Coronavirus Causes Long Term Problems?
Neurological manifestations of COVID-19 may be relatively common. 78 out of 214 patients in one hospital study, or 36%, had neurological symptoms, most commonly muscle injury and loss of consciousness, but also a few cases of stroke.
There was a case study of a 62-year-old man in Wuhan who presented with oculomotor nerve palsy and whose throat swab tested positive for 2019-nCOV.
Other possible causes of nerve palsy, such as stroke, diabetic neuropathy, brain tumor, and Guillain-Barre syndrome were ruled out, so his doctors hypothesized that the virus caused the nerve failure.
Another case of COVID-19, in Beijing, was confirmed to contain the virus in cerebrospinal fluid. This was the first case of viral encephalitis due to COVID-19.
There is evidence that COVID-19 can infiltrate the central nervous system and evidence that neurological symptoms are common during COVID-19 infection. But it is not yet clear whether the neurological symptoms are caused by the virus infiltrating nerve and muscle tissue, by other organ damage, by the treatments for COVID-19, or by the body’s inflammatory response.
SARS, an earlier coronavirus epidemic, did frequently cause long term problems.
Out of 233 formerly hospitalized SARS survivors in one follow-up study, 27.1% met the criteria for chronic fatigue syndrome, 40% had a psychiatric disorder, and 40% mentioned a chronic fatigue problem. Only 3%, by contrast, had a psychiatric disorder before contracting SARS; this indicates that SARS may have caused psychiatric problems. (Note that the most common psychiatric disorder was post-traumatic stress disorder.)
Half of SARS survivors who were hospitalized experienced mild reduction in pulmonary function even 3 months after being discharged from the hospital. 30-45% of survivors had bone necrosis in their hips or knees that likely resulted from the long-term use of corticosteroids in treating SARS.
SARS was found in one case to infiltrate the cerebrospinal fluid, causing seizures.
Neurological symptoms were uncommon but possible in SARS. Out of 664 SARS patients in Taiwan, eight (1%) were found to have neurological disorders including neuropathy, myopathy, and rhabdomyolysis. 5 out of 206 SARS patients in Singapore, or 2%, had strokes, while none had risk factors for strokes.
This may result from SARS, like some other viral infections, causing a hypercoagulable state. These neuromuscular symptoms look similar to the ones observed in COVID-19.
It is reasonable to suppose that COVID-19, like SARS, can increase the risk of stroke and cause chronic nerve disorders in a few percent of patients.
Though we do not yet know whether COVID-19 causes chronic fatigue, there is a plausible mechanism: virus-induced immune dysfunction.
COVID-19 patients have diminished T-cell levels and more severe cases have a larger reduction. 75% of 522 COVID-19 patients from a Chinese hospital had low T-cell levels, with the lowest levels found in the oldest patients. Inflammatory cytokine levels (IL-6, IL-10, and TNF-alpha) was negatively correlated with T-cell count and positively correlated with the severity of the disease.
This is consistent with the “cytokine storm” phenomenon, in which a spike of inflammatory cytokines is responsible for the Acute Respiratory Distress Syndrome (ARDS) and Multiple Organ Dysfunction Syndrome (MODS) which occur in severe and deadly cases of respiratory infections, including COVID-19, SARS, and H5N1. This opens the door to a mechanism by which COVID-19 could cause long-term immune system dysregulation if T-cell levels do not go back to normal after a patient recovers.
In conclusion, it seems likely that a high percentage of hospitalized COVID-19 patients, like SARS patients, may develop symptoms of chronic fatigue syndrome, and that a low percentage may develop chronic nerve damage.
Written by Sarah Constantin
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