Myokymia is a type of muscle contractions typically appearing as involuntarily muscle undulation or twisting. Though there are many causes, the most common subtype is ocular myokymia, which can be induced by stress, fatigue, or caffeine. Myokymia can also be seen associated with post-radiation plexopathies and rarely other nerve injuries. This presentation will explore two cases that highlight lingual myokymia along with video demonstrations.

Patient A is a 69-year-old male with a past medical history of squamous cell carcinoma of the left side of jaw and neck, now status post radiation therapy to those areas. He developed left arm pain, numbness, and weakness, with proximal muscles most affected approximately four to five years later. He also noted to have continuous, undulating tongue movements that started around the time of his left arm symptoms.

Patient B is a 63-year-old female with a past medical history of squamous cell carcinoma of the tongue base. She underwent lesion excision and numerous radiation treatments to the tongue. Approximately five years later, she developed atrophy, writhing movements, and weakness of the tongue, presenting to clinic initially for concern for bulbar-onset ALS. Two annual follow up visits showed no further motor decline or progression to other body regions.