Unilateral Vestibulopathy Research Articles

The Correlation Between Fear Avoidance Beliefs and Physical Activity in Unilateral Vestibulopathies

The Correlation Between Fear Avoidance Beliefs and Physical Activity in Unilateral Vestibulopathies

Does dimenhydrinate delay recovery of vestibular ocular reflex in acute unilateral vestibulopathy? A retrospective comparative study

Does dimenhydrinate delay recovery of vestibular ocular reflex in acute unilateral vestibulopathy? A retrospective comparative study

Predictors of Chronic Dizziness in Acute Unilateral Vestibulopathy: A Longitudinal Prospective Cohort Study.

Chronic dizziness after acute unilateral vestibulopathy (AUVP) causes significant social and economic burdens. This study aims to identify predictors of chronic dizziness. Prospective, longitudinal cohort study. ENT departments from secondary and tertiary hospitals. Participants meeting the Barany Society's diagnostic criteria for AUVP were included. Evaluations occurred within 0 to 21 days (T1), and at 4 (T2) and 10 weeks (T3) postonset. The primary outcome measure was the Dizziness Handicap Inventory (DHI) at 6 months, with a score >30 indicating chronic dizziness. Five clusters of predictors were assessed at T1-3: central vestibular compensation, visual dependence, movement exposure, psychological factors, and balance performance. Separate linear regression models for T1, T2, and T3 were constructed to explain the variability in the 6-month DHI score. Receiver operating characteristics analyses were conducted to predict chronic dizziness. From June 2021 to January 2024, 103 participants (55.2 ± 16.6 years old, 49 women) were included. The regression models explained the variability in the 6-month DHI score by 33.0% at T1, 47.6% at T2, and 64.0% at T3 (P < .001), including psychological factors (T1, T2, T3), visual dependence (T2, T3), and static balance performance (T3). Cutoff values for the Vestibular Activities Avoidance Instrument (23/54), Visual Vertigo Analog Scale (33.5/100), and Hospital Anxiety and Depression Scale-Anxiety (7.5/21) at 10 weeks postonset predicted chronic dizziness. Higher psychological burden, increased visual dependence, and poorer static balance performance were associated with chronic dizziness. Cutoff values were determined to identify individuals with AUVP at risk for chronic dizziness.

Unreliable association between self-reported sense of direction and peripheral vestibular function.

Uni- or bilateral peripheralvestibular impairment causes objective spatial orientation deficits, which can be measured using pen-and-paper-tests or sensorimotor tasks (navigation or pointing). For patients' subjective orientation abilities, questionnaires are commonly used (e.g., Santa Barbara sense of direction scale [SBSODS]). However, the relationship between subjective assessment of spatial skills and objective vestibular function has only been scarcely investigated. A total of 177 patients (mean age 57.86±17.53 years, 90 females) who presented in our tertiary Center for Vertigo and Balance Disorders underwent neuro-otological examinations, including bithermal water calorics, video head impulse test (vHIT), and testing of the subjective visual vertical (SVV), and filled out the SBSODS (German version). Correlation analyses and linear multiple regression model analyses were performed between vestibular test results and self-assessment scores. Additionally, groupwise vestibular function for patients with low, average, and high self-report scores was analyzed. Forty-two patients fulfilled the diagnostic criteria for bilateral vestibulopathy, 93 for chronic unilateral vestibulopathy (68 unilateral caloric hypofunction and 25 isolated horizontal vestibulo-ocular reflex deficits), and 42 patients had normal vestibular test results. SBSODS scores showed clear sex differences with higher subjective skill levels in males (mean score males: 4.94±0.99, females 4.40±0.94; Student's t-test: t-3.78, p<.001***). No stable correlation between objective vestibular function and subjective sense of spatial orientation was found. A multiple linear regression model could not reliably explain the self-reported variance. The three patient groups with low, average, and high self-assessment-scores showed no significant differences of vestibular function. Self-reported assessment of spatial orientation does not robustly correlate with objective peripheral vestibular function. Therefore, other methods of measuring spatial skills in real-world and virtual environments are required to disclose orientation deficits due to vestibular hypofunction.

Positional End-Point Nystagmus in Patients with Diagnosis of Acute Unilateral Vestibulopathy.

Recently, end-point nystagmus, traditionally observed in an upright position, has been identified in the Dix-Hallpike position among healthy subjects, suggesting a physiological origin.However, its characteristics in individuals with vestibular hypofunction remain unexplored. To elucidate the impact of vestibular hypofunction on the characteristics of positional end-point nystagmus. Thirty-one patients diagnosed with acute unilateral vestibulopathy according to Bárány Society criteria were selected. A video head impulse test was conducted in all participants, followed by McClure and Dix-Hallpike maneuvers with and without gaze fixation, and with the initial position of the eye in the straight-ahead position or in the horizontal end-point position. Nystagmus direction, sense, latency, slow-phase velocity, and duration were recorded. The relationship between these characteristics and video head impulse test values was analyzed. Positional end-point nystagmus was observed in 92.6% of subjects with vestibular hypofunction, significantly more than in healthy individuals. Nystagmus direction varied depending on the performed positional test and on the vestibulo-ocular reflex gains. Gaze occlusion and the initial horizontal end-point position increased its frequency. Vestibular hypofunction influences the manifestation of positional end-point nystagmus. Recognizing this nystagmus can aid in resolving diagnostic uncertainties and preventing the misdiagnosis of benign paroxysmal positional vertigo in subjects with acute unilateral vestibulopathy.

Four-hour-delayed 3D-FLAIR MRIs in patients with acute unilateral peripheral vestibulopathy.

Conventionally, MRI aids in differentiating acute unilateral peripheral vestibulopathy/vestibular neuritis (AUPV/VN) from mimickers. Meanwhile, the diagnostic utility of MRIs dedicated to the inner ear remains to be elucidated for diagnosing AUPV/VN. We prospectively recruited 53 patients with AUPV/VN (mean age ± SD = 60 ± 15 years, 29 men). Initial MRIs were performed with a standard protocol, and an additional axial 3D-fluid-attenuated inversion recovery (3D-FLAIR) sequence was obtained 4 h after intravenous injection of gadoterate meglumine. Abnormal enhancement was defined as a signal intensity that exceeded the mean + 2SD value on the healthy side. The findings of neurotologic evaluation and MRIs were compared. Overall, the inter-rater agreement for gadolinium enhancement was 0.886 (Cohen's kappa coefficient). Enhancement was observed in 26 patients (49%), most frequently in the vestibule (n = 20), followed by the anterior (n = 12), horizontal (HC, n = 8), posterior canal (n = 5), and superior (n = 3) and inferior (n = 1) vestibular nerves. In multivariable logistic regression analysis, the enhancement was associated with decreased HC gain in video head-impulse tests (p = 0.036), increased interaural difference in ocular vestibular-evoked myogenic potentials (p = 0.001), and a longer onset-to-MRI time span (p = 0.024). The sensitivity and specificity were 92.3% and 81.5%, respectively, with an area under the curve of 0.90 for predicting gadolinium enhancement. Robust gadolinium enhancement was observed on 4-hour-delayed 3D-FLAIR images in nearly half of the patients with AUPV/VN, with a good correlation with the results of neurotologic evaluation. The positivity may be determined by the extent of vestibular deficit, timing of imaging acquisition, and possibly by the underlying etiology causing AUPV/VN. MRIs may aid in delineating the involved structures in AUPV/VN.

Association of Peripheral Vestibular Disorder with Diabetes: A Population-Based Study.

This study aimed to investigate the association of peripheral vestibular disorders with type 1 and type 2 diabetes using a population-based dataset. The data for this study were obtained from Taiwan's Longitudinal Health Insurance Database 2010. The sample consisted of 150,916 patients who were newly diagnosed with peripheral vestibular disorders as cases and 452,748 propensity-score-matching controls without peripheral vestibular disorders. We utilized multivariate logistic regression models to quantitatively evaluate the association between peripheral vestibular disorders and diabetes while considering factors such as sex, age, geographic location, monthly income, urbanization level of the patient's residence, coronary heart disease, hypertension, and hyperlipidemia. The chi-squared test indicates that diabetes was more common in the peripheral vestibular disorder group compared to controls (20.6% vs. 15.1%, p < 0.001). Of all sampled patients, the adjusted odds ratio for diabetes was 1.597 (95% CI = 1.570~1.623) for those with peripheral vestibular disorders when compared to controls, while patients with Ménière's disease, benign paroxysmal positional vertigo, unilateral vestibulopathy, and other peripheral vestibular disorders had respective adjusted odds ratios of diabetes at 1.566 (95% CI = 1.498~1.638), 1.677 (95% CI = 1.603~1.755), 1.592 (95% CI = 1.504~1.685), and 1.588 (95% CI = l.555~1.621) in comparison to controls. Our research has revealed an association between diabetes and an increased susceptibility to peripheral vestibular disorders.

Systematic Review and Meta-Analysis of the Diagnostic Accuracy of a Graded Gait and Truncal Instability Rating in Acutely Dizzy and Ataxic Patients.

In patients presenting with acute prolonged vertigo and/or gait imbalance, the HINTS [Head-Impulse, Nystagmus, Test-of-Skew] are very valuable. However, their application may be limited by lack of training and absence of vertigo/nystagmus. Alternatively, a graded gait/truncal-instability (GTI, grade 0-3) rating may be applied. We performed a systematic search (MEDLINE/Embase) to identify studies reporting on the diagnostic accuracy of bedside examinations in adults with acute vestibular syndrome. Diagnostic test properties were calculated for findings using a random-effects model. Results were stratified by GTI-rating used. We identified 6515 articles and included 18 studies (n = 1025 patients). Ischemic strokes (n = 665) and acute unilateral vestibulopathy (n = 306) were most frequent. Grade 2/3 GTI had moderate sensitivity (70.8% [95% confidence-interval (CI) = 59.3-82.3%]) and specificity (82.7 [71.6-93.8%]) for predicting a central cause, whereas grade 3 GTI had a lower sensitivity (44.0% [34.3-53.7%] and higher specificity (99.1% [98.0-100.0%]). In comparison, diagnostic accuracy of HINTS (sensitivity = 96.8% [94.8-98.8%]; specificity = 97.6% [95.3-99.9%]) was higher. When combining central nystagmus-patterns and grade 2/3 GTI, sensitivity was increased to 76.4% [71.3-81.6%] and specificity to 90.3% [84.3-96.3%], however, no random effects model could be used. Sensitivity was higher in studies using the GTI rating (grade 2/3) by Lee (2006) compared to the approach by Moon (2009) (73.8% [69.0-78.0%] vs. 57.4% [49.5-64.9%], p = 0.001). In comparison to HINTS, the diagnostic accuracy of GTI is inferior. When combined with central nystagmus-patterns, diagnostic accuracy could be improved based on preliminary findings. GTI can be readily applied in the ED-setting and also in patients with acute imbalance syndrome.

Asymmetry of the Subjective Visual Vertical in Patients With Unilateral Peripheral Vestibular Deficit.

Perception of verticality is clinically assessed using the subjective visual vertical (SVV), a test of the otolith system that consists of aligning a bar on the gravitational vertical in darkness. Patients with acute unilateral vestibulopathy (AUVP) show a systematic SVV bias toward the affected side, whichever the side of line orientation. Whether SVV estimates are symmetrical has not been investigated. This study included 10 patients with AUVP (vestibular neuritis) and 10 with BPPV (posterior semicircular canal). SVV measurements were made at two preset angles of line orientation (15° and 30°) toward the ipsilateral and contralateral sides, relative to the affected side. The results showed asymmetrical SVV estimates in the AUVP group, with significantly greater SVV errors for ipsilateral than contralateral line orientation, as well as for the preset angle of 30° compared to 15°. SVV estimates were significantly lower in patients with BPPV who also exhibited SVV asymmetry. SVV estimates remained unchanged just after the maneuver and were normalized some days later or after supplementary maneuvers. SVV asymmetry should be routinely considered in the clinic. We recommend individually assessing ipsilateral and contralateral SVV and using at least two preset angles. This allows for a better assessment and diagnosis of otolith organ imbalance that can trigger chronic instability and dizziness. The contribution of neck afferents related to head position in space seems to be the main source of SVV asymmetry.

Accuracy of the Bedside Examination in Patients With Suspected Acute Unilateral Peripheral Vestibulopathy.

Acute unilateral peripheral vestibulopathy (AUPVP) is a frequent form of peripheral vestibular vertigo characterized by unilateral vestibular organ dysfunction. Diagnostic challenges in anamnesis and bedside examination can lead to potential misdiagnoses. This study investigated the sensitivity of bedside examinations in diagnosing AUPVP. This retrospective analysis examined 136 AUPVP inpatients at a level 3 university hospital between 2017 and 2019. Demographic data and bedside test results were collected. Instrumental otoneurological tests included caloric testing and video head impulse test (HIT). The sensitivity of each bedside parameter was computed based on the instrumental diagnostics, and statistical analyses were performed. The study included 76 men and 60 women, with a mean age of 59.2 years. Spontaneous nystagmus exhibited a sensitivity of 92%, whereas the absence of skew deviation was identified with a sensitivity of 98%. Abnormal bedside HIT showed a sensitivity of 87%. The combined HINTS (HIT, nystagmus, and test of skew) had a sensitivity of 83%. The Romberg test and Fukuda test demonstrated sensitivities of 26% and 48%, respectively. The sensitivity of bedside tests varied from 26% to 98%. This aligns with previous literature, highlighting the challenge of differentiating AUPVP from vestibular pseudoneuritis solely through bedside examination. Although the tests excel in excluding central causes, they are insufficient for diagnosing AUPVP with certainty. In addition, the bedside examination sensitivities vary widely, and early radiological imaging can be misleading. Therefore, this study underlines the necessity of prompt otoneurological testing for accurate exclusion of vestibular pseudoneuritis and thus improve patient outcomes.

Altered thalamus functional connectivity in patients with acute unilateral vestibulopathy: a resting-state fMRI study.

Acute unilateral vestibulopathy (AUVP) is the second leading cause of peripheral vestibular vertigo. Full recovery of AUVP is related to sufficient central vestibular compensation. It has been confirmed that the vestibular nucleus and vestibular cortex are involved in the process of vestibular compensatory in AUVP patients. However, few studies have focused on the functional compensation of thalamus in patients with AUVP. This study aimed to explore the alterations of resting-state functional connectivity (FC) focused on thalamus using functional magnetic resonance imaging (fMRI) in AUVP patients. Data of 3D-T1 and resting-state fMRI were collected from 40 AUVP patients and 35 healthy controls (HC). Seeds-based (bilateral thalamus) FC was analyzed to investigate the changes in FC between the two groups. Furthermore, we evaluated the associations between altered thalamus FC and clinical features in AUVP patients using Pearson's partial correlation. Compared with HC, AUVP patients showed decreased FC between bilateral thalamus and left insula. We also observed decreased FC between right thalamus and left supramarginal gyrus. Additionally, we found increased FC between left thalamus and right postcentral gyrus (PCG), as well as increased FC between right thalamus and regions of bilateral PCG, right middle frontal gyrus and right middle occipital gyrus in AUVP patients. Furthermore, the FC between left thalamus and left insula was negatively correlated with values of canal paresis in patients with AUVP (p = 0.010, r = -0.434). Our results provided first evidence for the decreased thalamo-vestibular cortex pathway, as well as increased thalamo-somatosensory and thalamo-visual cortex pathway in AUVP patients. These findings help us better understand the underlying mechanisms of central dynamic compensatory following an acute unilateral peripheral vestibular damage.

High-Frequency Vestibular Function Is Vulnerable to Presbyvestibulopathy.

In 2019, mild vestibular function deficiency in elder populations was defined as presbyvestibulopathy (PVP) by the Classification Committee of the Bárány Society. The diagnostic criteria include tests for low-, mid-, and high-frequency vestibular function, represented by caloric testing, rotary chair testing, and head impulse testing, respectively. However, there is still a lack of large-scale reports supporting the relationship between vestibular function tests (VFTs) and aging. In this study, we evaluated whether each test is correlated with aging in the elderly population aged over 50. This study retrospectively enrolled 1043 subjects from a single university hospital database after excluding those with unilateral and bilateral vestibulopathy, central dizziness, and acute dizziness. Enrolled subjects had caloric canal paresis <20%, vHIT lateral canal gain >0.6, vHIT interaural difference <0.3, and age >50 years old. Significant negative correlations with age were identified in the vHIT (p < 0.001) and rotary chair test (RCT) 1.0 Hz gain (p = 0.030). However, the caloric test (p = 0.739 and 0.745 on the left and right sides, respectively) and RCT 0.12 Hz gain (p = 0.298) did not show a significant correlation with age. A total of 4.83% of subjects aged 70 years or older showed sub-normal vHIT gain that met the criteria of PVP, whereas only 0.50% of subjects aged 60 to 69 did. The prevalence of sub-normal caloric test results, however, was not significantly different between the two age groups (21.55% in the 60-69 age group and 26.59% in the >70 age group). The high-frequency range vestibular function seems vulnerable to aging, and this is more discernible at age >70 years. The weak correlation between age and low-frequency vestibular function tests, such as the caloric test and low-frequency rotary chair testing, suggests the need to revisit the diagnostic criteria for PVP.

Full-body kinematics and head stabilisation strategies during walking in patients with chronic unilateral and bilateral vestibulopathy

Chronic imbalance is a frequent and limiting symptom of patients with chronic unilateral and bilateral vestibulopathy. A full-body kinematic analysis of the movement of patients with vestibulopathy would provide a better understanding of the impact of the pathology on dynamic tasks such as walking. Therefore, this study aimed to investigate the global body movement during walking, its variability (assessed with the GaitSD), and the strategies to stabilise the head (assessed with the head Anchoring Index). The full-body motion capture data of 10 patients with bilateral vestibulopathy (BV), 10 patients with unilateral vestibulopathy (UV), and 10 healthy subjects (HS) walking at several speeds (slow, comfortable, and fast) were analysed in this prospective cohort study. We observed only a few significant differences between groups in parts of the gait cycle (shoulder abduction–adduction, pelvis rotation, and hip flexion–extension) during the analysis of kinematic curves. Only BV patients had significantly higher gait variability (GaitSD) for all three walking speeds. Head stabilisation strategies depended on the plan of motion and walking speed condition, but BV and UV patients tended to stabilise their head in relation to the trunk and HS tended to stabilise their head in space. These results suggest that GaitSD could be a relevant biomarker of chronic instability in BV and that the head Anchoring Index tends to confirm clinical observations of abnormal head-trunk dynamics in patients with vestibulopathy while walking.

Multifrekvenční testování pacientů po akutním izolovaném vestibulárním deficitu

Summary Introduction: Acute unilateral vestibulopathy (AUVP) is defined as an acute peripheral vestibular syndrome without evidence of central neurological or audiological symptoms. Currently, there is no uniform instrumental testing protocol for the diagnosis and follow-up of patients with AUVP. Vestibular tests provide information in different frequency bands of the vestibuloocular reflex (VOR); therefore, the aim of our study is to evaluate the contribution of multifrequency VOR testing in the evaluation of patients with AUVP. Methods: 22 patients (9 females and 13 males) with a diagnosis of AUVP were prospectively examined. Multifrequency testing included spontaneous nystagmus with visual fixation cancellation (SPN), Head Shaking Test (HST), bithermal air caloric test, and video Head Impulse Test (vHIT). The first examination was performed within one week of AUVP; follow-up examinations were performed 3 and 6 months apart. On the third examination, the Dizziness handicap inventory (DHI) questionnaire was completed. Results: The rate of the slow component of spontaneous and induced nystagmus during HST and the values of unilateral weakness (UW) during caloric testing decreased during follow-up with a statistically significant difference (P &lt;0.05) between both the first and second and between the second and third examinations. On vHIT, there was a statistically significant increase in the gains of individual channels during follow-up. Dissociation of vHIT and caloric test results was found in 22.73% of patients on the second and 18.18% of patients on the third examination. There was a statistically significant difference in the changes in test results of patients with different DHI. Conclusion: Multifrequency VOR testing provides a comprehensive overview of the status of vestibular function, recovery dynamics, and clinical impact of residual vestibular dysfunction after AUVP. Key words acute unilateral vestibulopathy – vestibuloocular reflex – video Head Impulse Test – caloric test – spontaneous nystagmus – Head Shaking Test

Evolution of Hyperventilation-Induced Nystagmus in Acute Unilateral Vestibulopathy-Interpretative Model and Etiopathogenetic Hypotheses.

Hyperventilation induces metabolic changes that can elicit nystagmus (hyperventilation-induced nystagmus, HVIN) in various vestibular disorders, revealing vestibular imbalance and bringing out central or peripheral asymmetries. In acute unilateral vestibulopathy (AUVP, namely vestibular neuritis), hyperventilation can induce different patterns of nystagmus (excitatory, inhibitory, or negative), disclosing or modifying existing static vestibular asymmetries through its ability to invalidate compensation or increase peripheral excitability. In this context, we followed the evolutionary stages of HVIN in AUVP across 35 consecutive patients, with the goal of assessing alterations in the oculomotor pattern caused by hyperventilation over time. In the acute phase, the incidence of the excitatory pattern (and the strongly excitatory one, consisting of a reversal nystagmus evoked by hyperventilation) was significantly higher compared to the inhibitory pattern; then, a progressive reduction in the incidence of the excitatory pattern and a concomitant gradual increase in the incidence of the inhibitory one were observed in the follow-up period. Assuming the role of the ephaptic effect and the transient loss of vestibular compensation as opposing mechanisms, i.e., excitatory and inhibitory, respectively, the oculomotor pattern evoked by hyperventilation is the result of the interaction of these two factors. The data obtained allowed us to hypothesize an interpretative model regarding the pathogenetic aspects of responses evoked by hyperventilation and the etiologies of the disease: according to our hypotheses, the excitatory pattern implies a neuritic (viral) form of AUVP; instead, the inhibitory (and negative) one can be an expression of both the neuritic (viral) and vascular forms of the disease.

The vestibular symptomatology of Machado-Joseph Disease.

Machado Joseph Disease (MJD) is an autosomal dominant neurodegenerative disease. In previous studies, we described significant bilateral horizontal Vestibulo-Ocular Reflex (VOR) deficit within this population without any reference to the presence of vestibular symptomatology. To evaluate whether, beyond cerebellar ataxia complaints, MJD patients have typical vestibular symptomatology corresponding to the accepted diagnostic criteria of Bilateral Vestibulopathy (BVP) according to the definition of the International Barany Society of Neuro-Otology. Twenty-one MJD, 12 clinically stable chronic Unilateral Vestibulopathy (UVP), 15 clinically stable chronic BVP, and 22 healthy Controls underwent the video Head Impulse Test (vHIT) evaluating VOR gain and filled out the following questionnaires related to vestibular symptomatology: The Dizziness Handicap Inventory (DHI), the Activities-specific Balance Confidence Scale (ABC), the Vertigo Visual Scale (VVS) and the Beck Anxiety Inventory (BAI). The MJD group demonstrated significant bilateral vestibular impairment with horizontal gain less than 0.6 in 71% of patients (0.54±0.17). Similar to UVP and BVP, MJD patients reported a significantly higher level of symptoms than Controls in the DHI, ABC, VVS, and BAI questionnaires. MJD demonstrated significant VOR impairment and clinical symptoms typical of BVP. We suggest that in a future version of the International Classification of Vestibular Disorders (ICVD), MJD should be categorized under a separate section of central vestibulopathy with the heading of bilateral vestibulopathy. The present findings are of importance regarding the clinical diagnosis process and possible treatment based on vestibular rehabilitation.

Altered Functional Connectivity of the Multisensory Vestibular Cortex in Patients with Chronic Unilateral Vestibulopathy.

Background: Chronic unilateral vestibulopathy (CUVP) is a common chronic vestibular syndrome; the mechanisms of central vestibular compensation in CUVP are rarely studied. Methods: This study analyzed the data of 18 patients with CUVP and 18 healthy controls (HCs) and used seed-based functional connectivity (FC) and voxel-mirrored homotopic connectivity (VMHC) analyses to explore the FC alterations. Results: Compared with HCs, patients with CUVP showed decreased FC between the left dorsolateral superior frontal gyrus and the right hippocampus; the left middle frontal gyrus and the right posterior cingulate gyrus, the right hippocampus, the right parahippocampal gyrus. There is also a reduction in FC betweenthe left and right insula. There was enhanced FC between the left supplementary motor area (SMA) and the bilateral superior occipital gyrus, the left hippocampus and the left posterior cingulate gyrus, as wellas a the left middle temporal gyrus (p = 0.03). Additionally,VMHC was decreased betweenthe bilateral medial superior frontal gyrus, the bilateral precentral gyrus, and the bilateral postcentral gyrus (p = 0.001). The zVMHC values in the bilateral superior frontal gyrus and the precentral gyrus were both negatively corrected with the Dizziness Handicap Inventory (DHI) score.wellas Conclusions: Altered FC in regions of bilateral multisensory vestibular cortex existed in patients with CUVP. Decreased FC and VMHC in the bilateral multisensory vestibular cortex may affect vestibular information integration, thus affecting self-motion perception, spatial orientation, and postural control.

Hyperventilation-Induced Nystagmus in Acute Unilateral Vestibulopathy: A Correlation with Vestibulo-ocular Reflex Gain and Clinical Implication.

Hyperventilation-induced nystagmus test (HINT) is capable of generating a response in 77.2% of cases of acute unilateral vestibulopathy (AUVP); both nystagmus toward the affected side (excitatory pattern) and toward the healthy side (inhibitory pattern) have been described. The aim of the study is to investigate the clinical and prognostic role of the test by evaluating its correlation with vestibulo-ocular reflex (VOR) gain. We evaluated 33 AUVP patients by performing the HINT and video head impulse test (V-HIT) during the acute phase and then at 15 and 90 days after the onset of the symptoms. The correlation between the VOR gain of the affected side and test responses was evaluated first, phase by phase, and then considering the pattern shown during the first assessments. Patients with a negative HINT had a higher mean VOR gain than patients with a positive test at both 15 and 90 days. Patients who showed an inhibitory pattern at the first assessment had a continuous improvement in V-HIT performance, while patients with an initial excitatory response had a transient decrease in gain at the subsequent evaluation (P=.001). No difference between these 2 groups emerged at 90 days (P=.09). The finding of a negative HINT during the follow-up correlates with good V-HIT performance and could be an indicator of good recovery. The inhibitory pattern is associated with a subsequent improvement; and it would be indicative of compensation. but, despite this, the prognostic value of the test is limited.

The clinical significance of arterial stiffness in the differential diagnosis of vertigo

Objectives: Pulse wave velocity (PWV) is a known indicator of arterial stiffness reflecting vascular damage. However, there are few reports of the relationship between PWV and dizziness/vertigo of a vascular origin. We investigated whether the PWV value could be useful as an ancillary measurement for identifying the etiology of dizziness/vertigo.Methods: We enrolled dizzy patients from March 2016 to December 2018. The patients with posterior circulation stroke presenting with dizziness/vertigo were categorized as having central vertigo. The patients with vertigo due to benign paroxysmal positional vertigo, Ménière disease, or acute unilateral vestibulopathy were categorized as having peripheral vertigo. The PWV value, ankle-brachial index (ABI), and traditional vascular risk factors were collected.Results: We consecutively enrolled a total of 93 participants. The PWV values were higher in the central vertigo group (p&lt;0.001), but ABI did not differ between the groups. Among the vascular risk factors, the number of patients with diabetes mellitus, dyslipidemia, and male patients was significantly higher in the central vertigo group. The brachial-ankle PWV (baPWV) values were higher in the central vertigo group, even after adjusting for confounding factors (p&lt;0.01). The receiver operating characteristic curve showed that the sensitivity was 74% and specificity was 81% when the mean baPWV value was 14.78 m/sec.Conclusions: Increased baPWV values were observed in patients with dizziness/vertigo due to stroke. Measurement of the baPWV value could be an ancillary test for evaluating the cause of dizziness/vertigo, even though more convincing evidence is still required.

The value of saccade metrics and VOR gain in detecting a vestibular stroke.

A normal video Head Impulse Test is the gold standard in the emergency department to rule-in patients with an acute vestibular syndrome and a stroke. We aimed to compare the diagnostic accuracy of vHIT metrics regarding the vestibulo-ocular reflex gain and the corrective saccades in detecting vestibular strokes. Prospective cross-sectional study (convenience sample) of patients presenting with acute vestibular syndrome in the emergency department of a tertiary referral centre between February 2015 and May 2020. We screened 1677 patients and enrolled 76 patients fulfilling the inclusion criteria of acute vestibular syndrome. All patients underwent video head impulse test with automated and manual data analysis. A delayed MRI served as a gold standard for vestibular stroke confirmation. Out of 76 patients, 52 were diagnosed with acute unilateral vestibulopathy and 24 with vestibular strokes. The overall accuracy of detecting stroke with an automated vestibulo-ocular reflex gain was 86.8%, compared to 77.6% for cumulative saccade amplitude and automatic saccade mean peak velocity measured by an expert and 71% for cumulative saccade amplitude and saccade mean peak velocity measured automatically. Gain misclassified 13.1% of the patients as false positive or false negative, manual cumulative saccade amplitude and saccade mean peak velocity 22.3%, and automated cumulative saccade amplitude and saccade mean peak velocity 28.9% respectively. We found a better accuracy of video head impulse test for the diagnosis of vestibular strokes when using the vestibulo-ocular reflex gain than using saccade metrics. Nevertheless, saccades provide an additional and important information for video head impulse test evaluation. The automated saccade detection algorithm is not yet perfect compared to expert analysis, but it may become a valuable tool for future non-expert video head impulse test evaluations.