Treatment of trigeminal neuralgia and other facial pains by retrogasserian injection of glycerol.

Håkanson's treatment of trigeminal neuralgia by injecting 0.2 to 0.4 ml of glycerol into the cerebrospinal fluid in Meckel's cave was carried out in 27 patients with trigeminal neuralgia, 3 with atypical facial neuralgia, and 1 with post-traumatic facial neuralgia. Minor modifications of his technique are described based on our finding of a greater pain and sensory loss upon injection than he noted. We present evidence that glycerol is more toxic than its cryoprotectant effect would intimate and that it selectively eliminates those components of the compound action potential in the trigeminal rootlets customarily associated with pain. We conclude that the method is probably going to be an improvement over radiofrequency heating for the treatment of trigeminal neuralgia in many situations.