At the virtual annual meeting of the International Association for Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (IACFSME), speakers presented data showing similar pathophysiologic abnormalities in people with systemic symptoms associated with ME/CFS who had a prior SARS-CoV-2 infection and those who did not, including individuals whose illness preceded the COVID-19 pandemic.
Core clinical diagnostic criteria for ME/CFS established by the Institute of Medicine in 2015 include substantial decrement in functioning for 6 months or longer, postexertional malaise, or a worsening of symptoms following even minor exertion (often described by patients as “crashes”), unrefreshing sleep, and cognitive dysfunction and/or orthostatic intolerance that are frequent and severe.
Long COVID has been defined in several different ways using different terminology. The U.S. Centers for Disease Control and Prevention, for example, defines “post-COVID conditions” as those continuing four or more weeks beyond first symptoms. The World Health Organization’s clinical case definition of “post COVID-19 condition” includes otherwise unexplained symptoms 3 months from COVID-19 onset and lasting longer than 2 months.
Both ME/CFS and long COVID commonly involve numerous symptoms beyond the defining ones, affecting nearly every organ system in the body, including systemic, neurocognitive, endocrine, cardiovascular, pulmonary, musculoskeletal, and gastrointestinal, with wide variation among individuals. Autonomic dysfunction is common to both conditions, particularly postural orthostatic tachycardia syndrome (POTS).
“My way of understanding these illnesses is that they’re not just multisystem illnesses, but all these interactive systems that lean on each other are dysregulated. … I would say that a very common underlying mediator of both ME/CFS and long COVID is autonomic dysfunction, and it presents as POTS,” Nancy Klimas, MD, director of the Institute for Neuro-Immune Medicine at Nova Southeastern University, Fort Lauderdale, Fla., told this news organization.
Dr. Klimas, who is also director of Clinical Immunology Research at the Miami Veterans Affairs Medical Center, added that “if basic bioenergetics are disrupted and in an oxidative-stress state [then] they have downregulated energy production at the cellular level, which seems to be the case in ME/CFS and now in long COVID.”
New ICD-10 codes better characterize the syndromes
New ICD-10 codes for 2023, being implemented on Oct. 1, will enable clinicians to better document all of these interrelated conditions.
Under the existing G93.3, Postviral and related fatigue syndromes, there will now be:
- G93.31 – Postviral fatigue syndrome.
- G93.32 – Myalgic encephalomyelitis/chronic fatigue syndrome (and the separate terms).
- G93.39 – Other postinfection and related fatigue syndromes.
The old R53.82, “Chronic fatigue, unspecified” code now excludes all of the above conditions.
The additional code U09.9 for “post COVID-19 condition, unspecified,” may also be used if applicable.
In addition, a new code for POTS, G90.A, which wasn’t previously mentioned in ICD-10, may also be used starting Oct. 1.
Lucinda Bateman, MD, founder and director of the Bateman Horne Center, Salt Lake City, advises using all applicable codes for a given patient. “If a patient came into my office with long COVID and met criteria for ME/CFS, we would code both, and also any other syndrome criteria that they may meet, such as POTS or fibromyalgia.
“If people use the codes appropriately, then you can understand the overlap better. It increases the likelihood of reimbursement, creates a more accurate medical record for the patient, and provides them with a better tool should they require disability benefits.”
Dr. Bateman advises in-office orthostatic evaluation for all patients with this symptom constellation, using a passive standing evaluation such as the 10-minute NASA Lean test.
“Clinicians should take the time to do orthostatic testing in these patients because it provides objective markers and will help lead us to potential interventions to help improve people’s function.”
The Bateman Horne center offers clinician resources on management of ME/CFS and related conditions.