Effect of edaravone on streptomycin-induced vestibulotoxicity in the Guinea pig.

OBJECTIVES/HYPOTHESIS: The effect of topical administration of edaravone to the inner ear was investigated in guinea pigs with streptomycin-induced vestibulotoxicity. METHODS: Vestibulotoxicity was induced in 20 animals by delivery of streptomycin into the inner ear through osmotic pump for 24 hours. Edaravone (n = 8, systemic administration group) or saline (n = 6, control group) was injected intraperitoneally once a day for 7 days or edaravone-soaked Gelfoam was placed on the round window before wound closure (n = 6, topical administration group). RESULTS: Yaw head tilt and spontaneous nystagmus were observed in all animals after the operation. The number of spontaneous nystagmus beats in the topical administration group was statistically less than that in other two groups at 12, 18, and 24 hours after the operation. CONCLUSION: The study results suggest that topical administration of edaravone better suppresses streptomycin-induced vestibulotoxicity than systemic administration.

[Surgical reconstruction of the common carotid artery by an ePTFE graft for invasive thyroid cancer: a case report].

Surgical reconstruction of the carotid artery using a synthetic graft is rarely performed. A 71-year-old woman developed hoarseness and was diagnosed as having thyroid cancer. Computed tomography (CT) and angiography revealed an irregular thyroid tumor invading the left common carotid artery, and encasement of the artery by the tumor. Left common carotid angiography showed an irregularity of the common carotid artery wall and a dense tumor stain fed by the superior thyroid artery. Dissection of the thyroid cancer from the common carotid artery was judged to be impossible during surgery, so resection of the whole tumor together with the common carotid artery was carried out. The left common carotid artery was reconstructed using an expanded polytetrafluoroethylene (ePTFE) graft. No cerebral ischemia was evident after surgery. Postoperative CT and magnetic resonance angiography demonstrated patency of the carotid artery, and no tumor recurrence was confirmed at a 27-month follow up. The ePTFE graft appears to be a suitable synthetic graft for reconstruction of the carotid artery.

[Internet survey of the relationship between vertigo and stress].

We studied the relationship between vertigo and stress, using an internet survey. A questionnaire posted on our homepage quantified and measured 4 categories: cause of anxiety, behavioral characteristics, mean of relaxation, and frequency of vertigo. There were 6065 responses. Scores for the cause of anxiety were significantly greater and scores of means of relaxation were less in older than younger respondents. Scores for the cause of anxiety and behavioral characteristics were singificantly greater in more frequent than less frequent vertigo. Scores for means of relaxation were less in frequent vertigo. These findings indicate an intimate relationship between the onset of vestibular disorder and stress.

Protective effect of edaravone against streptomycin-induced vestibulotoxicity in the guinea pig.

This study investigated alleviation of streptomycin-induced vestibulotoxicity by edaravone in guinea pigs. Edaravone, a free radical scavenger, has potent free radical quenching action and is used in clinical practice to treat cerebral infarction. Streptomycin was administered to the inner ear by osmotic pump for 24 h, and edaravone (n=8) or saline (n=6) was intraperitoneally injected once a day for 7 days. We observed horizontal vestibulo-ocular reflex as a marker of postoperative vestibular function. Animals injected with saline showed statistically smaller gains than those injected with edaravone. These results suggest that edaravone suppresses streptomycin-induced vestibulotoxicity.