Electrodiagnostic Findings in Patients With Poliomyelitis

Abstract

Electrodiagnostic studies of patients with poliomyelitis reveal evidence of axonal degeneration from loss of anterior horn cells early in the course of the disease, and, in more chronic phases, reinnervation with increased motor unit size. Neuromuscular junction abnormalities may persist for three or more decades after the initial infection. Electrodiagnostic study techniques do not appear to be able to separate stable from unstable postpolio patients. These techniques may be helpful, however, in evaluating changes in muscle activity in postpolio patients who have adapted movements over time to improve their levels of function and the effects of interventions, such as exercise, on the surviving motor units.