Post-traumatic olfactory dysfunction.
OBJECTIVE
This study demonstrates histopathologic and immunocytochemical changes in the olfactory bulb of a patient with post-traumatic olfactory dysfunction. These results are analyzed in light of current understanding of the pathophysiology of anosmia and dysosmia following head trauma. Emphasis is placed on potential mechanisms of human regeneration and recovery.


METHODS
The current study documents the history of a patient with the initial complaint of complete anosmia following minor head trauma. Two months after the injury the patient developed persistent, severe dysosmia with debilitating weight loss. Neurosurgical treatment, including removal of the olfactory bulbs and tracts, resulted in permanent resolution of dysosmia.


METHODS
Histopathologic and immunocytochemical analysis of the olfactory bulbs was undertaken and compared with age-matched control tissue.


RESULTS
Pathological analysis of the olfactory bulb revealed a marked reduction in the number of nerve processes with few intact olfactory glomeruli compared with an age-matched control. Specific immunohistochemical staining for the olfactory neuron-specific protein OMP, however, demonstrated the presence of intact axonal projections between the olfactory mucosa and the bulb.


CONCLUSIONS
These results support the hypothesis that post-traumatic anosmia involves, at least in part, damage to peripheral olfactory nerve fibers with histological changes in the olfactory bulb. Potential mechanisms for the development of post-traumatic dysosmia are also discussed.
Kern
R C
RC
Department of Otolaryngology-Head and Neck Surgery, Northwestern University, Chicago, Illinois 60611, USA.
Quinn
B
B
Rosseau
G
G
Farbman
A I
AI
D000328:Adult; D016489:Head Injuries, Closed / Q000150:complications; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D000857:Olfaction Disorders / Q000209:etiology / Q000473:pathology* / Q000503:physiopathology; D009830:Olfactory Bulb / Q000473:pathology*; D061219:Olfactory Nerve Injuries