Use of endotracheal tube electrodes in treating glossopharyngeal neuralgia: technical note

This paper describes the use of endotracheal tube surface electrodes to help delineate the sensory and motor vagal rootlets which may be sacrificed during the surgical treatment of glossopharyngeal neuralgia.

Three patients with glossopharyngeal neuralgia were studied. All patients had their procedure under general anesthesia and a nerve integrity monitor electromyography endotracheal tube (Medtronic Xomed, Jacksonville, Fla., USA) was inserted under direct vision by the anesthesiologist. A bipolar stimulating electrode identified which, if any, of the upper rootlets of the vagus nerve caused a motor contraction near the vocal cords (i.e. motor branch) and which did not cause contractions (i.e. sensory branch). Sectioning of the glossopharyngeal and any purely sensory rootlets of the vagus nerve was subsequently performed.

All patients had immediate and long-lasting relief of their glossopharyngeal neuralgia. In all 3 patients, use of the bipolar stimulating electrode on the lower vagal rootlets induced a recordable muscle action potential in the region of the vocal cords with low current (<0.2 mA). There were no complications consequent to placement of the nerve integrity monitor endotracheal tube.

Due to the ease of use and reduced trauma, compared to needle electrodes, we would advocate endotracheal tube surface electrode monitoring in all patients undergoing surgical treatment of their glossopharyngeal neuralgia or any intracranial procedure where the integrity of the vagal nerve is in jeopardy.