Frequency dependence of human thresholds: both perceptual and vestibuloocular reflex thresholds.

Although perceptual thresholds have been widely studied, vestibuloocular reflex (VOR) thresholds have received less attention, so the relationship between VOR and perceptual thresholds remains unclear. We compared the frequency dependence of human VOR thresholds to human perceptual thresholds for yaw head rotation in both upright ("yaw rotation") and supine ("yaw tilt") positions, using the same human subjects and motion device. VOR thresholds were generally a little smaller than perceptual thresholds. We also found that horizontal VOR thresholds for both yaw rotation about an Earth-vertical axis and yaw tilt (yaw rotation about an Earth-horizontal axis) were relatively constant across four frequencies (0.2, 0.5, 1, and 2 Hz), with little difference between yaw rotation and yaw tilt VOR thresholds. For yaw tilt stimuli, perceptual thresholds were slightly lower at the lowest frequency and nearly constant at all other (higher) frequencies. However, for yaw rotation, perceptual thresholds increased significantly at the lowest frequency (0.2 Hz). We conclude 1) that VOR thresholds were relatively constant across frequency for both yaw rotation and yaw tilt, 2) that the known contributions of velocity storage to the VOR likely yielded these VOR thresholds that were similar for yaw rotation and yaw tilt for all frequencies tested, and 3) that the integration of otolith and horizontal canal signals during yaw tilt when supine contributes to stable perceptual thresholds, especially relative to the low-frequency perceptual thresholds recorded during yaw rotation.NEW & NOTEWORTHY We describe for the first time that human VOR thresholds differ from human forced-choice perceptual thresholds, with the difference especially evident at frequencies below 0.5 Hz. We also report that VOR thresholds are relatively constant across frequency for both yaw rotation and yaw tilt. These findings are consistent with the idea that high-pass filtering in cortical pathways impacts cognitive decision-making.

High fluence in laser stapedotomy aggravates transient subjective dizziness.

BACKGROUND: Laser fenestration in stapedotomy has thermal effect to the vestibule. AIMS/OBJECTIVES: To evaluate the role of energy density (fluence) in the severity of postoperative vestibular symptoms. MATERIALS AND METHODS: The retrospective chart-review study included 84 patients with otosclerosis that underwent primary laser stapedotomy. Surgical outcomes, including nystagmus, and subjective vestibular symptoms during one-month follow-up, were compared between potassium titanyl phosphate (KTP) and CO2 laser. According to this study and literature, we assessed the relationship between laser parameters and the incidence of persistent vestibular symptoms lasting more than one week after surgery. RESULTS: The KTP and CO2 laser group included 48 and 36 patients, respectively. Fluence was different between the KTP (637 J/cm2) and CO2 (141 J/cm2) laser (p < .001). The KTP group showed gradual decrease in dizziness during one-month observation period, while the CO2 group exhibited a steep recovery curve in the first postoperative week (9 and 4 d of duration, respectively). The incidence of persistent vestibular symptoms was correlated with both fluence (r = 0.80, p = .01) and spot size (r = -0.74, p = .01). CONCLUSIONS AND SIGNIFICANCE: Appropriate setting of parameters with lower fluence is desirable for the efficiency and safety of laser stapedotomy.Abbreviations: ABG: air-bone gap; SD: standard deviation.

Sustained deviation of torsional eye position associated with transient semicircular canal stimulation.

BACKGROUND: Vestibular stimulation causes postural unsteadiness accompanied by a sensation of tilt. AIMS/OBJECTIVES: The mechanism of the sensation of tilt needs to be assessed by accurate calculation of the rotational axis of torsional eye position under various vestibular stimulations. MATERIAL AND METHODS: Twenty-two healthy subjects participated in the study. Thirteen subjects underwent bilateral vestibular stimulation by on-axis yaw rotation under various head positions, and eighteen subjects underwent unilateral vestibular stimulation by caloric irrigation under various head positions. Listing's Plane was plotted for the eye movement data obtained by three-dimensional video-oculography. RESULTS: The offset of Listing's Plane showed sustained deviation of torsional eye position that was more prominent in head positions that stimulated lateral semicircular canals more than vertical semicircular canals. There was a less prominent and directionally reversed offset in head positions that stimulated vertical canals more than lateral semicircular canals. CONCLUSION AND SIGNIFICANCE: The sustained torsional eye position was validated by accurate assessment using Listing's Plane. The mechanism behind the deviation may be due to a combination of multiple anatomical components within the vestibular apparatus, with potentially stronger influence from lateral semicircular canals.

Cholesteatoma has an altered microbiota with a higher abundance of Staphylococcus species.

Objective: To compare the microbiota between cholesteatoma and chronic suppurative otitis media (COM) and to identify potential pathogens that explain the relevant phenotypes of cholesteatoma. Study Design: Prospective cohort study. Methods: Surgical specimens collected from 20 cholesteatomas and nine COMs were treated to dissolve biofilms and subjected to 16S ribosomal RNA (rRNA) gene sequencing and amplicon sequence variant-level analysis for microbiota profiling and quantitative comparison. Correlations between the relative abundance of potential pathogens and the volume of the primary resected cholesteatomas were examined. Results: Differences in bacterial composition (beta diversity) were observed between cholesteatomas and COM (p = .002), with a higher abundance of Staphylococcus in cholesteatomas than in COM (p = .005). Common genera in the external auditory canal (EAC) flora, such as Staphylococcus, Corynebacterium, and Cutibacterium, were predominant in both cholesteatoma and COM; Staphylococcus aureus and Pseudomonas aeruginosa were increased in both diseases compared with the EAC flora. Furthermore, coagulase-negative staphylococci (CoNS) were more abundant in cholesteatomas than in COM (p = 0.002). Linear discriminant analysis coupled with effect size measurements (LEfSe) identified four CoNS as potential biomarkers for cholesteatoma. The relative abundance of S. aureus, a potential pathogen, was positively correlated with cholesteatoma volume (r = .60, p = .02). Conclusion: The microbiota of cholesteatoma and COM originated from EAC flora, but the bacterial composition was largely altered. Our results suggested that S. aureus infection is involved in cholesteatoma progression. Level of Evidence: 3b.

Denosumab-induced osteonecrosis of external auditory canal.

Denosumab is the world's first human monoclonal antibody for the treatment of osteoporosis and shares an active pathway with bisphosphonates, strongly suppressing osteoclast activities. This is the first case report describing a possible relationship between the development of osteonecrosis of external auditory canal and denosumab administration. We herein report an 81-year-old woman diagnosed with left osteonecrosis of external auditory canal who had a history of denosumab administration. She underwent left radical mastoidectomy due to being refractory to conservative treatment. No major complications or recurrence were observed in the left ear after surgery, but bone erosion in the right ear has continued to progress slowly despite the cessation of denosumab administration. Otolaryngologists should be aware of the association between osteonecrosis of external auditory canal and denosumab administration and consider performing long-term observation even after cessation.

Clinical application of 3D-VOG analysis for quantitative evaluation of Otolith-Ocular reflex in the roll and pitch planes.

BACKGROUND: Management of vestibular falls requires precise evaluation of otolithic function and gravity recognition. Tilt of the head in the roll plane causes ocular counter rolling (OCR) with a gain of 5-10%, which can be a quantitative parameter related to the otolith-ocular reflex (OOR) in that plane. However, the OOR in the pitch plane is indiscernible because of our ability to voluntarily gaze and pursue. 3 D eye movements and its Listing's plane description can provide novel parameters with which to evaluate OOR, even in the pitch plane. OBJECTIVES: To evaluate the utility of 3 D eye movement analysis in video oculography (VOG) as a quantitative parameter reflecting otolithic function during head movements associated with daily life. MATERIALS AND METHODS: In healthy subjects, we analyzed the changes in 3 D eye movements and the Listing's plane that occur with static gravitational modification. RESULTS: OOR during head tilt in the roll plane revealed that OCR amplitude had a saturating/peaked conformation and was not fitted by a sine curve. OOR in the pitch plane revealed anteroposterior leaning of the Listing's plane. CONCLUSIONS: These novel tools for minimally invasive evaluation of OOR in a clinical setting could potentially enable us to quantitatively evaluate peripheral static disequilibrium.

Potential Confounding Factors May Influence the Association Between Configurations of the Vertebrobasilar System and the Incidence of Idiopathic Sudden Sensorineural Hearing Loss and Canal Paresis.

OBJECTIVE: To investigate the impact of configurations of the vertebrobasilar system on the incidence of idiopathic sudden sensorineural hearing loss (ISSNHL) and canal paresis (CP). STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral center. PATIENTS: Two hundred and forty-eight consecutive patients diagnosed with ISSNHL and 152 patients with unilateral CP of an uncertain cause who were managed between January 2011 and December 2017. The contralateral side of 144 patients with Bell's palsy or cerebellopontine angle tumor served as a control. INTERVENTIONS: All patients underwent magnetic resonance cisternography. CP was diagnosed based on caloric testing. MAIN OUTCOME MEASURES: 1) Branching patterns of the anterior/posterior inferior cerebellar artery (AICA/PICA) in the cerebellopontine angle area. 2) The direction of the basilar artery (BA) curvature. 3) Vertebral artery (VA) dominance. RESULTS: The incidence of vascular loops of the AICA/PICA entering the internal acoustic canal was significantly higher on both the affected and unaffected sides in patients with ISSNHL and CP in comparison to controls (p < 0.05). The curved BA was observed more frequently in the ISSNHL and CP groups than in the control group (p < 0.05), whereas the direction of the BA curvature was not associated with the laterality of ISSNHL or CP. The incidence of asymmetric VA in CP patients was significantly higher than that in controls (p = 0.0304), while no significant difference was observed between ISSNHL patients and controls. Remarkably, while the incidence rate of irregular vascular configurations was high in both the ISSNHL and CP groups, there was no marked difference between the affected and unaffected ears of the ISSNHL and CP groups. CONCLUSIONS: Our results indicate that the vascular configurations of the vertebrobasilar system do not directly cause ISSNHL and CP. Instead, they suggest the presence of confounding factors that influence the vascular configurations and the development of ISSNHL and CP.

Frequency analyses of posturography using logarithmic translation.

Background: Power-spectral analysis of the centre of pressure (CoP) frequencies of posturography provides exponentially approximated distributions, whereas logarithmic translation enables linear approximation.Objectives: Frequency analyses were adopted for posturography of healthy subjects and patients with spinocerebellar degeneration (SCD) using logarithmic translation to determine its clinical usefulness for managing the elderly and patients with disequilibrium.Material and methods: We included 172 healthy subjects and 47 SCD patients. Posturography was performed with the eyes fixated and closed, with and without foam rubber. The power-spectral data of the CoP were obtained with the maximum entropy method. Power-spectral data were logarithmically translated for quantitative evaluation.Results: For teenagers, high-frequency fluctuations were dominant and attributable to proprioceptive compensation due to immature postural control. In elderly populations, the increased frequency in the lateral direction was characterised by three peaks indicating postural disturbances attributed to three sensory inputs. The disappearance of one peak in the anteroposterior fluctuation indicates a decrease in vestibular contribution. The foam rubber and the closed-eye condition enhanced fluctuations in two peaks. There were differences in power-spectral distributions of two peaks between the healthy subjects and SCD patients.Conclusions: Logarithmic power-spectral data distribution could provide an age- and disease-specific novel and visually-comprehensible parameter.

The evaluation of gravitational recognition in patients with spinocerebellar degeneration using Listing's plane.

Background: The thickness of Listing's plane accurately reflects gravitational recognition, constructed through the integration of visual, vestibular, and proprioceptive sensory input in the neural integrator of the central nervous system. Spinocerebellar degeneration (SCD) is a progressive degenerative disease mainly involving the cerebellum and brainstem that leads to destabilize the gravitational recognition, and may thicken thickening of Listing's plane. Objective: The aim of this study is to evaluate the gravitational recognition in response to positional change in patients with SCD, using the thickness of Listing's plane as a parameter. Materials and methods: In this prospective study, we evaluated the thickness of Listing's plane in 21 consecutive patients with SCD and 32 healthy subjects in the seated and supine positions, and investigated the association with other neuro-otological examinations (electronystagmography including caloric test and posturography). Results: We detected significant thickening of Listing's plane in SCD patients only when they were in the seated position. The thickness of Listing's plane correlated with neither the caloric response nor Romberg's ratio or the total center of the pressure path length. Conclusions and significance: The thickness of Listing's plane could be a useful parameter for assessing a gravity-oriented internal model in SCD patients.

Vestibular Dysfunction in Patients With Superficial Siderosis of the Central Nervous System.

OBJECTIVE: To describe the vestibular function in patients with superficial siderosis of the central nervous system (SSCN). STUDY DESIGN: Retrospective analysis. SETTING: Tertiary referral center. PATIENTS: Ten consecutive patients with SSCN. This study is the largest case series of SSCN in which detailed neuro-otological findings, including electronystagmography recording, video head impulse test (vHIT), and posturography, were described. INTERVENTIONS: Audiological and neuro-otological examinations, including pure-tone audiometry, distortion product otoacoustic emissions, speech audiometry, auditory brainstem responses, electronystagmography recording, vHIT, and posturography. MAIN OUTCOME MEASURES: Pure-tone average, DP level, maximum speech discrimination score, interpeak latency between auditory brainstem responses waves I and V, eye tracking test, examination of optokinetic nystagmus, caloric response, visual suppression, vestibulo-ocular reflex gains, total center of pressure path length, and Romberg's ratio. RESULTS: Audiological examinations suggested that the sensorineural hearing loss was of a cochlear etiology in 3 ears, a retrocochlear etiology in 11 ears, and a combined cochlear and retrocochlear etiology in 6 ears. Neuro-otological examinations revealed that eight out of nine patients had cerebellar disorders, while all patients also had peripheral vestibular dysfunction. CONCLUSION: In addition to cerebellar disorders, SSCN patients suffer from severe peripheral vestibular dysfunction, which can exacerbate the patient's imbalance. When otolaryngologists encounter patients with distinctly progressive sensorineural hearing loss and imbalance, they should include SSCN in the differential diagnosis and perform neuro-otological examinations, including an electronystagmography recording and vHIT and brain magnetic resonance imaging.

Determination of the time course of caloric nystagmus in patients with spinocerebellar degeneration using caloric step stimulus procedure.

CONCLUSIONS: The step stimulus procedure can provide information on the time course of the vestibulo-ocular reflex. Spinocerebellar degeneration and aging seem to shorten the time constant of the onset of the vestibulo-ocular reflex, causing a rapid rise up. Failure of the central processing of velocity storage might contribute to this rapid rise up. OBJECTIVES: The aim of this study is to evaluate the time course characteristics of the vestibulo-ocular reflex in patients with spinocerebellar degeneration. METHODS: Ten patients (20 ears) and 22 healthy subjects (30 ears) underwent caloric test using the step stimulus procedure. We evaluated the time course of caloric VOR and calculated the parameters of the time constant of an activation and adaptation response. We compared between the control and SCD groups to elucidate the time course characteristics of caloric VOR in patients with SCD. RESULTS: Spinocerebellar degeneration seems to shorten the time constant of the activation response by caloric irrigation with 20 °C, 7l/min air. However, aging also possibly contributes to this shortening. No change was observed in the time constant of the adaptation response.

Nystagmus at the Onset of Vertiginous Attack in Ménière's Disease.

OBJECTIVE: To clarify the direction and characteristics of nystagmus at the onset of a vertiginous attack in Ménière's disease. PATIENTS: Two patients with Ménière's disease, whose nystagmus at the onset of a vertiginous attack was recorded using electronystagmography. INTERVENTIONS: Diagnostic. MAIN OUTCOME MEASURES: Electronystagmographic recordings of nystagmus. RESULTS: In both patients, nystagmus was directed toward the affected side over the entire course of the vertiginous attack. One patient experienced a severe sensation of vertigo and exhibited strong nystagmus from the onset of the attack. The other patient reported a mild sensation of vertigo, which was accompanied by intermittent nystagmus. CONCLUSIONS: Vertiginous attacks in Ménière's disease are accompanied by irritative nystagmus. The intensity and characteristics (e.g., continuous or intermittent expression) of the nystagmus may be associated with pathophysiological severity.

Clinical Characteristics of Pediatric Deep Neck Abscesses.

Pediatric deep neck abscesses are a relatively rare and can lead to critical or life-threatening situations. However, the clinical characteristics of pediatric deep neck abscesses are not fully understood in Japan. We conducted a retrospective study of the clinical characteristics of children presenting with pediatric deep neck abscesses at our hospital. All pediatric patients were diagnosed with deep neck abscesses on the basis of the clinical findings and computed tomography (CT) scanning of the neck between April 2009 and March 2014. The incidence, initial examining department, sex, age, presenting signs and symptoms, physical findings, duration between onset and admission, timing of CT scanning, abscess location, causative organism, and method of treatment were determined from the medical records. 　We identified a total of 20 pediatric patients with deep neck abscesses, with a mean incidence of 4.0±1.9 cases per year. Pediatric deep neck abscesses were more common during winter and spring. Most patients initially presented to the pediatric department before consulting an otolaryngologist. Fourteen (70%) patients were male and six (30%) were female, with no obvious peak age of onset. The mean duration between onset and admission was 7.2±3.9 days. The mean timing of CT scanning was 8.1±3.6 days after onset. The most commonly involved area was the retropharyngeal space in nine (45%) and the retro-cervical space in eight (40%) patients. The most frequent causative organism was Staphylococcus aureus (20%), with no cases of antibiotic-resistant bacteria infection observed. Majority of the children were initially managed with conservative treatment. Five patients who failed to improve within 48 h of treatment subsequently underwent surgical drainage. No significant complications such as descending mediastinitis and septic shock were observed in any of the patients.

Preoperatively diagnosed case with co-existence of papillary thyroid carcinoma and cervical tuberculous lymphadenitis.

INTRODUCTION: Papillary thyroid cancer (PTC) is the most frequent histological subtype of thyroid cancer. The lymph node metastasis is found in a high proportion of patients with PTC at the time of surgery. In contrast, tuberculous lymphadenitis remains a common cause of cervical lymphadenopathy in Asian countries. PRESENTATION OF CASE: We present a 60-year-old woman with coexistence of papillary thyroid carcinoma (PTC) and cervical tuberculous lymphadenitis and to show the usefulness of fine-needle aspiration biopsy (FNAB) and quantiferon testing to distinguish a lymph node metastasis of PTC from tuberculous lymphadenitis. DISCUSSION: FNAB and quantiferon testing are useful tools to check if enlargement of cervical lymph node is due to tuberculous infection, and a surgical plan should be carefully determined to avoid unnecessary surgical complications and the spread of tuberculous infection. CONCLUSION: The coexistence of cervical tuberculosis should be considered in the etiology of an enlarged lymph node for patients with PTC.

[Rate and clinical characteristics of mumps reinfection].

Mumps infection is anecdotally believed to occur only once over a lifetime. However, in recent years, it has gradually come to be recognized among pediatricians that mumps reinfection is not a rare condition, and some criteria for the mumps reinfection have been proposed. One of the widely accepted criteria is levels higher than 25.8 IU/dl of serum IgG antibodies against the mumps virus and lower than 2.0 IU/dl of serum IgM antibodies. From July 2010 to June 2011, 45 patients with acute swelling of the major salivary gland(s) were enrolled into our survey of mumps reinfection in Tsuchiura Kyodo General hospital. Serum IgG and IgM antibodies against the mumps virus were measured at the initial visit. Ten cases were diagnosed as having primary infection with the mumps virus, while the other 10 cases were diagnosed as having reinfection with the mumps virus according to the criteria. The present study suggests that mumps reinfection is a common condition in patients with acute swelling of the major salivary glands in adulthood.