Sitting Position Linked to Reduced Cerebral Blood Flow in Patients with Myalgic Encephalomyelitis

by Lauren Taylor from In The Cloud Copy

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating condition in which the affected patient has overwhelming fatigue that does not improve even after adequate rest. The symptoms of ME/CFS tend to worsen after both mental and physical activities. This is the most common symptom, but other symptoms include difficulty sleeping, concentrating, thinking, dizziness, and pain. People with this condition can not function in the way they did prior to their diagnosis, even though they likely do not appear to be ill.

Researchers wanted to study the effects and prevalence of orthostatic intolerance on patients with MC/CFS. Orthostatic intolerance is a condition in which a patient’s symptoms worsen when they enter and maintain an upright position and seem to improve when they enter a recumbent position.

Study Methods

Patients in the study were suspected of having ME/CFS. There were 801 patients enrolled in the study, conducted between June 2011 and January 2018. Patients were examined, all by the same clinician, to see if they met the criteria for a diagnosis of CFS/ME. The disease severity was also classified from mild to very severe. Symptoms (or lack thereof) of orthostatic intolerance in everyday life were also assessed. Some of these symptoms include nausea, prior syncope or near-syncope, and dizziness/light-headedness.

A sitting test was performed first which had patients in a seated position for at least one hour prior to testing beginning. Patients had measurements of their blood pressure and heart rate, as well as an extracranial Doppler echography completed. Once these measurements were completed, patients were then returned to a supine position for approximately 15 minutes, then each of these measurements were taken again.

Study Results

Of the 801 patients initially enrolled in the study, 53 of them did not meet the criteria for ME/CFS, leaving 748 patients in the study. 177 (24%) of those patients were classified as having severe ME/CFS. Further patients were excluded for varying reasons, ultimately leaving 100 patients with severe ME/CFS that were studied. Of these, 88 were female and 12 were male. The disease duration median in this group was approximately 14 years and orthostatic intolerance symptoms were reported as occurring at least daily in 90 of the 100 patients.

Results of the study showed that there was a notable reduction in the cerebral blood flow in patients with ME/CFS that was brought on by sitting, compared to healthy patients that had very minimal changes in the blood flow when sitting. For patients that recorded minimal or no daily orthostatic intolerance symptoms, there was very little reduction in the cerebral blood flow, which was similar to the healthy control patients. Patients with everyday orthostatic intolerance symptoms saw a 26.9% reduction in their cerebral blood flow while sitting.

This study has some clinical implications for patients. The results support the advice that patients need to rest when they start to display symptoms of orthostatic intolerance and that resting in a sitting position will likely not be adequate. They likely need to be in a non-sitting position in order to resolve the symptoms they are experiencing. Patients with severe ME/CFS must take into account that sitting is likely a big stressor for orthostatic intolerance symptoms.

Click here to check out the original study.

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