A small study of patients suffering from persistent symptoms long after a bout of COVID-19 found that nearly 60% had nerve damage possibly caused by a defective immune response, a finding that could point to new treatments, U.S. researchers reported on Tuesday.

The study involved in depth exams of 17 people with so-called long COVID-19, a condition that arises within three months of a COVID-19 infection and lasts at least two months.

"I think what's going on here is that the nerves that control things like our breathing, blood vessels and our digestion in some cases are damaged in these long COVID patients," said Dr. Anne Louise Oaklander, a neurologist at Massachusetts General Hospital and a lead author on the study published in Neurology: Neuroimmunology & Neuroinflammation.