Study Finds Potential Cause of COVID ‘Brain Fog’

F.J. Thomas

Sarasota, FL ( – While the primary focus on COVID-19 has been the effect that it has on the lungs, the disease also effects the nervous system. The side effects of memory problems and brain fog are commonly reported post COVID. Some studies have shown that cognitive issues plague as many as 67 percent of patients post COVID.

A small study published in the Annals of Clinical and Translational Neurology may give some insight to how the virus causes brain fog months after being sick, and the risk factors associated with cognitive issues post COVID. Researchers at the University of California, San Francisco and Weill Cornell Medicine, New York studied the spinal fluid of people who had tested positive for COVID and found abnormalities that could be contributing to brain fog and other cognitive difficulties.

The research team studied 32 patients that were post COVID and did not require hospitalization during their illness. The average age of the COVID group was 48 compared to 39 for the control group. Twenty-two of the patients reported cognitive symptoms.

According to the researchers, other viral conditions such as HIV, Epstein-Barr and hepatitis C can also cause cognitive issues. The patients underwent cognitive tests, scored using criteria for HIV-associated neurocognitive disorder, or HAND. Fifty-nine percent had objective cognitive impairment according to the results of the testing. The patients with brain fog had trouble with remembering recent events, staying focused, information retention and use, as well as slower processing time. Onset of cognitive decline greater than 30 days after first COVID symptom was reported by 43 percent of those that reported brain fog. Twenty-nine percent reported symptoms after 2 months.

Lumbar punctures were done on 17 of the patients, 4 of which reported no cognitive issues. The average time of the lumbar punctures was 10 months after the first symptom of COVID. The spinal fluid of those without cognitive issues was normal, however the spinal fluid of 10 of the 13 remaining patients was abnormal.

Although the time period of the lumbar punctures would suggest the virus was no longer present, the researchers found elevated levels of protein in the abnormal specimens, suggesting unexpected antibodies and high levels of inflammation. High levels of protein were found in blood and spinal fluid, suggesting a systemic inflammatory response, and some were only found in the spinal fluid suggesting inflammation of the brain. Overall, the researchers suspect that the virus potentially activated the immune system, creating in some cases an autoimmune storm where the body basically attacks itself.

The researchers noted specific risk factors associated with the cognitive difficulties. Those with cognitive issues had an average of 2.5 cognitive risk factors, with the main risks factors including diabetes hypertension, and ADHD. Other risk factors included learning disabilities, alcoholism or substance abuse, anxiety and depression.