Fig. 9. Vascular compression of the trigeminal root by (A) the anterior inferior cerebellar artery (aica) and (B) the superior cerebellar artery (sca). (From Jannetta PJ, Zorub DS: Microvascular decompression for trigeminal neuralgia. In Buchheit WA, Truex RC (eds): Surgery of the Posterior Fossa. New York: Raven Press, 1979:146–147.)