Aki Inoue

Effect of vestibular dysfunction on the development of gross motor function in children with profound hearing loss.

Objective: To evaluate the function of the superior and inferior vestibular nerve systems in children with profound sensorineural hearing loss, and to assess the influence of dysfunction of each vestibular nerve system on the development of gross motor function. Study Design: Retrospective study. Setting: A tertiary referral center. Methods: Eighty-nine children (age range: 20–97 months) with profound sensorineural hearing loss who were due to undergo cochlear implant surgery were recruited. Function of the superior vestibular nerve system was evaluated by the damped rotation test and the caloric test, whereas functions of the inferior vestibular nerve systems were evaluated by the vestibular evoked myogenic potential (VEMP) test. Gross motor development was assessed using the age of acquisition of head control and independent walking. Results: Among the children able to complete the vestibular function tests, abnormalities were found in 20% (16 of 84 children) in the damped rotation test, 41% (31 of 75 children) in the caloric test and 42% (26 of 62 children) in the VEMP test. Children who showed abnormal responses in the vestibular function tests showed significantly delayed acquisition of head control (p < 0.05) and independent walking (p < 0.05) in comparison with children with normal responses. The children who showed abnormal responses in all 3 vestibular tests showed the greatest delay in acquisition of gross motor function in comparison with the other groups. Conclusions: Children with profound hearing loss tend to have dysfunction in the superior as well as the inferior vestibular nerve systems. Both the superior and inferior vestibular nerve systems are important for the development of gross motor function in children.

Clinical characteristics of inferior vestibular neuritis

Abstract Conclusions: Inferior vestibular neuritis (IVN) is a relatively minor subtype of vestibular neuritis (VN) and its clinical characteristics are unique. Objectives: To clarify clinical characteristics of IVN in comparison with conventional VN. Methods: This was a retrospective case series review. Caloric responses and cervical vestibular evoked myogenic potential (cVEMP) responses were measured in 71 patients with VN. The patients were classified into three groups: (1) IVN group, who showed only asymmetrical cVEMP responses; (2) superior VN (SVN) group, who showed only asymmetrical caloric responses; (3) total VN (TVN) group, who showed asymmetrical responses in both tests. The clinical records of time course of subjective symptoms (duration of attack, duration of hospitalization, and time to remission) were reviewed and other profiles (age, sex, affected side, acute symptoms, and sequelae) were evaluated. Results: Of the 71 patients with VN, 13 (18%) were classified as having IVN. The mean age and time to remission of patients with IVN (44.2 ± 4.8 years, 0.9 ± 0.5 months) were significantly lower and shorter, respectively, than those of patients with TVN (57.3 ± 2.5 years, 4.9 ± 4.7 months). There were no significant differences in other symptoms and profiles among the three groups. No patients with IVN showed benign paroxysmal positional vertigo as a sequela.

Ocular vestibular evoked myogenic potentials in response to air-conducted sound and bone-conducted vibration in vestibular schwannoma.

Objective To clarify the origin and pathways of ocular vestibular evoked myogenic potentials (oVEMPs) to air-conducted sound (ACS), we compared the results of oVEMPs with ACS, with oVEMPs with bone-conducted vibration (BCV), cervical VEMPs (cVEMPs) with ACS, and the caloric test in patients with unilateral vestibular schwannoma (VS). Study Design Retrospective review. Setting Tertiary referral center. Patients Forty-five patients with untreated unilateral VS. Main Outcome Measure Each patient underwent vestibular tests, including oVEMPs to ACS, oVEMPs to BCV, cVEMPs to ACS, and caloric tests. The correlations among these tests were evaluated. Results Of the 45 patients recruited, 28 patients (63%) showed reduced or absent oVEMPs to ACS solely on the affected side. There were no significant differences in abnormal response ratios among oVEMPs to ACS, oVEMPs to BCV, cVEMPs to ACS, or the caloric test. The results of oVEMPs to ACS had a significant correlation with those of oVEMPs to BCV and the caloric test (p < 0.05) but not with those of cVEMPs to ACS (p > 0.05). Conclusion These findings support the hypothesis that oVEMP in response to ACS are predominantly mediated by the superior vestibular nerve and probably reflect the function of the utricle.

Diagnostic usefulness of multifrequency tympanometry for Ménière's disease.

Multifrequency tympanometry (MFT) is the measurement of the impedance of the middle ear transmission system at a wide range of frequencies from 200 Hz to 2 kHz. A potential use of MFT as a new diagnostic tool for detecting endolymphatic hydrops has recently been reported. However, its clinical usefulness for diagnosing Ménière’s disease (MD) remains unclear. To evaluate the clinical usefulness of MFT as a new qualitative and diagnostic test for MD, we performed MFT in 70 patients with unilateral or bilateral MD and in 29 normal control subjects. The width of double peaks in the admittance tympanograms (Y width) at 2 kHz and the resonance frequency (RF) were analyzed, and receiver operating characteristic (ROC) curves were constructed. The Y width in MD-affected ears was significantly greater than that in control ears (p < 0.001). The RF in MD-affected ears was significantly lower than that in control ears (p < 0.01). Neither the Y width nor RF had a significant relationship with hearing levels or the results of caloric and vestibular myogenic potential testings. The area under the ROC curve was 0.71 for the Y width and 0.66 for the RF. At the optimal cutoff points, the sensitivity and specificity of the Y width were 47.3 and 86.8%, respectively, and those of the RF were 41.3 and 84.2%, respectively. These results indicated that MFT is significantly associated with the presence of MD, but its diagnostic accuracy is only modest. MFT is a simple, noninvasive test, which should be considered as a complementary test in the diagnosis of MD.

Developmental changes in the expression of Κv1 potassium channels in rat vestibular ganglion cells

The primary afferent neurons of the vestibular ganglion convey sensory information from hair cells in the semicircular canals and otolith organs to the vestibular nuclei, the adjacent brainstem and the cerebellum. The intrinsic firing properties of vestibular ganglion cells (VGCs) are heterogeneous and have been classified into phasic, intermediate and tonic firing types on the basis of their response to injected depolarizing currents. A previous study from our group showed that the proportion of phasic discharging VGCs decreased during the first postnatal weeks. Moreover, α-dendrotoxin (α-DTX), a Kv1 potassium channels antagonist, turned neuron phasic firing to tonic, thus suggesting that these channels play an important role in the developmental changes of VGCs firing patterns. Here, by using immunohistochemistry, Western blotting and quantitative real-time reverse transcriptase-polymerase chain reaction (RT-PCR), we explored the change in the expression of α-DTX-sensitive K(+) channels, Kv1.1, Kv1.2 and Kv1.6 in rat VGCs during early postnatal periods. We showed that expression of Kv1.6 protein is down-regulated together with expression of Kv1.6 mRNA after postnatal day 7 in rat VGCs whereas expression of Kv1.1 and Kv1.2 proteins did not change during the same developmental period. Our results suggest that down-regulation of the Kv1.6 protein and mRNA may be associated with maturation of excitable properties of primary vestibular neurons.

Ocular vestibular evoked myogenic potential elicited from binaural air-conducted stimulations: clinical feasibility in patients with peripheral vestibular dysfunction.

Abstract Conclusion: Ocular vestibular evoked myogenic potentials (oVEMPs) to binaural air-conducted stimulation (ACS) may provide a convenient way of assessing the crossed vestibulo-ocular reflex in patients with vestibular dysfunction as well as in healthy subjects. Objective: To investigate the clinical feasibility of using oVEMPs in response to binaural ACS to assess normal subjects and patients with vestibular dysfunction. Methods: The study investigated 24 normal subjects (14 men and 10 women, aged from 23 to 60 years) and 14 patients with unilateral peripheral vestibular dysfunction. Each subject underwent oVEMP testing in response to monaural ACS and binaural ACS (500 Hz tone burst, 135 dBSPL). Results: In normal subjects, bilateral oVEMPs were elicited in 75% of subjects in response to monaural ACS and in 91% in response to binaural ACS. Asymmetry ratios (ARs) of the responses to binaural ACS were significantly smaller than those of the responses to monaural ACS (p < 0.01). In patients with unilateral vestibular dysfunction, there were no significant differences in the amplitude, latency, or AR of the responses between monaural and binaural ACS. Approximately 30% of patients showed reduced ARs to binaural ACS relative to monaural ACS, primarily due to contamination by uncrossed responses elicited in healthy ears.

Differential diagnosis of proptosis: Report of 2 cases

We rarely encounter patients with proptosis, however, it is known that inflammation and extension of paranasal sinus tumors may cause this condition. We should consider the diseases that may cause proptosis to facilitate the diagnosis. Recently, we treated proptosis in 2 cases, one with inflammatory myofibroblastic tumor (IMT) and the other with malignant lymphoma. As these 2 diseases show various clinical features and these features frequently overlap, it is difficult to differentiate between IMT and malignant lymphoma without pathological examinations. In this study, we review the relevant literature reports and discuss the difficulties in establishing a clinicopathological diagnosis and present a slight distinction in magnetic resonance imaging.

Vocal cord abductor paralysis in multiple system atrophy: a case report

Multiple system atrophy (MSA) is a progressive neurodegenerative disease that is characterized by varying degrees of parkinsonism and cerebellar, corticospinal, and autonomic dysfunction. Vocal cord abductor paralysis (VCAP) is considered a sign of a poor prognosis in MSA, because it is a life-threatening complication that may cause nocturnal sudden death. This case report presents a patient who was treated for Parkinsons disease, and complained of dizziness and sleep apnea. We examined VCAP using fiberoptic laryngoscopy as the possible cause of sleep apnea. VCAP usually occurs in the advanced stages of MSA and is accompanied by a worsening of other symptoms. Optokinetic nystagmus was severely impaired and the caloric test response was bilaterally absent. Objective findings such as VCAP and abnormal neuro-otological results led to the diagnosis of MSA.

A clinical review of 38 cases of cervical tuberculous lymphadenitis in Japan - The role of neck dissection.

OBJECTIVES After tuberculous pleurisy, lymphadenitis arising from cervical lesion is the second most common form of extrapulmonary tuberculosis. It is generally treated with antituberculosis agents, but some patients resist chemotherapy. In such cases, surgical resection is often considered as an alternative treatment. This study aims to evaluate the therapeutic outcome of cervical tuberculous lymphadenitis and the future course of treatment of this disease. METHODS We retrospectively reviewed the clinical charts of patients diagnosed at the Tokyo Metropolitan Tama Medical Center between 2009 and 2015 and identified 38 cases of cervical tuberculous lymphadenitis. Precisely 798 patients were registered for primary tuberculosis at our institution during the same period. RESULTS Patient ages ranged from 21 to 85 years (average: 58.9 years), and the male-to-female ratio was 1:1.2. The range of tuberculosis progression was as follows: 30 (78.9%) in only the cervical lymph node, 3 in the other (axillary, mediastinal, and abdominal) lymph nodes, 1 in the lung and vertebrae lumbales, 2 in the lung, and 1 in the pleural membrane. All 38 patients were initially treated with antituberculous drugs at the Department of Pulmonary Medicine based on guidelines for tuberculosis cases in Japan. In seven cases, the antituberculous drugs were replaced due to side effects. Four cases involved a single drug-resistant strain, and one case involved a double drug-resistant strain. Thirty-three (86.8%) cases were cured by chemotherapy alone. The three patients resistant to chemotherapy were successfully treated through neck dissection. Thirty-six cases (94.7%) were cured by chemotherapy or chemotherapy and surgery. CONCLUSION Local therapy could prove effective in cervical tuberculous lymphadenitis patients who exhibit an inadequate response to drugs. The role of neck dissection in cervical tuberculous lymphadenitis remains an important consideration.

Vestibular Evoked Myogenic Potentials in Vestibular Migraine: Do They Help Differentiating From Menière's Disease?

Objective: To investigate whether both cervical and ocular vestibular myogenic potentials (cVEMPs and oVEMPs) to air-conducted sound (ACS) and bone-conducted vibration (BCV) can help to differentiate vestibular migraine (VM) and Menière’s disease (MD). Study Design: Retrospective study. Settings: A tertiary referral center. Subjects and Methods: Twenty-eight patients with VM, 28 patients with definite unilateral MD, and 28 age-matched controls were included. Cervical VEMPs to 500 Hz ACS (cVEMPs-air) and 500 Hz BCV (cVEMPs-bone), oVEMPs to 500 Hz ACS (oVEMPs-air) and 500 Hz BCV (oVEMPs-bone), and caloric tests were performed. Results of these vestibular function tests were compared between the groups. Results: The prevalence of abnormality was significantly higher in VM than in controls only for the caloric test (P < .05). Asymmetry ratios (ARs) for cVEMPs-air and oVEMPs-air were significantly larger in VM than in controls (P < .05). Between VM and MD, the prevalence of abnormality was significantly different only for oVEMPs-air. The ARs for oVEMPs-air and caloric test asymmetries were significantly smaller in VM than in MD (P < .05). Conclusions: Among the vestibular function tests, oVEMPs-air may be most helpful for the differentiation of VM from MD as a group.