Classification of vestibular signs and examination techniques: Nystagmus and nystagmus-like movements

Usefulness of Nystagmus Patterns in Distinguishing Peripheral From Central Acute Vestibular Syndromes at the Bedside: A Critical Review

Vertigo and dizziness are amongst the most frequent presenting symptoms in the emergency room, accounting for up to 4% of all emergency consultations. The broadness of their differential diagnosis and the often transient nature of these symptoms pose a significant challenge to the treating physician. Combining various subtle oculomotor signs at the bedside has been very successful in distinguishing peripheral from central causes in acutely dizzy patients meeting diagnostic criteria for the acute vestibular syndrome (i.e., acute and prolonged vertigo or dizziness accompanied by nausea or vomiting, gait imbalance, motion intolerance, and [not mandatory] nystagmus). While the diagnostic accuracy of the HINTS (Head-Impulse-Nystagmus-Test-of-Skew) algorithm has been studied extensively, less is known about the value of various nystagmus patterns seen at the bedside in patients with an acute vestibular syndrome. Here we review both spontaneous and triggered presenting nystagmus patterns and discuss their impacts and limitations, including primary-gaze horizontal, vertical, and torsional nystagmus, nystagmus during eccentric gaze, and nystagmus triggered by stimuli such as head-shaking, hyperventilation, positional testing, vibration, and the Valsalva maneuver. We conclude that the usefulness of nystagmus patterns in discriminating peripheral and central causes strongly depends on the pattern seen and the type of testing performed, being highly predictive of a central cause for torsional and vertical spontaneous nystagmus, downbeat, or apogeotropic horizontal and treatment-refractory positional nystagmus. The predictive value for central causes was moderate only for vertical nystagmus after horizontal head-shaking ("perverted" head-shaking nystagmus) since it can also occur in peripheral cases, while the predictive value was low for vibration-induced nystagmus and Valsalva-induced nystagmus.

Nystagmus and Saccadic Intrusions

OBJECTIVE

This article describes the diagnosis and differentiation of the many possible localizations and causes of nystagmus.

LATEST DEVELOPMENTS

The eyes move to keep the fovea on the object of visual regard. To account for the movement of targets, the environment, or the self, different classes of eye movement are necessary to achieve visual stability. These movements involve the vergence, smooth pursuit, saccadic, vestibular, and optokinetic systems, as well as the ability to suppress the vestibuloocular reflex and other movements for steady fixation. When the equipoise of one or more of these systems is disrupted, nystagmus or saccadic intrusions may result. The astute clinician can distinguish between benign (eg, infantile or peripheral vestibular nystagmus) and dangerous (eg, stroke, Wernicke encephalopathy) etiologies with a high degree of confidence at the bedside, making expensive eye movement recording equipment unnecessary in the majority of cases.

ESSENTIAL POINTS

The recognition and interpretation of nystagmus and saccadic intrusions in the context of the history and a comprehensive ocular motor and neurologic examination is an essential skill in neurologic practice.

Evaluation of Acute Dizziness and Vertigo

Dizziness and vertigo are common presenting symptoms in acute care settings. This article describes the most common causes of acute dizziness and vertigo with practical, evidence-based guidance on evaluation of these patients. A timing-and-triggers approach should be used to first characterize the patient's vestibular symptoms as continuous or episodic. If acute and continuous, determine whether symptoms are post-exposure or spontaneous. If episodic, determine whether symptoms are triggered or spontaneous. Classify the patient as having post-exposure acute vestibular syndrome (AVS), spontaneous AVS, triggered episodic vestibular syndrome (EVS), or spontaneous EVS.

Inferior Vestibular Neuritis: Diagnostic Criteria, Clinical Features, and Prognosis-A Focused Review

Purpose: This review aims to analyze the diagnostic methods used to evaluate inferior vestibular nerve neuritis. Methods: We performed an electronic search on the PubMed database for clinical studies investigating the diagnostic techniques used for inferior vestibular nerve neuritis. Results: We initially identified 114 records in our search. After applying the inclusion and exclusion criteria, we narrowed it down to 12 studies. These studies collectively examined a total of 642 patients diagnosed with vestibular nerve neuritis, 64 of whom had inferior vestibular neuritis. Conclusions: The inferior vestibular neuritis is an unfrequent form of vestibular neuritis, often misdiagnosed. The diagnosis of inferior vestibular neuritis (IVN) is based on clinical history and vestibular testing, specifically reduced posterior canal gain on video head impulse test (vHIT), absent cervical VEMP (cVEMP), normal caloric responses, and preserved ocular VEMP (oVEMP). This review highlights the gaps in current diagnostic strategies and emphasizes the need for integrating advanced vestibular testing methods to enhance diagnostic accuracy for inferior vestibular nerve neuritis. Future studies should address the standardization of diagnostic protocols to facilitate broader clinical application.

Radiographic Horizontal Conjugate Gaze Deviation: Clinical Correlates

Purpose of Review

The potential diagnostic value of radiographic, horizontal, conjugate gaze deviation (Rad h-CGD) was first recognized in 2003 by Simon et al. Thereafter, interest grew related to its potential use as a marker of different neurologic and vestibular disorders. Over the past 20 years, we have identified clinical correlates of Rad h-CGD including those caused by supratentorial and infratentorial lesions. We propose clinicians and radiologists will better diagnose and manage patients by knowing the different diagnostic possibilities for Rad h-CGD.

Findings

We report different clinical correlates of Rad h-CGD relevant for localizing and lateralizing lesions. We measured the angle of deviation and correlated it with the clinical findings and underlying mechanisms. We then reviewed important data from the previous literature relevant to the localization of each lesion and combined it with our experience into the design of a practical algorithm to interpret Rad h-CGD.

Summary

Using Rad h-CGD provides useful information about the diagnosis and localization and may reveal subtle ocular findings not clear on physical examination. However, Rad h-CGD alone cannot distinguish between supratentorial and infratentorial lesions, and therefore, the clinical context is critical. Moreover, although Rad h-CGD occurs with strokes due to large vessel occlusion, it could also be seen with an acute vestibular syndrome, secondary to a peripheral vestibular neuritis. Other possibilities include ischemic events in the cerebellum, brainstem, and labyrinth.

New Fresnel lens loupe for nystagmus observation suitable for use by medical staff in emergency departments

BACKGROUND

Reduction of spontaneous nystagmus by fixation, a characteristic feature of peripheral nystagmus, is important for differentiating between peripheral and central vestibular disorders. In the emergency room, Frenzel goggles are recommended to observe spontaneous nystagmus for the differential diagnosis of acute vestibular syndrome. We developed a portable loupe with a Fresnel lens to observe nystagmus. The loupe does not require power supply and can be used under ceiling lights. The aim of this study was to quantitatively and objectively compare the abilities of the loupe and conventional Frenzel goggles to observe spontaneous nystagmus and to verify that the loupe can detect peripheral nystagmus that cannot be observed with the naked eye.

METHODS

Visual impact susceptibility was compared between the loupe and Frenzel goggles using the slow-phase velocity of nystagmus induced by the caloric test in 15 participants. Subsequently, under lighting, the nystagmus observations under the naked eye condition and with the use of the loupe were compared. Furthermore, the visibility of nystagmus was evaluated from recorded videographic images.

RESULTS

In observations of nystagmus induced by the caloric test, the visual impact of the loupe was not inferior to that of Frenzel goggles. The mean slow-phase velocity of nystagmus recorded with the loupe was significantly higher than that observed with the naked eye. Nystagmus weakened under bright lighting could be recovered by the loupe as fixation was blocked and the direction of the nystagmus could be defined.

CONCLUSIONS

The results showed that the loupe is helpful in observing nystagmus, which is weakly observed with the naked eye under bright light. This portable, low-cost loupe, which yields superior results, can serve as an alternative to conventional Frenzel goggles in emergency medical settings where rapid assessment is required.

Physical Activity and Frailty Are Impaired in Older Adults with Benign Paroxysmal Positional Vertigo

Background/Objectives: Benign Paroxysmal Positioning Vertigo (BPPV), diagnosed in 46% of older adults with complaints of dizziness, causes movement-related vertigo. This case-control study compared physical activity, frailty and subjective well-being between older adults with BPPV (oaBPPV) and controls. Methods: Thirty-seven oaBPPV (mean age 73.13 (4.8)) were compared to 22 matched controls (mean age 73.5 (4.5)). Physical activity was measured using the MOX accelerometer and the International Physical Activity Questionnaire. Modified Fried criteria assessed frailty. The Dizziness Handicap Inventory, Falls Efficacy Scale, and 15-item Geriatric Depression Scale assessed subjective well-being. A post-hoc sub-analysis compared all variables compared between frail oaBPPV, robust oaBPPV and robust controls. Significance level was set at α = 0.05. Results: oaBPPV were significantly less physically active and were more (pre-)frail (p < 0.001) compared to controls. They performed significantly less active bouts (p = 0.002) and more sedentary bouts (p = 0.002), and a significantly different pattern of physical activity during the day. OaBPPV reported significantly less time in transportation activities (p = 0.003), leisure (p < 0.001), walking (p < 0.001) and moderate-intensity activities (p = 0.004) compared to controls. Frail oaBPPV were even less active (p = 0.01) and experienced more fear of falling (p < 0.001) and feelings of depression (p < 0.001) than robust oaBPPV and controls. Conclusions: BPPV can induce a vicious cycle of fear of provoking symptoms, decreased physical activity, well-being and consequently frailty. It is also possible that frail and less physically active older adults have an increased prevalence of BPPV. Post-treatment follow-up should assess BPPV, frailty and physical activity to determine if further rehabilitation is needed.

Ocular Movement Examination in Peripheral Vestibular Disorders as a Tool to Improve Diagnosis: A Literature Review

Background and Objectives: This study reviews the current literature on ocular movements, specifically focusing on nystagmus associated with peripheral vestibular disorders, to enhance diagnostic accuracy. The evaluation of ocular movements, particularly nystagmus, provides essential insights into the function and dysfunction of the vestibular system, helping clinicians distinguish between peripheral and central causes of vertigo and imbalance. Materials and Methods: A comprehensive search of PubMed was conducted using key terms such as "ocular movements", "nystagmus", "vestibular nystagmus", and "peripheral vestibular disorders". Results: The search yielded 2739 titles, and after a rigorous selection process, 52 articles were reviewed in full. Discussion: The review highlights different classifications and types of nystagmus, including physiological and pathological forms, and their diagnostic relevance in vestibular disorders such as benign paroxysmal positional vertigo (BPPV), vestibular neuritis, and Meniere's disease. Diagnostic techniques like video/electro-oculography are emphasized for their role in assessing vestibular function and identifying abnormalities. The study underscores the importance of detailed ocular examination in the diagnosis of peripheral vestibular disorders and proposes an algorithm to aid this process. Conclusions: While not a systematic review, this study highlights the importance of detailed ocular examination in diagnosing peripheral vestibular disorders and presents an algorithm to facilitate this process. It also emphasizes the need for continued research and advancements in vestibular medicine to further understand ocular movements and their clinical significance, ultimately contributing to improved patient outcomes.

Clinical Aspects of Vertigo and Dizziness: What Should the Radiologist Know?

Dizziness and vertigo are common complaints in both emergency and outpatient settings, requiring careful evaluation to determine appropriate diagnosis and treatment. Differentiating between peripheral and central causes of dizziness is crucial for effective management. Peripheral causes, such as vestibular neuritis, benign paroxysmal positional vertigo, and Ménière's disease, are contrasted with central causes such as stroke, demyelinating diseases, and posterior fossa tumors. Diagnostic approaches include assessing nystagmus patterns, the vestibulo-ocular reflex, and the HINTS Plus test. Vestibular disorders are classified as acute, episodic, or chronic based on duration and symptom presentation. Imaging plays a significant role in identifying central causes when clinical findings are inconclusive. This paper provides a comprehensive overview of the clinical evaluation and diagnostic methods for dizziness and vertigo, with emphasis on distinguishing peripheral from central etiologies.

Central Positional Nystagmus Can Be the Sole Presentation of Cerebellar Nodulus Infarction

OBJECTIVES

To draw attention to acute positional vertigo and central positional nystagmus (CPN) developing as the sole features of cerebellar nodulus infarction.

BACKGROUND

The cerebellar nodulus is vascularized by the medial branch of the posterior inferior cerebellar artery, which also supplies the uvula, tonsil, tuber, and pyramid of the vermis, and the inferior part of the cerebellar hemisphere, making isolated cerebellar nodulus infarction extremely rare. CPN occurs after a change in head position with respect to gravity and is caused by pathologies involving the vestibulo-cerebellar pathways. CPN is rarely seen in isolation. Additional neurological signs and ocular motor abnormalities are generally present.

METHODS

A 62-year-old man was admitted to the emergency department with acute-onset positional vertigo and CPN as the sole finding on examination. Cranial magnetic resonance imaging revealed an acute infarction involving the nodulus. Results: Infarcts restricted to nodulus can cause positional vertigo and CPN without any associated neurological signs or ocul ar motor abnormalities.

CONCLUSION

Though very rare, cerebellar nodulus stroke must be searched in patients with positional vertigo of acute onset and isolated CPN on examination.

Assessments of Subjective Visual Gravity and Spontaneous Nystagmus in Patients With Vestibular Neuritis

OBJECTIVE

This study aimed to assess the correlation between the spontaneous nystagmus (SN) and the subjective visual vertical/horizontal (SVV/SVH) among patients with vestibular neuritis (VN) at the different head positions.

STUDY DESIGN

Case-control study.

SETTING

Affiliated Sixth People's Hospital, Shanghai Jiao Tong University School of Medicine.

METHODS

This study evaluated the SVV/SVH in both healthy subjects and patients with VN. These evaluations were performed in 5 different head positions: upright, 45° tilt to the left, 90° tilt to the left, 45° tilt to the right, and 90° tilt to the right. Additionally, the intensity of SN, as measured by slow-phase velocity, was recorded.

RESULTS

In patients with VN, a significant correlation was observed between SN and SVV/SVH in an upright position. The intensity of SN was higher when the head was tilted 90° toward the affected side compared to other positions. The SVV/SVH displayed an ipsiversive shift, when the head was tilted toward both the lesion and unaffected sides, exhibiting a contraversive direction. Furthermore, the changes in position-induced SN were consistent with the displacements of SVV and SVH caused by head tilt.

CONCLUSION

The presence of SN in patients with VN was observed to vary across different head position. These variations could potentially be attributed to the diverse activation patterns of the mechanical properties of otolith organs that are induced by head tilts.

Bilaterally positive head-impulse tests can differentiate AICA infarction from labyrinthitis

Introduction

Video head-impulse tests (video-HITs) often fail to detect anterior inferior cerebellar artery (AICA) infarction due to peripheral and central vestibular system involvement. Anecdotal studies suggest that video-HITs may reveal bilateral impairment in AICA infarction. However, the diagnostic utility of video-HITs has not been established, particularly when compared to labyrinthitis, which accounts for the majority of acute audiovestibular syndrome (AAVS) cases.

Methods

We reviewed the medical records of consecutive patients presenting with new-onset acute hearing loss and spontaneous vertigo (i.e., AAVS) between March 2018 and July 2023 at a tertiary hospital in South Korea. Video-HIT patterns were categorized as follows: (1) ipsilaterally positive, (2) contralaterally positive, (3) bilaterally normal, and (4) bilaterally positive.

Results

Twenty-eight patients with AICA infarction (mean age ± standard deviation = 67 ± 15 years; 14 men) and 51 with labyrinthitis (63 ± 17 years, 26 men) were included in the analyses. Among the 28 patients with AICA infarction, 15 presented with AAVS in isolation, without other co-morbid neurologic deficits (15/28, 54%). The vestibulo-ocular reflex (VOR) gains of ipsilesional horizontal canals (HCs) ranged from 0.21 to 1.22 (median = 0.81, interquartile range [IQR] = 0.50-0.89). However, those for contralateral HC gain ranged from 0.57 to 1.19 (median = 0.89 [IQR = 0.73-0.97]). Collectively, HITs were bilaterally positive in 13 patients (including 12 patients with bilaterally positive HITs for the horizontal canal), normal in eight, ipsilesionally positive in six, and contralesionally positive in one patient with AICA infarction. The VOR gains were typically decreased ipsilaterally in 28 (28/51, 55%), normal in 17 (17/51, 33%), and decreased bilaterally in six patients with labyrinthitis (6/51, 12%). Logistic regression analysis revealed that bilaterally positive HITs (p = 0.004) and multiple vascular risk factors (p = 0.043) were more frequently associated with AICA infarction than labyrinthitis.

Discussion

Among patients presenting with AAVS, bilaterally positive HITs can be indicative of AICA infarction in patients with multiple vascular risk factors.

Anterior Canal BPPV- A Rare Form of Vertical Canaloliathiasis: Series of 11 Cases

The most common cause of peripheral vertigo is Benign Paroxysmal Positional Vertigo (BPPV) primarily due to involvement of posterior semicircular canal. BPPV due to anterior canal is rare entity. This is a retrospective study, in which data of 628 patients who underwent vertigo test were analyzed. Amongst which 354 were patients of BPPV. It was found that 305 patients had posterior canal BPPV, 18 patients had lateral canal BPPV and 11 patients had anterior canal BPPV. The VNG data of 11 patients with anterior canal BPPV along with their treatment outcomes was analyzed. Of the eleven patients of anterior canal BPPV, ten patients had torsional nystagmus with or without downbeat nystagmus in Deep Head Hanging test. Only one patient had isolated downbeat nystagmus in Supine Head Hanging Test. Patients were treated with modified Yacovino's maneuver. Eight patients had immediate relief with modified Yacovino's repositioning maneuver. One patient had immediate conversion to left posterior canal BPPV and was treated for the same. Two patients presented with delayed conversion to posterior canal BPPV and were treated for the same. Anterior canal BPPV is rare but existent entity. It has a typical torsional and downbeat Nystagmus which is induced by Dix-Hallpike and Deep head hanging test. There is no reversal of nystagmus on getting up. It can be easily corrected by Yacovino's maneuver in the majority of the cases.

Visual Fixation of Skull-Vibration-Induced Nystagmus in Patients with Peripheral Vestibulopathy

Nystagmus induced by applying an intense vibratory stimulus to the skull (SVIN) indicates vestibular functional asymmetry. In unilateral vestibular loss, a 100 Hz bone-conducted vibration given to either mastoid immediately causes a primarily horizontal nystagmus. The test is performed in darkness to avoid visual fixation (VF) but there are no data about how much VF affects the often-intense SVIN. The aim is to analyze the amount of reduction in SVIN when VF is allowed during testing. Thus, all patients seen in a tertiary hospital for vertigo or dizziness with positive SVIN were included. SVIN was recorded for 10 s for each condition: without VF (aSVINwo) and with VF (aSVINw). We obtained an aSVINwo and an aSVINw as average slow-phase velocities (SPV) without and with VF. VF index (FISVIN) was calculated as the ratio of SPV. Among the 124 patients included, spontaneous nystagmus (SN) was found in 25% and the median slow phase velocity (mSPV) (without VF) of SN was 2.6 ± 2.4°/s. Mean FISVIN was 0.27 ± 0.29. FISVIN was 0 in 42 patients, and FISVIN between 0 and 1 was found in 82 (mean FISVIN 0.39 ± 0.02). Fixation suppression was found in all patients with SVIN in cases of peripheral vestibulopathy. FISVIN clearly delineates two populations of patients: with or without a complete visual reduction in nystagmus.

[Update on central oculomotor disorders and nystagmus]

The diagnosis of ocular motor disorders and the different forms of a nystagmus is based on a systematic clinical examination of all types of eye movements: eye position, spontaneous nystagmus, range of eye movements, smooth pursuit, saccades, gaze-holding function, vergence, optokinetic nystagmus, as well as testing of the function of the vestibulo-ocular reflex (VOR) and visual fixation suppression of the VOR. Relevant anatomical structures are the midbrain, pons, medulla, cerebellum, and cortex. There is a simple clinical rule: vertical and torsional eye movements are generated in the midbrain, horizontal in the pons. The cerebellum is relevant for almost all types of eye movements; typical pathological findings are saccadic smooth pursuit, gaze-evoked nystagmus or dysmetric saccades.Nystagmus is defined as a rhythmic, most often involuntary eye movement. It normally consists of a slow (pathological) drift of the eyes and a fast central compensatory movement of the eyes back to the primary position (re-fixation saccade). There are three major categories: first, spontaneous nystagmus, i. e. nystagmus which occurs in the gaze straight ahead position as upbeat or downbeat nystagmus; second, nystagmus that becomes visible at eccentric gaze only and third, nystagmus which can be elicited by certain maneuvers, e. g. head-shaking, head positioning, air pressure or hyperventilation, most of which are of peripheral vestibular origin. The most frequent central types of spontaneous nystagmus are downbeat and upbeat, infantile, pure torsional, pendular fixation, periodic alternating, and seesaw nystagmus. Many types of central nystagmus allow a precise neuroanatomical localization: for instance, downbeat nystagmus, which is most often caused by a bilateral floccular lesion or dysfunction, or upbeat nystagmus, which is caused by a lesion in the mesencephalon or medulla oblongata. Examples of pharmacotherapy are the use of 4-aminopyridine for downbeat and upbeat nystagmus, memantine or gabapentin for fixation pendular nystagmus or baclofen for periodic alternating nystagmus.

Deep Learning-Based Nystagmus Detection for BPPV Diagnosis

In this study, we propose a deep learning-based nystagmus detection algorithm using video oculography (VOG) data to diagnose benign paroxysmal positional vertigo (BPPV). Various deep learning architectures were utilized to develop and evaluate nystagmus detection models. Among the four deep learning architectures used in this study, the CNN1D model proposed as a nystagmus detection model demonstrated the best performance, exhibiting a sensitivity of 94.06 ± 0.78%, specificity of 86.39 ± 1.31%, precision of 91.34 ± 0.84%, accuracy of 91.02 ± 0.66%, and an F1-score of 92.68 ± 0.55%. These results indicate the high accuracy and generalizability of the proposed nystagmus diagnosis algorithm. In conclusion, this study validates the practicality of deep learning in diagnosing BPPV and offers avenues for numerous potential applications of deep learning in the medical diagnostic sector. The findings of this research underscore its importance in enhancing diagnostic accuracy and efficiency in healthcare.

Can head sway patterns differentiate between patients with Meniere's disease vs. peripheral vestibular hypofunction?

Background

Meniere's disease (MD) is defined by episodic vertigo, unilateral sensorineural hearing loss and fluctuating aural symptoms. Due to the variable clinical presentation, objective tests of MD may have significant diagnostic utility. Head kinematics derived from a head-mounted display (HMD) have demonstrated to be sensitive to vestibular dysfunction. The purpose of this pilot study was to investigate whether head sway can differentiate between patients with MD, vestibular hypofunction (VH) and healthy controls.

Materials/methods

80 adults (30 healthy controls, 32 with VH, and 18 with MD) were recruited from a tertiary vestibular clinic. All underwent a postural control assessment using the HTC Vive Pro Eye HMD that recorded head sway in the anterior-posterior (AP), medio-lateral (ML), pitch, yaw and roll direction. Participants were tested with 2 levels of visual load: a static versus oscillating star display. Each scene lasted 60 s and was repeated twice. Sway in each direction was quantified using root mean square velocity (VRMS) for the first 20 s and full 60 s of each scene.

Results

Static visual: participants with VH showed significantly larger head VRMS than controls in the AP (60 s and 20 s) and pitch (20 s) directions. Dynamic visual: participants with VH showed significantly larger head VRMS than controls all directions for both the 60 and 20 s analysis. Participants with MD did not differ significantly from the control or the VH group.

Conclusion

While limited in numbers, Patients with MD had a high variability in head sway in all directions, and their average head sway was between controls and those with VH. A larger sample as well as patients with worse symptoms at time of testing could elucidate whether head sway via HMD could become a viable test in this population. A similar finding between 20- and 60-s scene and the full portability of the system with an in-clinic testing setup could help these future endeavors. Head sway derived from HMD is sensitive to VH and can be clinically useful as an outcome measure to evaluate sensory integration for postural control.

Investigation on biomechanical responses in bilateral semicircular canals and nystagmus in vestibulo-ocular reflex experiments under different forward-leaning angles

Different head positions affect the responses of the vestibular semicircular canals (SCCs) to angular movement. Specific head positions can relieve vestibular disorders caused by excessive stimulating SCCs. In this study, we quantitatively explored responses of human SCCs using numerical simulations of fluid-structure interaction and vestibulo-ocular reflex (VOR) experiments under different forward-leaning angles of the head, including 0°, 10°, 20°, 30°, 40°, 50°, and 60°. It was found that the horizontal nystagmus slow-phase velocity and corresponding biomechanical responses of the cupula in horizontal SCC increased with the forward-leaning angles of the head, reached a maximum when the head was tilted 30° forward, and then gradually decreased. However, no obvious vertical or torsional nystagmus was observed in the VOR experiments. In the numerical model of bilateral SCCs, the biomechanical responses of the cupula in the left anterior SCC and the right anterior SCC showed the same trends; they decreased with the forward-leaning angles, reached a minimum at a 40° forward tilt of the head, and then gradually increased. Similarly, the biomechanical responses of the cupula in the left posterior SCC and in the right posterior SCC followed a same trend, decreasing with the forward-leaning angles, reaching a minimum at a 30° forward tilt of the head, and then gradually increasing. Additionally, the biomechanical responses of the cupula in both the anterior and posterior SCCs consistently remained lower than those observed in the horizontal SCCs across all measured head positions. The occurrence of these numerical results was attributed to the consistent maintenance of mutual symmetry in the bilateral SCCs with respect to the mid-sagittal plane containing the axis of rotation. This symmetry affected the distribution of endolymph pressure, resulting in biomechanical responses of the cupula in each pair of symmetrical SCCs exhibiting same tendencies under different forward-leaning angles of the head. These results provided a reliable numerical basis for future research to relieve vestibular diseases induced by spatial orientation of SCCs.

[The "difficult" patient-pearls and pitfalls of vestibular diagnostic tests: Part 2 : Difficult aspects of vestibular laboratory testing]

Patients with the cardinal symptoms "vertigo" or "dizziness" may be a real challenge for the treating otorhinolaryngologist. While the first part of this educational series was focused on history taking and bedside neurotological examination, the present paper is devoted to difficult aspects of vestibular laboratory testing, including getting the indication right, what to do if my patient is not able to fully cooperate during the tests, how to choose the adequate diagnostic procedure depending on the patient's comorbidities, how to interpret discordant results of various tests. Finally the paper addresses which conclusions can be drawn (and cannot be drawn) from normal findings in vestibular testing and how to communicate this result to the dizzy patient.

Three-dimensional characteristics of nystagmus induced by low frequency in semicircular canals of healthy young people

Objective

The study aimed to analyze the three-dimensional characteristics of nystagmus induced by different semicircular canal combinations in healthy young people, and to determine the reference range of nystagmus slow phase velocity (SPV) and its asymmetry.

Materials and methods

Fifty-two healthy volunteers (26 males and 26 females, aged 17-42 years, average 23.52 ± 6.59), were recruited to perform the manual triaxial rotation testing with a 3D-Videonystagmography (3D-VNG) device (VertiGoggles (ZT-VNG-II), Shanghai ZEHNIT Medical Technology Co., Ltd., Shanghai, China) using a 0.3 Hz prompt beat and a 90° amplitude, respectively. The induced nystagmus around the Z-, X-, and Y-axes were recorded in the yaw, pitch, and roll planes. The directions and slow phase velocities of the horizontal, vertical, and torsional components of the induced nystagmus under different semicircular canal combinations (the left lateral and right lateral semicircular canal combination, bilateral anterior semicircular canals, bilateral posterior semicircular canals combination, and the anterior and posterior semicircular canals combination of each ear), as well as their asymmetry, were taken as the observation indexes to analyze the characteristics of the nystagmus vectors of different combinations.

Results

Fifty-two healthy volunteers had no spontaneous nystagmus. The characteristic nystagmus was induced by the same head movement direction in all three axial rotation tests. The SPVs of the left and right nystagmus were 44.45 ± 15.75°/s and 43.79 ± 5.42°/s, respectively, when the subjects' heads were turned left or right around the Z-axis (yaw). The SPVs of vertically upward and downward nystagmus were 31.67 ± 9.46°/s and 30.01 ± 9.20°/s, respectively, when the subjects' heads were pitched around the X-axis (pitch). The SPVs of torsional nystagmus, with the upper poles of the eyes twisting slowly to the right and left ears (from the participant's perspective), were 28.99 ± 9.20°/s and 28.35 ± 8.17°/s, respectively, when the subjects' heads were turned left or right around the Y-axis (roll). There was no significant difference in the SPVs of nystagmus induced by the same rotation axis in two opposite directions (p > 0.05). The reference ranges for the slow phase velocities (SPVs) of nystagmus induced by the triaxial rotation testing were as follows: For the Z-axis (yaw), the SPVs were 13.58-75.32°/s for leftward head rotation and 13.56-74.02°/s for rightward head rotation. For the X-axis (pitch), the SPVs were 13.13-50.21°/s for upward head nystagmus and 11.98-48.04°/s for downward head nystagmus. For the Y-axis (roll), the SPVs were 10.97-47.02°/s for the left-sided head rotation and 12.34-44.35°/s for the right-sided head rotation.

Conclusion

This study clarified the three-dimensional characteristics of nystagmus induced by different semicircular canal combinations in healthy young people. It also established a preliminary reference range of SPVs and SPV asymmetry of nystagmus induced by the vertical semicircular canal. It can further provide a basis for the mechanism of semicircular canal-induced nystagmus and the traceability of nystagmus in patients with otogenic vertigo. It is shown that the portable 3D-VNG eye mask can be used for the manual triaxial rotation testing to achieve the evaluation of the low-frequency angular vestibulo-ocular reflex (aVOR) function of the vertical semicircular canal, which is convenient, efficient, and practical.

Association of self-efficacy, risk attitudes, and time preferences with functioning in older patients with vertigo, dizziness, and balance disorders in a tertiary care setting-Results from the MobilE-TRA2 cohort

Introduction

The functional burden of vertigo, dizziness, and balance problems (VDB) might depend on the personality traits of the patients affected. The aim of this study thus was to investigate the impact of self-efficacy, risk attitudes, and time preferences on functioning in older patients with VDB before and after treatment in a specialized tertiary care center.

Methods

Data for this study was obtained from the MobilE-TRA2 cohort study, conducted at a specialized tertiary care center in Germany. Patients aged 60 and older were assessed during their initial stay at the care center and 3 months later, using self-administered questionnaires. Self-efficacy was measured on a scale from 1 (very low) to 5 (very high). Health-related risk attitudes were inquired using an 11-point scale. Time preferences were measured by evaluating patients' willingness to postpone a reward in favor of a greater benefit on an 11-point Likert scale. Functioning was evaluated using the Dizziness Handicap Inventory, representing functional, emotional, and physical aspects of functional disability caused by VDB. Mixed-effects regression models were used to analyze the association between the selected personality traits and functioning over time. Interaction terms with time were incorporated for each personality trait, enabling the assessment of their influence on functioning 3 months following the initial observation period.

Results

An overall of 337 patients (53% women, median age at baseline = 70 years) were included. Patients with higher self-efficacy (Beta = -3.82, 95%-CI [-6.56; -1.08]) and higher willingness to take risks (Beta = -1.31, 95%-CI [-2.31; -0.31]) reported better functioning during their initial visit at the care center. Self-efficacy significantly predicted functioning after 3 months for overall functioning (Beta = -4.21, 95%-CI [-6.57; -1.84]) and all three domains.

Conclusion

Our findings suggest that patients with high self-efficacy and high willingness to take risks may exhibit better coping mechanisms when faced with the challenges of VDB. Promoting self-efficacy may help patients to better manage the duties accompanying their treatment, leading to improved functioning. These insights may inform the development of personalized treatment aimed at reducing the functional burden of VDB in older patients.

Capturing nystagmus during vertigo attacks using a smartphone: adherence, characteristics, pearls and pitfalls

OBJECTIVE

To investigate adherence, characteristics, and first clinical experiences of capturing ictal nystagmus at home, which can be performed to complement the diagnostic process in patients with episodic vestibular symptoms.

METHODS

Patients were recruited at a tertiary referral center in case capturing ictal nystagmus could contribute to the diagnostic process (e.g., to detect or rule out BPPV). They were asked to capture ictal nystagmus with their own smartphone at home, using a smartphone-based adapter (Nystagmocatcher, Balansdiagnos, Stockholm, Sweden). All recordings were analyzed by the last author (RvdB), and the adherence, characteristics, and first clinical experiences were evaluated.

RESULTS

Seventy patients with vestibular symptoms were asked to participate in this study. Sixty-two (89%) agreed to participate. The median period of participation was 86 days. Fifty-one patients experienced attacks during the study period. Eventually, 51% of them provided eye movement recordings sufficient for analysis. Different types of nystagmus were observed: positional nystagmus related to BPPV, positional nystagmus not related to BPPV, functional eye movements, and the absence of nystagmus or functional eye movements. Capturing ictal nystagmus could contribute to the diagnostic process in several ways, including to detect or rule out BPPV, to detect or rule out vestibular origin of symptoms, to determine the affected side, telemedicine, to monitor attack frequency, and to detect malingering. Furthermore, strict guidance of patients was necessary, which could be time-consuming.

CONCLUSION

Capturing ictal nystagmus can contribute to the diagnostic process in several ways, which motivates to rethink current clinical workflow in vestibular medicine. However, strict guidance is necessary and not all patients provide ictal recordings. In an outpatient setting, it would be advised to use ictal nystagmus recordings on indication, to complement the diagnostic process.

The "Vestibular Eye Sign"-"VES": a new radiological sign of vestibular neuronitis can help to determine the affected vestibule and support the diagnosis

INTRODUCTION

Nystagmus is a valuable clinical finding. Although nystagmus is often described by the direction of its quick phases, it is the slow phase that reflects the underlying disorder. The aim of our study was to describe a new radiological diagnostic sign called "Vestibular Eye Sign"-VES. This sign is defined as an eye deviation that correlates with the slow phase of nystagmus (vestibule pathological side), which is seen in acute vestibular neuronitis and can be assessed on a CT head scan.

MATERIALS AND METHODS

A total of 1250 patients were diagnosed with vertigo in the Emergency Department at Ziv Medical Center (ED) in Safed, Israel. The data of 315 patients who arrived at the ED between January 2010 and January 2022 were collected, with criteria eligible for the study. Patients were divided into 4 groups: Group A, "pure VN", Group B, "non-VN aetiology", Group C, BPPV patients, and Group D, patients who had a diagnosis of vertigo with unknown aetiology. All groups underwent head CT examination while in the ED.

RESULTS

In Group 1, pure vestibular neuritis was diagnosed in 70 (22.2%) patients. Regarding accuracy, VES (Vestibular Eye Sign) was found in 65 patients in group 1 and 8 patients in group 2 and had a sensitivity of 89%, specificity of 75% and a negative predictive value of 99.4% in group 1-pure vestibular neuronitis.

CONCLUSION

VN is still a clinical diagnosis, but if the patient undergoes head CT, we suggest using the "Vestibular Eye Sign" as a complementary sign. As per our findings, this is a valuable sign on CT imaging for diagnosing the pathological side of isolated pure VN. It is sensitive to support a diagnosis with a high negative predictive value.

Characteristics of spontaneous nystagmus and its correlation to video head impulse test findings in vestibular neuritis

Objective

To explore the direction and SPV (slow phase velocity) of the components of spontaneous nystagmus (SN) in patients with vestibular neuritis (VN) and the correlation between SN components and affected semicircular canals (SCCs). Additionally, we aimed to elucidate the role of directional features of peripheral SN in diagnosing acute vestibular syndrome.

Materials and methods

A retrospective analysis was conducted on 38 patients diagnosed with VN in our hospital between 2022 and 2023. The direction and SPV of SN components recorded with three-dimensional videonystagmography (3D-VNG) and the video head impulse test (vHIT) gain of each SCC were analyzed as observational indicators. We examined the correlation between superior and inferior vestibular nerve damage and the direction and SPV of SN components, and vHIT gain values in VN patients.

Results

The median illness duration of between symptom onset and moment of testing was 6 days among the 38 VN patients (17 right VN and 21 left VN). In total, 31 patients had superior vestibular neuritis (SVN), and 7 had total vestibular neuritis (TVN). Among the 38 VN patients, all had horizontal component with an SPV of (7.66 ± 5.37) °/s, 25 (65.8%) had vertical upward component with a SPV of (2.64 ± 1.63) °/s, and 26 (68.4%) had torsional component with a SPV of (4.40 ± 3.12) °/s. The vHIT results in the 38 VN patients showed that the angular vestibulo-ocular reflex (aVOR) gain of the anterior (A), lateral (L), and posterior (P) SCCs on the ipsilesional side were 0.60 ± 0.23, 0.44 ± 0.15 and 0.89 ± 0.19, respectively, while the gains on the opposite side were 0.95 ± 0.14, 0.91 ± 0.08, and 0.96 ± 0.11, respectively. There was a statistically significant difference in the aVOR gain between the A-, L-SCC on the ipsilesional side and the other SCCs (p < 0.001). The aVOR gains of A-, L-, and P-SCC on the ipsilesional sides in 31 SVN patients were 0.62 ± 0.24, 0.45 ± 0.16, and 0.96 ± 0.10, while the aVOR gains on the opposite side were 0.96 ± 0.13, 0.91 ± 0.06, and 0.98 ± 0.11, respectively. There was a statistically significant difference in the aVOR gain between the A-, L-SCC on the ipsilesional side and the other SCCs (p < 0.001). In 7 TVN patients, the aVOR gains of A-, L-, and P-SCC on the ipsilesional side were 0.50 ± 0.14, 0.38 ± 0.06, and 0.53 ± 0.07, while the aVOR gains on the opposite side were 0.93 ± 0.17, 0.90 ± 0.16, and 0.89 ± 0.09, respectively. There was a statistically significant difference in the aVOR gain between the A-, L-, and P-SCC on the ipsilesional side and the other SCCs (p < 0.001). The aVOR gain asymmetry of L-SCCs in 38 VN was 36.3%. The aVOR gain asymmetry between bilateral A-SCCs and bilateral P-SCCs for VN patients with and without a vertical upward component was 12.8% and 8.3%, which was statistically significant (p < 0.05). For VN patients with and without a torsional component, the aVOR gain asymmetry of bilateral vertical SCCs was 17.0% and 6.6%, which was statistically significant (p < 0.01). Further analysis revealed a significant positive correlation between the aVOR gain asymmetry of L-SCCs and the SPV of the horizontal component of SN in all VN patients (r = 0.484, p < 0.01), as well as between the asymmetry of bilateral vertical SCCs and the SPV of torsional component in 26 VN patients (r = 0.445, p < 0.05). However, there was no significant correlation between the aVOR gains asymmetry of bilateral A-SCCs and P-SCCs and the SPV of the vertical component in 25 VN patients.

Conclusion

There is a correlation between the three-dimensional direction and SPV characteristics of SN and the aVOR gain of vHIT in VN patients. These direction characteristics can help assess different SCCs impairments in patients with unilateral vestibular diseases.

Contextual sensory integration training vs. traditional vestibular rehabilitation: a pilot randomized controlled trial

BACKGROUND

We created a clinical virtual reality application for vestibular rehabilitation. Our app targets contextual sensory integration (C.S.I.) where patients are immersed in safe, increasingly challenging environments while practicing various tasks (e.g., turning, walking). The purpose of this pilot study was to establish the feasibility of a randomized controlled trial comparing C.S.I. training to traditional vestibular rehabilitation.

METHODS

Thirty patients with vestibular dysfunction completed the Dizziness Handicap Inventory (DHI), Activities-Specific Balance Confidence Scale (ABC), Visual Vertigo Analog Scale (VVAS), Functional Gait Assessment (FGA), Timed-Up-and-Go (TUG), and Four-Square Step Test (FSST). Following initial assessment, the patients were randomized into 8 weeks (once per week in clinic + home exercise program) of traditional vestibular rehabilitation or C.S.I. training. Six patients had to stop participation due to the covid-19 pandemic, 6 dropped out for other reasons (3 from each group). Ten patients in the traditional group and 8 in the C.S.I group completed the study. We applied an intention to treat analysis.

RESULTS

Following intervention, we observed a significant main effect of time with no main effect of group or group by time interaction for the DHI (mean difference - 18.703, 95% CI [-28.235, -9.172], p = 0.0002), ABC (8.556, [0.938, 16.174], p = 0.028), VVAS, (-13.603, [-25.634, -1.573], p = 0.027) and the FGA (6.405, [4.474, 8.335], p < 0.0001). No changes were observed for TUG and FSST.

CONCLUSION

Patients' symptoms and function improved following either vestibular rehabilitation method. C.S.I training appeared comparable but not superior to traditional rehabilitation.

TRIAL REGISTRATION

This study (NCT04268745) was registered on clincaltrials.gov and can be found at https://clinicaltrials.gov/ct2/show/NCT04268745 .

Multiple system atrophy with oculomotor abnormalities as a prominent manifestation: A case series

RATIONALE

Multiple system atrophy (MSA) is a group of adult-onset sporadic neurodegenerative diseases, mainly classified as MSA-C and MSA-P types. Due to the diversity of clinical symptoms, diagnosis faces a significant challenge. In the present case, we report a patient with isolated vertigo as the first presentation and abnormalities of the oculomotor system as the characteristic manifestations.

CASE CONCERN

A 64-year-old male had dizziness for 1 year, aggravated for 4 months, with accompanying symptoms of unsteady walking. Physical examination revealed spontaneous nystagmus, abnormal ataxic movements, and a broad basal gait. Video nystagmography revealed saccade intrusions and macrosaccadic oscillations, and opsoclonus. Magnetic resonance imaging (MRI) was unremarkable early, and positron emission tomography-computed tomography (PET-CT) announced a reduction in the volume of the cerebellum and brainstem.

DIAGNOSIS

The diagnosis of the possibility of MSA type-C, peripheral neuropathy, hypertension, and lacunar cerebral infarction was performed.

CONCLUSION

Atypical early clinical presentation may lead to delays, and identifying the critical problem through the patient simple clinical status requires long-term clinical experience and various ancillary examination tools.

Systematic review and meta-analysis of the diagnostic accuracy of spontaneous nystagmus patterns in acute vestibular syndrome

Objectives

For the assessment of patients presenting with acute prolonged vertigo meeting diagnostic criteria for acute vestibular syndrome (AVS), bedside oculomotor examinations are essential to distinguish peripheral from central causes. Here we assessed patterns of spontaneous nystagmus (SN) observed in AVS and its diagnostic accuracy at the bedside.

Methods

MEDLINE and Embase were searched for studies (1980-2022) reporting on the bedside diagnostic accuracy of SN-patterns in AVS patients. Two independent reviewers determined inclusion. We identified 4,186 unique citations, examined 219 full manuscripts, and analyzed 39 studies. Studies were rated on risk of bias (QUADAS-2). Diagnostic data were extracted and SN beating-direction patterns were correlated with lesion locations and lateralization.

Results

Included studies reported on 1,599 patients, with ischemic strokes (n = 747) and acute unilateral vestibulopathy (n = 743) being most frequent. While a horizontal or horizontal-torsional SN was significantly more often found in peripheral AVS (pAVS) than in central AVS (cAVS) patients (672/709 [94.8%] vs. 294/677 [43.4%], p < 0.001), torsional and/or vertical SN-patterns were more prevalent in cAVS than in pAVS (15.1 vs. 2.6%, p < 0.001). For an (isolated) vertical/vertical-torsional SN or an isolated torsional SN specificity (97.7% [95% CI = 95.1-100.0%]) for a central origin etiology was high, whereas sensitivity (19.1% [10.5-27.7%]) was low. Absence of any horizontal SN was more frequently observed in cAVS than in pAVS (55.2 vs. 7.0%, p < 0.001). Ipsilesional and contralesional beating directions of horizontal SN in cAVS were found at similar frequency (28.0 vs. 21.7%, p = 0.052), whereas for pAVS a contralesional SN was significantly more frequent (95.2 vs. 2.5%, p < 0.001). For PICA strokes presenting with horizontal SN, beating direction was ipsilesional more often than contralesional (23.9 vs. 6.4%, p = 0.006), while the opposite was observed for AICA strokes (2.2 vs. 63.0%, p < 0.001).

Conclusions

(Isolated) vertical and/or torsional SN is found in a minority (15.1%) of cAVS patients only. When present, it is highly predictive for a central cause. A combined torsional-downbeating SN-pattern may be observed in pAVS also in cases with isolated lesions of the inferior branch of the vestibular nerve. Furthermore, in cAVS patients the SN beating direction itself does not allow a prediction on the lesion side.

Torsional nystagmus recognition based on deep learning for vertigo diagnosis

Introduction

Detection of torsional nystagmus can help identify the canal of origin in benign paroxysmal positional vertigo (BPPV). Most currently available pupil trackers do not detect torsional nystagmus. In view of this, a new deep learning network model was designed for the determination of torsional nystagmus.

Methods

The data set comes from the Eye, Ear, Nose and Throat (Eye&ENT) Hospital of Fudan University. In the process of data acquisition, the infrared videos were obtained from eye movement recorder. The dataset contains 24521 nystagmus videos. All torsion nystagmus videos were annotated by the ophthalmologist of the hospital. 80% of the data set was used to train the model, and 20% was used to test.

Results

Experiments indicate that the designed method can effectively identify torsional nystagmus. Compared with other methods, it has high recognition accuracy. It can realize the automatic recognition of torsional nystagmus and provides support for the posterior and anterior canal BPPV diagnosis.

Discussion

Our present work complements existing methods of 2D nystagmus analysis and could improve the diagnostic capabilities of VNG in multiple vestibular disorders. To automatically pick BPV requires detection of nystagmus in all 3 planes and identification of a paroxysm. This is the next research work to be carried out.

Diagnosing the benign paroxysmal positional vertigo via 1D and deep-learning composite model

BACKGROUND

Benign Paroxysmal Positional Vertigo (BPPV) is the leading cause of vertigo, and its characteristic nystagmus induced by positional maneuvers makes it a good model for Artificial Intelligence (AI) diagnosis. However, during the testing procedure, up to 10 min of indivisible long-range temporal correlation data are produced, making the AI-informed real-time diagnosing unlikely in clinical practice.

METHODS

A combined 1D and Deep-Learning (DL) composite model was proposed. Two separate cohorts were recruited, with one for model generation and the other for evaluation of model's real-world generalizability. Eight features, including two head traces and three eye traces and their corresponding slow phase velocity (SPV) value, were served as the inputs. Three candidate models were tested, and a sensitivity study was conducted to determine the saliently important features.

RESULTS

The study included 2671 patients in the training cohort and 703 in the test cohort. A hybrid DL model achieved a micro-area under the receiver operating curve (AUROC) of 0.982 (95% CI 0.965, 0.994) and macro-AUROC of 0.965 (95% CI 0.898, 0.999) for overall classification. The highest accuracy was observed for right posterior BPPV, with an AUROC of 0.991 (95% CI 0.972, 1.000), followed by left posterior BPPV, with an AUROC of 0.979 (95% CI 0.940, 0.998), the lowest AUROC was 0.928 (95% CI 0.878, 0.966) for lateral BPPV. The SPV was consistently identified as the most predictive feature in the models. If the model process is carried out 100 times for a 10-min data, one single running takes 0.79 ± 0.06 s.

CONCLUSION

This study designed DL models which can accurately detect and categorize the subtype of BPPV, enabling a quick and straightforward diagnosis of BPPV in clinical setting. The critical feature identified in the model helps expand our understanding of this disorder.

Capturing nystagmus in the emergency room: posterior circulation stroke versus acute vestibular neuritis

OBJECTIVES

To compare acute nystagmus characteristics of posterior circulation stroke (PCS) and acute vestibular neuritis (AVN) in the emergency room (ER) within 24 h of presentation.

METHODS

ER-based video-nystagmography (VNG) was conducted, recording ictal nystagmus in 101 patients with PCS (on imaging) and 104 patients with AVN, diagnosed on accepted clinical and vestibular test criteria.

RESULTS

Patients with stroke in the brainstem (38/101, affecting midbrain (n = 7), pons (n = 19), and medulla (n = 12)), cerebellum (31/101), both (15/101) or other locations (17/101) were recruited. Common PCS territories included posterior-inferior-cerebellar-artery (41/101), pontine perforators (18/101), multiple-territories (17/101) and anterior-inferior-cerebellar-artery (7/101). In PCS, 44/101 patients had no spontaneous nystagmus. Remaining PCS patients had primary position horizontal (44/101), vertical (8/101) and torsional (5/101) nystagmus. Horizontal nystagmus was 50% ipsiversive and 50% contraversive in lateralised PCS. Most PCS patients with horizontal nystagmus (28/44) had unidirectional "peripheral-appearing" nystagmus. 32/101 of PCS patients had gaze-evoked nystagmus. AVN affected the superior, inferior or both divisions of the vestibular nerve in 55/104, 4/104 and 45/104. Most (102/104) had primary position horizontal nystagmus; none had gaze-evoked nystagmus. Two inferior VN patients had contraversive torsional-downbeat nystagmus. Horizontal nystagmus with SPV ≥ 5.8 °/s separated AVN from PCS with sensitivity and specificity of 91.2% and 83.0%. Absent nystagmus, gaze-evoked nystagmus, and vertical-torsional nystagmus were highly specific for PCS (100%, 100% and 98.1%).

CONCLUSION

Nystagmus is often absent in PCS and always present in AVN. Unidirectional 'peripheral-appearing' horizontal nystagmus can be seen in PCS. ER-based VNG nystagmus assessment could provide useful diagnostic information when separating PCS from AVN.

Positional End-Point Nystagmus during Positional Testing: Prevalence, Characteristics and Differences with Benign Paroxysmal Positional Vertigo

BACKGROUND

Some individuals present positional end-point nystagmus when the Dix-Hallpike tests are performed on them if they unintentionally look towards the examined ear.

OBJECTIVE

To describe the prevalence and the characteristics of end-point nystagmus during positional testing in healthy subjects.

METHODS

Sixty healthy subjects were included. Eight positional tests were performed on them, two Pagnini-McClure tests and six Dix-Hallpike tests, while keeping the eyes in different positions; one on each side. Two independent observers filled in a questionnaire about the presence of positional nystagmus, its latency, duration, direction, and sense.

RESULTS AND CONCLUSIONS

Of the subjects, 65% showed positional end-point nystagmus. This nystagmus had a short latency and last for as long as the head is maintained in the test position. They can show any direction or sense, but the most common are torsional clockwise in left tests and anticlockwise in right tests. Unlike BPPV, this nystagmus did not appear with the eyes in the straight-ahead position, it is asymptomatic, and its intensity does not decline.

Spontaneous nystagmus with an upbeat component: Central or peripheral vestibular disorders?

Objective

To determine the topical diagnosis and etiologies of spontaneous nystagmus (SN) with an upbeat component.

Methods

We retrospectively recruited 43 patients with SN with an upbeat component at a university hospital in China from 2020 to 2022. SN with an upbeat component was divided into pure upbeat nystagmus (UBN), SN with a predominant upbeat component, and SN with a non-predominant upbeat component. We analyzed their clinical and neurotologic findings and the final diagnosis.

Results

Fourteen (32.6%) of them showed pure UBN, while 29 (67.4%) exhibited SN mixed with an upbeat component, mixed upbeat-horizontal in 15, mixed upbeat-horizontal-torsional in 13, and upbeat-torsional in the remaining one. Pure UBN and SN with a predominant upbeat component were more common in central than in peripheral vestibular disorders [16 (80.0%) vs. 0 (0%), Chi-Square test, p < 0.001]. Central vestibular disorders were diagnosed in 20 (46.5%) patients, peripheral in 14 (32.6%), and undetermined in nine (20.9%) patients. The underlying causes mainly included acute unilateral peripheral vestibulopathy (n = 11), posterior circulation infarction (n = 9), benign recurrent vertigo (n = 4), vestibular migraine (VM, n = 3), and VM of childhood (n = 2).

Conclusion

SN with an upbeat component can be seen in both central and peripheral vestibular disorders. Pure UBN was a characteristic sign of central vestibular dysfunction. Central vestibular disorders should be highly suspected when patients show pure UBN or SN with a predominant upbeat component.

The 3D characteristics of nystagmus in posterior semicircular canal benign paroxysmal positional vertigo

Objective

The aim of this study was to observe the 3-dimensional (3D; horizontal, vertical, and torsional) characteristics of nystagmus in patients with posterior semicircular canal canalithiasis (PSC-can)-related benign paroxysmal positional vertigo (BPPV) and investigate its correlation with Ewald's.

Methods

In all, 84 patients with PSC-can were enrolled. The latency, duration, direction, and slow-phase velocity induced by the Dix-Hallpike test in the head-hanging and sitting positions were recorded using 3D video nystagmography (3D-VNG). The characteristics of the horizontal, vertical, and torsional components of nystagmus were quantitatively analyzed.

Results

3D-VNG showed that the fast phase of the vertical components and torsional components of left and right ear PSC-can as induced by the head-hanging position of the Dix-Hallpike test were upward, clockwise and counterclockwise, and horizontal components were mainly contralateral. The median slow-phase velocity of each of the three components for consecutive 5 s was 26.3°/s (12.3-45.8), 25.0°/s (15.7-38.9), and 9.2°/s (4.9-13.7). When patients were returned to the sitting position, the fast phase of the vertical and torsional components of nystagmus was reversed. Only 54 patients had horizontal components of nystagmus, and 32 of them remained in the same direction. The median slow-phase velocity of the three components for consecutive 5 s was 9.4°/s (6.0-11.7), 6.8°/s (4.5-11.8), and 4.9°/s (2.8-8.0). The ratios of the slow-phase velocity of the horizontal, vertical, and torsional components of the head-hanging position to the sitting position were close to 1.85 (1.0-6.6), 3.7 (1.9-6.6), and 5.1 (2.6-11.3). The ratios of the slow-phase velocity of the vertical to horizontal component, the torsional to horizontal component, and the vertical to torsional component of the head-hanging position were close to 3.3 (1.7-7.6), 3.9 (1.8-7.6), and 1.0 (0.5-1.8). The ratios of the slow-phase velocity of the vertical to horizontal component, the torsional to horizontal component, and the vertical to torsional component of the sitting position were close to 2.1 (1.1-6.8), 1.5 (1.0-3.8), and 1.2 (0.8-2.8).

Conclusion

There were three components of nystagmus induced by the Dix-Hallpike test in patients with PSC-can. The vertical component was the strongest and the horizontal component was the weakest. The 3D characteristics of nystagmus were consistent with those of physiological nystagmus associated with the same PSC with a single-factor stimulus, in accordance with Ewald's law.

Outcome for dizzy patients in a physiotherapy practice: an observational study

BACKGROUND

Dizziness is a common reason for referral to physiotherapy. Additional information on clinical characteristics, treatment effect and prognostic indicators in physiotherapy practice are needed.

METHODS

A retrospective observational study. Based on a standardised clinical evaluation patients were labelled as having Benign Paroxysmal Positioning Vertigo (BPPV) or not (no-BPPV). BPPV was treated with repositioning manoeuvres and exercises. In no-BPPV, treatment was based on additional clinical tests. Treatment was provided once per week and considered successful when the patient was free of symptoms confirmed by negative positional tests.

RESULTS

From 148 referred patients, 88 were labelled as having BPPV, 60 as no-BPPV. The symptom of a short-lasting spinning sensation provoked by head movements was highly suggestive of BPPV. On average, in BPPV treatment was completed after 2.27 ± 1.68 treatments, in no-BPPV this was after 4.91 ± 3.46 treatments. The delayed outcome was related to higher 'age' and 'concomitant neck pain' in BPPV and with higher 'age' only in no-BPPV. Favourable outcome was related to the feature 'dizziness provoked by movements in the horizontal plane' in BPPV.

CONCLUSIONS

Clinical evaluation and treatment in physiotherapy practice can be an effective and safe option for patients with dizziness. Several clinical variables with prognostic values were identified.Key messagesClinical evaluation and treatment in physiotherapy practice can be part of low threshold care for dizzy patients.Despite prior medical screening, one-third of patients without signs of BPPV were sent back for further evaluation, illustrating the need for interdisciplinary collaboration.Based on the description of the dizziness symptom (vertigo rather than light-headedness), provocation of the dizziness by movements, and a short duration of the dizziness attack, and positive clinical vestibular tests, BPPV treatment could be initiated.

Direction-changing spontaneous nystagmus in patients with dizziness

PURPOSE

The present study aimed to investigate the clinical features of patients with direction-changing spontaneous nystagmus (DCSN) and gain insight into its underlying mechanisms.

METHODS

Medical records and vestibular function test results collected in our dizziness clinic between February 2013 and February 2020 were retrospectively reviewed. Spontaneous nystagmus was recorded while sitting upright using videonystagmography for 2 min to confirm the spontaneous changes in nystagmus direction. Causative disease diagnoses were based on the patients' clinical history, audiometry results, vestibular function tests, and imaging studies.

RESULTS

Of 4786 patients, DCSN was observed in 41 (0.86%). Causative disease diagnoses included vestibular neuritis (n = 9), lateral semicircular canal cupulopathy (n = 9), cerebellopontine angle tumor (n = 8), vestibular paroxysmia (n = 2), vestibular migraine (n = 2), vestibular nucleus infarction (n = 1), sudden sensorineural hearing loss with vertigo (n = 2), Meniere's disease (n = 2), Ramsay Hunt syndrome (n = 1), labyrinthine fistula due to middle ear cholesteatoma (n = 1), lateral semicircular canal dysplasia (n = 1), post tympanomastoidectomy dizziness (n = 1), and head trauma (n = 2).

CONCLUSIONS

Although the periodicity of DCSN could not be determined because of insufficiently long observation times, it was observed in various central and peripheral vestibulopathies. Careful examination of spontaneous nystagmus over a sufficient period may ensure the detection of DCSN when evaluating dizziness.

Acute unilateral vestibulopathy/vestibular neuritis: Diagnostic criteria

This paper describes the diagnostic criteria for Acute Unilateral Vestibulopathy (AUVP), a synonym for vestibular neuritis, as defined by the Committee for the Classification of Vestibular Disorders of the Bárány Society. AUVP manifests as an acute vestibular syndrome due to an acute unilateral loss of peripheral vestibular function without evidence for acute central or acute audiological symptoms or signs. This implies that the diagnosis of AUVP is based on the patient history, bedside examination, and, if necessary, laboratory evaluation. The leading symptom is an acute or rarely subacute onset of spinning or non-spinning vertigo with unsteadiness, nausea/vomiting and/or oscillopsia. A leading clinical sign is a spontaneous peripheral vestibular nystagmus, which is direction-fixed and enhanced by removal of visual fixation with a trajectory appropriate to the semicircular canal afferents involved (generally horizontal-torsional). The diagnostic criteria were classified by the committee for four categories: 1. "Acute Unilateral Vestibulopathy", 2. "Acute Unilateral Vestibulopathy in Evolution", 3. "Probable Acute Unilateral Vestibulopathy" and 4. "History of Acute Unilateral Vestibulopathy". The specific diagnostic criteria for these are as follows:"Acute Unilateral Vestibulopathy": A) Acute or subacute onset of sustained spinning or non-spinning vertigo (i.e., an acute vestibular syndrome) of moderate to severe intensity with symptoms lasting for at least 24 hours. B) Spontaneous peripheral vestibular nystagmus with a trajectory appropriate to the semicircular canal afferents involved, generally horizontal-torsional, direction-fixed, and enhanced by removal of visual fixation. C) Unambiguous evidence of reduced VOR function on the side opposite the direction of the fast phase of the spontaneous nystagmus. D) No evidence for acute central neurological, otological or audiological symptoms. E) No acute central neurological signs, namely no central ocular motor or central vestibular signs, in particular no pronounced skew deviation, no gaze-evoked nystagmus, and no acute audiologic or otological signs. F) Not better accounted for by another disease or disorder."Acute Unilateral Vestibulopathy in Evolution": A) Acute or subacute onset of sustained spinning or non-spinning vertigo with continuous symptoms for more than 3 hours, but not yet lasting for at least 24 h hours, when patient is seen; B) - F) as above. This category is useful for diagnostic reasons to differentiate from acute central vestibular syndromes, to initiate specific treatments, and for research to include patients in clinical studies."Probable Acute Unilateral Vestibulopathy": Identical to AUVP except that the unilateral VOR deficit is not clearly observed or documented."History of acute unilateral vestibulopathy": A) History of acute or subacute onset of vertigo lasting at least 24 hours and slowly decreasing in intensity. B) No history of simultaneous acute audiological or central neurological symptoms. C) Unambiguous evidence of unilaterally reduced VOR function. D) No history of simultaneous acute central neurological signs, namely no central ocular motor or central vestibular signs and no acute audiological or otological signs. E) Not better accounted for by another disease or disorder. This category allows a diagnosis in patients presenting with a unilateral peripheral vestibular deficit and a history of an acute vestibular syndrome who are examined well after the acute phase.It is important to note that there is no definite test for AUVP. Therefore, its diagnosis requires the exclusion of central lesions as well as a variety of other peripheral vestibular disorders. Finally, this consensus paper will discuss other aspects of AUVP such as etiology, pathophysiology and laboratory examinations if they are directly relevant to the classification criteria.

New onset episodic vertigo as a presentation of vestibular neuritis

Objective

Vestibular neuritis (VN) is a common peripheral cause of acute vestibular syndrome, characterized by sustained vertigo and gait instability, persisting from 1 day to several weeks. With the widespread use of comprehensive vestibular function tests, patients with VN and non-sustained vertigo have drawn attention. In this study, we retrospectively analyzed the clinical presentation of patients with VN and episodic vertigo, aiming to expand the atypical clinical features of VN.

Methods

This retrospective study enrolled 58 patients with VN. Among them, 11 patients with more than 3 remissions per day, each lasting over 1 h were assigned to the episodic vertigo (EV) group, and 47 subjects without significant relief into the sustained vertigo (SV) group. Demographic information, clinical manifestations and data of supplementary examinations were collected and statistically analyzed. These patients were followed up 1 year after discharge to gather prognostic information.

Results

The incidence of spontaneous nystagmus (SN) and proportion of severe vertigo (Dizziness Handicap Inventory questionnaire score >60) in the SV group were significantly higher than those in the EV group. Spearman correlation showed that with a longer disease course, the velocity of overt saccade was smaller (p < 0.05, Rs = −0.263) in all patients with VN.

Conclusion

The non-sustained manifestations in VN overlap with a wider spectrum of other vestibular disorders and stroke-related vertigo, which add an additional layer of complexity to the differential diagnosis of new onset episodic vertigo. By retrospectively analyzing the clinical characteristics and vHIT parameters, our study has expounded on the atypical features and potential pathophysiological mechanism of episodic syndromes in VN. VOR gain and saccades measured by vHIT could be reliable indicators for vestibular rehabilitation process.

Prevention of Recurrent Benign Paroxysmal Positional Vertigo: The Role of Combined Supplementation with Vitamin D and Antioxidants

Benign paroxysmal positional vertigo (BPPV) usually has a favorable course, although it is possible to observe BPPV with a high recurrence rate. Previous studies suggested that vitamin D deficiency might affect BPPV recurrences, and oxidative stress might play a complementary role in BPPV pathogenesis. This multicentric trial aimed to evaluate the effectiveness of oral nutritional supplementation with a compound of alpha-lipoic acid, Carnosine, and Zinc (LICA® (Difass International, Coriano (RN), Italy)), vitamins of group B and vitamin D in preventing BPPV recurrences. A total of 128 patients with high recurrence-BPPV were randomized in three arms: Arm 1 consisted of subjects with “insufficient” or “deficient” vitamin D blood levels, treated with daily oral supplementation of LICA®, vitamins of group B and vitamin D3 (800 UI), Arm 2 included BPPV subjects with “sufficient” vitamin D who did not receive any nutritional support, and Arm 3 included subjects with a “sufficient” serum concentration of vitamin D who received supplementation with a compound of LICA® and Curcumin. After six months of follow-up, a significant reduction of BPPV relapses compared to the baseline was found only in Arm 1 (−2.32, 95% CI: 3.41−1.62, p-value < 0.0001). Study results suggested that oral nutritional supplementation with vitamin D3 plus antioxidants can prevent relapses in patients suffering from high recurrence-BPPV.

Vestibular Disease

The vestibular system (VS) is the primary specialized sensory system responsible for maintaining balance (equilibrium) and orientation of the eyes, neck, trunk, and limbs during rest and movement. Two important reflexes are responsible for maintaining balance: vestibulo-ocular and vestibulospinal reflexes. These reflexes involve peripheral and central components of the VS. Whether central or peripheral disease, most of the disorders of the VS result in ipsilateral neurologic deficits. A few uncommon exceptions present with contralateral signs to the site of the lesion. This article provides a brief review of functional anatomy, vestibular disease, clinical signs, and examples of disorders affecting the VS.

Is it possible to diagnose Posterior Semicircular Canal BPPV from the sitting position? The role of the Head Pitch Test and the upright tests along the RALP and LARP planes

PURPOSE

The diagnosis of benign paroxysmal positional vertigo (BPPV) involving the posterior semicircular canal (PSC) is traditionally entrusted to positioning tests where patients are rapidly brought in the supine position. This prospective study aims to define the role of a diagnostic protocol for PSC-BPPV including only upright tests.

MATERIALS AND METHODS

109 patients with PSC-BPPV were enrolled. The Head Pitch Test (HPT) was carried out first. If uneventful, the patient's head was turned 45° to each side and bent back-and-forth along the plane aligning either with the right anterior-left posterior (RALP) or left anterior-right posterior (LARP) canals, thus performing the upright RALP / upright LARP (uRALP/uLARP) test. Nystagmus observed was used to predict the diagnosis, which was therefore confirmed by Dix-Hallpike tests.

RESULTS

PSC-BPPV could be correctly diagnosed in 75.2% of cases with the sole HPT and in 87.2% of cases by adding the uRALP/uLARP test (Upright Protocol). The time elapsed from symptoms onset was closely related to the protocol sensitivity, as it reached 100% (64/64) in acute patients while decreased to 68.9% (31/45) in cases evaluated after 7 days (p < 0.001).

CONCLUSIONS

Upright maneuvers could correctly diagnose PSC-BPPV in most cases. uRALP/uLARP test demonstrated to improve the sensitivity of the HPT, mainly in recent-onset BPPV.

Acute Unilateral Peripheral Vestibulopathy After COVID-19 Vaccination: Initial Experience in a Tertiary Neurotology Center

Objective

The aim of the present study was to identify patients who developed acute unilateral peripheral vestibulopathy (AUPVP) after COVID-19 vaccination.

Methods

For this single-center, retrospective study, we screened the medical records of our tertiary interdisciplinary neurotology center for patients who had presented with AUPVP within 30 days after COVID-19 vaccination (study period: 1 June−31 December 2021). The initial diagnosis of AUPVP was based on a comprehensive bedside neurotological examination. Laboratory vestibular testing (video head impulse test, cervical and ocular vestibular evoked myogenic potentials, dynamic visual acuity, subjective visual vertical, video-oculography, caloric testing) was performed 1–5 months later.

Results

Twenty-six patients were diagnosed with AUPVP within the study period. Of those, n = 8 (31%) had developed acute vestibular symptoms within 30 days after COVID-19 vaccination (mean interval: 11.9 days, SD: 4.8, range: 6–20) and were thus included in the study. The mean age of the patients (two females, six males) was 46 years (SD: 11.7). Seven patients had received the Moderna mRNA vaccine and one the Pfizer/BioNTech mRNA vaccine. All patients displayed a horizontal(-torsional) spontaneous nystagmus toward the unaffected ear and a pathological clinical head impulse test toward the affected ear on initial clinical examination. Receptor-specific laboratory vestibular testing performed 1–5 months later revealed recovery of vestibular function in two patients, and heterogeneous lesion patterns of vestibular endorgans in the remaining six patients.

Discussion and Conclusions

The present study should raise clinicians' awareness for AUPVP after COVID-19 vaccination. The relatively high fraction of such cases among our AUPVP patients may be due to a certain selection bias at a tertiary neurotology center. Patients presenting with acute vestibular symptoms should be questioned about their vaccination status and the date of the last vaccination dose. Furthermore, cases of AUPVP occurring shortly after a COVID-19 vaccination should be reported to the health authorities to help determining a possible causal relationship.

Apogeotropic Horizontal Canal Benign Paroxysmal Positional Vertigo: Zuma e Maia Maneuver versus Appiani Variant of Gufoni

Benign paroxysmal positional vertigo (BPPV) is one of the most common disorders that causes dizziness. The incidence of horizontal semicircular canal (HSC) BPPV ranges from 5% to 40.5% of the total number of BPPV cases diagnosed. Several studies have focused on establishing methods to treat BPPV caused by the apogeotropic variant of the HSC, namely, the Appiani maneuver (App). In 2016, a new maneuver was proposed: the Zuma e Maia maneuver (ZeM), based on inertia and gravity. The aim of this study is to analyze the efficacy of App versus ZeM in the resolution of episodes of BPPV produced by an affectation of the horizontal semicircular canal with apogeotropic nystagmus (Apo-HSC). A retrospective, quasi-experimental study was conducted. Patients attended in office (November 2014–February 2019) at a third-level hospital and underwent a vestibular otoneurology assessment. Those who were diagnosed with Apo-HSC, treated with App or ZeM, were included. To consider the efficacy of the maneuvers, the presence of symptoms and/or nystagmus at the first follow up was studied. Patients classified as “A” were those with no symptoms, no nystagmus; “A/N+”: no symptoms, nystagmus present during supine roll test; “S”: symptoms present. Previous history of BPPV and/or otic pathology and calcium levels were also compiled. From the 54 patients included, 74% were women. The average age was 69. Mean follow-up: 52.51 days. In those patients without previous history of BPPV (n = 35), the probability of being group “A” was 63% and 56% (p = 0.687) when treated with App and ZeM, respectively, while being “A/N+” was 79% and 87% for App and ZeM (p = 0.508). Of the 19 patients who had previous history of BPPV, 13% and 64% were group “A” when treated with App and ZeM (p = 0.043), and 25% and 82% were “A/N+” after App and ZeM, respectively (p = 0.021). In conclusion, for HSC cupulolithiasis, ZeM is more effective than App in those cases in which there is a history of previous episodes of BPPV (“A”: 64% (p = 0.043); “A/N+”: 82% (p = 0.021)).

A Deep Learning Model for Three-Dimensional Nystagmus Detection and Its Preliminary Application

Symptoms of vertigo are frequently reported and are usually accompanied by eye-movements called nystagmus. In this article, we designed a three-dimensional nystagmus recognition model and a benign paroxysmal positional vertigo automatic diagnosis system based on deep neural network architectures (Chinese Clinical Trials Registry ChiCTR-IOR-17010506). An object detection model was constructed to track the movement of the pupil centre. Convolutional neural network-based models were trained to detect nystagmus patterns in three dimensions. Our nystagmus detection models obtained high areas under the curve; 0.982 in horizontal tests, 0.893 in vertical tests, and 0.957 in torsional tests. Moreover, our automatic benign paroxysmal positional vertigo diagnosis system achieved a sensitivity of 0.8848, specificity of 0.8841, accuracy of 0.8845, and an F1 score of 0.8914. Compared with previous studies, our system provides a clinical reference, facilitates nystagmus detection and diagnosis, and it can be applied in real-world medical practices.

The clinical significance of direction-fixed mono-positional apogeotropic horizontal nystagmus

Objective

A mono-positional persistent, direction-fixed apogeotropic nystagmus (MPosApoNy) is very challenging for the neuro-otologist. MPosApoNy can be found in patients suffering from a partially compensated acute unilateral vestibulopathy; with a normal caloric test, one can speculate the presence of “trapped” otolithic debris located close to the ampulla of the horizontal semicircular canal.

Methods

Among 957 patients suffering from vertigo and dizziness, we selected 53 cases of MPosApoNy.

Results

In 28 patients, caloric test showed a canal paresis on the same side of the MPosApoNy. In the remaining 25 cases, MPosApoNy was the only clinical finding. We hypothesised the presence of horizonal canal lithiasis and patients were treated with a Gufoni manoeuvre, followed by a forced prolonged position.

Conclusions

Performing bedside examination in a patient suffering from vertigo, the presence of MPosApoNy may be due to: a) facilitation of a subclinical nystagmus due to the mechanism of apogeotropic reinforcement; b) horizontal canal lithiasis with ‘trapped’ otoliths close to the ampulla. The disappearance of MPosApoNy following a repositioning manoeuvre or conversion in a typical form of canalolithiasis may represent the best method to confirm this hypothesis.

Otoneurological assessment and quality of life of individuals with complaints of dizziness and temporomandibular disorders: a case-control study

OBJECTIVES

To evaluate the impact of temporomandibular disorders on the quality of life of patients with dizziness.

METHODS

An observational, case-control study evaluated 60 individuals with dizziness (20 cases and 40 controls), who were matched for gender and age. The individuals underwent to anamnesis, overall physical and otoneurological examination, tonal and vocal audiometry and impedanciometry, video head impulse test and the dizziness handicap inventory questionnaire.

RESULTS

The otoscopy was normal for all patients. There was an association between the presence of temporomandibular disorders and aural fullness (p < 0.01) and otalgia (p < 0.01). Audiometry was normal in 90% of the patients in the case group, with a significant association between temporomandibular disorders and normal audiometry (p < 0.01). The video head impulse test findings were normal in 66% of the patients in the case group and 45% of the control group, and there was no association between having temporomandibular disorders and vestibular alterations at the video head impulse test (p = 0.12). There were significant differences in total dizziness handicap inventory and in the functional and emotional domains (p < 0.01), with higher scores in the control group.

CONCLUSION

Aural fullness and otalgia symptoms are associated with temporomandibular disorders in patients with dizziness, and there is an association between normal complementary audiological tests and temporomandibular disorders. Vestibular alterations are not associated with temporomandibular disorders. However, patients with dizziness and without temporomandibular disorders showed greater quality of life impairment.

LEVEL OF EVIDENCE: 3

Original case-control study.

Bechterew's Phenomenon in Bilateral Sequential Vestibular Neuritis: A Report of Two Cases

The brain can compensate for the vestibular imbalance. When the unilateral labyrinthine function is lost, the asymmetry between the peripheral vestibular inputs is compensated centrally by readjusting the signal difference from both ears and regaining vestibular balance. If the other healthy labyrinth is destroyed, the vestibular nuclei become imbalanced again, creating spontaneous nystagmus even though there is no input to the vestibular nuclei from either labyrinth. This is called Bechterew's phenomenon; a rare and not widely recognized phenomenon that occurs in cases of bilateral sequential vestibular neuritis. This is of clinical importance because spontaneous nystagmus with bilaterally absent or diminished caloric responses may give a misleading impression of a central lesion rather than a second peripheral lesion superimposed upon the effects of central compensation for the first. Although well-documented in experimental animals, this phenomenon rarely occurs in human beings. The objective of this study is to highlight the characteristics and the progression of test results from two patients from our own experience. Along with careful history taking and physical examination, a complex interpretation of various vestibular function tests, including induced nystagmus, head impulse test, caloric test, and fundus photography, is needed to make an accurate diagnosis of bilateral sequential vestibular neuritis (BSVN).

Vascular vertigo and dizziness: Diagnostic criteria

This paper presents diagnostic criteria for vascular vertigo and dizziness as formulated by the Committee for the Classification of Vestibular Disorders of the Bárány Society. The classification includes vertigo/dizziness due to stroke or transient ischemic attack as well as isolated labyrinthine infarction/hemorrhage, and vertebral artery compression syndrome. Vertigo and dizziness are among the most common symptoms of posterior circulation strokes. Vascular vertigo/dizziness may be acute and prolonged (≥24 hours) or transient (minutes to  < 24 hours). Vascular vertigo/dizziness should be considered in patients who present with acute vestibular symptoms and additional central neurological symptoms and signs, including central HINTS signs (normal head-impulse test, direction-changing gaze-evoked nystagmus, or pronounced skew deviation), particularly in the presence of vascular risk factors. Isolated labyrinthine infarction does not have a confirmatory test, but should be considered in individuals at increased risk of stroke and can be presumed in cases of acute unilateral vestibular loss if accompanied or followed within 30 days by an ischemic stroke in the anterior inferior cerebellar artery territory. For diagnosis of vertebral artery compression syndrome, typical symptoms and signs in combination with imaging or sonographic documentation of vascular compromise are required.

Identification of Stroke and TIA in Patients With Acute Dizziness, Vertigo or Imbalance in Emergency Departments of Primary Care Hospitals: Early Experiences With a Network-Based Telemedical Approach

Background

Acute dizziness, vertigo, and imbalance are frequent and difficult to interpret symptoms in the emergency department (ED). Primary care hospitals often lack the expertise to identify stroke or TIA as underlying causes. A telemedical approach based on telestroke networks may offer adequate diagnostics and treatment.

Aim

The aim of this study is to evaluate the accuracy of a novel ED algorithm in differentiating between peripheral and central vestibular causes.

Methods

Within the Telemedical Project for Integrative Stroke Care (TEMPiS), a telemedical application including a videooculography (VOG) system was introduced in 2018 in 19 primary care spoke hospitals. An ED triage algorithm was established for all patients with acute dizziness, vertigo, or imbalance of unknown cause (ADVIUC) as a leading complaint. In three predefined months, all ADVIUC cases were prospectively registered and discharge letters analyzed. Accuracy of the ED triage algorithm in differentiation between central and peripheral vestibular cases was analyzed by comparison of ED diagnoses to final discharge diagnoses. The rate of missed strokes was calculated in relation to all cases with a suitable brain imaging. Acceptance of teleconsultants and physicians in spoke hospitals was assessed by surveys.

Results

A total number of 388 ADVIUC cases were collected, with a median of 12 cases per months and hospital (IQR 8–14.5). The most frequent hospital discharge diagnoses are vestibular neuritis (22%), stroke/TIA (18%), benign paroxysmal positioning vertigo (18%), and dizziness due to internal medicine causes (15%). Detection of a central vestibular cause by the ED triage algorithm has a high sensitivity (98.6%), albeit poor specificity (45.9%). One stroke out of 32 verified by brain scan was missed (3.1%). User satisfaction, helpfulness of the project, improvement of care, personal competence, and satisfaction about handling of the VOG systems were rated consistently positive.

Discussion

The concept shows good acceptance for a telemedical and network-based approach to manage ADVIUC cases in the ED of primary care hospitals. Identification of stroke cases is accurate, while specificity needs further improvement. The concept could be a major step toward a broadly available state of the art diagnostics and therapy for patients with ADVIUC in primary care hospitals.