[Electrocochleography in the diagnosis of Meniere's disease].

OBJECTIVE

To evaluate clinical value of electrocochleography in diagnosing the Meniere's disease.

METHOD

Patients were saperated as having definite, probable and possible Meniere's disease according to the 1995 AAOHNS guidelines. Then set the probable and possible Meniere's disease as a suspected group. We used four different stimulus (clicks, 1000 Hz tone burst, 2000 Hz and 4000 Hz tone burst) to record electrocochleo-graphy. Those patients in each group received electrocochleography examination, and summating potential (SP)/action potential (AP) ratios were calculated. A prolonged action potential latency shift (AP shift) evoked by rarefaction and condensation clicks was also measured.

RESULT

The click SP/AP positive rate in definite Meniere's disease group was 41.2%, tone burst at 1,000 Hz. 2,000 Hz,4,000 Hz were respectively 80.4%, 72.5%, 37.3%, AP shift positive rate was 45.1%. Using McNemar test, the positive rate of tone burst 1000 Hz (chi2 = 15.04, P < 0.01) and that of tone burst 2,000 Hz (chi2 = 8.65, P < 0.01) were statistically significant different when compared with that of click SP/AP, besides the tone burst at 1,000 Hz yielded has the highest sensitivity. The click SP/AP positive rate in suspected group and definite group were respectively 12% and 45.1% (chi2 = 6.610, P < 0.05) and AP shift positive rate of them were respectively 8.0% and 41.2% (chi2 = 10.460, P < 0.01). By chis-quare test, the positive rates of click SP/AP and AP shift between these two groups were statistically significant different.

CONCLUSION

Electrocochleography is a reliable test in the diagnosis of Meniere's disease. Compared with clicks, tone burst significantly has a higher sensitivity, especially at 1000Hz and 2000Hz frequencies. A prolonged action potential latency shift evoked by rarefaction and condensation clicks is also a useful addition to diagnosis Meniere' disease.