Presentation
Sensorineural hearing loss. Preoperative evaluation.
Patient Data
Anomalous subarcuate canal courses through the superior and lateral semicircular canals' arches to join the mastoid segment of the facial canal.
Case Discussion
The typical subarcuate canal is not well seen after coursing between the arch of the superior semicircular canal and terminates in the region of the mastoid antrum. The subarcuate canal in this case anomalously courses inferiorly through the lateral semicircular canal's arch to join the mastoid segment of the facial canal. A few similar cases have been reported previously 1,2.
The subarcuate artery runs through the subarcuate canal and forms anastomoses with the internal auditory artery, superficial petrosal artery, and the stylomastoid artery.