Evaluation of electrical impedance myography as a noninvasive musculoskeletal biomarker in infantile- and late-onset Pompe disease.

Abstract

Patients with infantile-onset Pompe disease (IOPD) and late-onset Pompe disease (LOPD) experience progressive motor deficits. Current methods for assessing muscle health, such as motor tasks or magnetic resonance imaging (MRI), are limited in young or severely affected individuals. This study evaluated electrical impedance myography (EIM) as a noninvasive biomarker of muscle health in PD. Sixty-four participants (11 with IOPD, 27 with LOPD, and 26 healthy controls) were assessed. EIM phase and reactance values were obtained from bilateral limb muscles. Twenty participants with PD underwent lower limb musculoskeletal MRI. Participants completed the Perceived Stress Scale-10 and Patient-Reported Outcomes Measurement Information System questionnaires. Motor performance was evaluated via balance tests, the 9-Hole Peg Test, grip strength, the 2-Minute Walk Test, and the 4-Meter Walk Test. Participants with PD reported greater impairment in pain intensity, mobility, physical stress experience, and physical function, and performed worse on motor tasks than healthy controls (all P < .05). EIM phase at 100 and 211 kHz was reduced in participants with PD, particularly in those with IOPD and in pediatric participants with PD compared with healthy controls. Lower phase correlated with higher MRI fat fraction and poorer motor performance. With additional longitudinal investigation, EIM may represent a functionally relevant, noninvasive tool to evaluate disease severity in individuals with PD.