Amyotrophic Lateral Sclerosis Among Veterans Deployed in Support of Post-9/11 U.S. Conflicts.

Introduction Amyotrophic lateral sclerosis (ALS) is a recognized military service-connected condition. Prior prevalence studies of ALS among U.S. war Veterans were not able to address concerns related to neurodegenerative sequelae of traumatic brain injury (TBI) and disregarded risk heterogeneity from occupational categories within service branches. Materials and Methods We identified the prevalence of definite and possible ALS and cumulative incidence of definite ALS among Post-9/11 U.S. Veterans deployed in support of Post-9/11 conflicts (mean age 36.3) who received care in the Veterans Health Administration during fiscal years 2002-2015. Using a case-control study design, we also evaluated the association of TBI and major military occupation groups with ALS adjusting for demographics and comorbidities. Results The prevalence of ALS was 19.7 per 100,000 over 14 years. Both prevalence and cumulative incidence of definite ALS were significantly higher among Air Force personnel compared to other service branches and among tactical operation officers and health care workers compared to general and administrative officers. Neither TBI nor younger age (<45 years) was associated with ALS. Depression, cardiac disease, cerebrovascular disease, high blood pressure, and obstructive sleep apnea were clinical comorbidities significantly associated with ALS in this population of Veterans. Conclusion This study among a cohort of relatively young Veterans showed a high ALS prevalence, suggesting an early onset of ALS among deployed military service members. The higher prevalence among some military specific occupations highlights the need to determine which occupational exposures specific to these occupations (particularly, Air Force personnel, tactical operations officers, and health care workers) might be associated with early onset ALS.