Search Results (61)

Background/Objectives: Skull vibration-induced nystagmus (SVIN) is a robust sign of vestibular asymmetry, yet its relationship with tests of impulsive canal function, short-latency otolithic reflexes, and sustained visuo-vestibular processing remains incompletely defined. To describe four clinical–physiological cases in which SVIN was dominant or disproportionate relative to the canal, otolithic-reflex, and sustained-domain profiles, and to propose a temporal-domain interpretation of this physiological non-congruence. Methods: Four patients with persistent disequilibrium, episodic vertigo, or selective vestibular-reflex dissociation underwent multidomain neuro-otological assessment, including bedside examination, video head impulse test/head impulse paradigm (vHIT/HIMP), suppression head impulse paradigm (SHIMP) when available, cervical and ocular vestibular-evoked myogenic potentials (cVEMPs and oVEMPs), rotatory or caloric testing when available, and optokinetic or other visuo-vestibular paradigms. SVIN was elicited by 100-Hz mastoid vibration and characterized by direction, dimensionality, stimulation-site dependence, reproducibility, and slow-phase velocity when available. Results: SVIN remained clinically informative across patients with preserved, minimally abnormal, or selectively dissociated canal and otolithic-reflex findings. The recurring feature was not normality of all conventional tests, but physiological non-congruence between the vibration-induced ocular response and the canal, otolithic-reflex, or sustained-domain profile. One patient showed normal six-canal vHIT and symmetric VEMPs despite an exceptionally large fixed-direction SVIN; another showed selective cVEMP absence with preserved oVEMPs and normal vHIT. Atypical multidimensional SVIN coexisted with marked optokinetic directional asymmetry in the adolescent case. Conclusions: SVIN is not a surrogate for vHIT, VEMPs, caloric, rotatory, or velocity-storage-related testing. It should be interpreted as a distinct phase-locked probe of vibration-sensitive vestibular imbalance. Irregular afferents provide the supported physiological framework, whereas dimorphic afferents represent a plausible, hypothesis-generating bridge population capable of contributing to otherwise unexplained clinicophysiological dissociations. Full article

Background: The video head impulse test (vHIT) is a standard tool for assessing semicircular canal function through vestibulo-ocular reflex (VOR) gain and corrective saccades (CS). Although reduced gain accompanied by CS typically indicates vestibular hypofunction, a paradoxical pattern—normal gain with CS—is occasionally observed, and its clinical significance remains unclear. Methods: We retrospectively analyzed 1573 patients who underwent both vHIT and bithermal caloric testing between September 2022 and September 2025. Among them, 1174 subjects with normal bilateral horizontal VOR gains (0.8–1.2) were evaluated for CS. CS were defined as at least three consistent refixation saccades on one side, verified visually. Subjects were categorized into Right-, Left-, and Bilateral-CS groups. Comparisons were made between CS(+) and CS(−) sides, as well as among groups, using paired and one-way ANOVA tests. Results: CS were identified in 46.3% (544 in 1174) of subjects with normal VOR gains, most frequently on the right side. The side showing CS exhibited significantly lower caloric responses than the contralateral side (p < 0.001). Bilateral CS were more common in older patients. Canal paresis values indicated that the CS side corresponded to the weaker caloric side, suggesting subtle unilateral hypofunction. Conclusions: Even with normal gain, the presence of CS may reflect mild vestibular asymmetry rather than a benign artifact. In addition, bilateral CS were associated with older age, suggesting a possible contribution of age-related vestibular or compensatory mechanisms. Careful control of methodological biases and integration with other vestibular tests are essential for interpretation. Full article

Background: The vestibular system has traditionally been interpreted within a reflex-based framework, mainly centered on gaze stabilization, vestibulo-ocular reflex pathways, and peripheral vestibular deficits. This model remains essential, but it is insufficient to explain the full spectrum of postural, perceptual, visual-motion, and self-motion complaints observed in contemporary clinical otoneurology. Objective: This conceptual narrative review examines selected representative works by Kathleen E. Cullen as landmarks in a broader transition from reflex physiology to predictive, multimodal, context-dependent, body-centered self-motion control. Methods: This is not a systematic or bibliometric review. Papers were selected because they mark distinct conceptual steps in Cullen’s work: neural encoding of self-motion, peripheral and central coding strategies, multimodal integration, active versus passive self-motion, reafference suppression, body-centered encoding, proprioceptive prediction, vestibular cerebellar internal models, sensory reweighting, and clinical translation. Synthesis: Angelaki and Cullen’s 2008 synthesis and Cullen’s subsequent work demonstrate that vestibular processing is inherently multimodal from the earliest central stages and that neural representations of self-motion depend on behavioral context. Vestibular nuclei, visual-vestibular networks, and vestibular cerebellar circuits integrate labyrinthine signals with optic flow, proprioceptive, oculomotor, motor, cerebellar, cortical, and contextual information. This architecture enables the brain to distinguish expected from unexpected motion, suppress predictable vestibular reafference during voluntary action, compute internal estimates of body motion, adapt to altered sensory reliability, and reweight sensory inputs according to task demands. Conclusions: The clinical relevance of this trajectory is substantial. Patients may show preserved high-acceleration vestibulo-ocular reflex responses while experiencing persistent instability, visually induced dizziness, defective self-motion perception, or abnormal sustained vestibular processing. Such dissociations are not paradoxical when the vestibular system is understood as a predictive, distributed, body-centered control system. Cullen’s long lesson offers a neurophysiological foundation for a modern vestibular grammar in which clinical findings are interpreted across the reflexive, perceptual, postural, visual-vestibular, sustained, and predictive domains. Full article

Horizontal nystagmus is still commonly interpreted at the bedside through a pragmatic peripheral-versus-central dichotomy. Although this heuristic is often clinically useful, it may be misleading because distributed brainstem–cerebellar disorders can generate peripheral-appearing phenotypes. This paper presents a narrative clinical–conceptual review proposing that a substantial subset of horizontal nystagmus patterns may be understood more coherently as expressions of dysfunction within a coupled vestibulo-ocular integrative network rather than as direct signatures of a single lesion site. Within this framework, two core dynamical domains are separated conceptually: a vestibular nuclei (VN)-centered velocity-storage process and an NPH-centered gaze-holding integrator. These processes are proposed to operate under cerebellar regulatory influence, with the nodulus–uvula (NU) acting as a plausible regulator of storage gain, temporal persistence, adaptation stability, and oscillatory behavior. Clinically, the velocity-storage domain is expressed through low-frequency vestibulo-ocular reflex behavior and optokinetic after-nystagmus-related dynamics, whereas the gaze-holding domain is expressed through eccentric gaze stability, gaze-evoked nystagmus, and post-saccadic drift. This framework carries a clinically relevant implication: horizontal nystagmus phenotypes may be interpreted more effectively by asking which functional process is predominantly abnormal—gaze holding, storage-related vestibular persistence, or cerebellar regulatory stability—rather than by relying solely on a binary peripheral–central label. On this basis, we outline a clinician-facing workflow linking gaze dependence, periodicity, direction reversals, head-shaking behavior, and Alexander-law mismatch to operational bedside criteria and candidate quantitative readouts. The proposed model is intended as a clinical–conceptual framework rather than a deterministic localization tool. Its main value lies in organizing discordant vestibular findings, strengthening the mechanistic interpretation of bedside and instrumented observations, and identifying testable directions for future validation studies in acute dizziness and ocular motor disorders. Full article

Background/Objectives: Recurrent acute otitis media (AOM) in children is known to cause cumulative cochlear and vestibular injury. Whether a single fulminant episode severe enough to require surgical intervention produces an analogous long-term audiovestibular signature, and whether infection severity contributes to outcome independently of cumulative episode count, is unclear. The present study addressed this gap. Methods: In this single-centre retrospective cohort study, 65 paediatric patients who had undergone surgical treatment for acute mastoiditis—the fulminant form of AOM—between July 2001 and March 2021 were assessed a median of 11.5 years after surgery. Of these, 35 had undergone mastoidectomy with tympanostomy and 30 had undergone tympanostomy alone because their episode had not been severe enough to require mastoidectomy. Thirty-two age-matched healthy volunteers (one ear each) formed the control group, yielding 97 ears in three groups (Group TM, 35 ears; Group T, 30 ears; Group C, 32 ears). Extended high-frequency pure-tone audiometry (125–20 kHz), distortion-product otoacoustic emissions (DPOAEs), single-frequency and wideband tympanometry, ipsilateral acoustic reflex thresholds, and lateral-canal vestibulo-ocular reflex gain were measured. Results: Both operated groups showed significantly elevated audiometric thresholds in the high- and extended high-frequency ranges compared with controls (HTA: χ² = 24.25, p < 0.001), with corresponding reductions in DPOAE amplitudes (HTA: χ² = 25.04, p < 0.001). Group TM did not differ significantly from Group T at any frequency band, indicating a negligible additional contribution of mastoidectomy itself. Acoustic reflex thresholds were elevated in Group TM. Vestibulo-ocular reflex gain was within reference ranges in all groups. Conclusions: A single fulminant episode of acute middle-ear infection in childhood—whether severe enough to require mastoidectomy or treated by tympanostomy alone—was associated, more than a decade later, with significantly elevated audiometric thresholds closely resembling those reported after multiple recurrent infections, supporting an effect of infection severity independent of cumulative episode count. Long-term audiological follow-up with extended high-frequency audiometry and otoacoustic emission testing is warranted, irrespective of whether mastoidectomy was required. Full article

Background and Clinical Significance: Vestibular drop attacks are a rare but disabling manifestation of Ménière’s disease. This study aimed to demonstrate the value of multimodal audiovestibular assessment in documenting vestibular deficit after intratympanic gentamicin therapy. Case presentation: A 57-year-old woman with refractory Tumarkin crises underwent serial audiological and vestibular testing before and after intratympanic gentamicin treatment. Post-treatment testing demonstrated right-sided vestibular hypofunction with caloric areflexia, reduced vestibulo-ocular reflex gain, corrective saccades on video head impulse testing, and absent cervical vestibular-evoked myogenic potentials. Hearing thresholds showed transient deterioration with near-baseline recovery during follow-up. Vestibular drop attacks resolved completely. Conclusions: Multimodal audiovestibular assessment provides objective documentation of treatment-induced vestibular hypofunction after intratympanic gentamicin therapy in refractory Ménière’s disease. Full article

Background/Objectives: Auditory neuropathy spectrum disorder (ANSD) is a well-established hearing disorder in the pediatric population and is estimated to account for at least 10% of children with sensorineural hearing loss. Compared to auditory function, vestibular function in children with ANSD has not been well described in the past. The purpose of this study is to examine vestibular testing results in children with ANSD and to better characterize vestibular dysfunction in these children. Methods: A retrospective review of vestibular laboratory testing results was conducted in pediatric patients diagnosed with ANSD. Vestibular evaluation included vestibular evoked myogenic potential (VEMP), rotary chair test, video head impulse test (vHIT), and videonystagmography (VNG). Results: A total of 30 pediatric patients with ANSD were identified, including 18 boys and 12 girls, with a mean age of 4.5 years. Bilateral ANSD was found in 24 cases, while 6 cases were unilateral. Etiologies of ANSD included a history of hyperbilirubinemia in infancy, cochlear nerve dysplasia, genetic-related conditions, etc. Vestibular dysfunction was found in 12 cases, as indicated by at least one abnormal outcome in VEMP, vHIT, or rotary chair testing. Nineteen children were cochlear implant candidates and eventually underwent unilateral or bilateral implantation. Conclusions: Vestibular dysfunction is significant in pediatric patients with ANSD, and vestibular outcomes appear to be related to underlying etiologies. Formal vestibular evaluation is necessary to identify such vestibular losses, and these findings will be helpful to guide clinical management and rehabilitation strategies for these children. Full article

Motorist’s disorientation syndrome (MDS) is seen in 1 to 5% of patients in a tertiary neurotology clinic and remains an underdiagnosed pathology. It was first described in 1985 by Page & Gresty, using the term “visual vertigo”. Patients described sensations of veering or turning over while driving an automobile when visual input was restricted. This was exacerbated at high speeds, on winding roads, going down hills, or when overtaken by a vehicle. All patients in this initial study had peripheral or central neurotological abnormalities and showed exaggerated responses during optokinetic stimulation. Some sufferers considered giving up driving. The first aims of this narrative review were to delineate the symptoms of MDS as detailed in the literature, to outline precipitating situations and to discuss associated pathologies such as anxiety. The second aim was to differentiate MDS from similar syndromes, such as persistent postural-perceptual dizziness (PPPD) and motion sickness (MS). In addition, we looked at the role of vestibular assessments and discussed the involvement of the otolith organs and semicircular canals. In this review, eight publications were analyzed. MDS is related to a visual-vestibular or a visio-visual conflict and occurs in drivers (both males and females). It is associated with anxiety in 17–39% of cases. Mild vestibular-test abnormalities or exaggerated response to opto-kinetic stimulations are seen in 60–100% of cases. Between 50 and 62% of patients have a migraine history. Convergence and strabismic problems are also often seen. Symptoms usually settle after 6 ± 4 years but can persist for longer in females. MDS is multifactorial, and similar to certain forms of PPPD but different than MS. Its pathophysiology is still in question, and we support the role of the velocity storage integrator as a recent hypothesis. Treatment includes vestibular rehabilitation, virtual reality, cognitive behavioral therapies and orthoptic sessions, and the results are promising. The authors also strongly feel that future research on clarifying MDS pathology should study a wider scope of vestibular assessments to evaluate semicircular canal/otolithic function, as well as the vestibulo-ocular reflex, analyze optokinetic nystagmus time constant, and perform a systematic orthoptic examination. Full article

Background/Objectives: Pregnancy involves significant hormonal, cardiovascular, and physiological shifts that may potentially affect the vestibular system. The utricle and saccule, the two primary otolith organs, are responsible for detecting linear acceleration and maintaining equilibrium. This study aims to objectively evaluate the functional status of these organs throughout the three trimesters of pregnancy using Vestibular Evoked Myogenic Potentials (VEMPs). Methods: A prospective cross-sectional study was conducted with 64 healthy primigravida women (mean age 29.4 ± 2.3 years). Cervical VEMP (cVEMP) and ocular VEMP (oVEMP) tests were performed at three distinct time points: the first (8–9 weeks), second (20–21 weeks), and third (33–34 weeks) trimesters. Latencies (p13 and n23 for cVEMP; n10 and p15 for oVEMP) and peak-to-peak amplitudes were recorded and statistically compared across trimesters. Results: No statistically significant differences were found in cVEMP p13 and n23 latencies or amplitudes across the three trimesters (p > 0.05). Similarly, oVEMP p15 latencies and amplitudes remained stable throughout the pregnancy (p = 0.43 and p = 0.95, respectively). While a slight numerical increase in certain latencies was observed in the third trimester, and the oVEMP n10 latency was found to be consistently prolonged compared to non-pregnant norms, these values remained stable between trimesters. The inter-aural asymmetry showed no significant deviations, indicating a balanced vestibular adaptation. Conclusions: The functional integrity of the saccule and utricle is preserved during a healthy pregnancy. Despite the dramatic increase in gestational hormones such as estrogen and progesterone, the otolith-dependent reflex pathways (vestibulocollic and vestibulo-ocular) remain resilient. These results provide a clinical baseline for evaluating vestibular symptoms in pregnant populations, suggesting that significant VEMP abnormalities should prompt investigation into underlying vestibular pathologies rather than being attributed to normal pregnancy changes. Full article

Post-traumatic auditory and vestibular complaints are frequent after traumatic brain injury (TBI) and temporal bone trauma. They create particular difficulty in medico-legal practice because the evaluator must distinguish diagnosis, functional impact, plausibility of traumatic causation, and the credibility of reported deficits and/or symptoms. This manuscript is a narrative expert review, not a systematic review or a validated forensic prediction rule. It aims to synthesize clinically relevant evidence and propose a practical cross-check framework for structured audio-vestibular assessment in post-traumatic and medico-legal contexts. Pure-tone audiometry remains the functional entry point, but it should be interpreted in conjunction with speech audiometry, tympanometry, acoustic reflexes, transient-evoked and distortion-product otoacoustic emissions, auditory brainstem responses, and auditory steady-state responses. Vestibular evaluation should combine videonystagmography, video head impulse testing, cervical and ocular vestibular evoked myogenic potentials, and computerized dynamic posturography, recognizing that each method interrogates different physiological domains and frequencies. Particular emphasis is placed on the separation between clinical diagnosis, physiological localization, functional impairment, and medico-legal attribution. The article also discusses safeguards against false-positive attribution of malingering, the time course after TBI, inter-rater variability, and the role of specialist expertise in medico-legal reporting. The proposed framework does not eliminate uncertainty; rather, it is intended to make expert reasoning transparent, cautious, internally consistent, and defensible. Full article

Background/Objectives: The cochlea and vestibular organs develop concurrently during embryogenesis and share anatomical and functional pathways. As a result, congenital factors affecting the vestibulocochlear system may impair both hearing and vestibular function. Despite this, the relationship between congenital bilateral sensorineural hearing loss (SNHL) and vestibular dysfunction remains insufficiently defined. This study evaluated vestibular function in patients with congenital bilateral SNHL and investigated the association between hearing loss severity and vestibular function. Methods: A total of 202 participants aged 7–31 years were enrolled, including 102 patients with congenital bilateral SNHL and 100 healthy controls. Vestibular function was assessed using videonystagmography (VNG) during sinusoidal harmonic acceleration (SHA) rotational testing and caloric testing performed according to the Fitzgerald–Hallpike protocol, as well as with the video head impulse test (vHIT). Statistical analyses compared vestibular parameters between groups and assessed correlations with hearing loss severity. Results: Patients with congenital bilateral SNHL exhibited significantly lower vestibulo-ocular reflex (VOR) values in the SHA test compared to controls. Greater hearing loss severity was associated with lower VOR gain values. No statistically significant differences were observed between groups in caloric test results or vHIT VOR gain values. However, corrective saccades during vHIT were identified exclusively in patients with hearing loss and occurred in approximately 15% of cases. Furthermore, the age of independent walking was significantly delayed in the study group compared to controls. Conclusions: Congenital bilateral SNHL is associated with vestibular dysfunction, as evidenced by abnormal SHA test results and the presence of corrective saccades in vHIT. These patients may also experience delayed motor development. These findings suggest that vestibular dysfunction may be present in patients with congenital sensorineural hearing loss and may have functional implications. Full article

Background: Turner syndrome is a genotypic disorder in females characterized by the total or partial absence of an X chromosome. While cardiovascular issues and sensorineural hearing loss are well-documented, vestibular system involvement remains understudied. This study aims to examine vestibular system involvement in patients with Turner syndrome and assess if they exhibit a higher prevalence of peripheral vestibular pathology compared to the general population. Methods: A retrospective longitudinal study was conducted with 21 Turner syndrome patients and 21 age-matched controls. Evaluations included clinical history, otoscopy, pure tone audiometry, the Video Head Impulse Test (vHIT) to measure vestibulo-ocular reflex gain, and computerized dynamic posturography, specifically the Sensory Organization Test (SOT) and Stability Limits Analysis. Results: Turner syndrome patients showed significantly higher hearing thresholds across all frequencies compared to controls (p < 0.001). In the vHIT, 30% of the Turner group presented pathological results, with significant gain reductions in the right horizontal and left posterior semicircular canals. Posturography revealed a significant reduction in overall stability (p = 0.006) and a significantly lower vestibular index (p = 0.011) in the Turner group. Additionally, patients with Turner syndrome demonstrated significant impairments in directional control, reaction time, and excursion points during Stability Limits Analysis. Conclusions: Patients with Turner syndrome are more likely to experience vestibular disorders, a finding likely associated with estrogen deficiency and the loss of its protective effect on the inner ear. These results highlight the necessity of including vestibular and posturographic assessments in the routine clinical follow-up of these patients to facilitate early detection and rehabilitation, even in the absence of overt symptoms like vertigo. Full article

Background/Objectives: This study compared vestibular evoked myogenic potentials (VEMP) and video head impulse test (vHIT) findings between long-term hearing aid users and non-users with moderately severe to profound sensorineural hearing loss (SNHL) to investigate whether prolonged use of high-power hearing aids has any effect on the functioning of peripheral vestibular organs. Methods: A cross-sectional study was conducted in the audiology clinic of a tertiary care hospital. Using convenience sampling, 67 adults aged 20–64 years who visited for hearing evaluation or hearing aid services were recruited and allocated into hearing aid user and non-user groups. VEMP latency and amplitude and vHIT vestibulo-ocular reflex (VOR) gain values were compared between groups. Multiple linear regression was performed to examine the association between the duration of hearing aid use and vestibular function. Results: No significant group differences were observed for any VEMP or vHIT parameter, except for the latency of P1 of the cVEMP in the left ear. Regression analyses indicated that the duration of hearing aid use was not significantly associated with any vestibular test measure. Conclusions: Long-term use of high-power hearing aids does not appear to be associated with measurable alterations in vestibular function. Nonetheless, longitudinal studies with improved control of confounding variables are recommended to validate these preliminary findings. Full article

(1) Background: Subclinical neck pain is mild-to-moderate neck pain that has not yet been treated, and where individuals experience pain-free days. Alterations in sensorimotor integration, motor control, proprioception, and cerebellar inhibition have been observed in individuals with subclinical neck pain. Upregulation of the cervico-ocular reflex is documented in subclinical neck pain, with no difference in the gain of the vestibulo-ocular reflex. Vestibulo-ocular reflex gain adaptation and associated differences in visuo-motor control have not been successfully measured in this population. This study aims to investigate the vestibulo-ocular reflex gain adaptation and visuo-motor control in individuals with subclinical neck pain. (2) Methods: 30 right-hand-dominant participants (19 healthy controls: 10 male and 9 female; 16 subclinical neck pain: 6 male and 10 female) aged 18 to 35 performed an eye tracking task. Participants were seated 90cm away from a monitor and instructed to hold their gaze on a stationary or moving target projected onto a screen while performing active head rotations. Trials were divided into 12 blocks (pre-adaptation, 10 adaptation, and post-adaptation) for a total of 192 trials. During adaptation, the target would move at increasing speeds during each block, increasing by 10% of active head velocity up to a maximum of 100%. (3) Results: The subclinical neck pain group demonstrated significantly higher total saccades (p = 0.006, ƞ² = 0.240) and overt catch-up saccades (p = 0.041, ƞ² = 0.141) than the healthy control group. (4) Conclusion: Subclinical neck pain alters the visual–vestibular interaction. Full article

Background/Objective: The Suppression Head Impulse Paradigm (SHIMP) is a specialized variant of the Head Impulse Test (HIT), designed to evaluate the suppression of the angular Vestibulo-Ocular Reflex (aVOR) by central mechanisms. These mechanisms are primarily mediated by brainstem structures, including the vestibular nuclei, their projections to ocular motor nuclei, and modulatory inputs from the cerebellum. Damage to these areas can impair the generation of anti-compensatory saccades (ACs), even when the peripheral vestibular apparatus remains intact. The present study explores this phenomenon in a cohort of patients with neurological disorders known to potentially involve the brainstem, including multiple sclerosis, severe traumatic brain injury, stroke, and Parkinson’s disease. Methods: This cross-sectional study included 119 patients with multiple sclerosis (PwMS), severe traumatic brain injury (PwTBI), stroke (PwS), and Parkinson’s disease (PwPD). The video Head Impulse Test was performed to assess the aVOR gain across all semicircular canals using both the HIMP and SHIMP. The presence, absence, or delay of ACs was systematically recorded. Results: Among the 119 patients evaluated (238 semicircular canals), 24 (20%) demonstrated normal aVOR gain but failed to generate ACs during SHIMP. The absence of ACs was observed in seven PwMS, five with PwTBI, six with PwS, and six with PwPD. Conclusions: The absence of ACs despite normal aVOR gain suggests a potential impairment in the central pathways controlling saccadic responses, independently of peripheral vestibular function. These findings underscore the clinical relevance of integrating the SHIMP into vestibular assessments to improve the identification of central vestibular dysfunction in neurological disorders. Full article