Olfactory impairments in patients with unilateral cerebellar lesions are selective to inputs from the contralesional nostril
Olfactory impairments in patients with unilateral cerebellar lesions are selective to inputs from the contralesional nostril
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DOI：
10.1523/jneurosci.0920-05.2005
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发表时间：
2005-07-06
影响因子：
5.3
通讯作者：
Sobel, N
中科院分区：
文献类型：
--
作者：
Mainland, JD;Johnson, BN;Sobel, N
嗅觉的功能成像研究一直报道气味诱导的小脑激活。然而，小脑在嗅觉中的作用仍然未知。我们检查了单侧小脑病变患者的嗅觉和嗅觉运动能力，比较了受试者鼻孔内的表现，以及年龄匹配的受试者和年轻对照者之间的表现。关于嗅觉表现，初步测试显示，患者在嗅觉识别方面有对侧损伤，但嗅觉检测阈值没有。然而，当测试条件下，防止补偿嗅探策略，患者也表现出对侧嗅觉检测障碍。关于嗅觉运动功能，健康的嗅觉运动系统产生如下的嗅闻：（1）足够剧烈，并且（2）与嗅闻平均气流速度、最大气流速度、体积和持续时间中的气味剂浓度成反比。与对照参与者相比，患者的嗅闻在总体气流速度和体积上较低。此外，降低的吸气速度预测患者的检测阈值较差。最后，虽然年轻的对照组使用浓度依赖性嗅探，但只有年龄匹配的对照组才有这个趋势。患者使用浓度不变的嗅闻。总之，小脑病变影响嗅觉和嗅觉运动的性能。这些发现强烈暗示了嗅觉小脑通路在气味识别和检测中的突出作用，该通路在功能上将每个小脑主要连接到对侧小脑。
Functional imaging studies of olfaction have consistently reported odorant-induced activation of the cerebellum. However, the cerebellar role in olfaction remains unknown. We examined the olfactory and olfactomotor abilities of patients with unilateral cerebellar lesions, comparing performance within subjects across nostrils, as well as between subjects with age-matched and young controls. Regarding olfactory performance, initial testing revealed that patients had a contralesional impairment in olfactory identification but not olfactory detection threshold. However, when tested under conditions that prevented compensatory sniffing strategies, the patients also exhibited a contralesional olfactory detection impairment. Regarding olfactomotor function, a healthy olfactomotor system generates sniffs that are (1) sufficiently vigorous and (2) inversely proportional to odorant concentration in sniff mean airflow velocity, maximum airflow velocity, volume, and duration. Patients' sniffs were lower in overall airflow velocity and volume in comparison with control participants. Furthermore, reduced sniff velocity predicted poorer detection thresholds in patients. Finally, whereas young controls used concentration-dependent sniffs, there was a trend in that direction only for age-matched controls. Patients used sniffs that were concentration invariant. In conclusion, cerebellar lesions impacted olfactory and olfactomotor performance. These findings strongly implicate an olfactocerebellar pathway prominent in odor identification and detection that functionally connects each nostril primarily to the contralateral cerebellum.