Cervical and Ocular Vestibular Evoked Myogenic Potential Recovery in Susac Syndrome: A Case Report

Purpose: Susac syndrome (SS) is a rare autoimmune disorder that affects the brain and the retina and causes unilateral or bilateral sensorineural hearing loss. Although vestibular dysfunction is reported in SS, limited information is available underlying the vestibular pathophysiology.Method: The diagnosis of SS was established based on symptoms and diag-nostic tools such as magnetic resonance imaging and fundus fluorescein angi-ography. The audiovestibular evaluation was done on the seventh day of admis-sion (Session 1) into the emergency unit, whereas the second and third evalua-tions were done at 3-month (Session 2) and 8-month (Session 3) follow-ups after discharge, respectively. The audiovestibular test battery consisted of rou-tine audiological tests, auditory brainstem response, and vestibular evoked myogenic potentials (VEMPs; both cervical and ocular).Results: We found unilateral sensorineural hearing loss and absent cervical VEMPs(cVEMPs) when testing the left ear during Session 1. In the following sessions, the unilateral hearing loss did not recover; however, cVEMPs were present bilaterally. The ocular VEMPs showed an increase in amplitude during Sessions 2 and 3.Conclusions: SS can selectively disrupt auditory and vestibular structures. It may present with unique findings of audiovestibular tests. A detailed audio -vestibular evaluation may be essential in patients with SS.Supplemental Material: https://doi.org/10.23641/asha.21513843