Central positional nystagmus: an update

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.

Clinical spectrum of positional downbeat nystagmus: a diagnostic approach

Positional downbeat nystagmus (pDBN) is a common finding in dizzy patients, with etiologies ranging from benign paroxysmal positional vertigo (BPPV) to central vestibular lesions. Although peripheral pDBN often presents with distinct clinical features that differentiate it from BPPV, diagnosing its etiology can be challenging. A thorough clinical evaluation, including the physical characteristics of the nystagmus, response to positional maneuvers, and neurological findings, is often sufficient to diagnose conditions that provoke pDBN such as anterior canal BPPV, atypical posterior canal BPPV, and central causes. However, when the diagnosis remains uncertain, a brain MRI focusing on the posterior fossa is required. In human lesion models, the vestibulocerebellum (nodulus and uvula) is commonly implicated in pDBN. Central causes of positional vertigo include vascular events, tumors, immune mediated, toxicity, and demyelinating diseases. Ultimately, a significant number of cases will remain without a clear etiology despite extensive workup. Clinicians should be vigilant for signs suggesting central vestibular dysfunction at follow-up in cases of apparently refractory BPPV. The aim of this work is to provide a comprehensive overview of pDBN and offer a logical approach to its assessment, along with recommendations for future research directions.

Diagnostic Errors in the Acutely Dizzy Patient-Lessons Learned

Acute vertigo or dizziness is a frequent presentation to the emergency department (ED), making up between 2.1% and 4.4% of all consultations. Given the nature of the ED where the priority is triage, diagnostic delays and misdiagnoses are common, with as many as a third of vertebrobasilar strokes presenting with acute vertigo or dizziness being missed. Here, we review diagnostic errors identified in the evaluation and treatment of the acutely dizzy patient and discuss strategies to overcome them. Lessons learned include focusing on structured history taking, asking about timing and triggers to inform a targeted examination, assessing subtle ocular motor findings (e.g., by use of HINTS(+)), and avoiding overreliance on brain imaging (including early magnetic resonance imaging including diffusion-weighted sequences [DWI-MRI]). Importantly, up to 20% of DWI-MRI may be false negatives if obtained within the first 24-48 h after symptom onset. Likewise, overreliance on focal neurologic findings to confirm a stroke diagnosis should be avoided because isolated dizziness, vertigo, or even unsteadiness may be the only symptoms in some patients with vertebrobasilar stroke. Furthermore, in patients with triggered episodic vestibular symptoms provocation maneuvers should be preferred over HINTS(+), and a potential diagnosis of stroke should not be immediately dismissed in younger patients presenting with a headache (where migraine may be more common), but the possibility of a vertebral artery dissection should be further evaluated. Importantly, moderate training of non-experts allows for significant improvement in diagnostic accuracy in the acutely dizzy patient and thus should be prioritized.

Effect of benign paroxysmal positional vertigo course on residual symptoms after successful canalith repositioning procedures: A prospective controlled trial

BACKGROUND

Following successful canalith repositioning procedures (CRPs), some patients with benign paroxysmal positional vertigo (BPPV) may experience residual symptoms. There is currently no consensus on whether these residual symptoms are related to the disease duration.

OBJECTIVE

To examine the impact of BPPV duration on the persistence of residual symptoms following successful CRP.

METHODS

A total of 102 idiopathic BPPV patients were enrolled and categorized into short-course and long-course groups based on the duration of the disease. The course of disease in the short-course group was less than or equal to 7 days. The long course of disease was longer than 7 days. All patients underwent swivel-chair-assisted CRP and were followed up 7-10 days after successful CRP. The Dizziness Handicap Inventory (DHI) questionnaire was administered to all patients before and after CRP.

RESULTS

Before CRP, significant differences were observed between the two groups in total DHI score and its subdomains: Physical (DHI-P), Functional (DHI-F), and Emotional (DHI-E) (p < 0.05), indicating that long disease duration significantly affected all patient aspects. After CRP, significant differences remained in total DHI, DHI-P, DHI-F, and DHI-E scores (p < 0.05), with the long-course group consistently scoring higher. However, no significant differences were found in the changes in DHI scores across dimensions before and after CRP between the two groups.

CONCLUSION

The duration of BPPV did not influence CRP outcomes, but patients with a longer disease course were more likely to experience residual symptoms after successful CRP.

Repositioning chair treatment procedure for cupulolithiasis: case report (with video)

INTRODUCTION

A cupulolithiasis of the lateral semicircular canal is an accumulation of otolithic debris at the level of the cupula of the same canal. Its pathophysiology generally generates a specific clinical presentation. This situation can be very disabling for the patient and tricky to treat for the clinician.

CASE REPORT

The patient was a 70-year-old man with cupulolithiasis of the right lateral semicircular canal. We present here the conversion of cupulolithiasis to canalolithiasis using the Thomas Richard Vitton (TRV) repositioning chair, as well as the treatment of this canalolithiasis through a mechanical liberation maneuver.

CONCLUSION

The results of manual therapeutic maneuvers for Benign Paroxysmal Positional Vertigo (BPPV) are generally good regardless of the type of BPPV. It can sometimes be more challenging to resolve an ageotropic-type BPPV of the lateral semicircular canal and mechanically-assisted maneuvers using a repositioning chair may be required. Faced with symptom resistance despite attempts at multiple liberatory maneuvers, clinicians must be able to reconsider their initial diagnosis and investigate other potentially more serious origins of these symptoms. The TRV chair can be a treatment option in the management of cupulolithiasis, especially in cases where classic reduction maneuvers do not always yield good results.

Amplification of vibration induced nystagmus in patients with peripheral vestibular loss by head tilt

Introduction

In patients with unilateral loss of vestibular function (UVL) vibration of the skull leads to a response of the vestibulo-ocular reflex (VOR) called vibration-induced nystagmus (VIN), with slow phases usually directed toward the paretic ear. This response is thought to result from the difference between the neural discharge in semicircular canal afferents from the healthy and the affected labyrinth. The brain interprets this difference as a sustained imbalance in angular (rotational) vestibular tone, which in natural circumstances would only occur when the head was rotating at a constant acceleration.

Methods

To study this effect, we used a contemporary model of the neural network that combines sensory information about head rotation, translation, and tilt relative to gravity to estimate head orientation and motion. Based on the model we hypothesize that in patients with UVL, the brain may estimate not only a "virtual" rotation from the induced canal imbalance but also a subsequent "virtual" translation from the incorrect computation of the orientation of the head relative to gravity. If this is the case, the pattern of vibration-induced nystagmus will depend on the orientation of the head relative to gravity during the stimulation. This model predicts that this "virtual" translation will alter the baseline VIN elicited with the head upright; augmenting it when the affected ear is down and diminishing it when the affected ear is up.

Results

Confirming this hypothesis, we recorded VIN in 3 patients with UVL (due to vestibular neuritis) in upright, right ear-down, and left ear-down positions and each showed the expected pattern.

Discussion

From a practical, clinical view, our results and modeling suggest that positional VIN might reveal a hidden imbalance in angular vestibular tone in patients with UVL, when patients have equivocal signs of a vestibular imbalance, such as a minute amount of spontaneous or vibration-induced nystagmus with the head upright. This research provides insights into the underlying mechanisms of vestibular processing, the analysis of nystagmus in patients with UVL, and guides the design of a new bedside diagnostic test to assess vestibular function in patients with dizziness and imbalance.

Pendular Nystagmus Presenting in Usher Syndrome Type I: A Case Report

BACKGROUND

 We describe a 42-year-old patient with reported "shaking" vision referred due to concerns of possible vestibular system dysfunction. The patient has known history of Usher syndrome type I, bilateral cochlear implants, and severe vision impairment.

PURPOSE

 This case describes an unusual nystagmus previously only reported in individuals with central demyelinating disorders, significant light deprivation, or in congenital/early-onset visual pathway impairment.

RESEARCH DESIGN

 Case study.

DATA COLLECTION AND ANALYSIS

 Retrospective chart review of vestibular function.

RESULTS

 Vestibular function was likely absent in this case. There was no evidence of vestibular (jerk) nystagmus for sinusoidal harmonic acceleration stimuli or repeatable responses for cervical vestibular evoked myogenic potentials. Significant pendular low-amplitude high-frequency oscillations of approximately 6 Hz were present for horizontal and vertical tracings throughout testing.

CONCLUSION

 Nystagmus may not always be associated with vestibular system impairment. In this case, the patient's reported "shaking" vision was attributed to pendular low-amplitude high-frequency nystagmus and hypothesized to relate to long-standing significant vision impairment. This presentation is unusual in adults and has historically been associated with individuals with significant central pathology or in those with long duration light deprivation.

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.

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.

Posterior semicircular canal cupulolithiasis during acute pontomedullary demyelination

Positional vertigo poses a diagnostic challenge in people with multiple sclerosis (MS). The characteristics of positional nystagmus and its response to repositioning manoeuvres are usually sufficient to diagnose benign paroxysmal positional vertigo (BPPV). However, certain BPPV variants respond poorly to repositioning manoeuvres and their nystagmus pattern can resemble that of central positional vertigo caused by infratentorial demyelination. This diagnostic difficulty is particularly challenging if positional vertigo occurs during an MS relapse. We describe a woman with MS who developed a sixth nerve palsy and gaze-evoked nystagmus, caused by demyelination near or within areas classically involved in central positional vertigo. However, she also had positional vertigo from coincident BPPV (and not central positional vertigo). This was initially a treatment resistant-posterior semicircular canal cupulolithiasis but it later progressed to a posterior semicircular canal canalolithiasis, with symptoms promptly resolving after a repositioning manoeuvre.

Prevalence of benign paroxysmal positional vertigo in a population-based setting among 75-year-olds

BACKGROUND

Benign paroxysmal positional vertigo (BPPV) is one of the most frequently diagnosed cause of dizziness among older adults.

OBJECTIVE

To investigate the prevalence of BPPV and positional symptoms of dizziness and nystagmus among 75-year-olds and to identify factors associated with BPPV and positional dizziness and nystagmus.

METHODS

In this cross-sectional population-based study of 75-78-year-olds in Gothenburg, 887 participants were examined with questions regarding dizziness and health and social factors. A total of 681 participants underwent the Dix-Hallpike test or the side-lying test for BPPV using Video Frenzel goggles.

RESULTS

In total 32% reported problems with dizziness (n = 887). The prevalence of BPPV was 4% in the unweighted and 4.5% in the weighted analyses, compensating for selective attrition of women and participants with previous positional dizziness. Positional dizziness without nystagmus was found in 2% and nystagmus without dizziness was found in 9%. Individuals with BPPV and positional dizziness experienced more dizziness in everyday life compared with those with normal tests, while those with positional nystagmus did not.

CONCLUSIONS

The estimated prevalence of BPPV among 75-year-olds was 4.5%. Despite weighted analyses, the true prevalence may be higher since many participants with dizziness refused testing. Dizziness was associated with fear and discomfort so strong that around 20% of the participants declined testing.

Supporting a Tsonga learner living with Bardet-Biedl syndrome, a rare complex disability

Background

Bardet-Biedl syndrome (BBS) is a rare, systemic, hereditary disorder characterised by obesity, polydactyly, visual and auditory impairment, and cognitive disability. Providing quality education in appropriate schools for children who present with such complex chronic conditions is challenging.

Objectives

This study explored the dimensions of psycho-educational support needs for a child with BBS in South Africa to contribute to the improvement of early detection and holistic interventions.

Method

A descriptive in-depth qualitative case study of Gezani, an adolescent Tsonga boy diagnosed with BBS, was undertaken. Semi-structured interviews were conducted with his parents and teachers to ascertain the boy's psycho-educational support needs. Medical reports provided information on the complexities and prognosis of the syndrome. Observations in the classroom corroborated the learner's symptoms and behaviours.

Results

Thematic content analysis revealed the key areas of support needs. Gezani's cognitive disability required a modified, slow-paced curriculum. His visual impairment required mobility orientation training and learning Braille. His emotional needs were supported with psychotherapy to maintain a sense of well-being. Medical monitoring was recommended with interventions for walking and managing his diet and weight. Speech therapy supported his communication skills.

Conclusion

Learners with multiple disabilities require carefully planned, individualised psycho-educational support programmes addressing their unique needs and delays with targeted remedial interventions in appropriate special needs schools.

Contribution

This study informs educators about BBS and provides multi-faceted, holistic support. The Department of Basic Education could bring special schools and national policies in tighter alignment for learners presenting with complex disabilities.

Neurological update: neuro-otology 2023

Much has changed since our last review of recent advances in neuro-otology 7 years ago. Unfortunately there are still not many practising neuro-otologists, so that most patients with vestibular problems need, in the first instance, to be evaluated and treated by neurologists whose special expertise is not neuro-otology. The areas we consider here are mostly those that almost any neurologist should be able to start managing: acute spontaneous vertigo in the Emergency Room-is it vestibular neuritis or posterior circulation stroke; recurrent spontaneous vertigo in the office-is it vestibular migraine or Meniere's disease and the most common vestibular problem of all-benign positional vertigo. Finally we consider the future: long-term vestibular monitoring and the impact of machine learning on vestibular diagnosis.

When Particle Repositioning Maneuvers Just Will Not Stick: Clinical Considerations for Persistent Benign Paroxysmal Positional Vertigo

PURPOSE

Although benign paroxysmal positional vertigo (BPPV) is often considered benign and easily treatable, aberrant cases of persistent BPPV can be challenging to manage. Detailed differential diagnosis is essential as central-, vascular-, and cervical-related etiologies may mirror the presentation of persistent BPPV. In addition, an understanding of alternative noninvasive treatment options is important as persistent BPPV is often refractory to traditional particle repositioning maneuvers (PRMs). This article reviews clinical considerations for persistent BPPV.

METHOD

A case of a 68-year-old male diagnosed with posterior semicircular canal BPPV (PC-BPPV) and received various unsuccessful PRMs treatments is described. His clinical presentation is referenced alongside various possible etiologies to discern the most likely diagnosis. Nonsurgical treatment options for intractable PC-BPPV will also be reviewed.

CONCLUSIONS

BPPV recalcitrant to PRM treatment warrants investigation of other etiologies; however, key elements of the case history and objective examination are helpful for differential diagnosis. Brandt-Daroff exercises may facilitate habituation of symptoms secondary to persistent BPPV. More research is needed to understand the use of multiaxial repositioning chairs for the treatment of intractable BPPV.

Dispelling Mist That Obscures Positional Vertigo in Vestibular Migraine

(1) Background: Patients with vestibular migraine (VM) often present with positional vertigo. A portion of these patients have features of benign paroxysmal positional vertigo (BPPV). It is a challenge to rapidly identify the BPPV component of VM associated with positional vertigo. (2) Methods: Retrospective data collected from 60 VM and 47 VM + BPPV patients were used to build a diagnostic model, and then prospective data from 47 patients were used for the external validation. All patients had VM manifesting as positional vertigo, with or without accompanying BPPV. The clinical manifestations and the results of vestibular function tests were comprehensively analyzed using logistic regression. (3) Results: The univariate and multivariate analyses showed that the age, symptom duration, tinnitus, ear fullness, nausea, head shaking nystagmus, the direction of the Dix-Hallpike and roll tests, and horizontal gain could help differentiate between the two groups. A nomogram and an online calculator were generated. The C-index was 0.870. The diagnostic model showed good discriminative power and calibration performance during internal and external validation. (4) Conclusions: This study provided a new perspective for diagnosing VM with positional vertigo by identifying the BPPV component and, for the first time, offers a prediction model integrating multiple predictors.

Acute positional vertigo in the emergency department-peripheral vs. central positional nystagmus

Introduction

Benign paroxysmal positional vertigo (BPPV) is the most common cause of positional vertigo. However, positional vertigo can also be due to diseases affecting the central vestibular pathways, such as vestibular migraine. Accurate and timely diagnosis enables effective triage and management.

Objectives

To evaluate diagnoses made by emergency clinicians compared to acute vertigo specialists, in patients presenting to an emergency department (ED) with positional vertigo.

Methods

Following routine ED care, patients with a primary complaint of dizziness, vertigo, light-headedness or unsteadiness, underwent detailed neuro-otological assessment by acute vertigo specialists. Demographics and final diagnoses were recorded and analyzed.

Results

Of 71 consented patients (21-91 years; mean 56 years, ±16.7 years, 40 females), ED identified 13 with a peripheral cause of positional vertigo (mean 48.85 years, ±16.19, 8 females). Central positional nystagmus was not noted in any of the patients with positional vertigo seen by the ED clinicians. Acute vertigo specialists diagnosed nine patients with BPPV (age range 50-88 years, mean 66 years, ±12.22, 5 females), and six with central positional nystagmus (age range 23-59 years, mean 41.67 years, ±15.78, 6 females).

Conclusion

Positional vertigo should be assessed with positional maneuvers such as Dix-Hallpike and Roll tests in the ED to identify peripheral and central nystagmus features. Central causes are more common in younger females, with the presence of vomiting, and/or a background of motion sensitivity.

Comparison of clinical characteristics and vestibular function test results in patients with vestibular migraine and Menière's disease

OBJECTIVES

The differentiation between Vestibular Migraine (VM) and Meniere's Disease (MD) is difficult because of overlapping symptoms. The study aimed to compare the clinical characteristics and vestibular function test results between VM and MD patients.

METHODS

Seventy-one patients with definite VM and 31 patients with definite unilateral MD were included. All patients received Caloric Test (CT), Video Head Impulse Test (vHIT) and Vestibular Evoked Myogenic Potential (VEMP) test within 7 days after visiting the hospital. Results of these tests were compared between groups.

RESULTS

Most VM patients (64.0%) experienced spontaneous internal vertigo, while most MD patients (66.7%) experienced spontaneous external vertigo. MD patients had more severe vestibular symptoms and autonomic responses compared to VM patients during attacks (p =  0.03, p = 0.00, respectively). The nystagmus intensity of CT-induced was greater in VM patients than in MD patients (p = 0.003). More VM patients had CT intolerance and Central Positional Nystagmus (CPN) compared to MD patients (p = 0.002, p = 0.006, respectively). More MD patients had CT(+) and vHIT saccades wave compared to VM patients (p < 0.001, p = 0.002, respectively). The non-elicitation rate of cervical VEMP was higher, and the ocular VEMP amplitudes were lower in MD patients than in VM patients (p = 0.002, p = 0.018).

CONCLUSIONS

Vestibular symptoms during attacks combined with the results of vestibular function tests may be used to differentiate between VM and MD. The diverse nature of vestibular symptoms (especially internal vertigo), history of motion sickness and CT intolerance may provide clues to the diagnosis of VM, whereas spontaneous external vertigo, CT(+) with vHIT(-), and the presence of saccades may provide clues to the diagnosis of MD.

LEVEL OF EVIDENCE: 4

Early Diagnosis of Central Disorders Mimicking Horizontal Canal Cupulolithiasis

Background: Horizontal Canal Cupulolithiasis (hc-BPPV-cu) can mimic a pathology of central origin, so a careful examination is essential to prevent misdiagnosis. Methods: Retrospective cross-sectional cohort study of 45 patients suffering from suspected hc-BPPV-cu. We recorded whether patients first presented through an ENT Emergency Department (ED) or through an Outpatient Otolaryngology Clinic (OC). Results: We found statistically significant differences (p < 0.05) between the OC versus the ED in relation to the time between symptom onset and first assessment (79.7 vs. 3.6 days, respectively), the number of therapeutic maneuvers (one maneuver in 62.5% vs. 75.9%, and more than one in 25.1% vs. 13.7%), and multi-canal BPPV rate (43.8% vs. 3.4%). hc-BPPV-cu did not resolve in 2 patients (12.5%) from the OC and in 3 (10.3%) from de ED, all of which showed central pathology. Discussion: There are no prior studies that analyze the approach to hc-BPPV-cu in the ED. The benefits of early specialist input are early identification of central positional nystagmus, a decrease in symptom duration, reduced number of therapeutic maneuvers required for symptom resolution, and lower rates of iatrogenic multi-canal BPPV. Conclusion: A comprehensive approach to hc-BPPV-cu in the ED allows both more effective treatment and early identification of central disorder mimics.

Downbeat Nystagmus as a Presenting Manifestation of Neurolisteriosis in a Pregnant Woman

Listeria monocytogenes has tropism towards two immunologically "privileged" sites, the fetoplacental unit in pregnant women and the central nervous system (neurolisteriosis) in immunocompromised individuals. We report a case of neurolisteriosis in a previously asymptomatic pregnant woman from rural West Bengal, India, who presented with a subacute onset febrile illness with features of rhombencephalitis and a predominantly midline-cerebellopathy (slow and dysmetric saccades, florid downbeat nystagmus, horizontal nystagmus, and ataxia). With timely detection and the institution of prolonged intravenous antibiotic therapy, both the mother and the fetus were saved uneventfully.

Triple Benign Paroxysmal Positional Vertigo and the Strength of Remote Video-Based Management

This case report describes remote video-based diagnosis and management of triple posttraumatic benign paroxysmal positional vertigo.

Video head impulse testing in patients with isolated (hemi)nodular infarction

Background

Isolated (hemi)nodular strokes as underlying cause of acute dizziness are rare, thus there are still gaps of knowledge in the clinical presentation of affected patients. Clinical and experimental evidence has suggested that lesions involving the nodulus lead to various vestibulo-ocular deficits including prolonged velocity-storage, periodic-alternating nystagmus, positional nystagmus, abolished suppression of post-rotatory nystagmus by head-tilt and impaired verticality perception. At the bedside, the angular vestibulo-ocular reflex (aVOR), as assessed by the horizontal head-impulse test (HIT), has been reported to be normal, however quantitative assessments of all six semicircular canals are lacking.

Objective

The primary aim of this case series was to characterize the spectrum of clinical presentations in isolated (hemi)nodular strokes. Furthermore, based on preliminary observations, we hypothesized that the aVOR is within normal limits in isolated nodular strokes.

Methods

We retrospectively included patients with isolated (hemi)nodular stroke on diffusion-weighted MR-imaging from a prospective stroke-registry. All patients received a standardized bedside neuro-otological assessment and quantitative, video-based HIT (vHIT) of all six semicircular canals. Overall ratings of vHIT (normal vs. abnormal function) were performed independently by two reviewers and disagreements were resolved.

Results

Between January 2015 and December 2021 six patients with isolated nodular (n = 1) or heminodular (n = 5) ischemic stroke were included. Clinical presentation met diagnostic criteria for acute vestibular syndrome (AVS) in 5/6 patients and for episodic vestibular syndrome (EVS) in 1/6 patients. Ocular motor abnormalities observed included the presence of spontaneous horizontal nystagmus (n = 2), positional nystagmus (5/6), head-shaking nystagmus (3/6), skew deviation (n = 1), and moderate or severe truncal ataxia (5/6). Bedside HIT was normal in all patients and no gaze-evoked or periodic alternating nystagmus was observed. aVOR-gains were within normal range in all patients and overall aVOR-function as assessed by vHIT was rated as normal in all six patients.

Conclusions

Using quantitative, video-based testing of the horizontal and vertical aVOR, preserved integrity of the aVOR in (hemi)nodular strokes was confirmed, extending preliminary findings at the bedside. Furthermore, widespread deficits of both ocular stability, postural control and volitional eye movements were observed in our study cohort, being consistent with findings reported in previous studies.

Effectiveness and reliability of the four-step STANDING algorithm performed by interns and senior emergency physicians for predicting central causes of vertigo

BACKGROUND

For emergency physicians (EPs), acute vertigo is a challenging complaint and learning a reliable clinical approach is needed. STANDING is a four-step bedside algorithm that requires (1) identifying spontaneous nystagmus with Frenzel glasses or, alternatively, a positional nystagmus; (2) characterizing the nystagmus direction; (3) assessing the vestibuloocular reflex (head impulse test); and (4) assessing the gait. The objective was to determine its accuracy for diagnosing central vertigo when using by naïve examiners as such as interns and its agreement with senior EPs.

METHODS

This was a prospective 1-year diagnostic cohort study among patients with vertigo, vestibulovisual symptoms, or postural symptoms seen by 20 interns trained in the four-step examination. The algorithm was performed first by an intern and second by a senior EP and categorized as either worrisome when indicating a central diagnosis and benign or inconclusive when indicating a peripheral diagnosis. The reference test was diffusion-weighted brain magnetic resonance imaging.

RESULTS

Among 312 patients included, 57 had a central diagnosis including 33 ischemic strokes (10.5%). The main etiology was benign paroxysmal positional vertigo (32.7%). The likelihood ratios were 4.63 and 10.33 for a worrisome STANDING, 0.09 and 0.01 for a benign STANDING, and 0.21 and 0.35 for an inconclusive STANDING, for interns and senior EPs, respectively. The algorithm showed sensitivities of 84.8% (95% CI 75.6%-93.9%) and 89.8% (95% CI 82.1%-97.5%), negative predictive values of 96.2% (95% CI 93.7%-98.6%) and 97.5% (95% CI 95.5%-99.5%), specificities of 88.9% (95% CI 85.1%-92.8%) and 91.3% (95% CI 87.8%-94.8%), and positive predictive values of 64.1% (95% CI 53.5%-74.8%) and 70.7% (95% CI 60.4%-81.0%), respectively. The agreement between interns and senior EPs was very substantial (B-statistic coefficient: 0.77) and almost perfect for each step: (1) 0.87, (2) 0.98, (3) 0.95, and (4) 0.99.

CONCLUSIONS

With a single training session, the algorithm reached high accuracy and reliability for ruling out central causes of vertigo in the hands of both novices and experienced EPs. A future multicenter randomized controlled trial should further its impact on unnecessary neuroimaging use and patient's satisfaction.

Oculo-vestibular signs in experimentally induced migraine attacks: an exploratory analysis

Vestibular symptoms accompanying headache are quite common in migraine patients. Based on the association of vertigo with migraine, vestibular migraine was included in the appendix of the 3rd edition of the International Classification of Headache Disorders as a possible migraine subtype worthy of further investigation. In this post hoc, exploratory analysis, we investigated the occurrence of oculo-vestibular signs (OVSs) during experimentally induced migraine attacks in 24 episodic migraine patients and 19 healthy controls exposed to sublingual nitroglycerin (NTG - 0.9 mg). A comprehensive clinical examination was performed at baseline, at the onset of the migraine-like attack, and immediately before hospital discharge (180 minutes after NTG administration). Three of the 13 migraine patients who developed a spontaneous-like migraine attack during the hospital observation period (23.1%) also developed OVSs during the induction test. Noteworthy, none of the patients with a negative induction test developed OVSs and no OVSs were reported in healthy subjects at any time point. The exploratory nature of our study does not allow to draw definite conclusions on the possible implications of a vestibular dysfunction in migraine pathophysiology. Our results however suggest that NTG administration may lend itself to investigate vestibular dysfunction in migraine, at least in a subset of patients. The present findings represent a starting point for designing future ad hoc and well-powered studies.

Central positional vertigo as first initial multiple sclerosis symptom: A case report with systematic review

Multiple sclerosis is a disease that affects the central nervous system, resulting in various symptoms such as vision, physical activity, and stability. Central positional vertigo as initial multiple sclerosis symptoms are a rare case. It increases the attention of doctors to follow accurate measurements to diagnose multi sclerosis regarding the initial symptoms.

Erdheim-Chester Disease Revealed by Central Positional Nystagmus: A Case Report

Erdheim-Chester disease (ECD) is a rare histiocytic disorder, recently recognized to be neoplastic. The clinical phenotype of the disease is extremely heterogeneous, and depends on the affected organs, with the most frequently reported manifestations being bone pain, diabetes insipidus and neurological disorders including ataxia. In this article, we report on a case of a 48-year-old woman, whose initial symptom of gait instability was isolated. This was associated with positional nystagmus with central features: nystagmus occurring without latency, clinically present with only mild symptoms, and resistant to repositioning maneuvers. The cerebral MRI showed bilateral intra-orbital retro-ocular mass lesions surrounding the optic nerves and T2 hyperintensities in the pons and middle cerebellar peduncles. A subsequent CT scan of the chest abdomen and pelvis found a left “hairy kidney”, while ¹⁸ F-FDG PET-CT imaging disclosed symmetric 18F-FDG avidity predominant at the diametaphyseal half of both femurs. Percutaneous US-guided biopsy of perinephric infiltrates and the kidney showed infiltration by CD68(+), CD1a(-), Langerin(-), PS100(-) foamy histiocytes with BRAF^V600E mutation. The combination of the different radiological abnormalities and the result of the biopsy confirmed the diagnosis of ECD. Many clinical and radiological descriptions are available in the literature, but few authors describe vestibulo-ocular abnormalities in patients with ECD. Here, we report on a case of ECD and provide a precise description of the instability related to central positional nystagmus, which led to the diagnosis of ECD.

Atypical Positional Vertigo: Definition, Causes, and Mechanisms

Paroxysmal positional vertigo is a frequent cause for consultation. When approaching these patients, we try to differentiate central from peripheral causes, but sometimes we find manifestations that generate diagnostic doubts. In this review, we address atypical paroxysmal positional vertigo, reviewing the literature on the subject and giving a provisional definition of atypical positional vertigo as well as outlining its causes and pathophysiological mechanisms.