Electromyography findings in radiation-induced unilateral tongue immobility.

BACKGROUND

We used electromyography to characterize hypoglossal nerve function among radiation-treated head and neck cancer survivors with later onset unilateral tongue immobility.

METHODS

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.

RESULTS

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.

DISCUSSION: These findings highlight how disparate mechanisms may underlie similar clinical presentations of radiation-induced neuromuscular dysfunction.