Can Bedside Oculomotor (HINTS) Testing Differentiate Central From Peripheral Causes of Vertigo?

Role of incubitus truncal ataxia, and equivalent standing grade 3 ataxia in the diagnosis of central acute vestibular syndrome

INTRODUCTION AND OBJECTIVES

acute vestibular syndrome is a diagnostic challenge, requiring a rapid and precise diagnosis to take therapeutic actions. Truncal ataxia, inability to sit still, and Babinski flexor dysergy were evaluated. Material anf methods: 52 patients with central pathology (stroke in aica and pica territory) and vestibular neuritis were prospectively studied. MRI of the brain was used as the gold standard.

RESULTS

A combination of grade 2-3 ataxia to differentiate patients with vestibular neuritis from patients with stroke resulted in a 92% sensitivity (95% CI 79-100%), a 67% specificity (95% CI 47-86%). Flexion asynergy had a 70% sensitivity (95% CI 47-92%), and an 88% specificity (95% CI 69-100%). The inability to sit still correlated well with truncal ataxia.

CONCLUSIONS

vestibulospinal signs are useful in the differential diagnosis of acute vestibular syndromes, and the inability to sit is a good substitute for truncal ataxia when it cannot be evaluated.

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.

Applicability of Oculomotor Tests for Predicting Central Vestibular Disorder Using Principal Component Analysis

The videonystagmography oculomotor test battery is considered useful method for diagnosing vertigo. However, its role in diagnosing central vestibular disorder has not been clarified due to variations in interpretation. Patients (n = 103) with vertigo or dizziness symptoms undergoing the oculomotor tests and brain MRI within 1 month were analyzed. Two otology specialists retrospectively interpreted the oculomotor tests, and three neurology and neuroradiology specialists determined whether central lesions were present on brain MRI. Multivariable logistic regression analysis was performed to determine the factors contributing to discordant interpretation between oculomotor tests and brain MRI. Oculomotor tests predicting central lesions were assessed using principal component analysis. The intra- and inter-rater reliability in oculomotor test interpretation was moderate to good. Age > 60 years and multiple comorbidities were significant predictors of a discordant interpretation between MRI and oculomotor tests. Positive neurological symptoms and a higher oculomotor index (according to saccade (vertical axis), smooth pursuit (horizontal axis), and gaze-evoked nystagmus (horizontal/vertical axes) tests) significantly predicted central vestibular disorder in vertigo patients. Caution is required when interpreting the results of the oculomotor test battery for diagnosis of central lesions in older patients, as well as in those with multiple comorbidities.

Diagnostic and prognostic utility of computed tomography perfusion imaging in posterior circulation acute ischemic stroke: A systematic review and meta-analysis

BACKGROUND

Computed tomography perfusion (CTP) imaging could be useful in the diagnosis of posterior circulation stroke (PCS) and in identifying patients who are likely to experience favorable outcomes following reperfusion therapy. The current study sought to investigate the diagnostic and prognostic capability of CTP in acute ischemic PCS by performing a systematic review and meta-analysis.

METHODS

Medline/PubMed and the Cochrane Library were searched using the terms: "posterior circulation", "CT perfusion", "acute stroke", and "reperfusion therapy". The following studies were included: (1) patients aged 18 years or above; (2) patients diagnosed with PCS; and (3) studies with good methodological design. Pooled sensitivity (SENS), specificity (SPEC), and area under the curve (AUC), computed using the summary receiver operating characteristic (SROC) curves, were used to determine diagnostic/prognostic capability.

RESULTS

Out of 14 studies included, a meta-analysis investigating diagnostic accuracy of CTP was performed on nine studies. Meta-analysis demonstrated comparable diagnostic accuracy of CTP to non-contrast computed tomography (NCCT) (AUC_CTP : 0.90 [95% CI 0.87-0.92] vs. AUC_NCCT : 0.96 [95% CI 0.94-0.97]); however, with higher pooled sensitivity (SENS_CTP : 72% [95% CI 57%-83%] vs. SENS_NCCT : 25% [95% CI 17%-35%]) and lower specificity (SPEC_CTP : 90% [95% CI 83%-94%] vs. SPEC_NCCT : 96% [95% CI 95%-98%]) than NCCT. Meta-analysis to determine prognostic capability of CTP could not be performed.

CONCLUSIONS

CTP has limited diagnostic utility in acute ischemic PCS, albeit with superior diagnostic sensitivity and inferior diagnostic specificity to NCCT. Further prospective trials are required to validate the prognostic capability of CTP-derived parameters in PCS.

Value of copeptin and the S-100b protein assay in ruling out the diagnosis of stroke-induced dizziness pattern in emergency departments

Background

Dizziness is a frequent reason for visiting emergency departments (EDs). Differentiating stroke from other causes is challenging for physicians. The role of biomarkers has been poorly assessed. We evaluated whether copeptin and S100b protein (PS100b) assessment, alone or in combination, could rule out stroke in patients visiting EDs for dizziness.

Methods

We included patients 18 years of age or older, visiting the adult ED of a French university hospital for a new episode of dizziness evolving for less than 72 h. All patients underwent standardized physical examination (HINT [Head Impulse test, Nystagmus, test of skew deviation] maneuvers), copeptin and S-100b protein (PS100) measurement and injected brain imaging. Stroke diagnosis involved diffusion-weighted magnetic resonance imaging or, if not available, neurological examination and contrast brain CT scan compatible with the diagnosis.

Results

Of the 135 patients participating in the study, 13 (10%) had stroke. The sensitivity, specificity and positive and negative predictive values of copeptin/PS100 combination were 100% (95%CI, 77–100%), 48% (40–57%), 14% (11–27%) and 100% (94–100%), respectively. Values for copeptin alone were 77% (CI95% 0.50–0.91), 50% (CI95% 0.49–0.58), 14% (CI95% 0.08–0.24), 93% (CI95% 0.87–0.98), and for PS100 alone were 54% (CI95% 0.29–0.77), 97% (CI95% 0.92–0.99), 64% (CI95% 0.35–0.84), 95% (CI95% 0.90–0.98).

Conclusions

Absence of copeptin and PS100 elevation seems to ruling out the diagnosis of stroke in patients visiting the ED for a new episode of dizziness. These results need to be confirmed in a large-scale study.

Peripheral Vestibulopathy Presenting as Acute Vertigo and Spontaneous Nystagmus with Negative Video Head Impulse Test

OBJECTIVE

To analyze acute vertigo showing spontaneous nystagmus with negative video head impulse test (vHIT).

STUDY DESIGN

Retrospective chart analysis.

SETTING

Tertiary referral hospital.

SUBJECTS AND METHODS

Over 16 months, 155 patients were identified with acute vertigo with spontaneous nystagmus. Of these 155, 30 (19.4%) were enrolled in this study because they did not show gain loss or catch-up saccades in both sides of the horizontal vHIT. Results of vestibular function tests (videonystagmography, horizontal vHIT, caloric test, and cervical vestibular-evoked myogenic potential [cVEMP]) and pure tone audiometry were analyzed. For all cases, magnetic resonance imaging with diffusion-weighted imaging was checked.

RESULTS

Patients consisted of 17 with Ménière's disease and 7 with sudden sensorineural hearing loss with vertigo (SSNHL_V), and only 3 patients were finally diagnosed as having acute vascular stroke. Except for the loss of hearing on the lesion side, the direction of nystagmus or cVEMP asymmetry showed very different results. All 7 patients with SSNHL_V did not have canal paresis in the caloric test, but cVEMP amplitude was smaller on the lesion side for 6 patients.

CONCLUSIONS

For patients with acute vertigo presenting spontaneous nystagmus with negative horizontal vHIT, it is important not only to focus on the diagnosis of acute vascular stroke but also to evaluate hearing because of the high possibility of Ménière's disease or SSNHL_V.

Impact of artifacts on VOR gain measures by video-oculography in the acute vestibular syndrome

OBJECTIVE

The video head impulse test (HIT) measures vestibular function (vestibulo-ocular reflex [VOR] gain - ratio of eye to head movement), and, in principle, could be used to make a distinction between central and peripheral causes of vertigo. However, VOG recordings contain artifacts, so using unfiltered device data might bias the final diagnosis, limiting application in frontline healthcare settings such as the emergency department (ED). We sought to assess whether unfiltered data (containing artifacts) from a video-oculography (VOG) device have an impact on VOR gain measures in acute vestibular syndrome (AVS).

METHODS

This cross-sectional study compared VOG HIT results 'unfiltered' (standard device output) versus 'filtered' (artifacts manually removed) and relative to a gold standard final diagnosis (neuroimaging plus clinical follow-up) in 23 ED patients with acute dizziness, nystagmus, gait disturbance and head motion intolerance.

RESULTS

Mean VOR gain assessment alone (unfiltered device data) discriminated posterior inferior cerebellar artery (PICA) strokes from vestibular neuritis with 91% accuracy in AVS. Optimal stroke discrimination cut points were bilateral VOR gain >0.7099 (unfiltered data) versus >0.7041 (filtered data). For PICA stroke sensitivity and specificity, there was no clinically-relevant difference between unfiltered and filtered data-sensitivity for PICA stroke was 100% for both data sets and specificity was almost identical (87.5% unfiltered versus 91.7% filtered). More impulses increased gain precision.

CONCLUSIONS

The bedside HIT remains the single best method for discriminating between vestibular neuritis and PICA stroke in patients presenting AVS. Quantitative VOG HIT testing in the ED is associated with frequent artifacts that reduce precision but not accuracy. At least 10-20 properly-performed HIT trials per tested ear are recommended for a precise VOR gain estimate.

Vertigo and hearing loss

Symptoms referable to disorders affecting the inner ear and vestibulocochlear nerve (eighth cranial nerve) include dizziness, vertigo, tinnitus, and hearing loss, in various combinations. Similar symptoms may occur with involvement of the central nervous system, principally the brainstem and cerebellum, to which the vestibular and auditory systems are connected. Imaging choices should be tailored to patient symptoms and the clinical context. Computed tomography (CT) should be used primarily to assess bony structures. Magnetic resonance imaging (MRI) should be used primarily to assess soft-tissue structures. Vascular imaging by angiography or venography should be obtained when vascular lesions are suspected. No imaging should be obtained in patients with typical presentations of common peripheral vestibular or auditory disorders. In current clinical practice, neuroimaging is often overused, especially CT in the assessment of acute dizziness and vertigo in the emergency department. Despite low sensitivity for ischemic strokes, CT is often used to rule out neurologic causes. When ischemic stroke is the principal concern in acute vestibular presentations, imaging should almost always be by MRI with diffusion-weighted images, rather than CT. In this chapter, we describe recommended strategies for audiovestibular imaging based on patient symptoms and signs.

Acute dizziness in rural practice: Proposal of a diagnostic procedure

Acute dizziness is a frequent index symptom in the emergency department as well as in the rural practice office. Most acute dizziness, however, is not dangerous, but some types are highly dangerous. Clinical routine acute dizziness can be separated into frequent benign syndromes including benign paroxysmal positional vertigo (BPPV), vestibular neuritis, Meniθre's disease or vestibular migraine, and what is here referred to as the “white shark” of dizziness, i.e. a stroke in the posterior circulation or more rarely a tumor in the posterior fossa. A practical concept is presented to clarify most frequent acute dizziness syndromes using clinical and low budget methods.