Trigeminal neuralgia caused by compression from arteries transfixing the nerve. Report of three cases.

The authors present three patients with trigeminal neuralgia due to compression by an artery that transfixed the sensory root of the fifth cranial nerve. These cases represented 0.8% of 384 patients with trigeminal neuralgia treated by microvascular decompression at the authors' clinic during the past 12 years. In the remaining 381 cases, the compressing vessels were successfully removed from the trigeminal nerve without much difficulty, for an initial cure rate of 94.3%. In the three cases reported, however, the compressing artery penetrating the nerve could not easily be maneuvered away from the nerve. In the first two cases, partial rhizotomy perpendicular to the axis of the nerve at the site of arterial transfixion made it possible to separate the artery from the nerve. However, these two patients developed postoperative facial sensory impairment. In the third case, rhizotomy was performed longitudinal to the axis of the nerve at the site of arterial transfixion, making it possible to reposition the artery peripherally beyond the root entry zone of the nerve without causing any postoperative sensory deficits of the face. No recurrent pain has developed in more than 2 1/2 years since surgery in any of these three cases. When performing microvascular decompression surgery on patients in whom the compressing artery penetrates the nerve, the technique used in our third patient is the procedure of choice.