The results of the surgical treatment of trigeminal neuralgia are brilliant and extremely gratifying to patient and surgeon alike. Section of the sensory root of the fifth cranial nerve offers immediate and lasting relief from an excruciating pain which defies description. Among an appreciable number of patients suffering from a true major neuralgia involving the trigeminal nerve there is a small number complaining of pain in the face which must be differentiated from typical trigeminal neuralgia. These patients offer a real differential diagnostic problem because surgical measures directed toward the fifth cranial nerve usually offer no relief. The history given is that of a deeply situated, dull ache occurring in one or more of the areas supplied by the divisions of the trigeminal nerve. It may be more or less continuous and attended by exacerbations, and it may spread from one divisional area to another. The important point to be