Dados do Trabalho

Título

Post-radiotherapy unilateral hypoglossal neuropathy: a case report

RESUMO

A 54-year-old man had development of involuntary movements of his tongue started one month before the first neurologic evaluation. Those movements were intermittent occurring around ten times a day.
One year prior, he presented an airway obstruction that led him to tracheostomy and the diagnosis of invasive squamous cell carcinoma at the right amygdala. He underwent 35 sessions of radiotherapy and was considered cured. His medical history was also relevant for systemic hypertension, chronic kidney disease (due to systemic hypertension) and hepatitis C. He was a former smoker, quitting the habit about 30 years prior.
At neurologic examination, tongue fasciculation was observed along with right sided deviation at protrusion. A CT brain scan excluded cancer recurrence.
An electroneuromyography was performed and disclosed chronic axonal involvement of the hypoglossal nerve, with the presence of fasciculation, probably related to actinic neuropathy.
Low-dose carbamazepine treatment was started and by the dose of 200mg twice a day, the patient had a complete improvement of the fasciculations.

Radiation-induced lower cranial nerve neuropathy is a rare complication of radiotherapy. It usually starts around five years after radiation and bilateral involvement has been described. The most affected nerve is the hypoglossal, due to its long and tortuous course from the brainstem to the tongue. The most important risk factor for lower cranial nerve neuropathy is a large total radiation dose (more than 70Gy). No treatment has already been proved as effective, but there are some case reports on positive outcomes with high-dose steroids. There is also some data about the use of carbamazepine as a membrane-stabilizing drug that may reduce nerve hyperexcitability.

Our case reports an earlier lower cranial nerve neuropathy due to radiotherapy with a very good outcome with low dose of carbamazepine.
Cancer patients are surviving much longer nowadays, and it is extremely important to diagnose the treatment-related complications, firstly because of their impact on the patients’ quality of life and secondly they may shorten patients life spam.