Cochlear hydrops analysis masking procedure in individuals with normal hearing and meniere’s disease

Abstract

Meniere’s disease (MD) is an idiopathic inner ear disorder which is an abnormal increase in the volume of the cochlear fluid in the inner ear. The diagnosis of MD is always a difficult task. Cochlear hydrops analysis masking procedure (CHAMP) is one of the modified versions of auditory evoked potential test which helps in diagnosing active MD. CHAMP measures changes if any in latency of wave V in auditory brainstem response, caused by the addition of high pass masking noise to the click stimulus ipsilaterally.There were two groups of participants; control group (33 ears) with mean age 22.2 years and experimental group (30 ears) with mean age of 32.1 years were selected for the study. CHAMP was recorded for both individuals with normal hearing and with MD. The results revealed that the latency of wave V response increased with the lowering of high pass masking noise cut-off from 8 kHz to 0.05 kHz along with click stimuli in both the groups. However, the shift in latency was seen more in the individuals with normal hearing than MD. The probable reason of minimal shifting in latency of wave V in individuals with MD could be due to undermasking phenomena. In the present study, it was observed that if the cut-off latency value to diagnose MD is considered to be 1 msec rather than 0.3 msec, 62.5% normal hearing ears can be separated from MD ears. Similarly, 88.45% MD ears will have abnormal short latency shift which was confirmed the diagnosis of MD. Hence, it can be concluded that this test can be used to distinguish objectively individuals with Meniere’s disease with modification in cut-off criteria.