Progressive muscular atrophy

Progressive muscular atrophy (PMA), also called Duchenne–Aran disease and Duchenne–Aran muscular atrophy, is a disorder characterized by the degeneration of lower motor neurons, resulting in generalized, progressive loss of muscle function.

PMA is classified among motor neuron diseases (MND) and it sporadically appears during adulthood. It is speculated that about 2.5%-11% of adult onset MND is PMA, making it less common than ALS.

PMA affects only the lower motor neurons, in contrast to amyotrophic lateral sclerosis (ALS), the most common MND, which affects both the upper and lower motor neurons, or primary lateral sclerosis, another MND, which affects only the upper motor neurons.

The history of PMA involved determining if it was a separate disease from ALS or if it was just the earlier stages of ALS. Eventually, scientists concluded that PMA was its own disease under the same category as ALS. The signs and symptoms of PMA are similar to ALS, but are located in a different region of the body. Additionally, the diagnosis can be more complex due to the nature of PMA and ALS. The prognosis of PMA can be longer than ALS because it affects less of the motor neurons. The options for treatment are small and are still being explored, from stem cell treatment to simple physical therapy. Although there is no cure, some treatments, such as physical therapy and certain medications, can slow its progression.