후각사건전위 검사에서 Inter-Stimulus Interval을 줄이기 위한 교차자극방법

Abstract

There are several ways to evaluate the function of the sense of smell. Although psychophysical tests have been widely used, there is difficulty to evaluate objectively the olfactory function. The Olfactory Event-Related Potential (OERP) is considered as one of the alternative methods to test the function of the olfactory. Nonetheless, in clinical field, electrophysiological test has not been utilized generally due to long inspection time and additional apparatus. Long inspection time because of the inter-stimulus interval (ISI) is a very significant determinant of the amplitude of OERP. At ISIs below 10s, the responses are much reduced in amplitude. This reduction may be related to habituation or adaptation process. Reasonable amplitudes are recorded at ISIs ranging 40-50s. In the case OERP trials is done 15 times at 40s ISIs, the examination duration would be 10 minutes, which is relatively long as a single examination in clinic. In this study, first we designed the olfactometer which injects fragrance quantitatively for olfactory ERP experiment. Then we designed and performed the efficient OERP paradigm. The trigeminal function can be additional clinical information to the diagnosis of olfactory dysfunction because the two interact at multiple levels. Thus, it would be better to get two ERP responses for olfactory and trigeminal function with a single OERP paradigm. We test three kinds of experiment sets. First, the OERP trials using a single odorant is done 14 times at 40s ISIs. Second, the OERP trials using a single odorant is done 14 times at 20s ISIs. The last OERP test using two different stimulation which consist of olfactory and trigeminal stimulation is done 28 times at 20s ISIs. We expect that the last alternative stimulus paradigm with two odorants (one for olfactory and the other for trigeminal) would be good paradigm to reduce examination time and get clinical more information.