Microvascular Decompression for Glossopharyngeal Neuralgia: Surgical Approaches Depending on the Offending Artery

Abstract

Glossopharyngeal neuralgia (GPN) is one of several microvascular compression syndromes. The neuralgia is characterized by unilateral, paroxysmal, lancinating pain in the oropharynx or tonsillar fossa, spreading to the external auditory canal through the eustachian tube. It is often caused by activities such as talking, eating, swallowing, and coughing. “Typical” GPN is easily diagnosed when a patient presents the aforementioned symptoms in combination with radiological features, ascertained by magnetic resonance imaging (MRI)/magnetic resonance angiography (MRA), such as posterior inferior cerebellar artery (PICA) with a high origin that forms an upward loop (Fig. 13.1). However, unless these typical features of PICA are evident on MRI/MRA, the diagnosis and efficacy of microvascular decompression (MVD) remain uncertain. In such cases, the characteristics of the pain, e.g., location within the distribution of cranial nerve (CN) IX, paroxysmal, and association with swallowing, aid diagnosis. Carbamazepine therapy is effective and can be used for a diagnostic trial. Furthermore, the application of 10 % cocaine or lidocaine to the pharynx, a test block, relieves the pain of GPN. With the confirmation of these characteristics, the diagnosis of GPN becomes more reliable and successful outcomes of MVD can be expected.