Orthostatic challenge, cerebral blood flow and neurocognition in CFS

[Marco]

Abstract of a small study that proposes beneficial effects of phenylephrine (alpha adrenergic receptor agonist used for hypotension) on orthostatic challenge induced reduced cerebral blood flow and impaired cognition :

Phenylephrine Alteration of Cerebral Blood Flow During Orthostasis; Effect on N-Back Performance in Chronic Fatigue Syndrome

CONCLUSIONS:

Compared to control, CFS subjects are both more sensitive to orthostatic challenge and to baroreflex/chemoreflex-mediated interventions. Increasing BP with phenylephrine can alter CBFv. In CFS subjects, mitigation of the HUT-induced CBFv decrease with phenylephrine has a beneficial effect on N-Back outcome.

http://jap.physiology.org/content/early/2014/09/30/japplphysiol.00527.2014

 

[Dolphin]

This figure shows evidence that the thinking of people with ME/CFS slows down when they are upright.

The researchers looked at the effect of a 60 degree tilt compared to the result when the individuals were supine (flat). HUT=Head Up Tilt.

They looked at 5 different cognitive tests. The tests are more demanding as n increases (from left to right). They looked at how long it took to give an answer.

If you look at the healthy people in the top graph, there is no difference whether the individual was flat or upright.

However, if you look at the CFS patients (bottom graph), when they were upright their results were statistically worse (notice the stars) for n=2, n=3 and n=4 (and the gap increased as the task became more difficult).

 

[Kati]

This figure shows evidence that the thinking of people with ME/CFS slows down when they are upright.

The researchers looked at the effect of a 60 degree tilt compared to the result when the individuals were supine (flat). HUT=Head Up Tilt.

They looked at 5 different cognitive tests. The tests are more demanding as n increases (from left to right). They looked at how long it took to give an answer.

If you look at the healthy people in the top graph, there is no difference whether the individual was flat or upright.

However, if you look at the CFS patients (bottom graph), when they were upright their results were statistically worse (notice the stars) for n=2, n=3 and n=4 (and the gap increased as the task became more difficult).


View attachment 8608

@Dolphin what does 'n' represent? (I'm a bit slow and reclining...)

 

[Valentijn]

@Dolphin what does 'n' represent? (I'm a bit slow and reclining...)

Cognitive tests, with each higher number being a more difficult one.

 

[Marky90]

http://www.cortjohnson.org/blog/201...ops-orthostatic-intolerance-mecfs-next-steps/

This just seems awesome? But im no expert, what do you guys think?

 

[SDSue]

I thought this looked exciting, too, but it seems to me phenylephrine is just like Midodrine (which is commonly used for POTS) - another alpha 1-adrenergic agonist.

Did I miss something? I sure hope so!

 

[Gingergrrl]

Is phenylephrine a new prescription med or something in trials? How does it differ from Midodrine and Droxidopa? Just to make sure, is it different from Ephedrine based things that actually cause tachycardia?!!!

 

[ahimsa]

@Marky90, thanks for posting the link to that article!

I have not yet read the article about the research but I think any new research on OI in ME/CFS is a good thing. And this was done by a well known doctor, Dr. Julian Stewart.

@Gingergrrl, I'm pretty sure phenylephrine is an over the counter drug, not a prescription. It's a decongestent but it is not the same as pseudoephedrine (generic Sudafed). Someone please correct me if this is wrong.

 

[meeKO]

My wife just started taking phenylephrine but it hasn't had much impact on her OI or POTS or NMH. She'll keep on it for abit but this week we're re-trying to find something that makes a difference.

 

[SDSue]

I can't find the reference, but if memory serves they used IV phenylephrine in this trial because oral had no effect. Does anyone know for sure?

@meeKO @ahimsa

 

[ahimsa]

I can't find the reference, but if memory serves they used IV phenylephrine in this trial because oral had no effect. Does anyone know for sure?

@meeKO @ahimsa

Hi @SDSue,

I don't have access to the full article. I did read the abstract (tried to!) and it did not say--unless I missed it, which is entirely possible.

My earlier post on this thread was just the result of googling the drug name. I thought I recognized that drug (I generally buy generic, not brand name) but I wanted to make sure it was the one I was thinking about.

Sorry, but that's all I got! I have no actual expertise!

 

[Forbin]

This kind of failure to respond correctly to variations in CO2 levels is also at the heart of central sleep apnea (as opposed to obstructive sleep apnea). I'm not sure how common central sleep apnea is among ME patients, but it seems consistent with a general pattern of faulty system regulation..

 

[meeKO]

I can't find the reference, but if memory serves they used IV phenylephrine in this trial because oral had no effect. Does anyone know for sure?

@meeKO @ahimsa

I haven't done any reading I'm afraid but I could believe it as the over the counter Sudafed PE doesn't seem to be helping even combined with Deralin (Propranolol hydrochloride)...

 

[valentinelynx]

I haven't done any reading I'm afraid but I could believe it as the over the counter Sudafed PE doesn't seem to be helping even combined with Deralin (Propranolol hydrochloride)...

Phenylephrine is mostly ineffective when taken orally. The marketing of it as a substitute for pseudoephedrine is pretty much a scam. We use in the anesthesia to raise blood pressure all the time (very old drug). Problem is it only lasts about 5-10 minutes. So I doubt it would be useful as a treatment for OI. Therefore, this study would be useful only as demonstrating a principle not as a discovery of a new treatment drug.