Chronic Fatigue Syndrome (ME/CFS): What a Neurologist Looks For

Exhaustion that a full night's sleep does not touch, and that worsens after ordinary activity, is not the same as being tired. It may be myalgic encephalomyelitis, also called chronic fatigue syndrome (ME/CFS), a long-term illness involving the nervous system, the immune system, and energy metabolism.

Why a neurologist

The World Health Organization classifies myalgic encephalomyelitis under diseases of the nervous system, and much of what patients live with is neurological: cognitive impairment, disturbed sleep, pain, sensory sensitivity, and difficulty keeping blood pressure and heart rate stable when upright, a form of autonomic dysfunction.

The 2015 Institute of Medicine report estimated that 836,000 to 2.5 million Americans have ME/CFS and that an estimated 84 to 91 percent have not yet been diagnosed. Many spend years being told their tests are normal, which is true and beside the point. A neurologist's job is to check for the conditions that mimic it, several of which have their own treatment, and then to name the illness so that treatment can start.

Symptoms of chronic fatigue syndrome

The 2015 diagnostic criteria require the first three, plus at least one of the last two:

1. A substantial drop in what you can do, lasting more than six months, of new or definite onset rather than lifelong, with fatigue that rest does not relieve
2. Post-exertional malaise
3. Unrefreshing sleep
4. Either cognitive impairment, or orthostatic intolerance, meaning symptoms that worsen on standing and settle on lying down

The criteria add one more stipulation: the diagnosis should be questioned if the symptoms are not present at least half the time, at moderate or worse intensity.

Also common: muscle and joint pain, new headaches, tender lymph nodes, digestive problems, sensitivity to light and sound, dizziness on standing, and burning or tingling in the hands and feet from small fiber neuropathy.

Tired, or post-exertional malaise?

Post-exertional malaise is the hallmark, and it is what separates ME/CFS from ordinary tiredness. Being tired is proportionate: a hard day makes you sleepy, and a night's sleep restores you. Post-exertional malaise is a worsening of all your symptoms, not just fatigue, after physical, mental, or emotional exertion that would once have been easy. The crash typically arrives 12 to 48 hours later, not immediately, so the trip to the store on Tuesday is paid for on Thursday. It can last days or weeks, and rest does not shorten it. If you recognize that delayed pattern, it is the most useful thing to tell us.

Headaches and dizziness in ME/CFS

Headaches and dizziness are common enough in ME/CFS that they deserve their own evaluation rather than being filed under the illness. New or worsening headaches often follow a migraine pattern and respond to migraine treatment. Dizziness, lightheadedness, and a racing heart on standing usually reflect orthostatic intolerance, including POTS, which has its own treatments. Both are worth measuring, because they are among the most treatable parts of the illness.

Causes and risk factors

The cause is not known. Several threads run through the research: a triggering viral illness such as Epstein-Barr virus or COVID-19, which many patients can name precisely; immune dysfunction and low-grade neuroinflammation; impaired energy production in cells; autonomic and hormonal dysregulation; and a genetic susceptibility under study.

ME/CFS is diagnosed more often in women and usually begins in early to middle adulthood, though it can start at any age. Fibromyalgia, migraine, and sleep disorders frequently travel with it.

Diagnosis, and what has to be ruled out first

No test confirms ME/CFS. The diagnosis comes from the history, after other conditions that produce the same symptoms have been excluded. That is where a neurologist earns their keep, because several of the look-alikes have their own treatment.

A normal set of results does not mean nothing is wrong. It means the common causes are excluded and the diagnosis now rests on your symptom pattern, which is how ME/CFS is diagnosed everywhere.

Visual guide

Looking for treatable look-alikes

• Pattern: The history includes exertional crashes and unrefreshing sleep.
• Other causes: Sleep apnea, anemia, thyroid disease, and other problems are considered.
• Plan: Care follows the findings and the person's symptom limits.

Treatment

There is no cure, but symptoms can be managed and daily life improved.

• Pacing. Learning your energy limits and staying inside them so you stop triggering crashes. In practice it means finding the level of activity you can sustain without a crash the next day, spreading tasks out with rest before you feel you need it, and treating a good day as a day to hold steady rather than catch up. A symptom and activity diary is how most people find their limits, and it is a skill we teach rather than an instruction to rest.
• Sleep. Treating insomnia or sleep apnea and holding a consistent schedule.
• Orthostatic symptoms. Fluids, salt, compression garments, and medication when standing is a major problem.
• Pain and headaches. Migraine-directed treatment when headaches fit that pattern, and medication and non-drug approaches for muscle and joint pain.
• Support and rehabilitation. Physical therapy with someone experienced in ME/CFS, working inside your limits, plus support for the strain of chronic illness. We do not provide therapy in our office and refer you out for it.

Visual guide

Understanding pacing

• Exertion: Physical or mental activity can trigger a later symptom crash.
• Rest: Sleep may feel unrefreshing.
• Pacing: Activity is adjusted to the person's limits and symptoms.

How long does chronic fatigue syndrome last?

Honestly, a long time for most people, and the course fluctuates. ME/CFS is usually a chronic illness with better and worse periods rather than a steady decline. A systematic review found a median full recovery rate of about 5 percent in adults, while about 40 percent improved. Children and adolescents do better: in one large cohort 38 percent reported recovery by five years and 68 percent by ten. Improvement is likelier when crashes are avoided early and the treatable pieces, such as sleep apnea, orthostatic intolerance, and migraine, are found and treated. No test predicts an individual's course, which is one more reason to manage the illness actively rather than wait it out.

What an evaluation here involves

See a neurologist if severe fatigue has lasted more than six months, if activity reliably causes a crash a day or two later, if sleep does not refresh, or if brain fog, dizziness, or a racing heart on standing are part of it.

A first visit with Dr. Achillefs Ntranos, MD is 60 minutes, which is what it takes to hear how the illness started and what a bad day looks like. It includes a neurological examination and, where orthostatic symptoms are part of the story, heart rate and blood pressure lying and standing. Blood tests, a home sleep study, and a skin biopsy follow when the history points that way. Most of the evaluation is history, which works well by video, so you can request a visit in Beverly Hills or Los Angeles, or by video anywhere in California.

References

1. Institute of Medicine. Beyond Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Redefining an Illness. National Academies Press, 2015.
2. Centers for Disease Control and Prevention. Symptoms of ME/CFS.
3. National Institute for Health and Care Excellence. Myalgic encephalomyelitis (or encephalopathy)/chronic fatigue syndrome: diagnosis and management (NG206), 2021.
4. World Health Organization. ICD-10 G93.3, Postviral fatigue syndrome (benign myalgic encephalomyelitis).
5. Institute of Medicine. Box 7-1: proposed diagnostic criteria for ME/CFS. National Academies Press, 2015.
6. National Institute for Health and Care Excellence. NG206 recommendations, including energy management and physical activity, 2021.
7. Cairns R, Hotopf M. A systematic review describing the prognosis of chronic fatigue syndrome. Occupational Medicine, 2005.
8. Rowe KS. Long term follow up of young people with chronic fatigue syndrome attending a pediatric outpatient service. Frontiers in Pediatrics, 2019.