Glossopharyngeal neuralgia in the context of a Chiari type I malformation.

A 34-year-old woman presented with disabling right-sided glossopharyngeal neuralgia. MRI revealed a Chiari I malformation with an asymmetric herniation of the right tonsil. Surgical inspection of the lower cranial nerves through a suboccipital approach showed no vascular compromise. The patient was pain free for three months before the same symptoms recurred. MRI showed a persisting crowding at the level of the foramen magnum. A second intervention with extension of the suboccipital craniectomy and resection of the right tonsil achieved definitive pain relief. To our knowledge this is the fourth report of a glossopharyngeal neuralgia caused by a Chiari I malformation. Recurrence of the pain after incomplete decompression of the posterior fossa underlines the importance of tonsillectomy in these patients.