodal imaging studies be conducted in order to investigate the pathophysiological underpinnings of the association between dementia and OH.

Reference

Roberson A, Udow S, Espay A, et al. Orthostatic hypotension and dementia incidence: links and implications [published online: August 2, 2019]. Neuropsychiatric Disease and Treatment. doi: 10.2147/NDT.S182123.