New NIH Study Explores PEM Symptoms in ME/CFS


For patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), post-exertional malaise (PEM) can be extremely debilitating and disruptive. PEM occurs when symptoms worsen or become more severe within 12-48 hours of either physical or mental exhaustion. In a recent groundbreaking study, supported by the NIH Intramural Program, patients with ME/CFS spoke directly about the difficulties of dealing with PEM. Check out the full findings published in Frontiers of Neurology.

Myalgic Encephalomyelitis / Chronic Fatigue Syndrome (ME/CFS)

Referred to as either myalgic encephalomyelitis (ME) or chronic fatigue syndrome (CFS), this condition is chronic, complicated, and rare. Doctors are not sure what causes ME/CFS. However, hypotheses include genetics, viral infections, hormonal imbalances, or immune function issues. ME/CFS causes severe, unexplained fatigue that does not improve with rest. Some patients experience PEM, which worsens after physical or mental activity. In fact, according to the CDC:

For some patients, even daily chores and activities such as cleaning, preparing a meal, or taking a shower can be difficult and may need to be broken down into shorter, less strenuous pieces. While vigorous aerobic exercise can be beneficial for many chronic illnesses, patients with ME/CFS do not tolerate such exercise routines.

While ME/CFS can affect people of all ages, it more often affects women and those between ages 30-50. Symptoms vary in severity. Additionally, patients may experience periods of extreme symptoms and periods of remission. Symptoms include:

  • Dizziness
  • Difficulty concentrating
  • Blurry vision
  • Swollen lymph nodes
  • Low stamina
  • Depression or anxiety
  • Heart palpitations
  • Muscle and joint pain
  • Sleep problems
  • Excessive sleepiness
  • Severe fatigue that inhibits daily activities
  • Headache
  • Sore throat

Learn more about ME/CFS here.

Uncovering PEM

Admittedly, doctors and researchers are unclear about the biological backing of PEM. So researchers at the National Institute of Neurological Disorders and Stroke (NINDS) wanted to get patient input on how PEM actually impacted them. While surveys can be helpful in uncovering information, the NINDS decided to instead pursue in-depth discussions with patients to get a more nuanced and well-rounded perspective on the intersection of PEM and quality-of-life (QOL).

The study included 43 patients with ME/CFS. These patients were involved in 9 focus groups discussing PEM, what caused it, and how they handled it. In addition to learning about PEM, researchers hope to better understand the progression of ME/CFS as a whole.

Researchers discovered:

  • PEM can be brought on by cardiopulmonary exercise tests (CPETs), which are often on a stationary bike.
  • Generally, PEM symptoms involve confusion and cognitive difficulties, muscle pain and weakness, and extreme fatigue. However, additional symptoms included increased sensitivity to light and sound, nausea, headache, and a sore throat.
  • While some PEM symptoms only last for 24 hours, they can last for weeks.
  • Symptoms caused by CPETs were often more intense, had a faster onset, and lasted longer than PEM symptoms caused by daily activities like showering, shopping, or visiting friends.
  • Many patients required a dark room and complete rest, with no movements, to lower symptoms.
  • It can be difficult to plan ahead for activities because symptoms can occur without warning.

Read the source article here.

Jessica Lynn

Jessica Lynn

Jessica Lynn has an educational background in writing and marketing. She firmly believes in the power of writing in amplifying voices, and looks forward to doing so for the rare disease community.

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