Electrical impedance myography in the evaluation of the tongue musculature in amyotrophic lateral sclerosis.

ABSTRACT

INTRODUCTION: Electrical impedance myography (EIM) quantifies muscle health and is used as a biomarker of muscle abnormalities in neurogenic and myopathic diseases. EIM has yet to be evaluated in the tongue musculature in patients with amyotrophic lateral sclerosis (ALS), who often show clinical bulbar signs. METHODS: The lingual musculature of 19 subjects with motor neuron disease and 21 normal participants was assessed using EIM, strength and endurance testing, and clinical assessment. RESULTS: Tongue musculature in the ALS group was characterized by significantly smaller phase (Ph) and greater resistance (R) when compared with the healthy cohort. Ph and tongue endurance were correlated in the ALS group. CONCLUSIONS: EIM of tongue musculature could distinguish those with ALS from healthy controls. The demonstrated relationship between tongue function and Ph supports further testing of EIM of the tongue as a potential biomarker in ALS.