Neurological Conditions
Amyotrophic Lateral Sclerosis (ALS)
An introduction to ALS and an explanation of why no county-level ALS measure is presented on MedEquity.
Beginner explanation
Amyotrophic lateral sclerosis (ALS) is a progressive disease of the nervous system that attacks motor neurons — the nerve cells in the brain and spinal cord that send messages to the muscles people control, such as those in the arms and legs.[1, 2]
As motor neurons die over time, muscles weaken, lose mass and can no longer be controlled. At first, people may notice mild problems such as trouble walking, running or writing, or speech problems. Eventually, people lose strength and the ability to move, and breathing becomes difficult when chest muscles weaken.[1, 2]
There is no cure. Medicines can relieve symptoms and, in some cases, slow progression or help people live somewhat longer.[1, 3]
Key definitions
- Motor neuron
- A nerve cell in the brain or spinal cord that controls muscle movement.
- Sporadic ALS
- ALS in a person with no apparent family history of the disease; most people with ALS have this form.
- Familial ALS
- ALS that runs in families; estimated at about 5% to 10% of cases.
- Frontotemporal dementia (FTD)
- A progressive brain disorder affecting personality, behavior and language that develops in some people with ALS.
- Dysarthria and dysphagia
- Slurred speech, and difficulty chewing or swallowing.
Sources[2]
Condition characteristics
Early symptoms can be subtle and overlooked: muscle twitching, cramping, stiffness or weakness. Weakness often starts in one part of the body, such as an arm or hand, and slowly spreads. Over time people may have:[2, 3]
- Difficulty lifting, climbing stairs and walking
- Slurred speech and voice changes
- Difficulty swallowing, choking easily or drooling
- Weight loss and loss of muscle mass
- Difficulty breathing
Source[3]
ALS does not affect the senses, and most people continue to think normally, although about 20% of people with ALS also develop frontotemporal dementia. Most people with ALS die from respiratory failure, often within 2 to 10 years of the first symptoms, but progression varies widely.[2, 3]
Risk factors
No one knows what causes most ALS. It usually strikes at random, but can run in families; about 1 in 10 cases is due to an inherited genetic variant.[1, 3]
MedlinePlus lists these risk factors: having a family member with a hereditary form of ALS, older age, male sex, exposure to toxins, strenuous activity, traumatic brain injury and military service — the reasons for the military link are unclear.[3]
Sporadic ALS usually first appears in a person’s late fifties or early sixties, while familial ALS typically appears in the late forties or early fifties.[2]
Prevention and public health context
There is no known way to prevent ALS. Care focuses on maintaining function and quality of life: physical therapy and rehabilitation, braces or wheelchairs, nutrition support (because the disease raises energy needs while swallowing becomes harder), and breathing support, from non-invasive machines to ventilation.[3]
CDC’s National ALS Registry collects information from people living with ALS to support research into who gets ALS and why, and connects patients with clinical trials.[4]
Texas data context
MedEquity does not present a county-level ALS measure. ALS is rare — about 5,000 people in the United States are diagnosed each year — so county counts would be very small and unstable, and no verified, publicly releasable county dataset has been identified.[2]
CDC’s National ALS Registry dashboard reports national figures, such as projected U.S. prevalence of ALS among adults.[4]
Related measures on the Explore map
No verified county-level measure exists for this topic, so no map link is offered.
Advanced material (optional)
Several genes are linked to familial ALS. Mutations in the C9orf72 gene account for 30% to 40% of familial ALS in the United States and Europe; worldwide, SOD1 mutations cause 15% to 20% of familial cases, and TARDBP and FUS each account for about 5%. Only a small share of all ALS cases has a known genetic cause.[2]
A rare form called ALS-parkinsonism-dementia complex occurs among the Chamorro people of Guam and people from the Kii Peninsula of Japan, where it can be about 100 times more frequent than ALS elsewhere.[2]
References
- Amyotrophic Lateral Sclerosis. MedlinePlus, U.S. National Library of Medicine. https://medlineplus.gov/amyotrophiclateralsclerosis.html (accessed 2026-10-18).
- Amyotrophic lateral sclerosis — MedlinePlus Genetics. U.S. National Library of Medicine. https://medlineplus.gov/genetics/condition/amyotrophic-lateral-sclerosis/ (accessed 2026-10-18).
- Amyotrophic lateral sclerosis (ALS) — Medical Encyclopedia. MedlinePlus, U.S. National Library of Medicine. https://medlineplus.gov/ency/article/000688.htm (accessed 2026-10-18).
- National Amyotrophic Lateral Sclerosis (ALS) Registry. Centers for Disease Control and Prevention / ATSDR. https://www.cdc.gov/als/ (accessed 2026-10-18).