3-DIMENSIONAL IMAGING FOR PRESENTATION OF THE CAUSATIVE VESSELS IN PATIENTS WITH HEMIFACIAL SPASM AND TRIGEMINAL NEURALGIA

BACKGROUND In patients with hemifacial spasm and trigeminal neuralgia, preoperative detection of the relationship between the blood vessels and the cranial nerves involved is essential. METHODS We studied the c ausative vessels in 20 patients with hemifacial spasm and six patients with trigeminal neuralgia by means of magnetic resonance (MR) imaging with spoiled gradient recalled acquisition in the steady state (SPGR) , MR angiography, and three-dimensional (3-D) imaging reconstructed fr om the data of SPGR MR imaging by the surface rendering method at a wo rkstation. RESULTS In all patients, the preoperative SPGR MR images de monstrated that the causative vessels compressed or were in contact wi th the root exit or root entry zone (REZ) of the facial or trigeminal nerve. These causative vessels were identified by inspection of the MR angiographic and 3-D images. The 3-D images provided clear informatio n as to the anatomic relationship between the causative vessels and th e REZ of these nerves. These findings were corroborated by the intraop erative findings. The symptoms were completely relieved after surgery in 18 of the patients with hemifacial spasm and in all six patients wi th trigeminal neuralgia. In all patients, sufficient decompression was depicted on the postoperative SPGR MR images at the causative vessels and the REZ of the nerve. CONCLUSION SPGR MR images, MR angiography, and 3-D images are useful for the identification of the causative vess els in patients with hemifacial spasm or trigeminal neuralgia. The 3-D images are particularly useful for the simulation planning of the ope rative procedure. (C) 1997 by Elsevier Science Inc.