Evidence that the site of action of glycerol in relieving tic douloureux is its actual site of application.

Axonal transport of 3H labeled glycerol in the rat trigeminal nerve was investigated as well as the effects of pure glycerol on the infraorbital nerve (IN). 3H activity in the Gasserian Ganglion (GG) was less than 0.1% of that in the nerve stump at the application site. IN showed destructive changes at the injection site restricted mainly to the periphery of the nerve bundles. It was concluded that the site of action of glycerol in relieving trigeminal pain is its site of application irrespective whether applied as a peripheral injection or injected into the cistern of GG.