The anterior inferior cerebellar artery (AICA): clinical and radiological significance.

It is well known that the anterior inferior cerebellar artery (AICA) is difficult to visualize radiologically. As the analysis of 50 clinical cases shows, although the main branches of the AICA at the level of the basilar artery can be analyzed angiographically, the peripheral course is only vaguely visible. We examined 26 brains (postmortem) after selective resin-injection and preparation under an operation-microscope. Our results: 1. There is a reciprocal relationship between the development of the AICA and the PICA. 2. We can draw no conclusions concerning the pattern of the AICA of one side to the pattern on the other side. 3. The size of the AICA at the level of the basilar artery gives an indirect indication of the peripheral course. 4. The AICA and the cranial nerves are in a constant relationship to each other. Consideration of these relationships can help in the interpretation of angiograms done before microsurgical operations in the area of the cerebello-pontine angle.