Biomedical subjects

Kentaro Ochi

Publications and source records attributed to Kentaro Ochi.

26 records · Page 2Linked to original sources

PubMed2003

Vestibular-evoked myogenic potential in patients with unilateral vestibular neuritis: abnormal VEMP and its recovery.

The incidence of inferior vestibular nerve disorders in patients suffering from unilateral vestibular neuritis and the recovery of these disorders were evaluated by monitoring the vestibular-evoked myogenic potential (VEMP). Eight patients ranged from 21 to 73 years that suffered from unilateral vestibular neuritis underwent VEMP and caloric testing. Abnormal VEMP was observed in two of the eight patients with unilateral vestibular neuritis. Two patients were diagnosed as having an inferior vestibular nerve disorder. One of these patients showed recovery of the inferior vestibular nerve function as assessed by the VEMP. Disorders of the inferior vestibular nerve function and their recovery was confirmed by our current results. The time course of recoveries of the superior and inferior vestibular nerve systems were similar in the two patients.

Adult↗

PubMed2002

The effects of an external nasal dilator and nasal dimensions in Asians.

OBJECTIVES: We examined the potential correlation between the effectiveness of an external nasal dilator for Asians and nasal dimensions. STUDY DESIGN AND SETTINGS: The length, width, and height of the subjects' nose were measured. From these parameters, a nasal index (nasal width/nasal length) and a basal view index (columella height/nasal width) were calculated. Nasal airway resistances with and without an external nasal dilator were measured. RESULTS: There was a significant correlation between both nasal index and basal view index and the changes in nasal resistance that resulted from wearing an external nasal dilator, whereas no significant correlation was detected between each of the 3 nasal dimensions and changes in nasal resistance. CONCLUSIONS: Noses with a smaller nasal index or a larger basal view index receive greater benefits from the wearing of an external nasal dilator. The effects of external nasal dilators are influenced by nasal shape rather than by individual nasal dimensions in Asians.

Adult↗

PubMed2002

Acoustic tensor tympani response and vestibular-evoked myogenic potential.

OBJECTIVE: To investigate the acoustic response properties and the vestibular-evoked myogenic potential (VEMP) in various lesions. STUDY DESIGN: Retrospective study of the clinical records of patients. METHODS: Neurotological tests including acoustic response and VEMP were performed and analyzed in 62 patients with facial palsy, otosclerosis, ossicular chain interruption, sensorineural hearing loss, or acoustic tumor. RESULTS: Inverted acoustic responses were observed in 25 of 38 (65.8%) patients with facial palsy, in 5 of 6 (83.3%) patients with acoustic tumor, and in all patients with otosclerosis, ossicular chain interruption, or sensorineural hearing loss. These inverted responses were obtained only when ipsilateral stimulation was used. The thresholds of the inverted responses were statistically significantly higher than those of the normal response. CONCLUSIONS: The vibration of the eardrum is thought to stimulate the ipsilateral trigeminal nerve, leading to contraction of the tensor tympani muscle. The stapedius response had an inhibitory effect on the inverted response. Vibration of the stapes footplate (which requires a normal middle ear conduction system) is necessary to induce the VEMP, whereas the functioning of the facial and cochlear nerves is independent of the VEMP response.

Adult↗

PubMed2002

Quinine affects the response properties of compound action potentials elicited by periodic click trains.

The effects of systemically applied quinine on the compound action potential (CAP) were investigated in 5 guinea pigs. A dose of 200 mg/kg body weight of quinine hydrochloride was administered intramuscularly, and CAPs were recorded at the round window before and after administration. The CAP thresholds of the animals were elevated by 5 to 25 dB approximately 30 minutes after administration, and thresholds recovered in some animals during the experimental session. The CAP waveform elicited by the click train stimulus was abnormal after administration of quinine. The amplitude of the CAPs elicited by the second click was larger than that of those elicited by the first click. These changes may be induced by an abnormally broadened N1 response to the first click in the click train following quinine administration. In contrast, the CAP waveforms elicited by the second click and by the following clicks in the click train appeared normal.

Acoustic Stimulation↗

PubMed2002

Effects of nimodipine on salicylate ototoxicity.

The purpose of this study was to examine the effects of nimodipine on salicylate ototoxicity in guinea pigs. The compound action potential (CAP) was recorded at the round window, and the cochlear blood flow (CBF) was measured simultaneously from the lateral wall of the basal turn of the cochlea by laser Doppler flowmetry. After administration of salicylate (100 mg/kg), the CAP thresholds were significantly elevated, by 5 to 20 dB (p < .05), and the CBF was significantly decreased (p < .05). After administration of nimodipine (2 mg/kg), the CAP thresholds were unchanged, but the CBF had increased significantly (p < .05), while systemic blood pressure had decreased significantly (p < .05). Simultaneous administration of both salicylate (100 mg/kg) and nimodipine (2 mg/kg) resulted in significant elevation of the CAP thresholds (p < .05), while the CBF did not decrease. These results suggest that nimodipine prevents the decrease in CBF induced by salicylate, but that nimodipine does not prevent the deterioration in the CAP.

Action Potentials↗

PubMedDate not supplied

Endoscopic transnasal resection of a juvenile angiofibroma using an ultrasonically activated scalpel.

We report a case of juvenile nasopharyngeal angiofibroma (JNA). A 19-year-old male came to our clinic complaining of severe nasal obstruction and epistaxis. Imaging investigations using computed tomography and magnetic resonance imaging techniques revealed a soft tissue mass in the nasopharynx with minimal extension to the pterygopalatine fossa. After embolization of the internal maxillary artery, we successfully performed endoscopic transnasal surgery for a JNA using an ultrasonically activated scalpel. Endoscopic follow-up for the 18 months after the surgical procedure revealed no evidence of recurrence or residual tumor.

Adult↗

PubMedDate not supplied

Postoperative pain in tonsillectomy: comparison of ultrasonic tonsillectomy versus blunt dissection tonsillectomy.

Intraoperative blood loss, postoperative pain, and postoperative appetite were compared between 15 adult patients who underwent tonsillectomy using an ultrasonically activated scalpel (UT) and 15 adult patients who underwent blunt dissection tonsillectomy with cold steel instruments (BT). The average intraoperative blood loss of the UT group was 4.6 +/- 1.9 ml (mean +/- standard deviation), while that of BT group was 41.9 +/- 12.9 ml. This difference was highly statistically significant (p < 0.0001). In contrast, there were no significant differences in the VAS pain and appetite scores between patients who underwent UT and those who underwent BT on any day in the 6-day postoperative period. Our current results show that UT is a safe technique, and we believe that it should be considered a useful alternative for tonsil surgery.

Adult↗

PubMedDate not supplied

Recovery of vestibular-evoked myogenic potential: relationship to other neural disorders in two patients with acute sensorineural hearing loss.

We report the recovery of the inferior vestibular neural system disorder by monitoring the vestibular-evoked myogenic potential (VEMP) in two patients suffering from acute sensorineural hearing loss with vertigo. Patients presented absent VEMP, canal paresis, and severe hearing disorder. After 10 months, the function of the inferior vestibular neural system was recovered in both cases while that of the superior vestibular neural system was recovered in one case and partially recovered in the other. In addition, the hearing sensitivity was only partially recovered in both cases. The recovery of the inferior vestibular neural system was confirmed by our current results. These results suggested that time course of recoveries of the superior and inferior vestibular neural systems, and of the cochlear neural system, were somewhat different in the two cases.

Acute Disease↗