Comorbidities May Contribute to Neurologic Effects in COVID-19 Patients

Ingrid Hein

December 07, 2020

Editor's note: Find the latest COVID-19 news and guidance in Medscape's Coronavirus Resource Center.

Neurologic complications from COVID-19 are common in patients with diabetes and hypertension, according to new research presented at the virtual Radiological Society of North America (RSNA) 2020 Annual Meeting.

Colbey Freeman

"Patients with these conditions may be at higher risk for neurologic complications and should be monitored closely," study lead Colbey Freeman, MD, Penn Medicine, Philadelphia, told Medscape Medical News.

In an effort to understand why a disease of the chest may be related to neurologic complications, researchers investigated comorbidities and commonalities in COVID-19 patients who had brain bleed and stroke. "We really don't have a good mechanism for why this is happening," Freeman said.

The research team noted that blood markers of inflammation were high in the patients who had CT and MRI ordered, leading them to believe that cytokine storm from COVID-19 pneumonia may have released inflammation to the brain. Additionally, low oxygen levels in patients with pneumonia or lung inflammation may lead to hypoxic, ischemic injury. "With low oxygenation in the brain, with a saturation of 60% for an extended time, it's a perfectly reasonable assumption this may contribute," Freeman surmised.

"But what is causing these complications is still under debate," he added.

Investigators examined the health records of 1357 patients with COVID-19 presenting to the University of Pennsylvania Health System from January 1 to April 27. They identified 81 patients who underwent brain imaging. Of those, 73 had a CT scan, one had an MRI only, and seven had both CT and MRI. Eighteen of the 81 patients had "critical" findings, defined by acute/subacute intracranial hemorrhage, acute/subacute infarct, vascular occlusion, hypoxic-ischemic encephalopathy, or herniation.

Of the 81 patients who had an MRI or CT, 52 (64.2%) had a history of hypertension and 32 (39.5%) had type 2 diabetes mellitus.

In the group of 18 patients with critical test results, 13 (72.2%) had hypertension and nine (50.0%) had type 2 diabetes.

"Patients with diabetes and hypertension really stuck out disproportionately," Freeman reported.

He said neurologic complications of COVID-19 need to be studied further, as the inflammation could lead to complications later.

From a clinician perspective, he said it's concerning that some people may have inflammation with delayed consequences, that "4 weeks later, they could have a stroke." It's possible that COVID-19 may have some kind of brain pathology, he added.

"We need to better understand, when you recover from COVID-19, are you out of the woods? Or are you still susceptible?"

Age and Race Under Scrutiny

Researchers reported that neurologic complications were not always attributable to patient age. Although the mean age of the 18 patients with critical findings was 60.5 years, seven of them were younger than 55 years old and three were in their 40s.

Freeman highlighted the fact that 46 of the 81 (57%) patients who underwent brain imaging were Black. This population also made up 66.7% (12 of 18) of the patients with critical brain CT and MRI findings. "This is a question we had; a large portion of our patients were from West Philadelphia, where there is a large African-American population, and there were relatively more African-American patients with critical findings than were scanned," Freeman said. "Is being African-American an additional risk factor, which could have many possible explanations, or a confounder, as they also had hypertension and diabetes?"

Of the 81 patients who had neurologic imaging, 18 (22%) died. Three of the 18 with critical findings died from intraparenchymal hemorrhage.

Freeman's research group is now studying a group of thousands more COVID-19 patients from the University of Pennsylvania Health System and other health systems to identify neurologic complications. "That study will be powered by a higher number of people," he said.

Evidence Mounting for Comorbid Conditions

"We've known for quite some time that people who have various comorbidities are at higher risk of further complications if they are SARS-CoV-2-positive and develop COVID-19," said Jason Dyck, PhD, University of Alberta, Edmonton, Canada.

"This study adds another piece of evidence confirming this," Dyck commented. "Neurologic complications associated with COVID-19 can be added to the growing list of medical issues that we need to be concerned about and to monitor closely."

Freeman and Dyck have disclosed no relevant financial relationships.

Radiological Society of North America (RSNA) 2020 Annual Meeting.

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