Trial Report Phenylephrine Alters Phase Synchronization between Cerebral Blood Velocity and Blood Pressure in CFS with Orthostatic Intolerance,2024,Medow & Stewart

https://journals.physiology.org/doi/abs/10.1152/ajpregu.00071.2024

NEW & NOTEWORTHY

We evaluated cognitive function before and after CO2, acetazolamide, and phenylephrine, which mitigate orthostatic reductions in cerebral blood velocity. Neither CO2 nor acetazolamide affected N-back testing (% correct answers) during an orthostatic challenge. Only phenylephrine improved upright N-back performance in ME/CFS, as it both blocked hyperventilation and increased CO2 significantly compared with those untreated. And only phenylephrine resulted in improved PSI values in both ME/CFS and control while upright, suggesting improved cerebral autoregulation.