scholarly journals Ocular Vestibular Evoked Myogenic Potentials and Intravestibular Intralabyrinthine Schwannomas

2018 ◽  
Vol 97 (7) ◽  
pp. E21-E25 ◽  
Author(s):  
Massimo Ralli ◽  
Giuseppe Nola ◽  
Massimo Fusconi ◽  
Luca Sparvoli ◽  
Giovanni Ralli
Keyword(s):  
Contralateral Side ◽  
Vestibular Evoked Myogenic Potentials ◽  
Diagnostic Process ◽  
Benign Tumors ◽  
Average Delay ◽  
Diagnostic Modality ◽  
Ocular Reflex ◽  
Vestibulo Ocular Reflex ◽  
Magnetic Resonance Imaging Mri ◽  
The Right

Intravestibular intralabyrinthine schwannomas (ILSs) are uncommon benign tumors that arise from the sac-cular, utricular, and lateral and superior ampullary nerves. According to the literature, there is an average delay of 8 years between the onset of symptoms and diagnosis. Te diagnosis is based on an audiovestibular examination and magnetic resonance imaging (MRI). We describe a case of intravestibular ILS in which we included the ocular vestibular evoked myogenic potentials (oVEMPs) test in the diagnostic workup. The oVE-MPs test is a relatively new neurophysiologic diagnostic modality that evaluates the superior vestibular pathway and the ascending contralateral pathway through the vestibulo-ocular reflex. In our case, a 65-year-old man presented with progressive right-sided sensorineu-ral hearing loss, dizziness, and tinnitus and fullness in his right ear. Audiovestibular examination and MRI detected an intravestibular ILS on the right. We found that oVEMPs were absent on the contralateral side, which contributed to the diagnostic process. Te detection of oVEMPs can provide detailed information on the functionality of the macula of the utricle and the lateral and superior ampullary nerves, with a precise identification of the affected area. Based on our findings, we discuss the role of oVEMPs in the diagnosis of an intravestibular ILS.

Effects of cochlear implants on otolith function as evaluated by vestibulo-ocular reflex and vestibular evoked myogenic potentials

2019 ◽  
Vol 46 (6) ◽  
pp. 836-843
Author(s):  
Takao Imai ◽  
Tomoko Okumura ◽  
Yumi Ohta ◽  
Kazuo Oshima ◽  
Takashi Sato ◽  
...  
Keyword(s):  
Cochlear Implants ◽  
Vestibular Evoked Myogenic Potentials ◽  
Ocular Reflex ◽  
Otolith Function ◽  
Vestibulo Ocular Reflex

scholarly journals Simultaneous and opposing horizontal VOR adaptation in humans suggests functionally independent neural circuits

2018 ◽  
Vol 120 (4) ◽  
pp. 1496-1504 ◽  
Author(s):  
Yoav Gimmon ◽  
Americo A. Migliaccio ◽  
Christopher J. Todd ◽  
William V. C. Figtree ◽  
Michael C. Schubert
Keyword(s):  
Head Rotation ◽  
Learning Context ◽  
Training Conditions ◽  
Nonlinear Properties ◽  
Ocular Reflex ◽  
Stable Vision ◽  
Vestibulo Ocular Reflex ◽  
Vor Adaptation ◽  
Vor Training ◽  
The Right

The healthy vestibulo-ocular reflex (VOR) ensures that images remain on the fovea of the retina during head rotation to maintain stable vision. VOR behavior can be measured as a summation of linear and nonlinear properties although it is unknown whether asymmetric VOR adaptation can be performed synchronously in humans. The purpose of the present study is twofold. First, examine whether the right and left VOR gains can be synchronously adapted in opposing directions. Second, to investigate whether the adaptation context transfers between both sides. Three separate VOR adaptation sessions were randomized such that the VOR was adapted Up-bilaterally, Down-bilaterally, or Mixed (one side up, opposite side down). Ten healthy subjects completed the study. Subjects were tested while seated upright, 1 meter in front of a wall in complete dark. Each subject made active (self-generated) head impulse rotations for 15 min while viewing a gradually increasing amount of retinal slip. VOR training demand changed by 10% every 90 s. The VOR changed significantly for all training conditions. No significant differences in the magnitude of VOR gain changes between training conditions were found. The human VOR can be simultaneously driven in opposite directions. The similar magnitude of VOR gain changes across training conditions suggests functionally independent VOR circuits for each side of head rotation that mediate simultaneous and opposing VOR adaptations. NEW & NOTEWORTHY Our results indicate that humans have the adaptive capacity for concurrent and opposing directions of vestibulo-ocular reflex (VOR) motor learning. Context specificity of VOR adaptation is dependent on the error signal being unilateral or bilateral, which we illustrate via a lack of VOR gain transfer using unique adaptive demands.

scholarly journals Intractable Trigeminal Neuralgia Secondary to Osteoma of the Clivus: A Case Report and Literature Review

2022 ◽  
Author(s):  
Ebtesam Abdulla ◽  
Krishna Das ◽  
Joseph Ravindra ◽  
Tejal Shah ◽  
Sara George
Keyword(s):  
Trigeminal Neuralgia ◽  
Pressure Effect ◽  
Benign Tumors ◽  
Radiographic Images ◽  
Patient Reported ◽  
Magnetic Resonance Imaging Mri ◽  
The Right ◽  
Slow Growing ◽  
Serial Observation

AbstractSkull base osteomas (SBOs) are benign tumors that are frequently detected on radiographic images by coincidence. They are known for being slow-growing tumors and rarely symptomatic. The therapeutic approach for SBOs can differ substantially. Depending on the symptoms, size, and location of the tumor, this can range from serial observation to vigorous surgical extirpation. Clival osteoma is extremely rare. We report a case of clival osteoma, causing intractable trigeminal neuralgia due to the pressure effect on the trigeminal nerve at Meckel's cave. We also provide a review of pertinent literature. A 37-year-old woman presented with intractable trigeminal neuralgia. Cranial magnetic resonance imaging (MRI) demonstrated a large, lobulated, extra-axial lesion involving the right cerebellopontine angle and epicentering the clivus. Pathologically, the specimen was proven to be osteoma. The patient reported complete symptom resolution over a 4-year follow-up period. To the best of the authors' knowledge, this is the first clinical case of intractable trigeminal neuralgia due to clival osteoma.

scholarly journals Vestibulo-ocular reflex gain and compensatory saccades in three semicircular canals by video head impulse test

2019 ◽  
Author(s):  
Homa Zarrinkoob ◽  
Hadi Behzad ◽  
Seyed Mehdi Tabatabaee
Keyword(s):  
High Velocity ◽  
Semicircular Canals ◽  
Head Impulse Test ◽  
Video Head Impulse Test ◽  
Low Velocity ◽  
Head Impulse ◽  
Ocular Reflex ◽  
Vestibulo Ocular Reflex ◽  
Reflex Gain ◽  
The Right

Background and Aim: One of the tools for ass­essing the vestibulo-ocular reflex (VOR) is using video head impulse test (vHIT). In this test by placing the head at different angles and shaking the head, three semicircular canals of the vestibular system in each ear can be exami­ned separately. The purpose of this study was to investigate the relationship between the low and high velocities of the vHIT test with VOR and its compensatory saccades. Methods: The vHIT test was performed by an examiner in 49 normal individuals aged 23–39 at low and high velocities. All participants had normal hearing, visual, and vestibular systems. Results: Mean gains in the horizontal, anterior and posterior semicircular canals in the right ear respectively were 0.92, 1 and 0.90 and in the left ear 0.93, 0.99 and 0.95 for low velocity and 0.78, 0.92 and 0.79 in the right ear and 0.80, 0.85 and 0.86 in the left ear for high velocity. Also, the number of compensatory saccade at high velocity was higher than those at the low velocity and the latency of compensatory sacc­ade was lower at the higher velocity. Conclusion: In the vHIT test, VOR gain decreases at high velocity that is statistically significant. Also, compensatory saccades are more likely to occur at high velocity with sma­ller delay. Therefore, high-velocity vHIT test is not recommended for the purpose of examining the VOR gain and compensatory saccade.

Ictal downbeat nystagmus in Ménière disease

Neurology ◽  
2020 ◽  
Vol 95 (17) ◽  
pp. e2409-e2417
Author(s):  
Sun-Uk Lee ◽  
Hyo-Jung Kim ◽  
Jeong-Yoon Choi ◽  
Ji-Soo Kim
Keyword(s):  
Semicircular Canals ◽  
Vestibular Evoked Myogenic Potentials ◽  
Slow Phase ◽  
Downbeat Nystagmus ◽  
Meniere Disease ◽  
Head Impulse ◽  
Slow Phase Velocity ◽  
Ocular Reflex ◽  
Vestibulo Ocular Reflex ◽  
Menière Disease

ObjectiveTo determine the mechanism of ictal downbeat nystagmus in Ménière disease (MD), we compared the head impulse gain of the vestibulo-ocular reflex (VOR) for each semicircular canal between patients with (n = 7) and without (n = 70) downbeat nystagmus during attacks of MD.MethodsWe retrospectively analyzed the results of video-oculography, video head-impulse tests, and cervical vestibular-evoked myogenic potentials (VEMPs) in 77 patients with definite MD who were evaluated during an attack.ResultsPure or predominant downbeat nystagmus was observed in 7 patients (9%) with unilateral MD during the attacks. All 7 patients showed spontaneous downbeat nystagmus without visual fixation with a slow phase velocity ranging from 1.5 to 11.2°/s (median 5.4, interquartile range 3.7–8.5). All showed a transient decrease of the head impulse VOR gains for the posterior canals (PCs) in both ears (n = 4) or in the affected ear (n = 3). Cervical VEMPs were decreased in the affected (n = 2) or both ears (n = 2) when evaluated during the attacks. Downbeat nystagmus disappeared along with normalization of the VOR gains for PCs after the attacks in all patients. During the attacks, the head impulse VOR gains for the PC on the affected side were lower in the patients with ictal downbeat nystagmus than in those without (Mann-Whitney U test, p < 0.001), while the gains for other semicircular canals did not differ between the groups.ConclusionDownbeat nystagmus may be observed during attacks of MD due to an asymmetry in the vertical VOR or saccular dysfunction. MD should be considered in recurrent audiovestibulopathy and ictal downbeat nystagmus.

Impaired vestibular responses in internuclear ophthalmoplegia

Neurology ◽  
2017 ◽  
Vol 89 (24) ◽  
pp. 2476-2480 ◽  
Author(s):  
Seo-Young Choi ◽  
Hyo-Jung Kim ◽  
Ji-Soo Kim
Keyword(s):  
Vestibular Evoked Myogenic Potentials ◽  
Medial Longitudinal Fasciculus ◽  
Subjective Visual Vertical ◽  
Internuclear Ophthalmoplegia ◽  
Horizontal Canal ◽  
Head Impulse ◽  
Ocular Tilt Reaction ◽  
Ocular Reflex ◽  
Vestibulo Ocular Reflex ◽  
Visual Vertical

Objective:To determine the role of the medial longitudinal fasciculus (MLF) in conveying vestibular signals.Methods:In 10 patients with isolated acute unilateral internuclear ophthalmoplegia (INO) due to an acute stroke, we performed comprehensive vestibular evaluation using video-oculography, head impulse tests with a magnetic search coil technique, bithermal caloric tests, tests for the ocular tilt reaction, and measurements of subjective visual vertical and cervical and ocular vestibular evoked myogenic potentials (VEMPs).Results:The head impulse gain of the vestibulo-ocular reflex (VOR) was decreased invariably for the contralesional posterior canal (PC) (n = 9; 90%) and usually for the ipsilesional horizontal canal (n = 5; 50%). At least one component of contraversive ocular tilt reaction (n = 9) or contraversive tilt of the subjective visual vertical (n = 7) were common along with ipsitorsional nystagmus (n = 5). Cervical or ocular VEMPs were abnormal in 5 patients.Conclusions:The MLF serves as the main passage for the high-acceleration VOR from the contralateral PC. The associations and dissociations of the vestibular dysfunction in our patients indicate variable combinations of damage to the vestibular fibers ascending or descending in the MLF even in strokes causing isolated unilateral INO.

scholarly journals Congenital monocular elevation deficiency associated with a novel TUBB3 gene variant

2019 ◽  
Vol 104 (4) ◽  
pp. 547-550 ◽  
Author(s):  
Mervyn G Thomas ◽  
Gail D E Maconachie ◽  
Cris S Constantinescu ◽  
Wai-Man Chan ◽  
Brenda Barry ◽  
...  
Keyword(s):  
Focal Cortical Dysplasia ◽  
Mutation Screening ◽  
Royal Infirmary ◽  
Bilateral Ptosis ◽  
Ocular Reflex ◽  
Vestibulo Ocular Reflex ◽  
Α Helix ◽  
The Right ◽  
Leicester Royal Infirmary ◽  
Older Sibling

BackgroundThe genetic basis of monocular elevation deficiency (MED) is unclear. It has previously been considered to arise due to a supranuclear abnormality.MethodsTwo brothers with MED were referred to Leicester Royal Infirmary, UK from the local opticians. Their father had bilateral ptosis and was unable to elevate both eyes, consistent with the diagnosis of congenital fibrosis of extraocular muscles (CFEOM). Candidate sequencing was performed in all family members.ResultsBoth affected siblings (aged 7 and 12 years) were unable to elevate the right eye. Their father had bilateral ptosis, left esotropia and bilateral limitation of elevation. Chin up head posture was present in the older sibling and the father. Bell’s phenomenon and vertical rotational vestibulo-ocular reflex were absent in the right eye for both children. Mild bilateral facial nerve palsy was present in the older sibling and the father. Both siblings had slight difficulty with tandem gait. MRI revealed hypoplastic oculomotor nerve. Left anterior insular focal cortical dysplasia was seen in the older sibling. Sequencing of TUBB3 revealed a novel heterozygous variant (c.1263G>C, p.E421D) segregating with the phenotype. This residue is in the C-terminal H12 α-helix of β-tubulin and is one of three putative kinesin binding sites.ConclusionWe show that familial MED can arise from a TUBB3 variant and could be considered a limited form of CFEOM. Neurological features such as mild facial palsy and cortical malformations can be present in patients with MED. Thus, in individuals with congenital MED, consideration may be made for TUBB3 mutation screening.

scholarly journals Evaluation of Interexaminer Variability in Video Head Impulse Test Results

2020 ◽  
Vol 31 (08) ◽  
pp. 613-619
Author(s):  
Başak Mutlu ◽  
Sıdıka Cesur ◽  
Merve Torun Topçu ◽  
Cennet Reyyan Geçici ◽  
Öyküm Esra Aşkın ◽  
...  
Keyword(s):  
Repeated Measures ◽  
Semicircular Canals ◽  
Head Impulse Test ◽  
Video Head Impulse Test ◽  
Head Impulse ◽  
Lateral Canal ◽  
Ocular Reflex ◽  
Left Posterior ◽  
Vestibulo Ocular Reflex ◽  
The Right

Abstract Objective The video head impulse test (vHIT) is a diagnostic tool to assess the function of the semicircular canals and branches of the vestibular nerve. The aim of this study was to analyze the interexaminer variability of vHIT results in healthy subjects. Materials and Methods A total of 21 healthy participants were included in the study. vHIT responses were collected by four clinicians. Variability of the vHIT results between examiners was analyzed statistically. Results The vestibulo-ocular reflex (VOR) velocity regression values were from 0.99 to 1.09 degrees per second for the lateral canals. For the vertical canals, VOR velocity regression values were from 0.87 to 1.21 degrees per second. According to repeated measures analysis of variance, the normality assumptions for the velocity regression of the left lateral canal (p = 0.002) and the right anterior canal (p < 0.01) were met and the differences were statistically significant. The normality assumptions were not met for 40, 60, and 80 ms median gain of the right lateral canal (p = 0.016, p = 0.038, and p = 0.001, respectively); 40 and 60 ms median gain of the left lateral canal (p < 0.001 and p = 0.008, respectively); and the velocity regression of the left posterior canal (p < 0.00). These differences were found to be statistically significant by using the Friedman test. Conclusion The interexaminer differences of the VOR gain values for the vHIT were statistically significant. Serial vHIT testing should be performed by the same examiner to reduce the effects of interexaminer variability.

scholarly journals Drop Attack Treated by Microvascular Decompression of the Superior Vestibular Nerve

2021 ◽  
pp. 014556132110436
Author(s):  
Sanghoon Kim ◽  
Soo-Keun Kong ◽  
Jae Meen Lee ◽  
Se-Joon Oh
Keyword(s):  
Microvascular Decompression ◽  
Vestibular Nerve ◽  
Vestibular Evoked Myogenic Potentials ◽  
Anterior Inferior Cerebellar Artery ◽  
Mri Findings ◽  
Vestibulocochlear Nerve ◽  
Drop Attack ◽  
History Of ◽  
Magnetic Resonance Imaging Mri ◽  
The Right

We report a case of cochleovestibular neurovascular compressive syndrome (CVCS)-induced drop attack treated with microvascular decompression (MVD) of the superior vestibular nerve. This report discusses the merits of surgical intervention through a review of related literature. A 58-year-old woman was referred to our clinic with a chief complaint of intermittent, strong, right-sided tinnitus lasting for a few seconds immediately prior to drop attack. Magnetic resonance imaging (MRI) showed bilateral neurovascular contact between the anterior inferior cerebellar artery (AICA) and the vestibulocochlear nerve. Based on MRI findings, history of present illness, and response to anticonvulsants, CVCS was suspected, and surgical decompression on the right side was subsequently performed. The patient became asymptomatic immediately after the surgery, and the vestibular-evoked myogenic potentials were normalized. No recurrence was reported during a 1-year follow-up period.

Sign in / Sign up

Export Citation Format

Share Document