BACKGROUND/AIM: Sinonasal papilloma is a histologically benign tumor that demonstrates locally aggressive behavior, with a propensity for recurrence and potential for malignant transformation. This study aimed to evaluate the clinical characteristics, recurrence patterns, and malignant transformation of sinonasal papillomas and to propose appropriate follow-up strategies. PATIENTS AND METHODS: A retrospective analysis was conducted on 83 patients diagnosed with sinonasal papilloma at our institution. Clinical features, surgical treatments, recurrence intervals, and oncologic outcomes were analyzed. Tumors were staged using the Krouse classification for benign cases and UICC TNM staging for carcinoma-associated with papilloma cases. RESULTS: Among 83 patients (62 men, 21 women; median age 68), 74 (89.2%) were diagnosed as benign papillomas and nine (10.8%) as carcinoma-associated with papilloma. The recurrence rate among benign cases was 14.9% (11/74), with a median time to recurrence of 5 years and two months. Recurrence intervals exhibited a trimodal distribution: within two years (36.4%), between 2-10 years (36.4%), and after 10 years (27.3%). Malignant transformation occurred in one case (1.2%), and eight additional cases were found to be associated with carcinoma. Five of these were initially misdiagnosed as benign, underscoring the diagnostic limitations of imaging modalities. Krouse T3/T4 lesions were more frequently associated with recurrence and malignancy. Approximately 48.6% of patients discontinued follow-up, often before reaching the threshold for late recurrence. CONCLUSION: Sinonasal papillomas require long-term surveillance beyond five years due to their potential for late recurrence and malignant transformation. Preoperative suspicion of malignancy remains challenging, particularly in Krouse T3 lesions. Clinicians should consider extended follow-up, especially in patients with advanced tumor stage, and adopt a tailored surgical strategy to achieve complete resection. Patient education regarding recurrence risk is essential for optimizing long-term outcomes.

BACKGROUND/AIM: The oropharynx, hypopharynx, and esophagus share similar epithelial characteristics, rendering them highly susceptible to the development of synchronous or metachronous multiple primary cancers. As endoscopic technologies, including Narrow Band Imaging (NBI) and high-resolution imaging systems, have advanced, early-stage pharyngeal cancers are increasingly detected during routine endoscopic evaluations or follow-up examinations for other head and neck or esophageal malignancies. This study aimed to retrospectively evaluate the clinical features, treatment modalities, occurrence of synchronous/metachronous multiple primary cancers, and prognoses in patients with early-stage (Tis, T1, T2/N0) oropharyngeal and hypopharyngeal squamous cell carcinoma who underwent initial treatment between January 2016 and December 2021. PATIENTS AND METHODS: Seventy-six patients with early-stage oropharyngeal or hypopharyngeal squamous cell carcinoma were included in the analysis. Parameters evaluated included patient demographics, tumor classification and localization, detection methods, therapeutic interventions, presence and type of multiple primary cancers, and clinical outcomes. RESULTS: While the disease-specific survival (DSS) rates were generally favorable across T stages, overall survival (OS) rates were comparatively lower, with many deaths attributable to the progression of multiple primary cancers, especially those involving the upper gastrointestinal tract. Detection of Tis and T1 lesions often occurred incidentally during gastrointestinal endoscopy performed for other indications. In contrast, T2 lesions were predominantly detected following the onset of pharyngeal symptoms and ENT examination. Multiple primary cancers were highly prevalent, particularly esophageal and gastric carcinomas. CONCLUSION: Despite favorable DSS outcomes in early-stage oropharyngeal and hypopharyngeal cancers, OS remains compromised due to secondary malignancies. These findings underscore the critical need for early, isolated detection of pharyngeal carcinoma through interdepartmental collaboration, particularly with gastroenterologists and screening physicians, to enhance comprehensive cancer control and improve patient survival.

BACKGROUND/AIM: Immune checkpoint inhibitors (ICIs) have demonstrated clinical efficacy in recurrent and/or metastatic head and neck squamous cell carcinoma (R/M HNSCC). However, it remains a matter of debate which patient populations derive clinical benefit from salvage chemotherapy (SCT) following disease progression after ICI therapy. PATIENTS AND METHODS: This retrospective study included 97 patients with R/M HNSCC who received ICI therapy (nivolumab or pembrolizumab). Patients were classified into SCT (n=54) and non-SCT (n=43) groups after ICI failure. Survival outcomes, response rates, and clinical variables were compared between groups. RESULTS: The SCT group showed a significantly longer median overall survival (OS) compared to the non-SCT group (16.6 vs. 2.4 months, p<0.0001). These findings indicate that patients who received SCT had markedly better outcomes. Multivariate analysis identified SCT [hazard ratio (HR)=4.93, p<0.00001] and ECOG PS0,1 (HR=2.42, p=0.0257) as independent prognostic factors for OS. Patients treated with paclitaxel plus cetuximab (PTX + Cmab) had higher objective response rate (ORR) (50%) and disease control rate (DCR) (68.4%) compared to other regimens. CONCLUSION: SCT after ICI failure significantly improves survival in R/M HNSCC, particularly when using PTX+Cmab. Patients who received SCT had substantially better outcomes than those who did not. ECOG PS and sarcopenia status should be considered in treatment selection.

BACKGROUND/AIM: Poor nutritional status is one of the key contributing factors to sarcopenia, which negatively influences postoperative complications and clinical outcomes in patients with head and neck squamous cell carcinoma (HNSCC). This study aimed to investigate the potential association between sarcopenia and clinical outcomes in patients with recurrent and/or metastatic HNSCC treated with immune checkpoint inhibitors (ICIs). PATIENTS AND METHODS: A retrospective review was conducted on the medical records of 119 patients with recurrent and/or metastatic HNSCC who received ICI therapy. RESULTS: The objective response rates (ORRs) were 30.7% in the non-sarcopenia group and 15.8% in the sarcopenia group, showing a statistically significant difference between the two groups (p=0.048). Patients with good performance status (PS), absence of sarcopenia, and distant metastasis exhibited significantly longer overall survival (OS) compared to those with poor PS, sarcopenia, and locoregional recurrence, respectively (p=0.014, p=0.003, p=0.026). Multivariate analysis identified sarcopenia and locoregional recurrence as independent prognostic factors for OS. The incidence of immune-related adverse events (irAEs) did not significantly differ between patients with and without sarcopenia. CONCLUSION: These findings underscore the detrimental impact of sarcopenia on the efficacy of immune checkpoint inhibitor therapy in patients with recurrent and/or metastatic HNSCC. Careful consideration of sarcopenia is warranted in the clinical management of these patients.

Hearing starts, at the cellular level, with mechanoelectrical transduction by sensory hair cells. Sound information is then transmitted via afferent synaptic connections with auditory neurons. Frequency information is encoded by the location of hair cells along the cochlear duct. Loss of hair cells, synapses, or auditory neurons leads to permanent hearing loss in mammals. Birds, in contrast, regenerate auditory hair cells and functionally recover from hearing loss. Here, we characterized regeneration and reinnervation in sisomicin-deafened chickens and found that afferent neurons contact regenerated hair cells at the tips of basal projections. In contrast to development, synaptic specializations are established at these locations distant from the hair cells' bodies. The protrusions then contracted as regenerated hair cells matured and became functional 2 weeks post-deafening. We found that auditory thresholds recovered after 4-5 weeks. We interpret the regeneration-specific synaptic reestablishment as a location-preserving process that might be needed to maintain tonotopic fidelity.

Hearing loss is a chronic disease affecting millions of people worldwide, yet no restorative treatment options are available. Although non-mammalian species can regenerate their auditory sensory hair cells, mammals cannot. Birds retain facultative stem cells known as supporting cells that engage in proliferative regeneration when surrounding hair cells die. Here, we investigated gene expression changes in chicken supporting cells during auditory hair cell death. This identified a pathway involving the receptor F2RL1, HBEGF, EGFR, and ERK signaling. We propose a cascade starting with the proteolytic activation of F2RL1, followed by matrix-metalloprotease-mediated HBEGF shedding, and culminating in EGFR-mediated ERK signaling. Each component of this cascade is essential for supporting cell S-phase entry in vivo and is integral for hair cell regeneration. Furthermore, STAT3-phosphorylation converges with this signaling toward upregulation of transcription factors ATF3, FOSL2, and CREM. Our findings could provide a basis for designing treatments for hearing and balance disorders.

OBJECTIVES: To investigate the usefulness of harmonized 18F-FDG-PET/CT parameters for predicting the postoperative recurrence and prognosis of oral tongue squamous cell carcinoma (OTSCC). METHODS: We retrospectively analyzed the cases of 107 OTSCC patients who underwent surgical resection at four institutions in Japan in 2010-2016 and evaluated the harmonized PET parameters of the maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) for the primary tumor as the pSUVmax, pMTV, and pTLG. For lymph node metastasis, we used harmonized PET parameters of nodal-SUVmax, nodal-total MTV (tMTV), and nodal-total TLG (tTLG). The associations between the harmonized PET parameters and the patients' relapse-free survival (RFS) and overall survival (OS) were evaluated by the Kaplan-Meier method and Cox proportional hazard regression analysis for model 1 (preoperative stage) and model 2 (preoperative   +  postoperative stages). RESULTS: The harmonized SUVmax values were significantly lower than those before harmonization (p=0.012). The pSUVmax was revealed as a significant preoperative risk factor for RFS and OS. Nodal-SUVmax, nodal-tMTV, and nodal-tTLG were significant preoperative risk factors for OS. The combination of pSUVmax + nodal-SUVmax significantly stratified the patients into a low-risk group (pSUVmax <3.97 + nodal-SUVmax <2.85 or ≥2.85) and a high-risk group (pSUVmax ≥3.97 + nodal-SUVmax <2.85 or pSUVmax ≥3.97 + nodal-SUVmax ≥2.85) for recurrence and prognosis (RFS: p=0.001; OS: p<0.001). CONCLUSIONS: The harmonized pSUVmax is a significant prognostic factor for the survival of OTSCC patients. The combination of pSUVmax and nodal-SUVmax identified OTSCC patients at high risk for recurrence and poor prognosis at the preoperative stage.

BACKGROUND/AIM: Sarcopenia has an adverse effect on postoperative complications and prognoses in head and neck cancer. This study focused on hypopharyngeal and laryngeal cancer patients with sarcopenia and analyzed the body composition following treatment when the larynx was preserved and when total laryngectomy was performed to examine the usefulness of laryngectomy. PATIENTS AND METHODS: We retrospectively reviewed 88 primary hypopharyngeal and laryngeal cancer patients aged 65 years or older with cT2N0M0 or higher who visited our department. RESULTS: There were no significant differences in the 3-year overall survival rate and the 1-year local control rate between the laryngeal preservation group and laryngectomy group. The average change one year following treatment in the laryngeal preservation group, when compared to prior to treatment, was a significant decrease in the body weight (BW) of -0.035, skeletal muscle mass (SMM) of -0.030, skeletal muscle mass index (SMI) of -0.026, body mass index (BMI) of -0.034, and grip strength (GS) of -0.066. The average change one year following treatment in the laryngectomy group, compared with prior to treatment, was an increase in BW of +0.028, SMM of +0.026, SMI of +0.008, BMI of +0.032, and GS of +0.026. Although no changes in serum biochemical testing after treatment were observed in the laryngeal preservation group, albumin, transferrin, and transthyretin all exhibited significant improvement or a tendency toward improvement in the laryngectomy group. The patients with sarcopenia before treatment in the laryngeal preservation group had a significantly higher incidence of aspiration pneumonia. CONCLUSION: The presence or absence of sarcopenia before starting treatment is considered to be an index for selecting total laryngectomy.

Vestibular schwannoma (VS) is the most common tumor of the cerebellopontine angle. Despite the increasing diagnosis of sporadic VS over the past decade, the use of traditional microsurgeries to treat VS has decreased. This is likely a result of the adoption of serial imaging as the most common initial evaluation and treatment strategy, especially for small-sized VS. However, the pathobiology of VSs remains unclear, and elucidating the genetic information of tumor tissue may reveal novel insights. The present study performed a comprehensive genomic analysis of all exons in the key tumor suppressor and oncogenes from 10 small (<15 mm) sporadic VS samples. The evaluations identified NF2, SYNE1, IRS2, APC, CIC, SDHC, BRAF, NUMA1, EXT2, HRAS, BCL11B, MAGI1, RNF123, NLRP1, ASXL1, ADAMTS20, TAF1L, XPC, DDB2 and ETS1 as mutated genes. The current study could not draw any new conclusions about the relationship between VS-related hearing loss and gene mutations; however, it did reveal that NF2 was the most frequently mutated gene in small sporadic VS.

Coronavirus disease 2019 (COVID-19) occasionally causes acute laryngitis, requiring emergency treatment. Understanding the characteristic laryngeal findings can help diagnose COVID-19 earlier, prevent worsening infection, and properly manage airway obstruction. Herein, we report the case of a 44-year-old male with acute epiglottitis likely caused by COVID-19. On presentation, chest computed tomography (CT) showed no signs of pneumonia. However, the larynx had extensive necrotic-like erosive lesions resembling those of tuberculous laryngitis. COVID-19 was diagnosed by reverse-transcription polymerase chain reaction, and secondary bacterial superinfections were suspected after blood testing. The symptoms improved after administration of antibiotics (sulbactam sodium/ampicillin sodium), steroids (dexamethasone), and favipiravir. The patient developed a high fever on the sixth day of hospitalization, and pneumonia was identified on CT. Various culture tests, including tuberculosis, were negative. Thus, remdesivir was administered for COVID-19-induced pneumonia. The patient gradually recovered, was transferred to another hospital, and was discharged on the 35th day of hospitalization. Six previous case reports of COVID-19-induced acute epiglottitis suggested that acute epiglottitis preceded the onset of pneumonia. The laryngeal findings from this report may be useful for diagnosing COVID-19 that does not cause pneumonia and for bringing attention to pneumonia after a COVID-19 diagnosis.

症例1は25歳女性で、舌の異物感を主訴とした。舌根の正中やや左に境界明瞭で表面平滑な白色腫瘤を認め、CT画像では骨と同コントラストの腫瘤を認め、手術にて長径1.2cmの粘膜に覆われた腫瘤を摘出した。症例2は38歳男性で、舌の異物感を主訴とした。症例1と同様の腫瘤を舌根に認め、CTも同様の所見であり、手術にて長径1.1cmの粘膜に覆われた腫瘤を摘出した。2例とも病理組織所見で骨性分離腫と診断され、成熟した緻密骨組織のみを認めたことから鰓弓遺残によるものと考えられた。術後再発は認めていない。

OBJECTIVES: Hematoma in the retropharyngeal space (RPS) is a life-threatening condition that leads to rapid airway obstruction. However, the indication for airway management remains unclear. Additionally, the requirement for surgical hematoma evacuation remains undetermined. Therefore, we attempt to suggest some criteria for the management of hematoma in such cases. METHODS: We report three cases of hematoma in the RPS wherein one patient was treated without surgery and the other two underwent tracheotomy followed by hematoma evacuation. RESULTS: We found that airway management should be based on whether the glottis could be visible on laryngoscopy and dyspnea severity. The degree of hematoma, swelling, subcutaneous bleeding in the anterior neck, and emotional stability should also be considered. Proper management during the acute phase may allow for conservative treatments. Hematomas extending below the tracheal bifurcation may help ease upper airway obstruction due to pressure distribution, allowing for conservative treatment. When hematomas are surgically evacuated, tracheotomy should be performed simultaneously. Our report suggests that mediastinal hematoma evacuation could be avoided. CONCLUSION: We should determine a therapeutic strategy for hematoma in RPS based on glottis visualization, patient's condition, and extent of hematoma growth under careful observation.

Background: Malignant neoplasms (MNs) in the head and neck are occasionally hidden in deep neck infections (DNIs) that require emergency treatment, which potentially leads to delayed diagnosis of MNs.Objectives: This study aimed to identify predictive factors that can prevent delays in diagnosing MNs in patients with DNIs.Methods: We retrospectively analysed data from 83 patients admitted to our hospital who were diagnosed with DNIs.Results: Four patients (4.8%) had DNIs veiling MNs in the head and neck. Statistical analyses revealed a significant association (p = .0481) of platelet to albumin ratio (PAR; ≥ 98.9 × 103) with hidden MNs in DNIs. Furthermore, concomitant cervical lymphadenopathy, especially multiple lymphadenopathies and excluding abscesses, was higher in patients with DNIs veiling MNs (p = .0142 and p = .0023, respectively).Conclusions and Significance: The PAR, which can be easily measured and readily detected, was a potential predictive factor. Moreover, performing fine-needle aspiration for lymphadenopathies could help diagnose hidden MNs in DNIs.

BACKGROUND: In cholesteatoma, the prognosis of tympanoplasty has been well discussed in terms of hearing outcomes and residual or recurrent lesions. Postoperative dizziness and vertigo are major complications of tympanoplasty; however, few reports are available. AIMS/OBJECTIVES: We investigated each condition of cholesteatoma postoperative vestibular risk using the STAM system and staging published by EAONO/JOS, as well as findings on bony destruction. MATERIAL AND METHODS: From April 2010 to March 2021, 156 patients (166 ears) with cholesteatoma who underwent primary microscopic tympanoplasty at our hospital were registered. Subjective vestibular symptoms were recorded the day after surgery. RESULTS: Postoperative vestibular symptoms were observed in 13.9% of subjects. All of them were stage II and had both attic and mastoid lesions. Attic (p < .05) and mastoid (p < .01) lesions were risk factors. Multivariate analysis showed that significant differences were found in past histories of vestibular symptoms (p < .05) and exposure of the dura mater (p < .01). CONCLUSIONS AND SIGNIFICANCE: In the exposed dura group, the length of the prominence of the lateral semicircular canal to the middle cranial fossa dura was significantly shorter than that of the non-exposed group (p < .01). Narrow working space and downward operation may increase vestibular risk.

BACKGROUND: The advantage of up-front neck dissection (UFND) followed by chemoradiotherapy (CRT) for hypopharyngeal cancer (HPC) with advanced neck involvement remains controversial. We aimed to determine the indications. METHODS: The data of 41 and 14 patients with stage IVA/B (T1-T3 and ≥N2a) HPC who underwent UFND followed by CRT and received CRT, respectively, were retrospectively analyzed and compared. RESULTS: The 5-year overall survival (OS) and disease-specific survival rates for the UFND and CRT groups were 61% and 52% (p = 0.1019), and 89% and 74% (p = 0.2333), respectively. Moreover, patients aged ≥70 years or those with a pulmonary disease history had a significantly poorer prognosis due to aspiration pneumonia in the UFND group. The 5-year regional control (RC) for the UFND and CRT groups were 92% and 57%, respectively (p = 0.0001). CONCLUSIONS: UFND followed by CRT was feasible with satisfactory RC. To further improve OS, aspiration pneumonia prevention is essential.

症例は66歳男性で、早期食道癌合併咽頭癌T2N2bM0と診断し、先行頸部郭清術後セツキシマブによるbio-radiation therapy(BRT)を開始した。セツキシマブ6コース目終了後に粘膜炎がgrade 3となったため胃瘻栄養を併用し、セツキシマブ7コース目開始時点で胃瘻栄養のみとなったが放射線照射は完遂した。BRT終了後の喉頭内視鏡検査で腫瘍は消失していたが嚥下障害を認めた。BRT終了7ヵ月後の嚥下造影検査では造影剤が食道を通過せず、上部消化管内視鏡検査で梨状陥凹にピンホールのような間隙を認めたが内視鏡は通過しなかった。BRT終了1年5ヵ月後に胃瘻から逆行性に内視鏡を挿入して観察すると、胸部上部食道に易出血性の有茎腫瘍があり、口側の食道は高度に狭窄して内視鏡は通過しなかった。BRT終了1年6ヵ月後に下咽頭喉頭食道全摘出術および胃管再建術を施行し、術後経口摂取が可能となった。病理検査では組織の線維化が強い状態であった。

KEY POINTS: A highly positive potential of +80 mV in K+ -enriched endolymph in the mammalian cochlea accelerates sound-induced K+ entry into excitable sensory hair cells, a process that triggers hearing. This unique endolymphatic potential represents an EK -based battery for a non-excitable epithelial-like tissue, the stria vascularis. To examine whether and how the stria vascularis responds to sounds, we used our computational model, in which strial channels and transporters are serially connected to those hair cells into a closed-loop circuit, and found that mimicking hair cell excitation by acoustic stimuli resulted in increased extracellular [K+ ] and decreased the battery's potential within the stria. This observation was overall verified by electrophysiological experiments using live guinea pigs. The sensitivity of electrochemical properties of the stria to sounds indicates that this tissue is electrically coupled to hair cells by a radial ionic flow called a circulation current. ABSTRACT: Excitable cochlear hair cells convert mechanical energy of sounds into electrical signals necessary for neurotransmission. The key process is cellular depolarisation via K+ entry from K+ -enriched endolymph through hair cells' mechanosensitive channels. Positive 80 mV potential in endolymph accelerates the K+ entry, thereby sensitising hearing. This potential represents positive extracellular potential within the epithelial-like stria vascularis; the latter potential stems from K+ equilibrium potential (EK ) across the strial membrane. Extra- and intracellular [K+ ] determining EK are likely maintained by continuous unidirectional circulation of K+ through a putative K+ transport pathway containing hair cells and stria. Whether and how the non-excitable tissue stria vascularis responds to acoustic stimuli remains unclear. Therefore, we analysed a cochlear portion for the best frequency, 1 kHz, by theoretical and experimental approaches. We have previously developed a computational model that integrates ion channels and transporters in the stria and hair cells into a circuit and described a circulation current composed of K+ . Here, in this model, mimicking of hair cells' K+ flow induced by a 1 kHz sound modulated the circulation current and affected the strial ion transport mechanisms; the latter effect resulted in monotonically decreasing potential and increasing [K+ ] in the extracellular strial compartment. Similar results were obtained when the stria in acoustically stimulated animals was examined using microelectrodes detecting the potential and [K+ ]. Measured potential dynamics mirrored the EK change. Collectively, because stria vascularis is electrically coupled to hair cells by the circulation current in vivo too, the strial electrochemical properties respond to sounds. This article is protected by copyright. All rights reserved.

BACKGROUND: Furosemide-loading cervical vestibular-evoked myogenic potential (FVEMP), in which vestibular function is improved via diuretics-induced dehydration, can be used to estimate the presence of endolymphatic hydrops, one characteristic of Menière's disease. Inner ear magnetic resonance imaging (MRI) can also reveal endolymphatic hydrops.Aims/Objective: This study aimed to compare and confirm the usefulness of these two examination methods for the diagnosis of Menière's disease. METHODS: Twenty patients with definite unilateral Menière's disease were included. All subjects underwent both, FVEMP and inner ear MRI examinations. The results were then compared statistically between the affected and contralateral ears and among the methods. RESULTS: FVEMP and inner ear MRI of the cochlea, saccules, and utricles yielded positive results indicative of endolymphatic hydrops in 55.0%, 60.0%, 45.0%, and 45.0% of cases, respectively. The results of FVEMP were more consistent with those of the cochlea (κ = 0.8) than with those of the saccules or utricles by inner ear MRI (κ = 0.6). CONCLUSIONS: FVEMP appears to be a good and minimally invasive option for evaluating endolymphatic hydrops. However, the combination of FVEMP and inner ear MRI may yield even more accurate evaluations of endolymphatic hydrops.

他科から嚥下機能評価を依頼され、初回嚥下内視鏡検査を行った338例について検討した。対象は男220例、女118例、平均年齢72.4歳で、依頼科は呼吸器内科に次いで神経内科、脳神経外科が多かった。入院時の疾患は肺炎、悪性疾患の順に多く、依頼内容は全体の72%が「誤嚥なく経口摂取が可能か」であり、依頼科は嚥下障害の病因や病態ではなく経口摂取可否の判断を求めていた。評価後に肺炎をきたした症例は31例(9%)で、指示内容別では禁食・間接訓練12例(13%)、直接訓練可7例(23%)、形態制限経口摂取可10例(11%)などであった。本検討では日常生活動作などの評価の不十分さ、不顕性誤嚥や咀嚼嚥下の評価の不十分さが挙げられたほか、評価後に指示通りの対応ができているかを確認する体制や、状態に応じた対応のために再評価を行う体制の必要性が示された。

OBJECTIVE: To estimate the prevalence of potential electric-acoustic stimulation (EAS) implant candidates in a hearing-impaired population through a review of auditory examinations. METHODS: In total, 7356 patients underwent audiometric examination in our department between 2011 and 2014. The prevalence of patients meeting the audiometric criteria for EAS and standard cochlear implant (CI) was assessed. RESULTS: The percentage of EAS implant candidates meeting the pure-tone audiometric criteria was 0.71% (n=34) among the hearing-impaired individuals (n=4758) examined in our department, whereas 2.52% (n=120) met the criteria for standard CI. Among the 34 EAS implant candidates, 2 individuals (5.83%) received EAS implant surgery after approval of the EAS device in Japan. CONCLUSIONS: There was a lower prevalence of EAS implant candidates than standard CI candidates. Nevertheless, healthcare professionals should carefully examine the audiograms of patients with high frequency hearing loss with regard to meeting the indication criteria for EAS implant. This will enable patients to gain access to adequate information relating to further examinations and treatment options.

In this study, we report on a patient who had superior canal dehiscence and was treated by resurfacing the defect via the transmastoid approach. An 80-year-old male patient had the chief complaint of vertigo when he touched his left porus acusticus externus. As leftward nystagmus was induced by change in middle ear pressure and the existence of superior canal dehiscence was confirmed with computed tomographic scans (CT) of the temporal bones, we suspected an idiopathic labyrinthine fistula similar to the superior canal dehiscence syndrome (SCDS). At first, he was treated with medication, but as his vertigo was getting worse, he underwent surgery. A wide mastoidectomy was performed identifying the middle fossa dura. The superior semicircular canal was exposed together with the angle between the superior semicircular canal and the middle fossa bone. A bone pate was insinuated down the dehiscent canal. After the operation, no nystagmus was induced by change in the middle ear pressure and the patient did not feel any vertigo. When we anticipate the possibility of a transmastoid approach to a defect of superior canal based on preoperative CT findings, we should select this approach because the approach can avoid the more invasive middle fossa craniotomy.

まず、ChR2(光感受性非選択的陽イオンチャネル)が遺伝子改変マウスの蝸牛神経と坐骨神経の髄鞘に発現しているかを免疫組織化学実験により確かめた。電子顕微鏡を用いた詳細な解析(paranodeやjuxtaparanodeへの発現解析)までは行えなかったが、標的細胞への発現までは確認できた。中枢神経系の髄鞘の脱分極による神経刺激作用が報告されていることから、同様に末梢神経系でも生じ、それが神経再生の助長につながる可能性もあるという仮説をたて、in vivo実験を施行した。蝸牛神経の電気刺激応答は光刺激により、軽度ではあるが潜時の短縮が認められた。坐骨神経に対する同様の実験は現在検討中である。