Vestibular compensation: Neural mechanisms and clinical implications for the treatment of vertigo

After unilateral peripheral vestibular lesions, the neural activity of neurons in the ipsi-lesional medial vestibular nucleus (ipsi-MVe) are markedly decreased, resulting in static and dynamic asymmetries of the vestibulo-ocular and vestibulo-spinal reflexes. Consequently, static vestibular symptoms such as spontaneous nystagmus and postural deviation and dynamic vestibular symptoms such as oscillopsia and swaying gait are induced. However, these behavioral asymmetries gradually recover after the lesion. Progressive balance restoration is termed vestibular compensation, which is divided into two phases: static and dynamic. Static vestibular compensation is further divided into initial and late processes. In the initial process of static vestibular compensation after unilateral labyrinthectomy (UL) in rats, plastic changes in the cerebello-vestibular and vestibular commissural inhibitory pathways suppress neurons in the contra-lesional MVe (contra-MVe), resulting in the restoration of symmetrical resting activity of MVe neurons on both sides at low levels. The declining frequency of spontaneous nystagmus after UL is an index of the initial process, and short-term administration of diazepam, a GABAA receptor agonist, has been shown to accelerate the initial process in rats. Accordingly, short-term administration of diazepam is recommended for the treatment of acute vertigo in patients with unilateral vestibular dysfunction. In the late process of static vestibular compensation after UL in rats, the resting activity of ipsi-MVe neurons gradually recovers due to changes in cell membrane properties, resulting in the reinforcement of balanced intervestibular nuclear activities to nearly normal levels without the suppression of contra-MVe neurons. The declining number of MK801-induced Fos-positive neurons in contra-MVe after UL is an index of the late process, and long-term administration of betahistine, a histamine H3 receptor antagonist, has been shown to accelerate the late process in rats. Accordingly, long-term administration of betahistine is recommended for the treatment of subacute vertigo in patients who were not compensated for unilateral vestibular dysfunction. In the process of dynamic vestibular compensation after UL, the sensitivity of ipsi-MVe neurons to head velocity and acceleration is restored due to synaptic changes such as long-term potentiation and sprouting of commissures, resulting in the restoration of the dynamic vestibulo-ocular and vestibulo-spinal reflexes. To facilitate dynamic vestibular compensation, early ambulation and subsequent vestibular rehabilitation exercise are recommended for the treatment of chronic vertigo in patients with uncompensated unilateral vestibular dysfunction. Although vestibular compensation after bilateral vestibular loss is not expected, vestibular rehabilitation with a sensory-substitution strategy can improve imbalance in patients with bilateral vestibular lesions.

Effects of high-dose betahistine on intractable dizziness in patients with uncompensated unilateral vestibulopathy

OBJECTIVE

In the present study, we examined the effects of high-dose betahistine on dizziness handicap inventory (DHI) scores in patients with unilateral vestibulopathy.

METHODS

An uncontrolled, open-label, multicenter clinical trial was conducted. Fifteen patients with unilateral vestibulopathy, such as vestibular neuritis, who complained of intractable dizziness for more than three months were enrolled. Initially, all patients were orally administered betahistine at a dose of 36 mg/day for four weeks, which is the standard dose and dosing period for the treatment of dizziness in Japan. The patients were then administered betahistine at a double dose of 72 mg/day for four weeks. Six patients who became aware of the benefits of high-dose betahistine were further administered betahistine at 72 mg/day for an additional 12 weeks (a total of 16 weeks). Perceived disability due to dizziness was assessed by DHI scores.

RESULTS

In all 15 patients, short-term administration with high-dose (72 mg/day) betahistine for four weeks, but not low-dose betahistine (36 mg/day) for four weeks significantly decreased DHI scores. In particular, in six responding patients with self-reported benefits after short-term administration with high-dose betahistine, long-term administration with high-dose betahistine for 16 weeks further significantly decreased DHI scores. However, DHI scores of the remaining nine non-responding patients were not changed after short-term administration with high-dose betahistine for four weeks.

CONCLUSION

Short-term administration with the standard dose and dosing period of betahistine did not improve DHI scores in the enrolled patients, indicating that they were not compensated for unilateral vestibulopathy with intractable dizziness. The present findings suggest that long-term administration with high-dose betahistine facilitates vestibular compensation to improve intractable dizziness in some, but not all patients with uncompensated unilateral vestibulopathy.

Differences in semicircular canal function in the video head impulse test in patients in the chronic stage of sudden sensorineural hearing loss with vertigo and vestibular neuritis

BACKGROUND

Sudden sensorineural hearing loss with vertigo (SHLV) and vestibular neuritis (VN) can result in prolonged dizziness.

OBJECTIVES

This study aimed to compare the video head impulse test (vHIT) of patients with SHLV and VN.

METHODS

Fifteen patients with SHLV and 21 patients with VN who visited the Vertigo/Dizziness Center of our hospital between December 2016 and February 2023 were included. vHIT was performed at the time of admission, and the VOR gain and catch up saccade (CUS) in the three types of semicircular canals (SCCs) were analyzed.

RESULTS

Pathologic vHIT results were observed most frequently in the posterior SCC (73%), followed by lateral (53%) and anterior (13%) SCCs in the SHLV group. In contrast, pathologic vHIT results were observed most frequently in the lateral SCC (100%), followed by the anterior (43%) and posterior SCC (24%) SCCs in the VN group. Pathological vHIT results in the lateral and posterior SCC showed significant differences between the two groups, but for anterior SCC, no significant differences were found.

CONCLUSIONS AND SIGNIFICANCE

Comparison of the two vHIT results revealed differences in the SCC dysfunction patterns. This may be due to the different pathophysiological mechanisms of the two vestibular disorders, which may result in prolonged vertigo.

Reviewing Kampo medicine (Traditional Japanese Herbal Medicine) for otology/neurotology diseases

Kampo medicine, a traditional Japanese herbal medicine, is used for the treatment of otologic and neurotologic diseases in Japan and other Asian countries. However, only Japanese medical doctors can prescribe both Kampo and modern (Western) medicine. Since a medical doctor can perform not only the diagnosis but also Kampo treatment, it is expected that the quality of clinical studies on traditional herbal medicine is higher in Japan than that in other countries. However, there is no Kampo review written in English language for the treatment of otology/neurotology diseases. Herein, we would like to demonstrate evidence of Kampo treatment for otology/neurotology diseases according to previous studies in Japan.

Frailty of the

Vestibular frailty and presbyvestibulopathy, including benign paroxysmal positional vertigo (BPPV), can cause dizziness among elderly patients. Vestibular frailty and presbyvestibulopathy may contribute to the onset of the vicious circle of falling-bone fracture-prolonged bedridden status-senile dementia. Treatment interventions for vestibular frailty and presbyvestibulopathy should be based on vestibular rehabilitation rather than vestibular implantation or regeneration. In acute BPPV, the otolith repositioning maneuver can be used to return otolithic debris to the utricle. At the chronic remission stage, there are nutritional guidelines for improving bone density in otolith organs and rehabilitation guidelines for activating otolith organs to prevent exfoliation. Moreover, sleeping in the head-up position can prevent free-floating debris from entering the semicircular canal. Throughout their old age, the psychiatric care/support is also indispensable to keep their initiative against vestibular frailty.

Relationship between stress levels and endolymphatic space volume in Meniere's disease

OBJECTIVES

Since the first report by Hallpike and Yamakawa in 1938, many more patients with Meniere's disease (MD) with endolymphatic hydrops (EHs) have been described. Mental/physical stress and a subsequent increase in the release of the anti-diuretic hormone (ADH) supposedly triggers MD. In the present study, to assess the relationship between stress and EHs, we conducted a series of stress-related questionnaires as well as a 3D endolymphatic space (ELS) analysis in patients with unilateral MD.

METHODS

We enrolled 76 patients with unilateral MD (uMD) as the active group and 75 patients with unilateral benign paroxysmal positional vertigo (uBPPV) as the control group; both underwent examinations between June 2014 and November 2019. All patients underwent 3-T magnetic resonance imaging (MRI) 4 h after intravenous gadolinium injection. We used the total fluid space (TFS), ELS, and ELS rate (ELS/TFS × 100), which is the percentage of the volume of the ELS relative to that of the TFS, for a precise evaluation of the ELS and EHs in MD. Stress was evaluated using the Self-Rating Depression Scale (SDS), the psychological Stress Response Scale (SRS), and the modified Dizziness Handicap Inventory (mDHI). Stress scores and blood ADH levels were compared across patient groups.

RESULTS

In patients with uMD, ELS rates significantly correlated with SRS scores on both the affected and the healthy side and with mDHI scores on the affected side, while the SDS and ADH showed no significant correlation with the ELS rates. Correlations were much stronger in the group with severe SDS and one with low ADH levels.

CONCLUSIONS

The present results indicate that stress may be involved in EHs development in uMD, not only in the ipsilateral but also the contralateral ear. They also suggest that patients with neuropsychiatric tendencies may develop EHs and MD in response to a stressful lifestyle.

The effects of continuous administration of diazepam on the recovery of lesion-induced nystagmus in unilaterally labyrinthectomised rats

BACKGROUND

Diazepam, a gamma-aminobutyric acid type A receptor agonist, is classified as a vestibular suppressant and is effective in treating acute vertigo. However, its effects on vestibular compensation (VC) remain unclear.

OBJECTIVES

We examined the effects of continuous administration of diazepam on the frequency of spontaneous nystagmus (SN) after unilateral labyrinthectomy (UL) as an index of the initial process of VC in rats.

MATERIALS AND METHODS

Diazepam was continuously administered at doses of 3.5 and 7.0 mg/kg/day, intraperitoneally, via an osmotic minipump. The frequency of SN beating against the lesion side after UL was measured. Potassium chloride (KCl) solution (1 M) was injected intratympanically to induce SN beating to the injection side.

RESULTS

Continuous administration of diazepam significantly and dose-dependently decreased the frequency of SN after UL, and also reduced the x intercept of the nonlinear regression curve of the decline in UL-induced SN with time in rats. However, the continuous administration of diazepam did not affect the frequency of intratympanic KCl-induced SN in the rats.

CONCLUSION

These findings suggested that continuous administration of diazepam accelerates the initial process of VC; however, it does not suppress the nystagmus-driving mechanisms in rats.

Volume ratio and distribution rate in patients with orthostatic vertigo/dizziness using MR imaging: a comparison with vertiginous diseases

BACKGROUND

Orthostatic dizziness/vertigo (ODV) is characterized by lightheadedness owing to postural changes.

AIMS/OBJECTIVES

To measure the endolymphatic space (ELS)/total fluid space (TFS) volume ratio and the distribution rate of endolymphatic fluid (ELF) of patients with ODV and compare them with those of control subjects (CS).

MATERIALS AND METHODS

This study included 22 patients (44 ears) with ODV and 52 controls (104 ears, CS). The ELS/TFS volume ratio (%) and distribution rate (%) of the inner ear components were measured using 3-dimensional magnetic resonance imaging.

RESULTS

In the ODV group, the mean ELS/TFS volume ratios of the cochlea, vestibule, and semi-circular canals (SCCs) were 12.1%, 18.6%, and 18.1%, respectively; the mean ELS distribution rates for the cochlea, vestibule, and SCCs were 27.3%, 26.2%, and 46.6%, respectively. The ELS distribution rate of the vestibule was significantly lower (p < .01) and the ELS distribution rate of the SCCs was significantly higher in the ODV than in the CS group (p < .01).

CONCLUSIONS AND SIGNIFICANCE

The ELS distribution rate in the vestibule + SCCs among patients with ODV did not differ from that in the CS; ELF in the vestibule moved to the SCCs, and a large amount of ELF was distributed only in the SCCs.

Cartilage Conduction Hearing Aids in Clinical Practice

A relatively loud sound is audible when a vibrator is attached to the aural cartilage. This form of conduction is referred to as cartilage conduction (CC). In Japan, a new type of hearing aid has been developed using CC and has been available in clinical practice since 2017. A clinical study conducted prior to its launch demonstrated its benefits, particularly in patients with aural atresia who were unable to use air conduction hearing aids. Several studies have been published on the benefits of CC hearing aids since their introduction into clinical practice. Most of the patients included in these studies had canal stenosis or aural atresia, and the purchase rates of CC hearing aids in these patients were relatively high. However, the number of patients with canal-open ears was small, with overall poor results in the trials, with the exception of patients with continuous otorrhea. CC hearing aids are considered a good option for compensating for hearing loss in ears with canal stenosis or atresia in both bilateral and unilateral cases. However, CC hearing aids are not currently considered the first choice for patients with a canal-open ear.

Evaluation of usefulness of tongue pressure measurement device for dysphagia associated with treatment of patients with head and neck cancer (ELEVATE)

INTRODUCTION

Dysphagia is often caused by radiotherapy (RT) in patients with head and neck cancer (HNC), and reduced tongue pressure (TP) is often associated with swallowing dysfunction in the oral stage. However, the evaluation of dysphagia by measuring TP has not yet been established in HNC patients. Herein, we conducted a clinical trial to evaluate the usefulness of TP measurement using a TP-measuring device as an objective indicator of dysphagia induced by RT in HNC patients.

METHODS AND ANALYSIS

This ELEVATE trial is a prospective, single-center, single-arm, non-blind, non-randomized trial to evaluate the usefulness of a TP measurement device for dysphagia associated with the treatment of HNC. Eligible participants include patients with oropharyngeal or hypopharyngeal cancer (HPC) undergoing RT or chemoradiotherapy (CRT). The TP measurements are conducted before, during, and after RT. The primary endpoint is the change in the maximum TP values from before RT to 3 months after RT. Moreover, as secondary endpoints, the correlation between the maximum TP value and the findings of video-endoscopic and video-fluoroscopic examinations of swallowing will be analyzed at each evaluation point, as well as changes in the maximum TP value from before RT to during RT and at 0, 1, and 6 months after RT.

DISCUSSION

This trial aimed to investigate the usefulness of evaluation by measuring TP for dysphagia associated with HNC treatment. We expect that an easier evaluation for dysphagia will improve rehabilitation programs for dysphagia. Overall, we expect this trial to contribute to the improvement of patients' quality of life (QOL).

Type I Thyroplasty or Fat Injection Laryngoplasty Versus Arytenoid Adduction: Effects of Surgery on Voice Recovery in Patients With Unilateral Vocal Fold Paralysis

Objective: Type I (medialization) thyroplasty (MT), fat injection laryngoplasty (FIL), and arytenoid adduction (AA) are the 3 most common surgical treatments for unilateral vocal fold paralysis (UVFP). While MT and FIL involve medialization of the paralyzed vocal fold, the goal of AA is to reduce the glottal-level difference. The current study compared the effects of these surgical treatments on voice quality in patients with UVFP. Methods: This retrospective study included 87 patients with UVFP who underwent MT (n = 12), FIL (n = 31), AA (n = 6), or AA with MT (n = 38). Patients who underwent the former 2 surgical treatments were included in the thyroplasty (TP) group, while those who underwent the latter 2 were included in the AA group. Maximum phonation time (MPT), pitch period perturbation quotient (PPQ), amplitude perturbation quotient, and harmonic-to-noise ratio (HNR) were evaluated in all patients before and 1 month after surgery. Results: The TP group exhibited significant improvements in MPT (P < .001) and PPQ (P = .012), while the AA group exhibited significant improvements in all parameters (P < .001). Before surgery, voice quality was significantly worse in the AA group than in the TP group for all measures. However, there were no significant differences between the groups after treatment. Conclusion: Surgeries in both groups were effective for voice recovery in patients with UVFP under the appropriate surgical selection. Our results also highlight the importance of preoperative evaluation and the potential value of etiology for selecting the appropriate procedure.

Evaluation of changes in endolymphatic volume after middle ear pressure therapy for intractable meniere's disease using 3D magnetic resonance imaging

BACKGROUND

Nowadays, the endolymphatic space size can be evaluated by 3D-analysis of 3 T-MRI after intravenous injection of gadolinium enhancement.

AIMS/OBJECTIVES

In the present study, to elucidate the relationships between vertigo and endolymphatic hydrops (EH) volume after middle ear pressure therapy (MEPT), we investigated changes in EH volume after MEPT for intractable Meniere's disease (MD) by means of the inner ear MRI (ieMRI) in relation to clinical results.

MATERIALS AND METHODS

We enrolled 202 successive definite MD cases with intractable vertiginous symptoms from 2015 to 2020, assigning Group-I of MEPT, and Group-II of endolymphatic sac drainage (ELSD). Ninety patients completed the planned 2-year-follow-up, which included assessment of vertigo frequency and changes in EH volume using ieMRI (Group-I/MEPT: n = 40; Group-II/ELSD: n = 50).

RESULTS

Two years after surgery, vertigo was completely controlled in 77.5% of patients in Group-I and 90.0% in Group-II. Hearing improved by >10 dB in 7.5% of patients in Group-I and 24.0% in Group-II. ELS ratios were significantly reduced after treatments of Group-I and Group-II only in the vestibule.

CONCLUSIONS

The obtained results indicate that MEPT as well as ELSD could be a good treatment option for patients with intractable MD.

Risk factors for the lateral cervical lymph node metastasis of papillary thyroid carcinoma: A clinical study

Currently, there is a lack of evidence-based risk factors for the lateral cervical lymph node metastasis of papillary thyroid carcinoma (PTC). Thus, the risk factors and recurrence rate of lateral cervical lymph node metastasis were investigated in the present study for patients with PTC who underwent initial radical surgery. The data of 274 patients with PTC who underwent initial radical surgery over a 10-year period from January, 2009 to December, 2018 were retrospectively analyzed. By applying univariate analysis, lymphovascular invasion, venous invasion, extrathyroidal infiltration, paratracheal lymph node metastasis and tumor size were designated as significant risk factors for lateral cervical lymph node metastasis. As regards multivariate analysis, paratracheal lymph node metastasis and tumor size were identified as independent risk factors. The recurrence rate was higher in patients presenting with lateral cervical lymph node metastasis, and the disease-free survival rate was significantly lower in the patient group presenting with lateral cervical lymph node metastasis. On the whole, the present study demonstrated that paratracheal lymph node metastasis and tumor size were independent risk factors for lateral cervical lymph node metastasis.

Late-onset and congenital hearing loss detected using AABR due to congenital cytomegalovirus infection that improved with valganciclovir

Congenital cytomegalovirus (cCMV) infection is the most common congenital viral infection and is the leading non-genetic cause of sensorineural hearing loss and an important cause of neurodevelopmental disabilities. Auto auditory brainstem response (AABR) is a simple hearing test and used for the purpose of neonatal hearing screening, but can use it for early detection hard of hearing within the study age of the model. We experienced two case of asymptomatic CMV infection in which congenital and late-onset hearing loss were diagnosed early with AABR, and hearing loss improved with valganciclovir.

Evaluation of changes in endolymphatic hydrops volume after medical treatments for Meniere's disease using 3D magnetic resonance imaging

OBJECTIVE

To elucidate the relationship between vertigo and EH volume after medical treatment, we investigated changes in endolymphatic hydrops (EH) volume using inner ear magnetic resonance imaging (ieMRI) in relation to clinical results for vertigo and hearing after administration of the anti-vertiginous medications betahistine, adenosine triphosphate (ATP), isosorbide (ISO), and saireito (SAI) for Meniere's disease (MD).

METHODS

We retrospectively enrolled 202 consecutive patients diagnosed with unilateral MD from 2015 to 2021 and assigned them to four groups: Group I (G-I), symptomatic oral medication with betahistine only (CONT); Group II (G-II), inner ear vasoactive oral medication (ATP); Group III (G-III), osmotic diuretic oral medication (ISO); and Group IV (G-IV), kampo oral medication (SAI). In total, 172 patients completed the planned one-year-follow-up, which included the assessment of vertigo frequency, hearing improvement, and changes in EH using ieMRI (G-I, n=40; G-II, n=42; G-III, n=44; G-IV, n=46). We constructed 3D MRI images semi-automatically and fused the 3D images of the total fluid space (TFS) of the inner ear and endolymphatic space (ELS). After fusing the images, we calculated the volume ratios of the TFS and ELS (ELS ratios).

RESULTS

One year after treatment, vertigo was controlled with zero episodes per month in 57.5% (23/40) of patients in G-I, 78.6% (33/42) in G-II, 81.8% (36/44) in G-III, and 82.6% (38/46) in G-IV (statistical significance: G-I<G-II=G-III=G-IV). Hearing improved by > 10 dB in 5.0% (2/40) of patients in G-I, 16.7% (7/42) in G-II, 18.2% (8/44) in G-III, and 21.7% (10/46) in G-IV (statistical significance: G-I=G-II=G-III=G-IV). ELS ratios were significantly reduced after treatment only in the vestibule for G-II, G-III, and G-IV when compared with G-I. Especially among patients with complete control of vertigo after treatment, ELS ratios were significantly reduced after treatment in the vestibule and total inner ear for G-II; in the cochlea, vestibule, and total inner ear for G-III; and in the cochlea, vestibule, and total inner ear for G-IV compared with G-I. However, there were no significant findings in the relationship between hearing results and changes in ELS ratios.

CONCLUSION

These results indicate that daily administration of anti-vertiginous medications including ATP, ISO, and SAI could be an effective treatment option for patients with MD at an early stage before it becomes intractable. Treatments to reduce EH might offer better control of vertigo rather than improve hearing.

Relationships between changes in lateral vestibulospinal tract excitability and postural control by dynamic balance intervention in healthy individuals: A preliminary study

Introduction

We conducted dynamic balance or static intervention on healthy young adults to examine the changes in lateral vestibulospinal tract (LVST) excitability and postural control that ensued following dynamic balance intervention and to investigate the correlation between these changes.

Methods

Twenty-eight healthy young adults were randomly assigned to either the dynamic balance group or the control group. They performed either a dynamic balance or static intervention for 10 trials of 30 s each and were assessed for head jerks during the intervention to confirm adaptation to the intervention. The dynamic balance intervention consisted of maintaining balance on a horizontally unstable surface, whereas the control intervention involved standing in the same foot position as the dynamic balance intervention on a stable surface while completing a maze task. LVST excitability and postural stability were assessed before and after the interventions. LVST excitability was assessed as the change rate in the soleus H-reflex amplitude with galvanic vestibular stimulation (GVSH). The velocity and area of the center of pressure (COP) were examined in the eyes closed/foam rubber condition.

Results

No significant main and interaction effects (task, time) were observed for GVSH and COP variables. In the dynamic balance intervention, head jerk significantly decreased, and GVSH-change and changes in head jerk and COP area were significantly negatively correlated.

Discussion

The LVST excitability change for the dynamic balance intervention varied among the participants, although increased LVST excitability may have been related to increased postural stability.

Resection of brachial plexus schwannomas while monitoring transcranial motor evoked potentials: report of two cases

A schwannoma is a benign nerve sheath tumor treated by enucleation, which carries the risk of intraoperative nerve injury that is observed after awakening. Transcranial motor evoked potential (TcMEP) monitoring has been established as an effective method to predict and prevent intraoperative neurological complications during brain and spinal surgery. However, there have been few reports on its application in head and neck surgeries. We performed enucleation to relieve the symptoms due to schwannomas in the neck of two women, aged 25 years and 70 years. Both women presented with a left cervical mass, paresthesia of the left upper limb, and a Tinel-like sign without muscle weakness. TcMEPs were recorded before beginning surgery, during surgery, and immediately before completing surgery. The dissecting lines were decided using the stimulator attached to the dissecting instrument, which helped warn the surgeon regarding risky areas. Histopathological examinations confirmed the diagnosis of schwannoma. There was no significant difference in the pre- and postoperative TcMEP recordings, and no postoperative motor deficits were identified. Intraoperative TcMEP monitoring is expected to be useful in preventing operative complications while treating head and neck schwannomas.

Culture of organoids with vestibular cell-derived factors promotes differentiation of embryonic stem cells into inner ear vestibular hair cells

Vestibular hair cells (V-HCs) residing in the inner ear have important roles related to balance. Although differentiation of pluripotent stem cells into HCs has been shown, an effective method has yet to be established. We previously reported that use of vestibular cell-derived conditioned medium (V-CM) was helpful to induce embryonic stem (ES) cells to differentiate into V-HC-like cells in two-dimensional (2D) cultures of ES-derived embryoid bodies (EBs). In the present report, V-CM was used with three-dimensional (3D) cultures of EBs, which resulted in augmented expression of V-HC-related markers (Math1, Myosin6, Brn3c, Dnah5), but not of the cochlear HC-related marker Lmod3. Gene expression analyses of both 2D and 3D EBs cultured for two weeks revealed a greater level of augmented induction of HC-related markers in the 3D-cultured EBs. These results indicate that a 3D culture in combination with use of V-CM is an effective method for producing V-HCs.

Clinical Study on the Risk Factors for the Recurrence of Papillary Thyroid Carcinoma

INTRODUCTION

Papillary thyroid carcinoma is the most common endocrine malignancy and the most common type of thyroid cancer, accounting for approximately 85% of all thyroid cancer cases. It usually has a favorable course, with the 10-year survival rate exceeding 90%. However, the literature reports a recurrence rate of 7-23% after initial surgical treatment. It is important to consider medical treatment policies for this recurrence.

METHODS

In this study, we examined the risk factors for the recurrence of papillary thyroid carcinoma. We treated 274 patients with thyroid papillary carcinoma at our hospital between 2009 and 2018.

RESULTS

Recurrence occurred in 20 cases (7.3%). Lympho-vascular invasion and lateral cervical lymph node metastasis made significant independent contributions.

CONCLUSION

The selection of the surgical mode should be based on the recurrence and after comprehensive consideration of the clinical features.

Gravity perception disturbance in patients with unilateral Meniere disease

Objective

To investigate gravity perception disturbance (GPD) in patients with Meniere disease (MD), we classified GPD type based on the results of the head-tilt perception gain (HTPG) and the head-upright subjective visual vertical (HU-SVV) evaluated by the head-tilt SVV (HT-SVV) test in patients with unilateral MD.

Methods

We conducted the HT-SVV test on 115 patients with unilateral MD and 115 healthy controls. Among the 115 patients, the period from the first vertigo episode to the examination (PFVE) was known for 91 patients.

Results

The HT-SVV test classified 60.9% and 39.1% of patients with unilateral MD as GPD and non-GPD, respectively. GPD was classified according to HTPG/HU-SVV combinations as follows: Type A GPD (21.7%, normal HTPG/abnormal HU-SVV), Type B GPD (23.5%, abnormal HTPG/normal HU-SVV), and Type C GPD (15.7%, abnormal HTPG/abnormal HU-SVV). As the PFVE became longer, patients with non-GPD and Type A GPD decreased; however, those with Types B and C GPD increased.

Conclusion

This study provides novel information on unilateral MD from the perspective of gravity perception by classifying GPD based on the results of the HT-SVV test. This study's findings suggest that overcompensation for vestibular dysfunction in patients with unilateral MD exhibited by large HTPG abnormalities may be strongly associated with persistent postural-perceptual dizziness.

Level of Evidence

3b.

Head and neck small-cell carcinoma: A multicenter study of 39 cases from 10 institutions

Objective

Basal information of head and neck small-cell carcinoma (HNSmCC) including epidemiology, primary site, treatment, and prognosis remains sparse due to its rarity. We report here a multicenter retrospective study on the diagnosis, treatment, and outcomes of patients with HNSmCC.

Materials and methods

This study involved 47 patients with HNSmCC from 10 participating institutions. Eight patients were excluded for whom no pathological specimens were available (n = 2) and for discrepant central pathological judgements (n = 6). The remaining 39 patients were processed for data analysis.

Results

As pretreatment examinations, computed tomography (CT) was performed for the brain (n = 8), neck (n = 39), and chest (n = 32), magnetic resonance imaging (MRI) for the brain (n = 4) and neck (n = 23), positron emission tomography-CT (PET-CT) in 23 patients, bone scintigraphy in 4, neck ultrasonography in 9, and tumor markers in 25. Primary sites were oral cavity (n = 1), nasal cavity/paranasal sinuses (n = 16), nasopharynx (n = 2), oropharynx (n = 4), hypopharynx (n = 2), larynx (n = 6), salivary gland (n = 3), thyroid (n = 2), and others (n = 3). Stages were II/III/IV-A/IV-B/IV-C/Not determined = 3/5/16/6/5/4; stage IV comprised 69%. No patient had brain metastases. First-line treatments were divided into 3 groups: the chemoradiotherapy (CRT) group (n = 27), non-CRT group (n = 8), and best supportive care group (n = 4). The CRT group included concurrent CRT (CCRT) (n = 17), chemotherapy (Chemo) followed by radiotherapy (RT) (n = 5), and surgery (Surg) followed by CCRT (n = 5). The non-CRT group included Surg followed by RT (n = 2), Surg followed by Chemo (n = 1), RT alone (n = 2), and Chemo alone (n = 3). The 1-year/2-year overall survival (OS) of all 39 patients was 65.3/53.3%. The 1-year OS of the CRT group (77.6%) was significantly better compared with the non-CRT group (31.3%). There were no significant differences in adverse events between the CCRT group (n = 22) and the Chemo without concurrent RT group (n = 9).

Conclusion

Neck and chest CT, neck MRI, and PET-CT would be necessary and sufficient examinations in the diagnostic set up for HNSmCC. CCRT may be recommended as the first-line treatment. The 1-year/2-year OS was 65.3%/53.3%. This study would provide basal data for a proposing the diagnostic and treatment algorithms for HNSmCC.

Temporal Bone Histopathology of Undiagnosed Dizziness in the Elderly

INTRODUCTION

Dizziness is a common disease. However, approximately 10-40% of patients were diagnosed unknown dizziness even though general, neurological, and otological examinations were performed. The aim of this otopathological study was to investigate the histopathology of the peripheral vestibular system of patients who suffered from undiagnosed dizziness.

METHODS

Eighteen temporal bone specimens from 9 patients with undiagnosed dizziness and 20 temporal bone specimens from age-matched 10 normal controls were selected. Cases with a history of dizziness and vertigo caused by particular peripheral vestibular disease and central etiology were excluded. Specimens of the vestibular system were carefully assessed by light microscopy. The basophilic deposits adhered to cupulae of the semicircular canals and the wall of the labyrinth were investigated. Scarpa's ganglion cell counts in the vestibular nerves were performed.

RESULTS

Fifteen ears of 9 patients had the findings of vestibular pathology such as a basophilic deposit on cupula (8 ears), on canal wall (7 ears), vestibular nerve loss (8 ears), or vestibular atelectasis (2 ears). Unclear pathological findings such as crista neglecta, subepithelial deposits of the crista ampullaris, and adhesion of the cupula to dark cell area were demonstrated. The mean size of basophilic deposits seen in the patients (mean: 191 µm) was larger than that of latent deposits seen in the normal controls (mean: 101 µm; p = 0.01).

CONCLUSIONS

We demonstrated some peripheral vestibular pathological findings such as deposit within the semicircular canal, vestibular nerve loss, and vestibular atelectasis and suggested the possible diagnosis of dizziness (benign paroxysmal positional vertigo, presbyvestibulopathy, vestibular atelectasis). These findings will provide a better insight into the multiple etiologies of the unknown dizziness in the elderly.

COVID‑19 and peritonsillar abscess co‑infection: A case report

Coronavirus disease 2019 (COVID-19) generally presents with fever, shortness of breath and a sore throat. These symptoms are also common in oral and pharyngeal infections, such as peritonsillar abscess (PA). The present study describes a case of PA and COVID-19 co-infection. Although COVID-19 was initially suspected in the patient due to the presenting symptoms of fever, sore throat, dysgeusia and dysosmia, an oral examination and computed tomography scan detected PA. The patient was conservatively managed with intravenous antibiotics without transoral drainage of the abscess. Anti-COVID-19 medication was not administered as the COVID-19 infection in the patient was not severe. Laboratory findings revealed high levels of leukocytes, C-reactive protein (CRP) and procalcitonin. On the whole, the association between laboratory findings (including leukocyte count, CRP and procalcitonin levels) and bacterial co-infection with COVID-19 remains unclear, and further studies are warranted. Oral examinations and transoral procedures are often avoided due to the high risk of the aerosolisation of COVID-19 viral particles. However, an appropriate evaluation is essential in order to avoid the underdiagnosis of life-threatening bacterial infections that co-exist with COVID-19.

Estimated number and prevalence of patients with delayed endolymphatic hydrops in Japan: a nationwide survey

BACKGROUND

Delayed endolymphatic hydrops (DEH) is a rare disease, and the actual number of patients in Japan remains unknown.

OBJECTIVE

To investigate the number and prevalence of patients with DEH in Japan.

METHODS

In total, 781 departments of otolaryngology in Japan were selected for survey by stratified random sampling according to the total number of hospital beds. We sent questionnaires to the target departments and collected data regarding the number of patients with DEH who visited those departments in 2019.

RESULTS

The overall response rate was 68.0% (531 departments). The estimate number of patients with DEH in Japan was 962, and the prevalence was calculated to be 0.8 per 100,000 population.

CONCLUSION

Patients with DEH were extremely rare in Japan.

SIGNIFICANCE

This may be the first nationwide epidemiological study on the number and prevalence of patients with DEH in Japan or in the world.

A 14-year nationwide epidemiological analysis of delayed endolymphatic hydrops in Japan

BACKGROUND

Delayed endolymphatic hydrops (DEH) is an inner ear disease that causes recurrent vertigo in the ipsilateral ear or fluctuating hearing in the contralateral ear due to endolymphatic hydrops secondary to preceding deafness. There are few reports of large, multicentre studies investigating the clinical-epidemiological characteristics of DEH.

OBJECTIVE

This study aimed to clarify the characteristics of DEH in Japan.

METHODS

Clinical data on 662 patients with DEH were analysed by nationwide, multicentre surveys conducted by the Peripheral Vestibular Disorders Research Group of Japan.

RESULTS

The proportion of ipsilateral DEH (IDEH) was slightly higher than that of contralateral DEH (CDEH) at 55.4%. The time delay between onset of precedent deafness and onset of DEH was significantly longer for CDEH than for IDEH. The most common cause of precedent deafness was a disease of unknown cause with onset in early childhood (33.1%). Epidemiological characteristics were not significantly different between CDEH with and without vertigo.

CONCLUSION

DEH appearing to be caused by viral labyrinthitis has a high rate of onset within 40 years of precedent deafness. Clinical and epidemiological characteristics of IDEH, CDEH with vertigo, and CDEH without vertigo were very similar.

SIGNIFICANCE

The clinical-epidemiological characteristics of DEH in Japan were clarified.

Role of Human Papilloma Virus and Lifestyle Factors in Overall Survival of Patients with Oropharyngeal Squamous Cell Carcinoma

Background: Patients with human papillomavirus (HPV)-associated oropharyngeal squamous cell carcinoma (OPSCC) have a significantly better treatment response and overall survival (OS) rates than non-HPV-associated OPSCC. Objectives: We conducted the present study to further characterize the interplay between lifestyle risk factors, which are not only HPV status, but also smoking history and alcohol consumption, and the OS to optimize the treatment of patients with OPSCC. Materials and Methods: Between January 2006 and December 2013, 94 patients newly diagnosed with OPSCC were treated with curative intent at Aichi Cancer Center Hospital (Nagoya, Japan). To determine negative prognostic factors associated with the OS, univariate and multivariable Cox regression analyses were performed. Results: Of the 94 OPSCC patients, 53 (56.4%) were positive for HPV. The univariate analysis revealed that T classification, smoking history, alcohol consumption, and HPV status were significant determinants of the OS. In the multivariate analysis, adjusted for the clinical stage, smoking history, alcohol consumption, HPV status, and a smoking history of >10 pack-years was an independent negative prognostic factor for the OS among patients with OPSCC (HR: 10.4, 95 %CI: 1.34−80.6, p < 0.05). Conclusions: Smoking is a very important negative prognostic factor even in cases of HPV-associated OPSCC. The impact of smoking needs to be reaffirmed when deciding on treatment plans and de-escalation trials in OPSCC, even in cases of HPV-associated OPSCC.

Magnetic Resonance 3D Measurement of the Endolymphatic Space in 100 Control Human Subjects

Three Dimensional-magnetic resonance imaging of the inner ear endolymphatic space was performed in 100 control human subjects. Ear endolymphatic space was visualized using contrast-enhanced magnetic resonance imaging with intravenous gadolinium injection. The images were acquired on a 3-tesla magnetic resonance scanner using a 32-channel array head coil for all patients. The ear endolymphatic space and total fluid space volumes of the inner ear, cochlea, and vestibule were measured, and the ear endolymphatic space in the cochlea and vestibule was classified into four categories. The cochlea categories were: c-1, no ear endolymphatic space; c-2, ear endolymphatic space visualized only until the upper turn; c-3, ear endolymphatic space visualized from the upper turn to the second turn; and c-4, ear endolymphatic space visualized up to the basal turn. The vestibule categories were: v-1, no ear endolymphatic space; v-2, ear endolymphatic space visualized only in the utriculus; v-3, ear endolymphatic space visualized in the utriculus and sacculus separately; and v-4, ear endolymphatic space visualized in the utriculus and sacculus together. The mean TFS volumes of the inner ear, cochlea, and vestibule were 282.1 ± 33.2 µL, 112.9 ± 15.9 µL, and 69.1 ± 9.9 µL, respectively, and that of the ampulla of the posterior semicircular canal was 7.8 ± 1.7 µL. The mean ear endolymphatic space/total fluid space volume ratio in the cochlea was 10.3 ± 6.7% and that in the vestibule was 17.3 ± 12.2%. This ratio in the cochlea was between the results of categories c-1 and c-2 and that in the vestibule between those of categories v-2 and v-3. Two subjects had ear endolymphatic space extending from the vestibule to the posterior non-ampullated crus of the lateral semicircular canal. These findings can be applied as standard reference values for further research.

Magnetic resonance imaging of the endolymphatic space in patients with benign paroxysmal positional vertigo: volume ratio and distribution rate of the endolymphatic space

BACKGROUND

Benign paroxysmal positional vertigo (BPPV) is the most common peripheral vestibular disease. It is characterised by sudden onset short lived vertigo triggered by sudden changes in head position relative to gravity.

AIMS/OBJECTIVES

We aimed to perform a quantitative volumetric analysis of the inner ear endolymphatic space in patients with BPPV.

MATERIAL AND METHODS

This study included 67 patients with BPPV and 50 control subjects (CS). The endolymphatic space/total fluid space volume ratio (%) and the distribution rate of the inner ear components in the endolymphatic space (%) were measured using three-dimensional magnetic resonance imaging.

RESULTS

Differences in the endolymphatic space/total fluid space volume ratio of the inner ear, cochlea, vestibule, and semi-circular canals (SCCs) between the CS and BPPV groups were not significant. The endolymphatic space distribution rate of the vestibule in the BPPV group was significantly lower than that in the CS group, and the endolymphatic space distribution rate of SCCs in the BPPV group was significantly higher than that in the CS group.

CONCLUSIONS AND SIGNIFICANCE

Extended endolymphatic space in patients with BPPV did not exist. The otoconia released from the damaged utricles were considered to move with the endolymphatic flow toward SCCs.

Predominance of CTX-M-9 Group Among ESBL-Producing Escherichia coli Isolated from Healthy Individuals in Japan

The detection rate of extended-spectrum β-lactamase (ESBL)-producing Enterobacterales, microorganisms associated with health care settings, has significantly increased worldwide. Moreover, their community incidence has increased in several countries. In this study, we investigated the prevalence and genetic diversity of ESBL-producing Escherichia coli isolated from 547 nonduplicated stool specimens from healthy Japanese individuals, between 2015 and 2019. E. coli were isolated on deoxycholate-hydrogen sulfide-lactose (DHL) agar and identified by MALDI-TOF MS, ESBL were screened through disk diffusion method (cefotaxime with or without clavulanate), and genetic detection and genotyping were performed by PCR and DNA sequencing. Clonal similarities between ESBL-producing and nonproducing isolates were assessed by multilocus sequence typing (MLST). The prevalence of ESBL-producing E. coli was 9.7% (53/547). These bacteria harbored CTX-M genes, from which CTX-M-9 (31/53, 58.5%) and CTX-M-1 (13/53, 24.5%) groups were the predominant. The MLST analysis revealed that ST131 genotype prevailed within ESBL-producing E. coli (15/53), whereas ST95 (10/53) and ST73 (8/53) prevailed among non-ESBL producers, with ST131 being present in only four isolates. Overall, a high prevalence rate of CTX-M-type ESBL-producing E. coli was detected. CTX-M-9 group-producing ST131 predominated among healthy Japanese individuals, similar to that observed in hospital isolates. CTX-M-type ESBL may disseminate clonally among hospital patients and subsequently, within the community.

Orthostatic hemodynamics in the vertebral artery and blood pressure in patients with orthostatic dizziness/vertigo

OBJECTIVES

Orthostatic dizziness/vertigo (ODV) is a common symptom and is believed to occur due to the cerebral hypoperfusion caused by orthostatic hypotension (OH). However, the detailed mechanism underlying ODV onset is poorly understood. The vertebral artery (VA) mainly supplies blood to the central vestibular system; therefore, the orthostatic decrease of VA blood flow could possibly lead to ODV. This study investigated the orthostatic blood pressure and VA hemodynamics in ODV patients to elucidate the hemodynamic mechanism underlying ODV onset. Furthermore, the influence of orthostatic hypotension (OH) on VA hemodynamics was examined because OH is probably the most common cause of ODV.

METHODS

This study included 181 patients with ODV and 73 control patients without ODV. All subjects underwent an active standing test to measure the extracranial Doppler (ECD) sonography spectrum of the VA and blood pressure (BP). VA blood flow velocity and BP were simultaneously measured for each patient in the supine static position and then in the upright standing positions following 3 min of standing. We investigated the orthostatic change in the average of flow velocity in bilateral VAs (VAFV) and BP for ODV patients compared with the control patients.

RESULT

VAFV in ODV patients was significantly reduced when standing up compared with the control patients. In the ODV patients, there was no difference in orthostatic decrease in VAFV between patients those with OH and without OH. However, the VAFV in the standing position was significantly lower in patients with OH than without OH. In cases with OH, the ODV patients exhibited a greater decrease in VAFV compared with the control patients, but this was not statistically significant. In the absence of OH, a significantly greater orthostatic decrease in VAFV was observed in ODV patients compared with the controls.

CONCLUSION

Our findings suggest that the orthostatic decrease of VA blood flow is deeply involved in the hemodynamic mechanism underlying ODV onset and is possibly associated with OH and other etiologies.

Four cases of medullary thyroid carcinomas associated with multiple endocrine neoplasia 2B with rearranged during transfection codon M918T mutation in the same family

Multiple endocrine neoplasia (MEN) with medullary thyroid carcinoma (MTC) is associated with rearranged during transfection (RET) mutations. The authors encountered four cases of MTC-related MEN type 2B (MEN2B) with RET codon M918T mutation in one family. Case 1 included a 19 year-old male diagnosed with MTC with lung metastases. Genetic testing revealed an RET codon M918T mutation, which indicated MEN2B. The patient responded partially to vandetanib and the disease has shown no progression in 25 months. Case 2 involved the mother of the patient in Case 1. She underwent total thyroidectomy (TT) when diagnosed with MTC-related MEN2B at 12 years of age, but was not counseled adequately. Cases 3 and 4 involved the sisters of the Case 1 patient and were assessed after Case 1 was diagnosed. Genetic testing revealed the same mutation. Case 3 was diagnosed with MTC and underwent TT. Case 4 was asymptomatic but underwent prophylactic TT; histopathologic examination revealed MTC tissue. Prophylactic TT prevented MTC from being detected at an advanced state. Genetic counseling is essential in treating MEN2B. The mother was uninformed about the genetic characteristics of MEN2B, delaying the detection of MTC in her children. The present study reaffirms the importance of family history and screening.

Magnetic resonance imaging of endolymphatic hydrops in patients with unilateral Meniere's disease: volume ratio and distribution rate of the endolymphatic space

BACKGROUND

Endolymphatic hydrops (ELH), which is a pathological feature of Meniere's disease (MD), is characterized by an extended endolymphatic space (ELS).

AIMS/OBJECTIVES

We aimed to perform a quantitative volumetric analysis of inner-ear ELH in patients with unilateral MD (uMD).

MATERIAL AND METHODS

This study included 97 patients with definite uMD and 49 control subjects (CS). The ELS/total fluid space (TFS) volume ratio (%) and the distribution rate of the inner-ear components in the ELS (%) were measured using 3D magnetic resonance imaging and compared between patients with uMD and CS.

RESULTS

Compared to CS, patients with uMD had significantly higher mean ELS/TFS volume ratios for inner-ear components. The mean distribution rate of the inner-ear components in the ELS was not significantly different between the two groups.

CONCLUSIONS AND SIGNIFICANCE

In patients with uMD, ELH was noted to be spread throughout the entire inner ear and the endolymph was evenly distributed in the total ELS. These findings should be useful as a standard reference for further research.

Head Roll-Tilt Subjective Visual Vertical Test in the Diagnosis of Persistent Postural-Perceptual Dizziness

OBJECTIVE

To examine the validity of head roll-tilt subjective visual vertical (HT-SVV) in diagnosing persistent postural-perceptual dizziness (PPPD).

STUDY DESIGN

Retrospective review.

SETTING

Tertiary referral center.

PATIENTS

Sixty-one patients with PPPD, 10 with unilateral vestibular hypofunction (UVH), and 11 with psychogenic dizziness (PD), showing chronic vestibular symptoms for >3 months.

INTERVENTIONS

Head-tilt perception gain (HTPG, i.e., mean perceptual gain [perceived/actual tilt angle]) during right or left head tilt of approximately 30° (HT-SVV) and conventional head-upright SVV (UP-SVV) were measured. Bithermal caloric testing, cervical and ocular vestibular-evoked myogenic potentials (cVEMP and oVEMP), and posturography were conducted.

MAIN OUTCOME MEASURES

Multiple comparisons were performed for the HT-SVV and other vestibular tests among the disease groups. A receiver operating characteristic curve was created to predict PPPD using HTPG.

RESULTS

HTPG was significantly greater in the PPPD group than in the UVH and PD groups. There were no significant differences in UP-SVV, cVEMP, oVEMP, and posturography (foam ratio and Romberg ratio on foam) among the disease groups, while the UVH group had the highest canal paresis compared to the other two groups. The area under the curve of the receiver operating characteristic curve for predicting PPPD was 0.764, and the HTPG value of 1.202 had a specificity of 95.2% for diagnosing PPPD.

CONCLUSIONS

While conventional vestibular tests including UP-SVV, VEMPs, and posturography did not show abnormalities in PPPD, high HTPG in the HT-SVV test, an excessive perception of head tilt, can be a specific marker for discriminating PPPD from other chronic vestibular diseases.

Effect of transducer placements on thresholds in ears with an abnormal ear canal and severe conductive hearing loss

OBJECTIVES

Providing hearing compensation to patients with aural atresia is considerably challenging. Hearing aid transducers vibrating the aural cartilage (cartilage conduction; CC) have been devised, and hearing aids utilizing them (CC hearing aids) have quickly become a beneficial option for aural atresia in clinical applications. However, it remains unclear which placement (on the aural cartilage or mastoid) is beneficial to signal transmission.

METHODS

This study included 35 patients (53 ears with an abnormal ear canal and severe conductive hearing loss) who were using CC hearing aids. Thresholds were compared between the transducers on the aural cartilage and on the mastoid.

RESULTS

In ears with bony aural atresia, thresholds were significantly improved when the transducer was placed on the aural cartilage compared to when it was placed on the mastoid for frequencies ≤ 500 Hz (P < .05). In aural atresia ears with a fibrotic tissue pathway, the aural cartilage stimulation improved the thresholds by approximately 20 dB for frequencies ≤ 1000 Hz (P < .05). In non-atretic ears, the aural cartilage locations significantly worsened the threshold at 4000 Hz (P < .05).

CONCLUSION

Our findings demonstrated that placing the transducer at the aural cartilage improved the mid-to-low frequency thresholds compared to mastoid transduction in aural atretic ears. In contrast, no clear improvement to the signal transmission due to the transducer's placement on the aural cartilage was recognized in non-atretic ears.

LEVEL OF EVIDENCE

2.

Posturographic Findings in Patients With Psychological Dizziness

BACKGROUND

The diagnosis and treatment of patients with psychogenic vertigo (PSY) is difficult because of the lack of reliable objective findings for this condition. We examined the characteristics of foam posturography in patients with peripheral vestibular disorders (PVD) and those with PSY. In particular, we focused on the objective findings of foam posturography in PSY.

METHODS

Between January 2010 and December 2011, 2-legged stance tasks were conducted in patients with vertigo/dizziness under 4 conditions: eyes opened with/without foam rubber and eyes closed with/without foam rubber. In terms of the velocity of movement of the center of pressure, we examined Romberg ratios, that is, the ratios of changes in visual conditions under the fixed foam rubber conditions, and foam rubber ratios, that is, the ratios of changes in foam rubber conditions under fixed visual conditions. These ratios were compared among 3 groups: healthy controls (CONT) (n=195), PVD (n=178), and PSY (n=32).

RESULTS

Romberg ratios using foam rubber in the PVD group were significantly higher than those in the CONT group. Those in the PSY group were significantly lower. Likewise, the foam rubber ratios in the PVD group were significantly higher than those in the CONT group when the eyes were closed. Those in the PSY group were significantly lower.

CONCLUSION

Judging from scores in Romberg ratios using foam rubber and foam rubber ratios when eyes were closed, foam posturography might have the potential to differentiate PSY from PVD.

Surgical technique for the prevention of tracheal necrosis following total pharyngolaryngectomy

Total pharyngolaryngectomy with cervical esophagectomy (TPLCE) is an invasive procedure with various post-operative complications. Tracheal necrosis (TRN) is a fatal complication of TPLCE. The present study aimed to identify a surgical technique which may be used to prevent TRN. The post-operative complications of 48 patients who underwent TPLCE from January, 2010 to December, 2019 were retrospectively investigated. The incidence of TRN was examined and measures against TRN were reviewed. The results revealed that 3 patients (6%) experienced TRN within 1 week following surgery. In addition, 2 patients required the surgical debridement of the necrotic tissue and tracheoplasty. The other patient underwent conservative treatment. Stomal recurrence developed in 1 patient (2%). On the whole, the present study demonstrates that the incidence of TRN following TPLCE is lower than that observed in previous reports, and only one stomal recurrence was reported. Preserving the blood supply to the trachea is essential for the prevention of TRN. The eight surgical processes used herein effectively preserved the blood supply. Further investigations however, are necessary in order to confirm the present findings and to ensure effective measures are found with which to prevent TRN following TPLCE.

Endolymphatic Sac Drainage Surgery and Plasma Stress Hormone Vasopressin Levels in Meniere's Disease

Meniere's disease is a common inner ear disorder accompanied by vertigo attacks and fluctuating hearing loss that some believe is due to a stressful lifestyle. To elucidate the scientific relationship in neuro-endocrinology between Meniere's disease and stress, we examined the surgical results of endolymphatic sac drainage surgery and changes in stress-induced plasma arginine-vasopressin levels. We enrolled 100 intractable Meniere's patients and examined surgical results and plasma vasopressin levels. Fifty-four chronic otitis media patients who underwent tympano-mastoidectomy formed a control group. We assessed surgical results during a 2-year follow-up period, including vertigo and hearing loss. We examined plasma vasopressin levels just before surgery and 1 week, 1 year, and 2 years after surgery. In patients with intractable Meniere's disease, plasma vasopressin levels were significantly reduced 1 week after surgery compared to the decrease observed in chronic otitis media patients after tympano-mastoidectomy. In intractable Meniere's disease, long-lasting low plasma vasopressin levels after surgery were associated with significantly good surgical results. In recurrent Meniere's disease, a gradual plasma vasopressin level elevation was observed after surgery, followed by recurrent vertigo attacks and sensorineural hearing loss. It is suggested that long-lasting high levels of plasma vasopressin could have adverse effects on inner ear water metabolism and the subsequent Meniere's disease symptoms. Effective treatments for Meniere's disease might be best based on the maintenance of low plasma vasopressin levels.

Changes in the Results of the Subjective Visual Vertical Test After Endolymphatic Sac Drainage for Intractable Meniere's Disease

Objective:

To investigate otolithic function before and after endolymphatic sac drainage (ELSD) for Meniere’s disease (MD) by using the subjective visual vertical test (SVV) in the upright and tilted positions.

Methods:

Eighteen patients with definite unilateral MD diagnosed in accordance with the American Academy of Otolaryngology Head and Neck Surgery criteria in 1995 and Barany Society criteria in 2015 were included. SVV in the upright position and the head-tilt position was performed preoperatively and on postoperative days 1, 5, 8, 28, and 112. Changes in the results of SVV in the upright position (UP-SVV) and head-tilt perception gain (HTPG) after surgery were measured.

Results:

The average UP-SVV values significantly changed from 0.05° by the affected side before surgery to 2.5° by the unaffected side on the fifth postoperative day, followed by recovery to the normal range by the eighth postoperative day. The HTPG values for the unaffected side showed the maximum increase on postoperative day 5 during the present study period, although the values in the affected side did not alter significantly.

Conclusion:

ELSD for MD is a surgical treatment that involves less risk of otolith function damage and abnormalities in gravitational cognition. SVV in the head-tilt position could be one of the neuro-otologic examinations used to easily understand the vestibular compensatory process.

The Third Mobile Window Effects in Otology/Neurotology

It has been revealed that the pure-tone audiometry demonstrates large air-bone gaps at low pitches due to the presence of inner ear fistulae. When a third mobile window resulting from an inner ear fistula is present, in addition to the 2 normally present windows consisting of the oval window and the round window, a portion of the air-conducted waves escape from the scala vestibuli through the inner ear fistula. On the other hand, bone-conducted waves traveling to the scala vestibuli are reduced by an inner ear fistula; however, bone-conducted waves traveling to the scala tympani are not affected by an inner ear fistula. This results in a larger gap than usual in compliance between both perilymphatic spaces and leads to a decrease in the bone conduction threshold.

This phenomenon, so-called the third mobile window effects, sometimes may lead otology/neuro-otology surgeons to misunderstand the reason why large air-bone gaps still exist after ossicular reconstruction in tympanoplasty. This review article gives good examples regarding the third mobile window effects in otology/neuro-otology diseases and surgeries.

Development of a new method for assessing otolith function in mice using three-dimensional binocular analysis of the otolith-ocular reflex

In the interaural direction, translational linear acceleration is loaded during lateral translational movement and gravitational acceleration is loaded during lateral tilting movement. These two types of acceleration induce eye movements via two kinds of otolith-ocular reflexes to compensate for movement and maintain clear vision: horizontal eye movement during translational movement, and torsional eye movement (torsion) during tilting movement. Although the two types of acceleration cannot be discriminated, the two otolith-ocular reflexes can distinguish them effectively. In the current study, we tested whether lateral-eyed mice exhibit both of these otolith-ocular reflexes. In addition, we propose a new index for assessing the otolith-ocular reflex in mice. During lateral translational movement, mice did not show appropriate horizontal eye movement, but exhibited unnecessary vertical torsion-like eye movement that compensated for the angle between the body axis and gravito-inertial acceleration (GIA; i.e., the sum of gravity and inertial force due to movement) by interpreting GIA as gravity. Using the new index (amplitude of vertical component of eye movement)/(angle between body axis and GIA), the mouse otolith-ocular reflex can be assessed without determining whether the otolith-ocular reflex is induced during translational movement or during tilting movement.

Speech recognition scores in bilateral and unilateral atretic ears

OBJECTIVE

Congenital aural atresia causes severe conductive hearing loss disturbing auditory development. The differences in speech recognition were investigated between bilateral and unilateral aural atresia.

DESIGN

The maximum speech recognition scores (SRSs) were compared between patients with bilateral and unilateral aural atresia. In patients with unilateral aural atresia, the maximum SRSs were compared between the atretic and unaffected ears. Furthermore, the correct response rates for test material monosyllables were compared with those of patients with sensorineural hearing loss (SNHL), which had been previously obtained.

STUDY SAMPLE

Twenty-four patients with aural atresia (8 bilateral, and 16 unilateral) participated.

RESULTS

The maximum SRS in unilateral atretic ears (median: 72%) was significantly lower than that in unaffected ears (median: 89%) (p < 0.05) and in bilateral atretic ears (median: 91%) (p < 0.05). Patients with aural atresia had relatively high correct response rates for monosyllables with low correct response rates by patients with SNHL. Conversely, incorrect responses were obtained for several words for which high correct-response rates were attained by patients with SNHL.

CONCLUSIONS

Poor unilateral atretic-ear development may induce low speech recognition, and the mechanisms underlying speech-recognition reduction differ from those in SNHL.

Word Categorization of Vowel Durational Changes in Speech-Modulated Bone-Conducted Ultrasound

Ultrasound can deliver speech information when it is amplitude-modulated with speech and presented via bone conduction. This speech-modulated bone-conducted ultrasound (SM-BCU) can also transmit prosodic information. However, there is insufficient research on the recognition of vowel duration in SM-BCU. The aim of this study was to investigate the categorization of vowel durational changes in SM-BCU using a behavioral test. Eight Japanese-speaking participants with normal hearing participated in a forced-choice behavioral task to discriminate between "hato" (pigeon) and "haato" (heart). Speech signal stimuli were presented in seven duration grades from 220 ms to 340 ms. The threshold at which 50% of responses were "haato" was calculated and compared for air-conducted audible sound (ACAS) and SM-BCU. The boundary width was also evaluated. Although the SM-BCU threshold (mean: 274.6 ms) was significantly longer than the ACAS threshold (mean: 269.6 ms), there were no differences in boundary width. These results suggest that SM-BCU can deliver prosodic information about vowel duration with a similar difference limen to that of ACAS in normal hearing.

A study of 24 cases of salivary gland carcinoma with distant metastasis

Salivary gland carcinoma is a relatively rare disease of the head and neck. Although it frequently presents with distant metastases, few reports have been published on this subject. The present study investigated the prognosis of patients with distant metastases from salivary gland cancer. A total of 24 cases of salivary gland carcinoma with distant metastasis who were initially treated at the Department of Otolaryngology-Head and Neck Surgery of Nara Medical University during a 16-year period from August 2004 to July 2020 were included. The histopathological types included salivary duct carcinoma (8 cases), adenoid cystic carcinoma (6 cases), myoepithelial carcinoma (3 cases), Squamous cell carcinoma (2 cases), adenocarcinoma (2 cases), acinic cell carcinoma (2 cases) and mucoepidermoid carcinoma (1 case). A total of 18 patients had stage IV carcinoma, which represented the majority. Of all patients, ~80% developed distant metastases within 2 years of initial diagnosis. Survival rates after the appearance of distant metastases were 43.5% at 5 years and 14.5% at 10 years. The results of the current study revealed that no factors significantly influenced long-term prognosis after the development of distant metastases. In future, it may be necessary to re-examine these results in a larger sample size and standardise treatment methods as a result.

Magnetic resonance imaging of endolymphatic hydrops in patients with unilateral Meniere's disease: a comparison between with and without herniation into the posterior and lateral semi-circular canals

BACKGROUND

The presence of endolymphatic hydrops (ELH) in patients with Meniere's disease (MD) is considered a pathological hallmark.

AIMS/OBJECTIVES

We aimed to conduct a quantitative volumetric measurement of inner ear ELH in patients with unilateral MD (uMD). The values of uMD with and without herniation into the posterior semi-circular canal (h-PSC) and the lateral semi-circular canal (h-LSC) were compared using 3 D magnetic resonance imaging.

MATERIAL AND METHODS

This study included 130 individuals (47 controls and 83 patients with uMD). We measured the total fluid space (TFS) and endolymphatic space (ELS) volumes. We also evaluated the ELS/TFS volume ratios (%).

RESULTS

The ELS/TFS volume ratios in the inner ear, cochlea, and vestibule were significantly different between the affected and contralateral sides in patients with h-PSC. Moreover, the ELS/TFS volume ratios of the inner ear, vestibule, and semi-circular canals in the affected ear were significantly higher in patients with h-PSC than in those without h-PSC. The vestibular ELS/TFS volume ratio in the affected ear was significantly higher in patients with h-LSC than in those without h-LSC.

CONCLUSIONS AND SIGNIFICANCE

H-LSC is present in extended vestibular ELH. However, this is a result of ELH progression in the inner ear.

Novel Magnetic Resonance Imaging-Based Method for Accurate Diagnosis of Meniere's Disease

Background: Pathologically, Meniere's disease symptoms are considered to be associated with endolymphatic hydrops. Examinations revealing endolymphatic hydrops can be useful for accurate Meniere's disease diagnosis. We previously reported a quantitative method for evaluating endolymphatic hydrops, i.e., by measuring the volume of the endolymphatic space using three-dimensional magnetic resonance imaging (MRI) of the inner ear. This study aimed to confirm the usefulness of our methods for diagnosing Meniere's disease. Here, we extracted new explanatory factors for diagnosing Meniere's disease by comparing the volume of the endolymphatic space between healthy volunteers and patients with Meniere's disease. Additionally, we validated our method by comparing its diagnostic accuracy with that of the conventional method.

Methods and Findings: This is a prospective diagnostic accuracy study performed at vertigo/dizziness centre of our university hospital, a tertiary hospital. Eighty-six patients with definite unilateral Meniere's disease and 47 healthy volunteers (25 and 33 males, and 22 and 53 females in the control and patient groups, respectively) were enrolled. All participants underwent 3-Tesla MRI 4 h after intravenous injection of gadolinium to reveal the endolymphatic space. The volume of the endolymphatic space was measured and a model for Meniere's disease diagnosis was constructed and compared with models using conventional criteria to confirm the effectiveness of the methods used. The area under the receiver operating characteristic curve of the method proposed in this study was excellent (0.924), and significantly higher than that derived using the conventional criteria (0.877). The four indices, sensitivity, specificity, positive predictive value, and negative predictive value, were given at the threshold; all of these indices achieved higher scores for the 3D model compared to the 2D model. Cross-validation of the models revealed that the improvement was due to the incorporation of the semi-circular canals.

Conclusions: Our method showed high diagnostic accuracy for Meniere's disease. Additionally, we revealed the importance of observing the semi-circular canals for Meniere's disease diagnosis. The proposed method can contribute toward providing effective symptomatic relief in Meniere's disease.

Investigation of endolymphatic hydrops positivity rates in patients with recurrent audiovestibular symptoms using inner ear magnetic resonance imaging

OBJECTIVES

This study aimed to investigate the endolymphatic hydrops (EH)-positivity rates among patients with recurrent audiovestibular symptoms using intravenous injection of gadolinium-enhanced inner ear magnetic resonance imaging (ieMRI).

METHODS

We reviewed 710 successive patients with recurrent audiovestibular symptoms at the Vertigo/Dizziness Center of Nara Medical University and other related hospitals, between May 2014 and April 2020. We performed ieMRI on 153 patients with unilateral recurrent cochleovestibular symptoms (rCV), 51 with recurrent vertigo symptoms (rVO), and 84 with unilateral recurrent cochlear symptoms (rCO).

RESULTS

EH was observed in 69.4% of the participants: 81.7% in the rCV group, 19.6% in the rVO group, and 77.4% in the rCO group. The participants were divided into two groups according to the disease duration: short-duration and long-duration groups. In the short-duration group (less than 4 years), EH was observed in 82.3%, 42.9%, and 71.4% of the patients in rCV, rVO, and rCO groups, respectively; in the long-duration group (more than 5 years), EH was observed in 81.1%, 10.8%, and 81.6% of the patients in rCV, rVO, and rCO groups, respectively.

CONCLUSIONS

The longer the duration of the disease, the larger the EH-positivity rates in patients with rCO, smaller in those with rVO, and unchanged in those with rCV. Although ieMRI could not detect EH with 100% accuracy in Ménière's disease, the present pathological statistics of patients with recurrent audiovestibular symptoms might be helpful in considering the pathology-based treatment strategy.