Cochlear Hydrops Analysis Masking Procedure Results in Patients With Unilateral Meniere's Disease

Objective: To investigate the usefulness of the cochlear hydrops analysis masking procedure (CHAMP) as an additional diagnostic test in patients with definite unilateral Meniere's disease. Study Design: Prospective validation study for a diagnostic test. Setting: Tertiary referral center. Patients: Subjects (n = 22) with definite unilateral Meniere's disease. Interventions: The CHAMP test was performed in both ears of the patients. Main Outcome Measure: Difference in latency delay between the affected and the unaffected ears. Results: In 20 subjects, latency delays could be measured in both ears. The mean latency delay for the affected ears (0.55 ms; standard error, 0.12 ms) differs significantly from that for the unaffected ears (3.36 ms; standard error, 0.43 ms). With the standard criterion to separate ears with an abnormally short delay (<0.3ms) from ears with a normal delay, in only 7 of 20 affected ears, an abnormally short delay was measured. All 33 other ears produced a normal delay. With the less than 0.3 ms criterion and including the ears in which no delay could be measured, the sensitivity of the CHAMP is 32% (7/22). Pooling CHAMP latency delays for 235 ears from this work and the literature yielded 2 clearly distinct distributions, with a separation at 2 ms. Defining abnormal delays as shorter than 2 ms gave an abnormal delay for 18 of 20 affected ears and for 7 of 20 unaffected ears. Conclusion: Abnormal latency delays for CHAMP are delays shorter than 2 ms. Earlier results with CHAMP should be reconsidered using this criterion, instead of 0.3 ms.