title: Self-reported post-exertional fatigue in Gulf War veterans: roles of autonomic testing.
abstract: To determine if objective evidence of autonomic dysfunction exists from a group of Gulf War veterans with self-reported post-exertional fatigue, we evaluated 16 Gulf War ill veterans and 12 Gulf War controls. Participants of the ill group had self- reported, unexplained chronic post-exertional fatigue and the illness symptoms had persisted for years until the current clinical study. The controls had no self-reported post-exertional fatigue either at the time of initial survey nor at the time of the current study. We intended to identify clinical autonomic disorders using autonomic and neurophysiologic testing in the clinical context. We compared the autonomic measures between the 2 groups on cardiovascular function at both baseline and head-up tilt, and sudomotor function. We identified 1 participant with orthostatic hypotension, 1 posture orthostatic tachycardia syndrome, 2 distal small fiber neuropathy, and 1 length dependent distal neuropathy affecting both large and small fiber in the ill group; whereas none of above definable diagnoses was noted in the controls. The ill group had a significantly higher baseline heart rate compared to controls. Compound autonomic scoring scale showed a significant higher score (95% CI of mean: 1.72-2.67) among ill group compared to controls (0.58-1.59). We conclude that objective autonomic testing is necessary for the evaluation of self-reported, unexplained post-exertional fatigue among some Gulf War veterans with multi-symptom illnesses. Our observation that ill veterans with self-reported post-exertional fatigue had objective autonomic measures that were worse than controls warrants validation in a larger clinical series.
authors.affiliation: Department of Veterans Affairs Medical Center, War-Related Illness and Injury Study Center Washington, DC, USA ; Neurology Service, Department of Veterans Affairs Medical Center Washington, DC, USA ; Research Service, Department of Veterans Affairs Medical Center Washington, DC, USA.
authors.forename: Mian
authors.initials: M
authors.lastname: Li
authors.affiliation: Research Service, Department of Veterans Affairs Medical Center Washington, DC, USA.
authors.forename: Changqing
authors.initials: C
authors.lastname: Xu
authors.affiliation: Department of Veterans Affairs Medical Center, War-Related Illness and Injury Study Center Washington, DC, USA ; Research Service, Department of Veterans Affairs Medical Center Washington, DC, USA.
authors.forename: Wenguo
authors.initials: W
authors.lastname: Yao
authors.affiliation: Department of Veterans Affairs Medical Center, War-Related Illness and Injury Study Center Washington, DC, USA ; Research Service, Department of Veterans Affairs Medical Center Washington, DC, USA.
authors.forename: Clare M
authors.initials: CM
authors.lastname: Mahan
authors.affiliation: Department of Veterans Affairs Medical Center, War-Related Illness and Injury Study Center Washington, DC, USA ; Research Service, Department of Veterans Affairs Medical Center Washington, DC, USA.
authors.forename: Han K
authors.initials: HK
authors.lastname: Kang
authors.affiliation: Neurology Service, Department of Veterans Affairs Medical Center Washington, DC, USA.
authors.forename: Friedhelm
authors.initials: F
authors.lastname: Sandbrink
authors.affiliation: Neurology Service, Department of Veterans Affairs Medical Center Washington, DC, USA.
authors.forename: Ping
authors.initials: P
authors.lastname: Zhai
authors.affiliation: Cardiology Service, Department of Veterans Affairs Medical Center Washington, DC, USA.
authors.forename: Pamela A
authors.initials: PA
authors.lastname: Karasik
keywords: Gulf War veteran; autonomic; objective testing; post-exertional fatigue; self-reported symptom