Immunohistological Study of the Effects of Intranasal ZnSO4 Instillation on the Mouse Olfactory Epithelium and Olfactory Bulb / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: The purpose of this study was to evaluate the time course of functional and anatomical recovery of the olfactory epithelium (OE) and olfactory bulb (OB) following intranasal instillation of 1% ZnSO4 in mice. MATERIALS AND METHOD: Two groups of mice, normal control group (intranasal instillation of normal saline, n=6) and experimental group (intranasal instillation of ZnSO4, n=18), were studied. Tissues of olfactory pathways were obtained at 1, 3 and 5 weeks after bilateral intranasal instillation of 1%, 100 microliter ZnSO4 solution, and processed for immunohistochemistry using antisera, olfactory marker protein (OMP), proliferating cell nuclear antigen (PCNA) and tyrosine hydroxylase (TH) to evaluate the olfactory regeneration. For histological study, OE thickness stained with hematoxylin-eosin was analyzed. RESULTS: At 1 week after ZnSO4 intranasal instillation, the lowest peak of OMP expression in OE appeared. Then the number of OMP-positive cells increased progressively at weeks. However, PCNA expression in OE showed quite the opposite. In the corresponding OB at 1 week, there was decrease of TH-positive cells and at 3 weeks, there was few TH-positive cells. At 5 weeks, there was increase in the number of TH-positive cells again. OE thickness was reduced to 20% of control OE at 1 week, and was significantly recovered to 80% of control OE at 5 weeks. CONCLUSION: Our results demonstrated that intranasal instillation of 1% ZnSO4 to mice produces a brief, reversible but essentially complete destruction of functional connection from the olfactory epithelium to the main olfactory bulb.

Magnetic Resonance Imaging in Facial Nerve Palsy: Comparison between Bell's Palsy and Herpes Zoster Oticus / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Magnetic resonance imaging (MRI) is a valuable and important tool for use in diagnosing and investigating diseases affecting the facial nerve. However, there are few reports investigating the difference in the MRI findings of Bell's palsy and Ramsay Hunt syndrome. in order to evaluate the difference in the clinical values regarding these two groups of facial nerve palsy syndrome. In this study, we observed the MRI findings to investigate the value of MRI and its clinical significance in those two different groups of facial nerve palsy. SUBJECTS AND METHOD: Fourty-eight patients of Bell's palsy or herpes zoster oticus, who were admitted to Kangnam St. Mary's Hospital from January 1998 to December 2003, were selected to assess the results of gadolinium enhanced MRI. The frequency and the site of the facial nerve enhancement and its correlation with electroneuronography (ENoG), the time interval of the palsy to MRI, and initial ESR levels were observed in both groups of facial nerve palsy. RESULTS: On gadolinium enhanced MRI, 16 of 24 patients with Bell's palsy and 22 of 24 patients with herpes zoster oticus had contrast enhancement in the meatal, labyrinthine segments and geniculate ganglion. The number of enhanced segments was significantly larger in the patients with herpes zoster oticus than in the patients with Bell's palsy (p<0.05). There has been significant correlation between the number of enhanced segment of the facial nerve and the result of ENoG in the patients with herpes zoster oticus (p<0.05). CONCLUSION: Gadolinium enhanced MRI (Gd-MRI) studies may predict the extent of lesion within the course of the facial nerve and its clinical value as a prognostic factor could be suggested in patients with herpes zoster oticus