Increasing orthostatic stress impairs neurocognitive functioning in CFS

[Guest guest]

Summary and practical significance

The present study is the first to show that increasing

orthostatic stress impairs cognitive performance in

CFS/POTS subjects. The present study may have a

strong practical application to those with CFS/POTS.

Our results show that CFS/POTS subjects do not have

differences in intelligence, but rather experience cognitive

impairment mainly due to the effect of orthostatic stress,

especially during difficult tasks.

In addition, we show that the information processing

speed of CFS/POTS subjectsmay be affected by standing,

especially during difficult tasks. In school, CFS/POTS

subjects may require more time during testing, and

tasks to be done while standing will be more difficult.

During testing, an increased allotment of time may be

beneficial to the performance of CFS/POTS subjects.

Workplace arrangements that limit standing may improve

performance for individuals with CFS/POTS.

Additional work is necessary to determine whether

orthostatic stress and/or cognitive challenges have

detrimental effects in CFS subjects without POTS or

in POTS subjects without CFS. Although we would

speculate that, in CFS subjects without POTS, cognitive

challenges would correlate with decreased accuracy and

RT, we are unsure about the effect of orthostatic stress

on neurocognitive function in CFS subjects who are

orthostatically tolerant. We would also assume that, in

POTS subjects without CFS, increasing orthostatic stress

would result in decreased accuracy and RT.

Overall, orthostatic stress impaired the cognitive

abilities of CFS/POTS subjects compared with control

subjects who were not affected.Changes in cerebral blood

flow were not related to neurocognitive impairment.

Future work is necessary to link physiological changes

observed in CFS/POTS subjects with their cognitive

deficits.

FUNDING

This work was supported by the National Heart, Lung,

and Blood Institute [grant numbers 1-F30-HL-097380

(to A.J.O.), 1-RO1-HL-074873 (to J.M.S.), 1-RO1-HL-

087803 (to J.M.S.)], and the Chronic Fatigue and Immune

Deficiency Syndrome Association of America (grant to

M.S.M.).