Neurologists investigating the effect of chemicals on troops who served in the Persian Gulf War suggest that soldiers who had several health problems when they got back may also have incurred changes to brain areas that have resulted in impairments to memory and learning.
Roberta White, chair of the department of environmental health at Boston University School of Public Health in Boston, Massachusetts, US, presented early findings of a study she is leading to the American Academy of Neurology’s 59th Annual Meeting which is taking place in Boston this week.
Dr White, who is a neuropsychologist, has been studying the health and psychology of Gulf War soldiers since they started returning from combat in the early 1990s.
In this latest study Dr White and colleagues looked at brain scans and results from cognitive and memory tests given to 36 veterans.
They found that two regions of the brain used during thinking and memory were smaller in those veterans who came back from the war with more than five health problems compared with those who had fewer symptoms.
On average, the soldiers described 5 out of a possible 20 health problems when they were evaluated at Fort Devens, Massachusetts, on their return from the War.
The health problems included: headaches, nausea, forgetfulness, rash on the skin, painful joints and fatigue.
Using MRI scans, Dr White and colleagues found that the brains of the soldiers who had more than 5 health problems were on average smaller in two particular regions: the cortex (5 per cent smaller) and the anterior cingulate gyrus (6 per cent smaller).
The cortex is essentially the outer layer of the brain and affects perception, thinking and memory, and the anterior cingulate gyrus, is deep inside the central part of the brain and is involved in logical thinking.
The scientists found that the soldiers who performed the worst at the memory tests had the most shrinkage in those two brain areas.
The memory test was the California Verbal Learning Test where the soldiers had to memorize a list of 16 items and remember them after a certain period of time during which they are given other things to remember as well. The purpose of the test is to measure the efficiency with which a person can commit a list to memory and then recall it later.
The soldiers with the high symptom profile performed on average between 12 and 15 per cent worse on the test compared to their low symptom colleagues.
Some scientists have suggested that these findings are in line with what one might expect from exposure to toxins like nerve gas and pesticides.
Others, are reserving comment until the final report. Meanwhile Dr White and colleagues say their findings show a statistically significant link between the smaller brain volume, poorer cognitive performance (as measured by the specific tests) and the high as opposed to low symptom profile.
They suggest the physical brain differences could be a differentiating marker of some kind between the high and low health problem groups.
As they stand, these preliminary results do not go far enough to show that exposure to chemicals actually caused reduced brain function in the veterans. They may suggest that some soldiers were predisposed to health problems when they were exposed to the chemicals.
So the next stage is to take into account the kinds of chemicals that the soldiers were exposed to and see how those variables affect the links. These chemicals include agents like: sarin, organophosphates, and benzene.
Dr White alluded to the fact that this kind of research takes time and reminded her audience that it took 20 years to find out about the effects of Agent Orange in the Vietnam War. She has been working on this for only 16.
Click here for the National Gulf War Veterans and Families Association (UK).
Written by: Catharine Paddock
Writer: Medical News Today