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Dolichoectatic and Tortuous Vertebrobasillary Arterial System Causing Progressive Left-Sided Hearing Loss in a Patient with Previous Right-Sided Deafness

Giant dolichoectatic aneurysms in the vertebrobasilar system are rare. They usually manifest themselves when they compress the brainstem or cranial nerves, or when they are complicated by intraluminal thrombi or dissection. A 63-year-old man presented with a 6-month history of progressive left-sided hearing loss and tinnitus, in addition to having hearing loss in the right ear since childhood. In audiological assessment total hearing loss was present in the right ear, while a mild degree of sensorineural hearing loss was noted in the left ear, especially at high frequencies. Speech discrimination was lower than normal, which was inconsistent with the degree of measured hearing loss, suggesting retrocochlear pathology. The tone decay test was positive for the left ear. All these findings, including an auditory brainstem response test, suggested the existence of retrocochlear pathology on the left side. Temporal-cranial MRI and cerebral angiography revealed a dolichoectatic basillar artery aneurysm that was compressing brainstem and bilateral tortuous dolichoectatic vertebral arteries compressing the root entry zones of the 7-8 cranial nerves. No surgical or vascular interventional treatment was recommended because of the high risk of complication based on the location of the lesion. After 1 year of anti-aggregant and antihypertensive treatment, audiological tests revealed total hearing loss in the left ear. Anti-aggregant and antihypertensive treatment was continued. Hacettepe University, Faculty of Medicine, Department of Otorhinolaryngology-Head and Neck Surgery (H.A. fienkal, E. Turan), Department of Radiology (K.K. O¤uz), Department of Section of Audiology and Speech Pathology (S. Özkan)