Sudden unilateral deafness due to a right vertebral artery dissection

Case report.

We present a 42-year-old woman without a known connective tissue disorder, who sought treatment at the emergency department because of sudden right-sided deafness, vertigo, and tendency to fall to the right. She also reported right-sided neck pain for 3 days.

Neurologic examination, performed 1 day after the onset of symptoms, revealed total deafness on the right side. There were no other abnormalities, including no nystagmus (also not present after use of Frenzel glasses) and no ataxia.

An MRI scan showed a small cerebellar infarction in the territory of the right posterior inferior cerebellar artery (PICA) on the T2-weighted image (figure, A). On the sagittal T1-weighted images, the distal part of the right vertebral artery was hyperintense, and no flow void was seen (not shown). A contrast-enhanced MR angiography showed a normal proximal right vertebral artery that showed irregularities and tapering in the high cervical portion. The distal portion of the right vertebral artery was occluded (figure, B and C).

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Figure. (A) MRI (T2-weighted) showing a small right-sided posterior inferior cerebellar artery (PICA) infarction. (B and C) Contrast-enhanced MR angiography showing a normal proximal right vertebral artery with irregularities and tapering in the high cervical portion.

The combination of image findings suggest vertebral dissection.

In this patient, sudden deafness, vertigo, and neck pain were caused by a spontaneous right vertebral artery dissection. The patient was treated with low molecular weight heparin, especially to prevent new neurologic signs and symptoms. During follow-up evaluation, the unilateral deafness persisted without any other sequelae.

The differential diagnosis of sudden deafness includes trauma, viral disease, syphilis, Lyme disease, vascular disease, HIV, ototoxic drugs, autoimmune inner ear disease, perilymph fistulae, Meniere disease, and acoustic neurinoma.1-3⇓⇓

The symptoms of sudden deafness combined with vertigo and neck pain suggested the diagnosis of a vertebral artery dissection.

Discussion.

Sudden deafness has been described in anterior inferior cerebellar artery (AICA) infarction. Lee et al. described the signs and symptoms of 12 patients with unilateral AICA infarction.1 Vertigo was the initial symptom in all patients, accompanied by a horizontal-rotatory nystagmus beating toward the healthy side. Sensorineural hearing loss was present in 11 patients. Unlike our patient, all 12 patients had gait and limb ataxia caused by involvement of the middle cerebellar peduncle or anterior inferior cerebellum.1

Another recent article described bilateral deafness in vertebral insufficiency caused by stenosis of the basilar artery. Vertigo was present, but no nystagmus was observed in this patient as well.4

Our patient had unilateral sudden deafness caused by a right vertebral dissection. In most patients, the internal auditory artery originates from the AICA, but in a few, it branches off the PICA. In our patient, most likely, small emboli originating from the dissection caused a small selective cerebellar and cochlear infarction, sparing the vestibular apparatus. This led to unilateral sensorineural hearing loss without nystagmus. In conclusion, for patients presenting with neck pain and sudden unilateral sensorineural deafness, with or without vertigo, a vertebral artery dissection should be considered and MR angiography performed.