Cerebral blood flow is reduced in severe Myalgic Encephalomyelitis/Chronic Fatigue Syndrome patients during mild orthostatic stress testing: an exploratory study at 20 degrees of head-up tilt testing, by C (Linda) MC van Campen, Peter C Rowe  and Frans C Visser in Healthcare 2020, 8(2), 169, 13 June 2020 [doi.org/10.3390/healthcare8020169]  (This article belongs to the Special Issue ME/CFS – the Severely and Very Severely Affected)


Research abstract:


In a study of 429 adults with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), we demonstrated that 86% had symptoms of orthostatic intolerance in daily life. Using extracranial Doppler measurements of the internal carotid and vertebral arteries during a 30-min head-up tilt to 70 degrees, 90% had an abnormal reduction in cerebral blood flow (CBF).

A standard head-up tilt test of this duration might not be tolerated by the most severely affected bed-ridden ME/CFS patients. This study examined whether a shorter 15-min test at a lower 20 degree tilt angle would be sufficient to provoke reductions in cerebral blood flow in severe ME/CFS patients.

Methods and results:

Nineteen severe ME/CFS patients with orthostatic intolerance complaints in daily life were studied: 18 females. The mean (SD) age was 35(14) years, body surface area (BSA) was 1.8(0.2) m2 and BMI was 24.0(5.4) kg/m2. The median disease duration was 14 (IQR 5–18) years. Heart rate increased, and stroke volume index and end-tidal CO2 decreased significantly during the test (p ranging from <0.001 to <0.0001). The cardiac index decreased by 26(7)%: p < 0.0001. CBF decreased from 617(72) to 452(63) mL/min, a 27(5)% decline.

All 19 severely affected ME/CFS patients met the criteria for an abnormal CBF reduction.


Using a less demanding 20 degree tilt test for 15 min in severe ME/CFS patients resulted in a mean CBF decline of 27%. This is comparable to the mean 26% decline previously noted in less severely affected patients studied during a 30-min 70 degree head-up tilt.

These observations have implications for the evaluation and treatment of severely affected individuals with ME/CFS.

4.1. Clinical Implications

Patients are advised to lie down when they experience orthostatic intolerance complaints. Our findings of a clinically significant cerebral blood flow reduction at just 20 degrees suggest that a slight head-up position may not be adequate enough to resolve symptoms of orthostatic intolerance in some patients. Furthermore, the European Society of Cardiology syncope guidelines and other papers advocate the use of a nocturnal head-up position of more than 10 degrees to prevent nocturnal polyuria and the consequent circulatory underfilling [45,46,47,48]. In light of the presented results, this advice has the potential to be detrimental in some ME/CFS patients.

Health rising: Low Brain Blood Flows and Orthostatic Intolerance Ubiquitous in Chronic Fatigue Syndrome (ME/CFS), by Cort Johnson

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