COVID-19: Study points to long-term neurological effects

09 January, 2021
A recently available paper examining existing evidence argues that SARS-CoV-2 an infection might increase the threat of long-term neurological complications, including cognitive decline and dementia.

Nearly 1 year following the novel coronavirus, SARS-CoV-2, was identified, global cases have surpassed 88 million. Although several vaccines have been approved, the rollout will need time.

In the meantime, experts continue studying COVID-19 in an attempt to slow the spread and lessen severe symptoms.

Other scientists are trying to piece together an image of what life may look like over time for anyone who has had COVID-19.

A recent point of view article, which appears in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association, reviews study into past viral ailments, including the flu pandemic from a hundred years earlier. The authors consider the study indicates COVID-19 might lead to a lasting influence on the brain.

Neurotropic viruses
Scientists consider the SARS-CoV-2 virus a “neurotropic” virus, because it can enter nerve cells. Neurotropic infections include the mumps, rabies, and Epstein-Barr viruses. Although some neurotropic viruses cause milder symptoms, others can cause swelling in the brain, paralysis, and death.

Some flu-like viruses are neurotropic and identical in structure to the novel coronavirus. As such, researchers viewed these viruses to attempt to gain insight into which kind of long-term effects to expect in people who've recovered from COVID-19.

“Since the flu pandemic of 1917 and 1918, a lot of the flu-like diseases have been connected with brain disorders,” says lead author Dr. Gabriel A. de Erausquin.

Dr. de Erausquin, who is a neurology professor at the University of Texas Health and wellbeing Science Centre at San Antonio, clarifies: “Those respiratory viruses included H1N1 and SARS-CoV. The SARS-CoV-2 virus, which causes COVID-19, is certainly also recognized to impact the mind and nervous system.”

In line with the scientists, an increased threat of Alzheimer’s disease, Parkinson’s disease, and mental health problems could potentially be connected to these flu-like ailments.

Need for neurological symptoms
Some persons with COVID-19 usually do not experience any symptoms, while others have symptoms ranging from mild to severe.

A number of the hallmark symptoms include:

  • dry cough
  • fever
  • difficulty breathing
Additionally, an estimated 15-25% of folks with the viral illness may have got neurological symptoms, including:

  • lack of sense of tastes and smell
  • altered mental state
  • headache
While losing the good sense of smell might not exactly seem serious initially, it is still important, since it is tied right to brain function.

To get into cells, SARS-CoV-2 binds to ACE2 receptors on cell membranes. The olfactory bulb, which may be the area of the brain acquiring sensations of smell, harbors a high concentration of the receptors. The olfactory bulb also offers solid connections to the hippocampus - the area responsible for memory.

According to Dr. de Erausquin, “The trail of the virus, when it invades the mind, leads almost straight to the hippocampus.”

“That is believed to be one of the sources of the cognitive impairment seen in COVID-19 sufferers. We suspect it may also participate the reason why you will see an accelerated cognitive decline over time in susceptible persons,” he adds.

Among extreme neurological issues during SARS-CoV-2 infection, affected individuals may develop liquid on the mind, inflammation in the mind, and seizures.