Three-dimensional morphology of the superior cerebellar artery running in trigeminal neuralgia.

The superior cerebellar artery (SCA) is the most frequent offending vessel in trigeminal neuralgia. This study aims to elucidate the patterns of the SCA running in 34 patients with typical trigeminal neuralgia using three-dimensional computer graphics. The SCA which runs in the medial aspect of the trigeminal nerve compressed predominantly the root entry zone at the distal segment of the caudal loop. Meanwhile, the SCA which runs in the cranial or lateral aspect of the trigeminal nerve compressed predominantly the mid-third portion at the proximal segment of the caudal loop. The site of neurovascular compression differed depending on the shape of the initial segment of SCA. Transposition methods could not be performed in several patients with arch-shaped SCA. Three-dimensional computer graphics revealed different characteristics of the SCA running in trigeminal neuralgia depending on the site of neurovascular compression and shape of the SCA. These differences might affect procedures for microvascular decompression.