Electromyography findings in radiation-induced unilateral tongue immobility.

Abstract

We used electromyography to characterize hypoglossal nerve function among radiation-treated head and neck cancer survivors with later onset unilateral tongue immobility. Patients with unilateral tongue immobility without evidence of recurrent cancer were seen at a tertiary academic institution between February and September 2021. All patients were at least 2 years post-treatment with radiation therapy for head and neck squamous cell carcinoma. Participants were under annual surveillance and displayed no evidence of operative injury to the hypoglossal nerve. The median symptom-free interval for the 10 patients included in this study was 13.2 years (range 2-25 years). Myokymia alone was present in 3 of 10 patients, fibrillation potentials alone were present in 3 of 10 patients, and 1 subject displayed both fibrillation and myokymia. Three out of 10 patients had normal hypoglossal nerve function. These findings highlight how disparate mechanisms may underlie similar clinical presentations of radiation-induced neuromuscular dysfunction.