[Posttraumatic anosmia: olfactory event related potentials and MRI evaluation].

ABSTRACT

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.