RT Journal Article SR Electronic T1 CT and MR Findings of Michel Anomaly: Inner Ear Aplasia JF American Journal of Neuroradiology JO Am. J. Neuroradiol. FD American Society of Neuroradiology SP 281 OP 284 VO 20 IS 2 A1 Kathlyn Marsot-Dupuch A1 Alessandro Dominguez-Brito A1 Karim Ghasli A1 Claude-Henri Chouard YR 1999 UL http://www.ajnr.org/content/20/2/281.abstract AB Summary: In 1863, Michel described a condition characterized by a total absence of differentiated inner ear structures associated with other skull base anomalies, including an abnormal course of the facial nerve and jugular veins. Michel aplasia clearly differs from Michel dysplasia, in which arrest of embryologic development occurs later. Recently, the role of otic capsule formation on mesenchymal differentiation was reported as well as the impact of the genetic deletion of the homeobox gene on the development of the ear, cranial nerves, and hindbrain. We report two patients with a total absence of inner ear structures bilaterally, illustrating the characteristic appearance of Michel aplasia and associated skull base anomalies.