What Is COVID-19 Doing to the Brain?

The more people who are infected with the novel (new) coronavirus that causes COVID-19, the more we’re learning about its effects in the body.

Mounting evidence is showing that the virus, called SARS-CoV-2, is neurotropic, or capable of infecting nerve cells.

And while no one has suggested that such infections are more likely to occur in people who already have disease affecting their brains — such as multiple sclerosis (MS) — it’s hard for those of us already living with neurological conditions not to be anxious about the possible consequences such a viral invasion could have.

As early as February 2020, the first reports out of Wuhan, China, where the first cases of what came to be known as COVID-19 were reported in December 2019, stated that “Compared with non-severe patients with COVID-19, severe patients commonly had neurologic symptoms manifested as acute cerebrovascular diseases, consciousness impairment, and skeletal muscle symptoms.”

Another study by Asian researchers, published in February, raises the question (but reached no conclusion) as to whether “potential [neuro]invasion of SARS-CoV-2 is partially responsible for the acute respiratory failure of patients with COVID-19.”

By the end of March, physicians from the Henry Ford Health System in Detroit reported in the journal Radiology the first case of COVID-19-associated acute necrotizing hemorrhagic encephalopathy, a rare central nervous system complication secondary to influenza or other viral infections that is characterized by altered mental status and seizures. It often leads to profound disability or death.

There are further reported cases of neurologic involvement by SARS-CoV-2, some of which appear to show receptors for the virus not only in the respiratory and digestive tracts but also in the blood-brain barrier and central nervous system nerve endings.

In a letter published on April 15 in the New England Journal of Medicine, doctors in Strasbourg, France, described the neurological features they observed in 58 patients admitted to the hospital because of acute respiratory distress syndrome (ARDS) due to COVID-19. They reported seeing encephalopathy (a general term for damage to the brain), prominent agitation and confusion, and corticospinal tract signs (a broad range of signs of central nervous system damage), as well as two ischemic strokes. They said it was unclear which if any of these were directly caused by the viral infection.

While the level of central nervous system (CNS) involvement in COVID-19 is not fully understood, it is not lost on MS neurologists or patients that some of the disease-modifying therapies (DMT) used to treat multiple sclerosis “turn off” immune surveillance of the CNS.

In other words, if a person with MS were to acquire COVID-19, and their CNS were infiltrated by the virus, their prognosis would likely include major complications from the infection. We’ve seen such things before in the way of PML and other opportunistic infections allowed by some MS medications.

All the more reason for people with MS, particularly those on disease-modifying therapies associated with PML, to be extra vigilant about social distancing and self-isolation during this pandemic.