外伤后失嗅患者的嗅觉事件相关电位和MRI评估

Posttraumatic anosmia： offactory event related potentials and MRI evaluation

目的探讨嗅觉事件相关电位（olfactory event related potentials, OERP） 和嗅觉通路MRI对外伤后失嗅的评估价值。方法回顾性分析24例外伤后失嗅患者的临床资料。所有患者均行详细的病史采集、全面体检、T＆T嗅觉检查、鼻内镜检查、OERP测试、颅脑CT和嗅觉通路MRI检查。结果主观嗅觉测试：双侧完全失嗅20例；单侧完全失嗅，对侧嗅觉减退2例；单侧完全失嗅，对侧嗅觉正常2例。OERP测试：双侧最大嗅刺激均不能引出OERP者20例，单侧最大嗅刺激不能引出OERP者4例；单侧能引出OERP者4例，其中2例能正常引出，另2例OERP幅值下降且潜伏期延长。氨气刺激均能引出鼻内三叉神经化学感受事件相关电位。嗅路MRI检查：嗅球损伤24例次（100％），额叶直回损伤22例次（91．7％），额叶眶回损伤16例次（67％），远端嗅束和颞叶损伤各2例次（8％）。结论OERP能对外伤后嗅觉进行定性和定量的客观整体评估；嗅路MRI能对外伤后失嗅的损伤部位、程度进行客观、精确的评估。两者结合能对嗅觉功能进行全面、客观评价。

Objective Using olfactory event related potentials （OERP） and magnetic resonance to evaluate olfactory function in patients with posttraumatic anosmia. Methods Twenty four patients with posttraumatic anosmia were reviewed retrospectively. A thorough medical history, physical examination, nasal endoscopy, T＆T olfactory testing, olfactory event-related potentials, brain computed tomography scan and magnetic resonance image of olfactory pathway were performed in all patients. Results Subjective olfactory testing indicated 20 of 24 patients were birhinal anosmia, 2 with right nostril anosmia and left impairment, 2 with left anosmia and right normal. No OERP were obtained in 24 （20 were birhinal, 4 was monorhinal）, except 4 cases with single nostril. Magnetic resonance imaging revealed the injures to the olfactory bulbs （ 100% ）, rectus gyrus （ 91.7% ）, orbital gyrus （ 67% ）, olfactory tracts （ 8% ） and temporal lobes （8%）. Conclusions OERP can objectively evaluate posttraumatic olfactory function, and magnetic resonance of olfactory pathway can precisely identify the location and extent of injures.