Brain Fog and COVID-19

By Sana U. Khan, MD, PhD

Have you ever felt as if your brain was in a cloud? Or ever walked into a place and not sure why you were there? Although clinically defined as a feeling of mental confusion or lack of mental clarity, the feeling is commonly described as “brain fog.” It can start with seemingly ordinary incidents like forgetting where you parked or someone’s name, headaches, mood swings, anxiety, depression, or dizziness. Not thinking clearly has an impact on daily life, including driving and performing optimally at work. Those who work dangerous jobs that require quick thinking and decision making should be especially careful.

Adding to the confusion and frustration, doctors do not have a clinical diagnosis called “brain fog” because no specific diagnostic tests are available, and because the condition may have a significant overlay of a person’s opinions, feelings, and personal experiences.

However, even if brain fog is currently described as a subjective condition, a patient experiencing such difficulties finds the condition to be very real, and the signs of brain fog should not be ignored. In addition, and very importantly, brain fog should not be confused with common medical conditions such as dementia, mental retardation, anxiety, or chronic depression. In children, brain fog may lead to lack of concentration at school and work, low self-esteem, accidents, and troubled relationships. It can cause intense frustration and the inability to function well in society.

The causes of brain fog have mostly been defined through conditions associated with symptoms such as a foggy head from a lack of sleep, low blood-sugar, allergies, dehydration, or electrolyte imbalance from heavy exercising. Other causes defined include mercury poisoning, hormone imbalance, fibromyalgia, thyroid conditions, or Lyme disease. Women during menopause also often describe having “brain fog.”

One of the most commonly reported factors in brain fog is stress. The stress-brain loop if well understood. Chronic stress leads to inadequate sleep, poor nutrition and emotional distress. These conditions lead to increased glucocorticoids and decreased regulation of cortisol which, in turn, leads to cellular changes in an area of the brain called the hippocampus. The hippocampus is involved in processing attention, perception, short-term memory, learning and word finding. These symptoms are commonly reported by patients complaining of brain fog.

Interestingly, the recent COVID-19 pandemic is bringing heightened attention to brain fog as numerous patients reported experiencing this condition. Many COVID-19 patients reported troubling cognitive symptoms that can include memory loss, confusion, difficulty focusing, dizziness and grasping for everyday words. Increasingly, COVID survivors say brain fog is impairing their ability to work and function normally. Consequently, the impact on the affected work force is going to be significant.

Scientists are not sure what causes brain fog, which varies widely and affects even people who became only mildly physically ill from COVID-19 and had no previous medical conditions. Leading theories are that it arises when the body’s immune response to the virus does not shut down, or else from inflammation in blood vessels leading to the brain.

Confusion, delirium, and other types of altered mental function, called encephalopathy, have occurred during hospitalization for COVID-19 respiratory problems. Studies found such patients needed longer hospitalizations, have higher mortality rates, and often cannot manage daily activities right after hospitalization.

But research on long-lasting brain fog is just beginning. A French report in August 2020 on 120 patients who had been hospitalized for COVID-19 found that 34 percent had memory loss and 27 percent had concentration problems months later.

In a soon-to-be-published survey of 3,930 members of Survivor Corps, a group of people who connected to discuss life after COVID, over half reported difficulty concentrating or focusing, said Natalie Lambert, an associate research professor at Indiana University School of Medicine, who helped lead the study. Brain fog was the fourth most common symptom out of the 101 long-term and short-term physical, neurological, and psychological conditions survivors reported. Memory problems, dizziness, or confusion was reported by a third or more respondents.

Post COVID-19 patients often describe their condition as debilitating, almost catatonic or feeling as if under anesthesia, but the cause of their brain fog continues to be a medical  mystery partly because symptoms are so varied. Since inflammatory molecules, released in effective immune responses, can also be sort of toxins, particularly to the brain, one theory is that people still have persistent immune activation after the initial COVID-19 infection subsides, and that inflammation in blood vessels, or cells lining the vessels, may be involved. Some doctors believe tiny strokes may also be leading to the symptoms, while others suggest possible causes such as autoimmune reactions when antibodies mistakenly attack nerve cells causing symptoms like tingling or numbness. Some people with brain fog still experience lung or heart issues, which can also exacerbate neurological symptoms.

With COVID-19, doctors do not know whether symptoms will improve or evaporate with time. Meanwhile, patients are forced to devise workarounds or makeshift recovery exercises. Experts advise people with brain fog to see doctors to rule out other medical conditions and treat remaining physical symptoms. So far, MRI scans have not indicated damaged brain areas, but brain fog is very real, and continued research in this area is very important so that the symptoms are taken seriously.

Some things one may do to reduce (or perhaps fix) brain fog:

1. Eat foods right for your needs.
2. Learn to control your stress.
3. Practice memory-strengthening exercises.
4. Learn to cope.
5. Get quality sleep.
6. Take brain boosters (e.g., Omega-3, magnesium, etc.…).
7. Lay off cigarettes and alcohol.
8. Check for allergies.
9. Engage in physical exercise.
10. Practice active relaxation.

You may find other helpful practices, but most importantly, stay positive as negative energy commonly brings negative results.

Dr. Sana Khan is an accomplished radiologist, researcher, teacher, and entrepreneur. He was the first radiologist in the United States with the Stand-Up Weight-Bearing MRI and has contributed significantly to the advancement of this technology. He is a nationally- renowned scientist conducting ongoing research with the Departments of Orthopedic Surgery at UCLA, USC, UCSD, and the US Department of Defense. Having developed state-of-the-art MRI techniques, Dr. Khan brings extensive expertise in the medical-legal aspect of imaging musculoskeletal and traumatic brain injuries. www.expertmri.com