Cranial root injury in glossopharyngeal neuralgia: electron microscopic observations. Case report

Optical and electron microscopic examinations were made of a biopsy sample of the ninth and 10th cranial nerves obtained during posterior fossa surgery for the relief of pain in a patient suffering from glossopharyngeal neuralgia (GN). Pathological findings, which were restricted to a small fraction of fascicles in the nerves, included large patches of demyelinated axons in close membrane-to-membrane apposition to one another and zones of less severe myelin damage (dysmyelination). These observations, in the light of similar morphological changes observed in biopsy samples excised from patients with trigeminal neuralgia, and new information on the pathophysiological characteristics of injured peripheral nerve axons, can account for much of the symptomatology of GN.