Long-COVID patients show no brain dysfunction on PET scans, suggesting fatigue as main culprit
Long-term cognition problems following COVID-19 are likely due to fatigue rather than changes in the brain, according to new molecular imaging evidence.
Many people complain of lingering symptoms 12 weeks or longer after coming down with the novel virus. Cognitive ailments—such as brain fog and memory loss—often top the list, but their causes remain a mystery.
Neurology experts in Germany analyzed a small group of patients with long-COVID syndrome who were recommended for PET imaging. They found no meaningful findings on 18F-FDG-PET scans compared to healthy patients, while more than 60% reported experiencing fatigue.
“This suggests that the fatigue, not brain regional dysfunction, may be responsible for many long-COVID symptoms,” Andrea Dressing, with the University of Freiburg’s Brain Imaging Center, and co-authors explained in the Journal of Nuclear Medicine.
Prior research has shown that those requiring inpatient treatment due to COVID-19 have reduced glucose metabolism in the brain, which is commonly linked to impaired cognition.
Dressing et al. further investigated this little-understood connection, performing neuropsychological testing in 31 patients and brain imaging in approximately half of the group.
Each individual sought out neurological counseling after reporting cognition issues more than three months after being diagnosed with COVID-19.
The team found no significant differences between the 14 PET scans and results among the healthy control group. And clinical assessments of each exam showed no pathological findings or alternate diagnoses.
Looking over these results, the experts contrasted the high rate of fatigue reported among patients with mild impairment scores and lack of imaging findings.
They further emphasized that the cognitive symptoms experienced after recovering from the virus may be due to fatigue, rather than changes in brain pathology.
“Although 39% of patients report a relevant disability at work and everyday life due to these symptoms, an exhaustive assessment including a detailed cognitive battery showed only mild impairment in individual patients and cerebral 18F-FDG PET failed to reveal a distinct pathological signature,” the authors wrote.
Read the full study here.
Matt joined Chicago’s TriMed team in 2018 covering all areas of health imaging after two years reporting on the hospital field. He holds a bachelor’s in English from UIC, and enjoys a good cup of coffee and an interesting documentary.