Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) Clinical Normative Data for Gulf War Veterans

Investigating a clinically informed sleep disturbance threshold for physical and mental health among Gulf War Illness veterans

Study Objectives

This study (1) assessed sleep quality and health in Gulf War veterans (GWV) meeting the Gulf War Illness (GWI) criteria and (2) compared health associations for both those meeting a "clinically disturbed sleep" threshold, and those below, as determined by the Pittsburgh Sleep Quality Index (PSQI) cutoff for military populations (≥10) on measures of physical, mental, and cognitive health.

Methods

Participant data consisted of questionnaires and assessments completed prior to group assignment in a clinical trial. The sample consisted of 147 GWV, where 81.0% were males, and the median age was 53.4 years.

Results

The mean (SD) PSQI global score was 12.34 (4.00) with 61% of the sample qualifying as clinically disturbed sleepers according to the cutoff (global PSQI ≥ 10). GWI veterans with PSQI scores ≥10 did not differ from others in age (p = 0.20), sex (p = 0.19), or years of education (p = 0.87), but showed worse GW-related symptomology on the Gulf War Kansas questionnaire (p < 0.01), and poorer mental health on the Veterans Rand-36 (p < 0.01).

Conclusions

Disturbed sleep was associated with measures of pain, fatigue, and cognitive health. Our results suggest that a previously determined clinical threshold for clinically disturbed sleep is useful when examining the health status of the study population. Given that GWI is associated with elevated PSQI scores and a high frequency of disturbed sleep, cutoffs determining sleep health should be sensitive to population exposures and health history to improve interpretability.

Cognitive decrements in 1991 Gulf War veterans: associations with Gulf War illness and neurotoxicant exposures in the Boston Biorepository, Recruitment, and Integrative Network (BBRAIN) cohorts

BACKGROUND

During deployment, veterans of the 1991 Gulf War (GW) were exposed to multiple war-related toxicants. Roughly a third of these veterans continue to exhibit neurotoxicant induced symptoms of Gulf War Illness (GWI), a multi-faceted condition that includes fatigue, pain and cognitive decrements. When studied empirically, both deployed veterans with exposures and those who meet the criteria for GWI are more likely to show deficits in the area of neuropsychological functioning. Although studies have shown cognitive impairments in small sample sizes, it is necessary to revisit these findings with larger samples and newer cohorts to see if other areas of deficit emerge with more power to detect such differences. A group of researchers and clinicians with expertise in the area of GWI have identified common data elements (CDE) for use in research samples to compare data sets. At the same time, a subgroup of researchers created a new repository to share these cognitive data and biospecimens within the GWI research community.

METHODS

The present study aimed to compare cognitive measures of attention, executive functioning, and verbal memory in a large sample of GWI cases and healthy GW veteran controls using neuropsychological tests recommended in the CDEs. We additionally subdivided samples based on the specific neurotoxicant exposures related to cognitive deficits and compared exposed versus non-exposed veterans regardless of case criteria status. The total sample utilized cognitive testing outcomes from the newly collated Boston, Biorepository, Recruitment, and Integrative Network (BBRAIN) for GWI.

RESULTS

Participants included 411 GW veterans, 312 GWI (cases) and 99 healthy veterans (controls). Veterans with GWI showed significantly poorer attention, executive functioning, learning, and short-and-long term verbal memory than those without GWI. Further, GW veterans with exposures to acetylcholinesterase inhibiting pesticides and nerve gas agents, had worse performance on executive function tasks. Veterans with exposure to oil well fires had worse performance on verbal memory and those with pyridostigmine bromide anti-nerve gas pill exposures had better verbal memory and worse performance on an attention task compared to unexposed veterans.

CONCLUSIONS

This study replicates prior results regarding the utility of the currently recommended CDEs in determining impairments in cognitive functioning in veterans with GWI in a new widely-available repository cohort and provides further evidence of cognitive decrements in GW veterans related to war-related neurotoxicant exposures.