Myalgic encephalomyeltis/chronic fatigue syndrome (ME/CFS) is an illness that affects nearly 0.5% of the general population. The history of chronic fatigue syndrome is interesting and the illness wasn’t identified or named until fairly recently, but similar symptoms presented as early as the 1860s. It is characterized by profound fatigue lasting at least six months and accompanied by numerous somatic symptoms. Although multiple biological and psychological mechanisms for ME/CFS have been investigated, a unifying disease concept is still lacking. In particular, little is known about the underlying neural mechanisms which initiate and chronically sustain fatigue.
Chronic fatigue has been linked to aberrant autonomic nervous system activity involving the hypothalamic-pituitary-adrenal axis, pain-related pathways, and abnormal brain activity. Brain areas commonly associated with mental fatigue include the parietal, cingulate, inferior frontal and superior temporal cortices, and the cerebellum and have been reported in patients with ME/CFS as well as multiple sclerosis, Parkinson’s disease, and cancer. These brain regions are known to contribute to cognitive function, including working memory.
Although abnormal neural mechanisms are critically important for this disabling syndrome, many different factors can initiate and perpetuate ME/CFS. Some of the epidemiological data strongly suggest that acute or chronic infections may be responsible, but chronic fatigue has also been reported in patients with cancer, auto-immune diseases, metabolic diseases, congestive heart failure, pulmonary diseases, etc. Our lab is focused on the neural mechanisms of fatigue because better understanding these abnormalities may help improve or abolish ME/CFS related fatigue in the future. The video shown below has some of our recent research findings related to brain connectivity in individuals with ME/CFS.
The History of Chronic Fatigue Syndrome
Symptoms similar to what is now known as ME/CFS have been around for a long time. Back in the 1860s, an illness called “neurasthenia” was characterized by tiredness, headaches, and insomnia. In the 1930s, epidemics of neuromyasthenia/ atypical poliomyelitis was characterized by similar symptoms. In the 1980s, there was an outbreak in Lake Tahoe, where an estimated 160 residents came down with these symptoms. These symptoms were later identified as ME/CFS. Two epidemiologists from the CDC were initially sent to investigate this outbreak, but were suspicious that the symptoms were related as they varied among the patients. Most had fatigue and joint pain, but some experienced light sensitivity, hair loss and memory problems. The epidemiologists believed the epidemic was exaggerated and possibly due to a psychological cause rather than a physical one.
Their article furthered the stigma against patients with these symptoms, but after they published the report, people all over the country with similar symptoms began to contact the doctors in Lake Tahoe. There have since been other outbreaks in New York, Northern California and North Carolina. Many researchers believe these outbreaks may be due to the Epstein-Barr Virus or other viruses that send the body’s defenses and immune system into overdrive. The major health agencies today recognize that ME/CFS likely has a biological origin as hundreds of studies have found biological abnormalities. The dominant theory is that there is not a single cause for ME/CFS, most individuals recover from the Epstein-Barr virus without these long-lasting symptoms.