BACKGROUND A lumbar puncture constitutes an important diagnostic procedure in the evaluation of idiopathic intracranial hypertension. Chronic overflow of cerebrospinal fluid into the sheaths of the olfactory nerves appears to be related to olfactory impairment in these patients. Here, we asked whether cerebrospinal fluid drainage in idiopathic intracranial hypertension patients improves olfactory function. METHODS Fourteen idiopathic intracranial hypertension patients and 14 neurologic control patients were investigated before and after lumbar puncture using the extended Sniffin' Sticks procedure. We assessed odor threshold, discrimination, and identification. In idiopathic intracranial hypertension patients, cerebrospinal fluid was drained until cerebrospinal fluid pressure had normalized. In addition, a third group of 14 healthy controls participated in the two smell tests at similar intervals. RESULTS Relative to healthy controls, threshold, discrimination, and identification composite scores before lumbar puncture were significantly lower in idiopathic intracranial hypertension patients and also in neurologic controls. Following lumbar puncture, threshold, discrimination, and identification scores for neurologic controls remained unchanged whereas idiopathic intracranial hypertension patients showed robust improvement on the composite score as well as on all three subscores (all changes: p < 0.003), quickly regaining olfactory function in the normal range. Cerebrospinal fluid opening pressure was significantly correlated with improvement in threshold, discrimination, and identification score upon cerebrospinal fluid drainage (r = 0.609, p = 0.021). CONCLUSION Olfactory impairment is an important, yet underappreciated, clinical feature of idiopathic intracranial hypertension. Lowering of increased intracranial pressure improves hyposmia. Our findings shed new light on the pathophysiology of cerebrospinal fluid circulation in idiopathic intracranial hypertension.

中文翻译：

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腰椎穿刺可快速改善特发性颅内高压患者的嗅觉：一项队列研究。

背景腰椎穿刺构成了评估特发性颅内高压的重要诊断程序。脑脊液慢性溢出进入嗅神经鞘似乎与这些患者的嗅觉障碍有关。在这里，我们询问了特发性颅内高压患者的脑脊液引流是否能改善嗅觉功能。方法 14 名特发性颅内高压患者和 14 名神经系统控制患者在腰椎穿刺前后使用延长的 Sniffin' Sticks 程序进行了调查。我们评估了气味阈值、辨别力和识别能力。在特发性颅内高压患者中，引流脑脊液直至脑脊液压力恢复正常。此外，第三组 14 名健康对照者以相似的时间间隔参加了两次气味测试。结果 相对于健康对照，腰椎穿刺前的阈值、辨别力和识别综合评分在特发性颅内高压患者和神经系统对照中显着较低。腰椎穿刺后，神经系统控制的阈值、辨别力和识别评分保持不变，而特发性颅内高压患者的综合评分和所有三个子评分都有显着改善（所有变化：p < 0.003），迅速恢复嗅觉功能普通范围。脑脊液开放压力与脑脊液引流阈值、辨别力和识别评分的改善显着相关（r = 0.609，p = 0.021）。结论嗅觉障碍是特发性颅内高压的一个重要但未被充分认识的临床特征。降低增加的颅内压可改善嗅觉减退。我们的研究结果为特发性颅内高压脑脊液循环的病理生理学提供了新的线索。