What Does “COVID-19 Brain Fog” Mean?

There are common symptoms associated with COVID-19, including fever, cough, shortness of breath, and fatigue. However, up to 25% of people who developed COVID-19 have noted neurological symptoms, or something described as “brain fog.” This term is not a medical diagnosis but rather a general phrase used to describe the feeling it causes. 

What does COVID-19 brain fog feel like? 

Brain fog is used to describe the feeling of being mentally slow, fuzzy, or spaced out. Symptoms associated with this feeling include memory problems, lack of mental clarity, mental exhaustion, and headaches. It is likely you may have occasionally experienced these feelings after a poor night's sleep or during periods of stress. 

Why does COVID-19 cause brain fog?

Researchers are still investigating the potential cause of brain fog, but there are some known factors that could play a role in bringing about this sluggish feeling. The new coronavirus, SARS-CoV-2, is thought to spread through close contact with someone who has the infection. This virus is neuro-invasive, meaning it can cross the blood-brain barrier and enter brain tissue. 

There have been a few case studies that show people with COVID-19 have developed inflammation in their brain, which slows or stops the neurons’ ability to communicate with each other, leading to brain fog. Indirect ways that COVID-19 might lead to brain fog include poor sleep quality, feelings of loneliness, and increased stress or anxiety. 

Is it normal to experience brain fog after recovering from COVID-19?

Like the cause of brain fog, research is still being done to understand how common it is to experience these symptoms after having COVID-19. A smaller study showed that between 7.5% and 31% of people experienced an altered mental state because of COVID-19. Another recent study found that cognitive symptoms could be more prevalent in people who experienced severe illness, with 69% of those in the study exhibiting symptoms. 

What is the link between COVID-19 and neurological disorders?

SARS-CoV-2 particles enter the body intranasally — through the nose — making their way up toward the olfactory bulb and other brain tissue. It is through the cells in the frontal lobe of the brain that SARS-CoV-2 enters healthy cells, causing damage to the blood-brain barrier. A headache, reduced sense of taste, and loss of smell occur before the onset of respiratory side effects. The most common neurological symptom is delirium, which reduces cognition and memory. 

Are there long-term effects?

A COVID-19 infection can cause an increased chance of stroke, especially for those over 70 years of age. The older population is known to frequently experience silent strokes, which are a risk factor for traditional stroke and dementia. Silent strokes affect the brain’s white matter, which allows brain cells to communicate with each other. 

Have you received your COVID-19 vaccine? Schedule yours at a St. Luke’s Health vaccine hub today. If your neurological symptoms after COVID-19 persist, make an appointment with a St. Luke’s Health neurologist.

Sources:

Healthline | What To Know About COVID-19 And Brain Fog

NCBI | Neurological Manifestations of COVID-19

Medical News Today | COVID-19 And The Brain: What Do We Know So Far?

NIH | Taking A Closer Look At COVID-19's Effects On The Brain

Harvard Health Publishing | The Hidden Long-Term Cognitive Effects of COVID-19 On The Brain