according to a new study published in the journal Neurology: Neuroimmunology & Neuroinflammation (doi: 10.1212/NXI.0000000000001146).
The nerve damage, which has been seen even among mild coronavirus cases, appears to be caused by immunity problems triggered by infection.
“This is one of the early papers looking into causes of long COVID, which will steadily increase in importance as acute COVID wanes,” Anne Louise Oaklander, MD, the lead study author and a neurologist at Massachusetts General Hospital, Boston, said in a statement.
“Our findings suggest that some long COVID patients had damage to their peripheral nerve fibers and that damage to the small-fiber type of nerve cell may be prominent,” she said.
The research team analyzed data from 17 COVID-19 survivors with lingering symptoms who had no history or risks of neuropathy, or nerve damage or disease. The patients were from 10 states and territories, and all but one had mild infections.
They found that 10 patients – or 59% – had at least one test that confirmed neuropathy. Two patients had rare neuropathies that affected muscle nerves, and 10 were diagnosed with small-fiber neuropathy, which is a cause of chronic pain. Common symptoms included fatigue, weakness, changes in their senses, and pain in their hands and feet.
For treatment, 11 patients were given immunotherapies such as corticosteroids or intravenous immunoglobulins, and the five patients who received repeated IgG treatments appeared to benefit. Over time, 52% of patients improved, though none had all of their symptoms go away.
“Research from our team and others is clarifying what the different types of post-COVID neuropathy are and how best to diagnose and treat them,” she said. “Most long COVID neuropathies described so far appear to reflect immune responses to the virus that went off course.”
Dr. Oaklander noted that researchers haven’t been able to do clinical trials to evaluate specific post-COVID neuropathy treatments. But some existing treatments may help.
“Some patients seem to improve from standard treatments for other immune-related neuropathies,” she said.
A version of this article first appeared on WebMD.com.