Change of Otoacoustic Emissions in Early Stage of Meniere's Disease

ABSTRACT

BACKGROUND AND OBJECTIVES: To determine the clinical application of otoacoustic emissions (OAE) in screening of cochlear function, author studied changes of OAE in Meniere's disease patients. MATERIALS AND METHODS: The author has measured several parameters of OAE with 34 meniere's patients and 15 normal persons. Pass rate, response amplitude, reproducibility were recorded at TEOAE. Amplitude of DP-gram were measured at 2 F2 frequencies-1000, 2000 Hz. The input/output functions of DPOAE were recorded at 2 F2 frequencies -1001, 2002 Hz (respectively DP-1000, DP-2000). Input/output function were determined based on 2 parameters- maximal level and Detection threshold of DPOAE. RESULTS: 1) TEOAE: Significant lower rate of positive finding was recorded at involved ears (55.8%, 19/34) than normal ears (100%, 30/30). 2) DP-gram: At frequency was 2000 Hz, amplitude of involved ears (n=28, 6.3+/-.5 dB/SPL) was significant smaller than normal ears (n=30, 6.3+/-.5 dB/SPL). 3) DP-input/output function: At maximum DP level of DP-2000, response of involved ears (n=11, 51.6+/-.9 dB/SPL) was significant larger than normal ears (n=22, 48.5+/-.0 dB/SPL). CONCLUSION: Parameters of OAE, such as pass rate of TEOAE, amplitude of DP-gram at 2000 Hz, and maximum DP level of DP-2000 was considered to good indicators for monitoring cochlear function of Meniere's disease. Furthermore, evaluation by changes in the TEOAE & DPOAE combined parameters, appeared to be very useful for detection of subtle change in cochlear function of Meniere's disease.