Effect of Post-COVID-19 on Brain Volume and Glucose Metabolism: Influence of Time Since Infection and Fatigue Status

Abstract:

Post-COVID-19 syndrome (PCS) fatigue is typically most severe <6 months post-infection. Combining magnetic resonance imaging (MRI) and positron emission tomography (PET) imaging with the glucose analog [18F]-Fluorodeoxyglucose (FDG) provides a comprehensive overview of the effects of PCS on regional brain volumes and metabolism, respectively. The primary purpose of this exploratory study was to investigate differences in MRI/PET outcomes between people < 6 months (N = 18, 11 female) and > 6 months (N = 15, 6 female) after COVID-19.
The secondary purpose was to assess if any differences in MRI/PET outcomes were associated with fatigue symptoms. Subjects > 6 months showed smaller volumes in the putamen, pallidum, and thalamus compared to subjects < 6 months. In subjects > 6 months, fatigued subjects had smaller volumes in frontal areas compared to non-fatigued subjects. Moreover, worse fatigue was associated with smaller volumes in several frontal areas in subjects > 6 months.
The results revealed no brain metabolism differences between subjects > 6 and < 6 months. However, both groups exhibited both regional hypo- and hypermetabolism compared to a normative database. These results suggest that PCS may alter regional brain volumes but not metabolism in people > 6 months, particularly those experiencing fatigue symptoms.
Source: Deters JR, Fietsam AC, Gander PE, Boles Ponto LL, Rudroff T. Effect of Post-COVID-19 on Brain Volume and Glucose Metabolism: Influence of Time Since Infection and Fatigue Status. Brain Sciences. 2023; 13(4):675. https://doi.org/10.3390/brainsci13040675 https://www.mdpi.com/2076-3425/13/4/675 (Full text)

Long COVID: Cognitive and FDG PET evolutions in six patients

Abstract:

Long COVID is often characterized by cognitive complaints and deficits occurring immediately or several weeks after the infectious disease. Neuropsychological tests can revealed attention and executive function anomalies and FDG PET can display hypometabolic areas affecting various regions including frontal and cingulate cortices as well as precuneus and brainstem. We report here the cognitive and FDG PET evolutions over one year in 6 patients suffering from long COVID. Our study shows cognitive and FDG PET improvements in most of the cases and highlight the importance of a careful neurological follow-up in these patients.

Source: Jacques Hugon, Karim Farid, Mathieu Queneau et al. Long COVID: Cognitive and FDG PET evolutions in six patients, 03 April 2023, PREPRINT (Version 1) available at Research Square. https://doi.org/10.21203/rs.3.rs-2703691/v1 https://www.researchsquare.com/article/rs-2703691/v1 (Full text)

Psychiatric and neurological complications of long COVID

Abstract:

COVID-19 was primarily considered a pulmonary disease with extrapulmonary manifestations. As the pandemic spread, there has been growing evidence that the disease affects various organs/systems, including the central and peripheral nervous systems. Accumulation of clinical data demonstrates that in a large population of survivors impairments in the function of one or more organs may persist for a long time, a phenomenon commonly known as post COVID or long COVID.

Fatigue and cognitive dysfunction, such as concentration problems, short-term memory deficits, general memory loss, a specific decline in attention, language and praxis abilities, encoding and verbal fluency, impairment of executive functions, and psychomotor coordination, are amongst the most common and debilitating features of neuropsychatric symptoms of post COVID syndrome. Several patients also suffer from compromised sleep, depression, anxiety and post-traumatic stress disorder. Patients with long COVID may demonstrate brain hypometabolism, hypoperfusion of the cerebral cortex and changes in the brain structure and functional connectivity.

Children and adolescents represent a minority of COVID-19 cases, so not surprisingly data on the long-term sequelae after SARS-CoV-2 infections in these age groups are scarce. Although the pathogenesis, clinical characteristics, epidemiology, and risk factors of the acute phase of COVID-19 have been largely explained, these areas are yet to be explored in long COVID. This review aims to provide an update on what is currently known about long COVID effects on mental health.

Source: Zawilska JB, Kuczyńska K. Psychiatric and neurological complications of long COVID. J Psychiatr Res. 2022 Oct 20;156:349-360. doi: 10.1016/j.jpsychires.2022.10.045. Epub ahead of print. PMID: 36326545; PMCID: PMC9582925. https://www.sciencedirect.com/science/article/pii/S0022395622005982 (Full text)

Brain 18F-FDG PET imaging in outpatients with post-COVID-19 conditions: findings and associations with clinical characteristics

Abstract:

Background: Brain 18F-FDG PET imaging has the potential to provide an objective assessment of brain involvement in post-COVID-19 conditions but previous studies of heterogeneous patient series yield inconsistent results. The current study aimed to investigate brain 18F-FDG PET findings in a homogeneous series of outpatients with post-COVID-19 conditions and to identify associations with clinical patient characteristics.

Methods: We retrospectively included 28 consecutive outpatients who presented with post-COVID-19 conditions between September 2020 and May 2022 and who satisfied the WHO definition, and had a brain 18F-FDG PET for suspected brain involvement but had not been hospitalized for COVID-19. A voxel-based group comparison with 28 age- and sex-matched healthy controls was performed (p-voxel at 0.005 uncorrected, p-cluster at 0.05 FWE corrected) and identified clusters were correlated with clinical characteristics.

Results: Outpatients with post-COVID-19 conditions exhibited diffuse hypometabolism predominantly involving right frontal and temporal lobes including the orbito-frontal cortex and internal temporal areas. Metabolism in these clusters was inversely correlated with the number of symptoms during the initial infection (r = – 0.44, p = 0.02) and with the duration of symptoms (r = – 0.39, p = 0.04). Asthenia and cardiovascular, digestive, and neurological disorders during the acute phase and asthenia and language disorders during the chronic phase (p ≤ 0.04) were associated with these hypometabolic clusters.

Conclusion: Outpatients with post-COVID-19 conditions exhibited extensive hypometabolic right fronto-temporal clusters. Patients with more numerous symptoms during the initial phase and with a longer duration of symptoms were at higher risk of persistent brain involvement.

Source: Goehringer F, Bruyere A, Doyen M, Bevilacqua S, Charmillon A, Heyer S, Verger A. Brain 18F-FDG PET imaging in outpatients with post-COVID-19 conditions: findings and associations with clinical characteristics. Eur J Nucl Med Mol Imaging. 2022 Nov 2. doi: 10.1007/s00259-022-06013-2. Epub ahead of print. PMID: 36322190. https://link.springer.com/article/10.1007/s00259-022-06013-2 (Full text)

Severe posterior hypometabolism but normal perfusion in a patient with CFS/ME

Abstract:

Chronic fatigue syndrome/myalgic encephalitis (CFS/ME) is a complex clinical condition defined by prolonged severe fatigue without medical or psychiatric causes, and by a subset of symptoms that mostly includes arthromyalgias, cognitive impairment, sleeping troubles, and unusual headaches [1]. Previous FDG-PET studies showed unspecific patterns of hypometabolism in the frontal and cingulate cortex in half of CFS patients compared to healthy controls [2].

We present 18F-FDG PET/MRI findings in a 21-year-old woman who fulfilled the criteria of CFS with a Fukuda score of 4. PET images (a) show severe and extensive hypometabolism in the posterior cortical regions (precuneus, parietal, temporal, and occipital), amygdalo-hippocampal complexes, and cerebellum. No structural abnormalities were found on T1 MPRAGE (b) or T2 FLAIR (c) MRI sequences. Interestingly, cerebral blood flow evaluated with Gadolinium first-pass method (d) was not decreased in these regions.

This peculiar pattern of hypometabolism was recently described in a large series of patients with aluminium-induced macrophagic myofasciitis (MMF) followed in our reference center [3]. However, the present patient had negative muscular biopsies for MMF. Neuropsychological testing showed severe impairment of short-term memory (immediate and working memory) in visual modality, and weakness of visual selective attention and executive functions, which are concordant with the pattern of hypometabolism. Finally, perfusion-metabolism uncoupling suggests that posterior hypometabolism may not be related to neuronal loss such as in degenerative diseases [4], but rather to an inflammatory or immunological process [5]. Further studies are warranted to investigate metabolism and perfusion using simultaneous PET/MRI in larger groups of patients with CFS/ME.

Source: S. Sahbai & P. Kauv & M. Abrivard & P. Blanc-Durand & M. Aoun-Sebati & B. Emsen & A. Luciani & J. Hodel & F-J. Authier & E. Itti. Severe posterior hypometabolism but normal perfusion in a patient with chronic fatigue syndrome/myalgic encephalomyelitis revealed by PET/MRI. Eur J Nucl Med Mol Imaging. 2018 Dec 14. doi: 10.1007/s00259-018-4229-3. [Epub ahead of print] https://forums.phoenixrising.me/index.php?threads/severe-posterior-hypometabolism-but-normal-perfusion-in-a-patient-with-cfs-me.62543/