Long-term follow-up results of facial nerve schwannoma with good facial nerve function: a multicenter study.

PURPOSE: Facial nerve schwannomas (FNSs) are rare intracranial tumors, and the optimal management of these tumors remains unclear. We investigated the long-term follow-up results of FNS with good facial nerve function. METHODS: At nine medical centers in the Korean Facial Nerve Study Group, 43 patients undergoing observation periods longer than 12 months for FNS with good facial nerve function (House-Brackmann grade ≤ II) were enrolled, and clinical and radiographic data were obtained for these cases. RESULTS: The mean follow-up period was 63 months. In the majority of cases, tumors involved multiple segments (81.4%) and only eight cases were confined to a single site. There were no cases where the tumor was confined to the extratemporal region. Tumor size increased slightly, with an average estimated change of 0.48 mm/year. Twenty (46.5%) of 43 patients showed no change in tumor size. Seven patients (16.3%) showed worsening House-Brackmann (H-B) grade, of which two patients deteriorated from H-B grade I to II, four worsened to grade III, and one deteriorated to grade IV. The remaining 36 patients (83.7%) showed no change in facial nerve function. There was no difference in H-B grade according to tumor size at the time of diagnosis or change in tumor size. CONCLUSION: We conducted a large-scale observational study of FNS with good facial nerve function. Our study showed that many patients maintained facial nerve function during long-term follow-up. Conservative management with regular examination and imaging can be an appropriate option for managing FNS with good facial nerve function.

Bilateral Orbital Apex Syndrome Related to Sphenoid Fungal Sinusitis.

Orbital apex syndrome (OAS) is a rare condition that usually occurs due to damage to surrounding inner and surrounding bone tissue. Orbital apex syndrome may result from a variety of conditions that cause damage to the superior orbital fissure and to the optic canal leading to optic nerve (II) dysfunction. We recently experienced a rare case of sphenoidal Aspergillosis, which damaged the adjacent cavernous sinus structures and led to the definite symptom of bilateral OAS in a 77-year-old male. We present this rare case with a brief review of these disease's entities.

Factors Affecting the Extrusion Rate and Complications After Ventilation Tube Insertion: A Multicenter Registry Study on the Effectiveness of Ventilation Tube Insertion in Pediatric Patients With Chronic Otitis Media With Effusion-Part II.

OBJECTIVES: The impacts of ventilation tube (VT) type and effusion composition on the VT extrusion rate and complications in children with otitis media remain unclear. This part II study evaluated the factors affecting the extrusion rate, recurrence rate, and complications of VT insertion. METHODS: A prospective study was conducted between June 2014 and December 2016 (the EVENT study [analysis of the effectiveness of ventilation tube insertion in pediatric patients with chronic otitis media]), with follow-up data collected until the end of 2017. Patients aged <15 years diagnosed with otitis media with effusion who received VT insertion were recruited at 15 tertiary hospitals. The primary outcomes were time to extrusion of VT, time to effusion recurrence, and complications. RESULTS: Data from 401 patients were analyzed. After excluding the. RESULTS: of long-lasting tubes (Paparella type II and T-tubes), silicone tubes (Paparella type I) exhibited a significantly longer extended time to extrusion (mean, 400 days) than titanium tubes (collar-button-type 1.0 mm: mean, 312 days; P<0.001). VT material (hazard ratio [HR], 2.117, 95% confidence interval [CI], 1.254-3.572; P=0.005), age (HR, 3.949; 95% CI, 1.239-12.590; P=0.02), and effusion composition (P=0.005) were significantly associated with the time to recurrence of middle ear effusion. Ears with purulent (mean, 567 days) and glue-like (mean, 588 days) effusions exhibited a shorter time to recurrence than ears with serous (mean, 846 days) or mucoid (mean, 925 days) effusions. The revision VT rates during follow-up were 3.5%, 15.5%, 10.4%, and 38.9% in ears with serous, mucoid, glue-like, and purulent effusions, respectively (P<0.001). The revision surgery rates were higher among patients aged <7 years than among those aged ≥7 years. CONCLUSION: Silicone tubes (Paparella type I) were less prone to early extrusion than titanium 1.0 mm tubes. VT type, patient age, and effusion composition affected the time to recurrence of effusion.

The Effect of Galvanic Vestibular Stimulation on Visuospatial Cognition in an Incomplete Bilateral Vestibular Deafferentation Mouse Model.

Objectives: To evaluate the efficacy of galvanic vestibular stimulation (GVS) for recovering from the locomotor and spatial memory deficits of a murine bilateral vestibular deafferentation (BVD) model. Methods: Male C57BL/6 mice (n = 36) were assigned to three groups: bilateral labyrinthectomy with (BVD_GVS group) and without (BVD_non-GVS group) the GVS intervention, and a control group with the sham operation. We used the open field and Y maze, and Morris water maze (MWM) tests to assess locomotor and visuospatial cognitive performance before (baseline) and 3, 7, and 14 days after surgical bilateral labyrinthectomy. For the GVS group, a sinusoidal current at the frequency at 1 Hz and amplitude 0.1 mA was delivered for 30 min daily from the postoperative day (POD) 0 to 4 via electrodes inserted subcutaneously close to both the bony labyrinths. Results: Short-term spatial memory was significantly impaired in bilaterally labyrinthectomized mice (BVD_non-GVS group), as reflected by decreased spontaneous alternation performance in the place recognition test and time spent in the novel arm and increased same arm return in the Y-maze test, compared with the control. Long-term spatial memory was also impaired, as indicated by a longer escape latency in the hidden platform trial and a lower percentage of time spent in the target quadrant in the probe trial of the MWM. GVS application significantly accelerated the recovery of locomotion and short-term and long-term spatial memory deficits in the BVD mice. Conclusions: Our data demonstrate that locomotion, short-term, and long-term (at least 2 weeks) spatial memory were impaired in BVD mice. The early administration of sinusoidal GVS accelerated the recovery of those locomotion and spatial memory deficiencies. GVS could be applied to patients with BVD to improve their locomotion and vestibular cognitive functioning.

The Differential Effects of Acute Right- vs. Left-Sided Vestibular Deafferentation on Spatial Cognition in Unilateral Labyrinthectomized Mice.

This study aimed to investigate the disparity in locomotor and spatial memory deficits caused by left- or right-sided unilateral vestibular deafferentation (UVD) using a mouse model of unilateral labyrinthectomy (UL) and to examine the effects of galvanic vestibular stimulation (GVS) on the deficits over 14 days. Five experimental groups were established: the left-sided and right-sided UL (Lt.-UL and Rt.-UL) groups, left-sided and right-sided UL with bipolar GVS with the cathode on the lesion side (Lt.-GVS and Rt.-GVS) groups, and a control group with sham surgery. We assessed the locomotor and cognitive-behavioral functions using the open field (OF), Y maze, and Morris water maze (MWM) tests before (baseline) and 3, 7, and 14 days after surgical UL in each group. On postoperative day (POD) 3, locomotion and spatial working memory were more impaired in the Lt.-UL group compared with the Rt.-UL group (p < 0.01, Tamhane test). On POD 7, there was a substantial difference between the groups; the locomotion and spatial navigation of the Lt.-UL group recovered significantly more slowly compared with those of the Rt.-UL group. Although the differences in the short-term spatial cognition and motor coordination were resolved by POD 14, the long-term spatial navigation deficits assessed by the MWM were significantly worse in the Lt.-UL group compared with the Rt.-UL group. GVS intervention accelerated the vestibular compensation in both the Lt.-GVS and Rt.-GVS groups in terms of improvement of locomotion and spatial cognition. The current data imply that right- and left-sided UVD impair spatial cognition and locomotion differently and result in different compensatory patterns. Sequential bipolar GVS when the cathode (stimulating) was assigned to the lesion side accelerated recovery for UVD-induced spatial cognition, which may have implications for managing the patients with spatial cognitive impairment, especially that induced by unilateral peripheral vestibular damage on the dominant side.

Effects of Galvanic Vestibular Stimulation on Vestibular Compensation in Unilaterally Labyrinthectomized Mice.

Objectives: To investigate the ameliorating effects of sinusoidal galvanic vestibular stimulation (GVS) on vestibular compensation from unilateral vestibular deafferentation (UVD) using a mouse model of unilateral labyrinthectomy (UL). Methods: Sixteen male C57BL/6 mice were allocated into two groups that comprise UL groups with GVS (GVS group, n = 9) and without GVS intervention (non-GVS group, n = 7). In the experimental groups, we assessed vestibulo-ocular reflex (VOR) recovery before (baseline) and at 3, 7, and 14 days after surgical unilateral labyrinthectomy. In the GVS group, stimulation was applied for 30 min daily from postoperative days (PODs) 0-4 via electrodes inserted subcutaneously next to both bony labyrinths. Results: Locomotion and VOR were significantly impaired in the non-GVS group compared to baseline. The mean VOR gain of the non-GVS group was attenuated to 0.23 at POD 3 and recovered continuously to the value of 0.54 at POD 14, but did not reach the baseline values at any frequency. GVS intervention significantly accelerated recovery of locomotion, as assessed by the amount of circling and total path length in the open field tasks compared to the non-GVS groups on PODs 3 (p < 0.001 in both amount of circling and total path length) and 7 (p < 0.01 in amount of circling and p < 0.001 in total path length, Mann-Whitney U-test). GVS also significantly improved VOR gain compared to the non-GVS groups at PODs 3 (p < 0.001), 7 (p < 0.001), and 14 (p < 0.001, independent t-tests) during sinusoidal rotations. In addition, the recovery of the phase responses and asymmetry of the VOR was significantly better in the GVS group than in the non-GVS group until 2 weeks after UVD (phase, p = 0.001; symmetry, p < 0.001 at POD 14). Conclusion: Recoveries for UVD-induced locomotion and VOR deficits were accelerated by an early intervention with GVS, which implies that GVS has the potential to improve vestibular compensation in patients with acute unilateral vestibular failure.

Galvanic Vestibular Stimulation Improves Spatial Cognition After Unilateral Labyrinthectomy in Mice.

Objectives: To investigate the deficits of spatial memory and navigation from unilateral vestibular deafferentation (UVD) and to determine the efficacy of galvanic vestibular stimulation (GVS) for recovery from these deficits using a mouse model of unilateral labyrinthectomy (UL). Methods: Thirty-six male C57BL/6 mice were allocated into three groups that comprise a control group and two experimental groups, UVD with (GVS group) and without GVS intervention (non-GVS group). In the experimental groups, we assessed the locomotor and cognitive behavioral function before (baseline) and 3, 7, and 14 days after surgical UL, using the open field (OF), Y maze, and Morris water maze (MWM) tests. In the GVS group, the stimulations were applied for 30 min daily from postoperative day (POD) 0-4 via the electrodes inserted subcutaneously close to both bony labyrinths. Results: Locomotion and spatial cognition were significantly impaired in the mice with UVD non-GVS group compared to the control group. GVS significantly accelerated recovery of locomotion compared to the control and non-GVS groups on PODs 3 (p < 0.001) and 7 (p < 0.05, Kruskal-Wallis and Mann-Whitney U tests) in the OF and Y maze tests. The mice in the GVS group were better in spatial working memory assessed with spontaneous alternation performance and spatial reference memory assessed with place recognition during the Y maze test than those in the non-GVS group on POD 3 (p < 0.001). In addition, the recovery of long-term spatial navigation deficits during the MWM, as indicated by the escape latency and the probe trial, was significantly better in the GVS group than in the non-GVS group 2 weeks after UVD (p < 0.01). Conclusions: UVD impairs spatial memory, navigation, and motor coordination. GVS accelerated recoveries in short- and long-term spatial memory and navigation, as well as locomotor function in mice with UVD, and may be applied to the patients with acute unilateral vestibular failure.

Current Treatments for Congenital Aural Atresia.

Congenital aural atresia is an ear malformation evident at birth, involving various degrees of failed external ear canal development. A true external ear canal is desirable, as devices that replace the canal are inconvenient and expensive. Therefore, an optimal surgical technique is required. Here, we review useful preoperative and operative techniques. Surgical correction is often not the preferred treatment; the hearing outcome is no better than the outcomes afforded by bone-conduction devices, and surgery may be associated with recurrence or complications such as meatal stenosis. Preoperative evaluation and appropriate management are important. Several means of preventing meatal stenosis are discussed in this review.

Primary carcinoid tumor in the external auditory canal.

A 39-year-old man visited the department of otolaryngology due to an ongoing hearing disturbance that had lasted for 1 year. Temporal bone computed tomography revealed soft tissue density nearly obliterating the left external auditory canal (EAC). The mass was composed of sheets of round tumor cells containing moderate amounts of fine granular cytoplasm and salt and pepper chromatin. Neither mitosis nor necrosis was found. The Ki-67 proliferation index was less than 2%. Cells were positive for CD56 and synaptophysin but negative for chromogranin, cytokeratin (CK) 20, and CK7. Based on these findings, the tumor was diagnosed as a carcinoid tumor, well differentiated neuroendocrine carcinoma, grade 1 (G1) according to current World Health Organization (WHO) classification of head and neck tumors; and a neuroendocrine tumor, G1 according to neuroendocrine neoplasm (NEN)-2018 WHO standard classification. He remained free of local recurrence and metastasis after 20 months of follow up. To date, only six cases of primary NENs in the EAC have been reported. Metastatic tumor should be included in the differential diagnoses. Because of its rarity, the prognosis and treatment have not yet been clarified.

Contrast in the circadian behaviors of an electrodermal activity and bioimpedance spectroscopy.

Probing the electrical response of the human body is minimally invasive and a promising area of investigation for future health care. The electrical responses of individuals may vary depending on daily physiological rhythms or environmental changes, which may hamper their prediction for pathological status. In this study, we observed circadian expressions via both alternating current (AC) and direct current (DC) electrical responses of the human body using bioelectrical impedance analysis (BIA) and electrodermal activity (EDA). In total, 14 healthy adults (9 males and 5 females) participated and were hospitalized for 2 nights with controlled caloric intake, sleep hours and residential conditions. The EDA data showed a significant circadian rhythm, but the BIA data did not show significant modulations during the measurement period. No difference was found between circadian changes in male and female participants. The acrophase of the EDA voltage response showed similar behavior with variations in the heart rate variability, with a resistance minimum occurring at approximately 4 pm, implying that the behavior of the EDA is probably affected by the sympathetic nerve response. Moreover, the resistance of the EDA varied by up to 15% from its mean value, which suggests that circadian variations cannot be neglected for the correct diagnosis of pathological conditions. In contrast, the BIA method did not show this circadian variation but showed independent results over the measurement period. This difference in performance implies that the DC and AC responses of the human body contain different electrophysiological information.

Microbiological Results From Middle Ear Effusion in Pediatric Patients Receiving Ventilation Tube Insertion: Multicenter Registry Study on the Effectiveness of Ventilation Tube Insertion in Pediatric Patients With Chronic Otitis Media With Effusion: Part I.

OBJECTIVES: The aim of this multicenter registry study was to investigate the effectiveness of ventilation tube insertion and the microbiology of otitis media with effusion (OME) in children. This part I study was conducted to evaluate the microbiological profile of children with OME who needed ventilation tube insertion. METHODS: Patients <15 years old who were diagnosed as having OME and received ventilation tube insertion were prospectively enrolled in 16 tertiary hospitals from June 2014 to December 2016. After excluding patients with missing data, the data of 397 patients were analyzed among a total of 433 enrolled patients. The clinical symptoms, findings of the tympanic membrane, hearing level, and microbiological findings were collected. RESULTS: In 103 patients (25.9%), antibiotics were used within 3 weeks before surgery. Ventilation tube insertion was performed in a total of 710 ears (626 in both ears in 313 patients, 55 in the left ear only, and 29 in the right ear only). Culture of middle ear effusion was done in at least one ear in 221 patients (55.7%), and in a total of 346 ears. Only 46 ears (13.3%) showed positive results in middle ear effusion culture. Haemophilus influenzae (17.3%, followed by coagulase-negative Staphylococcus and Staphylococcus auricularis) was the most common bacteria detected. CONCLUSION: H. influenzae was the most commonly found bacteria in middle ear effusion. Relatively low rates of culture positivity were noted in middle ear effusion of patients with OME in Korea.

A quantitative analysis of gait patterns in vestibular neuritis patients using gyroscope sensor and a continuous walking protocol.

BACKGROUND: Locomotion involves an integration of vision, proprioception, and vestibular information. The parieto-insular vestibular cortex is known to affect the supra-spinal rhythm generators, and the vestibular system regulates anti-gravity muscle tone of the lower leg in the same side to maintain an upright posture through the extra-pyramidal track. To demonstrate the relationship between locomotion and vestibular function, we evaluated the differences in gait patterns between vestibular neuritis (VN) patients and normal subjects using a gyroscope sensor and long-way walking protocol. METHODS: Gyroscope sensors were attached to both shanks of healthy controls (n=10) and age-matched VN patients (n = 10). We then asked the participants to walk 88.8 m along a corridor. Through the summation of gait cycle data, we measured gait frequency (Hz), normalized angular velocity (NAV) of each axis for legs, maximum and minimum NAV, up-slope and down-slope of NAV in swing phase, stride-swing-stance time (s), and stance to stride ratio (%). RESULTS: The most dominant walking frequency in the VN group was not different compared to normal control. The NAVs of z-axis (pitch motion) were significantly larger than the others (x-, y-axis) and the values in VN patients tended to decrease in both legs and the difference of NAV between both group was significant in the ipsi-lesion side in the VN group only (p=0.03). Additionally, the gait velocity of these individuals was decreased relatively to controls (1.11 ± 0.120 and 0.84 ± 0.061 m/s in control and VN group respectively, p<0.01), which seems to be related to the significantly increased stance and stride time of the ipsi-lesion side. Moreover, in the VN group, the maximum NAV of the lesion side was less, and the minimum one was higher than control group. Furthermore, the down-slope and up-slope of NAV decreased on the impaired side. CONCLUSION: The walking pattern of VN patients was highly phase-dependent, and NAV of pitch motion was significantly decreased in the ipsi-lesion side. The change of gait rhythm, stance and stride time, and maximum/minimum NAV of the ipsi-lesion side were characteristics of individuals with VN.

Ambulatory balance monitoring using a wireless attachable three-axis accelerometer.

BACKGROUND AND OBJECTIVES: The ability of conventional diagnostic equipment to monitor feelings of dizziness experienced during daily activities is limited. Our goal is to develop an ambulatory multipurpose device for monitoring balance to prevent falling in daily life. MATERIALS AND METHODS: A three-axis accelerometers and gyroscope sensors were attached to the head, pelvis, and legs of vestibular neuritis (VN) patients or age-, height-, and body weight-matched healthy volunteers. The sum of the deviations for the scalar value of acceleration [signal vector magnitude, SVM (g)] and angular velocity (°/s) was measured using the modified Romberg test. RESULTS: The repeated measure ANOVA model with acceleration showed a greater group difference (p < 0.001) than that with angular velocity (p < 0.01). There was no significant interaction effect within-subjects factor between replication and groups (p < 0.178). SVM within the VN group significantly increased for all sensor locations compared to the control group (p < 0.01). Strong correlations between measurements taken at head and pelvis as sensor location were observed for both groups (VN/control, r=0.68/r=072). CONCLUS ION: The SVM appears to accurately assess balance while standing, even repetitive measurement or any location in body.

A new rat model for investigation of subglottic stenosis.

CONCLUSION: This study attempted to develop a new rat model of subglottic stenosis (SGS), resulting from subglottic mucosal injury administered by electrocauterization. Despite failure of the posterior SGS model, the anterior SGS model was considered feasible. OBJECTIVE: To investigate the feasibility of using rats as an animal model for SGS. METHODS: Thirty-seven female Sprague-Dawley rats were assigned to the control group or to the anterior or posterior subglottic injury group. Electrical cauterization was performed on the anterior or posterior 180° of the subglottic mucosa. Animals were euthanized at 4 weeks after injury. Histologic features of the subglottis were evaluated as regards changes in the subglottic lumen, lamina propria, cartilage, and epithelium after hematoxylin and eosin and Masson trichrome staining. RESULTS: Survival in the anterior injury group was 80% (13/15) until 4 weeks, and results of histologic evaluation showed an increase in thickness of lamina propria with fibrosis and cartilage damage, resulting in luminal narrowing. A high rate of mortality was observed in the posterior injury group.

Rotational responses of vestibular-nerve afferents innervating the semicircular canals in the C57BL/6 mouse.

Extracellular recordings were made from vestibular-nerve afferents innervating the semicircular canals in anesthetized C57BL/6 mice ranging in age from 4-24 weeks. A normalized coefficient of variation was used to divide afferents into regular (CV*<0.1) and irregular (CV*>0.1) groups. There were three overall conclusions from this study. First, mouse afferents resemble those of other mammals in properties such as resting discharge rate and dependence of response dynamics on discharge regularity. Second, there are differences in mouse afferents relative to other mammals that are likely related to the smaller size of the semicircular canals. The rotational sensitivity of mouse afferents is approximately threefold lower than that reported for afferents in other mammals. One consequence of the lower sensitivity is that mouse afferents have a larger linear range for encoding head velocity. The long time constant of afferent discharge, which is a measure of low-frequency response dynamics, is shorter in mouse afferents than in other species. Third, juvenile mice (age 4-7 weeks) appear to lack a class of low-sensitivity, highly irregular afferents that are present in adult animals (age 10-24 weeks). By analogy to studies in the chinchilla, these irregular afferents with low sensitivities for lower rotational frequencies correspond to calyx-only afferents. These findings suggest that, although the calyx ending on to type I hair cells is morphologically complete in mice by the age of about 1 month, the physiological response properties in these juvenile animals are not equivalent to those in adults.

Clinical characteristics of benign paroxysmal positional vertigo in Korea: a multicenter study.

Benign paroxysmal positional vertigo (BPPV) is characterized by episodic vertigo and nystagmus provoked by head motions. To study the characteristics of BPPV in a large group of patients in Korea, we retrospectively analyzed clinical features of 1,692 patients (women: 1,146, 67.7%; men: 54.6, 32.3%; mean age: 54.8+/-14.0 yr), who had been diagnosed as BPPV by trained neuro-otologists Dizziness Clinics. The diagnosis of BPPV was based on typical nystagmus elicited by positioning maneuvers. Posterior semicircular canal was involved in 60.9% of the patients, horizontal canal in 31.9%, anterior canal in 2.2%, and mixed canals in 5.0%. The horizontal canal type of BPPV (HC-BPPV) comprised 49.5% of geotropic and 50.5% of apogeotropic types. We could observe significant negative correlation between the proportion of HC-BPPV of each clinic and the mean time interval between the symptom onset and the first visit to the clinics (r=-0.841, p<0.05). Most patients were successfully treated with canalith repositioning maneuvers (86.9%). The high incidence of HC-BPPV in this study may be explained by relatively shorter time interval between the symptom onset and visit to the Dizziness Clinics in Korea, compared with previous studies in other countries.

Antimicrobial peptide LL-37 is upregulated in chronic nasal inflammatory disease.

OBJECTIVE: LL-37 is one of the antimicrobial peptides and the only member of the cathelicidin family identified so far in humans. We attempted to find a correlation between LL-37 peptide and inflammation of the nasal mucosa. MATERIAL AND METHODS: Nasal mucosa specimens were obtained from 15 chronic infective rhinitis patients and 6 normal controls. Immunohistochemical staining was used to examine the localization of LL-37 and reverse transcriptase polymerase chain reaction (RT-PCR) was used to determine the levels of LL-37, IL-1beta and IL-8 in tissue. RESULTS: LL-37 peptide was primarily localized in the surface of the epithelia, in the serous and mucous cells of the submucosal glands and in stromal inflammatory cells. The number of LL-37 immunoreactive cells in inflammatory nasal mucosa was significantly increased compared with normal nasal tissue. Using RT-PCR, LL-37 mRNA was detected in 3/6 normal turbinate samples but in all cases with inflammatory nasal tissues. IL-1beta and IL-8 transcripts exhibited a similar pattern to that of LL-37. CONCLUSIONS: We suggest that LL-37 is one of the antimicrobial peptides found in human nasal mucosa and that it participates in the innate immune system of the nasal mucosa.