Paroxysmal facial neuralgia secondary to a posterior communicating artery aneurysm.

Paroxysmal facial neuralgia, typified by classical tic douloureux, may be secondary to intermittent compression of the trigeminal nerve by pulsating vascular structures. The critical area of compression, at least for producing true trigeminal neuralgia, is felt to be the dorsal root entry zone. One case of paroxysmal facial neuralgia, secondary to more distal compression of the trigeminal nerve by a large posterior communicating artery aneurysm, is reported here. The location of the compression may be important in producing the atypical characteristics of paroxysmal facial neuralgia that is not classical tic douloureux. The pain was relieved by clipping the aneurysm without excision or rupture of the sack.