After examining PET images of patients with suspected long COVID, a study published in the European Journal of Nuclear Medicine and Molecular Imaging identified hypometabolic patterns in nearly half of all patients. 

Each of the 143 patients was experiencing neurological symptoms at the time of the 18F-FDG PET scan, such as fatigue, pain, memory or cognitive complaints and insomnia. On average, the scans were conducted 10.9 months after the onset of these symptoms.

While 53% of the scans were normal, 21% were classified as mildly to moderately affected according to previously reported COVID hypometabolic patterns and 26% were classified as severely affected. Experienced nuclear physicians classified each of the scans. 

“This pattern can be found at an individual level and helps to objectively assess metabolic abnormalities in patients with suspected neurological long COVID,” wrote lead author Antone Verger, of the Department of Nuclear Medicine at the Université de Lorraine in Nancy, France, and co-authors.

The study builds on previous work which had initially identified hypometabolic patterns in long COVID patients and had called for additional, multicenter studies with a larger number of patients. The results appear to validate the ability of nuclear physicians to identify brain abnormalities in long COVID patients, and indicate a possible role for the continued use of PET scans to assess neurological damage both on an individual and a group level.