People with post-Covid fatigue were found to be active in key areas of the nervous system, increasing the risk of fatigue — one of the most common long-term Covid symptoms, researchers said.
A team at the University of Newcastle in the United Kingdom conducted a battery of behavioral and neurophysiological tests on people who suffered from post-Covid fatigue and compared it to people without fatigue.
The researchers found that people with post-Covid-related fatigue showed inactivity in three specific areas of the nervous system.
They found slower responses in certain brain areas due to lower activity in certain cortical circuits. Dysregulation of the autonomic nervous system — the body that controls unconscious body processes such as blood pressure and breathing rate — is found to be impaired. This can have a wide impact on various body processes.
They also found muscle dysfunction — muscle fibers weakened more easily after exercise than people without post-Covid fatigue.
“These abnormalities in the results of the experimental tests show that long-term covid fatigue is a measurable disease and these tests will help us understand how changes in the nervous system contribute to fatigue,” said Dr. Dimitris Soteropoulos, Senior Lecturer in Motor Neuroscience Systems at the University.
The study was published in Brain Communications.
A group of 37 volunteers with post-Covid fatigue underwent well-established non-invasive behavioral and neurophysiological experiments. Their results were compared with those of 52 controls, matched for age and sex, who underwent the same tests. The tests that provided 33 data sets included baseline reaction time testing, electrocardiogram, and transcranial magnetic stimulation.
Following these findings, the team will now begin investigating whether the autonomic nervous system can be modulated to improve post-Covid fatigue symptoms.
“We are investigating a non-invasive method that involves cutting the earpiece on the tragus of the ear and sending small electrical currents to the vagus nerve using a TENS machine – a common practice for many to relieve pain during childbirth,” he said. Natalie Maffitt, Research Assistant at Varsity.
The study will examine the effects of the treatment by measuring markers of inflammation in the blood associated with fatigue in other conditions and, importantly, improve symptoms of fatigue.