Post-traumatic anosmia. Ultrastructural correlates
B. W. Jafek, P. M. Eller, B. A. Esses and D. T. Moran
Department of Otolaryngology/Head and Neck Surgery, University of Colorado School of Medicine, Denver 80262.
Five patients suffering post-traumatic anosmia were studied at the
University of Colorado Health Sciences Center, Denver. Each patient
underwent psychophysical testing, clinical evaluation, and olfactory
biopsy. The biopsy specimens were examined ultrastructurally and were found
to vary from normal tissues. The overall appearance of the olfactory
epithelium in the post-traumatic patient is disrupted and the receptor
cells are distorted. Large numbers of axons are located near the basement
membrane and can often be found in bundles throughout the epithelium,
extending even to the mucosal surface. Olfactory cilia are rarely seen in
epithelia obtained from post-traumatic patients. Bald olfactory vesicles,
often containing basal bodies, are frequently observed. We postulate that
in these cases, the olfactory epithelium regenerates following head trauma
and the receptor cells attempt to send axons centrally. However, the
cribriform plate has undergone fibrotic healing and the axons are unable to
penetrate it and make contact with olfactory bulb neurons.
