Objectives Inner ear ischemic animal models using photochemical reactions have been devised in various ways. Localized vascular ischemia occurs with 532-nm laser irradiation after systemic rose bengal injection, a known photothrombotic mechanism. The aim of this study is to evaluate a photothrombosis-induced vestibulopathy mimicking behavioral changes in the inner ear ischemia model.
Methods Seven-week-old male Spraque-Dawley rats were used. Animals were divided into three groups: control group (n=6), sham laser group (n=9), and laser group (n=9). To induce the photothrombosis, animals were injected with rose bengal into the femoral vein and then were irradiated with a 532-nm laser (175 mW for 900 seconds) via transtympanic membrane. To investigate the vestibulopathy after photothrombosis, the behavior tests (tail lift reflex test, air righting reflex test, rotarod test) were performed on the 1st, 3rd, and 7th days after surgery. Additionally, an open field test was conducted and analyzed using EthoVision XT (Noldus).
Results The laser group exhibited significant behavioral change to mimic vestibulopathy in all assessments. Inducing photothrombosis with rose bengal caused severe gait instability, which precluded rotarod testing. In the tail lift reflex test, the laser group displayed vestibular dysfunction with a lower angle formation compared to the control rats. During the open field test, the laser group exhibited reduced mobility, a condition that persisted in the laser groups for 7 days.
Conclusions Noninvasive laser irradiation using rose bengal and a 532-nm laser induces photothrombosis in the inner ear of animals, leading to the development of vestibulopathy mimicking imbalanced behavior.
Objectives This study was performed to investigate the efficacy of the fixation index (FI) of the bithermal caloric test for differentiating brain lesions in vestibular disorder.
Methods We reviewed the medical records of 286 consecutive dizzy patients who underwent brain magnetic resonance imaging (MRI) and the bithermal caloric test at department of otorhinolarnygology. Central vestibulopathy (CVP) was defined as when corresponding lesion was identified on brain MRI, otherwise peripheral vestibulopathy (PVP) was defined. The FI was defined as the mean slow phase velocity (SPV) with fixation divided by the mean SPV without fixation, and failure was indicated when the FI exceeded 70%.
Results The CVP confirmed by brain MRI and PVP were 16.8% and 83.2%, respectively. The most common CVPs were cerebellopontine angle tumor (n=19, 39.6%) and chronic cerebellar infarction (n=18, 37.5%). There were 23 cases of CVP (47.9%) and 47 cases of PVP (19.7%) with abnormal number of FI in at least two of the four caloric irrigations. The FI score of right cool (RC), left cool (LC), and right warm (RW) were also increased significantly in patients with CVP (p=0.031 at RCFI, p=0.014 at LCFI, p=0.047 at RWFI, and p=0.057 at LWFI; Mann-Whitney U-test).
Conclusions If two or more abnormal FIs are detected during bithermal caloric testing, there is a high likelihood of CVP. Consequently, additional brain MRI may be necessary for further evaluation.
Superficial siderosis (SS) is a rare neurodegenerative condition characterized by hemosiderin deposition in the central nervous system, which sometimes leads to sensorineural hearing loss and vestibular dysfunction. This case report details the diagnosis and treatment of a 63-year-old female patient presenting with a yearlong history of postural instability and recent symptoms of sudden right-sided hearing loss and imbalance. Physical examination and imaging revealed bilateral deafness and infratentorial SS. Treatment, including medication, vestibular exercises, high-dose steroids, and hyperbaric oxygen therapy, led to a significant alleviation of dizziness but no improvement in hearing. This case emphasizes the need for clinicians to consider SS in patients presenting with sudden-onset hearing loss and dizziness, even without prior any medical history or trauma, to accurately identify the underlying cause.
Distinguishing central and peripheral causes of dizziness is vital. A case is presented where a 42-year-old man with a history of posterior circulation ischemic stroke developed acute unilateral vestibulopathy with hearing loss. Clinical examination revealed signs of vestibular dysfunction on the left side. Audiometry confirmed deafness on the left, but imaging ruled out new central issues. The patient was diagnosed with audiovestibulopathy and treated with steroids, antiviral agents, intratympanic injections, and hyperbaric oxygen therapy. Hearing loss persisted, but dizziness improved with vestibular rehabilitation. Poststroke patients should be closely monitored for peripheral complications. Further research should explore the benefits of antiplatelet therapy in vascular-related conditions, even without clear central lesions.
Objectives Big data analytics in healthcare research have gained momentum, offering unprecedented opportunities to investigate complex medical conditions like acute vestibular neuritis (AVN). However, an inappropriate definition can introduce bias and inaccuracies into prevalence estimation, making the results unreliable and hindering cross-study comparisons. The Health Insurance data in South Korea will be used to create a robust operational definition for AVN.
Methods The study utilized the National Patients Sample dataset from the Health Insurance Review and Assessment Service (HIRA) of the Republic of Korea. The operational definition of AVN was defined using the HIRA data, which includes specific codes for diagnosis, testing, and medications. The revised categorization scheme for AVN was presented as case 1 through case 5, with criteria for each category.
Results The optimal conditions are deemed to be those that encompass the outcomes of both case 5 and case 1-1, encompassing all conditions. The study also provided prevalence estimates for subgroups based on demographic factors (age, sex), and found a consistent pattern throughout all years, sex, and age.
Conclusions The study analyzed the prevalence of AVN in case 1 and case 5, which were similar to the reference prevalence of 3.5 per 100,000 people reported in other countries. The study’s results are encouraging for several reasons, including the validity of the operational definitions used, and the agreement between the study’s prevalence estimates and the reference prevalence. The operational definition in statistics, in the context of big data, serves as a precise and standardized criterion.
Thiamine deficiency may cause Wernicke encephalopathy (WE) characterized by ataxia, ophthalmoplegia, and confusion. Aside from the triad of cardinal symptoms, selective or predominant impairments of bilateral horizontal canals may be observed in WE. Here, we report a patient with gastric mucosa-associated lymphoid tissue (MALT)-lymphoma complicated by an early stage of WE due to thiamine deficiency manifesting bilateral vestibular dysfunctions. A 78-year-old man recently diagnosed gastric MALT-lymphoma presented with dizziness and disequilibrium for several weeks. He showed mild imbalance while tandem walking and abnormal catch-up saccades bilaterally during bedside head impulse test (HIT). Video HIT revealed decreased vestibulo-ocular reflex gains with catch-up saccades for the bilateral horizontal and several vertical canals. Diagnostic work-up demonstrated decreased serum thiamine and lesions in the mammillary body and periaqueductal gray matter on brain magnetic resonance images. Furthermore, with thiamine replacement, his clinical symptoms were markedly improved. Also, vestibular symptoms and signs may be an early manifestation of WE, and video HIT could be a useful diagnostic tool to aid early detections.
Objectives The objective of this study was to analyze vestibulocochlear function results in patients identified with isolated semicircular canal (SCC) hypofunction using the video head impulse test (vHIT).
Methods A retrospective review was conducted on the clinical records of 123 patients diagnosed with isolated SCC hypofunction based on vHIT results. Among these patients, 72 had isolated posterior SCC (PSCC) hypofunction, 25 had isolated lateral SCC (LSCC) hypofunction, and 26 had isolated anterior SCC (ASCC) hypofunction. Descriptive analyses were performed on various vestibulocochlear tests including pure tone audiometry, sinusoidal harmonic acceleration (SHA), spontaneous nystagmus (SN), head-shaking nystagmus (HSN), caloric testing, and cervical vestibular evoked myogenic potential, with results analyzed separately for each SCC hypofunction group.
Results The study found that 66.0% of the evaluated patients exhibited abnormal results in at least one vestibulocochlear function test. PSCC hypofunction patients showed a significantly higher incidence of hearing loss compared to ASCC and LSCC hypofunction patients. LSCC hypofunction patients exhibited higher rates of corrective saccade, phase asymmetry of SHA, and SN abnormalities compared to other SCC hypofunction patients. Additionally, the rates of corrective saccade and phase asymmetry of SHA were also higher in LSCC hypofunction patients. ASCC hypofunction patients demonstrated significantly higher rates of normal corrective saccade, phase lead of SHA, and SN.
Conclusions The analysis of this study suggests that even in cases where vHIT indicates isolated SCC hypofunction, additional vestibulocochlear function tests should be conducted to identify any associated vestibulocochlear dysfunctions. This highlights the importance of comprehensive evaluation to accurately diagnose and manage patients with SCC hypofunction.
Objectives Vestibular epilepsy refers to epilepsy in which vertigo is the sole or main symptom of a seizure. However, epilepsy is rarely considered as a differential diagnosis in patients complaining of dizziness. Here, we reviewed ten cases of vestibular epilepsy and analyzed the dizziness complained by the patient.
Methods In this study, the medical records of dizziness patients with epileptic discharges observed on electroencephalogram were retrospectively analyzed. Patients who had other obvious causes of dizziness, lacked a description of dizziness, or were not taking antiseizure medications were excluded. We finally recruited 10 patients, and investigated their dizziness characteristic, brain imaging tests, electroencephalograms, and blood test findings.
Results Patients with vestibular epilepsy usually felt dizzy abruptly while not moving, and often complained of dizziness in the form of spinning around or becoming dazed. Dizziness was short, usually between a few seconds and a few minutes, and the frequency of occurrence was variable, so there was no consistent trend. There were no abnormal findings in blood tests. In brain imaging test, most patients did not show significant abnormalities. The electroencephalographic abnormalities of the patients were mainly observed in the temporal lobe, and the dizziness they complained of improved when they started taking antiseizure medications.
Conclusions If a patient with dizziness complains of dizziness that occurs suddenly and lasts for a short time, early electroencephalogram should be considered to prevent the diagnosis of epilepsy from being overlooked or delayed.
Objectives This study was performed to evaluate the difference of the cervical vestibular evoked myogenic potentials (cVEMP) stimulated by bone-conduction (BC) and air-conduction (AC) in patients with nonspecific dizziness.
Methods Twenty-eight dizzy patients (56 ears) and 15 subjects (30 ears) as normal control was enrolled. Responses of BC- and AC-cVEMP were recorded sequentially in both groups. cVEMP parameters including latencies, inter-latencies intervals, amplitudes, and interaural amplitude asymmetry were analyzed and compared.
Results Among the patients with nonspecific dizziness, AC-cVEMP responses were clearly detected in all 56 ears while BC-cVEMP responses were detected in 32 ears (57.1%). Amplitudes of BC-cVEMP were significantly smaller than those of AC-cVEMP in all patients with BC-cVEMP response. There was no difference in latencies, inter-latencies intervals, and interaural amplitude asymmetry ratios between BC- and AC-cVEMP. There was no significant difference in BCand AC-cVEMP between the dizzy and control groups.
Conclusions BC-cVEMP is not clinically useful in comparison to AC-cVEMP for the evaluation of nonspecific dizziness. An effective stimulation tool for BC is necessary to provoke more reliable responses of BC-cVEMP.
Objectives The slippage of the video-nystagmography devices causes motion artifacts in the trajectory of the pupil and thus results in distortion in the nystagmus waveform. In this study, the moving average was proposed to reduce slippage-induced motion artifacts from the real-world data obtained in the field.
Methods The dataset consists of an infrared video of positional tests performed on eight patients with a lateral semicircular canal benign paroxysmal positional vertigo. The trajectories of the pupil were obtained from the video with binarization, morphological operation, and elliptical fitting algorithm. The acquired data was observed and the section where the slippage occurred was labeled by an otolaryngologist. The moving average with windows of various lengths was calculated and subtracted from the original signal and evaluated to find the most adequate parameter to reduce the motion artifact.
Results The period of nystagmus in the given data was found to be ranged from 0.01 to 4 seconds. The slippages that appeared in the data can be categorized into fast and slow slippages. The length, distance, and speed of trajectories in the slippage ranges were also measured to find the characteristics of the motion artifact in video-nystagmography data. The shape of the nystagmus waveform was preserved, and the motion artifacts were reduced in both types of slippages when the length of the window in moving average was set to 1 second.
Conclusions The algorithm developed in this study is expected to minimize errors caused by slippage when developing a diagnostic algorithm that can assist clinicians.
Coronavirus disease 2019 (COVID-19) spread rapidly and was declared a pandemic. In this situation, vaccination for COVID-19 is important and has been prompted in many countries. However, a number of adverse events have been reported for the Pfizer, Moderna, and AstraZeneca vaccines. Otolaryngologic adverse events after COVID-19 vaccination were reported, including several cases of sudden sensorineural hearing loss. Vestibular neuritis (VN) is an acute vestibular syndrome that causes acute and spontaneous vertigo due to unilateral vestibular deafferentiation, leading to nausea or vomiting and unsteadiness that can last from days to weeks. Neurotropism for the cochleovestibular nerve, immunoglobulin G mediated immune off-target reaction, and reactivation of latent viruses are hypothesized to be etiologies. Herein, the case of a 49-year-old female who developed VN after COVID-19 vaccination is presented. Although the association between VN and COVID-19 vaccination remains unclear, clinicians should be aware that VN may occur as an adverse event of COVID-19 vaccination.
Objectives This study aims to investigate the usefulness of the video head impulse test (vHIT) as a method for evaluating vestibular function in patients with unilateral chronic middle ear disease.
Methods Nineteen patients with various unilateral middle ear diseases including chronic otitis media (COM), COM with cholesteatoma, and adhesive otitis media successfully underwent preoperative vHIT. The gain of vestibuloocular reflex (VOR) and the presence of corrective saccades were compared between the affected ear and the healthy ear.
Results A total of eight male and 11 female patients with a mean age of 43.1 years were included in this retrospective study. Twelve ears had COM, four had COM with cholesteatoma, and three had adhesive otitis media. A positive history of vertigo or dizziness was reported in 36.8% of the cases. The VOR gain of the affected ears and the healthy ears were 0.97±0.16 vs. 1.00±0.08 in the horizontal canal, 0.91±0.11 vs. 0.87±0.11 in the anterior canal, and 0.87±0.17 vs. 0.99±0.12 in the posterior canal, respectively. Only VOR gain of the posterior canal was significantly decreased compared with healthy ears.
Conclusions The average VOR gains in the patients with chronic middle ear disease were within the pre-defined values of normality; however, when compared quantitatively, posterior canal gain of affected ears was significantly decreased compared to healthy ears. Our results can be explained by the anatomical proximity of the ampulla of the posterior canal and middle ear space.
Objectives Vestibular schwannoma (VS) is a benign Schwann cell-derived slow growing tumor originating from the vestibular nerve. Here, we aimed to investigate the correlation between the presence of the dizziness symptoms and several vestibular function test results.
Methods We analyzed 32 patients who diagnosed with VS from 2010 to 2021 in our hospital. Caloric test, cervical vestibular-evoked myogenic potential (cVEMP) test, and video head impulse test (vHIT) were analyzed.
Results Age, sex, pure tone audiometry, and tumor size did not show any statistical significance according to the presence or absence of dizziness. There was also no association between the presence of dizziness symptom or dizziness type and the results of the caloric test, vHIT, and cVEMP test, respectively. However, patients with dizziness had a higher rate of tumors confined to the inner auditory canal than those without dizziness.
Conclusions In this study, the rate of complaints of dizziness was higer in patients with intracanalicular VS. The diagnostic role of vestibulsr function tests in VS is limited. The dissociation of the results of caloric test, vHIT, and cVEMP test suggest that these test are complementary.
Vestibular migraine (VM) is a variant of migraine resulting in vestibular symptoms in addition to symptoms typical of migraine. However, without a biomarker or a complete understanding of the pathophysiology, VM remains underrecognized and underdiagnosed. Therefore, the diagnosis of VM is still challenging. Meanwhile, VM should be clearly differentiated from other similar diseases. Here, we highlight these challenges, discuss common vestibular symptoms and clinical presentations in VM, and review the current aspects of its clinical diagnosis and evaluation. The concepts related to the treatment of VM are also discussed.
Objectives The aim of this study was to develop a filtering algorithm for raw nystagmus images and a diagnostic assistive algorithm using a principal component analysis (PCA) to distinguish the different types of benign paroxysmal positional vertigo (BPPV).
Methods Fifteen video clips of clinical data with typical nystagmus patterns of BPPV (13 cases) and with normal nystamgmus (two cases) were preprocessed when applied the thresholding, morphology operation, residual noise filtering, and center point extraction stages. We analyzed multiple data clusters in a single frame via a PCA; in addition, we statistically analyzed the horizontal and vertical components of the main vector among the multiple data clusters in the canalolithiasis of the lateral semicircular canal (LSCC) and the posterior semicircular canal (PSCC).
Results We obtained a clear imaginary pupil and data on the fast phases and slow phases after preprocessing the images. For a normal patient, a round shape of clustered dots was observed. Patients with LSCC showed an elongated horizontal shape, whereas patients with PSCC showed an oval shape at the (x, y) coordinates. The scalar values (mm) of the horizontal component of the main vector when performing a PCA between the LSCC- and PSCC-BPPV were substantially different (102.08±20.11 vs. 32.36±12.52 mm, respectively; p=0.0012). Additionally, the salar ratio of horizontal to vertical components in LSCC and PSCC exhibited a significant difference (16.11±10.74 mm vs. 2.61±1.07 mm, respectively; p=0.0023).
Conclusions The data of a white simulated imaginary pupil without any background noise can be a separate monitoring option, which can aid clinicians in determining the types of BPPV exhibited. Therefore, this analysis algorithm will provide assistive information for diagnosis of BPPV to clinicians.
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Development of An Algorithm for Slippage-Induced Motion Artifacts Reduction in Video-Nystagmography Yerin Lee, Young Joon Seo, Sejung Yang Research in Vestibular Science.2022; 21(4): 104. CrossRef
Paraneoplastic cerebellar degeneration is a rare neurological manifestation of nonmetastatic malignancy. Its usual manifestation is subacute to chronic dizziness, gait ataxia, and dysarthria. There have been only a few cases of paraneoplastic cerebellar degeneration with acute presentation. This study describes a patient with paraneoplastic cerebellar degeneration, who presented acute vestibular syndrome and then episodically developed horizontal gaze-evoked nystagmus and gait ataxia.
Dissociated vertical-torsional nystagmus is a unique form of nystagmus characterized by conjugate torsional but disparate vertical components. It has been mainly reported in internuclear ophthalmoplegia or medial medullary lesion involving the medial longitudinal fasciculus (MLF). The patterns of the nystagmus may be explained by a disruption of vestibulo-ocular reflex pathways from vertical semicircular canal or utriculo-ocular reflex within the MLF, but it is debatable. We described a dissociated upbeat-torsional nystagmus in a patient with vestibular nucleus infarction without involvement of MLF.
Vestibular migraine and Menière’s disease have similar clinical features which are recurrent dizziness or auditory symptoms, so it is challengeable to establish the correct diagnosis. Herein, a 31-year-old male and a 56-year-old female showed recurrent dizziness with auditory symptoms and suffered from vestibular migraine. They met the diagnostic criteria for vestibular migraine, but the Menière’s diagnostic criteria were not satisfied as there was no hearing loss. Delayed intravenous gadolinium enhanced magnetic resonance imaging of the inner ear was taken to find out of correlation of the inner ear and revealed endolymphatic hydrops. This case can improve the understanding of the pathophysiology of a vestibular migraine associated Menière’s disease.
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Functional and Molecular Markers for Hearing Loss and Vertigo Attacks in Meniere’s Disease Chao-Hui Yang, Ming-Yu Yang, Chung-Feng Hwang, Kuang-Hsu Lien International Journal of Molecular Sciences.2023; 24(3): 2504. CrossRef
The flocculus plays a crucial role in control of eye movements. Based on animal experiment, it is suggested that the flocculus is important for governing vestibuleocular reflexes. In humans, an isolated floccular lesion is extremely rare. We report oculomotor abnormalities in a patient with unilateral infarction of the flocculus, and compare our results with those of previously reported patients with floccular lesion.
Objectives During caloric irritation, the spinning/rotating sensation is predominant. However, there is no report on the temporal relationship between caloric nystagmus and perception.
Methods Consecutive 57 participants underwent bithermal caloric test in the dizziness clinic of Chungnam National University Hospital from February 2018 to September 2018. For vestibular perception, we asked the subject to report feelings of rotation and/or linear sensation during each warm and cold water irrigation period. Besides routine caloric parameters, the duration of nystagmus and vestibular sensation were analyzed.
Results In most participants, the caloric nystagmus preceded the vestibular sensation (79.6% in right warm, 83.3% in left warm, 88.5% in right cool, and 84.6% in left cool stimuli). The precedence of perception was observed in 5 normal persons and 15 patients with vestibular migraine (n=4), unilateral vestibulopathy (n=3), and Menière’s disease (n=2), multiple systemic atrophy (n=2), cerebellar ataxia (n=2), vertebrobasilar insufficiency (n=1), and post-earthquake dizziness (n=1). The mean latency between nystagmus and perception was 11.7 seconds. And the duration of nystagmus was longer than that of perception in all conditions. Non-spinning sensations during the caloric test were also observed in some participants (26.8% in right warm, 30.3% in left warm, 29.1% in right cool, and 24.1% in left cool stimuli).
Conclusions During the bithemal alternate caloric test, various vestibular perception and temporal relationship between perception and nystagmus suggest the bithermal caloric stimulation does not reflect only the signal originating from the horizontal canal pathway. A further validation study is needed.
Vestibular schwannoma (VS) is commonly encountered in the cerebellopontine angle and benign neoplasms that arise from Schwann cells of the eighth cranial nerve, which can show not only hearing loss but also various vestibular symptoms. Dizziness is the symptom causing significantly negative effect on quality of life in patients with VS. Here, we will review the dizziness in VS.
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Impairment of Vestibular Function in Patients with Vestibular Schwannoma According to the Presence of Dizziness Youngjeong Lee, Se A Lee, Eek-Sung Lee, Tae-Kyeong Lee, Jong Dae Lee Research in Vestibular Science.2022; 21(3): 75. CrossRef
The velocity-storage circuit comprised of bilateral vestibular nucleus complexes, commissural fiber, and nodulus and uvula functions in refining the raw vestibular signal to estimate rotational velocity, gravity direction, and inertia. In this review, we pursued the functional significance of this velocity-storage circuit and how this physiologic knowledge could help us understand the clinical symptoms and signs of patients with vestibular disorders.
Central vertigo is the common symptom resulting from abnormalities in the central nervous system, caused by various diseases, which include neurodegenerative, vascular, inflammation, infection, tumor, paraneoplastic, toxic, or metabolic disorders. Since the treatment of central vertigo depends on the causes, an accurate diagnosis should be preceded the treatment through a detailed neurotologic examination and laboratory evaluation. Also, it is important to identify and document the neurologic findings accompanied by central vertigo, because some medication focuses on the ocular motor abnormalities as nystagmus or saccadic intrusion. Here, we will review the medical treatment for central vertigo.
Sarcoidosis is a rare, multisystem granulomatous disease. Neurological complications occur in about 5% of patients and vestibulocochlear involvement is even rarer. A 27-year-old woman presented with acute spontaneous vertigo for 5 days. She was diagnosed with pulmonary sarcoidosis 4 months ago, but specific treatments have not yet started. She had preceding otologic symptoms including bilateral tinnitus and ear fullness in the right for 3 months without hearing loss. Initial bedside examinations revealed spontaneous right-beating nystagmus and abnormal catch-up saccades in the left during head impulse tests (HIT). After 2 weeks, video-oculography documented the direction of spontaneous nystagmus was changed into left-beating. Caloric test showed canal paresis in the left, and video HIT showed subtle covert saccades. After starting oral prednisolone, her symptoms improved rapidly. In our case, acute vestibular syndrome and otologic symptoms might be associated with sarcoidosis when considering clinical course and treatment response. Sarcoidosis may be considered as a cause in cases with audiovestibulopathy of unknown etiology.
The wide availability of next-generation sequencing has enabled a rapid progress in the discovery of genetic variants associated with many disorders. However, the contribution of genetic factors in vestibular disorders is largely unknown due to the low prevalence of familial disorders and the clinical diversity. A detailed clinical characterization of patients and a choice of proper genetic tests are required to identify the genetic contribution in vestibular disorders. In this review, we will introduce a genetic approach for vestibular disorders and update the evidences to support the genetic contribution in vestibular disorders.
Vast majority of triggering factors preceding vestibular neuritis (VN) are unknown, although many cases are associated with viral infection. A 55-year-old woman was bitten by a viper on her right hand, and she was treated with antivenom at the primary clinic. Three days later, acute persistent vertigo was developed. Neuro-otologic examinations revealed spontaneous left-beating nystagmus and abnormal head impulse test in the right side. Taken together with negative result of brain magnetic resonance imaging, she was diagnosed with a right VN. Various neurological complications such as paralysis, optic neuritis, and stroke can occur after snakebite envenoming. In this case, given the time interval between snakebite and development of dizziness, snakebite envenoming might be a possible predisposing factor of VN as a proinflammatory condition rather than a direct cause of VN. Furthermore, the VN of this case was probably caused by late adverse reactions after antivenom administration. Since about 10% of the snake-bitten patients have complained dizziness, detailed neuro-otologic evaluations may lead to a proper understanding of pathomechanism and a correct diagnosis.
Objectives To survey the satisfaction of customized vestibular exercise using virtual reality system with mobile head-mounted display (HMD) in the elderly patients with chronic unilateral vestibulopathy, we analyzed questionnaires before and after exercise.
Methods Sixteen patients (male, 6; median age, 69 years [interquartile range, 65–75 years]) with chronic unilateral vestibulopathy were prospectively enrolled from March 1 to December 31 in 2018. They exercised once a week for 20 to 25 minutes for 4 weeks using the HMD inserted the virtual reality exercise program. Dizziness visual analogue scale (DAS), Korean vestibular disorders activities of daily living scale (ADL), and visual vertigo analogue scale (VVAS) were performed before and after the exercise. After all of the program, the patients were surveyed to measure the satisfaction for the tool and effect of exercise.
Results DAS, ADL, and VVAS were significantly improved after the vestibular exercise. No one answered unsatisfactory, and at least 62.5% of the patients satisfied the used tool and exercise program. The patients of 50% answered that they satisfied or very satisfied to the efficacy of exercise program. The patients who recovered VVAS more after the exercise were more satisfied to our tools and efficacy of exercise program.
Conclusions Customized vestibular exercise using virtual reality system with HMD can not only improve dizziness and quality of life, but also made more satisfied to the elderly patients with chronic unilateral vestibulopathy.
Objectives Vertigo is a common condition. Definitive treatment is to induce vestibular compensation. Currently, no medications have been discovered that enhance vestibular functional restoration. The current study was conducted to evaluate the ability of ordinary Korean red ginseng (KRG) to induce vestibular compensation.
Methods Twelve Sprague-Dawley rats were divided into two groups. Five rats (KRG group) were fed KRG extract (100 mg/kg) for 2 weeks before undergoing unilateral labyrinthectomy (ULx). The remaining seven rats (control group) were untreated before ULx. After surgery, all animals were housed in the same environment without being fed additional extract. To evaluate vestibular function, gain of the horizontal nystagmus to 0.2 Hz with a peak velocity of 100°/second sinusoidal rotation was compared and analyzed before ULx as well as 3 and 7 days after surgery.
Results Before the operation, gain of the control and KRG group were 0.81±0.05 and 0.88±0.08, respectively, with 0.2-Hz stimulation. This value decreased to 0.43±0.08 and 0.53±0.08, respectively on 3 days after operation (p=0.047), and it was 0.40±0.06 and 0.68±0.11, respectively on 7 days after surgery. The difference of gain between the two groups was statistically significant at each 3 and 7 days (p<0.05). By confirming c-Fos protein expression in medial vestibular nuclei, the functional effect of KRG causing vestibular modulation was confirmed.
Conclusions Rats treated with KRG showed more rapid and complete recovery after acute vestibular loss compared to untreated animals. Therefore, KRG could be one of candidate for the useful medication of vestibular diseases.
Objectives The aim of this paper was to determine if a correlation exists between video head impulse test (vHIT) and electronystagmography with caloric test (ENG). More specifically, comparison of covert and overt value from vHIT test with cold and warm stimulation value from ENG test.
Methods Retrospective study of our single institue from the period of January 2015 to January 2017 enrolled 91 patients. Patients were divided into 3 groups by their diagnosis of either vestibular neuritis (VN), Meniere disease, or sudden sensorineural loss with vertigo accordingly. Each of the patients’ both ENG and vHIT data were recorded and parameters were evaluated.
Results VN group was the only group to show a significant correlation between canal paresis (CP) with covert and overt saccades. Further analysis was done in the VN group and result showed covert saccade showing a larger area under the receiver operation characteristic curve value (0.77) compared to overt saccades (0.70), implying that covert saccade is a more accurate parameter for the prediction of the CP value. Furthermore, a positive correlation was seen between the gain value and the cold caloric stimulation value as well as between warm caloric stimulation value.
Conclusions The value of our study lies in the fact that we have attempted to find a correlation between different parameters of 2 different vestibular tests. We concluded that the evaluation of overt nystagmus by the bedside head thrust test is inappropriate for predicting CP, and a vHIT is required to accurately evaluate vestibular function.
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A Comparative Analysis of the Vestibulocochlear Function in Patients with Isolated Semicircular Canal Hypofunction Using a Video Head Impulse Test Yu Jung Park, Min Young Lee, Ji Eun Choi, Jae Yun Jung, Jung Hwa Bahng Research in Vestibular Science.2023; 22(2): 34. CrossRef
Objectives The aim of the study was to evaluate the possible alteration of the vestibulo-ocular reflex (VOR) in patients with horizontal canal benign paroxysmal positional vertigo (h-BPPV) using the video head impulse test (vHIT).
Methods This was a prospective case-control study of BPPV patients. We includeed 133 patients with h-BPPV who underwent the vHIT prior to the positioning test. The control group consisted of 76 normal subjects who also underwent the vHIT. The vHIT parameters of gain and asymmetry were assessed, and clinical parameters such as treatment duration, number of canalith reposition maneuvers executed and recurrence rates were evaluated. The VOR and clinical parameters were compared between the h-BPPV and control group. The VOR parameters of h-BPPV canalolithiasis were also compared with those of cupulolithiasis.
Results The mean age of the patients was 56.5 years and the male to female ratio was 1:2.02. Of the patients, 75 were diagnosed as having the canalolithiasis type of h-BPPV, while the other 58 had the cupulolithiasis type. The mean vHIT gains of the ipsi-lesional horizontal canal plane were 1.13 and 1.15 in the h-BPPV and control group, respectively (p=0.564). However, the asymmetry of the VOR was significantly higher in the h-BPPV than the control group (p=0.013), while the gains and asymmetries of the vHIT in the canalolith and cupulolith types were not significantly different (p=0.454, p=0.826).
Conclusions The asymmetry of VOR is significantly elevated in the cupulolith type of hBPPV.
Persistent postural perceptual dizziness (PPPD) is a chronic functional vestibular disorder that manifests with 3 or more months of dizziness, nonspinning vertigo, and unsteadiness. These main symptoms are exacerbated by upright posture, active or passive self-motion, and exposure to visual stimuli. PPPD is usually precipitated by illnesses that cause vertigo, dizziness, or unsteadiness. The common precipitants are acute or episodic peripheral vestibular diseases including vestibular neuritis, Meniere disease, or benign paroxysmal positional vertigo. PPPD is not a diagnosis of exclusion. An abnormal finding on examination or laboratory testing does not necessarily exclude a diagnosis of PPPD. This article reviewed the Bárány Society’s diagnostic criteria for PPPD in detail and discussed directions of future investigations.
Ramsay Hunt syndrome is an acquired paralysis of the face specifically caused by a varicella-zoster virus infection in the facial nerve. Other cranial nerves including vestibulo-cochlear disturbance can be affected. Herein we reported a case of Ramsay Hunt syndrome with atypical vestibular syndrome. Although central vestibular signs including direction changing post head-shaking nystagmus or normal head impulse test are generally meaningful, clinicians need to be careful to interpret them because some findings can be observed not only in cases of central disorders but also in peripheral disorders. Clinical findings such as distinct ear pain and close observation of vesicles are important to diagnose Ramsay Hunt syndrome.
Due to the adaptation to environments on Earth, various health-related issues are raised when exposed to different circumstances in space. Of environmental factors in space, gravity alteration has been considered as one of critical environmental changes. The primary inner organ to detect the gravity change is the vestibular system, especially otolith organs, and some limited researches have conducted to understand its mechanical and physiological properties. However, the related consequences were not consistent in despite of well description in systemic effects ranged from the peripheral vestibular system to the central nervous system. Here, we revisited the neuronal and behavioral effects of the gravity alteration on the relevant organs through this review. By representing previous studies for the gravity effects on the peripheral and central vestibular system, this review would provide the concrete understanding of the vestibular responses to the gravity alteration. Also, the physiological responses are expected to provide the useful resources to understand the systemic vestibular responses under the gravity alteration.
Objectives The head impulse test paradigm (HIMP) assesses semicircular canal function by measuring compensatory saccades during head movements as an indication of an impaired vestibulo-ocular reflex (VOR). The recently introduced suppression head impulse test paradigm (SHIMP) examines anticompensatory saccades after head movements as a measure of intact VOR. Thus, HIMP measures a decrease in vestibular function, whereas SHIMP measures residual function. We evaluated the effectiveness of SHIMP, compared HIMP and SHIMP results in the same subjects, and examined the relationship between the 2 tests.
Methods HIMP and SHIMP protocols were performed in 73 patients. The patients were instructed to maintain their gaze on a fixed target for the HIMP, or a moving target for the SHIMP during head impulses. The VOR gain and saccade parameters were compared.
Results HIMP and SHIMP data were obtained for all ears except in 3 patients. The VOR gain with SHIMP was smaller than for HIMP, but showed significant correlation (r=0.8356, p<0.001) and substantial agreement (k=0.79). However, neither the percentage of saccades (appearance of HIMP compensatory saccades and reduction of SHIMP anticompensatory saccades) nor their amplitudes were correlated between the 2 tests.
Conclusions The HIMP and SHIMP protocols are valuable tools to evaluate VOR during high-velocity head movements. Our results confirm their agreement as measures of VOR gain during head impulses, but also show that the relationship between compensatory and anticompensatory saccades is not straightforward. Thus, care should be taken during clinical interpretation of either protocol.
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Normalization of the Suppression Head Impulse Test (SHIMP) and its correlation with the Head Impulse Test (HIMP) in healthy adults Suheda Baran, Gulce Kirazli, Pelin Pistav Akmese, Nese Celebisoy, Tayfun Kirazli Journal of Vestibular Research.2024; 34(1): 15. CrossRef
Test-retest reliability of suppression head impulse paradigm (SHIMP) in healthy individuals Aishwarya Nagarajan, Shashish Ghimire, Varsha Sam Elizabeth, Sujeet Kumar Sinha Hearing, Balance and Communication.2023; 21(4): 312. CrossRef
A nystagmus extraction system using artificial intelligence for video-nystagmography Yerin Lee, Sena Lee, Junghun Han, Young Joon Seo, Sejung Yang Scientific Reports.2023;[Epub] CrossRef
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Development of An Algorithm for Slippage-Induced Motion Artifacts Reduction in Video-Nystagmography Yerin Lee, Young Joon Seo, Sejung Yang Research in Vestibular Science.2022; 21(4): 104. CrossRef
VOR gain of lateral semicircular canal using video head impulse test in acute unilateral vestibular hypofunction: A systematic review Mohamad Alfarghal, Mohammed Abdullah Algarni, Sujeet Kumar Sinha, Aishwarya Nagarajan Frontiers in Neurology.2022;[Epub] CrossRef
Evaluation of high frequency horizontal VOR parameters in patients with chronic bilateral and unilateral peripheral vestibulopathy: a preliminary study Gulce Kirazli, Sevinc Hepkarsi, Tayfun Kirazli Acta Oto-Laryngologica.2020; 140(12): 1007. CrossRef
A 25-year-old woman presented with atypical dizziness with oscillopsia. The neuro-otological evaluations showed bilateral vestibulopathy with mild sensorineural hearing loss. Computed tomography and magnetic resonance imaging demonstrated bilateral isolated lateral canal dysplasia (LSCD) with normal cochlea. LSCD is relatively common inner ear malformation, but it is rarely found in bilateral vestibulopathy. In case of patients with bilateral vestibulopathy who cannot find the cause, should be considered conducting radiological examinations in mind of the inner ear anomalies.
Objectives Bilateral vestibulopathy is characterized with unsteadiness and oscillopsia when walking or standing, worsening in darkness and/or on uneven ground. To establish the effect of customized vestibular rehabilitation in bilateral vestibulopathy, we analyzed the questionnaires and functional status before and after treatment.
Methods Among 53 patients with customized vestibular rehabilitation from January 1st to November 30th in 2018, 6 patients (3 males; median age, 71 years; range, 54–75 years) who regularly exercised with good compliance were retrospectively enrolled. They were educated and trained the customized vestibular rehabilitation once a month or two by a supervisor during 40 minutes, and then exercised at home for 30 minutes over 5 days in a week. Dizziness handicap inventory (DHI), Korean vestibular disorders activities of daily living scale (vADL), Beck’s depression index (BDI), test for dynamic visual acuity (DVA), and Timed Up and Go test (TUG) were performed before and after the customized vestibular rehabilitation.
Results The patients exercised for median 5.5 months (range, 2–10 months) with the customized methods of vestibular rehabilitation, which included gaze and posture stabilization and gait control exercises. DHI score and TUG was improved after rehabilitation (DHI before vs. after rehabilitation=33 vs. 16, p=0.027, TUG before vs. after rehabilitation=12 vs. 10, p=0.026). BDI, DVA, and vADL scores did not differ between before and after treatment.
Conclusions Customized vestibular rehabilitation can improve dizziness and balance state in bilateral vestibulopathy. The steady exercises adapted individual peculiarities is the most important for vestibular rehabilitation.
Objectives Despite patients with dizziness were reported of revealing gait problems, there is still lack of objective quantitative measurement of gait patterns of peripheral vestibular disorders. To demonstrate gait variability in acute unilateral peripheral vestibular deficit, we evaluated the differences in gait patterns between vestibular neuritis (VN) patients and healthy subjects by the use of shoe-type inertial measurement unit (IMU) with sensors mounted.
Methods Between April 2017 and January 2019, 30 patients diagnosed with unilateral peripheral vestibular deficit presumed to be caused by VN were enrolled in this study. The shoe-type IMU was used to analysis subjects. We assessed gait speed, cadence, stride length, stance phase, normalized stride length, normalized step length, phase coordination index and gait asymmetry of data from shoe-type IMU sensors with the walking protocol. We tested 30 healthy volunteers as control group.
Results We identified spatiotemporal parameters of human gait. The gait speed of patients with VN was decreased to 3.82±0.8 compared to 4.93±1.08 in control group. In addition, there were differences in normalized stride length, normalized gait speed and related gait parameters, when comparing VN group and control group.
Conclusion Gait analysis by the use of shoe-type IMU could provide important information regarding vestibular pathophysiology in patients with VN. Gait performance tests can examine gait variability quantitatively. It will be taken into consideration as a vestibular function test for patients with vertigo.
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Comparison of Gait Parameters during Forward Walking under Different Visual Conditions Using Inertial Motion Sensors Eun Jin Son, Ji Hyung Kim, Hye Eun Noh, Inon Kim, Joo Ae Lim, Seung Hwan Han Yonsei Medical Journal.2022; 63(1): 82. CrossRef
Objectives The purpose of this study is to investigate characteristics of nystagmus during attacks of vestibular migraine (VM), and to find a distinct clinical feature compared to other migraine and peripheral vestibular disorders.
Methods This study is a retrospective chart review of 82 patients satisfied with VM criteria, which is formulated by the new Bárány Society. Spontaneous and positional nystagmus provoked by various head positions were examined with video-nystagmography in all patients. Bithermal caloric test and cervical vestibular evoked myogenic potential test (cVEMP) were also performed. The direction and peak slow-phase velocity (SPV) of nystagmus, unilateral caloric weakness and interaural difference of cVEMP were analyzed. Control groups were lesion side in acute VN for nystagmus results and healthy side in the patients with benign paroxysmal positional vertigo of posterior semicircular canal for caloric and cVEMP results. Chi-square test and Mann-Whitney U-test were used for statistical analysis.
Results During the acute attack, nystagmus was seen in 71.9% (59 of 82) of patients. Horizontal nystagmus was the predominant type. Peak SPV in VM patients was much slower than in the control group (2.37±1.73 °/sec vs. 17.05±12.69 °/sec, p<0.0001). There was no significant difference on the result of both caloric and cVEMP test, compared to those of control groups.
Conclusion Nystagmus with horizontal directions and low SPV was dominant form in the attack of VM. Close observation of nystagmus can be helpful to make a correct diagnosis and to understand the pathomechanism of vertigo in VM.
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Vestibular Migraine: A Recent Update on Diagnosis and Treatment Young Seo Kim, Hak Seung Lee Research in Vestibular Science.2022; 21(3): 67. CrossRef
The vestibular symptoms such as dizziness and imbalance that occurred after traumatic head/brain injury were caused by a combination of central factors such as abnormalities of white matter, diffuse axonal injury and microhemorrhage, and peripheral factors like decreased vestibulo-ocular reflex caused by the energy transmitted to the semicircular canal and otolith organs. These symptoms can affect on the patient's overall physical, cognitive, emotional, and quality of life. There have been reports that vestibular rehabilitation for the treatment of dizziness and imbalance after head trauma can promote vestibular compensation, stabilize of the gaze movements, and also affect the treatment outcomes of the associated injuries. The frequency, duration, and number of people participating in vestibular rehabilitation varied with each study, and physical therapy, occupational therapy, cognitive counseling, medication treatment, duration of treatment for associated injuries were also variable. Most studies have shown that many patients who get the vestibular rehabilitation have a significantly reduced time to return to work and sports activities, and may be able to speed up the recovery of vestibular symptoms. However, further research is needed on its long-term effects. In addition, patients with traumatic head/brain injuries are more susceptible to injuries of other organs as well as vestibular disorders, therefore consideration of treatment planning for associated injuries including precise evaluation mental support, and cognitive therapy is expected to be more effective with vestibular rehabilitation therapy.
Traumatic brain injury (TBI) could give rise to variable clinical manifestations based on the involved structures of our bodies. Although there are no structural abnormalities proven, the patients with mild TBI suffer from chronic dizziness and imbalance. Herein, I will discuss the visuo-vestibular interaction and neurotological finding in TBI, which could demonstrate the clue to the diagnosis and management in dizzy patients with TBI.
Objectives Suppression head impulse paradigm (SHIMP) in video head impulse test is now newly used to test vestibular function. The aim of this study was to analyze normative values of SHIMP for healthy Korean subjects in each decade of life.
Methods SHIMP and HIMP responses were measured with the video head impulse test in 70 healthy subjects. Vestibulo-ocular reflex gain and anticompensatory saccade were analyzed and compared at each decade of life.
Results All subjects produced anticompensatory saccades in SHIMP. Gain values did not vary significantly with age. Gain values in SHIMP were lower than gain values in HIMP. The gain values of rightward impulse were higher than the gain values of leftward impulse.
Conclusions Gain values and anticompensatory saccades in SHIMP were consistently equal in each decade of life. Normative values of SHIMP seems largely unaffected by aging.
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Normalization of the Suppression Head Impulse Test (SHIMP) and its correlation with the Head Impulse Test (HIMP) in healthy adults Suheda Baran, Gulce Kirazli, Pelin Pistav Akmese, Nese Celebisoy, Tayfun Kirazli Journal of Vestibular Research.2024; : 1. CrossRef
Acute vestibular neuritis (VN) is characterized by acute/subacute vertigo with spontaneous nystagmus and unilateral loss of semicircular canal function. Vestibular system in human is represented in the brain bilaterally with functional asymmetries of the right hemispheric dominance in the right handers. Spatial working memory entails the ability to keep spatial information active in working memory over a short period of time which is also known as the right hemispheric dominance. Three patients (patient 1, 32-year-old female; patient 2, 18-year-old male; patient 3, 63-year-old male) suffered from acute onset of severe vertigo, nausea and vomiting. Patients 1 and 2’s examination revealed VN on the right side showing spontaneous left beating nystagmus and impaired vestibular ocular reflex on the right side in video head-impulse and caloric tests. Patient 3’s finding was fit for VN on the left side. We also evaluated visuospatial memory function with the block design test in these 3 VN patients which discovered lower scores in patients 1 and 2 and the average level in patient 3 compare to those of healthy controls. Follow-up block design test after resolved symptoms showed within normal range in both patients. Our cases suggest that the patients with unilateral peripheral vestibulopathy may have an asymmetrical effect on the higher vestibular cognitive function. The right VN can be associated with transient visuospatial memory dysfunction. These findings add the evidence of significant right hemispheric dominance for vestibular and visuospatial structures in the right-handed subjects, and of predominant dysfunction in the hemisphere ipsilateral to the peripheral lesion side.
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The Differential Effects of Acute Right- vs. Left-Sided Vestibular Deafferentation on Spatial Cognition in Unilateral Labyrinthectomized Mice Thanh Tin Nguyen, Gi-Sung Nam, Jin-Ju Kang, Gyu Cheol Han, Ji-Soo Kim, Marianne Dieterich, Sun-Young Oh Frontiers in Neurology.2021;[Epub] CrossRef
Objectives Over the last decades, numerous studies on the effect of vestibular rehabilitation (VR) have been reported in western countries, but there has been no report about real experiences of customized VR in Korea. The aim of this study was to analyze of the efficacy, compliance and satisfaction in patients with acute and chronic dizziness.
Methods Patients with dizziness were treated with a customized VR at least 4 weeks. Subjects were assessed before and after at least 4 weeks of customized VR for visual analogue scale (VAS) and disability scale (DS). Patients were asked to score the satisfaction of their treatment as 1 (very poor) to 5 (excellent). Compliance to exercise program were graded as 1 (regularly performed), 2 (frequently performed), or 3 (rarely performed).
Results Thirty-two patients with dizziness were included. Diagnosis of patients were vestibular migraine (n=5), Meniere’s disease (n=2), vestibular neuritis (n=10), persistent perceptual positional dizziness (n=10), bilateral vestibulopathy (n=3), and central dizziness (n=2). Mean VAS and DS before VR were 15.3 and 2.4, respectively. Mean VAS and DS after VR were 4.5 and 0.7, respectively. Significant improvements in VAS and DS were observed after VR (p=0.00). Mean treatment satisfaction score was 3.3±1.0 and mean compliance score was 2.3±0.8. Satisfaction to VR showed positive correlation with patient’s compliance. (p=0.00, r=0.644)
Conclusions Significant improvements were seen in symptom and disability in patients with acute and chronic dizziness after customized VR. Patients showed moderate compliance to exercise program and overall satisfaction was fair.
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A Survey of Educational, Clinical Background in Vestibular Rehabilitation Therapy of Korean Physical Therapists Migyoung Kweon, Youn Bum Sung The Journal of Korean Academy of Physical Therapy .2023; 30(2): 65. CrossRef
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Objectives This study was conducted to assess the current management status of the vestibular function test laboratories in Korea.
Methods Questionnaire about the management status of the vestibular function test laboratories was sent by email to the entire members of the Korean Balance Society. The contents of questionnaire included situation of employees who perform the tests, the types of vestibular function tests and equipment, frequency of the test and types of dizziness related questionnaires.
Results Forty-nine hospitals and clinics responded. All the 49 respondents answered that they have videonystagmography. Spontaneous nystagmus analysis by videonystagmogrphy was the most frequently tests for patients with dizziness. Questionnaires for dizziness were used by 27 respondents (55.1%) for initial evaluation of the dizziness patients. The Korean version of dizziness handicap inventory was the most frequently used dizziness related questionnaire. Conclusions: We analyzed the current management status of vestibular function test laboratories to comprehend the present condition of the vestibular function test. We think that these results will help to provide a standard for laboratory operations and prepare for the education, focusing on high-demand tests.
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The impact examination of the head tilt size on the subjective visual vertical (SVV) among the normal individuals with ages ranged from 18 to 35 years Mahmoud Rezvani Amin, Hadi Behzad Hearing, Balance and Communication.2022; 20(2): 129. CrossRef
Objectives Excitability o medial vestibular nucleus (MVN) in the brainstem can be affected by changes in the arterial blood pressure. Several animal studies have demonstrated that acute hypotension results in the alteration of multiunit activities and expression of cFos protein in the MVN. In the field of extracellular electrophysiological recording, tetrode technology and spike sorting algorithms can easily identify single unit activity from multiunit activities in the brain. However, detailed properties of electrophysiological changes in single unit of the MVN during acute hypotension have been unknown.
Methods Therefore, we applied tetrode techniques and electrophysiological characterization methods to know the effect of acute hypotension on single unit activities of the MVN of rats.
Results Twoor3typesofunitcouldbeclassifiedaccordingtothemorphologyofspikes and firing properties of neurons. Acute hypotension elicited 4 types of changes in spontaneous firing of single unit in the MVN. Most of these neurons showed excitatory responses for about within 1 minute after the induction of acute hypotension and then returned to the baseline activity 10 minutes after the injection of sodium nitroprusside. There was also gradual increase in spontaneous firing in some units. In contrast small proportion of units showed rapid reduction of firing rate just after acute hypotension. Conclusions: Therefore, application of tetrode technology and spike sorting algorithms is another method for the monitoring of electrical activity of vestibular nuclear during acute hypotension.
Objectives We aimed to study the role of vestibular input on spatial memory performance in mice that had undergone bilateral surgical labyrinthectomy, semicircular canal (SCC) occlusion and 4G hypergravity exposure.
Methods Twelve to 16 weeks old ICR mice (n=30) were used for the experiment. The experimental group divided into 3 groups. One group had undergone bilateral chemical labyrinthectomy, and the other group had performed SCC occlusion surgery, and the last group was exposed to 4G hypergravity for 2 weeks. The movement of mice was recorded using camera in Y maze which had 3 radial arms (35 cm long, 7 cm high, 10 cm wide). We counted the number of visiting arms and analyzed the information of arm selection using program we developed before and after procedure.
Results The bilateral labyrinthectomy group which semicircular canal and otolithic function was impaired showed low behavioral performance and spacial memory. The semicircular canal occlusion with CO2 laser group which only semicircular canal function was impaired showed no difference in performance activity and spatial memory. However the hypergravity exposure group in which only otolithic function impaired showed spatial memory function was affected but the behavioral performance was spared. The impairment of spatial memory recovered after a few days after exposure in hypergravity group.
Conclusions This spatial memory function was affected by bilateral vestibular loss. Space-related information processing seems to be determined by otolithic organ information rather than semicircular canals. Due to otolithic function impairment, spatial learning was impaired after exposure to gravity changes in animals and this impaired performance was compensated after normal gravity exposure.
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Galvanic Vestibular Stimulation Improves Spatial Cognition After Unilateral Labyrinthectomy in Mice Thanh Tin Nguyen, Gi-Sung Nam, Jin-Ju Kang, Gyu Cheol Han, Ji-Soo Kim, Marianne Dieterich, Sun-Young Oh Frontiers in Neurology.2021;[Epub] CrossRef
The Differential Effects of Acute Right- vs. Left-Sided Vestibular Deafferentation on Spatial Cognition in Unilateral Labyrinthectomized Mice Thanh Tin Nguyen, Gi-Sung Nam, Jin-Ju Kang, Gyu Cheol Han, Ji-Soo Kim, Marianne Dieterich, Sun-Young Oh Frontiers in Neurology.2021;[Epub] CrossRef
There are a number of reports on the pathologies of vestibular disorders. However, these studies included only a few examples, which were not quantitative but merely anecdotal or descriptive. However, a single tissue section may be relevant to a specific disease in multiple ways. The histopathological characteristics of common peripheral vestibulopathies, including benign paroxysmal positional vertigo, Ménière’s syndrome, labyrinthitis, vestibular neuritis, and ototoxicity, have been described. A recent study validated a new quantitative method for determining vestibular otopathology. Detailed quantitative analyses of vestibular pathology are required to obtain a deeper understanding of the vestibular system. Such studies will likely reveal the pathophysiological causes of specific diseases by elucidating the correlations between structural and functional features. Therefore, histopathological studies of vestibular disorders should be performed.
Posttraumatic vertigo can be defined as the vertiginous disorder occurred after head and neck trauma without other pre-existing vestibular disorder. Central, peripheral, and combined deficits might cause this condition. Especially, various peripheral vestibulopathies are possible causes of posttraumatic vertigo; benign paroxysmal positional vertigo, temporal bone fracture, perilymphatic fistula, labyrinthine concussion, posttraumatic hydrops, and cervical vertigo. Since the differential diagnosis of the posttraumatic vertigo is often difficult, it is essential to acquire knowledge of their pathophysiology and clinical features. In this review, peripheral vestibulopathy as the possible causes of posttraumatic vertigo were described according to the current literature.
Objectives Vertigo combined with sudden sensorineural hearing loss (SSNHL) is known as a poor prognostic factor. We investigated clinical findings and vestibular function tests in patients of SSNHL with vertigo to find the prognostic factors.
Methods We retrospectively evaluated data on the patients diagnosed with SSNHL with vertigo at Bucheon Soonchunhyang University Hospital from March 2009 to February 2018. We reviewed medical records and the results of vestibular function tests and audiometry.
Results Of the 68 patients, 30 (44.1%) showed profound hearing loss and 53 (77.9%) showed poor recovery. Age and the degree of initial hearing loss showed negative prognostic factor in hearing recovery. Abnormal results of cervical vestibular evoked myogenic potentials (cVEMP) also showed significantly differences between good and poor recovery groups.
Conclusions In this study, most of the patients of SSNHL with vertigo showed poor recovery. Age, degree of initial hearing loss, and the abnormal result of the cVEMP have a negative effect on the prognosis of hearing recovery.