Not an illness; reportedly, cats average about 15 hours of sleep a day, divided into numerous bouts of deep sleep or light dozing. Kittens and seniors, as much as 20 hours.
Spring, 1987: some virus was going around our office, friend circle, friends of friends in the Washington, D.C., area, and seemingly, society at large.
At first it seemed like just a mild cold. Unknowingly, I caught it from my supervisor in our poorly ventilated "glass box" office tower. That weekend while traveling with my BF I began to feel ill. It didn't seem very bad, or we would have cut our trip short. The next week I had to phone in sick.
Symptoms were still not extreme, except that I felt SO TIRED. Every morning I would stagger out of bed, phone in sick again, drink coffee, and sit in the kitchen the rest of the day -- unable to muster enough energy to get dressed, cook anything, read the paper, or even go back to bed.
Let alone get to a medical appointment.
In an oak tree, outside the kitchen window of the second-floor walk-up, a pair of woodpeckers were drilling a nest hole. I watched them all day, every day, in a sort of trance state that was actually frightening. If I'd had enough energy to be scared.
Meanwhile, my BF had caught whatever it was from me and was also suffering from bad fatigue, though not quite so acutely. In phone calls he reported on friends, and friends of friends, also afflicted. News media were calling it "yuppie flu," a case of spoiled entitlement, or mass hysteria.
After two weeks sick leave I managed to drag myself back to the office. But for much longer I strugged on with fatigue and weakness that made daily life more difficult.
Months later my BF and I still were experiencing "heavy knees," as we called it; aching and weakness in the legs when walking any distance. For that to resolve took a full year.
One of my BF's own friends among those struck, still disabled after so many months, broke off his engagement.
The "yuppie flu" would later, against much resistance, be recognized by most medical practitioners as chronic fatigue syndrome (or in the U.K., myalgic encephalitis) -- a physical illness. (Though some holdouts persist even now.)
…
Persistent neuroinflammation has been shown to factor in long covid, Alzheimers disease, and other chronic conditions.
According to researchers Diego E. Rincon-Limas and Aaron N. Johnson, writing recently in The Conversation,
Neuroinflammation results when your central nervous system – the brain and spine – activates its own immune system to protect itself against infection, toxins, neurodegeneration and traumatic injury. Neuroinflammatory reactions primarily occur in the brain. But for unknown reasons, patients also experience many symptoms outside the central nervous system, such as debilitating fatigue and muscle pain.
Based on research with fruit flies and mice, the two scientists and their team found the cascade of consequences producing pain and feeling of exhaustion doesn't directly damage muscles. Instead,
...the brain produces high levels of cytokines – chemicals that activate the immune system – that are released into the body. When these cytokines travel to muscles, they activate a series of chemical reactions that disrupts the ability of the powerhouse of cells – mitochondria – to produce energy.
...[T]his pathway directly causes fatigue.
(emphasis added)
And over a longer term, wouldn't it make sense that depriving muscles of energy would result in deconditioning, actual weakness, and even muscle wastage?
Extraordinarily, they discovered the same mechanism in the evolutionarily distant classes of insects and mammals.
The scientists note:
Since we studied the brain-muscle axis only in the context of simplified models, we don’t know whether it applies to more complex conditions such as fibromyalgia or chronic fatigue syndrome. We also don’t know how impaired energy production in muscles correlates with impaired energy production in the brain.
Most interesting of all, their discovery hints at a possible new treatment pathway. Antibodies that neutralize the cytokines in question are being tested in animals.
In addition, preparations are under way for clinical tests to try and sort out the possible roles in long covid of cytokines and lingering viral particles.
If this pans out, it could be an immense advance in quality of life of many millions.
Reportedly, at least 65 million people around the globe currently suffer from long covid, even more than the estimated 50 million who have Alzheimers.
It's also been estimated that 5% of the world's population has fibromyalgia with chronic fatigue syndrome perhaps afflicting another 1.3%. Women are particularly vulnerable.
The economic impact also is significant.
...
Coda: Ten years after my episode of CFS, I sustained a sports injury that developed into frozen shoulder and then a temporarily disabling case of fibromyalgia. Much worse than the chronic fatigue experience, the FM caused excruciating pain and muscle spasms throughout the body. I was fortunate to recover after a full year of combined medication, rest, physical therapy, and carefully graduated exercise. Other people who contracted FM have not been so lucky...including two members of my family, one of whom uses a wheel chair to this day.
At the time I was going through this, a problem with mitochondrial function was among the suspected causes. In line with the recent research.
For my memory and the record, news coverage from the time of the nearly-forgotten "yuppie flu" epidemic. Sorry that the first two are paywalled.
NYT, July 28, 1987
WaPo, June 30, 1987
Retrospective on early news coverage, via PubMed:
"Early epidemiologic studies, which relied upon flawed sampling methods, found the illness to primarily occur in middle- to upper-class white women, which led to use of the stigmatizing term 'yuppie flu' to describe CFS. This marks a clear instance of the 'conveyor belt' phenomenon, wherein highly reputable outlets like Newsweek and The Washington Post wrote pieces with stigmatizing headlines such as 'Yuppie Flu – The Fatigue That Never Ends.' These headlines were then recycled by several other media outlets, thus influencing public opinion of the illness, perpetuating the notion that people with CFS are weak-willed or suffering from psychosomatic illness."