Posttraumatic anosmia.

Two hundred twelve patients with traumatic anosmia had been seen at a clinic during the past 16 years. Sequelae of olfactory disorders were observed in 212 (4.2%) of the 5,000 cases seen that involved head and face injuries. The two most severe olfactory disorders were anosmia in 154 (72.6%) cases and hyposmia in 58 (27.4%) cases. The most frequent trauma site was the occipital region followed by the facial and frontal regions. Follow-up investigative results revealed olfactory improvement in eight (14%) of 56 cases. Six (10%) of the 56 cases prompted an aggravation of the olfactory problem. The fragmentation of olfactory nerve fibers appeared to be the most frequent cause of the anosmia after head injury.