[Progressive muscle atrophy. A rarely diagnosed variant of amyotrophic lateral sclerosis]

Progressive muscle atrophy (PMA) is a degenerative disease of the lower motor neuron. The course of the illness and the fatal prognosis correspond to those of amyotrophic lateral sclerosis (ALS). Neuropathologic and genetic findings support categorizing PMA within the spectrum of ALS, even though no clinical sign of a disorder of the upper motor neuron is demonstrable. The diagnosis of PMA is based on advanced extremity pareses and atrophies with a high progression rate. Respiratory insufficiency is determinative of the prognosis. Absent or late affection of bulbar functions is characteristic of the disease. Intraneuronal bunina bodies and ubiquitine-positive inclusions, which are established morphologic characteristics of ALS, are found post mortem. The treatment options of riluzol medication, respiratory therapy, and nutrition are analogous to those for typical ALS.