When considering the diseases that United States veterans are burdened with, you might think of COPD, Type 2 Diabetes, certain cancers, post-traumatic stress disorder, and depression. However, there is another disease diagnosed at twice the rate in veterans compared to the general population: amyotrophic lateral sclerosis (ALS). ALS is one of the only diseases known to occur at an increased rate in all veterans, regardless of when or how long they served. Additionally, the mortality rate from ALS is greater among U.S. men with a history of military service. Unfortunately, ALS is hard to diagnose, which results in delays in care. This association between military service and ALS is only just starting to be recognized by physicians and patients alike. Bridging this gap can lead to quicker diagnoses and faster referrals to supportive resources, ultimately improving the quality of life for patients and their families. But what is causing this disproportionate prevalence of ALS in veterans, and what can U.S. veterans with ALS and their providers do about it?

The first question to be answered is: What is ALS? ALS is a condition characterized by motor neuron degeneration, which causes reduced muscle movement. Most patients usually present with asymmetric limb weakness. This can progress to include muscle tightness, paralysis, and eventual death, primarily due to respiratory failure. The average life expectancy after diagnosis is a mere two to five years, a grim statistic that has remained unchanged since the disease was first identified. Symptoms start off subtly, then gradually progress to a tragic loss of independence and the ability to maintain basic life functions. One Fresno, California, veteran’s story, posted on the ALS Association’s Wall of Honor, describes the U.S. Marine’s rapid decline. Sgt. Elpidio S. Muñoz Jr. served as a radio relay operator during the Vietnam War from 1967 to 1971. In 2022, after two years of progressive weakness and just 16 days after an official diagnosis of ALS, Sgt. Muñoz Jr. succumbed to the disease. There is no cure for ALS, but there are resources to lessen its burden on patients, as well as treatments that can delay the disease’s progression. Sadly, the delay in diagnosis in Sgt. Muñoz’s case meant he had little time to take advantage of such resources.

So, what is causing the increased prevalence of ALS in military veterans? While about 10 percent of ALS diagnoses can be attributed to genetic factors, the remaining 90 percent have sporadic or nonspecific onset. Recent literature has strongly suggested that the unique toxins and chemicals veterans are exposed to could be at the root of their disease. A 2017 retrospective exposure assessment in veterans with ALS reported potentially higher exposure to hydrocarbon solvents, chlorinated solvents, and pesticides. Other substances to consider include DEET insect repellent, oil well combustion products, diesel exhaust, depleted uranium for armor/munitions, and biowarfare agents such as acid aerosols, hydrazines, mustard agents, sarin, and pyridostigmine bromide. Some have proposed that veterans from the Air Force specifically may be more predisposed than others due to aircraft exhaust exposure. However, it is important to note that further studies found no significant difference between branches. Therefore, the neurotoxic substances may originate from a common source present throughout all branches of the military. In addition to exposure to environmental agents, ongoing studies suggest that common military behaviors such as extreme physical exertion, traumatic brain injuries, concussions, smoking, and alcohol consumption may also play a role in the increased prevalence of ALS in veterans. Although further research is needed to identify the specifics of these environmental and social factors, the connection between military service, regardless of branch or time served, and ALS is well established.

What resources are available for U.S. military veterans diagnosed with ALS? In September 2008, ALS was officially recognized as a service-connected disease by the Department of Veterans Affairs (VA). This designation opened up a world of benefits for military veterans diagnosed with ALS who have served at least 90 continuous days on active duty. These benefits can include disability compensation, housing grants, handicap-friendly automobile grants, power wheelchairs, full coverage of FDA-approved medications, home-based primary care, and more. The ALS Association’s website offers a wealth of information regarding benefits available to veterans. Additional veteran service organizations that primary care physicians can refer their patients to include Paralyzed Veterans of America, the American Legion, and Disabled American Veterans. Although the connection between military service and ALS has been recognized by the VA since 2008, little has been done to reduce the risk. We urge both patients and their caretakers, including physicians, to partake in advocacy for better protection against modifiable risk factors in military service. Medical professionals, patients, and their loved ones have the right to fight for better health outcomes for military veterans, and raising awareness is the first step.

Currently, there is a lack of a reliable biomarker to quantify neurotoxicant exposure and its correlation with the progression of ALS. Researchers are urgently searching for one, as it would allow for stronger correlations. Unfortunately, this will take time. For now, we call for greater protective measures for current and future veterans. Additionally, we must continue educating both patients and providers about the associations of ALS, which are alarmingly present in the U.S. veteran population, leading to faster diagnoses. When the average life expectancy after diagnosis is only two to five years, even one day without answers can feel like a lifetime lost to patients and their loved ones. With faster recognition and diagnosis, interdisciplinary teams can be involved early to connect patients with the VA system and other supportive resources, ultimately reducing the social and economic consequences of ALS for U.S. veterans and their families.

Sumeet Dhillon and Jennifer Cesolini are medical students.