Parapontine epidermoid tumours presenting as trigeminal neuralgias: anatomical findings and operative results.

Four cases of medically intractable trigeminal neuralgia caused by parapontine epidermoid tumours are reported. All patients presented with typical trigeminal neuralgia and low-density area in the parapontine region on CT-scans. Neurologically in all cases slight hypaesthesia in various divisions of the trigeminal nerve without other neurological signs was revealed. Trigeminal pain was completely relieved after surgery in all patients. Facial sensory disturbances and pain occur in patients with parapontine epidermoid tumour as a result of direct tumourous compression (and hypothetically toxic effects on the nerve root from the tumourous contents).