Autonomic dysfunction in myalgic encephalomyelitis and chronic fatigue syndrome: comparing self-report and objective measures, 2019, Sunnquist et al

[Andy]

Dear Editors:

Myalgic encephalomyelitis (ME) and chronic fatigue syndrome (CFS) have debilitating impacts on affected individuals. Core symptoms include post-exertional malaise, neurocognitive challenges, and sleep dysfunction [1]. Additionally, a significant minority of patients experience autonomic symptoms, including orthostatic intolerance, gastrointestinal disturbances, and circulation issues [2].

Several case definitions for ME and CFS require the presence of autonomic dysfunction for diagnosis [2], while other researchers have proposed an “autonomic dysfunction” subtype of ME and CFS [3]. Identifying the appropriate measures of autonomic symptomatology for individuals with ME and CFS will further contribute to understanding the role of the autonomic system in this illness.

Pay wall, https://link.springer.com/article/10.1007/s10286-019-00615-x
Sci hub, https://sci-hub.se/10.1007/s10286-019-00615-x

 

[Trish]

The aim of the study reported here was to extend upon this body of literature by examining the association between HRV and autonomic items from another self-report measure, the DePaul Symptom Questionnaire (DSQ)
.....

All participants (n=141) met the Fukuda et al. (1994) criteria for CFS [9]. After completing the DSQ, participants underwent a battery of autonomic tests...

In addition to providing evidence for the construct validity of DSQ items, this fnding of accurate self-reporting of autonomic symptoms by individuals is signifcant in that previous studies have found that individuals with ME and CFS often face de-legitimization by physicians and loved ones [10]. Validating the individual’s self-reported symptoms using objective data, such as HRV, may help in reducing stigma towards individuals with ME and CFS.

 

[Snow Leopard]

Finally, the LF:HF ratio was negatively correlated with self-reported nausea. The remaining correlations were not signifcant.

The study also stated the (oversimplified and partially misleading, but common) assumption that:

HRV can be divided into two major components, the low-frequency (LF) component, indicative of sympathetic dominance, and the high-frequency (HF) component, indicative of parasympathetic dominance.

and

The LF:HF ratio is an indicator of balance between the sympathetic and parasympathetic systems.

I think it it's a waste of time trying to associate HRV measures with self-report measures since the biggest predictor of altered (reduced) HRV (compared to average population controls) is cardiovascular deconditioning. It also doesn't suggest anything specific in regards to treatment (or measuring treatment response).