Stuck B A, Frey S, Freiburg C, Hörmann K, Zahnert T, Hummel T
Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital Mannheim, Mannheim, Germany.
Clin Neurophysiol. 2006 Jun;117(6):1367-75. doi: 10.1016/j.clinph.2006.03.004. Epub 2006 May 2.
For chemosensory event-related potentials (ERP) significant effects of age and sex have been demonstrated. The aim of the present study was to assess the effects of stimulus concentration, side of stimulation, and sex on the topographical distribution of chemosensory ERP in a large group of subjects stratified for different age groups. In addition, psychophysical measures of both olfactory and trigeminal function should be assessed in greater detail compared to previous work.
A total of 95 healthy subjects participated in the study. Olfactory functions were tested using the 'Sniffin' Sticks' comprising tests of odor identification, odor discrimination, and odor threshold. Trigeminal sensitivity was assessed on a psychophysical level using a lateralization paradigm. ERP to the olfactory stimulant H2S and the trigeminal irritant CO2 were recorded; stimuli were presented in different concentrations to the left and right nostril.
Olfactory thresholds exhibited an age-related increase while the outcome of psychophysical trigeminal tests was not significantly affected by age. In contrast, there was no significant main effect of the factor 'sex' for olfactory tests, while women scored higher than men in the trigeminal task. ERP to olfactory and trigeminal stimuli exhibited a relationship to stimulus concentration, age, and sex with youngest women showing largest amplitudes and shortest latencies. There was no significant main effect of left- or right-sided stimulation on ERP. Measures of olfactory function were found to correlate with parameters of olfactory ERP even when controlling for the subject's age. In addition, correlations between scores in the lateralization task and parameters of the trigeminal ERP were found.
Based on electrophysiological data obtained in a large sample size the present results established an age-related loss of olfactory and trigeminal function, which appears to be almost linear. Further, the present results emphasize that responses to chemosensory stimuli are related to sex, while the side of stimulation does not play a major role in the presently used paradigm. Finally, these data establish the lateralization paradigm as a psychophysical tool to investigate intranasal trigeminal function.
The present results obtained in a representative group of healthy subjects establishes a comprehensive set of data, which will serve as reference for future work in this area of research.
化学感觉事件相关电位（ERP）已显示出年龄和性别的显著影响。本研究的目的是在按不同年龄组分层的一大群受试者中，评估刺激浓度、刺激侧别和性别对化学感觉ERP地形分布的影响。此外，与以往研究相比，应更详细地评估嗅觉和三叉神经功能的心理物理学指标。
共有95名健康受试者参与本研究。使用“嗅棒”测试嗅觉功能，包括气味识别、气味辨别和气味阈值测试。使用偏侧化范式在心理物理学水平上评估三叉神经敏感性。记录对嗅觉刺激物硫化氢（H2S）和三叉神经刺激物二氧化碳（CO2）的ERP；以不同浓度将刺激物呈现给左右鼻孔。
嗅觉阈值呈现与年龄相关的升高，而心理物理学三叉神经测试结果未受年龄显著影响。相比之下，嗅觉测试中“性别”因素没有显著的主效应，而在三叉神经任务中女性得分高于男性。对嗅觉和三叉神经刺激的ERP表现出与刺激浓度、年龄和性别的关系，最年轻的女性表现出最大的振幅和最短的潜伏期。左侧或右侧刺激对ERP没有显著的主效应。即使在控制受试者年龄后，也发现嗅觉功能指标与嗅觉ERP参数相关。此外，还发现了偏侧化任务得分与三叉神经ERP参数之间的相关性。
基于在大样本量中获得的电生理数据，本研究结果证实了嗅觉和三叉神经功能与年龄相关的衰退，且这种衰退似乎几乎呈线性。此外，本研究结果强调对化学感觉刺激的反应与性别有关，而在目前使用的范式中刺激侧别不起主要作用。最后，这些数据确立了偏侧化范式作为研究鼻内三叉神经功能的心理物理学工具。
在一组具有代表性的健康受试者中获得的本研究结果建立了一套全面的数据，将为该研究领域未来的工作提供参考。
