NTCT-13VAGOGLOSSOPHARYNGEAL NEURALGIA PRESENTING AS FREQUENT SEIZURE-LIKE SPELLS IN A PATIENT WITH HEAD AND NECK CANCER TREATED WITH HIGH CUMULATIVE RADIATION DOSE

Abstract

A 62-year-old man presented with six months of numerous seizure-like events with a sequence of light-headedness, tonic extension of the right arm, loss of consciousness, urinary incontinence and convulsion. He had been diagnosed with laryngeal cancer five years prior, treated with definitive radiotherapy 72Gy in 36 fractions to the left glottis. He had local cancer recurrence three years later and was treated with additional surgeries including bilateral neck dissection and a pectoralis major myocutaneous flap. The following year he required extensive surgery for local disease recurrence and additional reconstruction. He underwent a second course of radiation of 60Gy in 30 fractions with concomitant cisplatin as a radiosensitizer. He achieved complete disease remission, with symptoms related to radiation dermatitis, dysphagia, and left ear pain. More than 20 seizure-like spells were documented, beginning fourteen months after final treatment. Many episodes were heralded by acute jaw and throat pain. Physical examination revealed an iatrogenic left hypoglossal nerve deficit, soft palate scarring, and post-radiation changes to the free flap of the neck and throat. During target events, his heart rate was 20 beats per minute and mean arterial pressure was 40-45 mmHg. EEG, brain MRI, and transthoracic echocardiogram were normal. This phenomenology of seizure-like activity led us to consider the rare entity of radiation-related vagoglossopharyngeal neuralgia, given the very high cumulative local radiation dose. We treated him accordingly with midodrine and fludrocortisone after an incomplete response to atropine. Gabapentin, carbamazepine, and aggressive analgesia provided partial relief of his pain attacks. He remained syncope-free for four months and elected hospice at the time of cancer recurrence. There have been rare reported cases of cancer treatment-related glossopharyngeal neuralgia with convulsive syncope. Prompt diagnosis is necessary because it is a treatable life-threatening condition that could be confused for seizure presentation.