Is progressive muscular atrophy the same as ALS (amyotrophic lateral sclerosis)?

Progressive muscular atrophy is not necessarily amyotrophic lateral sclerosis (ALS). ALS is a syndrome known as amyotrophic lateral sclerosis, primarily caused by damage to both upper and lower motor neurons, leading to progressive weakness and atrophy of muscles in the limbs, trunk, chest, and abdomen. However, there are numerous potential causes of progressive muscular atrophy; although it is one of the clinical manifestations of ALS, its presence does not definitively indicate ALS.