Slow but evident recovery from neocortical dysfunction and cognitive impairment in a series of chronic COVID-19 patients

Abstract

Cognitive impairment is a frequent complaint in coronavirus disease-19 and can be related to cortical hypometabolism on 18 F-FDG PET at the subacute stage. However it is unclear, if these changes are reversible. Methods: We prospectively assessed Montreal Cognitive Assessment (MoCA) and 18 F-FDG PET scans in 8 COVID-19 patients at the subacute (once no longer infectious) and chronic stages (approximately six months after symptom onset). The expression of the previously established COVID-19-related covariance pattern was analyzed at both stages to examine the time course of post-COVID-19 cognitive impairment. For further validation, we also conducted a conventional group analysis. Results: Follow-up 18 F-FDG PET revealed a significant reduction of initial frontoparietal and, to a lesser extent, temporal hypometabolism that was accompanied by significant improvement in cognition. The expression of the previously established COVID-19-related pattern was significantly lower at follow-up and correlated inversely with MoCA performance. However, both 18 F-FDG PET and cognitive assessment suggest a residual impairment. Conclusions: 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. Given the current pandemic situation and tremendous uncertainty concerning the long-term effects of COVID-19, the present study provides novel insights of highest medical and socioeconomic relevance.

Rapid vigilance and episodic memory decrements in COVID-19 survivors

“…Particular impairments were found in attention [6][7][8][9][10][11][12] , memory [6][7][8][10][11][12][13] and executive functions. [10][11][12][14][15][16] More recently, using 18 F-FDG PET, it has been demonstrated that in the most severely affected patients, the degree of cognitive impairment was accompanied by frontoparietal hypometabolism. 10,11 Understandably, most of these small-scale reports have, to date, predominantly focused on symptomatic, hospitalised patients (however see 17 ).…”

“…While many studies employ questionnaires reliant on patients' subjective self-reports, recent investigations have begun to document a wide range of post-COVID-19 cognitive deficits using objective cognitive testing of inpatients. Particular impairments were found in attention [6][7][8][9][10][11][12] , memory [6][7][8][10][11][12][13] and executive functions. [10][11][12][14][15][16] More recently, using 18 F-FDG PET, it has been demonstrated that in the most severely affected patients, the degree of cognitive impairment was accompanied by frontoparietal hypometabolism.…”

“…[10][11][12][14][15][16] More recently, using 18 F-FDG PET, it has been demonstrated that in the most severely affected patients, the degree of cognitive impairment was accompanied by frontoparietal hypometabolism. 10,11 Understandably, most of these small-scale reports have, to date, predominantly focused on symptomatic, hospitalised patients (however see 17 ). But what about individuals who have not been hospitalised and do not report any ongoing symptoms after recovery?…”

Neurologische Manifestationen bei Patienten mit Post-COVID-19-Syndrom

“… Mittels der 18 FDG-PET (Fluordesoxyglukosepositronenemissionstomographie mit [ 18 F]) wurde bei 10 von 15 Long-COVID-Patienten mit neurokognitivem Defizit (weniger als 26/30 Punkte im MoCA[„Montreal cognitive assessment“]-Test) in frontoparietalen Hirnregionen ein Hypometabolismus nachgewiesen [ 5 ]. Beim Follow-up [ 2 ] von 8 Patienten über 6 Monate zeigte sich eine Symptomverbesserung mit weitgehender Normalisierung des Hirnstoffwechsels in der PET. Erfahrungen mit der SARS-1-Pandemie zeigten bereits, dass einzelne Patienten sehr lang anhaltende klinische Beschwerden zurückbehalten können, insbesondere Schmerzen, Fatigue, Depression und Schlafstörungen.…”

Persistierende Beschwerden 6 Monate nach COVID-19 – Erfahrungen aus der COVID-19-Nachsorgeambulanz des Universitätsklinikums Freiburg

“…P-Werte wurden mittels 2-seitigen Fisher's-exact-Tests erhoben. während der Akutphase sind beschrieben und waren nach 6 Monaten teilweise rückläufig[15,16]. Mit der beschriebenen Basisdiagnostik können in vielen Fällen Long-COVID-Beschwerden nicht objektiviert und kausal erklärt werden.…”