1/2. Post-traumatic olfactory dysfunction.OBJECTIVES: 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. STUDY DESIGN: 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.- - - - - - - - - - ranking = 1keywords = post-traumatic (Clic here for more details about this article) |
2/2. Anosmia following head trauma: preliminary study of steroid treatment.Twenty patients with post-traumatic anosmia were subjected to olfactory function testing, including olfactory acuity tests using a T & T olfactometer and an intravenous olfaction test. T & T tests revealed complete loss in 14 patients. In the intravenous olfaction test, 14 patients showed no response and 5 patients showed abnormal responses. The severity of olfactory dysfunction showed no correlation with background factors such as the site of head trauma, the presence of the fracture of skull, the presence of unconsciousness, or the presence of head operation. As a preliminary study, seventeen patients were administered a corticosteroid, a topical nasal drop of 0.1% betamethasone for 12 patients and an oral administration of prednisolone for 5 patients. Four patients showed slight recovery of olfactory function following a corticosteroid therapy. Effects of corticosteroids on olfaction might be explained by regeneration of olfactory receptor cell axons and reestablishment of contact with cells in the olfactory bulb.- - - - - - - - - - ranking = 0.33333333333333keywords = post-traumatic (Clic here for more details about this article) |