Presentation
Right sensorineural hearing loss since birth.
Patient Data
Hypoplasia of the cisternal and intracanalicular fibers of the right vestibulocochlear nerve.
Normal vestibule and cochlea on both sides.
Normal left vestibulocochlear nerve and facial nerves on both sides.
Average caliber of the internal auditory canals on both sides.
Case Discussion
This is a rare case of sensorineural hearing loss caused by isolated vestibulocochlear hypoplasia in the absence of internal auditory canal stenosis/atresia or inner ear abnormalities which are common associations.
Absence or reduction in the caliber of the cochlear nerve (deficiency) has been described in association with congenital sensorineural hearing loss (SNHL). It's usually associated with internal auditory canal stenosis (IAC) and inner ear abnormalities.
Assessment of internal auditory canals and the vestibulocochlear nerve is critical before cochlear implantations as they are considered contraindications. In such cases, an auditory brainstem implant (ABI) may be suggested.
This case is courtesy of Dr Mostafa El Khashab, MD of radiodiagnosis.