• Welcome to Phoenix Rising!

    Created in 2008, Phoenix Rising is the largest and oldest forum dedicated to furthering the understanding of and finding treatments for complex chronic illnesses such as chronic fatigue syndrome (ME/CFS), fibromyalgia (FM), long COVID, postural orthostatic tachycardia syndrome (POTS), mast cell activation syndrome (MCAS), and allied diseases.

    To become a member, simply click the Register button at the top right.

Restricted Spatial Windows of Visibility in ME: Hutchinson et al: Jan 17th

Countrygirl

Senior Member
Messages
5,395
Location
UK
http://www.mdpi.com/2411-5150/2/1/2/htm


Restricted Spatial Windows of Visibility in Myalgic Encephalomyelitis (ME)
Nadia S. Ahmed, Irene Gottlob, Frank A. Proudlock and Claire V. Hutchinson *

Department of Neuroscience, Psychology and Behaviour, College of Life Sciences, University of Leicester, Leicester LE1 7RH, UK
*
Correspondence:
Received: 22 November 2017 / Accepted: 11 January 2018 / Published: 17 January 2018

Abstract

:
Myalgic encephalomyelitis (ME) is a devastating disorder marked by debilitating fatigue. It not well understood and its diagnosis is controversial. It is very important therefore that significant clinical features are investigated. Visual symptoms in ME represent a group of distinct, quantifiable, clinical features that could significantly improve diagnosis and provide insights into underlying pathology. The purpose of the present study was therefore to explore the effect of ME on spatial windows of visibility using the spatial contrast sensitivity function. Contrast sensitivity was determined for stationary luminance-defined sinusoidal gratings spanning a five-octave range of spatial frequencies (0.5 to 16 c/deg) in a group of 19 individuals with ME and a group of 19 matched (age, gender) controls. Compared to controls, the ME group exhibited a restricted spatial window of visibility for encoding stimulus contrast. This was characterised principally by a contrast sensitivity deficit at lower spatial frequencies and a narrower bandwidth. Our findings suggest that contrast sensitivity deficits may represent a visual marker of ME, and be indicative of abnormal visual processing at the level of the retina and in the cortical and subcortical visual pathways.

Keywords:
contrast sensitivity; myalgic encephalomyelitis; chronic fatigue syndrome; spatial vision; visual psychophysics; windows of visibility
 

Tally

Senior Member
Messages
367
Can someone translate this? :oops:
I don't get what it is different about our vision.
 

Hip

Senior Member
Messages
17,796
My understanding is that visual contrast sensitivity is more a diagnostic criteria for mold / biotoxin illness (ie, Richie Shoemakers chronic inflammatory response syndrome, or CIRS) rather than ME/CFS.

There is a free online visual contrast sensitivity (VCS) test that you can take here. It takes about 5 minutes to do this test online.

When I've taken this VCS test, my contrast sensitivity comes out as pretty good; but my ME/CFS did not appear to involve any mold / biotoxin exposure.

Dr Ritchie Shoemaker used the visual contrast sensitivity to help diagnose mold / biotoxin illness. Note however that a positive VCS test result may also occur in Lyme disease, Babesia, diabetes, Parkinson's and Alzheimer's.



So I don't understand why this study found ME/CFS patients have poor visual contrast sensitivity, unless there happened to be quite a few CIRS patients in the study cohort.
 
Last edited:

alicec

Senior Member
Messages
1,572
Location
Australia
My understanding is that visual contrast sensitivity is more a diagnostic criteria for mold / biotoxin illness (ie, Richie Shoemakers chronic inflammatory response syndrome, or CIRS) rather than ME/CFS.

Well Shoemaker may claim that but where is the evidence for this or other of his inflated claims which seem primarily designed to attract paying patients?

The paper gives 10 references for studies about visual problems in CFS and I recall an earlier thread which discussed an interesting recent study.

Why dismiss all these in favour of self-promoting claims which lead nowhere much when you try to find their evidential base?
 

Hip

Senior Member
Messages
17,796
Well Shoemaker may claim that but where is the evidence for this or other of his inflated claims which seem primarily designed to attract paying patients?

I have not looked into the evidence base for the VCS-biotoxin association. I believe Hudnell published research on decreased visual contrast sensitivity in biotoxin illness. One of his studies is here.

Why do you say that Dr Shoemaker is making inflated claims? He seems to have done a good job in bringing a greater understanding and awareness of biotoxin illnesses.



The paper gives 10 references for studies about visual problems in CFS and I recall an earlier thread which discussed an interesting recent study.

Visual problems do not necessarily equate to decreased visual contrast sensitivity, which is a very specific visual deficit.

Blurred vision is common in ME/CFS, but that is not the same as VCS issues.



I am not dismissing this new study; but there are questions that need to be answered with it. We know that Dr Brewer's studies found a link between mold exposure and ME/CFS, so the distinction between ME/CFS and biotoxin illness may not be so clearcut.
 

alicec

Senior Member
Messages
1,572
Location
Australia
I have not looked into the evidence base for the VCS-biotoxin association. I believe Hudnell published research on decreased visual contrast sensitivity in biotoxin illness.

Hudnell simply showed there was decreased VCS in cases of PEAS (possible estuary associated syndrome), thought to be due to a biotoxin produced by dinoflagellate blooms.

There is no evidence base that I could find for the claim that decreased VCS is diagnostic of biotoxin illness or mould exposure.

Lots of things appear to affect VCS. Here is a paper looking at VCS affected by chemical exposure. Here is a website talking about the various conditions in which VCS testing might be helpful.

Why do you say that Dr Shoemaker is making inflated claims? He seems to have done a good job in bringing a greater understanding and awareness of biotoxin illnesses.

Apart from finding there is nothing specific diagnostically for VCS testing, I first became suspicious of Shoemaker when I tried to find out more about this small, lipid soluble biotoxin which cholestyramine removes and which he claimed was the common culprit in the various biotoxin illnesses he was claiming to treat.

He had published nothing on it, nor had anyone else that I could find. Instead I found the different organisms involved produced a variety of toxins, none of which corresponded to his mysterious substance, or alternatively the toxin had not been characterised.

What finished it for me was his claims for HLA testing which would determine if an individual were particularly susceptible to mould-related illness.

The haplotype research behind this test was really poor. He compared the HLA types of his local patients to international rates. That is quite inappropriate due to the wide variation in HLA type based on ethnic origins.

The HLA types he found in his patients were simply a normal representation of North American HLA types. Accordingly, based on his claims nearly all North Americans would be extra susceptible to different diseases.

I couldn't take anything he said seriously after that and I haven't bothered to follow what he is doing or saying recently.

I certainly don't consider his claims to be a comparative standard against which others should be judged.
 

Hip

Senior Member
Messages
17,796
@alicec
I'd have to look into those criticisms myself if I wanted to come to my own conclusions about them; but even if we assume these criticisms are correct and valid, are you suggesting that we should discount Dr Shoemaker's entire body of work just on that basis?

To my knowledge, nobody else has done anywhere near as much work in bringing mold and biotoxin induced illness into awareness, and developing effective treatments for such illnesses. Indeed, Shoemaker has claimed that these biotoxins create a particular illness which he calls CIRS (chronic inflammatory response syndrome).

I read one interesting story of a patient Ryan who was misdiagnosed with ME/CFS for 10 years, but then found he has CIRS instead, and through Shoemaker's protocol was back to near full health in just 5 months. I wrote a post about that here. ME/CFS patients would be advised to make themselves aware of CIRS, because if they have CIRS but are misdiagnosed with ME/CFS, like Ryan they may be getting the wrong treatment and so not recover.


Certainly I would like to see independent research and validation of CIRS; but as we know, in these sort of syndromes, there is never enough research funding interest.
 
Last edited: