Phenylephrine Alters Phase Synchronization between Cerebral Blood Velocity and Blood Pressure in Chronic Fatigue Syndrome with Orthostatic Intolerance

[pattismith]

Phenylephrine Alters Phase Synchronization between Cerebral Blood Velocity and Blood Pressure in Chronic Fatigue Syndrome with Orthostatic Intolerance​

2024

Abstract​

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) with orthostatic intolerance (OI) is characterized by neuro-cognitive deficits perhaps related to upright hypocapnia and loss of cerebral autoregulation (CA).

We performed N-back neurocognition testing and calculated the phase synchronization index (PhSI) between Arterial Pressure (AP) and cerebral blood velocity (CBV) as a time-dependent measurement of cerebral autoregulation in 11 control (mean age=24.1 years) and 15 ME/CFS patients (mean age=21.8 years).

All ME/CFS patients had postural tachycardia syndrome (POTS). A 10-minute 60⁰ head-up tilt (HUT) significantly increased heart rate (109.4 ± 3.9 vs. 77.2 ± 1.6 beats/min, P <0.05) and respiratory rate (20.9 ± 1.7 vs. 14.2 ± 1.2 breaths/min, P < 0.05) and decreased end-tidal CO2 (ETCO2; 33.9 ± 1.1 vs. 42.8 ± 1.2 Torr, P < 0.05) in ME/CFS vs. control

In ME/CFS, HUT significantly decreased CBV compared to control (-22.5% vs -8.7%, p<0.005).

To mitigate the orthostatic CBV reduction, we administered supplemental CO2, phenylephrine and acetazolamide and performed N-back testing supine and during HUT.

Only phenylephrine corrected the orthostatic decrease in neurocognition by reverting % correct n=4 N-back during HUT in ME/CFS similar to control (ME/CFS=38.5±5.5 vs. ME/CFS+PE= 65.6±5.7 vs. Control 56.9±7.5).

HUT in ME/CFS resulted in increased PhSI values indicating decreased CA. While CO2 and Acetazolamide had no effect on PhSI in ME/CFS, PE caused a significant reduction in PhSI (ME/CFS=0.80±0.03 vs ME/CFS+PE= 0.69±0.04, p< 0.05) and improved cerebral autoregulation.

Thus, PE improved neurocognitive function in ME/CFS patients, perhaps related to improved neurovascular coupling, cerebral autoregulation and maintenance of CBV.


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

 

[andyguitar]

Thus, PE improved neurocognitive function in ME/CFS patients, perhaps related to improved neurovascular coupling, cerebral autoregulation and maintenance of CBV.

Good find @pattismith Some unpleasant side effects with this drug but interesting to see the theraputic possibilities of it.

 

[pattismith]

Good find @pattismith Some unpleasant side effects with this drug but interesting to see the theraputic possibilities of it.

I remember a time in my life when I used PE to help me coming out of bed.

The side effect after some months was shaking hands, so I had to stop it.

What I find interesting is that it becomes more and more obvious that brain fog is related to bad cerebral vascular autoregulation. (with or without POTS)

I feel we also have altered cerebral fluid regulation as a secondary effect.