Effects of sound source localization of masking sound on perception level of simulated tinnitus.

Tinnitus therapies have been combined with the use of varieties of sound/noise. For masking external sounds, location of the masker in space is important; however, effects of the spatial location of the masker on tinnitus are less understood. We aimed to test whether a masking sound location would affect the perception level of simulated tinnitus. The 4 kHz simulated tinnitus was induced in the right ear of healthy volunteers through an open-type earphone. White noise was presented to the right ear using a single-sided headphone or a speaker positioned on the right side at a distance of 1.8 m for masking the simulated tinnitus. In other sessions, monaurally recorded noise localized within the head (inside-head noise) or binaurally recorded noise localized outside the head (outside-head noise) was separately presented from a dual-sided headphone. The noise presented from a distant speaker and the outside-head noise masked the simulated tinnitus in 71.1% and 77.1% of measurements at a lower intensity compared to the noise beside the ear and the inside-head noise, respectively. In conclusion, spatial information regarding the masking noise may play a role in reducing the perception level of simulated tinnitus. Binaurally recorded sounds may be beneficial for an acoustic therapy of tinnitus.

Traumatic Nonmissile Penetrating Transnasal Anterior Skull Base Fracture and Brain Injury with Cerebrospinal Fluid Leak: Intraoperative Leak Detection and an Effective Reconstruction Procedure for a Localized Skull Base Defect Especially After Coronavirus Disease 2019 Outbreak.

BACKGROUND: Cerebrospinal fluid (CSF) leakage after penetrating skull base injury is relatively rare compared with close head injuries involving skull base fractures. CASE DESCRIPTION: We report the case of a 65-year-old man who had presented with epistaxis and serous rhinorrhea. When he had fallen to the ground near his bee boxes, a garden pole had poked into his right nostril. He had instantly removed the pole from his nostril himself. However, immediately after removal of the pole, he had developed nasal bleeding and serous rhinorrhea. He then drove to our emergency room. Computed tomography showed pneumocephalus with a minor cerebral contusion in the left frontal lobe and a penetrating injury in the left anterior skull base. His CSF leakage had not resolve spontaneously within 1 week after the injury with strict bed rest. We repaired the CSF leakage using a fat (adipose tissue)-on-fascia autograft plug and caulked the defect in the anterior skull base with the fat-on-fascia graft (FFG) plug through the left nostril with endoscopic guidance. The CSF rhinorrhea was successfully controlled. Intranasal local application of fluorescein aided in the detection of the direction of flow of the CSF leakage. CONCLUSIONS: Endonasal endoscopic caulking of a skull base defect using an FFG plug can be useful to treat CSF leakage due to the localized skull base defect, especially in the coronavirus disease 2019 pandemic. It is simple, inexpensive, and timesaving. It requires no special skills nor sophisticated instruments that can cause aerosolization, reducing the risk of infection during the surgery.

Patient-specific 3D-printed Model-assisted Supracochlear Approach to the Petrous Apex.

OBJECTIVE: To present a case of pediatric cholesteatoma that invaded the petrous apex (PA) and discuss the usefulness of preoperative three-dimensional (3D) surgical simulation on a personal computer (PC) and patient-specific 3D printed model-assisted surgery. PATIENT: A 5-year-old boy with congenital cholesteatoma underwent a planned two-stage canal wall up mastoidectomy. The cholesteatoma had invaded the PA from a small space anterior to the superior semicircular canal (SSCC). During the removal of this lesion in the first surgery, the tip of a 1-mm round knife broke off and fell into the PA. The surgeon could not remove it, as it was thought that opening the space might damage the SSCC and the facial nerve (FN). INTERVENTION: Before the second surgery, a preoperative 3D surgical simulation on a PC was performed, and an approach to the PA via the triangle surrounded by the SSCC, FN, and middle cranial fossa, namely, the supracochlear approach, was discovered. A patient-specific 3D-printed model, which had been drilled to make each surface of the triangle including the SSCC, FN, and middle cranial fossa visible in the PC simulation surgery, was then created and a 3D-printed model-assisted surgery was planned. RESULTS: By placing the sterilized patient-specific 3D model close to the surgical field, the cholesteatoma and iatrogenic foreign body could be successfully removed from the PA without damaging the important surrounding structures. CONCLUSIONS: Preoperative 3D surgical simulations and intraoperative patient-specific 3D-printed model-assisted surgeries are new, powerful tools that aid in performing challenging surgeries on temporal bones.

Effects of unilateral sinonasal surgery on sleep-disordered breathing.

Aims/objectives: To examine the effects of surgery for unilateral sinonasal lesions on sleep-disordered breathing (SDB). Material and methods: Oxygen desaturation index (3%ODI) as a marker of SDB and bilateral/unilateral nasal resistance were measured before and after surgery for 18 patients with unilateral sinonasal lesions. Various parameters were compared between those who achieved 60% or less decrease of 3%ODI and those who did not. Results: Bilateral nasal resistance as well as that of the surgical side five days after surgery was significantly lower than those of pre-operative value. Preoperative 3%ODI (times/hour) was 10.08 ± 7.32, which significantly decreased to 7.67 ± 5.79 five days after surgery. Even in unilateral patients, sinonasal surgery could reduce the bilateral nasal resistance, resulting in a decrease in 3%ODI. Age was younger and postoperative nasal resistance of the surgical side was significantly lower in the group who achieved 60% or less decrease in 3%ODI than those who did not. Conclusions and significance: SDB is influenced by even unilateral nasal obstruction. Surgery for unilateral lesion can improve the respiration during sleep as well as bilateral nasal resistance. Favorable outcome by surgery could be brought about in younger patients and those for whom sufficient improvement of nasal resistance was expected by surgery.

Medial pontomedullary junctional infarction presenting vertigo, ipsilateral facial paresis, contralateral thermal hypoalgesia and dysphagia without lateral gaze palsy, curtain sign and hoarseness: a case presentation of a novel brain stem stroke syndrome with sensory disturbance-based dysphagia and review of the literature.

In this report, we describe unilateral medial pontomedullary junction (MPMJ) syndrome as a novel brain stem stroke syndrome. A 68-year-old woman suddenly developed vertigo, ipsilateral facial paresis, contralateral thermal hypoalgesia (TH) and dysphagia without lateral gaze palsy, curtain sign and hoarseness. Magnetic resonance (MR) imaging showed a small infarction at the right MPMJ. MR angiography did not show vertebrobasilar arterial dissection, thrombosis or vasospasm. Finally, her dysphagia regressed over 4 weeks in synchronization with recovery of TH. To the best of our knowledge and based on a review of the literature, this MPMJ syndrome associated with the unilateral MPMJ infarction is a novel brain stem stroke syndrome different from Foville syndrome, Millard-Gubler syndrome, Wallenberg syndrome or Dejerine's syndrome. In the MPMJ syndrome, transient, albeit severe, dysphagia based on the TH-impaired swallowing reflex bothered the patient more than hemiparesthesia of TH did.

[RESULTS OF TONSILLECTOMY AND STEROID PULSE THERAPY IN 20 CASES OF RECURRENT IgA NEPHROPATHY AFTER KIDNEY TRANSPLANTATION].

(Background) The standard treatment for recurrent immunoglobulin A nephropathy (rIgAN) after kidney transplantation (KTx) has not been established. (Methods) The results of treatment consisting of tonsillectomy and steroid pulse therapy in 20 recipients who were diagnosed as rIgAN were retrospectively analyzed. (Results) The level of proteinuria significantly decreased from 0.84±0.81 g/day to 0.27±0.31 g/day after treatment (P=0.007). Microscopic hematuria disappeared or improved in 58.3% and 66.6% of recipients 6 and 12 months after treatment, respectively. Serum creatinine levels remained stable for 5 years by the treatment, except for 3 cases of graft loss. Sixteen recipients received renal graft biopsies before and after treatment. Mesangial IgA deposition were dramatically decreased in 7 recipients (43.75%). The degree of mesangial hypercellularity, endocapillary hypercellularity, and crescents formation improved in 3 (18.8%), 6 (37.5%), and 4 (25%) recipients after treatment. (Conclusion) Steroid pulse therapy combined with tonsillectomy may be clinically and histopathologically effective treatment for rIgAN after KTx.

Reliability and validity of the Japanese version of the Glasgow Edinburgh Throat Scale (GETS-J): Use for a symptom scale of globus sensation.

OBJECTIVE: Globus sensation, a feeling of lump or something stuck in the throat, could be caused by structural, functional, and psychogenic diseases. Due to a possible multifactorial nature of the disease, neither diagnosing test battery nor standard treatment for globus sensation has been established. Therefore, a questionnaire to accurately identify globus patients and evaluate the severity of the disease is desired. Glasgow Edinburgh Throat Scale (GETS) is a 10-item questionnaire about the throat symptoms consisting of three subscales relating to dysphagia, globus sensation, and pain/swelling in the throat. It was reported that globus patients marked high scores specifically for the globus scale among three scales, indicating that GETS can be used as a valid symptom scale for globus sensation. Aims of this study were to translate GETS into Japanese and to test its reliability and validity. METHODS: Fifty-five patients complaining of globus sensation without abnormal endoscopic and CT findings were enrolled into the study. They were asked to answer the questions of GETS translated into Japanese (GETS-J). Reliability (internal consistency) of the questionnaire was tested using Cronbach's coefficient alpha. To test the validity, principal components analysis was used to identify the factorial structure of the questionnaire and GETS-J data were compared with those reported in the original GETS. Contribution of psychiatric comorbidities to globus sensation was also investigated by examining the correlation between Hospital Anxiety and Depression Scale (HADS) and GETS-J. RESULTS: Reliability of the questionnaire examined by the Cronbach's coefficient alpha was satisfactory and all higher than 0.75. Principal components analysis identified following three questions as the globus scale: Q1, Feeling something stuck in the throat; Q5, Throat closing off; Q9, Want to swallow all the time. Somatic distress, i.e., patients' reaction to throat symptoms, was significantly correlated with globus scale (r=0.680). Anxiety component of HADS was significantly correlated with somatic distress but not with globus scale. These results were consistent with those of the original GETS except for the replacement of Q3 (discomfort/irritation in the throat) to Q5 (throat closing off) for globus scale in GETS-J. CONCLUSION: Translation of GETS into Japanese showed high reliability and validity, suggesting that translation and cross-cultural adaptation were not problematic. High correlation of globus scale of GETS-J with somatic distress indicated that GETS-J could be a useful questionnaire to identify the globus patients and evaluate the severity of the disease. Anxiety may complicate the somatic distress in patients with globus sensation.

Comprehensive microbiome analysis of tonsillar crypts in IgA nephropathy.

BACKGROUND: Immunoglobulin A nephropathy (IgAN) is the most prevalent primary chronic glomerular disease, in which the mucosal immune response elicited particularly in the tonsils or intestine has been estimated to be involved in the development of the disease. To explore the relationship between IgAN and bacterial flora in the tonsils, we conducted a comprehensive microbiome analysis. METHODS: We enrolled 48 IgAN patients, 21 recurrent tonsillitis (RT) patients without urine abnormalities and 30 children with tonsillar hyperplasia (TH) who had undergone tonsillectomy previously. Genomic DNA from tonsillar crypts of each patient was extracted, and V4 regions of the 16S ribosomal RNA gene were amplified and analysed using a high-throughput multiplexed sequencing approach. Differences in genus composition among the three study groups were statistically analysed by permutational multivariate analysis of variance and visualized by principal component analysis (PCA). RESULTS: Substantial diversity in bacterial composition was detected in each sample. Prevotella spp., Fusobacterium spp., Sphingomonas spp. and Treponema spp. were predominant in IgAN patients. The percentage of abundance of Prevotella spp., Haemophilus spp., Porphyromonas spp. and Treponema spp. in IgAN patients was significantly different from that in TH patients. However, there was no significant difference in the percentage of abundance of any bacterial genus between IgAN and RT patients. PCA did not distinguish IgAN from RT, although it discriminated TH. No significant differences in microbiome composition among the groups of IgAN patients according to clinicopathological parameters were observed. CONCLUSIONS: Similar patterns of bacteria are present in tonsillar crypts of both IgAN and RT patients, suggesting that the host response to these bacteria might be important in the development of IgAN.

Mechanisms and prevention of sudden death in multiple system atrophy.

BACKGROUND: Sudden death in multiple system atrophy (MSA) usually occurs during sleep and was therefore attributed to suffocation resulting from vocal cord abductor paralysis, a characteristic laryngeal finding of MSA. This led to the use of tracheostomy and noninvasive positive pressure ventilation (NPPV) for the prevention of sudden death. However, neither method has been able to prevent sudden death, and both have occasionally precipitated treatment-related complications, including central sleep apneas and exacerbation of floppy epiglottis. Therefore, it is important to determine the mechanisms and prevention of sudden death in MSA. METHODS: We reviewed the literature on the mechanisms and prevention of sudden death in patients with MSA. RESULTS: Sudden death in MSA is hypothesized to be a consequence of disordered central respiration, suffocation caused by sputum and food, upper airway obstruction from NPPV acting on a floppy epiglottis, cardiac autonomic disturbance, or a combination of these factors. CONCLUSION: Various factors may be involved in the mechanism of sudden death in MSA. A multidisciplinary approach is needed to prevent sudden death, and this requires an organized system of several medical specialties. Neurologists require a cooperative network that includes experts in otorhinolaryngology, sleep medicine, dysphagia rehabilitation, and cardiology.

Laryngeal stridor in multiple system atrophy: Clinicopathological features and causal hypotheses.

Laryngeal stridor is recognized as a characteristic clinical manifestation in patients with multiple system atrophy (MSA). However, the pathogenic mechanisms underlying this symptom are controversial. Neurogenic atrophy of the posterior cricoarytenoid muscle has been identified in cases of MSA, suggesting that laryngeal abductor weakness contributes to laryngeal stridor. However, dystonia in the laryngeal adductor muscles has also been reported to cause laryngeal stridor. Depletion of serotonergic neurons in the medullary raphe nuclei, which exert tonic drive to activate the posterior cricoarytenoid muscle, has recently been identified in MSA cases. This adds weight to the possibility that laryngeal abductor weakness underlies laryngeal stridor in MSA. Continuous positive airway pressure therapy is currently used in the treatment of laryngeal stridor, but should be used with caution in patients showing contraindications. Current knowledge of the clinical and neuropathological features of laryngeal stridor is summarized in this paper, and the hypothesized causes and possible therapeutic options for this symptom are discussed.

Risk Factors and Clinical Outcomes of Recurrent Laryngeal Nerve Paralysis After Esophagectomy for Thoracic Esophageal Carcinoma.

BACKGROUND: The objectives of this study were to assess the incidence of recurrent laryngeal nerve paralysis (RLNP) using laryngoscopy after esophagectomy for thoracic esophageal carcinoma and to clarify the risk factors influencing postoperative RLNP. METHODS: A total of 299 patients who underwent laryngoscopic examination after esophagectomy were retrospectively reviewed. Patients who were found to have postoperative RLNP were followed up every 1­3 months, with a median follow-up period of 3 months. Recovery from paralysis was also evaluated on the basis of each affected nerve. Multivariate analyses using logistic regression were used to identify independent risk factors for RLNP. Cumulative recovery rate was calculated using Kaplan­Meier method. RESULTS: A total of 178 (59.5%) patients were diagnosed with RLNP by first laryngoscopy [bilateral in 59 (33.1%) patients, right in 15 (8.4%), and left in 104 (58.4%)]. In 206 patients who underwent transthoracic and thoracoscopic esophagectomy, independent risk factors for RLNP were lymph node dissection along the right RLN (odds ratio [OR] 3.01, 95% confidence interval [CI] 1.06­8.54, P = 0.04) and cervical anastomosis (OR 5.94, 95% CI 1.78­19.80, P < 0.01). Cumulative recovery rate from RLNP was 61.7% at 12 months after esophagectomy with 91 nerves eventually recovering from paralysis. Median recovery time was 6 months. CONCLUSIONS: RLNP developed in 60 % of patients after esophagectomy and may be associated with lymphadenectomy around the right RLN and cervical esophageal mobilization. Although 62% of affected nerves recovered within 12 months, great attention should be given when performing these procedures.

Discontinuation of continuous positive airway pressure treatment in multiple system atrophy.

OBJECTIVE: Continuous positive airway pressure (CPAP) is used for the management of sleep-disordered breathing in patients with multiple system atrophy (MSA). However, the long-term outcome after CPAP treatment is yet to be ascertained. METHODS: A retrospective study was performed to investigate the frequency and causes of CPAP treatment discontinuation, and to ascertain the determinations of CPAP treatment duration in Japanese patients diagnosed with probable MSA based upon the consensus diagnostic criteria, who were admitted to our hospital from 2001 to 2012. RESULTS: Twenty-nine consecutive patients treated with CPAP were analyzed. During the observation period, 19 patients (66%) discontinued CPAP treatment. The median CPAP treatment duration was 13.0 months (range, 1-53 months). The major causes for discontinuation were pulmonary infection, respiratory insufficiency of undetermined origin, and CPAP intolerance. On comparing the clinical characteristics of the groups subjected to short- and long-term CPAP treatment, floppy epiglottis was more frequently observed in the short-term group than in the long-term group (64% vs. 15%; P = 0.015). CONCLUSION: The CPAP treatment duration in MSA patients was not long, and floppy epiglottis may be a determinant of the duration of CPAP treatment.

Mild noise-induced hearing loss at young age affects temporal modulation transfer functions in adult cat primary auditory cortex.

Kittens were exposed for 2h to a 1/3rd octave band of noise centered at 5kHz and at 120dB SPL. After the exposure, they were kept in a quiet room for at least 4 weeks, and until they were mature. The noise-exposed cats showed on average 16.5dB higher ABR thresholds and 13.2dB higher thresholds at the characteristic frequency (CF) than the control cats for frequencies between 4 and 16kHz. The frequency-tuning curve bandwidth at 20dB above threshold was significantly increased compared to controls in the CF region of the hearing loss. In noise-exposed cats, temporal modulation-transfer functions (tMTFs) to amplitude-modulated (AM) noise, but not to periodic click trains, showed a marked increase for modulation frequencies (MFs) below 6Hz. The vectorstrength in noise-exposed cats increased for all modulation frequencies below 32Hz for neurons with a CF in the range of the hearing loss. The tMTFs for AMnoise in the noise-exposed group were less band-pass compared to the controls, and in that sense the mild hearing loss could be considered as effectively reducing the central activation in the same way as a reduced sound pressure level. Effects of reduced central inhibition are visible in the broadening of frequency-tuning curves, and in the increased limiting rates for AMnoise.

Spectrally enhanced acoustic environment disrupts frequency representation in cat auditory cortex.

Sensory environments are known to shape nervous system organization. Here we show that passive long-term exposure to a spectrally enhanced acoustic environment (EAE) causes reorganization of the tonotopic map in juvenile cat auditory cortex without inducing any hearing loss. The EAE consisted of tone pips of 32 different frequencies (5-20 kHz), presented in random order at an average rate of 96 Hz. The EAE caused a strong reduction of the representation of EAE frequencies and an over-representation of frequencies neighboring those of the EAE. This is in sharp contrast with earlier developmental studies showing an enlargement of the cortical representation of EAEs consisting of a narrow frequency band. We observed fewer than normal appropriately tuned short-latency responses to EAE frequencies, together with more common long-latency responses tuned to EAE-neighboring frequencies.

Effects of noise-induced hearing loss at young age on voice onset time and gap-in-noise representations in adult cat primary auditory cortex.

Here we show that mild hearing loss induced by noise exposure in early age causes a decrease in neural temporal resolution when measured in adulthood. We investigated the effect of this chronic hearing loss on the representation of a voice onset time (VOT) and a gap-duration continuum in primary auditory cortex (AI) in cats, which were exposed at the age of 6 weeks to a 120-dB SPL, 5-kHz 1/3 octave noise band for 2 h. The resulting hearing loss measured using auditory brainstem responses and cortical multiunit thresholds at 4-6 months of age was 20-40 dB between 1 and 32 kHz. Multiple single-unit activity was recorded in seven noise-exposed cats and nine control cats related to the presentation of a/ba/-/pa/ continuum in which VOT was varied in 5-ms step from 0 to 70 ms. We also obtained data for noise bursts with gaps, of duration equal to the VOT, embedded in noise 5 ms after the onset. Both stimuli were presented at 65 dB SPL. Minimum VOT and early-gap duration were defined as the lowest value in which an on-response, significantly above the spontaneous activity, to both the leading and trailing noise bursts or vowel was obtained. The mild chronic noise-induced hearing loss increased the minimum detectable VOT and gap duration by 10 ms. We also analyzed the maximum firing rate (FRmax) and the latency of the responses as a function of VOT and gap duration and found a significant reduction in the FRmax to the trailing noise burst for gap durations above 50 ms. This suggests that mild hearing loss acquired in early age may affect cortical temporal processing in adulthood.