Masahito Tsubota

Epidemiologic characteristics of definite Ménière's disease in Japan : A long-term survey of toyama and niigata prefectures

To identify epidemiologic characteristics of definite cases of Ménière’s disease (DMD), we conducted retrospective surveys of the period 1990–2004 of the Nishikubiki district and of the period 1980–2004 of Toyama Medical and Pharmaceutical University. Three hundred and seventy-five patients (50 from Nishikubiki, 325 from Toyama) were diagnosed with DMD according to the diagnostic criteria proposed by the Japanese Society for Equilibrium Research. There was a slight increase in the prevalence of DMD during the period 1990–2004. However, incidence did not change significantly over time. The average annual prevalence and incidence were 34.5 and 5.0, respectively, per 100,000 population. Incidence and prevalence predominated in females. With respect to age at disease, the incidence in elderly patients was increased when we corrected for age distribution in the overall population.

Positron emission tomography for predicting malignancy of sinonasal inverted papilloma.

Background: Sinonasal inverted papilloma (IP) is an uncommon nasal tumor. It is known for being locally invasive and recurrent, with a high probability of malignant transformation. Accurate initial staging and close surveillance are critical in the management of the disease. Methods and Results: Fluorine-18 fluorodeoxyglucose positron emission tomography (FDG PET) was performed in 5 patients with IP. High FDG uptake (maximum standardized uptake (SUVmax) value >3.0) was observed in all patients, and 2 patients with IP associated with squamous cell carcinoma (SCC) exhibited higher SUVmax values. Conclusion: The SUVmax value of a sinonasal tumor can warn the surgeon of the probability of an associated malignancy, even when preoperative biopsy demonstrates a purely benign papilloma.

Prognosis of inner ear function in pneumolabyrinth: case report and literature review

Pneumolabyrinth, the presence of air within the labyrinth, is a rare radiologic finding associated with a well-known perilymphatic fistula (PLF). As there are only 24 published case reports in medical literature, multiple treatment options for the pneumolabyrinth are available. We report a case of a 20-year-old man with a pneumolabyrinth secondary to tympanic membrane and ossicular trauma. Despite conservative treatment, sensorineural hearing loss (SNHL) had progressed rapidly, and his profound deafness had not recovered after surgical exploration with closure of the PLF. Functional prognostic factors of SNHL are revised and compared with this case.

Mumps virus may damage the vestibular nerve as well as the inner ear

We report a case of mumps deafness with acute vestibular symptoms secondary to both retrolabyrinthine and inner ear dysfunction. To our knowledge, no such case has been reported elsewhere. The patient was a 6-year-old girl in whom mumps deafness was initially diagnosed. Two days after onset of the hearing impairment, severe vertigo developed. Neurotologic examinations revealed spontaneous right-beating nystagmus, left canal paresis, absence of vestibular-evoked myogenic potentials in the left ear, and absence of responses to a left galvanic body sway test (GBST). The vertigo resolved 7 days after onset. However, the left hearing impairment progressed to complete deafness. Six months later, left canal paresis was still present, but bilateral GBST responses were normal, suggesting that retrolabyrinthine vestibular function had been restored. Mumps virus may affect retrolabyrinthine function as well as the inner ear.

Long-term effects of the Meniett device in Japanese patients with Meniere's disease and delayed endolymphatic hydrops reported by the Middle Ear Pressure Treatment Research Group of Japan

Abstract Conclusion: The Meniett device is a minimally invasive and safe treatment that may be used to provide longer-term reduction of vestibular symptoms in patients with delayed endolymphatic hydrops (DEH) as well as those with Menieres disease (MD). Objective: The effects of the Meniett device were evaluated in patients with a diagnosis of definite MD or DEH according to the 1995 AAO-HNS criteria. Methods: Twenty-nine ears of 28 patients with MD and 5 ears of 5 patients with DEH (ipsilateral type 4, contralateral type 1) were treated with the Meniett device by the Middle Ear Pressure Treatment Research Group of Japan. All of the patients had failed to respond to medical treatment including diuretics before the pressure treatment. Results: Sixteen (57%) patients with MD and all five (100%) patients with DEH remained entirely free from vertigo spells; nine (32%) patients with MD responded with a significant decrease in the frequency of vertigo spells. In regard to hearing, 25 ears (74%: MD, n = 21; ipsilateral DEH, n = 4) had stable hearing levels; only 4 ears (12%: MD, n = 3; contralateral DEH, n = 1) showed a significant hearing improvement. No complications were attributable to the Meniett device.

Effects of vestibular nerve section on sound-evoked myogenic potentials in the sternocleidomastoid muscle of monkeys

OBJECTIVE The aim of this study was to elucidate the neural pathway for sound-evoked myogenic potentials (SEMPs) in monkeys with characteristics similar to those of vestibular evoked myogenic potentials in humans. METHODS Six macaque monkeys were examined. The effects of total and selective vestibular nerve section on the SEMPs were evaluated in three monkeys. RESULTS After total vestibular nerve section, the SEMPs and caloric nystagmus were eliminated, and the auditory brainstem response remained. After selective superior vestibular nerve section, the SEMPs remained, but caloric nystagmus was eliminated. CONCLUSIONS The inferior vestibular nerve comprises a neural pathway for SEMPs in monkeys. SIGNIFICANCE SEMP in monkeys may provide a model of human VEMPs.

Intermittent pressure therapy of intractable Meniere's disease and delayed endolymphatic hydrops using the transtympanic membrane massage device: a preliminary report.

Abstract Conclusion. Middle ear pressure treatment by the tympanic membrane massage (TMM) device as well as the Meniett device is effective and provides minimally invasive options for intractable vertigo in patients with Menieres disease (MD) and delayed endolymphatic hydrops (DEH). Objective: The effects of the TMM device were evaluated according to the criteria of the Japan Society for Equilibrium Research (1995) in patients with MD and DEH and compared to those in patients treated with the Meniett device. Methods: Twelve ears of 10 patients (MD 8; DEH 2) were treated with the TMM device, while 16 ears of 15 patients (MD 11; DEH 4) were treated with the Meniett device. All the patients had failed to respond to medical treatment including diuretics before each pressure treatment, and were followed up for more than 12 months after treatment. Tympanotomy is necessary before treatment for the Meniett device, not but for the TMM device. Results: With both devices, the frequency of vertigo after treatment was significantly lower than before treatment (p < 0.05). The time course of vestibular symptoms with the TMM device was not significantly different from that with the Meniett device (p > 0.05). No complications were directly attributable to treatment with the TMM device.

Effects of selective cochlear toxicity and vestibular deafferentation on vestibular evoked myogenic potentials in guinea pigs

Conclusion: The findings suggest that sound-evoked myogenic potentials on the guinea pig sternocleidomastoid muscle (SM) originate from the vestibular end organ and not from the cochlea of the inner ear. Objective: Studies in animals of the sound evoked vestibular myogenic potentials on the SM should aid in elucidating the pathway of the vestibular-evoked myogenic potential (VEMP). However, details of the pathway of the VEMP remain to be elucidated. This study aimed to clarify aspects of this pathway. Materials and methods: In the present study, short latency biphasic myogenic potentials on the SM in guinea pigs were induced by an intense brief sound. Results: The thresholds of the potentials were 67 dB SPL above those of the auditory brainstem response (ABR). The potentials were eliminated by a vestibular deafferentation, but were observed after selective cochlea toxicity using an amikacin injection.

Sound-evoked myogenic potentials on the sternocleidomastoid muscle in monkeys

Conclusion. We recorded sound-evoked myogenic potentials of the sternocleidomastoid (SCM) muscle using awake monkeys. The characteristics of these potentials are similar to those of vestibular evoked myogenic potentials (VEMPs) in humans, suggesting that the sound-evoked myogenic potentials of the SCM muscle in monkeys may be utilized as an animal model of VEMPs. Objective: The pathway of the VEMPs remains uncertain as no animal model has yet been used to record sound-evoked myogenic potentials in the SCM muscle. Therefore, the present study aimed to establish an animal model of VEMPs using macaque monkeys. Materials and methods. Four macaque monkeys were used. A pair of electrodes was attached on the SCM muscle ipsilateral side to the intense sound stimulation. Results. The sound-evoked myogenic potentials of the SCM muscle exhibited a biphasic waveform. When a click at 125 dBSPL was applied, the peak latency of the first positive wave was 12.5 ms and was not delayed when the stimulating sound intensity was reduced. The thresholds of the myogenic potentials were 103 dBSPL, which were 43 dB higher than those of the auditory brainstem response (ABR). When a short tone burst was applied, the reactive optimal frequency of the myogenic potentials was relatively low (500–1000 Hz).

Application of hyperdry amniotic membrane patches without fibrin glue over the bony surface of mastoid cavities in canal wall down tympanoplasty.

Abstract Conclusion: Fibrin glue might be an inessential bioadhesive for attachment of hyperdry amniotic membrane (AM) patches in canal wall down (CWD) tympanoplasty. Objective: To clarify the pliability and adherence capability of human hyperdry AM, the feasibility of fixing hyperdry AM without fibrin glue to the bony surface of the mastoid cavity was evaluated in CWD tympanoplasty. Methods: This was a retrospective chart review. In seven ears of seven patients, the AM was simply attached over the bony surface of the mastoid cavity without fibrin glue (AMG(–) group). In 22 ears of 20 other patients, hyperdry AM (11 ears of 11 patients, AMG(+) group) or temporal fascia (11 ears of 9 patients, TFG(+) group) was attached over the bony surface of the mastoid cavity with fibrin glue. Times for graft epithelization were compared among the three groups. Results: Complete epithelization of the mastoid cavity took place in all patients in all three groups. The mean time to complete epithelization of the graft in the AMG(–) and AMG(+) groups was significantly faster than that in the TFG(+) group (p < 0.05) and was not significantly different between the two AM groups (p > 0.05).