June 1988

Functional RecoveryA Major Risk Factor for the Development of Postpoliomyelitis Muscular Atrophy

Author Affiliations

From the Department of Neurology, University of Southern California School of Medicine, Los Angeles (Drs Klingman and Chui), and the Research and Training Center on Aging (Drs Chui and Corgiat) and the Department of Pathokinesiology (Dr Perry), Rancho Los Amigos Medical Center, Downey, Calif.

Arch Neurol. 1988;45(6):645-647. doi:10.1001/archneur.1988.00520300065020

• A retrospective study was undertaken to identify potential risk factors for the development of progressive postpoliomyelitis muscular atrophy (PPMA). Patients with PPMA (n = 57) were compared with patients with a history of poliomyelitis but without a history of progressive weakness (n = 49). Patients who later developed PPMA had histories of more widespread acute paralysis, but relatively greater functional recovery. They were less disabled, and reported higher recent activity levels. Seventy-nine percent of the total variance between the PPMA and control groups could be accounted for by recovery alone (ie, severity minus disability). Functional recovery is generally attributed to reinnervation of sarcomeres by collateral sprouting from surviving lower motor neurons. Since degree of recovery predicts the risk of developing PPMA, our findings suggest that enlarged motor units may carry an increased susceptibility for dysfunction and/or degeneration.