An unusual cause for trigeminal neuralgia: contralateral meningioma of the posterior fossa.

Twenty cases of facial neuralgia associated with tumors of the contralateral posterior fossa were collected from the world literature. Only four of these conform to the description of typical trigeminal neuralgia. We report on a fifth such case with a critical review of the literature. Subtotal excision of the tumor improves the pain and may convert a carbamazepine-resistant neuralgia into a responsive one. Total excision is often followed by a cure. Faced with such a case, the tumor should always be excised first, as this usually cures the neuralgia. Surgical treatment of the neuralgia in the presence of the tumor may be followed by disastrous results. An alternative hypothesis to the pathogenesis of the contralateral neuralgia is presented.