A study of veterans who have Gulf war syndrome shows that moderate exercise can bring about a spectrum of brain imaging abnormalities, which fall into one of two groups. This could mean that this is a more complicated illness than was first thought. The study was published on December 12, 2019, in the journal Brain Communications.
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Gulf War Illness
Gulf War Illness (GWI) is diagnosed in 25% to 30% of veterans who fought in the Gulf war between 1990 and 1991. It is characterized by brain fog, which is a loss of clear memory, pain, and tiredness after moderate exertion. These symptoms may be mistaken for the very similar illness called myalgic encephalomyelitis / chronic fatigue syndrome (ME/CFS).
What causes GWI? The explanations for this mysterious illness range from exposure to neurotoxicants and anticholinergic drugs that target neurons, to liver dysfunction. Oddly people who have never been sent overseas to fight show features of GWI. Again, taking multiple immunizations with exposure to anticholinergic drugs or others that damage the liver could precipitate GWI, via impaired liver function. This causes vitamin A compounds stored in the liver to spill all over the house. This results in toxic hypervitaminosis A. Mitochondrial damage is also proposed to be due to anticholinergic
MRI uses powerful magnetic fields and radio waves to get a detailed image of the internal organs. Functional magnetic resonance imaging, or fMRI, is a way of measuring the activity of the brain by detecting the changes that occur in the blood flow through various regions of the brain. The principle underlying this is that cerebral blood flow is closely related to neuronal activation. Blood flow increases in any brain region when it is being used, in other words.
The current study used fMRI, or functional MRI, to visualize the brains of veterans returned from the Gulf War and showing signs of the syndrome called GWI. The scans showed that one of two different categories of change were seen following exercise – and neither was present in normal patients. This confirms that GWI is a condition associated with measurable level of stress in the brain. The changes seen during this time have sparked interest in multiple forms of therapies that could help future GWI patients.
The researchers looked at the brains of GWI veterans using fMRI before and after moderate exercise. The next day, they repeated the exercise and performed a memory test while the imaging was going on.
The findings showed that all veterans had very similar scans before exercise. The group was now subdivided into those whose heart rates showed racing patterns when they stood up, and those who didn’t. The brain activity in both groups was abnormal but showed distinctive variations between groups.
Following exercise, in the group with heart rate acceleration, brain activity in the cerebellum was markedly reduced. This part of the brain controls fine motor movements, cognitive functions like memory and thinking, pain, and emotion. The other group showed, in contrast, significant increase in brain activity in the part of the brain that regulates the coordination of body movements and chronic pain.
In a control group, no changes occurred with exercise. Researcher Stuart Washington says, “While these findings present new challenges to treating people with Gulf War illness, they also present new opportunities.”
Another researcher, James Baraniuk, in whose Georgetown University Medical Center laboratory the research was carried out, explains the benefit of the research in that it provides a better insight into what actually causes the impaired cognition characteristic of GWI. He says, “Now that different regions of the brain have been associated with two subtypes of GWI, we can study these regions through imaging and other techniques to improve diagnosis and, perhaps, to study future treatments.”
Stuart D Washington, Rakib U Rayhan, Richard Garner, Destie Provenzano, Kristina Zajur, Florencia Martinez Addiego, John W VanMeter, James N Baraniuk, Exercise Alters Cerebellar and Cortical Activity Related to Working Memory in Phenotypes of Gulf War Illness, Brain Communications, , fcz039, https://doi.org/10.1093/braincomms/fcz039