Tag: hippocampus

Volumetric differences in hippocampal subfields and associations with clinical measures in myalgic encephalomyelitis/chronic fatigue syndrome

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) patients suffer from a cognitive and memory dysfunction. Because the hippocampus plays a key role in both cognition and memory, we tested for volumetric differences in the subfields of the hippocampus in ME/CFS.

We estimated hippocampal subfield volumes for 25 ME/CFS patients who met Fukuda criteria only (ME/CFSFukuda ), 18 ME/CFS patients who met the stricter ICC criteria (ME/CFSICC ), and 25 healthy controls (HC). Group comparisons with HC detected extensive differences in subfield volumes in ME/CFSICC but not in ME/CFSFukuda . ME/CFSICC patients had significantly larger volume in the left subiculum head (p < 0.001), left presubiculum head (p = 0.0020), and left fimbria (p = 0.004).

Correlations of hippocampus subfield volumes with clinical measures were stronger in ME/CFSICC than in ME/CFSFukuda patients. In ME/CFSFukuda patients, we detected positive correlations between fatigue and hippocampus subfield volumes and a negative correlation between sleep disturbance score and the right CA1 body volume.

In ME/CFSICC patients, we detected a strong negative relationship between fatigue and left hippocampus tail volume. Strong negative relationships were also detected between pain and SF36 physical scores and two hippocampal subfield volumes (left: GC-ML-DG head and CA4 head).

Our study demonstrated that volumetric differences in hippocampal subfields have strong statistical inference for patients meeting the ME/CFSICC case definition and confirms hippocampal involvement in the cognitive and memory problems of ME/CFSICC patients.

Source: Thapaliya K, Staines D, Marshall-Gradisnik S, Su J, Barnden L. Volumetric differences in hippocampal subfields and associations with clinical measures in myalgic encephalomyelitis/chronic fatigue syndrome. J Neurosci Res. 2022 Mar 31. doi: 10.1002/jnr.25048. Epub ahead of print. PMID: 35355311. https://onlinelibrary.wiley.com/doi/10.1002/jnr.25048  (Full study)

The role of the hippocampus in the pathogenesis of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS)

Abstract:

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a severe acquired illness characterized by a profound sensation of fatigue, not ameliorated by rest and resulting in a substantial decrease in the amount and quality of occupational, social and recreational activities.

Despite intense research, the aetiology and pathogenesis of ME/CFS is still unknown and no conclusive biological markers have been found. As a consequence, an accepted curative treatment is still lacking and rehabilitation programmes are not very effective, as few patients recover. Increased knowledge of the mechanisms leading to the emergence and maintenance of the illness is called for.

In this study, I will put forth an alternative hypothesis to explain some of the pathologies associated with ME/CFS, by concentrating on one of the major strategic organs of the brain, the hippocampus. I will show that the ME/CFS triggering factors also impact the hippocampus, leading to neurocognitive deficits and disturbances in the regulation of the stress system and pain perception. These deficits lead to a substantial decrease in activity and to sleep disorders, which, in turn, impact the hippocampus and initiate a vicious circle of increased disability.

Copyright © 2015 Elsevier Ltd. All rights reserved.

 

Source: Saury JM. The role of the hippocampus in the pathogenesis of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). Med Hypotheses. 2016 Jan;86:30-8. doi: 10.1016/j.mehy.2015.11.024. Epub 2015 Nov 27. https://www.ncbi.nlm.nih.gov/pubmed/26804593

 

Resveratrol improves hippocampal atrophy in chronic fatigue mice by enhancing neurogenesis and inhibiting apoptosis of granular cells

Abstract:

Neuroimaging evidence showed structural and/or functional abnormalities existing in the central nervous system, especially the hippocampus, in chronic fatigue syndrome (CFS) patients. However, its pathophysiologic mechanisms are unclear in part due to the lack of an applicable animal model. We established a chronic fatigue murine model by six repeated injections of Brucella abortus antigen to mice, which was manifested as reduced daily running activity and hippocampal atrophy. Thereafter, resveratrol, a polyphenolic activator of sirtuin 1, was used for treatment in this model. Daily running activity was increased by more than 20%, and the hippocampus was enlarged after 4-week resveratrol therapy.

Furthermore, resveratrol inhibited neuronal apoptosis and expression of hippocampal acetylated p53 in the fatigue mice. Resveratrol also improved neurogenesis and expression of brain-derived neurotrophic factor mRNA in the hippocampus. We concluded that repeated injection of B. abortus antigen could induce hypoactivity and hippocampal atrophy in mice. Resveratrol may be effective for improving fatigue symptoms and enlarging the atrophic hippocampus by repressing apoptosis and promoting neurogenesis.

 

Source: Moriya J, Chen R, Yamakawa J, Sasaki K, Ishigaki Y, Takahashi T. Resveratrol improves hippocampal atrophy in chronic fatigue mice by enhancing neurogenesis and inhibiting apoptosis of granular cells. Biol Pharm Bull. 2011;34(3):354-9. https://www.jstage.jst.go.jp/article/bpb/34/3/34_3_354/_article (Full article)

 

Proton magnetic resonance spectroscopy and morphometry of the hippocampus in chronic fatigue syndrome

Abstract:

Seven patients with chronic fatigue syndrome (CFS) were matched with ten healthy control subjects of similar age. Hippocampal volume, obtained from magnetic resonance images using an unbiased method, showed no difference between the two groups, whereas proton magnetic resonance spectroscopy showed a significantly reduced concentration of N-acetylaspartate in the right hippocampus of CFS patients (p = 0.005).

Source: Brooks JC, Roberts N, Whitehouse G, Majeed T. Proton magnetic resonance spectroscopy and morphometry of the hippocampus in chronic fatigue syndrome. Br J Radiol. 2000 Nov;73(875):1206-8. http://www.ncbi.nlm.nih.gov/pubmed/11144799

Demonstration of borna disease virus nucleic acid in a patient with chronic fatigue syndrome

Comment on: Borna disease virus in human brains with a rare form of hippocampal degeneration but not in brains of patients with common neuropsychiatric disorders. [J Infect Dis. 1999]

 

To the Editor

Czygan et al. [1]reported the detection of Borna disease virus (BDV) nucleic acid in 3 cases of a rare form of hippocampal degeneration, whereas the brains of patients with other neuropsychiatric disorders tested negative for BDV. Chronic fatigue syndrome (CFS) is another, more frequently diagnosed neuropsychiatric disease that is associated with BDV infection. However, the published findings are highly controversial. Nakaya et al. [2, 3] and Kitani et al. [4] showed both BDV-specific antibodies and RNA in a high percentage of Japanese patients with CFS. Bode et al. [5]isolated BDV from peripheral blood mononuclear cells (PBMC) of an American patient with CFS; however, in an earlier publication, Bode et al. [6], as well as Evengård et al. [7] and Yamaguchi et al. [8] in recent publications, did not find serologie evidence for BDV in patients with CFS. A possible explanation for the controversial results is that the term “chronic fatigue syndrome” probably includes several similar clinical conditions that may have different etiologies. In the study by Czygan et al. [1], brain tissue samples from patients who had CFS were not included. Unfortunately, none of the BDV sequences of the CFS cases mentioned above are available in the GenBank database.

You can read the rest of this comment here: http://jid.oxfordjournals.org/content/181/5/1860.long

 

Source: Nowotny N, Kolodziejek J. Demonstration of borna disease virus nucleic acid in a patient with chronic fatigue syndrome. J Infect Dis. 2000 May;181(5):1860-2. http://jid.oxfordjournals.org/content/181/5/1860.long (Full article)

 

Neurasthenic fatigue, chemical sensitivity and GABAa receptor toxins

Abstract:

Following observation of fatigue syndromes in people who have been occupationally exposed to pesticides and insecticides which exert their toxicity through the GABAa receptor, we have formulated the hypothesis that fatigue syndromes in general may be secondary to altered sensitivity of the GABAa receptor. We discuss the possible involvement of organochlorine compounds which are widespread in the environment. Organophosphate compounds may have similar toxic effects through damaged cholinergic input to the dentate gyrus of the hippocampus where cholinergic and GABAergic transmission are closely linked.

 

Source: Corrigan FM, MacDonald S, Brown A, Armstrong K, Armstrong EM. Neurasthenic fatigue, chemical sensitivity and GABAa receptor toxins. Med Hypotheses. 1994 Oct;43(4):195-200. http://www.ncbi.nlm.nih.gov/pubmed/7838000