Vestibular Nerve Research Articles

Clinical Features and Neurotologic Findings in Patients With Acute Unilateral Peripheral Vestibulopathy Associated With Antiganglioside Antibody.

Anecdotal studies have reported the presence of antiganglioside antibodies in acute unilateral peripheral vestibulopathy (AUPV). This study aimed to determine the prevalence, clinical characteristics, and neurotologic findings of AUPV associated with antiganglioside antibodies. Serum antigangliosides were measured in consecutive patients with AUPV according to the Bárány Society criteria during the acute and recovery phases in a referral-based university hospital in South Korea from September 2019 to January 2023. Clinical characteristics and neurotologic findings were compared between those with and without antiganglioside antibodies. The results of video-oculography, video head impulse and bithermal caloric tests, and other neurotologic evaluations including ocular and cervical vestibular-evoked myogenic potentials and subjective visual vertical were compared between the 2. MRIs dedicated to the inner ear were also conducted when considered necessary. One hundred five patients (mean age ± SD = 60 ± 13 years, 57 male) were included for analyses. During the acute phase, 12 patients (12/105, 11%) were tested positive for serum antiganglioside antibodies, including anti-GQ1b immunoglobulin (Ig) G (n = 5) or IgM (n = 4), anti-GM1 IgM (n = 3), and anti-GD1a IgG (n = 1, including 1 patient with a positive anti-GQ1b antibody). Patients with antiganglioside antibodies showed lesser intensity of spontaneous nystagmus (median [interquartile range] = 1.8 [1.2-2.1] vs 3.4 [1.5-9.5], p = 0.003) and a lesser degree of canal paresis (30 [17-47] vs 58 [34-79], p = 0.028) and gain asymmetry of the vestibulo-ocular reflex for the horizontal semicircular canal during head impulse tests (0.07 [-0.04 to 0.61] vs 0.36 [0.18-0.47], p = 0.032) than those without antibodies. Negative conversion of antibodies and vestibular recovery were observed in most patients (6/8, 75%). Among 30 patients with AUPV with 4-hour delayed 3D fluid-attenuated inversion recovery dedicated to the inner ear, gadolinium enhancement was observed in 18 (18/30, 60%), either in the vestibule (n = 9), semicircular canal (n = 6), or vestibular nerve (n = 5). The positivity rates based on specific antibodies could not be determined due to limited sample sizes. The association between antiganglioside antibodies and AUPV suggests an immune-mediated mechanism in acute vestibular failure and extends the clinical spectrum of antiganglioside antibody syndrome.

Prosthetic Stimulation of the Vestibular Nerve Can Evoke Robust Eye and Head Movements Despite Prior Labyrinthectomy.

Prosthetic electrical stimulation can evoke compensatory eye and head movement despite vestibular implant electrode insertion occurring years after prior labyrinthectomy. Vestibular implants sense head rotation and directly stimulate the vestibular nerve, bypassing damaged end organs. Animal research and current clinical trials have demonstrated the efficacy of this approach. However, candidacy criteria for vestibular implants currently require presence of a patent labyrinth in the candidate ear and at least aidable hearing in the opposite ear, thus excluding patients who have undergone prior labyrinthectomy for unilateral Menière's disease that later progressed to bilateral vestibular hypofunction. Eight years after right unilateral labyrinthectomy, we implanted stimulating electrodes in the previously exenterated right ear ampullae of a rhesus macaque monkey. The left labyrinth had long-standing hypofunction due to intratympanic gentamicin injection and surgical disruption. We used three-dimensional video-oculography to measure eye movement responses to prosthetic electrical stimulation. We also measured head-movement responses to prosthetic stimulation with the head unrestrained. Bilateral vestibular hypofunction was confirmed by absence of vestibuloocular reflex responses to whole-body rotation without prosthetic stimulation. For a subset of the implanted electrodes, prosthetic vestibular stimulation evoked robust compensatory eye and head movements. One electrode reliably elicited responses aligned with the implanted ear's anterior canal nerve regardless of the return electrode used. Similarly, a second electrode also elicited responses consistent with excitation of the horizontal canal nerve. Responses grew quasilinearly with stimulation rate and current amplitude. Prosthetic electrical stimulation targeting the vestibular nerve can be effective years after labyrinthectomy, if at least some parts of the vestibular nerve's ampullary branches remain despite destruction or removal of the membranous labyrinth.

Management of Vestibular Schwannoma

Background Vestibular schwannoma (VS) is considered histologically a benign tumor and is currently preferred over the older term (Acoustic neuroma) as it usually arises from the inferior division of the vestibular nerve and not the acoustic nerve in the cerebellopontine angle. VS were one of the most common intra cranial tumors, comprising 8-10% of tumors in most series. Annual incidence is probably about 1.5 cases per 100,000 population, over the past couple decades this estimate has increased and the typical size at the initial diagnosis has decreased as a result of the advances in the MRI scans & CT scan qualities, (VS) is found to be occurring among middle age groups with no gender prevalence in the fourth or fifth decade. Aim of the Work To evaluate the VS management especially partial resection of large VS followed by gamma knife. Patients and Methods This study is a retrospective prospective study. This study was carried out at Al-Demerdash University hospital, the authority of specialized institutes and teaching hospitals and international medical Centre (Gamma knife department). Time of the study: from March 2019 till March 2021. Results In this study we found that according to the demographic, characteristics & personal history of the study group, it is noted that vestibular shwannoma is common among middle aged group (mean =41 years), with no substantial difference between genders (53% F & 47% M), we found that as regard the clinical picture, most of patients suffered from hearing loss as a complaint (88%) of about 3.5 months duration (median IQR) while all the patients (100%) had a sensory neural sensory loss and verified by PTA, SDT & word discrimination, tinnitus & unsteadiness were found in 70% & 50% respectively. This study has some limitations which are small populations of patients with vestibular schwannoma who generally have short follow-up. We include patients with heterogeneous tumors in regard to size and hearing status. Further studies needed with large populations to establish our results. Conclusion We concluded that considering the good tumor growth control and facial nerve function preservation as well as the possibility of preserving serviceable hearing and the low number of complications, subtotal resection followed by Gamma knife can be the treatment option of choice for large Vestibular schwannoma.

Characteristics of spontaneous nystagmus and its correlation to video head impulse test findings in vestibular neuritis.

To explore the direction and SPV (slow phase velocity) of the components of spontaneous nystagmus (SN) in patients with vestibular neuritis (VN) and the correlation between SN components and affected semicircular canals (SCCs). Additionally, we aimed to elucidate the role of directional features of peripheral SN in diagnosing acute vestibular syndrome. A retrospective analysis was conducted on 38 patients diagnosed with VN in our hospital between 2022 and 2023. The direction and SPV of SN components recorded with three-dimensional videonystagmography (3D-VNG) and the video head impulse test (vHIT) gain of each SCC were analyzed as observational indicators. We examined the correlation between superior and inferior vestibular nerve damage and the direction and SPV of SN components, and vHIT gain values in VN patients. The median illness duration of between symptom onset and moment of testing was 6 days among the 38 VN patients (17 right VN and 21 left VN). In total, 31 patients had superior vestibular neuritis (SVN), and 7 had total vestibular neuritis (TVN). Among the 38 VN patients, all had horizontal component with an SPV of (7.66 ± 5.37) °/s, 25 (65.8%) had vertical upward component with a SPV of (2.64 ± 1.63) °/s, and 26 (68.4%) had torsional component with a SPV of (4.40 ± 3.12) °/s. The vHIT results in the 38 VN patients showed that the angular vestibulo-ocular reflex (aVOR) gain of the anterior (A), lateral (L), and posterior (P) SCCs on the ipsilesional side were 0.60 ± 0.23, 0.44 ± 0.15 and 0.89 ± 0.19, respectively, while the gains on the opposite side were 0.95 ± 0.14, 0.91 ± 0.08, and 0.96 ± 0.11, respectively. There was a statistically significant difference in the aVOR gain between the A-, L-SCC on the ipsilesional side and the other SCCs (p < 0.001). The aVOR gains of A-, L-, and P-SCC on the ipsilesional sides in 31 SVN patients were 0.62 ± 0.24, 0.45 ± 0.16, and 0.96 ± 0.10, while the aVOR gains on the opposite side were 0.96 ± 0.13, 0.91 ± 0.06, and 0.98 ± 0.11, respectively. There was a statistically significant difference in the aVOR gain between the A-, L-SCC on the ipsilesional side and the other SCCs (p < 0.001). In 7 TVN patients, the aVOR gains of A-, L-, and P-SCC on the ipsilesional side were 0.50 ± 0.14, 0.38 ± 0.06, and 0.53 ± 0.07, while the aVOR gains on the opposite side were 0.93 ± 0.17, 0.90 ± 0.16, and 0.89 ± 0.09, respectively. There was a statistically significant difference in the aVOR gain between the A-, L-, and P-SCC on the ipsilesional side and the other SCCs (p < 0.001). The aVOR gain asymmetry of L-SCCs in 38 VN was 36.3%. The aVOR gain asymmetry between bilateral A-SCCs and bilateral P-SCCs for VN patients with and without a vertical upward component was 12.8% and 8.3%, which was statistically significant (p < 0.05). For VN patients with and without a torsional component, the aVOR gain asymmetry of bilateral vertical SCCs was 17.0% and 6.6%, which was statistically significant (p < 0.01). Further analysis revealed a significant positive correlation between the aVOR gain asymmetry of L-SCCs and the SPV of the horizontal component of SN in all VN patients (r = 0.484, p < 0.01), as well as between the asymmetry of bilateral vertical SCCs and the SPV of torsional component in 26 VN patients (r = 0.445, p < 0.05). However, there was no significant correlation between the aVOR gains asymmetry of bilateral A-SCCs and P-SCCs and the SPV of the vertical component in 25 VN patients. There is a correlation between the three-dimensional direction and SPV characteristics of SN and the aVOR gain of vHIT in VN patients. These direction characteristics can help assess different SCCs impairments in patients with unilateral vestibular diseases.

Metastasis Associated in Colorectal Cancer 1 (MACC1) mRNA Expression Is Enhanced in Sporadic Vestibular Schwannoma and Correlates to Deafness.

Vestibular schwannoma (VS) are benign cranial nerve sheath tumors of the vestibulocochlear nerve. Their incidence is mostly sporadic, but they can also be associated with NF2-related schwannomatosis (NF2), a hereditary tumor syndrome. Metastasis associated in colon cancer 1 (MACC1) is known to contribute to angiogenesis, cell growth, invasiveness, cell motility and metastasis of solid malignant cancers. In addition, MACC1 may be associated with nonsyndromic hearing impairment. Therefore, we evaluated whether MACC1 may be involved in the pathogenesis of VS. Sporadic VS, recurrent sporadic VS, NF2-associated VS, recurrent NF2-associated VS and healthy vestibular nerves were analyzed for MACC1 mRNA and protein expression by quantitative polymerase chain reaction and immunohistochemistry. MACC1 expression levels were correlated with the patients' clinical course and symptoms. MACC1 mRNA expression was significantly higher in sporadic VS compared to NF2-associated VS (p < 0.001). The latter expressed similar MACC1 concentrations as healthy vestibular nerves. Recurrent tumors resembled the MACC1 expression of the primary tumors. MACC1 mRNA expression was significantly correlated with deafness in sporadic VS patients (p = 0.034). Therefore, MACC1 might be a new molecular marker involved in VS pathogenesis.

Surgical Management of Vestibular Schwannomas: The Retrosigmoid Approach

This article is written to provide the reader with a comprehensive overview of the retrosigmoid approach to resection of a tumor at the cerebellopontine angle (CPA). Vestibular schwannoma is a benign tumor arising from either the superior or inferior vestibular nerves. These slow-growing tumors are initially clinically silent but eventually result in symptoms of hearing loss and imbalance, as they grow and compress surrounding cranial nerves and the brainstem. Observation, radiosurgery, and microsurgical resection are the 3 primary management strategies, and decision-making is highly nuanced and individualized to the patient.

Quantitative Evaluations of Vestibular Function in Patients With Petrous Apex Cholesterol Granulomas Treated With an Endoscopic Transsphenoidal Approach: A Report of Two Cases.

We report two cases of petrous apex cholesterol granuloma (PACG) treated with an endoscopic transsphenoidal approach. Vestibular functions of the two patients were evaluated quantitatively by video Head Impulse Test (vHIT) and/or vestibular evoked myogenic potentials (VEMPs). Two patients with PACG who experienced episodes of dizziness are presented. An endoscopic transsphenoidal approach to PACG. The preoperative and postoperative vestibular functions as evaluated by vHIT and VEMP. Two cases of PACG were treated by a transsphenoidal approach. The internal auditory canal was compressed by the PACG in both cases. The patients both experienced episodes of dizziness before surgery and preoperative vestibular testing including vHIT and VEMP indicated dysfunction of vestibular nerves. After surgery, their symptoms were completely resolved, and the vestibular testing results were improved. This article is noteworthy for being the first to publish quantitative vestibular function testing for patients with PACG with vestibular dysfunction. PACG may show various symptoms, with dizziness being one of the most common symptoms. In cases in which the internal auditory canal is compressed by the PACG, vestibular functions should be evaluated by vHIT and VEMP. In the present cases, dizziness was found to be resolved by surgery to release the compression on internal auditory canal. Based on the present cases, the transsphenoidal approach is considered to be both safe and effective.

Vestibular Nucleus Involvement in Patients With Acute Vertigo Due to Herpes Zoster Oticus or Vestibular Neuritis.

Herpes zoster oticus (HZO) typically provokes vestibular symptoms and is traditionally viewed as a cranial nerve equivalent of shingles, but in contrast to vestibular neuritis (VN), it is unclear whether the pathology of HZO is limited to the vestibular nerve (neuritis) or can also involve the brainstem (nucleitis). We retrospectively compared brain MRIs of patients with HZO with those of patients with VN to study radiologic changes in the brainstem. Five of 10 patients with HZO showed signal abnormalities in the vestibular nuclei, which lie in multiple vascular territories, whereas no patients with VN exhibited such findings. HZO may at least in part reflect vestibular nucleitis, as opposed to a pure neuritis.

Novel SOX10 indel mutations drive schwannomas through impaired transactivation of myelination gene programs.

Schwannomas are common peripheral nerve sheath tumors that can cause severe morbidity given their stereotypic intracranial and paraspinal locations. Similar to many solid tumors, schwannomas and other nerve sheath tumors are primarily thought to arise due to aberrant hyperactivation of the RAS growth factor signaling pathway. Here, we sought to further define the molecular pathogenesis of schwannomas. We performed comprehensive genomic profiling on a cohort of 96 human schwannomas, as well as DNA methylation profiling on a subset. Functional studies including RNA sequencing, chromatin immunoprecipitation-DNA sequencing, electrophoretic mobility shift assay, and luciferase reporter assays were performed in a fetal glial cell model following transduction with wildtype and tumor-derived mutant isoforms of SOX10. We identified that nearly one-third of sporadic schwannomas lack alterations in known nerve sheath tumor genes and instead harbor novel recurrent in-frame insertion/deletion mutations in SOX10, which encodes a transcription factor responsible for controlling Schwann cell differentiation and myelination. SOX10 indel mutations were highly enriched in schwannomas arising from nonvestibular cranial nerves (eg facial, trigeminal, vagus) and were absent from vestibular nerve schwannomas driven by NF2 mutation. Functional studies revealed these SOX10 indel mutations have retained DNA binding capacity but impaired transactivation of glial differentiation and myelination gene programs. We thus speculate that SOX10 indel mutations drive a unique subtype of schwannomas by impeding proper differentiation of immature Schwann cells.

Literature review and two study cases of vestibular paroxysmia from an otorhinolaryngology centre

IntroductionVestibular paroxysmia is a rare disorder of the balance system manifested by recurrent attacks of vertigo, the etiology of which is associated with compression of a blood vessel on the vestibulocochlear nerve. The exact mechanism for triggering the symptoms is not fully understood. The condition occurs in all age groups and without gender predilection. The purpose of the study was to review the literature on vestibular paroxysmia, discuss criteria for the diagnosis of the disease, diagnostic management, proposed therapy, and present clinical cases from the authors’ own practice.Material and methodsA review of the scientific literature was conducted via the PubMed database using the keywords “vestibular paroxysmia,” “neurovascular conflict cochlear nerve,” and “neurovascular conflict vestibular nerve”. PRISMA guidelines for systematic reviews were applied.ResultsThere were 146 publications found; after analysis of titles and abstracts, 56 were included in the review; another 10 manuscripts were identified during reference review. Among them, 11 studies were devoted to diagnostic imaging, 19 described the clinical course of the condition based on retrospective studies, 15 were case reports, and 11 other reports and reviews. Following evaluation of this literature, two clinical cases of vestibular paroxysm from the authors’ own practice are described. These cases are presented along with their diagnosis and therapy.ConclusionsImaging studies are of significant value in diagnosing many vascular–neural conflicts, but for vestibular paroxysmia the diagnosis is made on the basis of clinical symptoms and according to the division proposed by the Bárány Society in 2016. Pharmacological therapy is recommended, and response to therapy is one of the criteria for diagnosing the condition. Surgical treatment is reserved for the most severe cases.

Bilateral vision loss as first presentation of vestibular schwannoma

Abstract Vestibular schwannoma is a benign, slow-growing tumor of the vestibular nerve, located at cerebellopontine angle. It is derived from the Schwann cells of the myelin sheath of cranial nerve eight. We present here a unique case of vestibular schwannoma, who visited us with a primary complaint of bilateral decreased vision. Detailed examination revealed bilateral papilloedema associated with right-sided cranial nerve five and eight involvements. Patient was operated for the right-sided cerebellopontine angle tumor under intraoperative neuromonitoring. Postoperatively, patient showed significant improvement, both symptomatically and clinically.

Motion Tracking in Diagnosis: Gait Disorders Classification with a Dual-Head Attentional Transformer-LSTM

Gait and motion stability analysis in gait dysfunction problems is a very interesting research area. Usually, patients who undergo vestibular deafferentation are affected by changes in their dynamic balance. Therefore, it is important both patients and physicians are able to monitor the progress of the so-called vestibular compensation to observe the rehabilitation process objectively. Currently, the quantification of their progress is highly dependent on the physician’s opinion. In this article, we designed a novel methodology to classify the gait disorders associated with unilateral vestibular deafferentation in patients undergoing vestibular schwannoma surgery (model of complete vestibular loss associated with imbalance due to vestibular nerve section and eventual labyrinthectomy). We present a dual-head attentional transformer-LSTM (DHAT-LSTM) to evaluate the problem of rehabilitation from gait dysfunction, which is observed by a Kinect. A system consisting of a key-point-RCNN detector is used to compute body landmark measures and evaluate gait dysfunction based on a DHAT-LSTM network. This structure is used to quantitatively assess gait classification by tracking skeletal features based on the temporal variation of feature sequences. The proposed deep network analyses the features of the patient’s movement. These extracted high-level representations are then fed to the final evaluation of gait dysfunction. The result analytically demonstrates its effectiveness in classification evaluation when used in conjunction with state-of-the-art pose estimation and feature extraction techniques. An accuracy greater than 81% was achieved for given sets of individuals using velocity-based, angle-based, and position features for both the whole body and the symmetric features of the body.

0394 Effect of electrical vestibular nerve stimulation on sleep quality in young adults with insomnia: a randomized controlled trial

Abstract Introduction Insomnia is a common sleep disorder among all age groups which adversely affects physical and mental health. Young adults are considered a high-risk population group due to increased use of electronic media at bedtime, stress associated with balancing educational demands and unhealthy sleep practices. Previous research suggests that electrical vestibular nerve stimulation (VeNS) may improve sleep outcomes by influencing the hypothalamus and brainstem nuclei involved in regulating the circadian rhythm and wakefulness. The present study is a randomised, double blinded, sham-controlled trial with the aim of assessing the efficacy of VeNS on the sleep quality of young adults suffering from insomnia. Methods Eighty adults aged 18-24 years who scored 15 or higher on the Insomnia Severity Index (ISI) were recruited. Participants assigned to the intervention group (n=40) received 30 minutes per day of VeNS with 5 sessions per week for 4 weeks, while the control group (n=40) received sham stimulation for the same period. ISI scores were recorded at baseline and repeated weekly. The primary outcome was between-group change in ISI from baseline to day 28. Secondary outcomes included between-group change in the emotional states of depression, anxiety and stress measured by the DASS-21 questionnaire, and quality of life (QoL) measured by the WHOQoL-BREF. Results A group-by-time interaction effect on change in ISI score from day 0 to day 28 (F3, 248 = 295.56; P&amp;lt; 0.001) was observed. The intervention group had a higher reduction in mean ISI score relative to the control group at day 28 (mean change [95% CI]: 7.23 [6.78, 7.67] vs. 0.98 [0.89, 1.06], P&amp;lt; 0.001; respectively). Furthermore, the intervention group showed improvements in depression, anxiety, and stress scores (P&amp;lt; 0.001) and QoL outcomes (P&amp;lt; 0.001) compared with the control group. Conclusion Regular VeNS usage over 4 weeks lead to a clinically meaningful decrease in ISI scores and improved general well-being in young adults with insomnia. VeNS may have potential as a drug-free and non-invasive therapy to improve sleep outcomes. Support (if any)

0396 Efficacy of electrical vestibular nerve stimulation for the management of insomnia: a randomized controlled trial

Abstract Introduction Insomnia is one of the most prevalent health concerns in the general population. Cognitive behavioural therapy (CBT) and pharmacological interventions are recommended for the treatment of insomnia. However, CBT can be expensive and difficult to access, while the use of pharmacotherapy can be limited by reports of adverse events. Due to these limitations, there is a strong need for alternative measures to manage insomnia. Preliminary research indicates the potential that electrical vestibular nerve stimulation (VeNS) has as a non-invasive method for managing insomnia. The aim of this study is to evaluate the efficacy of VeNS as a method of managing sleep quantity and quality in individuals with insomnia, as compared to a sham control. Methods The study was a two-armed, double-blind randomized controlled trial that was conducted across two research sites in the United Kingdom (UK) and Hong Kong (HK). Participants aged over 18 years with an Insomnia Severity Index (ISI) score of 15 or higher were randomly assigned to intervention and control groups. The intervention group was instructed to use the VeNS device at home for 30 minutes daily for 4 weeks, while the control group was instructed to use the sham device for the same period. ISI values were captured at baseline, at 2 weeks and at 4 weeks. Sleep quality and quality of life (QoL) were assessed at baseline and at 4 weeks using the Pittsburgh Sleep Quality Index (PSQI) and the 36-item Short Form Health Survey (SF-36), respectively. Results A total of 146 participants were recruited from the HK (n=94) and UK (n=52) research sites. The study has recently been completed with the statistical analysis ongoing. The between-group change in ISI values (primary outcome), sleep quality and QoL from baseline to week 4 will be examined. Conclusion The results of this study will help determine whether the relatively inexpensive, and non-invasive technique of VeNS is effective in the management of insomnia. The data collected will be used to support regulatory submissions, primarily to the US Food and Drug Administration. Support (if any)

Abnormal Nystagmus Induced by Peripheral Vestibular Disorders

Electrophysiological measurement of the eye rotation axis using stimulation of a single semicircular canal nerve showed that the eye rotated around the axis perpendicular to the plane of the stimulated semicircular canal. Therefore, the affected semicircular canal can be identified by analyzing the eye rotation axis in cases of abnormal nystagmus. When the main component of the abnormal nystagmus is horizontal, the origin of the nystagmus is the lateral semicircular canal. When the main component of the abnormal nystagmus is torsional, the origin of the nystagmus is the anterior and/or posterior semicircular canal. The eye rotation axis in cases of excitatory nystagmus is quite the same as that in cases of inhibitory nystagmus, although the direction of eye rotation is opposite between cases of excitatory and inhibitory nystagmus. Vestibular neuritis mostly involves the superior vestibular nerve. The superior vestibular nerve transmits sensory information transmitted by from the vestibular hair cells located in the anterior and lateral semicircular canals. Therefore, patients with vestibular neuritis exhibit nystagmus with both horizontal and torsional components caused by inhibition of both the anterior and lateral semicircular canals. In patients with Ménière's disease, during a vertigo attack, excitatory nystagmus of anterior and/or posterior and/or lateral semicircular canal origin can be seen. Because the involving ratio of each contributing ratios of the three semicircular canals to nystagmus can vary, the ratio of the torsional component of the nystagmus to the horizontal component also varies. While nystagmus is purely horizontal in some cases, it is purely torsional in others. In the posterior canal type of BPPV, during the Dix-Hallpike maneuver, transient torsional nystagmus with the torsional component directed toward the affected side can be seen. In the lateral canal type of BPPV (canalolithiasis), geotropic positional nystagmus can be seen when the patient is supine. In the lateral canal type of BPPV (cupulolithiasis), apogeotropic positional nystagmus can be seen when the patient is supine.

Acute psychosis as initial presentation for Neurofibromatosis Type 2 (P11-9.006)

<h3>Objective:</h3> To describe the clinical course of a pediatric patient presenting with acute auditory hallucinations with workup revealing a new diagnosis of NF2. <h3>Background:</h3> NF2 is an autosomal dominant neurocutaneous disorder characterized by vestibular schwannomas, meningiomas, neurofibromas, gliomas, cerebral calcifications, cataracts, and cognitive impairment. Acute onset psychosis is an uncommon sequela of NF2, and if present, is usually attributed to the known prior history of NF2. However, here we present a case of acute psychosis that precipitated the <i>initial</i> diagnosis of NF2. <h3>Design/Methods:</h3> NA <h3>Results:</h3> A 13-year-old Hispanic male with no known intracranial tumors or other neurocutaneous stigmata presented with acute-onset psychosis, agitation, delusions, and painless monocular vision loss. Upon further review, he was reported to have a remote history of morning headaches, right upper extremity weakness and paresthesias thought to be due to a trampoline accident, and multiple dermal lesions that were diagnosed as pilonidal cysts despite biopsy and sectioning. He presented with complaints of hearing a constant “airplane sound,” poor sleep, agitation, persecutory delusions and paranoia, pressured speech, and discontinuity of thought. On exam, he was agitated and not oriented to situation, responding rapidly to questions with the incorrect answer, hyperkinetic, and generally distressed and labile. MRI brain with and without contrast demonstrated bilateral enhancing vestibular schwannomas, a meningioma, and nerve sheath tumor, all radiographically diagnostic for NF2. Though he was initially treated empirically for encephalitis with steroids, he improved rapidly upon initiation of antipsychotics; all other workup for the psychosis was unremarkable and a pathogenic variant of NF2 was confirmed. <h3>Conclusions:</h3> It is important to look for stigmata of NF2 in patients with psychosis as bilateral vestibular schwannomas can cause auditory hallucinations secondary to continuous tinnitus. Early identification of NF2 will lead to targeted therapeutic/surgical intervention that may relieve cranial nerve compression and thus reduce the odds of developing psychosis. <b>Disclosure:</b> Dr. Domingue has nothing to disclose. Dr. Sandweiss has nothing to disclose. Dr. Salazar has nothing to disclose. Dr. Gill has received personal compensation in the range of $500-$4,999 for serving as an Expert Witness for Elite Medical Experts. The institution of Dr. Gill has received research support from NIH-NINDS.

A randomized controlled trial to evaluate the efficacy of electrical vestibular nerve stimulation (VeNS), compared to a sham control for the management of sleep in young adults.

Preliminary research suggests that electrical vestibular nerve stimulation (VeNS) may improve sleep outcomes by influencing the hypothalamus and brainstem nuclei involved in regulating the circadian rhythm and wakefulness. This randomised, sham-controlled trial aimed to assess the effectiveness of VeNS on insomnia in young adults. Eighty adults aged 18-24 years were randomly allocated to the intervention (n=40) and control groups (n=40). The intervention group was provided with 30min per day of VeNS with five sessions weekly for four weeks, while the control group received sham stimulation for the same period. Baseline Insomnia Sleep Index (ISI) scores were recorded weekly. At baseline and at day 28, questionnaires to evaluate emotional states of depression, anxiety and stress, and quality of life (QoL) were completed. The primary outcome was change in ISI with comparison between baseline and day 28. The VeNS group significantly reduced their mean ISI score after 7days usage (p<0.001). At day 28 it was found that mean ISI scores had reduced from 19 to 11 in the VeNS group, and from 19 to 18 in the sham group, and the difference between the groups was significant (p<0.001). Moreover, application of VeNS appeared to significantly improve emotional state and QoL outcomes. This trial demonstrates that regular VeNS usage over four weeks leads to a clinically meaningful decrease in ISI scores in young adults with insomnia. VeNS may have potential as a drug-free and non-invasive therapy to improve sleep outcomes by positively influencing the hypothalamic and brainstem nuclei.

Application of vestibular function examination in the analysis of damaged site in patients with acute vestibular neuritis

Objective:To analyze the site of vestibular nerve damaged in patients with acute vestibular neuritis. Methods:Fifty-seven patients with acute vestibular neuritis were recruited, and each patient underwent caloric irrigation test, video head impulse test（vHIT） and vestibular evoked myogenic potentials（VEMPs）. The results were further analyzed. Results:Analysis of abnormal rates of different vestibular function tests: the abnormal rate of caloric irrigation test, horizontal semicircular canal vHIT, anterior semicircular canal vHIT, and posterior semicircular canal vHIT were 92.98%, 92.98%, 92.98%, and 52.63%, respectively. The abnormal rate of cervical vestibular evoked myogenic potentials（cVEMP） and ocular vestibular evoked myogenic potentials（oVEMP） were 52.63% and 89.47%. The abnormal rate of caloric irrigation test, horizontal semicircular canal vHIT, anterior semicircular canal vHIT, and oVEMP were significantly higher than posterior semicircular canal vHIT and cVEMP（P<0.01）. Combination analysis of different vestibular function tests: there are twenty-six patients（45.61%, superior and inferior vestibular nerve） with abnormal caloric irrigation test, video head impulse test, and VEMPs. There are twenty-five patients（43.86%, superior vestibular nerve） with abnormal caloric irrigation test, horizontal semicircular canal vHIT, anterior semicircular canal vHIT, and oVEMP. There are 4 patients（7.02%, inferior vestibular nerve） with abnormal posterior semicircular canal vHIT and cVEMP. There are two patients（3.51%, ampullary vestibular nerve） with abnormal caloric irrigation test, horizontal semicircular canal vHIT, and anterior semicircular canal vHIT. The rate of superior and inferior vestibular neuritis and superior vestibular neuritis were significantly higher than inferior vestibular neuritis and ampullary vestibular neuritis（P<0.01）. Conclusion:Acute vestibular neuritis subtypes can be divided into four categories: superior and inferior vestibular neuritis, superior vestibular neuritis, inferior vestibular neuritis, and ampullary vestibular neuritis. Video head impulse test can accurately assess the site of vestibular nerve damage in patients with acute vestibular neuritis. In addition, vHIT combined with VEMPs can provide objective evidence for the diagnosis of ampullary vestibular neuritis.

Serum/glucocorticoid-inducible kinase 1 deficiency induces NLRP3 inflammasome activation and autoinflammation of macrophages in a murine endolymphatic hydrops model

Ménière’s disease, a multifactorial disorder of the inner ear, is characterized by severe vertigo episodes and hearing loss. Although the role of immune responses in Ménière’s disease has been proposed, the precise mechanisms remain undefined. Here, we show that downregulation of serum/glucocorticoid-inducible kinase 1 is associated with activation of NLRP3 inflammasome in vestibular-resident macrophage-like cells from Ménière’s disease patients. Serum/glucocorticoid-inducible kinase 1 depletion markedly enhances IL-1β production which leads to the damage of inner ear hair cells and vestibular nerve. Mechanistically, serum/glucocorticoid-inducible kinase 1 binds to the PYD domain of NLRP3 and phosphorylates it at Serine 5, thereby interfering inflammasome assembly. Sgk−/− mice show aggravated audiovestibular symptoms and enhanced inflammasome activation in lipopolysaccharide-induced endolymphatic hydrops model, which is ameliorated by blocking NLRP3. Pharmacological inhibition of serum/glucocorticoid-inducible kinase 1 increases the disease severity in vivo. Our studies demonstrate that serum/glucocorticoid-inducible kinase 1 functions as a physiologic inhibitor of NLRP3 inflammasome activation and maintains inner ear immune homeostasis, reciprocally participating in models of Ménière’s disease pathogenesis.

Cochlear Implantation in Intralabyrinthine Schwannoma: Case Series and Systematic Review of the Literature

Intralabyrinthine schwannomas (ILS) are rare benign tumours arising from the peripheral branches of the cochlear or vestibular nerves in the membranous labyrinth, intracochlear schwannomas being the most frequent ones. When hearing is no longer feasible on the affected side, surgical removal along with simultaneous cochlear implantation can be proposed to the patient. We hereby present a systematic review of the literature on the topic, as well as two original cases from our centre (Ospedale Università degli Studi di Padova). Cochlear implantation in intracochlear schwannomas is feasible, with overall satisfactory hearing outcomes in accordance with the evidence found in the literature.