A small study of patients with persistent symptoms long after a bout of COVID-19 found that nearly 60 percent developed nerve damage that may have been caused by a faulty immune response, a finding that may point to new treatments, the researchers found.
The new US study involved in-depth testing of 17 people with so-called prolonged COVID-19, a condition that appears within three months of infection with COVID-19 and lasts at least two months.
Dr. Ann Louise Oakland, a neurologist at Massachusetts General Hospital and lead author on the study said: Published in Neurology: Neuroimmunology & Neuroinflammation.
It is believed that up to 30 percent of people infected with COVID-19 develop prolonged COVID-19, a condition with symptoms ranging from fatigue, rapid heartbeat, shortness of breath, cognitive difficulties, chronic pain, sensory abnormalities, and muscle weakness.
Auckland and colleagues focused on patients with symptoms consistent with a type of nerve damage known as peripheral neuropathy. All but one of them had mild cases of COVID-19, and none of them had nerve damage prior to infection.
After ruling out other possible explanations for the patients’ complaints, the researchers performed a series of tests to determine if nerves were involved.
“We looked with every major objective diagnostic test,” Oakland said. The vast majority had microfiber neuropathy, which means damage to the small nerve fibers that detect sensations and regulate involuntary bodily functions such as the cardiovascular system and breathing.
The results are in agreement with the previous study
The findings are consistent with a July study by Dr. Riaz Malik of Weill Cornell Medicine Qatar that found an association between corneal nerve fiber damage and a diagnosis of long-term COVID-19.
In the current study, 11 of 17 patients were treated with either steroids or intravenous immunoglobulin (IVIG), which is standard treatment for patients with minimal nerve fiber damage due to an immune response. Some improved, although none recovered.
While the results will only apply to long-term COVID patients with this type of nerve damage, it’s possible that immunotherapy could be beneficial, said Dr. Avindra Nath, an expert in neuroimmunology at the National Institute of Neurological Disorders and Stroke who was involved in the study. author.
“To me, this suggests that we need to do a proper prospective study for these types of patients” testing the drugs in a randomized trial, Nath said.