RT Journal Article
SR Electronic
T1 Altered regional cerebral function and its association with cognitive impairment in COVID‑19: A prospective FDG PET study
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP 41
OP 41
VO 62
IS supplement 1
A1 Ganna Blazhenets
A1 Nils Schroeter
A1 Tobias Bormann
A1 Johannes Thurow
A1 Dirk Wagner
A1 Lars Frings
A1 Cornelius Weiller
A1 Andrea Dressing
A1 Jonas Hosp
A1 Philipp Meyer
YR 2021
UL http://jnm.snmjournals.org/content/62/supplement_1/41.abstract
AB 41Objectives: Given the rapid spread of SARS-CoV-2 and emerging evidence of neurological symptoms particularly in hospitalized COVID-19 patients, we prospectively examined the impact of COVID‑19 on the CNS in inpatients at the subacute and the chronic stage by FDG PET and neurological examination. Methods: We assessed neurological and neuropsychological symptoms (Montreal Cognitive Assessment, MoCA, adjusted for years of education) and FDG PET scans in 15 COVID-19 inpatients with at least one new neurological symptom at the subacute stage (once were no longer infectious). All scans were visually read using a 3-step rating scale (normal, mildly and severely abnormal). Principal components analysis (PCA; avoiding the need of a currently unknown reference region) was employed to explore whether a spatial covariance pattern exists in COVID-19 (compared to 45 control patients without somatic CNS disease). In eight of these patients, we re-assessed FDG PET and MoCA performance at the chronic stage approximately six months after symptom onset to examine the time course of post-COVID-19 cognitive impairment. For further validation, we also conducted a conventional group analysis using statistical parametric mapping (SPM) and a white matter as reference region (given the obvious involvement of grey matter in visual analysis). Results: 29 of 41 screened inpatients showed one or more new neurological symptoms and gave written informed consent. Initial hospitalization was done because of medical, not neurological complications; only 2 patients underwent ICU treatment. 18 of 26 (69%, 3 refused) patients showed cognitive impairment defined as MoCA≤26. 15 patients also agreed to undergo FDG PET. Visual reads indicated pathological results (mainly frontoparietal hypometabolism) in 10/15 patients at the subacute stage. We detected a highly significant (p<0.001) COVID-19-related spatial covariance pattern characterized by positive weights in brain stem, cerebellum, white matter and mesiotemporal structures and negative weights in wide-spread neocortical areas (with frontoparietal predominance). Visual reads correlated significantly with the individual pattern expression score (PES) of the COVID‑19‑related pattern (r=0.80, p<0.001) and we found a highly significant linear relationship between MoCA and the PES at the subacute stage (R2=0.62, p<0.001). Conventional SPM analysis also showed wide-spread, frontoparietal dominant neocortical hypometabolism whereas there were no hypermetabolic clusters (false discovery rate [FDR]‑corrected p<0.01). In the eight COVID-19 patients presented for a follow-up, the mean PES at the chronic stage was significantly lower compared to the subacute stage (two-tailed paired t test, p=0.002), but still at trend-level higher in comparison to the control group (one-tailed two-sample t test, p=0.06). In parallel, MoCA significantly improved from 19.1±4.5 at the subacute stage to 23.4±3.6 at the chronic stage (p<0.05), which was however still below normal in 5/8 patients. Group analysis using SPM also showed a wide-spread increase of normalized FDG uptake in frontoparietal and, to a lesser extent, temporal neocortical regions at the chronic stage compared to the subacute stage (FDR‑corrected p<0.01). At an exploratory statistical threshold (p<0.005), there was also a remaining neocortical hypometabolism in COVID-19 patients at the chronic stage compared to the control group. Conclusions: Neocortical dysfunction accompanied by cognitive impairment was detected in two-thirds of inpatients with subacute COVID-19. Although a significant recovery of regional neuronal function and cognition can be clearly stated, residuals are still measurable in some patients six month after manifestation of COVID-19. In consequence, post-COVID-19 patients with persistent cognitive complaints should be presented to a neurologist and possibly allocated to cognitive rehabilitation programs.