In the fourth and final installment of his follow-up to our July 16 webinar, Dr. Peter Rowe, director of the Chronic Fatigue Clinic at Johns Hopkins Children’s Center, responds to patients’ questions on the intersection of PEM and OI and exercise intolerance with OI. To view the recording of the full webinar, go to our YouTube channel here. To sign up for future blog updates, go here.
Q: Do you think that people with ME/CFS who have problems being upright should be tested for OI as standard procedure? If so, how can we make this happen? How can we educate clinicians about this?
Even in the most impaired individuals with ME/CFS, a minimal evaluation should include assessment of the frequency of orthostatic symptoms, as well as measurement of heart rate and blood pressure supine and sitting. Some very impaired people with ME/CFS may not tolerate standing or tilt testing (Miwa K. Cardiac dysfunction and orthostatic intolerance in patients with myalgic encephalomyelitis and a small left ventricle. Heart Vessels 2014). For the vast majority of those with ME/CFS, some form of orthostatic testing (whether tilt testing or 10 minutes of standing) is likely to be informative and to help determine whether treatment of orthostatic intolerance is warranted. Similar assessment of the ability to tolerate upright posture and to maintain a normal heart rate and blood pressure after several minutes of standing is worth considering as part of the differential diagnosis of the symptom of chronic fatigue.
–During the CDC CFS Patient-Centered Outreach and Communication Activity (PCOCA) Conference Call in 2013 (transcript here), Dr. Nancy Klimas said:
We use the bike exercise test to challenge the autonomic system and we found by a peak of exercise of eight minutes they are already releasing inflammatory cytokines. These cytokines will then go to affect a host of other things, so that at the end of the day you have pain, oxidative stress, endocrine regulatory defects, energy problems and inflammation. The first step in relapse is the autonomic challenge and the second step is the inflammatory result.
A: There are now several papers showing a variety of gene expression changes after exercise, most notably the work by the Light group at the University of Utah. The autonomic nervous system influences many of the interactions between the nervous system and the immune system (for a detailed review see: Kenney M.J., Ganta C.K. Autonomic Nervous System and Immune System Interactions. Comprehensive Physiology 4: 1177-1200, 2014). As a result, it is reasonable to hypothesize that there are changes in cytokine release in response to tilt testing or other forms of orthostatic stress, not unlike the changes following exercise.
A related point is worth mentioning as we discuss the interactions of different biological systems. In an elegant study that I believe has not received enough attention, Dr. David Jardine and colleagues (American Journal of Cardiology 1999; 79: 1302-6) showed that those with recurrent syncope have a marked increase in the release of ACTH and cortisol during tilt table testing compared to controls. These changes in ACTH and cortisol would be expected, in turn, to have important consequences for the immune system. As far as I am aware, this kind of study has not been attempted in those with ME/CFS, but might shed further light on autonomic and neuroendocrine interactions in this illness.
The next webinar will be held Oct. 15 with Dr. Alan Light. Check solvecfs.org/webinar for registration details.