Gulf War Illness Sufferers Show Brain Changes Linked to Memory Loss
Oct. 24, 2013
The study, published in Clinical Psychological Science, confirms Gulf War Illness deficits in working memory, a critical cognitive function that enables short-term retention of information for higher-level thinking ability.
New research shows brain changes in troops with Gulf War Illness, which is thought to have been caused by exposure to neurotoxic chemicals during the first Persian Gulf War.
“More than 250,000 troops, or approximately 25 percent of those deployed during the first Persian Gulf War, have been diagnosed with Gulf War Illness. Although medical professionals have recognized the chronic and often disabling illness for almost two decades, brain changes that uniquely identify (the illness) have been elusive until now,” said principal investigator Bart Rypma, of the Center for BrainHealth at UT Dallas.
This study, published in Clinical Psychological Science, a journal of the Association for Psychological Science, is novel in that it confirms Gulf War Illness (GWI) deficits in working memory, a critical cognitive function that enables short-term retention of information for higher-level thinking ability. In addition, brain alterations revealed in the study show a consistent pattern representing a neurobiological marker that could potentially be used to positively identify the illness.
“These results support an empirical link between exposure to neurotoxic chemicals, specifically sarin nerve gas, with cognitive deficits and neurobiological changes in the brain.”
The research team assessed three aspects of working memory: accuracy, speed and efficiency. Results showed that participants with Gulf War Illness performed significantly slower and less accurately than matched healthy veterans, and their efficiency decreased with increasing task difficulty. During these difficult conditions, the participants showed relatively lower levels of activity in prefrontal brain regions, which may compromise their ability to use higher-level thinking strategies in cognitively demanding situations.
Rypma said the results revealed that soldiers with the illness have working memory deficits that correlate with brain changes that can be seen in brain scans.
“These results support an empirical link between exposure to neurotoxic chemicals, specifically sarin nerve gas, with cognitive deficits and neurobiological changes in the brain,” said Rypma.
He said steps to improve working memory might help patients in their daily lives, perhaps allowing them to finish a shopping list, match names with faces or improve their moods.
“Difficulty remembering has been the most common, unexplained impairment resulting from service in the 1991 Persian Gulf War,” said Robert Haley, co-investigator and chief of epidemiology at UT Southwestern Medical Center in Dallas. “This functional MRI study provides the first objective evidence showing the exact malfunctions in the brain’s memory circuits that underlie these chemically induced memory problems.”
The new findings may also have implications for the treatment of other disorders involving similar neural systems, including one type of Alzheimer’s disease.
“Both GWI and Alzheimer’s disease result in profound cognitive impairment and share similar neurochemical underpinnings,” said Nicholas Hubbard, the study’s lead author. “The distinct neural markers associated with cognitive performance and GWI revealed in our study can be useful for future research to objectively measure the efficacy of treatments for GWI as well as other brain disorders related to the same neurotransmitter system, like Alzheimer’s disease.”