Abstract
The oral glycerol test is useful to diagnose endolymphatic hydrops. The test is known to indicate positive results in almost 50% of the patients with Meniere's disease. However, it prohibits food intake before the test, requires a long examination time, and is associated with side effects such as headache, nausea and vomiting. The intravenous glycerol test is known to have no such disadvantages. We examined here, the usefulness of the intravenous test.
The intravenous glycerol test was performed in 30 ears of 30 cases of Meniere's disease. Audiometry was carried out before the administration. A total amount of 100 ml Glyceol (10% glycerol) was intravenously injected over 30 min. Audiometry was also performed immediately after, and then 1 hour and 3 hours after the injection. Before the examination, food intake was not prohibited. A positive result was defined as a threshold improvement of the audiogram of 10 dB or more in at least 2 frequencies.
Positive results were observed in 11 of 30 ears (36.7%) immediately after the injection, in 15 of 30 ears (50.0%) 1 hour later, and in 10 of 20 ears (50%) 3 hours later. The positive ratio 1 hour later was almost the same as that of the oral glycerol test, which was previously described. Thus, the injection test can evaluate the disease 1 hour after the administration without prohibition of food intake before the test. No side effects such as headache, nausea or vomiting were observed in any case.
The intravenous glycerol test has the following advantages compared to the oral test: it does not prohibit food intake before the test, the examination time is shortened, and it is not associated with side effects.
