hypothalamus – Page 2 – American ME and CFS Society

A brain MRI study of chronic fatigue syndrome: evidence of brainstem dysfunction and altered homeostasis

Abstract:

To explore brain involvement in chronic fatigue syndrome (CFS), the statistical parametric mapping of brain MR images has been extended to voxel-based regressions against clinical scores.

Using SPM5 we performed voxel-based morphometry (VBM) and analysed T(1) – and T(2) -weighted spin-echo MR signal levels in 25 CFS subjects and 25 normal controls (NC). Clinical scores included CFS fatigue duration, a score based on the 10 most common CFS symptoms, the Bell score, the hospital anxiety and depression scale (HADS) anxiety and depression, and hemodynamic parameters from 24-h blood pressure monitoring. We also performed group × hemodynamic score interaction regressions to detect locations where MR regressions were opposite for CFS and NC, thereby indicating abnormality in the CFS group.

In the midbrain, white matter volume was observed to decrease with increasing fatigue duration. For T(1) -weighted MR and white matter volume, group × hemodynamic score interactions were detected in the brainstem [strongest in midbrain grey matter (GM)], deep prefrontal white matter (WM), the caudal basal pons and hypothalamus. A strong correlation in CFS between brainstem GM volume and pulse pressure suggested impaired cerebrovascular autoregulation.

It can be argued that at least some of these changes could arise from astrocyte dysfunction. These results are consistent with an insult to the midbrain at fatigue onset that affects multiple feedback control loops to suppress cerebral motor and cognitive activity and disrupt local CNS homeostasis, including resetting of some elements of the autonomic nervous system (ANS).

Source: Barnden LR, Crouch B, Kwiatek R, Burnet R, Mernone A, Chryssidis S, Scroop G, Del Fante P. A brain MRI study of chronic fatigue syndrome: evidence of brainstem dysfunction and altered homeostasis. NMR Biomed. 2011 Dec;24(10):1302-12. doi: 10.1002/nbm.1692. Epub 2011 May 11. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4369126/ (Full article)

Hypothalamic digoxin, cerebral chemical dominance and myalgic encephalomyelitis

Abstract:

The isoprenoid pathway was assessed in 15 patients with chronic fatigue syndrome. The pathway was also assessed in individuals with differing hemispheric dominance to assess whether hemispheric dominance had any correlation with these disease states.

The isoprenoid metabolites–digoxin, dolichol, and ubiquinone–RBC membrane Na+-K+ ATPase activity, serum magnesium and tyrosine/tryptophan catabolic patterns were assessed. The free-radical metabolism, glycoconjugate metabolism, and RBC membrane composition was also assessed. Membrane Na+-K+ ATPase activity and serum magnesium levels were decreased while HMG CoA reductase activity and serum digoxin levels were increased in myalgic encephalomyelitis (ME). There were increased levels of tryptophan catabolites–nicotine, strychnine, quinolinic acid, and serotonin–and decreased levels of tyrosine catabolites–dopamine, noradrenaline, and morphine in ME. There was an increase in dolichol levels, carbohydrate residues of glycoproteins, glycolipids, total/individual GAG fractions, and lysosomal enzymes in ME. Reduced levels of ubiquinone, reduced glutathione, and free-radical scavenging enzymes, as well as increased lipid peroxidation products and nitric oxide, were noticed in ME.

The biochemical patterns in ME correlated with those obtained in right hemispheric chemical dominance. The role of hypothalamic digoxin and neurotransmitter induced immune activation, altered glycoconjugate metabolism, and resultant defective viral antigen presentation, NMDA excitotoxicity and cognitive dysfunction, and mitochondrial dysfunction related myalgia in the pathogenesis of ME is stressed. ME occurs in individuals with right hemispheric chemical dominance.

Source: Kurup RK, Kurup PA. Hypothalamic digoxin, cerebral chemical dominance and myalgic encephalomyelitis. Int J Neurosci. 2003 May;113(5):683-701. https://ammes.orgwp-admin/post-new.php

Dissociation of body-temperature and melatonin secretion circadian rhythms in patients with chronic fatigue syndrome

Abstract:

Many patients with chronic fatigue syndrome (CFS) display features of hypothalamic dysfunction. We have investigated aspects of circadian rhythmicity, an important hypothalamic function, in 20 CFS patients and in 17 age- and sex-matched healthy control subjects.

There were no differences between the two groups in the amplitude, mesor (mean value) or timing of the peak (acrophase) of the circadian rhythm of core temperature, or in the timing of the onset of melatonin secretion.

However, the CFS patients showed no significant correlation between the timing of the temperature acrophase and the melatonin onset (P < 0.5), whereas the normal significant correlation was observed in the controls (P < 0.05). Dissociation of circadian rhythms could be due to the sleep deprivation and social disruption, and/or the reduction in physical activity which typically accompany CFS.

By analogy with jet-lag and shift-working, circadian dysrhythmia could be an important factor in initiating and perpetuating the cardinal symptoms of CFS, notably tiredness, impaired concentration and intellectual impairment.

Source: Williams G, Pirmohamed J, Minors D, Waterhouse J, Buchan I, Arendt J, Edwards RH. Dissociation of body-temperature and melatonin secretion circadian rhythms in patients with chronic fatigue syndrome. Clin Physiol. 1996 Jul;16(4):327-37. http://www.ncbi.nlm.nih.gov/pubmed/8842569

Chronic fatigue syndrome update. Findings now point to CNS involvement

Abstract:

Neither Epstein-Barr virus nor human herpesvirus 6 appears to play a causative role in chronic fatigue syndrome. The possibility that a novel human retrovirus may be present in patients with the syndrome needs further study. A number of abnormalities found in patients with chronic fatigue syndrome point to central nervous system (CNS) involvement. These include immunologic abnormalities, indications of pituitary and hypothalamic involvement, abnormal basal plasma levels of certain neurotransmitter metabolites, and cerebral perfusion abnormalities. The symptom pattern of chronic fatigue syndrome may eventually be explainable in terms of CNS dysfunction.

Source: Bell DS. Chronic fatigue syndrome update. Findings now point to CNS involvement. Postgrad Med. 1994 Nov 1;96(6):73-6, 79-81. http://www.ncbi.nlm.nih.gov/pubmed/7971614

Enteroviruses and postviral fatigue syndrome

Abstract:

Postviral fatigue syndrome (PFS) occurs both in epidemics and sporadically. Many of the original epidemics were related to poliomyelitis outbreaks which either preceded or followed them.

The core clinical symptoms are always the same: severe fatigue made worse by exercise, myalgia, night sweats, atypical depression and excessive sleep. The other common symptoms include dysequilibrium disorders and irritable bowel syndrome.

We have detected enteroviral genome sequences in muscle biopsies from cases of PFS, using specific enteroviral oligonucleotide primers in the polymerase chain reaction (PCR). In addition, whole virus particles can be demonstrated in PCR-positive muscle, using solid-phase immuno-electron microscopy.

An increase in the number and size of muscle mitochondria was found in 70% of PFS cases, suggesting an abnormality in metabolic function. Evidence of hypothalamic dysfunction was present, particularly involving 5-hydroxytryptamine metabolism.

A putative model of PFS, based on persistent enteroviral infection in laboratory mice, revealed resolving inflammatory lesions in muscle with, however, a marked increase in the production of certain cytokines in the brain. This model may help to explain the pathogenesis of PFS.

Source: Behan PO, Behan WM, Gow JW, Cavanagh H, Gillespie S. Ciba Found Symp. 1993;173:146-54; discussion 154-9. http://www.ncbi.nlm.nih.gov/pubmed/8387908

Postviral fatigue syndrome

Comment on: Possible upregulation of hypothalamic 5-hydroxytryptamine receptors in patients with postviral fatigue syndrome. [BMJ. 1992]

EDITOR, -A M 0 Bakheit and colleagues recently reported’ a possible upregulation of hypothalamic 5-hydroxytryptamine receptors in patients with the postviral fatigue syndrome, giving some evidence for hypothalamic functional abnormalities in these patients, which are different from others with depression. There is a growing body of evidence which claims that this clinical condition is organic and cannot be simply perceived as a somatisation disorder in patients with predisposition to psychiatric disease.”

We reviewed and quantitatively analysed with Ceretec and single photon emission tomography the brain perfusion of 14 patients fulfilling the Oxford criteria for diagnosis of myalgic encephalomyelitis. They had all had disease for more than six months (more than half the time) manifested with generalised malaise and myalgia, as well as significant physical and intellectual disability. None had any medical condition known to produce fatigue or had recently or in the past had psychiatric disease. When compared with a group of 24 nondepressed age and sex matched controls (normal volunteers) there was significant reduction of the perfusion to several areas of the brain cortex but particularly the brain stem (table).

You can read the rest of this comment here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1882397/pdf/bmj00077-0053b.pdf

Source: Costa DC, Brostoff J, Douli V, Ell PJ. Postviral fatigue syndrome. BMJ. 1992 Jun 13;304(6841):1567. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1882397/

Postviral fatigue syndrome

Comment on: Possible upregulation of hypothalamic 5-hydroxytryptamine receptors in patients with postviral fatigue syndrome. [BMJ. 1992]

EDITOR,-A M 0 Bakheit and colleagues report an enhanced prolactin response to buspirone in patients with postviral fatigue syndrome and suggest this may be due to upregulation of hypothalamic 5-hydroxytryptamine receptors. They fail to mention the considerable evidence indicating that the drug is a moderately potent dopamine antagonist, a pharmacological action which suggests an alternative explanation for their data.

They administered a single 60 mg dose of buspirone-in excess of the daily maximum of 45 mg recommended by the British National Formulary-so antidopaminergic effects may well have been significant in their studies. The fact that the prolactin releasing effect of buspirone can be blocked by the drug metergoline does not prove 5-hydroxytryptamine receptor specificity. Indeed, metergoline is used commonly as an alternative dopamine agonist to bromocriptine in managing hyperprolactinaemia. Thus enhanced prolactin release after buspirone in postviral fatigue syndrome may reflect, at least in part, inhibition of increased hypothalamic dopaminergic tone on the It would be interesting to study the same groups of patients using a specific D2 dopamine antagonist (such as domperidone) to see whether this is the case.

You can read the rest of this comment here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1882431/pdf/bmj00077-0052d.pdf

Source: Bevan JS. Postviral fatigue syndrome. BMJ. 1992 Jun 13;304(6841):1566; author reply 1567. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1882431/

Possible upregulation of hypothalamic 5-hydroxytryptamine receptors in patients with postviral fatigue syndrome

Abstract:

OBJECTIVE: To study the dynamic function of hypothalamic 5-hydroxytryptamine receptors in patients with postviral fatigue syndrome.

DESIGN: Prospective comparison of patients with postviral fatigue syndrome with two control groups.

SETTING: Department of neurology, University of Glasgow, Southern General Hospital; department of psychiatry, St James’s Hospital, Dublin.

SUBJECTS: 15 patients with postviral fatigue syndrome, 13 age and sex matched healthy subjects, and 13 patients with primary depression.

MAIN OUTCOME MEASURES: Serum prolactin concentrations before and one, two, and three hours after administration of buspirone.

RESULTS: Because of the effects of sex hormones on prolactin secretion data for men and women were analysed separately. There was no significant difference in baseline prolactin concentrations between patients with postviral fatigue syndrome and healthy subjects or those with primary depression. However, the percentage difference between peak and baseline values was significantly higher in patients with postviral fatigue syndrome than the control groups (one way analysis of variance: women, p = 0.003; men, p = 0.004).

CONCLUSIONS: The results suggest upregulation of hypothalamic 5-hydroxytryptamine receptors in patients with postviral fatigue syndrome but not in those with primary depression. The buspirone challenge test may therefore be useful in distinguishing these two conditions. Larger studies are required to explore the potential value of drugs acting on central 5-hydroxytryptamine receptors in the treatment of patients with the postviral fatigue syndrome.

Comment in:

Postviral fatigue syndrome. [BMJ. 1992]

Source: Bakheit AM, Behan PO, Dinan TG, Gray CE, O’Keane V. Possible upregulation of hypothalamic 5-hydroxytryptamine receptors in patients with postviral fatigue syndrome.BMJ. 1992 Apr 18;304(6833):1010-2. http://www.ncbi.nlm.nih.gov/pubmed/1586780

Note: You can read the full article here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1881733/

Hypothesis: cytokines may be activated to cause depressive illness and chronic fatigue syndrome

Abstract:

Abnormalities in the regulation of the hypothalamo-pituitary-adrenal (HPA) axis are a well recognised feature of endogenous depression. The mechanism underlying this phenomenon remains obscure although there is strong evidence suggesting excessive CRH activity at the level of the hypothalamus.

We propose a novel hypothesis in which we suggest that the aetiological antecent to CRH hyperactivity is cytokine activation in the brain. It is now well established both that interleukins -1 and -6 are produced in a number of central loci and that cytokines are potent stimulators of the HPA axis.

Hence, we suggest that activation of IL-1 and IL-6 by specific mechanisms (such as neurotropic viral infection) in combination with the consequent CRH-41 stimulation, may (via their known biological effects) underly many of the features found in major depression and other related disorders, particularly where chronic fatigue is a prominent part of the symptom complex.

This theory has considerable heuristic value and suggests a number of experimental stratagems which may employed in order to confirm or reject it.

Source: Ur E, White PD, Grossman A. Hypothesis: cytokines may be activated to cause depressive illness and chronic fatigue syndrome. Eur Arch Psychiatry Clin Neurosci. 1992;241(5):317-22. http://www.ncbi.nlm.nih.gov/pubmed/1606197