The largest multi-institutional international study to date on brain complications associated with COVID-19 has found that approximately one in 100 patients hospitalised following SARS-CoV-2 infection will likely develop complications of the central nervous system. These can include stroke, haemorrhage and other potentially fatal complications.
The study was recently presented at the annual meeting of the Radiological Society of North America (RSNA; 28 November–2 December 2021, Chicago, USA and virtual).
“Much has been written about the overall pulmonary problems related to COVID-19, but we do not often talk about the other organs that can be affected,” said the study’s lead author Scott H Faro, professor of radiology and neurology, and director of the Division of Neuroradiology/Head & Neck Imaging, at Thomas Jefferson University in Philadelphia, USA. “Our study shows that central nervous system complications represent a significant cause of morbidity and mortality in this devastating pandemic.”
Faro initiated the study after discovering that existing literature on central nervous system complications in hospitalised patients infected with COVID-19 was based on a relatively small number of cases.
To derive a more complete picture, he and his colleagues analysed nearly 40,000 cases of hospitalised COVID-19-positive patients from seven US and four western European university hospitals. The patients had been admitted between September 2019 and June 2020. Their average age was 66 years, and there were twice as many men as women.
The most common cause of admission was confusion and altered mental status, followed by fever. Many of the patients had comorbidities like hypertension, cardiac disease and diabetes.
There were 442 acute neuroimaging findings that were most likely associated with the viral infection. The overall incidence of central nervous system complications in this large patient group was 1.2%.
“Of all the inpatients who had imaging, such as MRI [magnetic resonance imaging] or a CT [computed tomography] scan of the brain, the exam was positive approximately 10% of the time,” Faro added. “The incidence of 1.2% means that a little more than one in 100 patients admitted to the hospital with COVID-19 are going to have a brain problem of some sort.”
The most common complication was ischaemic stroke, with an incidence of 6.2%, followed by intracranial haemorrhage (3.72%) and encephalitis (0.47%)—an inflammation of the brain.
The researchers also discovered a small percentage of unusual findings, such as acute disseminating encephalomyelitis—an inflammation of the brain and spinal cord—and posterior reversible encephalopathy syndrome, which is a syndrome that mimics many of the symptoms of a stroke.
“It is important to know an accurate incidence of all the major central nervous system complications,” Faro concluded. “There should probably be a low threshold to order brain imaging for patients with COVID-19.”