Visual Processing, "Noise," and Attention in CFS/ME - What We Do and Do Not Notice

It is always gratifying when researchers use simple and quantifiable tests to confirm a "subjective" symptom of ME/CFS. (Use whichever part of that acronym you prefer.) In this case, Dr. Claire V. Hutchison, a much published researcher at the University of Leicester (GB), and Dr. Stephen Badham, a research fellow at the University of Warwick (GB), combined their interests in visual processing and cognition to come up with an elegant study designed to measure the degree to which people with CFS/ME (we'll reverse it this time) can filter visual "noise." The ability to filter environmental "noise," that is simultaneous audial or visual input from a variety of sources, is one of the most frequently mentioned symptoms of ME and CFS, and one which impairs the ability to process information. These two researchers were able to document that deficit. (See the abstract below.)

Take this test and see how well you do. (I failed. Miserably.)

Patterns of abnormal visual attention in myalgic encephalomyelitis

By C.V. Hutchinson and S.P. Badham

Abstract

Purpose: To experimentally assess visual attention difficulties commonly reported by those with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).

Methods:Twenty-nine ME/CFS patients and 29 controls took part in the study. Performance was assessed using the Useful Field of View (UFOV), a spatial cueing task and visual search.

Results:Patients and controls performed similarly on the processing speed subtest of the UFOV. However, patients exhibited marginally worse performance compared with controls on the divided attention subtest and significantly worse performance on the selective attention subtest. In the spatial cueing task, they were slower than controls to respond to the presence of the target, particularly when cues were invalid. They were also impaired, relative to controls, on visual search tasks.

Conclusions:We have provided experimental evidence for ME/CFS-related difficulties in directing visual attention. These findings support the subjective reports of those with ME/CFS and could represent a potential means to improve diagnosis.

Source: Optom Vis Sci. 2013 Jun;90(6):607-14. doi: 10.1097/OPX.0b013e318294c232. Hutchinson CV, Badham SP. College of Medicine, Biological Sciences and Psychology, University of Leicester, Leicester, Leicestershire; and School of Psychology, University of Warwick, Coventry, United Kingdom.

Brain Injury and Gut Dysbiosis in CFS/ME: Interview with Dr. Byron Hyde and Professor Kenny De Meirleir

Dr. Byron Hyde and Professor Kenny De Meirleir are two of the best-known names in the field of researching CFS/ME. Dr. Hyde is the director of the Nightingale Research Foundation located in Ottawa, Canada. His book, The Clinical and Scientific Basis of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome remains the most comprehensive collection of scientific and clinical studies on CFS/ME ever published.

Professor Kenny De Meirleir is a professor of physiology and internal medicine at the Vrije Universiteit Brussel in Belgium.  Professor De Meirleir has co-authored more than 80 studies on CFS/ME. He was also one of the authors of the International Consensus Criteria, the most accurate case definition for evaluating CFS/ME.  Professor De Meirleir's work is based on the premise that the gut wall in CFS/ME is abnormal, and that bacterial pathogens in the gut must be treated in order for antivirals or other treatments to be effective.

In this interview, conducted in 2008 by Öppna Kanalen Göteborgs Webb-TV (a Swedish open-channel station), Dr. Hyde spoke about CNS involvement. His perspective is that CFS/ME is a form of brain injury. He considers it to be a diffuse injury that results in an inability to handle physical or mental stress. Once the brain is injured, the illness affects all body systems. He does not believe there is a general treatment for CFS/ME. However, he believes there is a great deal of collateral damage that must be treated on an individual basis.

Professor De Meirleir spoke about his approach to treating CFS/ME. He performs normal tests to exclude major diseases, then does a series of tests for viruses, immune system and digestive system function. He believes that there is a predisposition to the disease when there is food intolerance or maldigestion. He considers maldigestion to be a major stress on the immune system, 80% of which is in the gut. When another infection occurs, “your bucket flows over and you go into a state where the immune system never comes to rest.”

In CFS/ME, Professor De Meirleir treats food intolerance first (with diet). Then he treats gut dysbiosis (abnormal gut flora) and helps repair the gut barrier (leaky gut). He says it takes a year to recover gut function. Professor De MeirLeir also spoke at length about subgroups.

While this interview was somewhat shortened, there is a wealth of information here about the possible causes, mechanisms, and treatments for CFS/ME. Highly recommended. 

Original interview posted on:

Öppna Kanalen Göteborgs Webb-TV

http://okgplay.no-ip.org/

More information:

Nightingale Research Foundation

http://www.nightingale.ca/

Contact information for Prof. De Meirleir

http://www.pugilator.com/awareness/prof-dr-kenny-de-meirleir-and-himmunitas/

TheClinical and Scientific Basis of Myalgic Encephalomyelitis/ChronicFatigue Syndrome. Byron A. Hyde, Jay A. Goldstein, P.H. Levine, eds. Nightingale Research Foundation (July 1992)

Chronic Fatigue Syndrome: System Under Stress

ScienceDaily (Nov. 14, 2012) — Australian researchers have discovered for the first time that reduced heart rate variability -- or changes in heart beat timing -- best predicts cognitive disturbances, such as concentration difficulties commonly reported by people with chronic fatigue syndrome (CFS). This adds to the growing body of evidence linking autonomic nervous system imbalance to symptoms of this poorly understood disorder.

The findings are reported in the journal PLoS ONE.


Chronic fatigue syndrome is characterised by medically unexplained, disabling fatigue and neuropsychiatric symptoms of at least six months' duration. The disturbance underlying the symptoms in CFS is still poorly understood.

"We have studied autonomic function in CFS for some time and our findings clearly indicate a loss of integrity in stress-responsive neural and physiological systems in CFS. Patients with this condition are hyper-responsive to challenges arising both from within the body and from the environment," says lead researcher, Associate Professor Ute Vollmer-Conna of the University of New South Wales in Sydney, Australia.

"Even when they sleep, their stress-responsive neural systems are on high alert, signalling that it is not safe to relax. I think this condition may be understood by analogy to post-traumatic stress disorder, just that in CFS the original trauma is most likely a physiological, internal one, such as a severe infection."

In a study of 30 patients with CFS and 40 healthy individuals, UNSW researchers recorded the heart beats of participants (via ECG) and analysed cardiac responses to cognitive challenges, and associations with mental performance outcomes.

The patients with CFS performed with similar accuracy, but they took significantly longer to complete the tests than people without the condition. They also had greater heart rate reactivity; low and unresponsive heart rate variability; and prolonged heart rate-recovery after the cognitive challenge.

Resting heart rate variability (an index of vagus nerve activity) was identified as the only significant predictor of cognitive outcomes, while current levels of fatigue and other symptoms did not relate to cognitive performance.

"This is the first demonstration of an association between reduced cardiac vagal tone and cognitive impairment in CFS. Our findings confirm previous reports of a significant loss of vagal modulation, which becomes particularly apparent when dealing with challenging tasks. The current results are consistent with the notion that CFS represents a 'system under stress'," Associate Professor Vollmer-Conna says.

The findings could lead to new ways to improve cognitive difficulties in people with CFS, including biofeedback assisted retraining of autonomic functioning, the researchers say.

Read the abstract here: http://www.ncbi.nlm.nih.gov/pubmed/23166694

Read the full PLoSONE article here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3498107/

Original ScienceDaily article is here: http://www.sciencedaily.com/releases/2012/11/121115133806.htm

CFS Treatment Guide Website: http://cfstreatmentguide.com