By Lauren Taylor from In The Cloud Copy
COVID-19 has flooded headlines daily since it first reared its head in late 2019 and early 2020. Some parts of the world were hit much harder than others and some are still struggling to control the virus. Doctors in Italy, one of the hardest hit areas, have found a possible connection between COVID-19 and myasthenia gravis, after three patients were diagnosed with the neurological condition.
Myasthenia gravis (MG) is an autoimmune neuromuscular disease that is characterized by sudden weakness in the skeletal muscles that are typically under your voluntary control. This sudden weakness is caused by a breakdown in the communication that normally occurs between the muscles and the nerves. The breakdown in communication is due to the blocking of signals that are typically transmitted from nerves to muscles. The signal blocking is caused by antibodies binding to molecules at the postsynaptic membrane of the neuromuscular junction.
In more than 50% of those diagnosed with myasthenia gravis, the first symptom or sign that they are developing the condition is eye involvement, including drooping of the eyelids, double vision, or other eye muscle symptoms. Approximately 15% of people develop face or throat muscle symptoms as their first symptom of the condition. Neck and limb muscle involvement is also often seen.
COVID-19 and Myasthenia Gravis
The patients who were studied who were discovered to have MG after COVID-19 infection were all located in Italy. The patients had an age range of 64 to 71, two of them being male, one being female. All three patients were free of any neurologic or autoimmune disorders prior to their COVID-19 diagnosis. All three of the patients had positive AChR-antibodies, the antibodies responsible for MG in some cases. Symptoms of MG appeared anywhere from 5 to 7 days after fever onset in the patients.
The patients all recovered after standard treatments for MG were administered. The first patient was treated with both prednisone and pyridostigmine bromide and showed a positive response to these typical treatments. The second patient was treated with one cycle of IV immunoglobulin and showed improvement. Both of these patients showed facial nerve deficit, while the second patient also showed ulnar nerve involvement.
The third patient needed mechanical ventilation after they developed respiratory failure and dysphagia. This patient was treated with plasmapheresis treatment and showed improvement.
All three of these patients showed onset of symptoms of MG approximately 5 to 7 days after onset of fevers, which is in line with other timelines for neurologic conditions that are often triggered by infections.
Researchers are still studying the possible correlation between COVID-19 infection and the development of myasthenia gravis. They did offer a possible explanation, saying that the antibodies that are typically aimed at the COVID-19 proteins may have some cross-reaction with the AChR antibodies. An alternative explanation stated that an infection with COVID-19 may just make the persons immunologic self-tolerance lower, leading to a greater chance of MG. More research is necessary of course before it can be said for certain that there is a positive correlation.
Check out the original study here.
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