Interesting question about dementia in ME CFS.
There was a study I read ages ago saying that some people with ME CFS have the equivalent cognitive defects as people diagnosed with mild dementia.
It cannot be a co-incidence there is HIV/AIDS dementia, and ME CFS dementia - which may become XMRV/XAND dementia. Both retro-viruses.
Brainfog - may well be brain damage.
It appears to be universal in ME CFS diagnosed with strict Canadian critera.
(Not Reeves disease).
I was hoping it was caused by hypo-perfusion (reduced blood flow) via lactate that could be reversed, however maybe the reality is that XMRV causes increased lactate and hypo perfusion through infecting the brain/circulatory system.
I've read about raised brain
carbon dioxide in ME CFS brains post exercise, and decreased glucose metabolism. This would explain the phenomena of PWC's appearing to have low blood glucose 'hypo' symptoms - yet rarely having a BM under 4.0. However this BM is taken in your finger tip and not the brain. What if PWC's have a unique low blood glucose level in their brains. (Hence never being believed, or proven to have clinical hypo's).
Presumably, if neurons are not fed enough nutrients from blood (e.g. glucose and oxygen) they die off - inducing memory impairment and cognitive deficits?
My own neuro cognitive testing says slightly below average IQ - which is strange as I can perform well at degree level academic work, and thus could not possibly have below average IQ per se - however my cognitive skills are poor - thus validating the test I had show my brain is 'brain fogged' - but what is brain fog?
I hate that word personally - it's baby talk and makes ME CFS sound like a hangover, rather than a serious neuro immune disease.
Brain damaged is more like it. Indeed I specifically remember reading a study that declared from neuro imaging, ME CFS had evidence of 'derangement of the brain'. There's been research showing loss of brain matter in ME CFS and shrinkage also. Oxidative stress? I think off hand it was 17% brain matter loss - which would very much impair thinking ability (memory).
With no tests - we where and remain powerless to diagnose and understand our terrible disease we battle 24/7.
EDIT - the research:
----------------------------------------------------------------
Patients suffering from chronic fatigue syndrome (CFS) do so
because of cerebral function abnormalities as a result of
diminution of brain blood flow, says a California nuclear
medicine specialist. - Dr Ismael Mena of the Harbor-UCLA
Center in Los Angeles said:
"All adult patients with chronic fatigue have abnormal diminution
of blood flow to different areas of the brain - mostly in the frontal
lobes."
The Medical Post, January 19, 1993
-----------------------------------------------------------------
*....SPECT scans in AIDS patients were discussed at the
1992 international AIDS meeting (in Amsterdam) by a
research team from the Houston Immunological Institute.
Rather shockingly, they found that exactly the same
percentage of AIDS patients -- 71 percent -- as CFS
patients had abnormalities in brain blood flow....*
Summary: "This study shows that
CFS (ME) shares some
similarities on SPECT imaging with AIDS Dementia Complex -
acute changes in radionuclide uptake in the younger population
may be caused by inflammatory processes at the cellular or
micro vascular level .... the findings in CFS (ME) face are
consistent with the hypothesis that CFS (ME) ... results from a
viral infection of neurons, glia or vasculature .....viral infection can
provoke neurological dysfunction by interfering with intra-cellular
mechanisms or membrane transport systems .... or by cerebral
hypo perfusion due to vasculitis".
Neurological Dysfunction in Chronic Fatigue Syndrome, Journal
of Chronic Fatigue Syndrome (The Haworth Medical Press, an
imprint of The Haworth Press, Inc.) Vol. 6, No. 3/4, 2000, pp.
51-68. Abhijit Chaudhuri, DM, MD, MRCP; Peter 0. Behan, DSc,
MD, FACP, FRCP
"SPECT Imaging of the Brain: Comparison of Findings in
Patients with Chronic Fatigue Syndrome, AIDS Dementia
Complex, and Major Unipolar Depression," Richard B.
Schwartz, Anthony L. Komaroff, Basem M. Garada, Marcy Gleit,
Teresa H. Doolittle, David W. Bates, Russell G. Vasily, B.
Leonard Holman; American Journal of Roentgenology, Vol 162,
943-951, Copyright 1994 by American Roentgen Ray Society.
Summary: "This study shows that CFS (ME) shares some
similarities on SPECT imaging with AIDS Dementia Complex -
acute changes in radionuclide uptake in the younger population
may be caused by inflammatory processes at the cellular or
micro vascular level .... the findings in CFS (ME) face are
consistent with the hypothesis that CFS (ME) ... results from a
viral infection of neurons, glia or vasculature .....viral infection can
provoke neurological dysfunction by interfering with intra-cellular
mechanisms or membrane transport systems .... or by cerebral
hypo perfusion due to vasculitis".
--------------------------------------------------------------
''We found that patients with chronic fatigue syndrome had
reduced gray-matter volume
in the bilateral prefrontal cortex. Within these areas, the volume reduction in the right prefrontal cortex
paralleled the severity of the fatigue of the subjects.''
http://www.biomedcentral.com/1471-2377/4/14
Some research to look at:
Gordon R et al. Cortical motor potential alterations in chronic
fatigue syndrome. Int J Molec Med. 1999; 4: 493-99.
Proton magnetic resonance spectroscopy of basal ganglia in
chronic fatigue syndrome. Chaudhuri A, Condon BR, Gow JW,
Brennan D, Hadley DM. Neuroreport. 2003 Feb 10;14(2):225-8.
Costa DC, Brostoff J, Douli V, Eli PJ. Brainstem hypoperfusion
in patients with Myalgic Encephalomyelitis-Chronic Fatigue
Syndrome. Eur J Nucl Med 1992 19:733.
Brainstem perfusion is impaired in chronic fatigue syndrome.
DC Costa, C Tannock and J Brostoff. Quarterly Journal of
Medicine December 1995:88:767-773)
Relationship of brain MRI abnormalities and physical functional
status in chronic fatigue syndrome Cook DB, Natelson BH. Int J
Neurosci 2000:107: ( 1-2) :1-6
Brain positron emission tomography (PET) in chronic fatigue
syndrome: preliminary data Tirelli U et al. Am J Med 1998:105:
(3A):54S-58S
Brain MRI abnormalities exist in a subset of patients with chronic
fatigue syndrome. Lange G, DeLuca J, Maldjian JA, Lee H,
Tiersky LA, Natelson BH. J Neurol Sci. 1999 Dec 1;171(1):3-7.
Chronic fatigue syndrome--aetiological aspects. Dickinson CJ.
Eur J Clin Invest. 1997 Apr;27(4):257-67
Brain MR in chronic fatigue syndrome. Greco A, Tannock C,
Brostoff J, Costa DC. AJNR Am J Neuroradiol. 1997 Aug;18(7):
1265-9.
Relationship of brain MRI abnormalities and physical functional
status in chronic fatigue syndrome. Cook DB, Lange G, DeLuca
J, Natelson BH. Int J Neurosci. 2001 Mar 107 (1-2) :1-6.
Quantitative assessment of cerebral ventricular volumes in
chronic fatigue syndrome. Lange G, Holodny AI, DeLuca J, Lee
HJ, Yan XH, Steffener J, Natelson BH. Appl Neuropsychol.
2001;8(1):23-30.