Azuma Kenichi, Uchiyama Iwao, Tanigawa Mari, Bamba Ikuko, Azuma Michiyo, Takano Hirohisa, Yoshikawa Toshikazu, Sakabe Kou
Department of Environmental Medicine and Behavioral Science, Kinki University Faculty of Medicine, Osakasayama, Osaka, 589-8511, Japan,
Environ Health Prev Med. 2015 May;20(3):185-94. doi: 10.1007/s12199-015-0448-4. Epub 2015 Feb 15.
Multiple chemical sensitivity (MCS) is a chronic acquired disorder characterized by non-specific symptoms in multiple organ systems associated with exposure to odorous chemicals. We previously observed significant activations in the prefrontal cortex (PFC) during olfactory stimulation using several different odorants in patients with MCS by near-infrared spectroscopy (NIRS) imaging. We also observed that the patients with MCS did not adequately distinguish non-odorant in the late stage of the repeated olfactory stimulation test. The sensory recovery of the olfactory system in the patients with MCS may process odors differently from healthy subjects after olfactory stimulation.
We examined the recovery process of regional cerebral blood flow (rCBF) after olfactory stimulation in patients with MCS. NIRS imaging was performed in 6 patients with MCS and in 6 controls. The olfactory stimulation test was continuously repeated 10 times. The study also included a subjective assessment of the physical and psychological status and of the perception of irritating and hedonic odors.
After olfactory stimulation, significant activations were observed in the PFC of patients with MCS on both the right and left sides compared with controls. The activations were specifically strong in the orbitofrontal cortex (OFC). Compared with controls, autonomic perception and feelings identification were poorer in patients with MCS. OFC is associated with stimuli response and the representation of preferences.
These results suggest that a past strong exposure to hazardous chemicals activates the PFC during olfactory stimuli in patients with MCS, and a strong activation in the OFC remains after the stimuli.
多重化学敏感性（MCS）是一种慢性获得性疾病，其特征为多器官系统出现非特异性症状，与接触有气味的化学物质有关。我们之前通过近红外光谱（NIRS）成像观察到，在使用几种不同气味剂对MCS患者进行嗅觉刺激期间，前额叶皮层（PFC）有显著激活。我们还观察到，在重复嗅觉刺激测试的后期，MCS患者无法充分区分无气味物质。MCS患者嗅觉系统的感觉恢复在嗅觉刺激后处理气味的方式可能与健康受试者不同。
我们研究了MCS患者嗅觉刺激后局部脑血流（rCBF）的恢复过程。对6例MCS患者和6例对照者进行了NIRS成像。连续重复进行10次嗅觉刺激测试。该研究还包括对身体和心理状态以及对刺激性气味和享乐性气味感知的主观评估。
与对照组相比，嗅觉刺激后，MCS患者双侧PFC均观察到显著激活。在眶额皮层（OFC）激活尤为强烈。与对照组相比，MCS患者的自主感知和情感识别较差。OFC与刺激反应和偏好表征有关。
这些结果表明，过去强烈接触有害化学物质会在MCS患者嗅觉刺激期间激活PFC，刺激后OFC中仍存在强烈激活。
