Department of Neurology, 1st Faculty of Medicine, Charles University, Prague, Czech Republic.
Sleep Med. 2010 Jun;11(6):558-61. doi: 10.1016/j.sleep.2010.01.009. Epub 2010 May 23.
Not only patients in whom REM behavior disorder (RBD) is associated with narcolepsy, but also those with narcolepsy alone are reported to have olfactory dysfunction. We investigated if hyposmia is specific to narcolepsy with cataplexy (N-C) or if narcolepsy without cataplexy (NwC) is also associated with olfactory dysfunction.
We studied olfactory function in two groups of patients: N-C group (n=66, 26 men and 40 women; mean age 41+/-18 years), and NwC group (n=17, 7 men and 10 women; mean age 46+/-20 years). As a control group we used published normative data for particular smell tests.
Both patients with N-C and patients suffering from NwC had a significantly higher olfactory threshold (N-C group, p<0.0001; NwC group, p<0.0001) and impaired odor identification (N-C group, p<0.0001; NwC group, p<0.0001). Our results show for the first time that narcolepsy without cataplexy, where the majority of cases have normal CSF hypocretin levels, is associated with olfactory dysfunction.
It appears that also a partial loss of hypothalamic hypocretin neurons without a clear CSF level decrease can affect smell projection.
不仅 REM 行为障碍（RBD）与嗜睡症相关的患者，而且单独患有嗜睡症的患者也被报道存在嗅觉功能障碍。我们研究了嗅觉功能障碍是否是嗜睡伴猝倒（N-C）特有的，或者嗜睡不伴猝倒（NwC）是否也与嗅觉功能障碍有关。
我们研究了两组患者的嗅觉功能：N-C 组（n=66，26 名男性和 40 名女性；平均年龄 41+/-18 岁）和 NwC 组（n=17，7 名男性和 10 名女性；平均年龄 46+/-20 岁）。我们使用特定嗅觉测试的已发表的正常数据作为对照组。
N-C 组和 NwC 组患者的嗅觉阈值均显著升高（N-C 组，p<0.0001；NwC 组，p<0.0001），且气味识别受损（N-C 组，p<0.0001；NwC 组，p<0.0001）。我们的结果首次表明，即使在大多数情况下 CSF 食欲素水平正常的不伴猝倒的嗜睡症中，也存在嗅觉功能障碍。
似乎下丘脑食欲素神经元的部分丧失，即使没有明确的 CSF 水平下降，也可能会影响嗅觉投射。
