Gait instability caused by vestibular disorders - analysis by tactile sensor.

OBJECTIVE: To elucidate instability of gait performance in patients with vestibular lesions by the use of a tactile sensors placed under both feet. METHODS: Gait analysis was conducted by the use of tactile sensors in 92 patients who had various types of vestibular lesions including vestibular neuritis (VN), acoustic neuroma (AN), and spinocerebellar degeneration (SCD). 26 healthy adults served as a control. Variables were coefficient of variation of stance, swing, and double support durations. Morphological analysis of foot pressure progression during stance was also performed. In addition, differences in each foot's integrated foot pressure in a gait test were measured, especially in cases with unilateral vestibular lesions. All data was comparatively analyzed between each pathological group and control group. A comparative study between intact side foot and lesion side foot was performed in those unilateral vestibular disorder cases as well. RESULTS: Those gait phase related variables were significantly greater in the pathologic group than in the control group, especially under gait with eyes closed. Morphological irregularity of foot pressure progression during stance was shown in cases with VN and SCD and was greatest in SCD cases. As for integrated foot pressure, in most cases with VN, it has become greater in the lesion side foot, suggesting that body center of gravity could shift toward the lesion side during gait. CONCLUSIONS: Gait analysis by the use of tactile sensors could provide additional important information regarding vestibular patho-physiology in patients with vestibular system disorders. Accordingly, gait performance tests should also be taken into consideration as a vestibular function test for patients with vertigo.

Insulin-like growth factor 1 protects vestibular hair cells from aminoglycosides.

This study investigated the therapeutic potential of insulin-like growth factor-1 (IGF-1) for vestibular hair cells using explant cultures of mouse utricles. After incubation with the ototoxic drug gentamicin, explants from neonatal mouse utricles were cultured in medium containing IGF-1 at various concentrations. Histological evaluation revealed significant increases in the number of surviving hair cells cultured with IGF-1 at concentrations reflecting a clinical setting. Immunostaining for trio-binding protein and espin showed the maintenance of functional structures in hair bundles at the apex of surviving hair cells. An FM1-43 assay indicated the presence of mechanoelectrical transduction channels in surviving hair cells. These findings indicate that IGF-1 may protect the functionality of vestibular hair cells against drug-induced injury.

When should MRI be recommended for the accurate clinical staging of base of tongue carcinoma?

BACKGROUND AND PURPOSE: According to the American Joint Committee on Cancer (AJCC) cancer staging criteria (6th edition), cross-sectional imaging for base of tongue carcinoma is recommended when the deep tissue extent of a primary tumor is in question. The aim of this study was to establish which group of patients MRI might most benefit from accurate clinical staging of base of tongue carcinomas. PATIENTS AND METHODS: The clinical stagings of 33 patients with pathologically proven squamous cell carcinomas of the base of tongue were performed by two otorhinolaryngologic surgeons. Their results were compared with the results from MRI interpreted by a neuroradiologist and the numbers of patients being upstaged, downstaged or with an unchanged stage were recorded and analyzed. RESULTS: The tumor stages were changed in 13 of 33 patients (39.4%, 95% CI: 23.9-57.87%) and the overall stage groupings were changed in 10 (30.3 %, 95%CI: 15.6-48.7%) after performing MRI. Mis-staging by clinical examination in the overall stage grouping was as high as 83.3% (95%CI: 35.9-99.6%) in stages II and III and 85.7% (95% CI: 42.1-99.6%) in T3. CONCLUSION: MRI should be recommended in base of tongue carcinoma whenever clinical examination suggests overall stage groupings II, III or tumor stage T3.