Mecanismos neurológicos involucrados en la escoliosis idiopática. Revisión sistemática de la literatura / Neurological mechanisms involved in idiopathic scoliosis. Systematic review of the literature

La literatura que explica los mecanismos neurológicos que subyacen al desarrollo o a la compensación de la escoliosis idiopática es limitada. El objetivo del presente artículo es describir e integrar los mecanismos y las vías nerviosas por medio de las cuales se compensa y/o se desarrolla la escoliosis idiopática. Se realizó una revisión sistemática narrativa en diferentes bases de datos sobre los estudios publicados entre el 1 de enero 1967 y el 1 de abril de 2021, empleando los siguientes términos: «scoliosis», «vision», «ocular», «vestibule», «labyrinth», «posture», «balance», «eye movements», «cerebellum», «proprioception» y «physiological adaptation». En la búsqueda se identificaron 1.112 referencias, de las cuales al final se incluyeron 50: 46 estudios clínicos observacionales analítico-descriptivos (entre cohortes, reporte y serie de casos) y 4 estudios experimentales. En la respuesta neurológica a la escoliosis idiopática, la integración sensitivo-cortical de las aferencias visual-oculomotor-vestibular-propioceptiva permite realizar modificaciones a nivel postural con el fin de lograr una compensación inicial sobre el balance sagital y el centro de masa; sin embargo, con el tiempo dicho mecanismo de compensación puede agotarse y causar progresión de la deformidad inicial. (AU)

The literature that explains the neurological mechanisms underlying the development or compensation of idiopathic scoliosis is limited. The objective of the article is to describe and integrate the mechanisms and nerve pathways through which idiopathic scoliosis is compensated and/or developed. A narrative systematic review in different databases of the studies published between January 1, 1967 and April 1, 2021 was performed, using the following terms: «scoliosis», «vision», «eye», «vestibule», «labyrinth», «posture», «balance», «eye movements», «cerebellum», «proprioception», and «physiological adaptation». In the search, 1112 references were identified, of which 50 were finally included: 46 observational analytical clinical studies-descriptive (between cohorts, report and series of cases) and 4 experimental studies. In the neurological response to idiopathic scoliosis, the sensory-cortical integration of the afferences in the visual-oculomotor-vestibular-proprioceptive systems, allows modifications at the postural level in order to achieve an initial compensation on the sagittal balance and the centre of body mass; however, over time these compensation mechanisms may be exhausted causing progression of the initial deformity. (AU)

Vestibular dysfunction in cochlear implant candidates: Prevalence and outcomes.

PURPOSE: Cochlear implantation (CI) has been shown to reduce vestibular function postoperatively in the implanted ear. The objective of this study was to identify the prevalence of preoperative vestibular weakness in CI candidates and identify any risk factors for postoperative dizziness. STUDY DESIGN: Retrospective cohort study. MATERIALS AND METHODS: Patients who underwent CI and had preoperative videonystagmography (VNG) at the Silverstein Institute from January 1, 2017 to May 31, 2020 were evaluated. The primary endpoint was dizziness lasting more than one month postoperatively. RESULTS: One hundred and forty nine patients were evaluated. Preoperative VNG revealed that 46 (30.9%) had reduced vestibular response (RVR) on one side and 32 (21.5%) had bilateral vestibular hypofunction (BVH). Postoperative dizziness occurred in 14 (9.4%) patients. Patients with postoperative dizziness were more likely to have abnormal preoperative VNG (RVR or BVH), compared to patients without postoperative dizziness (78.6% versus 49.6%, p = 0.0497). In cases of RVR, implantation of the weaker or stronger vestibular ear did not affect the postoperative dizziness (16.1% versus 6.7%, p = 0.38). Postoperative VNG in patients with dizziness showed decreased caloric responses in the implanted ear (28.4 to 6.4 degrees/s, p = 0.02). CONCLUSION: Preoperative caloric weakness is prevalent in CI candidates and abnormal preoperative vestibular testing may be a predictor of postoperative dizziness. CI has the potential to cause vestibular injury and preoperative testing may aid in both counseling and decision-making.

Dizziness in Parkinson's disease patients is associated with vestibular function.

Dizziness is common in Parkinson's disease (PD) patients. It is known that orthostatic hypotension (OH) is the main cause of such dizziness, but even without OH, quite a few PD patients complain of dizziness in the clinic. It can be regarded as non-specific because most of these patients have no neurological abnormalities. We hypothesized that this type of dizziness would be associated with vestibular function, although included patients did not have clinically confirmed vestibulopathy. We studied 84 patients without OH among 121 PD patients. Their clinical features and function were compared between patients with and without dizziness. Hoehn and Yahr stage (H&Y stage), the Unified Parkinson's Disease Rating Scale (UPDRS) part III, the Korean version of the Mini-Mental State Examination (K-MMSE), education years, disease duration, total levodopa equivalent daily dose (LEDD), the presence of dizziness, the dizziness severity, and orthostatic hypotension were tested. Vestibular evoked myogenic potentials (VEMPs) were used to characterize vestibular function. Ocular (oVEMPs) and cervical (cVEMPs) were recorded. oVEMPs in the right side showed significantly reduced potentials (p = 0.016) in PD patients with dizziness, but cVEMPs did not (all ps > 0.2). Bilateral absent oVEMP responses were more common in PD patients with dizziness (p = 0.022), but the frequencies of bilateral absent cVEMP responses were not different between the dizzy and non-dizzy groups (p = 0.898). Dizziness in PD patients without orthostatic hypotension may be associated with vestibular hypofunction. Our results provide evidence that can aid clinicians when making a treatment plan for patients with dizziness. i.e., strategies to enhance reduced vestibular function may be helpful, but this suggestion remains to be evaluated.

Advantages of Short-term Personalized Vestibular Rehabilitation at Home Guided by Professional Therapist for Treatment of Decompensated Vestibular Vertigo.

OBJECTIVE: Patients suffered a lot from decompensated vestibular vertigo. Pharmacotherapy and vestibular rehabilitation training have been proven to be effective in prompting vestibular compensation. Routine rehabilitation training is faced with the challenges of patients' compliance, completion, the average recuperation time and so on. This study is aimed to investigate advantages of short-term personalized vestibular rehabihitation at home guided by professional therapist. METHODS: A short-term personalized vestibular rehabilitation program (ST-PVR) was designed for patients with decompensated vestibular vertigo in this study. RESULTS: Patients experiencing the ST-PVR program showed significant improvement of Self-Rating Anxiety Scale (SAS), Dizziness Handicap Inventory (DHI), Activities-Specific Balance Confidence Scale (ABC) scores by the second follow-up (at 2nd week after treatment, P<0.05). However-improvement in the medication group occurred slightly later, DHI for 1 month and SAS for 2 months after treatment (P<0.05). Also, the improvement in the onset time of unilateral weakness (UW) at 2nd week after treatment in the personalized vestibular rehabilitation (PVR) group was faster than that in the medication group. CONCLUSION: In general, the short-term PVR program showed great advantages by prompting vestibular compensation quickly and putting forward future direction for clinical treatment on decompensated vestibular vertigo.

Evaluation of Vestibular Function in Diagnosis of Vestibular Schwannomas.

Vestibular schwannomas (VS) are benign tumors of the vestibular nerve. The common first symptoms are hearing loss and tinnitus, followed by imbalance, vertigo, and facial nerve involvement. The subjective symptoms of VS patients are not consistent with the severity of vestibular lesions and the results of vestibular tests, which often interfere with clinicians' diagnoses. Thus, the main screening and diagnostic methods for VS are audiometry and magnetic resonance imaging (MRI), ignoring the evaluation of vestibular function at the source of pathological lesions. With the development and improvement of vestibular evaluation technology and its wide application in the clinic, modern vestibular examination technology can reflect the severity and frequency of vestibular lesions and compensation from multiple perspectives, providing an objective basis for the diagnosis and treatment of vestibular diseases. In this report, we review the results and characteristics of vestibular tests in VS patients and further clarify the clinical value of vestibular function assessment in the diagnosis and treatment of VS.

Retro-labyrinthine Lesion Site Detected by Galvanic Vestibular Stimulation Elicited Vestibular-evoked Myogenic Potentials in Patients with Auditory Neuropathy.

OBJECTIVE: Auditory neuropathy (AN) is a unique pattern of hearing loss with preservation of hair cell function. The condition is characterized by the presence of otoacoustic emissions (OAE) or cochlear microphonic (CM) responses with severe abnormalities of the auditory brainstem response (ABR). The vestibular branches of the VIII cranial nerve and the structures innervated by it can also be affected. However, the precise lesion sites in the vestibular system are not well characterized in patients with AN. METHODS: The air-conducted sound (ACS) vestibular-evoked myogenic potentials (VEMPs) and galvanic vestibular stimuli (GVS)-VEMPs were examined in 14 patients with AN. RESULTS: On examination of VEMPs (n=14, 28 ears), the absent rates of ACS-cervical VEMP (cVEMP), ACS-ocular VEMP (oVEMP), GVS-cVEMP, GVS-oVEMP and caloric test were 92.9% (26/28), 85.7% (24/28), 67.9% (19/28), 53.6% (15/28), and 61.5% (8/13), respectively. Impaired functions of the saccule, inferior vestibular nerve, utricle, superior vestibular nerve, and horizontal semicircular canal were found in 25.0% (7/28), 67.9% (19/28), 32.1% (9/28), 53.6% (15/28) and 61.5% (8/13) patients, respectively. On comparing the elicited VEMPs parameters of AN patients with those of normal controls, both ACS-VEMPs and GVS-VEMPs showed abnormal results in AN patients (such as, lower presence rates, elevated thresholds, prolonged latencies, and decreased amplitudes). CONCLUSION: The study suggested that patients with AN often have concomitant vestibular disorders. Retro-labyrinthine lesions were more frequently observed in this study. GVS-VEMPs combined with ACS-VEMPs may help identify the lesion sites and facilitate detection of areas of vestibular dysfunction in these patients.

Vestibular and oculomotor function in patients with vestibular migraine.

AIM: The purpose of this study was to assess the vestibular and oculomotor function in patients with vestibular migraine (VM). And we also investigate the relationship between testing results and effectiveness of preventive medications in VM. MATERIAL AND METHOD: 41 patients with VM were recruited in this study and examined with cervical and ocular vestibular evoked myogenic potential(cVEMP, oVEMP), video head impulse test(vHIT), caloric test and videonystagmography. All patients were treated with preventive medications. We calculated symptomatic improvement and record episodes frequency in patients with VM. Six months later, the effectiveness of preventive medications were evaluated and the relationship between vestibular testing and effectiveness of preventive medications were analyzed further. RESULTS: In vestibular function testing, 73% of patients with VM showed abnormal results. Abnormal cVEMP, oVEMP, vHIT, and caloric test were found in 20%, 44%, 32% and 56% respectively. The abnormal rate of oVEMP was significantly higher than that of cVEMP(p < 0.05). And the proportion of abnormal caloric test was obviously higher than that of vHIT (p < 0.05). In oculomotor function testing, 42% of the patients with VM showed pathological results which was significantly lower than that of vestibular function testing(p < 0.05). After 6 months follow-up, the proportion of prophylactic medication effectiveness was significantly higher in normal vestibular function testing group compared with the abnormal group (p < 0.05). CONCLUSION: Abnormal vestibular and oculomotor functions are commonly observed in patients with VM. And these patients with abnormal vestibular function possess a weak effectiveness of preventive medications.

Evaluation of the Vestibulocochlear System in Patients with Pseudoexfoliation Syndrome

Objectives: Patients with pseudoexfoliation syndrome (PES) can also have sensorineural hearing loss as well as balance problems. Our aim was to evaluate vestibulocochlear system involvement in PES patients. Materials and Methods: The study included 16 subjects with PES (study group) with a mean age of 66.12±5.64 years and 17 healthy subjects (control group) with a mean age of 61.70±8.46 years. Both groups underwent ophthalmological, neuro-otological, audiological, and vestibular evaluation. Pure-tone audiometry and tympanometry were performed as audiological tests and bithermal caloric test and vestibular-evoked myogenic potential (VEMP) testing were used as vestibular tests. The Romberg, tandem Romberg, and Unterberger tests were also performed. Results: In the PES group, bithermal caloric tests revealed right canal paresis in 6 patients, left canal paresis in 3 patients, and bilateral stimulation loss in 2 patients, despite no clinical evidence of balance loss. Paresis was not detected in any of the control subjects. Unilateral VEMP responses could not be obtained in 3 patients in the PES group. The ocular PES patients whose VEMP waves were obtained differed significantly from the control group (p<0.05). In office tests for vestibular evaluation, pathologic findings were found in 7 of 16 patients in the study group and only 4 subjects in the control group. Audiological evaluation with pure-tone thresholds revealed sensorineural decline at 4000 and 8000 Hertz in the PES patients. A statistically significant difference was found between the study group and the control group (p<0.05). Conclusion: Patients with PES showed elevation in pure-tone thresholds and a decrease in superior and inferior vestibular nerve function, demonstrating that the vestibular system as well as the auditory system are affected in PES.

[Vertigo and dizziness].

Pathophysiology of vertigo/dizziness can be understood by eye deviation (nystagmus). In benign paroxysmal positional vertigo, eye deviation of causative semicircular canal stimulation is directly observed. In other peripheral vestibular disorders, eye deviation results from the sum of unilateral all semicircular canal disorders. The central vestibular pathway is controlled by the cerebellum. Thus, in vertigo/dizziness of central origin, not only eye deviation due to impairment of the central vestibular pathway but also deviation due to disinhibition of the pathway from the cerebellum is observed. The cerebellar control on the central vestibular pathway also plays an important role in vestibular compensation. When treating vertigo/dizziness, it is necessary to understand the pathophysiology of the vertigo/dizziness, to set the treatment target based on the pathophysiology, and to intervene for the target.

Sudden Sensorineural Hearing and Vestibular Loss in a Case of Relapsing Polychondritis.

OBJECTIVES: To report a case of profound bilateral sensorineural hearing and vestibular loss from relapsing polychondritis and hearing outcomes after cochlear implantation. METHODS: Case report and literature review. RESULTS: A 43 year-old woman developed sudden loss of hearing and balance that progressed over several weeks to bilateral, profound hearing and vestibular loss. Steroid treatments were ineffective. She underwent vestibular physical therapy and left cochlear implantation. About 10 months after her initial presentation, she developed erythema, warmth, swelling, and pain of the left auricle sparing the lobule, flattening of the bridge of her nose, and right ankle swelling, warmth, and skin erythema. A biopsy of the left auricle revealed histopathologic findings consistent with relapsing polychondritis. She was treated with high dose prednisolone. The ear inflammation resolved, however, despite excellent auditory response to pure tone thresholds, the patient reported no improvement in speech perception after cochlear implantation. CONCLUSIONS: Relapsing polychondritis can present with rapidly progressive, profound loss of hearing and vestibular function. Hearing outcomes after cochlear implantation can include poor speech discrimination despite good pure tone detection thresholds.

Altered Vestibular Balance Function in Combat Sport Athletes.

Combat sports pose a risk for accumulative injuries to the nervous system, yet fighters have remained an understudied population. Here, our purpose was to determine whether repetitive blows to the head have an effect on vestibular balance reflexes in combat sports athletes. We compared lower-limb muscle responses evoked with electrical vestibular stimuluation (EVS) between fighters (boxing/muay thai) and non-fighter controls. Each participant received stochastic vestibular stimulation (0-25 Hz, ±3 mA) over their mastoid processes while they stood relaxed with their head to the left or right. Surface electromyography was recorded from the medial gastrocnemius and soleus muscles bilaterally. Short and medium latency response (SLR/MLR) peaks were significantly delayed in the fighter group compared to controls. SLR and MLR peak amplitudes were also significantly lower in fighters. Fighter-estimated cumulative repetitive head impact (RHI) events demonstrated strong positive correlations with the timing of SLR and MLR peaks. Cumulative RHI events also negatively correlated with peak MLR amplitude and response gain at frequencies above 5 Hz. Our results provide evidence of a progressive vestibular impairment in combat sports athletes, potentially resulting from blows to the head accumulated in sparring practice and competitive bouts throughout their careers. Taken together, EVS-based vestibular assessments may provide a valuable clinical diagnostic tool and help better inform "return-to-play" and career-length decisions for not only combat sports athletes, but potentially other populations at risk of RHIs.

Effect of noisy galvanic vestibular stimulation on dynamic posture sway under visual deprivation in patients with bilateral vestibular hypofunction.

A single-blind study to investigate the effects of noisy galvanic vestibular stimulation (nGVS) in straight walking and 2 Hz head yaw walking for healthy and bilateral vestibular hypofunction (BVH) participants in light and dark conditions. The optimal stimulation intensity for each participant was determined by calculating standing stability on a force plate while randomly applying six graded nGVS intensities (0-1000 µA). The chest-pelvic (C/P) ratio and lateral deviation of the center of mass (COM) were measured by motion capture during straight and 2 Hz head yaw walking in light and dark conditions. Participants were blinded to nGVS served randomly and imperceivably. Ten BVH patients and 16 healthy participants completed all trials. In the light condition, the COM lateral deviation significantly decreased only in straight walking (p = 0.037) with nGVS for the BVH. In the dark condition, both healthy (p = 0.026) and BVH (p = 0.017) exhibited decreased lateral deviation during nGVS. The C/P ratio decreased significantly in BVH for 2 Hz head yaw walking with nGVS (p = 0.005) in light conditions. This study demonstrated that nGVS effectively reduced walking deviations, especially in visual deprived condition for the BVH. Applying nGVS with different head rotation frequencies and light exposure levels may accelerate the rehabilitation process for patients with BVH.Clinical Trial Registration This clinical trial was prospectively registered at www.clinicaltrials.gov with the Unique identifier: NCT03554941. Date of registration: (13/06/2018).

Geriatric sudden deafness.

PURPOSE: Sudden sensorineural hearing loss, briefly sudden deafness (SD), in the elderly remains less investigated despite rapidly aging population in most countries around the world. This study investigated whether aging process affects the treatment outcome of SD in the elderly. PATIENTS AND METHODS: Eighty patients with SD, comprising 40 geriatric patients aged >65 years and 40 non-geriatric patients aged 55-64 years, were enrolled in this study. All patients underwent an inner ear test battery including audiometry, and cervical vestibular-evoked myogenic potential (cVEMP), ocular VEMP (oVEMP), and caloric tests. RESULTS: Pre-treatment mean hearing level in the geriatric group (94 ± 16 dB) did not significantly differ from non-geriatric group (89 ± 20 dB). After treatment for 3 months, mean hearing gain in the geriatric group (22 ± 18 dB) with an improvement rate of 65%, did not significantly differ from non-geriatric group (21 ± 28 dB) with 58% improvement rate. Both inter-subject and intra-subject analyses revealed that the aging process greatly influenced the cVEMP and oVEMP responses, while less influenced the caloric responses. CONCLUSION: The treatment outcome of SD in geriatric patients aged >65 years did not significantly differ from that in non-geriatric patients aged 55-64 years, indicating that aging process did not affect treatment outcome of SD. Unlike treatment outcome for the presbycusis is unsatisfactory, treatment outcome for the elderly with SD could be favorable.

Vestibular involvement of PFAPA syndrome.

OBJECTIVE: PFAPA syndrome is derived from the initials of the English words of the findings that make up the syndrome ("Periodic Fever", "Aphthous Stomatitis", "Pharyngitis", "Adenitis"). This study aims to evaluate the vestibular system in patients with PFAPA syndrome by the cVEMP test and to give a general review of PFAPA syndrome in light of current literature. METHODS: In this prospective study, 30 patients aged 4-6 who were diagnosed with PFAPA in a tertiary pediatrics clinic, between January 2016 and February 2020 and 30 children of the same age group who applied to a tertiary otorhinolaryngology clinic for other reasons and proven to have no hearing or vestibular problems were included and in addition to routine physical examination, electromyographic activity of the sternocleidomastoid muscle surface was measured. RESULTS: We found that the amplitude difference between cVEMP p1-n1 in patients with PFAPA syndrome in both ears decreased compared to the healthy control group. CONCLUSION: Our study proves there is a vestibular system involvement of PFAPA syndrome. This study is the first in the literature to search the relationship between PFAPA and the vestibular system.

Vestibular agnosia in traumatic brain injury and its link to imbalance.

Vestibular dysfunction, causing dizziness and imbalance, is a common yet poorly understood feature in patients with TBI. Damage to the inner ear, nerve, brainstem, cerebellum and cerebral hemispheres may all affect vestibular functioning, hence, a multi-level assessment-from reflex to perception-is required. In a previous report, postural instability was the commonest neurological feature in ambulating acute patients with TBI. During ward assessment, we also frequently observe a loss of vertigo sensation in patients with acute TBI, common inner ear conditions and a related vigorous vestibular-ocular reflex nystagmus, suggesting a 'vestibular agnosia'. Patients with vestibular agnosia were also more unbalanced; however, the link between vestibular agnosia and imbalance was confounded by the presence of inner ear conditions. We investigated the brain mechanisms of imbalance in acute TBI, its link with vestibular agnosia, and potential clinical impact, by prospective laboratory assessment of vestibular function, from reflex to perception, in patients with preserved peripheral vestibular function. Assessment included: vestibular reflex function, vestibular perception by participants' report of their passive yaw rotations in the dark, objective balance via posturography, subjective symptoms via questionnaires, and structural neuroimaging. We prospectively screened 918 acute admissions, assessed 146 and recruited 37. Compared to 37 matched controls, patients showed elevated vestibular-perceptual thresholds (patients 12.92°/s versus 3.87°/s) but normal vestibular-ocular reflex thresholds (patients 2.52°/s versus 1.78°/s). Patients with elevated vestibular-perceptual thresholds [3 standard deviations (SD) above controls' average], were designated as having vestibular agnosia, and displayed worse posturography than non-vestibular-agnosia patients, despite no difference in vestibular symptom scores. Only in patients with impaired postural control (3 SD above controls' mean), whole brain diffusion tensor voxel-wise analysis showed elevated mean diffusivity (and trend lower fractional anisotropy) in the inferior longitudinal fasciculus in the right temporal lobe that correlated with vestibular agnosia severity. Thus, impaired balance and vestibular agnosia are co-localized to the inferior longitudinal fasciculus in the right temporal lobe. Finally, a clinical audit showed a sevenfold reduction in clinician recognition of a common peripheral vestibular condition (benign paroxysmal positional vertigo) in acute patients with clinically apparent vestibular agnosia. That vestibular agnosia patients show worse balance, but without increased dizziness symptoms, explains why clinicians may miss treatable vestibular diagnoses in these patients. In conclusion, vestibular agnosia mediates imbalance in traumatic brain injury both directly via white matter tract damage in the right temporal lobe, and indirectly via reduced clinical recognition of common, treatable vestibular diagnoses.

Vestibular phenotype-genotype correlation in a cohort of 90 patients with Usher syndrome.

Usher syndrome has been historically categorized into one of three classical types based on the patient phenotype. However, the vestibular phenotype does not infallibly predict which Usher genes are mutated. Conversely, the Usher syndrome genotype is not sufficient to reliably predict vestibular function. Here we present a characterization of the vestibular phenotype of 90 patients with clinical presentation of Usher syndrome (59 females), aged 10.9 to 75.5 years, with genetic variants in eight Usher syndromic genes and expand the description of atypical Usher syndrome. We identified unexpected horizontal semicircular canal reactivity in response to caloric and rotational stimuli in 12.5% (3 of 24) and 41.7% (10 of 24), respectively, of our USH1 cohort. These findings are not consistent with the classical phenotypic definition of vestibular areflexia in USH1. Similarly, 17% (6 of 35) of our cohort with USH2A mutations had saccular dysfunction as evidenced by absent cervical vestibular evoked myogenic potentials in contradiction to the classical assumption of normal vestibular function. The surprising lack of consistent genotypic to vestibular phenotypic findings as well as no clear vestibular phenotypic patterns among atypical USH cases, indicate that even rigorous vestibular phenotyping data will not reliably differentiate the three USH types.

Air and bone-conducted vestibular evoked myogenic potentials in children with large vestibular aqueduct syndrome.

BACKGROUND: There are few studies focused on vestibular symptoms and function of the children with LVAS. OBJECTIVES: This study aimed to find the characteristics of air and bone-conducted VEMPs among children with LVAS, and to investigate the relationship between VEMPs and vestibular symptoms. MATERIAL AND METHODS: A total of 44 children with LVAS and 10 healthy children were recruited as the case group and control group. Air and bone-conducted VEMP were performed to the participants. RESULTS: For air-conducted measurement, there was elevated amplitude of cVEMP in case group than control group. There was no significant difference at oVEMP parameters between the case group and control group. For bone-conducted measurement, significantly longer P1 latency and shorter P1-N1 latency of cVEMP were observed among the case group; there were a series of changes in oVEMP parameters among the case group. Logistic regression model revealed that air-conducted oVEMP asymmetric ratio was valuable to predict vestibular symptoms' development among the kids with LVAS. CONCLUSION: Asymmetric ratio of oVEMP could be used as one predictor of developing vestibular symptoms of the children with LVAS. Applying bone-conducted VEMP as one alternative parameter of vestibular syndrome is novel and will certainly remain an area of continued investigation.

Misperception of Visual Vertical in Peripheral Vestibular Disorders. A Systematic Review With Meta-Analysis.

OBJECTIVE: The main aim was to assess the misperception of visual verticality (VV) in patients with peripheral vestibular disorders (PVD) in comparison with healthy controls. As secondary objectives, we checked if vestibular, visual, and somatosensory postural pathways can be affected in patients with PVD as well as the characteristics of PVD that could influence on the VV perception. METHODS: A systematic review with meta-analysis was carried out. The bibliographic search was performed in January, 2020 in PubMed, Scopus, Web of Science (WOS), CINAHL, SciELO. Two reviewers selected the studies that met the inclusion criteria, extracted data, and assessed the methodological quality using the Newcastle-Ottawa Scale (NOS). The VV perception was assessed in two meta-analysis according the used test: The Subjective Visual Vertical test (SVV) or the Rod and Frame Test (RFT) in comparison with healthy subjects. The Standardized Mean Difference (SMD) and its 95% Confidence Interval (95% CI) was used to estimate the pooled effect. Publication bias was assessed using the Egger's test and Trim and Fill Method. RESULTS: Thirty-four studies were included reporting 3,524 participants. PVD patients showed a misperception of the VV with SVV (SMD = 1.510; 95%CI: 1.190-1.830) and the RFT (SMD = 0.816; 95% CI: 0.234-1.398) respect healthy controls. A subgroup of patients in the acute phase (SMD = 2.5; 95%CI: 2.022-2.978) and who underwent a vestibular surgery (SMD = 2.241; 95%CI: 1.471-3.011) had the greater misperception of VV. CONCLUSION: Patients with PVD show an alteration in the perception of VV, being greater in the acute phase and after a vestibular surgery. Laryngoscope, 131:1110-1121, 2021.

The influence of type of visual image and gender on the perception of horizontality: a subjective visual horizontal (SVH) study.

BACKGROUND: The graviceptive otolith function can be measured using subjective visual horizontal (SVH) testing. Nevertheless, more research efforts are required to understand the essential variables affecting SVH. OBJECTIVE: The aim of the present study was to determine the effects of type of visual image and gender on subjective visual horizontal (SVH) perception among healthy adults. MATERIALS AND METHODS: In this comparative study, 50 healthy young adults were enrolled. While in an upright body position, they were required to report their perception of horizontality for two types of visual images (solid line and arrow pattern) using a computerized SVH device. RESULTS: The arrow pattern produced significantly bigger SVH angles than the solid line (p < .001). In contrast, no significant influence of gender was found on SVH results (p = .743), Based on the statistical outcomes, the preliminary normative data for SVH were established. CONCLUSIONS AND SIGNIFICANCE: The arrow pattern (a more complex visual image) produced bigger SVH deviations than the simple solid line image. In contrast, the horizontality perception does not appear to be affected by gender. The preliminary normative SVH data gathered from the present study can be beneficial for clinical and future research applications.