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MRI scans may help physicisans treat long-haul COVID-19. FS Productions/Getty Images
  • Two new studies, conducted by radiologists, show how advanced imaging has captured the rate of nerve damage in people who have COVID-19.
  • Understanding what’s behind the nerve pain can help inform what treatment method doctors prescribe to people with nerve damage.
  • Some people have hematomas that might cause nerve damage. Others have injuries after being hospitalized for a long period.

All data and statistics are based on publicly available data at the time of publication. Some information may be out of date. Visit our coronavirus hub and follow our live updates page for the most recent information on the COVID-19 pandemic.

It’s become increasingly clear that COVID-19 can have a tremendous impact on our brain and nerves, not only in people who have an active coronavirus infection but in those who have recovered as well.

Two new studies, conducted by radiologists, show how advanced imaging has captured the rate of nerve damage in people with COVID-19.

The first study, published Tuesday in Radiology, was conducted by researchers at Northwestern University. They found that MRIs and ultrasounds can help doctors identify the type and cause of people’s nerve pain.

The radiologists behind the second analysis, published in the American Journal of Roentgenology (AJR) in late November, found that the exaggerated response some people’s immune systems produce could affect blood flow and trigger abnormalities in the central nervous system.

The new research highlights the need to properly diagnose nerve damage caused by COVID-19 so people can receive targeted medications and treatments.

There’s been a wide range of nerve pain reported by people with COVID-19.

Most commonly, they experience muscle injury or muscle aches (myalgia).

Dr. Swati Deshmukh, a Northwestern Medicine radiologist and lead author of Northwestern’s study, said this is because the nerves and muscles are closely interlinked.

“The thing about nerves is they innervate our muscles, so when you talk about nerves you’re really talking about muscles at the same time. They go together,” Deshmukh said.

Some people experience muscle weakness, fatigue, or trouble walking. Others have pain throughout their body, numbness, tingling, and foot drop, or difficulty lifting the front of the foot.

With nerve pain, many of the physical activities people previously enjoyed could became painful, said Deshmukh.

“It really depends what nerve is affected,” she said.

According to Deshmukh, there are multiple factors causing nerve damage in people with COVID-19.

For some, an overwhelming inflammatory response could be causing the nerve damage. In responding to the coronavirus, some people’s bodies produce massive immune responses that inflame and damage the body’s cells.

According to Dr. Amit Mahajan, a neuroradiologist at Yale Medicine and senior corresponding author of the AJR study, the body’s immune system gets revved up and produces inflammatory cytokines.

These cytokines weaken the capillaries (the network of blood vessels) and cause them to leak fluid, damaging nearby cells.

“Because of that, it damages the brain and the nerves itself,” Mahajan said.

COVID-19 also disrupts blood flow. It can cause blood to clot outside the blood vessels and form a hematoma.

Mahajan said a lot of the damage seen on MRIs appears to be caused from hematomas.

Lastly, how people with severe COVID-19 are positioned on their hospital bed may bring on nerve pain. Throughout the pandemic, doctors have been placing very sick patients on their stomachs to facilitate breathing.

In this belly-down position, the arms are stretched overhead.

“That kind of stretches the nerve in the armpit area, and that is basically causing some degree of damage,” Mahajan said.

It’s still unclear whether the coronavirus may directly infect our nerves.

We’ve seen this occur with other viruses — such as shingles, polio, and herpes — and there’s some evidence that the kind of receptors the coronavirus latches onto (ACE2 receptors) are common in the nervous system.

But Mahajan said there’s little evidence suggesting the coronavirus directly infects our nerves. Still, it can’t entirely be ruled out just yet.

“The most plausible explanation is that [the nerve damage] might be because of the inflammation and the positioning to some extent,” Mahajan said.

One of the key learnings from Northwestern’s study was how helpful advanced imaging — specifically, MRIs and ultrasounds — is in diagnosing nerve damage.

The imaging technology, which has advanced significantly in recent years, can identify where the nerve damage is, how many nerves might be affected, and whether the damage has reached the muscles. It can also help pinpoint the causes behind the nerve damage.

Deshmukh said doctors can use this information to inform treatment for each patient with nerve damage.

For example, if an overactive inflammatory response is causing the nerve pain, the patient might want to see a neurologist who could treat them with intravenous (IV) medications.

If the pain is from body positioning in the hospital, a rehabilitation specialist could conduct nerve stimulation.

Lastly, if there’s a hematoma, or if the nerve damage is severe, the patient could see a surgeon.

“When you think about treatment, the first thing you want to ask is, what is causing the nerve damage? The imaging will really show what the cause is, and based on the cause, the patient can be sent to the appropriate specialist and receive the appropriate treatment,” Deshmukh said.

New research shows just how common nerve damage is in people with COVID-19, and how advanced medical imaging can help doctors pinpoint the type and cause of nerve pain.

Understanding what’s behind the nerve pain can help inform which treatment doctors prescribe to patients with nerve damage.