BRAIN FOG AFTER COVID-19 INFECTION: FACT OR FICTION?

It’s been almost 5 years since the first case of COVID-19 was identified. Since then, scientists have learned a great deal about the virus, including the fact that it is neuro-invasive. This means the virus has the ability to attack the nervous system, especially the central nervous system.

In fact, SARS-CoV-2 has been cultured from brain tissue and its viral proteins have been found in cerebrospinal fluid (CSF). Once in the brain, the virus can attack the neurons and synapses, resulting in abnormal release and uptake of neurotransmitters. Some common neurotransmitters are serotonin, norepinephrine, acetylcholine, and dopamine. These are responsible for our mood, memory, and comprehension (amongst others) which can be adversely affected during and after SARS-CoV-2 infection.

Furthermore, COVID-19 also has the ability to attack the lungs, and specifically the alveolar sacks, where oxygen and carbon dioxide are exchanged. The virus can therefore cause a decrease in the oxygenation of blood. Whenever there is a decrease in the oxygenation of blood, we are at risk of cerebral hypoxia (brain injury from a lack of oxygen). Long term effects of cerebral hypoxia include memory loss, difficulties concentrating, and word finding problems, amongst other neurocognitive issues.

Lastly, because COVID-19 can cause hypercoagulation (thickening) of the blood, there is an increased risk of stroke. Results of strokes vary depending on the severity of the stroke and location of the stroke in the brain. Nevertheless, individuals will experience changes/decline in their neurocognitive functioning, such as memory impairment, speech impairment, or visual/perceptual deficits.

Unfortunately, brain fog is all too common a lasting symptom of COVID-19. However, the degree is largely based on the severity of the infection and the individuals’ pre-existing conditions. In general, the healthier the individual was pre-infection, the less likely he/she will have residual effects from COVID-19. Overall, we should all strive to take better care of our health - body and brain!

BRAIN DAMAGE & NEUROPLASTICITY

We often think that an injury to the brain is irreversible, but science tells us that our brains have tremendous regenerative capabilities. An example being the ability to form new neurons and glial cells, in a process referred to as neurogenesis. Our brains are also able to form new connections and alter older ones through multiple processes, including synapse formation and elimination, dendritic remodeling, axonal sprouting, and pruning. These capabilities are collectively called neuroplasticity. 

This informs us that in mild to moderate brain injury cases, and with the right rehabilitation, we can often repair our brains and in effect, reverse the damage. For example, if someone has suffered a mild frontal lobe injury from a car accident and developed issues with focus and concentration, with the appropriate rehabilitation, he/she has significant potential to improve. It is important to note that the healthier the baseline functioning of the brain, the better the neuroplasticity. 

Neuroplasticity weakens as we age. This weakening is further exacerbated by neurological insults to our brains, such as the use of substances (i.e. Alcohol, tobacco), comorbid conditions (i.e. Depression), and exposure to neurotoxins and free radicals.

Much like other muscles in our body, the brain needs stimulation and repetition. If you don’t use it, you’ll lose it! As a golden rule of thumb, for rehabilitation of the brain, timely intervention is of the essence. Generally, the best recovery will occur in the first 6 to 12 months from the brain injury. It is therefore crucial to prioritize brain rehabilitation immediately after any brain damage.