Journal of Vestibular Research-Equilibrium & Orientation最新文献

Objective: We aimed to identify the proportion of each medical condition or disease contributing to dizziness and their disposition in the Emergency Department (ED).

Methods: This retrospective, descriptive study examined data from the Osaka Emergency Information Research Intelligent Operation Network system in Japan for the period from January 1, 2018 to December 31, 2020. The inclusion criteria were patients with presumptive ICD-10 codes including "dizziness" or "vertigo". Patient demographics were compared using the χ2 test and Kruskal-Wallis test. Logistic regression analysis was performed to calculate disposition from ED (emergency admission or discharge) over the 3-year study period. The adjusted odds ratio (OR) and 95% confidence interval (CI) were calculated using multivariate analyses.

Results: During the 3-year study period, a total of 1,346,457 patients (462,773 in 2018, 468,697 in 2019, and 414,987 in 2020; P < 0.001), including 53,190 patients with dizziness (18,396 in 2018, 18,649 in 2019, and 16,145 in 2020; P = 0.058), were identified as having been transported to hospitals by ambulance in Osaka Prefecture. Dizziness and giddiness (R42) was the most common form of dizziness, in 27,075 cases (9,570 in 2018, 9,613 in 2019, and 7,892 in 2020; P < 0.001; Gender composition showed 10,483 males and 16,592 females.) Vestibular Neuronitis (H81.2) showed significant increase in 2020 compared to the two preceding years (91 in 2018, 119 in 2019, and 130 in 2020, P = 0.003; including 174 males and 167 females, respectively). Of the 53,190 patients with dizziness, 11,862 (22.3%; 4,323 males, 7,539 females) were admitted to hospital. The odds ratio (OR) for emergency admission for dizziness in 2020 during the COVID-19 pandemic was 0.98 (95% confidence interval (CI), 0.93- 1.03) with reference to 2018.

Conclusion: Patients with dizziness accounted approximately 4% of ED transportations, with about 20% requiring hospital admission, irrespective of the COVID-19 pandemic. Vestibular neuronitis was significantly increased in 2020.

Background: Idiopathic scoliosis (IS) is a structural spinal deformity that can affect the position of the head. One of the etiological hypotheses is that it can be caused by dysfunction of the vestibular system, which can cause abnormal perception of subjective visual vertical (SVV).

Objective: This study aimed to evaluate the differences in head position and its possible correlation with the perception of SVV in children with IS.

Methods: We examined 37 patients with IS and 37 healthy individuals. The position of the head was evaluated from digital photographs, where we compared the coronal head tilt and the coronal shoulder angle. Measurement of SVV perception was performed using the Bucket method.

Results: Coronal head tilt values were significantly different between the groups (median 2.3° [interquartile range 1.8-4.2] vs 1.3° [0.9-2.3], p = 0.001; patients vs. controls). There was a significant difference in SVV between the groups (2.33° [1.40-3.25] vs 0.50° [0.41-1.10], p < 0.001; patients vs controls). There was a correlation between the side of head tilt and the side of SVV in patients with IS (χ2 = 5.6, p = 0.02).

Conclusions: Patients with IS had a greater head tilt in the coronal plane and impaired SVV perception.

Background: The vestibular system provides a comprehensive estimate of self-motion in 3D space. Widely used to artificially stimulate the vestibular system, binaural-bipolar square-wave Galvanic Vestibular Stimulation (GVS) elicits a virtual sensation of roll rotation. Postural responses to GVS have been clearly delineated, however quantifying the perceived virtual rotation vector has not been fully realised.

Objective: We aimed to quantify the perceived virtual roll rotation vector elicited by GVS using a psychophysical approach on a 3D turntable.

Methods: Participants were placed supine on the 3D turntable and rotated around the naso-occipital axis while supine and received square-wave binaural-bipolar GVS or sham stimulation. GVS amplitudes and intensities were systematically manipulated. The turntable motion profile consisted of a velocity step of 20°/s2 until the trial velocity between 0-20°/s was reached, followed by a 1°/s ramp until the end of the trial. In a psychophysical adaptive staircase procedure, we systematically varied the roll velocity to identify the exact velocity that cancelled the perceived roll sensation induced by GVS.

Results: Participants perceived a virtual roll rotation towards the cathode of approximately 2°/s velocity for 1 mA GVS and 6°/s velocity for 2.5 mA GVS. The observed values were stable across repetitions.

Conclusions: Our results quantify for the first time the perceived virtual roll rotations induced by binaural-bipolar square-wave GVS. Importantly, estimates were based on perceptual judgements, in the absence of motor or postural responses and in a head orientation where the GVS-induced roll sensation did not interact with the perceived direction of gravity. This is an important step towards applications of GVS in different settings, including sensory substitution or Virtual Reality.

Background/objective: There exists limited information in the literature on dominant hand preference in relation with vHIT applications. The present study aimed to examine the relationship between the clinician's dominant use of right- or left-hand and vHIT results.

Methods: A Synapsys vHIT Ulmer device was used in the study. The tests were administered by 3 clinicians experienced in vHIT, 2 of whom were right-handed and 1 left-handed. The test was applied to the 94 participants three times, one week apart.

Results: In this study, the correlation between right-handed clinicians and left-handed clinicians was examined, and in all SCCs, namely RA, LA, RL, LL, RP and LP, a moderate positive significant correlation was found between right-handed1 and right-handed2, between right-handed1 and left-handed, and between right-handed2 and left-handed.

Conclusions: In this study, these findings suggested that measures were reliable across test sessions regardless of hand dominancy (right or left). Based on the vHIT results we obtained with three different right- or left-handed clinicians, the clinician should evaluate the results according to the dominant side.

Background: During a simulated coordinated turn in a gondola centrifuge, experienced pilots show a substantial inter-individual variability in visual measures of perceived roll tilt. Because of the centrifuge's small radius, the pattern of stimuli to the semicircular canals during acceleration of the centrifuge differs in certain respects from that of an aircraft entering a turn.

Objective: To explore whether these differences may be of significance for the pilot's roll- plane orientation and whether individual characteristics revealed in the centrifuge correspond to those during real flight.

Method: 8 fixed-wing air-force pilots were tested in a centrifuge and a high-performance aircraft. The centrifuge was accelerated to 2 G (gondola inclination 60°) within 10 s. The duration at 2 G was 6 minutes. Similar profiles were created in the aircraft. The subjective visual horizontal (SVH) was measured using an adjustable luminous line in darkness. Each pilot was tested on three occasions: centrifuge (2 runs), aircraft (2 turns), centrifuge (2 runs). For each 2-G exposure, initial and final SVH values were established via curve fitting.

Result: Despite a large inter-individual variability (±SD), group means were similar in the aircraft (initial: 43.0±20.6°; final: 22.5±14.8°) and centrifuge (initial: 40.6±17.0°; final: 20.5±16.0°). Further, individual peculiarities in response patterns were similar in the two conditions. For both the initial and final SVH tilt there was a high correlation between centrifuge and aircraft.

Conclusion: The correspondence between conditions suggests that the centrifuge is an adequate means for demonstrating the fundamental motion pattern of coordinated flight and also for establishing the individual pilot's ability to perceive an aircraft's roll attitude.Findings are discussed in connection with vestibular learning and the possibility of underlying differences between pilots in the keenness for semicircular canal and somatosensory cues.

Background: Rafael Lorente de Nó was a neuroscientist that worked alongside two of the giants of Medicine, the Nobel Prize winners Cajal and Bárány.

Objective: To describe the contributions of Lorente de Nó to vestibular neuroscience.

Methods: Detailed review of the publications of Lorente de Nó and analysis of the archives from Junta para Ampliación de Estudios e Investigaciones Científicas at Residencia de Estudiantes (Madrid, Spain), Casa de Salud Valdecilla at Hospital Universitario Marqués de Valdecilla (Santander, Spain), Becker Medical Library at Washington University (St. Louis, MO, USA), Rockefeller Archive Center (Sleepy Hollow, New York, NY, USA), Archivo Fernando de Castro (Madrid, Spain), Biblioteca Nacional de España (Madrid, Spain) and Legado Cajal at Instituto Cajal (Madrid, Spain). Most of this material is unpublished and includes over a hundred letters to or from Lorente.

Results: Lorente de Nó made a substantial contribution to our understanding of the vestibular system. Amongst these, he meticulously detailed the course of the vestibular nerve and its central projections. He described the vestibulo-ocular reflex as the consequence of an integration of the various nuclei and connections across the vestibular system, rather than a simple three-neuron arc. He also highlighted the role of the reticular formation in the generation of the fast phase of the nystagmus.

Conclusions: Lorente de Nó was a pioneer of modern neuro-otology, having made outstanding contributions to vestibular neuroscience, forging novel discoveries that still burn true today.

Background: During near-viewing, the vestibulo-ocular reflex (VOR) response/gain increases to compensate for the relatively larger translation of the eyes with respect to the target.

Objective: To review vergence-mediated gain increase (VMGI) testing methods stimuli and responses (latency and amplitude), peripheral/central pathways and clinical relevance.

Methods: The authors discuss publications listed in PUBMED since 1980 in the light of their own studies.

Results: The VMGI can be measured during rotational, linear and combined head accelerations. It has short-latency, non-compensatory amplitude, and relies on irregularly discharging peripheral afferents and their pathways. It is driven by a combination of perception, visual-context and internal modelling.

Conclusions: Currently, there are technical barriers that hinder VMGI measurement in the clinic. However, the VMGI may have diagnostic value, especially with regards to measuring otolith function. The VMGI also may have potential value in rehabilitation by providing insight about a patient's lesion and how to best tailor a rehabilitation program for them, that potentially includes VOR adaptation training during near-viewing.

Introduction: No reliable biometric measurement of vestibular involvement with migraine is currently available.

Objective: Measures of autonomic nervous system and postural responses could serve as quantifiable indicators of vestibular involvement with migraine.

Methods: A convenience sample of 22 young healthy adults (34±9 years old) and 23 young adults (34±8 years old) diagnosed with vestibular migraine (VM) participated. A rod and frame test and clinical outcome measures of dizziness and mobility were administered. Participants stood on foam while viewing two dynamic virtual environments. Trunk acceleration in three planes and electrodermal activity (EDA) were assessed with wearable sensors. Linear mixed models were used to examine magnitude and smoothness of trunk acceleration and tonic and phasic EDA. A Welch's t-test and associations between measures were assessed with a Pearson Correlation Coefficient. Effect sizes of group mean differences were calculated using Cohen's d.

Results: Visual dependence was present in 83% of the VM population. Individuals with VM exhibited lower baseline EDA (t(4.17) = -7.2, p = 0.001) and greater normalized trunk accelerations in the vertical (t(42.5) = 2.861, p = 0.006) and medial (t(46.6) = 2.65, p = 0.01) planes than healthy participants. Tonic EDA activity increased significantly across the period of the trial (F (1,417) = 23.31, p = 0.001) in the VM group. Significant associations appeared between vertical trunk acceleration and EDA, Dizziness Handicap Inventory, and Activities of Balance Confidence tools.

Conclusions: Higher tonic EDA activity in healthy adults results in more accurate postural reactions. Results support the supposition that EDA activity and postural acceleration are significantly different between VM and healthy individuals when accommodating for postural instability and visual-vestibular conflict.

Background: Vestibular rehabilitation therapy (VRT) is effective for most patients with dizziness and imbalance. Home exercise programs are widely used. It is unknown, however, how specific the instructions for exercises have to be.

Objective: To evaluate the effects of expert assessment and instructions in a booklet-based home VRT program for patients with chronic dizziness.

Methods: Randomized controlled study on 74 participants with disabling dizziness for >3 months. All study participants received a booklet-based VRT for training at home. Participants were prescribed 20 minutes of exercise, twice a day. The intervention group (n = 37) received specific instructions (expert physiotherapist). The control group (n = 37) practiced without specific instructions. Primary outcome was the total score of the Dizziness Handicap Inventory (DHI-G). All outcomes were assessed at baseline, after 4 weeks, and at follow up 4 weeks later.

Results: Both groups improved (DHI-G 43.94±18.89 at inclusion to 33.06±19.67 at follow-up in controls and 42.82±16.60 to 22.65±19.12 in the intervention group). The intervention group, however, improved more (p = 0.014).

Conclusions: We show a significant effect of expert physiotherapy guidance in home-based VRT. This strengthens the role of the physiotherapist in VRT: Tailored, personalized instructions are needed to get the best effect of VRT.