Meniere's disease: The incidence of hydrops in the contralateral asymptomatic ear

Objective: This study analyzes the incidence of endolymphatic hydrops in th e asymptomatic contralateral ear of patients with classic Meniere's disease . Study Design: A retrospective study of 3000 subjects who underwent electr ocochleography (ECOG) from 1988 to 1998, Methods: The presence of endolymph atic hydrops was determined by use of ECOG recordings, which were made thro ugh a transtympanic recording needle situated in the round window niche, An alysis was made of the 1-kHz tone-burst summation potential (SP), and compa rison was made between asymptomatic contralateral "Meniere's ears" (n = 144 ) and asymptomatic normal "control ears" (n = 114). Results: Results demons trated that more than 10% of the contralateral asymptomatic Meniere's ears have an ECOG recording that is highly suggestive of the presence of endolym phatic hydrops. In contrast, less than 2% of the control population demonst rate abnormal ECOG recordings. Furthermore, 15% of the population of contra lateral Meniere's ears Lie above the 95th percentile of the control populat ion for 1-kHz tone-burst (100 dB) SP negativity. Conclusions: This study su ggests that a high percentage of patients who have what appears to be unila teral Meniere's disease have evidence of endolymphatic hydrops in the contr alateral asymptomatic ear. This finding has important clinical relevance fo r the management of patients in whom destructive surgery is planned and fur ther highlights the importance of electrocochleography in the diagnosis and management of this disease process.