Takayuki Kawashima

Successful cochlear implantation in prelingual profound deafness resulting from the common 233delC mutation of the GJB2 gene in the Japanese

Objectives Recently, we identified three novel mutations of the GJB2 gene in Japanese families with autosomal‐recessive non‐syndromic deafness. 1 Seven of 11 mutated chromosomes (63.6%) contained a 233delC allele, suggesting that the 233delC mutation is the most common mutation of the GJB2 gene in the Japanese population. After it was recognized that cochlear implantation (CI) is of benefit to children with prelingual deafness, we have had a number of prelingual pediatric CI patients. Because children carrying the homozygous 233delC mutation show bilateral prelingual profound deafness, they could be enrolled in the CI program at Osaka University Graduate School of Medicine. The purposes of this study were 1) to analyze the occurrence of the GJB2 mutations in our 15 prelingual pediatric CI patients in whom the cause of non‐syndromic deafness was unknown, and 2) to evaluate the auditory function and postoperative speech perception with CI of those GJB2‐related deaf subjects.

Tinnitus as a prognostic factor of sudden deafness

Conclusions. The ‘tinnitus-rare’ group had a poorer prognosis for hearing than the ‘tinnitus-often’ group in all sudden sensorineural hearing loss (SSNHL), although the ‘shorter duration’ group had better prognosis than the ‘longer duration’ when restricted to SSNHL accompanied by tinnitus. This indicates that tinnitus itself may not be a sign for poor hearing prognosis but might be an essential sound for the initiation of repair of a damaged auditory system. Objectives. We examined the hearing improvement rate (HIR) and tinnitus at the onset of SSNHL to elucidate the prognostic value of tinnitus accompanying SSNHL. Patients and methods. Fifty patients with SSNHL were treated with systemic administration of steroids. Hearing recovery was determined by comparing the hearing levels before and after treatment. Tinnitus was subjectively evaluated by the tinnitus scoring questionnaire. The score for the five-step evaluation of the subjective tinnitus feelings ‘loudness’, ‘duration’ and ‘annoyance’ was obtained at the onset. Results. In terms of ‘duration’, when we divided all the cases into ‘tinnitus-rare’ group and ‘tinnitus-often’ group, HIR in the ‘tinnitus-rare’ group was significantly lower than that in ‘tinnitus-often’ group. When restricted to the ‘tinnitus-often’ group, HIR for ‘shorter duration’ was significantly higher than that for ‘longer duration’.

Horizontal canal type BPPV: bilaterally affected case treated with canal plugging and Lempert's maneuver.

A 54-year-old woman complained of positional vertigo. During 3 months’ observation, the patient showed mostly geotropic or apogeotropic nystagmus due to right canalolithiasis or cupulolithiasis, however, she sometimes showed nystagmus which suggested left horizontal canalolithiasis. We suspected that she suffered from bilateral horizontal canal type benign paroxysmal positional vertigo (BPPV) and performed Lempert’s maneuver for both directions, however, they were ineffective. She underwent canal plugging for right horizontal canal. After surgery she showed no positional nystagmus of right horizontal canal origin. However, apogeotropic nystagmus of the left horizontal canal origin was still observed. This nystagmus changed to geotropic nystagmus and finally disappeared following Lempert’s maneuver for the left side. Bilateral horizontal canal BPPV is difficult to be resolved, probably because physical treatment for one side would move debris to the cupula in the other canal. Canal plugging combined with Lempert’s maneuver to the other side is one treatment option for intractable bilateral horizontal canal BPPV.

Diagnosis of the subtype and affected ear of benign paroxysmal positional vertigo using a questionnaire

Abstract Conclusion: The prediction of subtype and the affected ear of benign paroxysmal positional vertigo (BPPV) derived from the answers to our questionnaire can support the definitive diagnosis of BPPV. Objectives: We examined to what extent the diagnosis of subtype and the affected ear of BPPV judged from answers to a questionnaire agreed with the diagnosis decided by the results of the positional nystagmus test. Methods: We asked the following questions: ‘What kind of head movements induce vertigo?’ and ‘How long does the vertigo continue?’. As for the affected ear, we asked which ear was lower during stronger vertigo when induced in a supine position or during sleep. Results: The percentages of correct diagnosis speculated by the combined answers were 69% in posterior canal-type BPPV, 48% in BPPV with geotropic nystagmus, and 39% in BPPV with apogeotropic nystagmus. The percentage of correct diagnoses of the affected ear was more than 80%.

Effects of cooling the pharyngeal mucosa after bipolar scissors tonsillectomy on postoperative pain

Abstract Conclusion: Bipolar scissors tonsillectomy followed by cooling down the pharyngeal mucosa has advantages in terms of postoperative pain and intraoperative blood loss compared with cold dissection. Objectives: The purpose of this study was to compare the postoperative pain between bipolar scissors tonsillectomy followed by cooling the pharyngeal mucosa and a traditional cold dissection. Methods: A total of 189 patients aged more than 16 years were operated due to habitual tonsillitis, obstructive sleep apnea syndrome, and IgA nephropathy. Of these, 79 patients were operated using bipolar scissors followed by cooling the pharyngeal mucosa with 4°C saline for 10 min just after the removal of tonsils. The other 110 patients underwent cold dissection tonsillectomy. Outcome measures were intraoperative blood loss, operative time, postoperative pain evaluated on a visual analog scale, and postoperative secondary hemorrhage. Results: Significantly lower levels of intraoperative blood loss and less postoperative pain were obtained in bipolar scissors tonsillectomy followed by cooling the pharyngeal mucosa compared with cold dissection. Postoperative hemorrhage needing hemostatic surgery occurred in 2 of 79 patients who underwent bipolar scissors tonsillectomy with cooling, while it occurred in 1 of 110 patients after cold dissection. However, the difference was not statistically significant.

Low-tone air-bone gaps after endolymphatic sac surgery

OBJECTIVES We detected chronic low-tone air-bone gaps (LTABGs) in some patients with Menieres disease after endolymphatic sac surgery. The aim of the present study was to elucidate the mechanism of LTABGs after endolymphatic sac surgery. METHODS We investigated 50 patients with Menieres disease, who underwent surgery more than two years prior. LTABGs were defined as the three-tone-average=20dB formulated by (a+b+c)/3, where a, b, and c are ABGs at 0.25, 0.5, and 1kHz, respectively (ABG ±). The intra-operative finding was focused on identifying operculum (OPC ±). RESULTS The ratio of post-operative ABG(+) was 50.0% (25/50). The ratio of intra-operative OPC(+) was 72.0% (36/50). The surgery results were as follows: the ratio of complete vertigo suppression (VS(+)) was 84.0% (42/50), air-conduction hearing gain (aHG(+)) was 40% (20/50), bone-conduction hearing gain (bHG(+)) was 64% (32/50), and speech discrimination gain (SDG(+)) was 28% (14/50). The post-operative ABG(+) was commonly observed in patients with intra-operative OPC(+) (chi-square test, p=0.013). aHG(+) and SDG(+) results were related to the post-operative ABG(+) (chi-square test, p=0.021 and p=0.0018, respectively). CONCLUSIONS These data suggest that intra-operative OPC(+) may be causative for post-operative ABG(+), resulting in post-operative aHG(+) and SDG(+). Thus, as enlarged vestibular aqueduct syndrome and superior semicircular canal deficiency syndrome exhibit LTABGs due to the third mobile inner ear window, endolymphatic sac surgery with adequate endolymphatic sac decompression and exposure to high doses of steroids, might induce LTABGs and the beneficial results of endolymphatic sac surgery.

P136: A Novel Therapy with Rho-kinase Inhibitor for SSHL:

Fasudil, a potent Rho-kinase inhibitor, has been reported to reverse the endothelin-induced vasoconstriction of spiral modiolar artery in the gerbil cochlea. We previously demonstrated that both endothelin receptors and endothelin converting enzymes were expressed in the rat cochlea and that serum endothelin of patients with sudden sensorineural hearing loss (SSHL) significantly increased before the steroid treatment. Since one subgroup of SSHL is believed to arise from vasoconstriction and vasospasm of the spiral modiolar artery which ultimately lead to ischemic stroke of the cochlea, we conducted clinical investigation of fasudil (Rhokinase inhibitor) combined with steroid for SSHL treatment to prevent the inner ear ischemia induced by endothelin. Nine out of ten SSHL patients (90%) who received intravenous infusion of fasudil (9 days x 30 mg x twice/day) with steroid showed complete or significant recovery as for the amount of hearing. The average hearing level was 72.7 dB (n=10) before the fasudil & steroid treatment, 44.9 dB at the end of the fasudil & steroid treatment (9 days after), and 31.9 dB at the final evaluation. The result indicates that idiopathic SSHL could be caused by vasoconstriction and vasospasm of the spiral modiolar artery in the cochlea by endothelin and that the fasudil & steroid therapy might be warranted as the novel potent treatment for SSHL.

A Case of Parotid Gland Oncocytoma

Oncocytoma is a rare tumor commonly found in the salivary gland. Here we report a case of oncocytoma arising in the parotid. Fine needle aspiration cytology revealed a moderate number of cell sheets of oncocyte-like cells, strongly suggesting oncocytoma, whereas neither CT scan nor MRI were informative. We believe that fine needle aspiration cytology is a useful diagnostic modality for oncocytoma.

[Audiological assessment of hearing-impaired children under age 3 and their later pure tone audiometry].

We analyzed the first audiological assessment and latest pure tone audiometry (PTA) in 29 hearing-impaired children (58 ears) visiting Osaka University for their first audiological assessment at the ages of 0, 1, and 2. We evaluated their hearing thresholds with PTA during follow-up and compared them to their first assessments. We combined auditory brain-stem response (ABR), behavioral audiometry, and conditioned orientation reflex (COR) for audiological evaluation of infants. Hearing thresholds assessed by 2 or 3 of these methods were sufficiently precise for hearing aid fitting. Thresholds of recorded ABR waves in 14 ears at loud sound pressure correlated well with later pure tone thresholds at high frequencies. Pure tone thresholds of those in whom no ABR waves were observed at 100 dB, were often out of scale at high frequencies--14% at 4000 Hz and 73% at 8000 Hz. Because of residual hearing at low frequencies, 4-frequency-averaged hearing at 500 Hz, 2 x 1000 Hz, 2000 Hz was better than 100 dB in 7 of 44 ears (16%), and 4 of 22 children (18%) did not fit the severest rank, 2, of the Disabled Persons, Welfare Law in Japan.