STUDY OF 962 PATIENTS INDICATES PROGRESSIVE MUSCULAR ATROPHY IS A FORM OF ALS

Abstract

Background: Progressive muscular atrophy (PMA) is clinically characterized by signs of lower motor neuron dysfunction and may evolve into amyotrophic lateral sclerosis (ALS). Whether PMA is actually a form of ALS has important consequences clinically and for therapeutic trials. We compared the survival of patients with PMA or ALS to analyze the clinical features that influence survival in PMA. Methods: We reviewed the medical records of patients with PMA (n = 91) or ALS (n = 871) from our ALS Center and verified survival by telephoning the families or using the National Death Index. Results: In PMA, patients were more likely to be male ( p p = 0.007), and lived longer ( p = 0.01) than in ALS. Cox model analysis suggested that the risk of death increased with age at onset in both patient groups ( p Conclusion: Although patients with progressive muscular atrophy (PMA) tended to live longer than those with amyotrophic lateral sclerosis (ALS), shorter survival in PMA is associated with the same risk factors that predict poor survival in ALS. Additionally, PMA is relentlessly progressive, and UMN involvement can occur, as also reported in imaging and postmortem studies. For these reasons, PMA should be considered a form of ALS.