Duplicate internal auditory canals with facial and vestibulocochlear nerve dysfunction

• Published in: Journal of laryngology and otology Vol. 126; no. 1; pp. 66 - 71
• Main Authors: Kew, T Y, Abdullah, A
• Format: Journal Article
• Language: English
• Published: Cambridge, UK Cambridge University Press 01.01.2012
• Subjects: Adult; Aplasia; Betahistine - therapeutic use; Biological and medical sciences; Children; Computed tomography; Constriction, Pathologic; Ear canal; Ear, auditive nerve, cochleovestibular tract, facial nerve: diseases, semeiology; Ear, Inner - abnormalities; Ear, Inner - diagnostic imaging; Facial nerve; Facial Nerve - abnormalities; Facial Nerve - physiopathology; Facial Paralysis - physiopathology; Hearing loss; Hearing Loss, Sensorineural; Hearing Loss, Unilateral; Humans; Hypoplasia; Hypotheses; Magnetic resonance imaging; Magnetic Resonance Imaging - methods; Male; Medical sciences; Nerves; Nervous system (semeiology, syndromes); Nervous system as a whole; Neurology; Non tumoral diseases; Otorhinolaryngology. Stomatology; Paralysis; Radiography; Tinnitus; Tinnitus - drug therapy; Tomography; Vestibulocochlear nerve; Vestibulocochlear Nerve - abnormalities; Facial Paralysis; Abnormalities, Temporal Bone; Tinnitus; Hearing Loss, Sensorineural; Sensorineural; Nervous system diseases; Temporal bone; Motor system disorder; Abnormalities; Facial paralysis; Auditory disorder; Facial nerve; ENT; Hearing loss; Cranial nerve disease; Dysfunction; ENT disease; Neurological disorder; Internal auditory meatus
• ISSN: 0022-2151; 1748-5460
• DOI: 10.1017/S0022215111002258

We report an extremely rare case of duplication of the internal auditory canal associated with dysfunction of both the facial and vestibulocochlear nerves. We also review the literature regarding the integrity of the facial and vestibulocochlear nerves in such cases. A 34-year-old man presented with unilateral, right-sided, sensorineural hearing loss and facial nerve palsy since childhood. Facial nerve function was observed to be House-Brackmann grade III. Computed tomography and magnetic resonance imaging demonstrated ipsilateral duplicate, vacant internal auditory canals. Based on the clinical presentation, we interpreted these radiological findings as aplasia of the vestibulocochlear nerve and severe hypoplasia of the facial nerve. To our best knowledge, this is the first report of vestibulocochlear nerve aplasia and severe facial nerve hypoplasia in a case of ipsilateral duplication of the internal auditory canal. High resolution gradient echo magnetic resonance imaging sequences are advocated for assessment of neural integrity in patients with an abnormal internal auditory canal and facial and/or vestibulocochlear nerve dysfunction.