Infiltrative fibrous lesion of the facial nerve mimicking a facial nerve tumor.

PURPOSE: To report three cases of facial nerve lesions that were clinically expected to be facial nerve tumors but showed fibrotic infiltration without any apparent signs of a specific tumor on histopathological findings. We also aimed to investigate the clinical characteristics of these cases. METHODS: Medical records of patients who underwent surgery for facial nerve lesions were reviewed. RESULTS: All three cases initially had House-Brackmann (HB) grade IV-V facial nerve palsy. On radiological imaging, schwannoma or glomus tumor originating from the facial nerve was suspected. All patients underwent complete surgical removal of the neoplasm followed by facial nerve reconstruction using the sural nerve. The lesions were histologically confirmed as infiltrative fibrous lesions without tumor cells. In two cases, facial nerve palsy improved to HB grade III by nine months post-surgery, and there were no signs of recurrence on follow-up MRI. The other case, after 1 year of follow-up, showed persistence of HB grade V facial nerve palsy without any evidence of recurrence. CONCLUSION: Fibrotic lesions of the facial nerve could mimic primary facial nerve tumors. Clinicians should consider this condition even when a facial nerve tumor is suspected.

Clinical outcome and prognostic factors in adenoid cystic carcinoma of the external auditory canal: proposal for a refined T-stage classification system.

PURPOSE: Although adenoid cystic carcinoma (ACC) of the external auditory canal (EAC) has a different pathophysiology from squamous cell carcinoma, the same staging system is used. The aim of this study was to propose a refined staging system, which is more suitable for ACC of the EAC. METHODS: A total of 25 patients who were diagnosed with ACC of the EAC were reviewed. The modified Pittsburgh staging system (mPSS) that is universally used for temporal bone malignancy was refined for ACC (rPSS). The limited (< 0.5 cm) lateral soft tissue involvement was classified as T1 and extensive (≥ 0.5 cm) lateral soft tissue involvement as T2. The disease-free survival rate (DFSR) was assessed in the patients who underwent surgical treatment according to two staging systems; mPSS and rPSS. RESULTS: When staging using mPSS, most patients (96.0%, n = 24) were classified as T4. However, when rPSS was used, T1, T2, T3, and T4 stage occupied 36.0% (n = 9), 40.0% (n = 10), 12.0% (n = 3), 12.0% (n = 3), respectively. There was no difference in DFSR according to the T stage using mPSS (p = 0.466). However, when rPSS was used, the DFSR showed significant correlation with the T stage (p = 0.032). CONCLUSIONS: Clinical T stage of mPSS was not sufficient to predict survival rate in ACC of the EAC, and we propose that the information on the lateral soft tissue involvement needs to be added to the existing staging system.

Vestibular mapping in Ramsay-Hunt syndrome and idiopathic sudden sensorineural hearing loss.

PURPOSE: To observe vestibular impairment patterns in patients with Ramsay Hunt syndrome with dizziness (RHS_D) and sudden sensorineural hearing loss with dizziness (SSNHL_D) using hierarchical cluster analysis (HCA) to interpret results with possible mechanisms. METHODS: The data of 30 RHS_D and 81 SSNHL_D patients from January 2017 to August 2022 in a single tertiary referral center were retrospectively analyzed. Video head impulse test (vHIT) and vestibular evoked myogenic potential (VEMP) were used for vestibular analysis of peripheral vestibular organs, and the results of vHIT and VEMP were analyzed. HCA was used to analyze vestibular impairment patterns. RESULTS: In RHS_D patients, the lateral semicircular canal (LSCC) was the most impaired semicircular canal (SCC), followed by the anterior semicircular canal (ASCC) and the posterior semicircular canal (PSCC), and the utricle was more impaired than the saccule. In SSNHL_D patients, the PSCC was the most impaired SCC, followed by the LSCC and the ASCC, and the utricle was more impaired than the saccule. In HCA of RHS_D patients, the ASCC and utricle were initially clustered, followed by the LSCC, PSCC and saccule in order. In the HCA of SSNHL_D patients, the PSCC was solely merged and independently clustered. CONCLUSION: There were different patterns of vestibular impairments between RHS_D and SSNHL_D patients. The vestibular analysis and HCA results of SSNHL_D showed tendency of skip lesion, which could be explained by vascular pathophysiology.

Effect of Intermittent Hypoxia on Metabolic Syndrome and Insulin Resistance in the General Male Population.

Background and objectives: Obstructive sleep apnea (OSA) is closely associated with insulin resistance (IR) and is an independent risk factor for incident type 2 diabetes mellitus (T2DM). Most studies evaluate the correlation between OSA and IR in only obese or T2DM patients. Therefore, we tried to investigate the effect of OSA on metabolic syndrome and IR in the general healthy male population. Materials and Methods: 184 subjects who visited a preventive health examination program were recruited for this study. All subjects received overnight polysomnography by a portable device (Watch-PAT 200). We examined several metabolic parameters and a homeostasis model of assessment for insulin resistance index (HOMA-IR). The subjects were divided into three groups by AHI (Apnea-hyponea index): normal group (AHI < 5), mild OSA group (5 ≤ AHI < 15), and moderate-severe OSA group (AHI ≥ 15). They were also divided into two groups according to minimum oxygen saturation: low group, Min-SpO2 < 88%; and high group, Min-SpO2 ≥ 88%. Results: Parameters of metabolic syndrome, including waist circumference, systolic and diastolic blood pressure, triglyceride, and high-density lipoprotein cholesterol showed significant differences among the AHI groups. Furthermore, HOMA-IR showed significant differences among the AHI groups. Those parameters, including metabolic syndrome and HOMA-IR, also showed differences between Min-SpO2 groups. Conclusions: In summary, this study helps confirm that AHI is associated with HOMA-IR in the general male population. Furthermore, the severity of AHI correlated with the parameters of metabolic syndrome. Therefore, AHI might be an indicator for evaluating both T2DM and metabolic syndrome, even in the general male population.

Bioresorbable silicon electronics for transient spatiotemporal mapping of electrical activity from the cerebral cortex.

Bioresorbable silicon electronics technology offers unprecedented opportunities to deploy advanced implantable monitoring systems that eliminate risks, cost and discomfort associated with surgical extraction. Applications include postoperative monitoring and transient physiologic recording after percutaneous or minimally invasive placement of vascular, cardiac, orthopaedic, neural or other devices. We present an embodiment of these materials in both passive and actively addressed arrays of bioresorbable silicon electrodes with multiplexing capabilities, which record in vivo electrophysiological signals from the cortical surface and the subgaleal space. The devices detect normal physiologic and epileptiform activity, both in acute and chronic recordings. Comparative studies show sensor performance comparable to standard clinical systems and reduced tissue reactivity relative to conventional clinical electrocorticography (ECoG) electrodes. This technology offers general applicability in neural interfaces, with additional potential utility in treatment of disorders where transient monitoring and modulation of physiologic function, implant integrity and tissue recovery or regeneration are required.

A Comparative Study Using Vestibular Mapping in Sudden Sensorineural Hearing Loss With and Without Vertigo.

OBJECTIVE: To investigate the impairment patterns in peripheral vestibular organs in sudden sensorineural hearing loss (SSNHL) with and without vertigo. STUDY DESIGN: Retrospective study. SETTING: Single tertiary medical center. METHODS: Data from 165 SSNHL patients in a tertiary referral center from January 2017 to December 2022 were retrospectively analyzed. All patients underwent a video head impulse test, vestibular evoked myogenic potential test, and pure-tone audiometry. Hierarchical cluster analysis was performed to investigate vestibular impairment patterns. The prognosis of the hearing was determined using American Academy of Otolaryngology-Head and Neck Surgery recommendations. RESULTS: After excluding patients with vestibular schwannoma and Meniere's disease, 152 patients were included in this study. A total of 73 of 152 patients were categorized as SSNHL with vertigo (SSNHL_V) and showed an independent merge of the posterior semicircular canal (PSCC) in cluster analysis. A total of 79 of 152 patients were categorized as SSNHL without vertigo (SSNHL_N) and showed an independent merge of saccule in cluster analysis. The PSCC (56.2%) and saccule (20.3%) were the most frequently impaired vestibular organs in SSNHL_V and SSNHL_N, respectively. In terms of prognosis, 106 of 152 patients had partial/no recovery and showed an independent merge of the PSCC in cluster analysis. A total of 46 of 152 patients had a complete recovery and showed an independent merge of the saccule in cluster analysis. CONCLUSION: A tendency of isolated PSCC dysfunction was seen in SSNHL_V and partial/no recovery. A tendency of isolated saccular dysfunction was seen in SSNHL_N and complete recovery. Different treatments might be needed in SSNHL depending on the presence of vertigo.

Real-World Effectiveness of Wearable Augmented Reality Device for Patients With Hearing Loss: Prospective Study.

BACKGROUND: Hearing loss limits communication and social activity, and hearing aids (HAs) are an efficient rehabilitative option for improving oral communication and speech comprehension, as well as the psychosocial comfort of people with hearing loss. To overcome this problem, over-the-counter amplification devices including personal sound amplification products and wearable augmented reality devices (WARDs) have been introduced. OBJECTIVE: This study aimed to evaluate the clinical effectiveness of WARDs for patients with mild to moderate hearing loss. METHODS: A total of 40 patients (18 men and 22 women) with mild to moderate hearing loss were enrolled prospectively in this study. All participants were instructed to wear a WARD, Galaxy Buds Pro (Samsung Electronics), at least 4 hours a day for 2 weeks, for amplifying ambient sounds. Questionnaires including the Korean version of the abbreviated profile of hearing aid benefit (K-APHAB) and the Korean adaptation of the international outcome inventory for hearing aids (K-IOI-HA) were used to assess personal satisfaction in all participants. Audiologic tests, including sound field audiometry, sound field word recognition score (WRS), and the Korean version of hearing in noise test (K-HINT), were administered to 14 of 40 patients. The tests were performed under two conditions: unaided and aided with WARDs. RESULTS: The mean age of the participants was 55.4 (SD 10.7) years. After 2 weeks of the field trial, participants demonstrated a benefit of WARDs on the K-APHAB. Scores of 3 subscales of ease of communication, reverberation, and background noise were improved significantly (P<.001). However, scores regarding aversiveness were worse under the aided condition (P<.001). K-IOI-HA findings indicated high user satisfaction after the 2-week field trial. On audiologic evaluation, the K-HINT did not show significant differences between unaided and aided conditions (P=.97). However, the hearing threshold on sound field audiometry (P=.001) and the WRS (P=.002) showed significant improvements under the aided condition. CONCLUSIONS: WARDs can be beneficial for patients with mild to moderate hearing loss as a cost-effective alternative to conventional hearing aids.

Importance of Video Head Impulse Test Parameters for Recovery of Symptoms in Acute Vestibular Neuritis.

OBJECTIVE: To examine the importance of video head impulse test parameter for recovery of symptoms in acute vestibular neuritis (AVN). STUDY DESIGN: Prospective study. SETTING: Tertiary referral hospital. PATIENTS/INTERVENTIONS: Twenty-seven patients with AVN were enrolled. We divided patients into two groups according to both dizziness handicap inventory (DHI) score and visual analog scale (VAS) at 6 months: Group F (symptoms free), DHI = 0 and VAS = 0; Group R (symptoms residual), DHI more than zero or VAS more than zero. MAIN OUTCOME MEASURE: All patients underwent video head impulse test paradigm (HIMP), and suppression head impulse test paradigm (SHIMP) initially and at 1 month. Patients were also asked to complete DHI and VAS initially, at 1 month and 6 months. We compared measured parameters between Group F and R. RESULTS: In HIMP, Group F showed higher vestibular-ocular reflex (VOR) gain, higher occurrence of covert corrective saccade (CS), lower occurrence and peak velocity of overt CS, and lower PR score than Group R at 1 month. In SHIMP, Group F showed higher VOR gain, higher occurrence and peak velocity of anti-CS, and higher PR score than Group R at 1 month. CONCLUSIONS: Above parameters of both HIMP and SHIMP at 1 month would be important factors to predict the residual symptoms in chronic phase of AVN.

Effect of Aging and Direction of Impulse in Suppression Head Impulse Test.

OBJECTIVE: To identify differences in the vestibulo-ocular reflex (VOR) gain value and the peak saccade velocity in the suppression video head impulse test paradigms according to the age of the subject and the direction of the impulse. STUDY DESIGN: Retrospective chart analysis. SETTING: Tertiary referral hospital. PATIENTS/INTERVENTIONS: Between October 2017 and May 2019, we enrolled subjects who had previous histories of dizziness but no dizziness over the last 1 month. MAIN OUTCOME MEASURE: We conducted cervical vestibular-evoked myogenic potential and caloric tests, as well as video head impulse tests. We excluded the subjects who had abnormal cervical vestibular-evoked myogenic potential results (asymmetry ratio of greater than 30%) and abnormal caloric test results (caloric paresis of greater than 25%). RESULTS: We included 647 subjects aged 10 to 87 years. The mean VOR gain and peak saccade velocity were maintained in subjects less than 70 years old (VOR gain, 0.991 ±â€Š0.08, peak saccade velocity, 348.47 ±â€Š142.32). However, the decreases in VOR gain and peak saccade velocity were significant in subjects over 70 years old (VOR gain, 0.928 ±â€Š0.09, peak saccade velocity, 315.51 ±â€Š0.09; p < 0.001). The mean VOR gain of the rightward impulse (1.00 ±â€Š0.09) was higher than the leftward impulse (0.96 ±â€Š0.08, p < 0.001). CONCLUSIONS: Both the VOR gain and peak saccade velocity of suppression video head impulse test paradigms declined with increasing age over 70 years. In addition, the VOR gain of the rightward impulse was higher than the leftward impulse in the right-eye recordings.

Change of VOR gain and pure-tone threshold after single low-dose intratympanic gentamicin injection in Meniere's disease.

Background: Intratympanic gentamicin injection (ITG) is a well-accepted means to treat intractable Meniere's disease (MD).Aims/Objectives: To investigate change of vestibule-ocular reflex (VOR) gain and pure-tone threshold after low-dose ITG for MD.Methods: Sixteen patients with definite MD who were treated by low-dose ITG were retrospectively reviewed. We defined VOR gain difference as an amount of decreased gain in video head impulse test one month after ITG. Patients were classified into two groups: single injection vs. multiple injections. Multiple injections group was composed of patients with poor vertigo control after initial ITG who required second or third ITG later in follow up period.Results: VOR gain differences of both horizontal and posterior canal plane were higher than those of anterior canal plane. Between two groups, mean VOR gain difference of horizontal canal plane in multiple injections group was lower than that in single injection group. Only two patients showed increased pure-tone threshold more than 10 dB.Conclusion and significance: Our results suggest that ITG appears to cause a differential loss of function across three semicircular canals. Furthermore, if VOR gain difference of horizontal canal is relatively low after initial ITG, patient might have poor vertigo control and be required another ITG.

Vestibular function analysis of sudden sensorineural hearing loss with dizziness.

BACKGROUND: A considerable number of patients with sudden sensorineural hearing loss (SSNHL) have been reported to have dizziness. OBJECTIVE: To analyze vestibular functions and identify the clinical characteristics of SSNHL with dizzinessMETHODS:71 patients with SSNHL who complained of dizziness were investigated retrospectively. The patients underwent vestibular function tests consisting of video-nystagmography, video head impulse test and vestibular evoked myogenic potentials. RESULTS: Among 35 patients with spontaneous nystagmus (SN), 21 showed ipsilesional posterior canal gain deficit, 11 showed a gain deficit in the posterior canal only and 9 showed both horizontal and posterior canal gain deficit in video head impulse test. In only one subject with bilateral horizontal canal gain deficit with contralesional SN, AICA infarction was observed.Among 36 patients without SN, 10 were diagnosed as benign paroxysmal positional vertigo and 5 had ipsilesional canal paresis in caloric test. Other 21 patients showed no abnormal signs in vestibular function tests. CONCLUSIONS: In VFT analysis of SSNHL with dizziness, diverse patterns were identified. In the absence of SN, no definite vestibular organ involvement was the most frequent. But in the case with SN, posterior canal deficit was most common and cerebellar ischemic stroke was rare.

Comparing the Suppression Head Impulse Paradigm and the Head Impulse Paradigm in Vestibular Neuritis.

OBJECTIVE: To compare the results of suppression head impulse paradigm (SHIMP) and head impulse paradigm (HIMP) in acute vestibular neuritis (AVN). STUDY DESIGN: Retrospective study. SETTING: Tertiary otology clinic. PATIENTS AND INTERVENTIONS: We tested 21 patients with AVN with the HIMP, SHIMP, and caloric tests, and we analyzed the relationships between the tests' results. MAIN OUTCOME MEASURES: For this study, we adopted vestibulo-ocular reflex (VOR) gains in the SHIMP and HIMP, peak saccade velocity (PSV) of SHIMP which is another indicator of residual vestibular function, and canal paresis of caloric test. RESULTS: VOR gains showed significant correlation (R = 0.926, p < 0.001) between the SHIMP and HIMP, but VOR gains were slightly lower in the SHIMP than in the HIMP (mean difference 0.07 ±â€Š0.09, p < 0.001). The difference between the HIMP and SHIMP gains was slightly larger on the affected side (0.10 ±â€Š0.09) than on the healthy side (0.03 ±â€Š0.09). The PSV of SHIMP had significant correlation with HIMP gain and canal paresis. Sixteen of 21 patients showed 100% ipsilesional caloric canal paresis, and eight (50%) of them showed no anti-compensatory saccade (direction toward head rotation) in the SHIMP. However, they showed not extremely low VOR gain but variable VOR gain. CONCLUSION: The new parameters of SHIMP might be used as complement for evaluating vestibular function in AVN. However, the clinical impact of the saccades of SHIMP in AVN has not been revealed clearly yet. This question should be investigated in further studies.

Clinical Characteristics of Acute Vestibular Neuritis According to Involvement Site.

OBJECTIVE: To analyze the clinical characteristics of acute vestibular neuritis (AVN) according to involvement site. STUDY DESIGN: Retrospective chart analysis. SETTING: Tertiary referral hospital. PATIENTS/INTERVENTIONS: Over a period of 3 years, we reviewed 133 cases of AVN. Patients were classified into three groups: 1) total vestibular neuritis (superior and inferior vestibular nerve involvement [TVN]); 2) superior vestibular neuritis (superior vestibular nerve involvement [SVN]); and 3) inferior vestibular neuritis (inferior vestibular nerve involvement [IVN]). MAIN OUTCOME MEASURE: We analyzed the clinical course and results of vestibular function tests (video-nystagmography, video head impulse test [vHIT], caloric test, and cervical vestibular evoked myogenic potential). RESULTS: In the study, there were 39.9% TVN cases, 48.1% SVN cases, and 12% IVN cases. The number of days to spontaneous nystagmus remission, hospital duration, and follow-up period were shorter in the IVN group than in the SVN and TVN groups. The symptom onset period was longer in the IVN group than in the SVN and TVN groups. Spontaneous nystagmus and head shaking nystagmus amplitude were smaller in the IVN group than in the SVN and TVN groups. Concordance of results between the caloric test, cervical vestibular evoked myogenic potential, and vHIT was relatively low in the IVN group. CONCLUSION: The IVN group had a shorter clinical course and weaker nystagmus in comparison with the TVN and SVN groups. The use of additional vHIT in the diagnosis of AVN can help provide a more accurate diagnosis of the rare subtype of IVN, which can be confused with various central lesions.

Peripheral Vestibulopathy Presenting as Acute Vertigo and Spontaneous Nystagmus with Negative Video Head Impulse Test.

OBJECTIVE: To analyze acute vertigo showing spontaneous nystagmus with negative video head impulse test (vHIT). STUDY DESIGN: Retrospective chart analysis. SETTING: Tertiary referral hospital. SUBJECTS AND METHODS: Over 16 months, 155 patients were identified with acute vertigo with spontaneous nystagmus. Of these 155, 30 (19.4%) were enrolled in this study because they did not show gain loss or catch-up saccades in both sides of the horizontal vHIT. Results of vestibular function tests (videonystagmography, horizontal vHIT, caloric test, and cervical vestibular-evoked myogenic potential [cVEMP]) and pure tone audiometry were analyzed. For all cases, magnetic resonance imaging with diffusion-weighted imaging was checked. RESULTS: Patients consisted of 17 with Ménière's disease and 7 with sudden sensorineural hearing loss with vertigo (SSNHL_V), and only 3 patients were finally diagnosed as having acute vascular stroke. Except for the loss of hearing on the lesion side, the direction of nystagmus or cVEMP asymmetry showed very different results. All 7 patients with SSNHL_V did not have canal paresis in the caloric test, but cVEMP amplitude was smaller on the lesion side for 6 patients. CONCLUSIONS: For patients with acute vertigo presenting spontaneous nystagmus with negative horizontal vHIT, it is important not only to focus on the diagnosis of acute vascular stroke but also to evaluate hearing because of the high possibility of Ménière's disease or SSNHL_V.

Two dissociation pathways of water and ammonia on the Si(001) surface.

Using first-principles density-functional calculations, we investigated two competing pathways for the dissociation of water and ammonia on a Si(001) surface. For both systems, we found that, in addition to the conventionally accepted intradimer transfer of the H atom, the interdimer transfer of the H atom can be equally probable with the same reaction mechanism. Our analysis shows that the two dissociation pathways occur through the Lewis acid-base reaction between the partially positive H ion and the electron-abundant up atom of the buckled Si dimer. The result of the interdimer H transfer not only supports a recently proposed model for C-defect on Si(001) but also corresponds to the recent scanning tunneling microscopy data of ammonia dissociation on Si(001).

Availability of preoperative systemic steroids on endoscopic sinus surgery for chronic rhinosinusitis with nasal polyposis.

PURPOSE: To analyze the outcome of endoscopic sinus surgery (ESS) after preoperative systemic steroid (PSS) treatment for chronic rhinosinusitis (CRS) with nasal polyposis (NP) and to investigate and compare clinicopathological factors associated with the outcome. MATERIALS AND METHODS: We performed a retrospective chart review of 468 patients with CRS with NP who underwent primary ESS between January 2005 and October 2011. 124 patients who met the inclusion criteria were included. Beginning from 2008, our clinic administered steroid preoperatively in patients of CRS with NP, thus there were 84 patients with preoperative systemic steroid (PSS group) and another 40 patients without such regimen (no PSS group). To evaluate the outcome after ESS, poor outcome and complication were analyzed according to the following parameters: age, sex, follow-up duration, eosinophilic infiltration, atopy, asthma, Lund-Mackay score, and polyp grade. RESULTS: There was no significant difference in poor outcome rates between the PSS and no PSS group (35.0% vs. 47.6%, p=0.185). There was no significant difference in complication rates between the PSS and no PSS group (10% vs. 6%, p=0.468). As with the multivariate analysis of the clinicopathological factors to the poor outcome rate, presence of asthma and eosinophilic infiltration were significantly related (odds ratio as 6.555 and 4.505, respectively), whereas PSS was confirmed as less likely related (odds ratio 0.611). CONCLUSION: Low dose PSS administration does not seem to have an effect on the outcome after ESS in patients who have CRS with NP. Eosinophilic infiltration and presence of asthma are important predictors of surgical outcome.

Self-directed growth of benzonitrile line on H-terminated Si(001) surface.

Using first-principles density-functional calculations we predict a self-directed growth of benzonitrile molecular line on a H-terminated Si(001) surface. The C[triple bond]N bond of benzonitrile reacts with a single Si dangling bond which can be generated by the removal of a H atom, forming one Si-N bond and one C radical. Subsequently, the produced C radical can be stabilized by abstracting a H atom from a neighboring Si dimer, creating another H-empty site. This H-abstraction process whose activation barrier is 0.65 eV sets off a chain reaction to grow one-dimensional benzonitrile line along the Si dimer row. Our calculated energy profile for formation of the benzonitrile line shows its relatively easier formation compared with previously reported styrene and vinylferrocene lines.