Healthcare workers and patients who have acquired SARS-CoV-2, particularly if they were hospitalized, could be at risk of neurological deficits in the short term as well as long-term cognitive problems, says Majid Fotuhi, MD, PhD, the lead author of a new paper on the effects of COVID-19 on the brain.1

“For healthcare workers, there are two issues,” says Fotuhi, medical director of NeuroGrow Brain Fitness Center in McLean, VA, and an affiliate staff member at Johns Hopkins Medicine. “One is the impact of SARS-CoV-2 virus itself [on the] brain. The other is the stress of the COVID-19 pandemic, seeing patients die before their eyes. That causes post-traumatic stress disorder [PTSD]. I think we need to monitor frontline healthcare workers even more closely [than patients] because the stress response in our body can actually harm the brain significantly.”

Anosmia, “stroke, paralysis, cranial nerve deficits, encephalopathy, delirium, meningitis, and seizures are some of the neurological complications in patients with COVID-19,” Fotuhi and co-authors noted. “There remains a challenge to determine the extent to which neurological abnormalities in COVID-19 are caused by SARS-CoV-2 itself, the exaggerated cytokine response it triggers, and/or the resulting hypercoagulopathy and formation of blood clots in blood vessels throughout the body and the brain.”

The article authors reviewed neurological problems reported in COVID-19 patients and proposed a basic “NeuroCovid” classification scheme.

“Keeping accurate registries of COVID-19 patients with neurological deficits may enable us to establish plausible connections with aging-associated and neurodegenerative disorders such as Parkinson’s disease in the future,” the authors concluded. “Standardized evaluations such as quantitative EEG, fluid biomarkers, cognitive evaluations, and multimodal neuroimaging can also lend insight to possible long-term neurological sequalae in COVID-19 such as depression, memory loss, mild cognitive impairment, or Alzheimer’s disease.”

The authors identified three distinct NeuroCovid neurological categories or stages:

• Stage I: The virus damage is limited to epithelial cells in the nose and mouth. “Ninety-five percent recover without any problem,” Fotuhi says. “These are the patients who are least likely to have long-term neurological problems.”

• Stage II: Patients may experience blood clots in their brain partially caused by an inflammatory immune response called the “cytokine storm.” This can result in mini-strokes that may cause cumulative neural damage.

“We can take care of large strokes the same way we do in patients that do not have COVID-19,” Fotuhi says. “But when they have small strokes, the patient may have no symptoms, an MRI is not done, and no one knows what this patient has suffered. These patients, long term, are likely to have depression, memory loss, and other neurological [problems].”

• Stage III: This damages the blood-brain barrier, which protects blood vessels of the brain, causing seizures or encephalopathy.

“The cytokine storm is so huge that it ruptures and damages the blood-brain barrier, such that the virus particles get inside the brain along with the inflammatory markers,” Fotuhi says. “When that happens, there is significant damage to the brain cells. These are the patients who I think will have the highest degree of neurological issues in the future.”

There are blood tests to measure the intensity of the inflammatory immune response, which may be responsible for the relatively rare severe infections in younger people. “It is the body’s own immune system that harms the patient,” he says.

In healthcare workers, the neurological effects of COVID-19 could be compounded by the stress of fighting the pandemic.

“The more stressed you are, the more the part of your brain for memory — the hippocampus — shrinks,” Fotuhi says. “Frontline healthcare workers dealing with patients in dire situations experience an extreme amount of stress. The cortisol that is produced in response to stress indirectly harms the hippocampus. We need to monitor our healthcare workers dealing with COVID-19 patients closely. They may have secondary harm due to PTSD, even if they don’t have the virus themselves.”

PTSD can harm areas of the brain affecting regulation of emotion, memory, and executive functions, he adds.

Overall, the basic measures to boost brain performance, regardless of patient history, include vigorous exercise, stress reduction, and eight hours of sleep nightly, he recommends.

REFERENCE

  1. Fotuhi M, Mian A, Meysami S, et al. Neurobiology of COVID-19. J Alzheimers Dis 2020;76:3-19.