Endovascular microcatheter provocation test for the diagnosis of glossopharyngeal neuralgia.

OBJECTIVE: Glossopharyngeal neuralgia (GN) is a rare disease often clinically misdiagnosed as trigeminal neuralgia. An endovascular provocative test has been applied to assist in making the diagnosis of GN caused by vascular compression. We similarly used endovascular provocative techniques to identify the causative vessel and to evaluate the indication for microvascular decompression (MVD) in two patients.

METHODS: Two patients had severe retroauricular and pharyngeal pain that could not be controlled by medical therapy. Magnetic resonance imaging and magnetic resonance angiography showed a high-riding right posterior inferior cerebellar artery (PICA). We decided to apply the endovascular provocation test to prove the assumed GN and identify potential indications for MVD.

RESULT: A loop of the PICA appeared to compress the glossopharyngeal nerve in the first patient. In this patient, a microcatheter was inserted into the right PICA, decreasing the GN. The patient underwent MVD, resulting in complete pain relief. In the second patient, a microcatheter was inserted into the right PICA, and an attack of typical GN occurred, with pain in the posterior region of the tongue, tonsils, oropharynx, and larynx. The patient's severe pain was clearly different from this typical GN caused by the microcatheter provocation test, and MVD was not performed.

CONCLUSION: The diagnosis of GN is sometimes complex. The endovascular provocative technique may allow identification of GN caused by vascular compression.