Objective: To report a series of patients with isolated congenital anosmia and summarize their clinical and magnetic resonance imaging (MRI) characteristics.
Methods: Twenty patients with isolated congenital anosmia were reviewed retrospectively. A thorough medical and chemosensory history, physical examination, nasal endoscopy, T&T olfactory testing, olfactory event-related potentials, sinonasal computed tomography scan and magnetic resonance image of olfactory pathway were performed in all patients.
Results: Neither ENT physical examination nor nasal endoscopy was remarkable. Subjective olfactory testing indicated all of them were of anosmia. No olfactory event-related potentials to maximal stimulus were obtained. Computed tomography scan was normal. MRI revealed the absence of olfactory bulbs and tracts in all cases. And hypoplasia or aplasia of olfactory sulcus was found in all cases. All the patients had normal sex hormone level.
Conclusion: The diagnosis of isolated congenital anosmia is established on chief complaints, physical examination, olfactory testing and olfactory imaging. MRI of olfactory pathway is indispensable.