January 13, 2015

Cognitive changes in ‘standing’ syndrome

Patients with orthostatic intolerance – problems when standing – have cognitive changes, even when seated, compared to healthy individuals.

by Daren Diiorio


Postural tachycardia syndrome (POTS) is a common cause of chronic orthostatic intolerance – problems when standing – in premenopausal females. The disease is characterized by a sustained exaggerated heart rate increase upon standing, without a drop in blood pressure (orthostatic hypotension). Patients additionally report mental clouding, though this phenomenon is poorly understood.

Amy Arnold, Ph.D., MSCI, Satish Raj, M.D., MSCI, and colleagues in the Vanderbilt Autonomic Dysfunction Center tested the hypothesis that POTS patients exhibit deficits in cognitive function during standardized neuropsychological testing when compared to healthy individuals. Under controlled conditions, the researchers discovered that seated POTS patients exhibited impaired selective attention, cognitive processing speeds and executive function. No differences were observed in measures of sustained attention, psychomotor speed, memory function or verbal fluency.

In the January issue of Clinical Science, the team reports that the selectivity of cognitive dysfunction observed may provide new insight into the pathophysiological mechanisms behind this disease. Further studies will probe mechanisms and potential clinical strategies to better manage associated cognitive dysfunction.

This research was supported by grants from the National Institutes of Health (HL102387, NS065736, HL056693, TR000445, MH094535, MH088329) and the American Heart Association.

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