How long has ALS been known?

ALS was first described in 1869 by the French neurologist Jean-Martin Charcot at the Hôpital de la Salpêtrière in Paris. He named the disease “amyotrophic lateral sclerosis.” As early as 1850, the French neurologist François Aran discovered progressive muscular atrophy (PMA). The initial assumption was that PMA was a muscle disease. Shortly thereafter, in 1852, the neurologist Cruveilhier determined that PMA is a disease of the motor nervous system. It was later proven that PMA is a specific variant of ALS. Thus, ALS in the broader sense was first characterized by Aran as early as 1850. The name, which remains in use today, was coined 19 years later by Charcot.

Overall, the history of ALS dates back to the clinical descriptions of various disease phenotypes and their anatomical basis. Among the most important forms are the one mentioned above, which is characterized by involvement of only the second-order motor neurons, and primary lateral sclerosis (PLS), which affects only the first-order motor neurons.

Different patterns of progression were also recognized early on. Examples include progressive bulbar palsy (PBP), flail arm syndrome (FAS), the thoracic variant of ALS, and flail leg syndrome (FLS). The respective motor phenotype depends largely on the initial location of motor neuron degeneration and its subsequent spread along the anatomical structures of the first and/or second motor neuron.