Patients Numb or Weak Post-COVID? Order an MRI or Ultrasound

Prone positioning – a measure used to help COVID-19-positive patients breathe – can cause a stretch injury, leading to lingering nerve damage. An MRI or ultrasound can help providers diagnose what might actually be behind the injury and its impacts, as well as play a role in determining the best course of treatment.

In a study published Dec. 1 in Radiology, investigators from Northwestern Medicine show that using advanced imaging can answer these questions for patients who have recovered from the virus and are left suffering with chronic, debilitating pain or weakness in their hands, feet, arms, and legs. This is the first paper to delve into how imaging can help pinpoint and treat nerve damage in these patients.

“Let’s say you have numbness in your fingers. That might actually be due to problems in your neck, elbow or waist, and the best way to figure it out is with an MRI or ultrasound,” said Swati Deshmukh, M.D., assistant professor of radiology at Northwestern University Feinberg School of Medicine and Northwestern Medicine radiologist. “We offer advanced imaging that shows even really, really small nerves, which helps us localize where the problem is, assess the severity, and suggest what might be causing it.”

Previous research from Northwestern already showed that prone positioning in this patient group can cause nerve damage. But, this paper went further, detailing how advanced imaging can help those patients, as well as two other patient cohorts that have COVID-19-related nerve damage. Based on their findings, imaging can also be used with patients who have nerve damage:

• Secondary to an inflammatory immune response that attacked the nerves, and
• From a hematoma

Specifically, Deshmukh said, providers can use ultra-high-resolution ultrasound and MR neurography – and MRI of the peripheral nerves in the arms and legs – to pinpoint the location of the patient’s problem, visualize the severity of the damage, determine how many nerves are affected, and figure out whether any muscles have been affected.

In some cases, she said, ultrasound might be the better option. Not only is the ultra-high-resolution technology new, portable, and less expensive, but, in some cases, it also outperforms MRI in detecting nerve damage. In addition, some patients are not able to tolerate an MRI, making ultrasound the preferable modality.

Depending upon the type of nerve damage identified, the results can be used to map out the patient’s treatment. For nerve damage from prone positioning, she said, patients can be referred to a doctor who specializes in rehabilitation or peripheral nerve surgery. Nerve damage from an inflammation response warrants an appointment with a neurologist, and injury from a hematoma points to the immediate need for a blood thinner and a potential meeting with a surgeon.

Ultimately, she said, providers can employ advanced imaging as a treatment guide for COVID-19 patients and survivors who have neuromuscular complications or lingering problems.

“I have to wonder if there are physicians out there who are seeing these otherwise young, healthy patients, and they don’t know exactly what’s wrong, and they’re thinking, ‘What am I supposed to do for patients with post-COVID pain and weakness,” Deshmukh said. “I want physicians and patients to be aware of the diagnostic options available due to recent innovations in technology and inquire if advanced imaging might be right for them.”