Journal of Vestibular Research-Equilibrium & Orientation最新文献

Background: The video head impulse test (vHIT) is a common assessment of semicircular canal function during high-speed impulses. Reliability of the vHIT for assessing vertical semicircular canals is uncertain. Vertical head impulses require a complex head movement, making it difficult to isolate a single semicircular canal and interpret resulting eye rotations.

Objective: The purpose of this study was to provide descriptive head kinematics and vestibular stimuli during vertical plane impulses to ultimately improve impulse delivery and interpretation of vHIT results for vertical semicircular canals.

Methods: Six participants received right anterior (RA) and left posterior (LP) semicircular canal impulses. Linear displacements, rotational displacements, and rotational velocities of the head were measured. Peak velocities in semicircular canal planes and peak-to-peak gravitoinertial accelerations at the otolith organs were derived from head kinematics.

Results: The largest rotational velocities occurred in the target semicircular canal plane, with non-negligible velocities occurring in non-target planes. Larger vertical displacements and accelerations occurred on the right side of the head compared to the left for RA and LP impulses.

Conclusions: These results provide a foundation for designing protocols to optimize stimulation applied to a singular vertical semicircular canal and for interpreting results from the vHIT for vertical semicircular canals.

Background: The reproducibility of the effective intensity of noisy galvanic vestibular stimulation (nGVS) to improve postural stability is not well known.

Objective: We aimed to investigate inter-day and intra-day variations in effective intensity in patients with bilateral vestibulopathy (BVP).

Methods: Thirteen BVP patients were measured for center-of-pressure movements in the standing posture at five time points: morning of the first test day, morning and evening of the second test day, and morning and evening of the third test day. The mean velocity, the envelopment area, and the root mean square were measured in the eyes-closed condition for 30 s during nGVS application ranging from 0 to 1000μA. The effective intensity was defined as the intensity at which all the three parameters measured during the stimulation were simultaneously smaller than the values at baseline (0μA).

Results: Seven of the 13 patients had a common effective intensity throughout the three test days. Six patients on the second test day and five patients on the third test day had no common effective intensity between morning and evening.

Conclusions: The effective intensity of nGVS changes depending on the time during the day as well as between the days.

Background: Video head impulse test (vHIT) and videonystagmography (VNG) provide significant benefits in evaluating benign paroxysmal positional vertigo (BPPV) and determining the semicircular canal localization of the otoconia.

Objective: This study aimed to investigate the relationship between vestibular-ocular reflex (VOR) gains measured via vHIT and the slow-phase velocity (SPV) of nystagmus in patients with the posterior semicircular canal (PSCC)-BPPV.

Methods: Sixty-two patients were included in this study and divided into the study (n = 32, patients with isolated PSCC-BPPV) and control (n = 30, age- and sex-matched healthy individuals) groups. While VOR gains were measured with vHIT in both groups and compared between groups, the SPV values of nystagmus observed during the Dix-Hallpike maneuver in the study group were recorded using VNG and compared with the VOR gains of the study group.

Results: There were significant differences in posterior canal VOR gains between the study and control groups (p < 0.001 and p < 0.01, respectively). Although the affected PSCC had decreased VOR gains versus the control group, it was still within the normal range. However, there was no significant relationship between the VOR gains of the affected PSCC and the SPV of the nystagmus.

Conclusions: vHIT can help detect semicircular canal dysfunction in patients with PSCC-BPPV. The SPV values of nystagmus on VNG during the Dix-Hallpike maneuver do not correlate with the level of VOR gain.

Background: Unilateral vestibular hypofunction (UVH) may lead to modifications on metabolism and body composition. Vestibular rehabilitation (VR) demonstrated its effectiveness in ameliorating balance function and several other daily-living aspects.

Objectives: The aim of this study was to evaluate metabolic composition, by means of bioelectrical impedance analysis (BIA) and daily activity, with the use of a wrist-worn movement tracker, in UVH participants before and after VR, and to compare data with a healthy control group (CG) of adults.

Methods: 46 UVH and 60 CG participants underwent otoneurological testing, self-report and performance questionnaires, BIA, and wore a device tracking daily movement and energy expenditure for one full day; this was performed before and after VR.

Results: UVH participants demonstrated a significant (p = 0.008) increase in muscle mass after VR, and, when compared to CG, no differences were present with respect to visceral fat and muscle mass. UVH adults reported a significant increase in energy expenditure spent in movement (p = 0.008) and during the day (p = 0.009), daily number of strides (p = 0.009) and calories spent in sweeping (p = 0.009) and stairing (p = 0.008).

Conclusions: Results from this study show that VR provided an improvement of metabolic function and body composition of people with UVH, possibly by contrasting structural modifications in neural pathways stemming from the vestibular nuclei and connected to autonomous function.

Aim: To comprehensively evaluate the dynamic change of vestibular function during long-term follow-up of vestibular neuritis, as well as the co-relationship with the outcomes of vestibular neuritis (VN), which provides the recommendations for vestibular function tests during the course of VN.

Methods: A prospective cohort study was conducted on 16 patients with acute VN. Caloric test, vHIT, rotatory chair tests, VEMP, dizziness handicap inventory (DHI) score, and dynamic dizzy scales (VAS-DD) was first performed within 7 days of neuritis onset, which were further re-evaluated during the 6-12 months of follow-up. The dynamic changes on multiple objective vestibular examinations were analyzed during the acute and recovery stage of VN. We further evaluated the co-relationship between the vestibular dysfunction scales and the prognosis of VN.

Results: In more than 6 months of follow-up, 44% of the ultralow frequency, 94% of the low-to-mid frequency, and 44% of the high-frequency function of the horizontal semicircular canal returned to normal (p < 0.05). The change degree in symmetry of the rotatory chair test was correlated with the gain of the horizontal semicircular canal on the vHIT and the unilateral weakness (UW) value on the caloric test (p < 0.05). The change in DHI score was correlated with the phase; change in VAS-DD level correlated with the symmetry and TC of the rotatory chair test at VN recovery stage (p < 0.05). There was no significant correlation between the change in DHI score or change in VAS-DD and the degree of vestibular function recovery (p > 0.05).

Conclusion: In general, vestibular function improved during the course of VN. The rotatory chair test can be used to evaluate the overall function of the vestibular system and the compensatory state in patients with VN.

Objective/background: Though sleep problems (apnea, insomnia) and related daytime symptoms (fatigue, anxiety, depression) have been associated with vestibular problems (falls, dizziness), it is not well known which particular sleep features relate to vestibular problems. We thus assessed symptoms of vestibular problems in patients visiting a sleep clinic and evaluated how they were associated with objective sleep parameters derived from polysomnography and relevant daytime symptoms.

Patients/methods: The polysomnography data of thirty-one patients (61% female, between 20 and 79 years of age) who were referred for clinical sleep assessment was collated with subjective measures of symptoms linked to vestibular problems (rated on the Situational Characteristics Questionnaire), as well as fatigue, anxiety and depression symptoms. Multiple linear regression was used to identify factors associated with vestibular symptoms, including analyses adjusted for age, sex, medication use and total sleep time.

Results: A higher percentage of REM sleep and more severe anxiety symptoms were independently associated with more severe vestibular symptoms, which survived adjusted analyses. Other sleep stages, as well as as sleep efficiency, apnea-hypopnea index and oxygen saturation were not significantly related to vestibular symptoms.

Conclusions: These results point at vestibular symptoms as possible important and overlooked correlates of variations in sleep architecture in individuals with sleep complaints. Though replication is needed to confirm findings from this limited sample, the results highlight the importance of assessing vestibular symptoms in people with sleep complaints. In particular, further investigations will need to address the potential implication of REM sleep for vestibular functions and the directionality of this relation.

Background: Cognitive deficits have been defined in patients with bilateral and unilateral vestibular loss.

Objective: To investigate cognitive functions in patients with episodic vestibular disorders.

Methods: Nineteen patients with Meniere's disease (MD), 19 patients with vestibular migraine (VM) and 21 age and education matched healthy controls were studied. Mini Mental State Examination assessing global mental status, Reading Span Test and the Stroop Test evaluating working memory, cognitive processing, reading comprehension and attention, Trail Making Test and Benton's Judgment of Line Orientation Test investigating visual processing, visuospatial skills, processing speed were used. Beck depression and anxiety inventories were given to evaluate the emotional status.

Results: Cognitive test results of the MD and VM patients were not significantly different from the healthy controls (p > 0.05) as well as Beck depression scores (p = 0.14). Beck anxiety scores showed significant difference (p = 0.003). VM patients had significantly higher scores than the healthy controls (p = 0.002) on pairwise comparisons. The scores of the MD patients did not reach statistical significance (p = 0.15).

Conclusion: Episodic vestibular disorders like MD and VM without inter-ictal vestibular deficits do not seem to be associated with cognitive impairment. Patients with VM have significantly higher anxiety scores than the healthy controls and MD patients.

Background: The management of dizziness and vertigo can be challenging in the emergency department (ED). It is important to rapidly diagnose vertebrobasilar stroke (VBS), as therapeutic options such as thrombolysis and anticoagulation require prompt decisions.

Objective: This study aims to assess the rate of misdiagnosis in patients with dizziness caused by VBS in the ED.

Methods and results: The cohort was comprised of 66 patients with a mean age 56 years; 48% were women and 52% men. Among dizzy patients, 14% had VBS. We used Cohen's kappa test to quantify the agreement between two raters -namely, emergency physicians and neurologists -regarding the causes of dizziness in the ED. The Kappa value was 0.27 regarding the final diagnosis of central vertigo disorders and VBS, thus showing the low agreement. We used the χi2 test to show the association between the presence of two or more cardiovascular risk factors and admission to the stroke unit (p = 0.015).

Conclusion: There is a substantial rate of misdiagnosis in patients with dizziness caused by VBS in the ED. To reduce the number of missing diagnoses of VBS in the future, there is a need to train emergency physicians in neurovestibular examinations, including the HINTS examination for acute vestibular syndrome (AVS) and the Dix-Hallpike (DH) maneuver for episodic vestibular syndrome. Using video head impulse test could help reduce the rate of misdiagnosis of VBS in the ED.