[Analysis of factors affecting the pure tone threshold glycerol test].

OBJECTIVE

To probe the factors that affect the pure-tone threshold glycerol test and the distribution of frequencies in positive glycerol test.

METHOD: We tested the pure-tone threshold before and after glycerol intake in patients with Meniere's disease, and then analyzed the positive rates,distribution of positive frequencies and the time when the maximum threshold changes appeared.

RESULT: The positive rate of pure-tone glycerol test was 72.09%, of which the threshold descending rate was 47.67%, and the threshold rebounding rate was 24.42%; the pure-tone threshold changes of descending group and rebounding group were (17.41 +/- 9.92) dB, (13.53 +/- 4.64) dB respectively, and the differences were significant. The distribution of positive frequencies were 250 Hz, 125 Hz, 500 Hz, 1 kHz, 4 kHz, 2 kHz, 8 kHz in descending order. The maximum pure-tone threshold changes mostly appeared within 2 or 3 hours after glycerol intake.

CONCLUSIONS

Patient selection, test occasion and the judgement criteria may affect the positive rate of glycerol test; the positive frequencies distribute in the low-frequency region mainly; the maximum pure-tone threshold changes mostly appeared within 2 or 3 hours after glycerol intake.