Mechanisms of Morbid Hearing Loss Associated With Tumors of the Endolymphatic Sac in von Hippel-Lindau Disease
John A. Butman, MD, PhD; H. Jeffrey Kim, MD; Martin Baggenstos, MD; Joshua M. Ammerman, MD; James Dambrosia, PhD; Athos Patsalides, MD; Nicholas J. Patronas, MD; Edward H. Oldfield, MD; Russell R. Lonser, MD
Endolymphatic sac tumors (ELSTs) are associated with von Hippel-Lindau disease and cause irreversible sensorineural hearing loss (SNHL) and vestibulopathy. The underlying mechanisms of audiovestibular morbidity remain unclear, and optimal timing of treatment is not known.
To define the underlying audiovestibular pathophysiologic mechanisms associated with ELSTs.
Design, Setting, and Patients:
Prospective and serial evaluation of patients with von Hippel-Lindau disease and ELSTs at the National Institutes of Health between May 1990 and December 2006.
Main Outcome Measures:
Clinical findings and audiologic data were correlated with serial magnetic resonance imaging and computed tomographic imaging studies to determine the mechanisms underlying audiovestibular dysfunction.
Thirty-five patients with von Hippel-Lindau disease and ELSTs in 38 ears (3 bilateral ELSTs) were identified. Tumor invasion of the otic capsule was associated with larger tumors (P = .01) and occurred in 7 ears (18%) causing SNHL (100%). No evidence of otic capsule invasion was present in the remaining 31 ears (82%). Sensorineural hearing loss developed in 27 of these 31 ears (87%) either suddenly (14 ears [52%]) or gradually (13 ears [48%]), and 4 ears had normal hearing. Intralabyrinthine hemorrhage was found in 11 of 14 ears with sudden SNHL (79%; P < .001) but occurred in none of the 17 ears with gradual SNHL or normal hearing. Tumor size was not related to SNHL (P = .23) or vestibulopathy (P = .83).
Vestibulopathy and ELST-associated SNHL may occur suddenly due to tumor-associated intralabyrinthine hemorrhage or insidiously, consistent with endolymphatic hydrops. Both of these pathophysiologic mechanisms occur with small tumors that are not associated with otic capsule invasion.