ALS was first identified as a distinct disease in the 1860s, making it over 150 years old as a medical diagnosis. French neurologist Jean-Martin Charcot and his colleague Joffroy conducted the foundational studies between 1865 and 1869, though the disease itself certainly existed long before anyone had the tools to describe it. What’s changed dramatically since then is how we understand it, diagnose it, and talk about it.
Charcot’s Discovery in the 1860s
Between 1865 and 1869, Charcot and Joffroy studied patients at the Salpêtrière Hospital in Paris and identified something crucial: damage to different parts of the spinal cord produced different patterns of paralysis. Lesions in the lateral columns caused progressive paralysis with stiff, contracted muscles but no wasting. Lesions in the anterior horn caused paralysis with muscle wasting but without that stiffness. ALS involves both types of damage happening simultaneously, which is what makes the disease so devastating and what made it recognizable as its own condition.
Charcot didn’t actually coin the term “amyotrophic lateral sclerosis” until 1874, when his lectures were compiled into a collected works titled “Oeuvres Completes.” The name itself is a clinical description: “amyotrophic” refers to muscle wasting, “lateral” points to the affected area of the spinal cord, and “sclerosis” describes the scarring found there. In much of the world, ALS is still called Charcot’s disease in his honor.
Lou Gehrig and the American Name
For decades after Charcot’s work, ALS remained a diagnosis known mainly to neurologists. That changed in 1939 when Lou Gehrig, one of baseball’s most famous players, was diagnosed with the disease on his 36th birthday during a visit to the Mayo Clinic on June 19. Shortly after, he retired from the New York Yankees. The team honored him on July 4, 1939, at Yankee Stadium in what became one of sports’ most iconic moments.
Gehrig died on June 2, 1941, and his very public decline brought ALS into the American consciousness in a way no medical paper ever had. For many years afterward, ALS was commonly known as “Lou Gehrig’s disease” in the United States, a name that persists today. The association with a beloved athlete gave the disease a human face and a level of public awareness it had lacked for the previous 70 years.
How Diagnosis Has Evolved
For most of the 20th century, diagnosing ALS was largely a matter of clinical judgment. There is no single test for the disease. Doctors had to observe the pattern of symptoms and rule out other conditions, which meant diagnoses were inconsistent and often delayed.
Formal diagnostic criteria didn’t arrive until 1994, when the El Escorial criteria established standardized guidelines for the first time. These were revised in 2000 (sometimes called the Arlie House criteria), updated again in 2008 with new electrical nerve testing standards (the Awaji criteria), and most recently refined with the Gold Coast criteria in 2021. Each revision has generally aimed to make earlier diagnosis possible, since the original El Escorial criteria were widely considered too strict, potentially delaying treatment for patients who clearly had the disease but didn’t yet meet every formal requirement.
Genetic Breakthroughs in the 1990s
For over a century after Charcot’s discovery, the underlying cause of ALS remained a mystery. The first major genetic breakthrough came in 1993, when researchers identified mutations in a gene called SOD1 as a cause of inherited ALS. This was the first proven genetic link to the disease and opened up an entirely new avenue of research. Since then, scientists have identified dozens of other genes associated with ALS, though the majority of cases (around 90%) are still classified as sporadic, meaning they occur without a clear family history.
The SOD1 discovery mattered beyond genetics. It allowed researchers to create animal models of the disease for the first time, which became essential for testing potential treatments. Nearly every ALS therapy developed in the following decades traces some part of its research lineage back to that 1993 finding.
The First Treatments
For 126 years after Charcot described the disease, there was no medication that could slow its progression. That changed on December 12, 1995, when the FDA approved the first treatment specifically for ALS. The drug extends survival and delays the need for a tracheostomy, though its effect is modest, typically adding a few months of life. It remained the only approved option for over two decades.
Additional therapies have since been approved, but ALS remains one of the most difficult diseases to treat. Average survival after diagnosis is still two to five years for most patients, a timeline that has not shifted as dramatically as many had hoped given the pace of genetic discoveries.
ALS Today
The CDC estimates that close to 33,000 people in the United States were living with ALS in 2022, and that number is projected to rise by more than 10% to over 36,000 cases by 2030. The increase is driven partly by an aging population and partly by improvements in diagnosis and data collection.
The disease that Charcot first described in a Parisian hospital over 150 years ago is fundamentally the same condition patients face today. What has changed is visibility. The 2014 Ice Bucket Challenge raised over $115 million for ALS research and brought the disease to a level of public awareness that rivaled Lou Gehrig’s diagnosis. The science has advanced enormously since the 1860s, from identifying the first gene to developing the first treatments to refining diagnostic criteria four times over. But the core challenge remains: ALS is still a disease with no cure, and the gap between understanding it and stopping it is one of neurology’s most persistent problems.