Glossopharyngeal neuralgia.

Glossopharyngeal neuralgia is a distinctive syndrome, named by Wilfred Harris. Investigation must exclude multiple sclerosis, and local compression, especially by tumours which require treatment. Dandy deserves credit for first indicating vascular compression of cranial nerve roots as a cause of cranial neuralgias, and Jannetta for establishing neurovascular decompression. Vascular compression is a common and treatable cause but does not account for all previously designated idiopathic cases.