Subcortical and Default Mode Network connectivity is impaired in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a complex chronic condition with core symptoms of fatigue, and cognitive dysfunction suggesting a key role for the central nervous system, in the pathophysiology of this disease. Several studies have reported altered functional connectivity (FC) related to motor and cognitive deficits in ME/CFS patients. In this study, we compared functional connectivity differences between 31 ME/CFS and 15 healthy controls (HC) using 7 Tesla MRI. Functional scans were acquired during a cognitive Stroop color-word task and blood oxygen level-dependent (BOLD) time-series were computed for 27 regions of interest (ROIs) in the cerebellum, brainstem, and salience and default mode networks.

Region-based comparison detected reduced FC between the pontine nucleus and cerebellum vermis IX (p=0.027) for ME/CFS patients compared to HC. Our ROI-to-voxel analysis found significant impairment of FC within ponto-cerebellar regions in ME/CFS. Correlation analyses of connectivity with clinical scores in ME/CFS patients detected associations of FC with ‘duration of illness’ and ‘memory scores’ in salience network hubs and cerebellum vermis, and with ‘respiratory rate’ within medulla and the default mode network FC.

This novel investigation is the first to report extensive involvement of aberrant ponto-cerebellar connections consistent with ME/CFS symptomatology. This highlights the involvement of the brainstem and the cerebellum in the pathomechanism of ME/CFS.

Source: Maira INDERYAS, Kiran Thapaliya, Sonya Marshall-Gradisnik, Markus Barth, Leighton Barnden. Subcortical and Default Mode Network connectivity is impaired in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. Front. Neurosci. Sec. Brain Imaging Methods. Volume 17 – 2023 | doi: 10.3389/fnins.2023.1318094 https://www.frontiersin.org/articles/10.3389/fnins.2023.1318094/full (Full text)

Hypothalamus volumes in adolescent Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Impact of self-reported fatigue and illness duration

Abstract:

Adolescent Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a complex illness of unknown aetiology. Emerging theories suggest ME/CFS may reflect a progressive, aberrant state of homeostasis caused by disturbances within the hypothalamus, yet few studies have investigated this using magnetic resonance imaging in adolescents with ME/CFS.

We conducted a volumetric analysis to investigate whether whole and regional hypothalamus volumes in adolescents with ME/CFS differed compared to healthy controls, and whether these volumes were associated with fatigue severity and illness duration. 48 adolescents (25 ME/CFS, 23 controls) were recruited. Lateralised whole and regional hypothalamus volumes, including the anterior superior, superior tubular, posterior, anterior inferior and inferior tubular subregions, were calculated from T1 weighted images.

When controlling for age, sex and intracranial volume, Bayesian linear regression revealed no evidence for differences in hypothalamus volumes between groups. However, in the ME/CFS group, a negative linear relationship between right anterior superior volumes and fatigue severity was identified, which was absent in controls. In addition, Bayesian ordinal regression revealed a likely-positive association between illness duration and right superior tubular volumes in the ME/CFS group.

While these findings suggest overall comparability in regional and whole hypothalamus volumes between adolescents with ME/CFS and controls, preliminary evidence was identified to suggest greater fatigue and longer illness duration were associated with greater right anterior superior and superior tubular volumes, respectively. These regions contain the anterior and superior divisions of the paraventricular nucleus, involved in the neuroendocrine response to stress, suggesting involvement in ME/CFS pathophysiology. However, replication in a larger, longitudinal cohort is required.

Source: Hollie ByrneElisha K JosevSarah J KnightAdam ScheinbergKatherine RoweLionel LubitzMarc L Seal. Hypothalamus volumes in adolescent Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Impact of self-reported fatigue and illness duration.

The Relationship between Age and Illness Duration in Chronic Fatigue Syndrome

Abstract:

Chronic fatigue syndrome (CFS) is a debilitating illness, but it is unclear if patient age and illness duration might affect symptoms and functioning of patients.

In the current study, participants were categorized into four groups based upon age (under or over age 55) and illness duration (more or less than 10 years). The groups were compared on functioning and symptoms.

Findings indicated that those who were older with a longer illness duration had significantly higher levels of mental health functioning than those who were younger with a shorter or longer illness duration and the older group with a shorter illness duration. The results suggest that older patients with an illness duration of over 10 years have significantly higher levels of mental health functioning than the three other groups.

For symptoms, the younger/longer illness duration group had significantly worse immune and autonomic domains than the older/longer illness group. In addition, the younger patients with a longer illness duration displayed greater autonomic and immune symptoms in comparison to the older group with a longer illness duration.

These findings suggest that both age and illness duration need to be considered when trying to understand the influence of these factors on patients.

 

Source: Kidd E, Brown A, McManimen S, Jason LA, Newton JL, Strand EB. The Relationship between Age and Illness Duration in Chronic Fatigue Syndrome. Diagnostics (Basel). 2016 Apr 22;6(2). pii: E16. doi: 10.3390/diagnostics6020016. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4931411/ (Full article)