Yamakawa first reported endolymphatic hydrops (EH) in a patient with Meniere’s disease (MD) in 1938. In the same year, Hallpike and Cairns also reported the association between MD and EH and established the modern diagnosis of MD. This association is now widely accepted; however, doubts have recently been raised. A recent human temporal bone study review failed to conclude if the association is an epiphenomenon or whether EH causes MD.

The mechanism of EH development remains enigmatically unclear. There is a large amount of evidence to suggest that water homeostasis in the inner ear is regulated partly via the vasopressin-aquaporin 2 (VP-AQP2) system, suggesting that EH reflects malregulation of the VP-AQP2 system in the inner ear fluid. Moreover, unfavorable development of the endolymphatic sac (ES) and duct and ES fibrosis have been reported in the temporal bones of MD patients. Based on these results, we hypothesized that a combination of ES dysfunction and dysregulation of endolymph might induce Meniere’s attacks.

Clinically, it is well known that Meniere’s attacks are related to stress. Moreover, the plasma level of VP, a stress hormone, is known to be increased in patients with MD. We recently developed an animal model that is better suited for studying MD, because this model consists of a combination of ES dysfunction and dysregulation of endolymph. In contrast to previous animal models that rarely showed episodes of imbalance, spontaneous nystagmus, or vertiginous attacks, even though they are distinct features of EH, they are evident in our model. Moreover, our model also shows hearing impairment.

In this paper, mechanisms underlying the formation of endolymphatic hydrops and its inner ear disorder the inner ear disorder associated with it are presented, mainly based on our recent studies.

A cavernous change due to otosclerosis that extends to the cochlear axis is called cochlear otosclerosis, which causes progressive sensorineural hearing loss (SNHL); cochlear implantation (CI) is considered in cases with severe to profound deafness. There are many reports of CI for adult cochlear otosclerosis, whereas this is only the second report of CI for a pediatric case of cochlear otosclerosis.

In this study, we report the case of an 11-year-old girl in whom we performed bilateral CI for SNHL due to cochlear otosclerosis. She had no problems during the perinatal period, and could speak some words by the age of 2. Gradually thereafter, however, she developed bilateral severe SNHL and became almost totally deaf by the age of 10. Temporal bone CT showed marked decalcification and osteogenesis of the otic capsules on both sides, suggesting that the left basal turns of the cochleas were narrow. The first CI (Cochlear, Contour, CI24RE (CA)) was performed on the right ear when she was 12 years old. Following the CI, improvement was noted not only in the pure tone hearing threshold, but also in speech perception. Five months later, the second CI on the left side was performed to achieve the better performance with bilateral CI. During the second CI, the intracochlear electrode array could not be fully inserted because of resistance when inserting the electrodes, and the postoperative results of CI on the left side were worse than those on the right side. However, at present, she is able to perform very well in her daily life with bilateral CIs, and plays important roles in society.

It was demonstrated that CI can be useful even for pediatric patients with cochlear otosclerosis. The indications for CI in these children must be carefully considered by evaluating the results of imaging examinations, such as CT, and provision of adequate explanation prior to the procedure is considered as very important.

We report a case of bilateral cochlear implant surgery performed for profound sensorineural hearing loss in a 2-year-old girl with Wolfram syndrome and osteogenesis imperfecta type I. Wolfram syndrome is a rare autosomal-recessive genetic disorder characterized by juvenile diabetes mellitus and visual impairment. The hearing loss in Wolfram syndrome is typically a slowly progressive sensorineural hearing loss, primarily in the high-frequency range. Genetic testing of our patient showed mutations in WFS1 and COL1A1. Bilateral cochlear implant surgery was performed, because adequate wearing thresholds could not be achieved with hearing aids. This report is the first case of a patient with Wolfram syndrome with profound congenital hearing loss who benefited from cochlear implant surgery. The patient had a visual-auditory dual disability and lacked external stimuli. The cochlear implant provided valuable auditory compensation to ensure auditory stimulation. In the future, it is necessary to continue comprehensive rehabilitation for the patient with collaboration among the parents, speech-language pathologists, and rehabilitation facilities.

Peripheral facial nerve palsy is a common disease encountered by otolaryngologists, but rarely occurs in both sides at the same time. Causative diseases include Bell’s palsy, Guillain-Barre syndrome, trauma, otitis media, Ramsay Hunt syndrome, sarcoidosis, etc. During the past 10 years, a total of 528 patients with facial nerve palsy visited our department, and only 2 (0.4%) had simultaneous bilateral palsy.

The first patient was a 70-year-old man who presented with a 1-day history of drooling and difficulty in articulating bilabials. The following day, he developed impaired closure of his eyes. He showed bilateral severe facial nerve palsy without other neurological disorders. Brain CT/MRI, cerebrospinal fluid examination, and ⁶⁷Ga-scintigram showed no abnormalities. Serology for IgM antibody against herpes simplex/varicella-zoster viruses was negative. Under a diagnosis of bilateral Bell’s palsy, the patient received antiviral drug and high-dose steroid, and completely recovered by the 61st day from onset.

The second patient was a 73-year-old woman with a past history of malignant melanoma of the rectum. She presented with an 11-day history of left-sided severe facial palsy. She was initiated on treatment with an antiviral drug and high-dose steroid on the 13th day from onset, but the following day, she manifested facial palsy of the contralateral side. She subsequently developed hemifacial hypesthesia, diplopia, and hoarseness. Brain MRI revealed multiple mass lesions in the cerebrospinal space, including the bilateral cerebellopontine angles and internal acoustic meatus. The patient was diagnosed as having leptomeningeal dissemination of metastatic malignant melanoma and treated with nivolumab and ipilimumab; however, she died of the cancer progression on the 64th day from the onset of the first facial palsy.

It is important to be aware of the difficulties in evaluating the severity of palsy and the importance of thorough systemic examinations to search for latent causes in patients with bilateral simultaneous facial nerve palsy.

External auditory canal cholesteatoma (EACC) is a condition characterized by periostitis of the bone of the external auditory canal. EACC is usually treated conservatively, however, some patients need surgical intervention because of invasion of adjacent structures. We examined the clinical features and surgical procedures used for treatment in 12 patients with EACC who were treated by surgery at our institution. Two patients were classified as stage III and 10 cases as stage IV, accordind to Naims’classification. Eleven cases of patients had primaly EACC, while one was a recurrent case. Six patients underwent canalplasty via a postauricular incision, one patient underwent canalplasty with tympanoplasty, two patients underwent canal wall up tympanoplasty, and three patients underwent canal wall down mastoidectomy. There were no cases of recurrence, although the follow-up period was not sufficiently long in some cases. In order to determine the extent of the cholesteatoma to select the appropriate operative procedure, preoperative CT is crucial. During the operation, it is important to drill pathological bone and smoothen the bony external auditory canal.

We treated 10 cases of chronic rhinosinusitis with nasal polyps (CRSwNP) with dupilumab, an anti-IL-4/IL-13 antibody receptor drug, and examined the longitudinal changes in the levels of type 2 inflammatory markers, such as the fraction of exhaled nitric oxide (FeNO), blood eosinophil count, and serum total IgE before and after 24 weeks of dupilumab administration.

Although the FeNO decreased significantly after 24 weeks of treatment with dupilumab as compared with that before treatment, it was considered that the result reflected type 2 inflammation of the lower respiratory tract, and not directly the condition of the CRSwNP. The blood eosinophil count increased after 24 weeks of treatment, and tended to be lower in the 5 patients who received mepolizumab prior to dupilumab as compared with the 5 patients who did not receive mepolizumab. Significant decrease of the serum total IgE was observed after 24 weeks of treatment with dupilumab as compared with the level recorded prior to treatment. IL-4 receptor alpha chain gene abnormality has been shown to be associated with the serum total IgE level, and serum total IgE may be one of the indicators reflecting the effect of dupilumab on IL-4R alpha. It is a commonly performed test and a larger number of cases needs to be examined.

Endoscopic laryngopharyngeal surgery (ELPS) is a minimally invasive therapy, in which superficial lesions are resected directly with the assistance of a laryngoscope.

On the other hand, ELPS is difficult to perform in several cases of hypopharyngeal cancer because of previous therapies, including radiotherapy and/or chemotherapy. Unfortunately, such cases require total laryngopharyngectomy with cervical esophagectomy for radical cure.

Herein, we report two cases of cancer of the hypopharynx in whom we performed ELPS after chemotherapy. The first patient had received chemotherapy (taxotere, cisplatin,5-fluorouracil) for co-existing esophageal cancer. After 2 cycles of this chemotherapy, the hypopharyngeal tumor almost disappeared endoscopically and was resected by ELPS. The other patient had previously received radiation therapy for malignant lymphoma (mantle irradiation) and developed hypopharyngeal carcinoma involving the cervical esophagus. Because the patient did not wish to have a major operation, we selected chemotherapy (cisplatin,5-fluorouracil, cetuximab). After 4-cycles of this chemotherapy, the tumor decreased in size, and we performed ELPS. The laryngeal function is well-preserved in both cases, and neither case has shown recurrence.

It appears that the combination of induction chemotherapy and ELPS is useful for the treatment of hypopharyngeal cancer with preservation of the laryngeal function.

We encountered a case with a very small metallic foreign body inside the parapharyngeal space which was removed via the transoral approach.

The patient was 36-year-old man living on a remote island. He visited the island’s clinic with a sore throat that he developed after eating fish soup. But his symptoms disappeared soon thereafter. However, the throat pain recurred after two months, and CT revealed a small foreign body inside the parapharyngeal space; the patient was immediately referred to our institution for removal of the foreign body. Since there was no abscess observed on the overlying skin and the location of the foreign body inside the parapharyngeal space could be well identified on the CT images, we attempted to remove it via a transoral approach without incising the skin. Intraoperative radiography and ultrasound were very useful to identify and remove the foreign body. However, the navigation system that we frequently use for operations of the nasal-paranasal sinuses was not as useful as we thought in this case.

The transoral approach is less invasive for the patient. If there is no inflammation or abscess in the affected area and the target foreign body can be identified before or during the operation, this approach may be of some advantage over the external incision method.

Lipomas in the head and neck region account for about 10% of all lipomas, but they are most often subcutaneous and are rarely located in the laryngeal cavity. Spindle cell lipoma (SCL) is a rare special type of lipoma. Herein, we report a case of pedunculated SCL of in the larynx.

A 52-year-old man detected to have a pedunculated mass in the upper esophagus visited our University hospital. The mass lesion had been detected several years earlier by upper gastrointestinal endoscopy, but the patient had no clinical symptoms. The mass lesion could not usually be seen by fiberoptic laryngoscopy. When the pharyngeal reflex was activated, the tip of the pedunculated mass was expelled into the pharyngeal cavity, and the base of the mass was confirmed in the left arytenoid region. The pedunculated mass was resected by transoral videolaryngoscopic surgery, and histological examination of the resected specimen revealed the diagnosis of SCL.

As recurrences and malignant transformation have been reported in cases of SCL, our patient remains under close follow-up.

It is difficult to treat laryngeal vascular malformations because of airway problems, bleeding, etc. A variety of treatments have also been described, including direct laryngoscopic excision, excision through an external incision, laser surgery, and sclerotherapy. As important goals of treatment, preservation of the laryngeal functions, such as voice and swallowing functions is important, as this condition is a benign one.

We report a case of laryngeal capillary malformation in which transoral surgery was performed after sclerotherapy, and a good outcome was obtained.

The patient was a man in his 30s, who presented to his neighborhood otorhinolaryngologist with a history of pharyngeal discomfort; he was found to have a laryngeal mass and referred to our hospital, and we diagnosed him as having a laryngeal vascular malformation. After tracheotomy under local anesthesia, we performed sclerotherapy twice by injecting monoethanolamine, and resected the lesion by transoral surgery. One year seven months after the surgery, the patient’s voice and swallowing functions remain good, and there has been no evidence of lesion recurrence.

Sclerotherapy is a relatively easy procedure and effective in the treatment of vascular malformations. Although sclerotherapy alone does not result in sufficient tumor regression in cases with large lesions, it should be the treatment modality of first choice, as it can reduce intraoperative bleeding and facilitate surgery by shrinking the lesion. For relatively large lesions, as in the present case, we consider it effective to first administer sclerotherapy, and then perform transoral resection surgery.

Thyroidectomy by video assisted neck surgery (VANS) is associated with an elevated risk of recurrent laryngeal nerve injury, especially in the presence of unexpected anatomical abnormalities, such as non-recurrent inferior laryngeal nerve (NRILN), which can be exceedingly difficult to identify and preserve. To reduce the risk of nerve damage, computed tomography (CT) and ultrasonography are useful for preoperative diagnosis, but the number of cases in which anatomical abnormalities can be diagnosed by these modalities is limited. At our department, intraoperative neuromonitoring is performed during all thyroid surgeries, including VANS, in an attempt to reduce the risk of nerve injury.

In this article, we present the case of a 66-year-old female patient in whom intraoperative nerve monitoring during VANS identified a NRILN, which was difficult to diagnose preoperatively, and nerve injury was prevented. The patient was initially started on antithyroid medication to treat Graves’ disease, but the medication had to be discontinued after 2 weeks due to the occurrence of adverse events such as fever, skin rash and liver damage. Therefore, total thyroidectomy was performed by VANS for radical cure. Plain CT and ultrasonography were performed preoperatively, but no anatomical abnormalities could be detected. However, we were able to confirm and preserve a NRILN by intraoperative neuromonitoring using a 4-step procedure to identify the recurrent laryngeal nerve after confirming the vagus nerve. No vocal cord paralysis was observed postoperatively.

Intraoperative neuromonitoring may reduce the risk of unintentional injury of a NRILN during thyroid surgery, including VANS. Therefore, adherence to the 4-step procedure is crucial for identifying and preserving the recurrent laryngeal nerve.

Retropharyngeal hematoma is an uncommonly encountered condition. However, early diagnosis and appropriate treatment are important owing to the risk of upper airway obstruction. We report a case of retropharyngeal hematoma that needed surgical drainage. A 73-year-old man receiving anticoagulant therapy sustained injury when he fell to the ground on his face. Cervical CT and MRI showed a retropharyngeal hematoma extending from the retropharyngeal to the superior mediastinal space. Flexible fiberoptic laryngoscopy revealed no airway obstruction. However, on day 10 after the injury, the hematoma was found to have increased in size; although there was no dyspnea at the time, owing to the imminent risk of airway obstruction, we performed surgical drainage of the hematoma with no tracheostomy. We reviewed 43 articles on retropharyngeal hematoma reported in the literature to elucidate the clinical characteristics, treatment, and outcomes of this condition. More than a half of the cases published in these reports received conservative treatment; however, about 30% of the cases eventually required tracheostomy because of airway obstruction.

This case report underscores the need to bear in mind the possibility of delayed airway obstruction developing after an asymptomatic interval in patients with retropharyngeal hematoma.

There are many cases of foreign bodies in the hypopharynx or esophagus that are removed using a flexible fiberoptic upper gastrointestinal endoscope, however, there are also cases in which, due to the shape and size of the foreign body and/or the anatomical problems, it is difficult to remove foreign bodies using a flexible fiberoptic endoscope. Conventional rigid esophagoscopy can sometimes be difficult due to the problem of a narrow visual field. In these case, the Sato rigid curved laryngoscope strongly lifts the larynx and provides a wide field of view and space at the entrance of the esophagus from the hypopharynx.

Herein, we report three cases in which removal of a foreign body could be safely performed using the Sato rigid curved laryngoscope under general anesthesia.

The Sato rigid curved laryngoscope is a useful device to safely observe and remove foreign bodies, as a large working space can be secured due to expansion of the lumen of the hypopharynx and cervical esophagus.

Various factors cause deep neck abscesses. Severe cases can develop the complication of internal jugular vein thrombosis. Acute suppurative thyroiditis is one of the most common causes of deep neck abscess. Most cases arise from a hypopharyngeal pyriform sinus fistula, and the abscess is often on the left side of the neck. We report a case of acute suppurative thyroiditis developing from the right lobe of the thyroid that was complicated by internal jugular vein thrombosis.

A 44-year-old male patient received antibacterial therapy for sore throat, but showed no improvement. He developed swelling and pain in the right anterior neck. He was diagnosed as having subacute thyroiditis at another hospital and treated with steroids. However, his symptoms worsened, and he was referred to our hospital. Ultrasonography and computed tomography (CT) showed an abscess extending outward from the right lobe of the thyroid gland, and an incision was made to drain the pus. We did not find a fistula in the hypopharyngeal pyriform sinus. Culture of the abscess fluid grew Micromonas micros, Fusobacterium nucleatum, and Porphyromonas gingivalis. There were no infected lesions in the teeth or oropharynx. Based on the findings, the patient was suspected as having acute suppurative thyroiditis due to the infection of a hypopharyngeal pyriform sinus fistula. The CT showed a thrombus in the right internal jugular vein, and the patient received anticoagulant therapy for one year. However, the thrombus failed to resolve.

Acute suppurative thyroiditis and subacute thyroiditis are difficult to differentiate based the symptoms and blood test results alone. When abscess formation is suspected based on the imaging diagnosis, we suggest performing surgical procedures, such as puncture and incision.