A successful treatment of hemifacial spasm due to anterior inferior cerebellar artery aneurysm in adolescent: a case report and literature review.

OBJECTIVE Hemifacial spasm (HFS) is usually caused by compression of the facial nerve at the root exit zone (REZ), and is extremely rare in adolescents and even rarer in aneurysm compression. CASE REPORT We describe symptomatic hemifacial spasm caused by a saccular aneurysm of the anterior inferior cerebellar artery (AICA) that was treated by clipping. A 17-year-old adolescent developed left hemifacial spasm that had gradually worsened over a period of 1 year before admission to our department. During the course of MVD (microvascular decompression), saccular aneurysm of AICA was accidentally found to compress the facial nerve. The cause of the facial spasm was considered to be compression of the left facial nerve by the aneurysm. Clipping the aneurysm was performed. The hemifacial spasm disappeared immediately. CONCLUSION Our report indicates that HFS caused by saccular aneurysm of AICA can be treated by clipping, and that aneurysms should be considered in the treatment of adolescent HFS, especially those difficult to identify on imaging examination.