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 diagnostic tools such as magnetic resonance imaging and fundus fluorescein angiography. The audiovestibular evaluation was done on the seventh day of admission (Session 1) into the emergency unit, whereas the second and third evaluations were done at 3-month (Session 2) and 8-month (Session 3) follow-ups after discharge, respectively. The audiovestibular test battery consisted of routine 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 audiovestibular evaluation may be essential in patients with SS. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.21513843.

Audiovestibular Dysfunction in Siblings with Charcot-Marie-Tooth Disease 4F: A Case Series.

BACKGROUND: Charcot-Marie-Tooth disease type 4F (CMT4F) is an autosomal recessive disorder with symptoms presenting in early adulthood. This clinical case series demonstrates atypical findings in cervical and ocular vestibular evoked myogenic potentials (VEMP) in siblings with CMT4F. PURPOSE: The aim of this study was to highlight the audiovestibular test findings in CMT4F. RESEARCH DESIGN: Case series study sample: 4 siblings, 3 of whom diagnosed with CMT4F. DATA COLLECTION AND ANALYSIS: Audiological test battery and electrophysiological tests comprising auditory brainstem response (ABR) and VEMP (both cervical and ocular) were performed in our patient population. RESULTS: Older siblings, in whom the hearing loss was present, manifested prolonged peak V latencies in ABR. Three out of four siblings with CMT4F showed prolongation of latencies on cervical and ocular VEMP. CONCLUSIONS: In many neurodegenerative conditions, prolongation of ABR peak latencies has often been reported in the literature. There have also been a few reports of prolonged VEMP peak latencies. This article reports prolongation of only VEMP peak latencies (in both cervical and ocular recordings). The youngest sibling had prolongation of VEMP latencies, with ABR peak latencies being normal. The assumption we put forth that CMT4F may affect the vestibular pathway first requires to be tested on a larger sample and by longitudinally studying the individuals with disease condition.