Neuroscience: Long Covid Brain Fog Linked to Inflammation and Stress Markers

A new study comparing long COVID patients with fully recovered individuals has found that those with persistent cognitive symptoms, like brain fog, show higher brain inflammation and reduced capacity to handle stress. The study revealed lower levels of nerve growth factor and elevated inflammatory markers in the long COVID group.

Neuroscience News

Neuroscience Summary

Biomarker Imbalance: Long COVID patients had lower nerve growth factor and higher IL-10, indicating impaired neuroplasticity and inflammation
Language Deficits: Participants with long COVID performed worse on letter fluency tests, despite otherwise normal cognitive assessments.
Lower Quality of Life: Long COVID patients reported poorer physical, emotional, and psychological well-being than recovered individuals.

Extracts

The pilot study, published in PLOS One, included 17 confirmed COVID patients (10 with long COVID and seven who were fully recovered with no lingering symptoms) and found the following:

Serum levels of nerve growth factor, a biomarker of the brain’s ability to change and adapt by forming new connections, were significantly lower in the long COVID group. This group was also more likely to have higher serum levels of interleukin (IL)-10, a marker of inflammation.
While there was virtually no difference between groups related to neuropsychological test outcomes, long COVID participants did score significantly lower on letter fluency, meaning they had more difficulty with quickly and accurately accessing language centers in the brain and producing words beginning with various letters.
The long COVID group also had significantly lower ratings than healthy controls on quality of life, physical health, emotional functioning and psychological well-being responses.

Although this is a small study and more work needs to be done, from a clinical application standpoint, physicians potentially can identify individuals who are struggling sooner and provide wrap-around care that could be helpful to them.
Judith Arnetz, Ph.D., professor emerita at Michigan State University College of Human Medicine and corresponding author of the study.

Link to Neuroscience Article

Research Paper

MEA Comment

Some interesting preliminary findings from what is a very small study involving people with Long Covid.

But far too early to draw any firm conclusions about the possible role of these findings in relation to the cause of Long Covid symptoms.

However, we already know that low level neuroinflammation may be involved in ME/CFS – so this research is worth validating in a larger group of people – hopefully including a cohort with ME/CFS as well.

Dr Charles Shepherd,
Trustee and Hon. Medical Adviser to the ME Association,
Member of the 2018-2021 NICE guideline on ME/CFS committee,
Member of the 2002 Chief Medical Officer's Working Group on ME/CFS