Can You Smell That Smell

Question:   A 38 year old female was involved in a motor vehicle accident and sustained blunt trauma to the nose and forehead.  She did not have any signs of clear rhinorrhea, severe epistaxis, or orbital injury.  Her vision was normal and no telecanthus was noted on examination.  She presents to you 2 months after her injury with persistent anosmia.  She denies nasal obstruction.  What is the most likely etiology of her complaint?  [Answer will be posted with next week's new question]

Answer to last week's question, The (W)hole Story (January 4, 2016): 

MRI of the IACs.  Asymmetric sensorineural hearing loss in this patient is unexplained by his history and warrants a study to rule out retrocochlear pathology.