Early Cerebral Hypoperfusion .. with OI Without Tachycardia During .. Tilt Test is Independent of Vasovagal Response, 2021, González-Hermosillo et al

Abstract
Background: Cerebral hypoperfusion before syncope has been shown in patients with chronic orthostatic intolerance (OI) without tachycardia, but it is unknown if an initial decrease of cerebral blood flow velocity (CBFv) could be related to the vasovagal response (VVR) to head-up tilt test (HUTT).

Objective: The objective of the study was to compare cardiovascular, cerebrovascular, and autonomic variables during HUTT in OI patients with or without a VVR.

Methods: We included 74 subjects (58% female, mean age 33 ± 12 years) who underwent a 30-min HUTT and were divided into three groups: OI with VVR positive (VVR+), OI without VVR negative (VVR-), and asymptomatic healthy subjects with negative HUTT (control group). Cardiovascular, cerebrovascular, and autonomic variables were assessed beat-to-beat during HUTT with a Task Force monitor and a trans-cranial Doppler. Mean values were evaluated at baseline and throughout the first 10 min of tilting.

Results: Cardiovascular variables were similar in the three groups. Systolic, diastolic, and mean CBFv were similar in VVR+ and VVR-, but both groups had lower CBFv than the control group. Systolic and diastolic CBFv decreased from baseline since min 1 in VVR+ and VVR- and since min 5 in the control group. The mean CBFv had a significant decrease since min 1 compared to baseline in all groups. Spectral indices of heart rate and blood pressure variability showed a similar autonomic response to HUTT in all groups.

Conclusion: Patients with chronic OI without tachycardia have early postural cerebral hypoperfusion, regardless of the VVR during HUTT.

https://pubmed.ncbi.nlm.nih.gov/34129596/

 

Thank you @Mij for your post.

It appears the study you've posted, and the one I've added below both used Doppler technology.

Although ME isn't mentioned in the article you posted, IMO it seems there is some potential for reduced CBF to be considered a secondary biomarker for ME.

I'm saying secondary biomarker, as clearly, other conditions/diseases have reduced CBF.


In conjunction with your posting, I've been thinking about the following 2020 study on hypoperfusion and pwME.


Doubtless, this study was previously noted on this forum:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7044650/#__ffn_sectitle

- 429 pwME and 44 HC.

- during OI stress testing 90% of PwME showed CBF reduction.

I'm wondering if given technological advances, and increased knowledge and interest in OI, are we getting any closer to reduced CBF, and/or OI, as a secondary biomarker for ME?

A biomarker that doesn't stand alone, however given other necessary findings could diagnose patients with ME?

Here is the abstract for the 2020 study on hypoperfusion, pwME, vs. HC:


Clin Neurophysiol Pract. 2020; 5: 50–58.
Published online 2020 Feb 8. doi: 10.1016/j.cnp.2020.01.003
PMCID: PMC7044650
PMID: 32140630

Cerebral blood flow is reduced in ME/CFS during head-up tilt testing even in the absence of hypotension or tachycardia: A quantitative, controlled study using Doppler echography
C. (Linda) M.C. van Campen,a,⁎ Freek W.A. Verheugt,b Peter C. Rowe,c and Frans C. Vissera
Author information Article notes Copyright and License information Disclaimer


Abstract
Objective
The underlying hypothesis in orthostatic intolerance (OI) syndromes is that symptoms are associated with cerebral blood flow (CBF) reduction. Indirect CBF measurements (transcranial Doppler flow velocities), provide inconsistent support of this hypothesis. The aim of the study was to measure CBF during a 30 min head-up tilt test (HUT), using Doppler flow imaging of carotid and vertebral arteries, in individuals with chronic fatigue syndrome/myalgic encephalomyelitis (ME/CFS), a condition with a high prevalence of OI.

Methods
429 ME/CFS patients were studied: 247 had a normal heart rate (HR) and blood pressure (BP) response to HUT, 62 had delayed orthostatic hypotension (dOH), and 120 had postural orthostatic tachycardia syndrome (POTS). We also studied 44 healthy controls (HC). CBF measurements were made at mid-tilt and end-tilt. Before mid-tilt, we administered a verbal questionnaire to ascertain for 15 OI symptoms.

Results
End-tilt CBF reduction was 7% in HC versus 26% in the overall ME/CFS group, 24% in patients with a normal HR/BP response, 28% in those with dOH, and 29% in POTS patients (all P < .0005). Using a lower limit of normal of 2SD of CBF reduction in HC (13% reduction), 82% of patients with normal HR/BP response, 98% with dOH and 100% with POTS showed an abnormal CBF reduction. There was a linear correlation of summed OI symptoms with the degree of CBF reduction at mid-tilt (P < .0005).

Conclusions
During HUT, extracranial Doppler measurements demonstrate that CBF is reduced in ME/CFS patients with POTS, dOH, and even in those without HR/BP abnormalities.

Significance
This study shows that orthostatic intolerance symptoms are related to CBF reduction, and that the majority of ME/CFS patients (90%) show an abnormal cerebral flow reduction during orthostatic stress testing. This may have implications for the diagnosis and treatment of ME/CFS patients.

 

Thanks @Trish

ETA: I have trouble finding earlier threads and posts. I type in under the "Search" function, and am sometimes successful....