HINTS outperforms ABCD2 to screen for stroke in acute continuous vertigo and dizziness

Stroke risk stratification in acute dizziness presentations: A prospective imaging-based study

OBJECTIVE

To estimate the ability of bedside information to risk stratify stroke in acute dizziness presentations.

METHODS

Surveillance methods were used to identify patients with acute dizziness and nystagmus or imbalance, excluding those with benign paroxysmal positional vertigo, medical causes, or moderate to severe neurologic deficits. Stroke was defined as acute infarction or intracerebral hemorrhage on a clinical or research MRI performed within 14 days of dizziness onset. Bedside information comprised history of stroke, the ABCD(2) score (age, blood pressure, clinical features, duration, and diabetes), an ocular motor (OM)-based assessment (head impulse test, nystagmus pattern [central vs other], test of skew), and a general neurologic examination for other CNS features. Multivariable logistic regression was used to determine the association of the bedside information with stroke. Model calibration was assessed using low (<5%), intermediate (5% to <10%), and high (≥10%) predicted probability risk categories.

RESULTS

Acute stroke was identified in 29 of 272 patients (10.7%). Associations with stroke were as follows: ABCD(2) score (continuous) (odds ratio [OR] 1.74; 95% confidence interval [CI] 1.20-2.51), any other CNS features (OR 2.54; 95% CI 1.06-6.08), OM assessment (OR 2.82; 95% CI 0.96-8.30), and prior stroke (OR 0.48; 95% CI 0.05-4.57). No stroke cases were in the model's low-risk probability category (0/86, 0%), whereas 9 were in the moderate-risk category (9/94, 9.6%) and 20 were in the high-risk category (20/92, 21.7%).

CONCLUSION

In acute dizziness presentations, the combination of ABCD(2) score, general neurologic examination, and a specialized OM examination has the capacity to risk-stratify acute stroke on MRI.

Emergency Physician Attitudes, Preferences, and Risk Tolerance for Stroke as a Potential Cause of Dizziness Symptoms

Introduction

We evaluated emergency physicians’ (EP) current perceptions, practice, and attitudes towards evaluating stroke as a cause of dizziness among emergency department patients.

Methods

We administered a survey to all EPs in a large integrated healthcare delivery system. The survey included clinical vignettes, perceived utility of historical and exam elements, attitudes about the value of and requisite post-test probability of a clinical prediction rule for dizziness. We calculated descriptive statistics and post-test probabilities for such a clinical prediction rule.

Results

The response rate was 68% (366/535). Respondents’ median practice tenure was eight years (37% female, 92% emergency medicine board certified). Symptom quality and typical vascular risk factors increased suspicion for stroke as a cause of dizziness. Most respondents reported obtaining head computed tomography (CT) (74%). Nearly all respondents used and felt confident using cranial nerve and limb strength testing. A substantial minority of EPs used the Epley maneuver (49%) and HINTS (head-thrust test, gaze-evoked nystagmus, and skew deviation) testing (30%); however, few EPs reported confidence in these tests’ bedside application (35% and 16%, respectively). Respondents favorably viewed applying a properly validated clinical prediction rule for assessment of immediate and 30-day stroke risk, but indicated it would have to reduce stroke risk to <0.5% to be clinically useful.

Conclusion

EPs report relying on symptom quality, vascular risk factors, simple physical exam elements, and head CT to diagnose stroke as the cause of dizziness, but would find a validated clinical prediction rule for dizziness helpful. A clinical prediction rule would have to achieve a 0.5% post-test stroke probability for acceptability.

The effect of intra-tympanic dexamethasone on the vestibular function in patients with recurrent vertigo

CONCLUSION

The low clinical efficacy of the treatment for patients included in this work correlates with no noticeable effect on the vestibular function.

OBJECTIVE

To assess follow-up in patients with idiopathic and secondary Ménière's disease after treatment with intra-tympanic dexamethasone and correlate clinical findings with changes in the vestibular-ocular reflex elicited after stimulation of each of the six semicircular canals.

METHODS

This is a single center retrospective review of patients presenting the clinical symptomatology of Meniérè's disease treated with intra-tympanic dexamethasone. An audiometric evaluation was performed in each patient before and after treatment. The study cohort was divided into two groups: those evaluated after a short period of time and after a long period of time.

RESULTS

The study included 30 patients, mean age = 61 years. Differences in mean pure-tone average before and after treatment were non-significant for both treated (0.61 dB, p = 0.723) and untreated (0.59 dB, p = 0.609) ears. Vestibular-ocular reflex gain averages in the treated ear after treatment were 0.73 (superior semicircular canal), 0.86 (horizontal semicircular canal), and 0.69 (posterior semicircular canal). The gain did not vary significantly in the Superior (p = 0.194), the Horizontal (p = 0.646), or the Posterior Semicircular Canal (p = 0.820). Similar were obtained for the untreated ear.

VOR gain by head impulse video-oculography differentiates acute vestibular neuritis from stroke

OBJECTIVE

Vestibular neuritis is often mimicked by stroke (pseudoneuritis). Vestibular eye movements help discriminate the two conditions. We report vestibulo-ocular reflex (VOR) gain measures in neuritis and stroke presenting acute vestibular syndrome (AVS).

METHODS

Prospective cross-sectional study of AVS (acute continuous vertigo/dizziness lasting >24 h) at two academic centers. We measured horizontal head impulse test (HIT) VOR gains in 26 AVS patients using a video HIT device (ICS Impulse). All patients were assessed within 1 week of symptom onset. Diagnoses were confirmed by clinical examinations, brain magnetic resonance imaging with diffusion-weighted images, and follow-up. Brainstem and cerebellar strokes were classified by vascular territory-posterior inferior cerebellar artery (PICA) or anterior inferior cerebellar artery (AICA).

RESULTS

Diagnoses were vestibular neuritis (n = 16) and posterior fossa stroke (PICA, n = 7; AICA, n = 3). Mean HIT VOR gains (ipsilesional [standard error of the mean], contralesional [standard error of the mean]) were as follows: vestibular neuritis (0.52 [0.04], 0.87 [0.04]); PICA stroke (0.94 [0.04], 0.93 [0.04]); AICA stroke (0.84 [0.10], 0.74 [0.10]). VOR gains were asymmetric in neuritis (unilateral vestibulopathy) and symmetric in PICA stroke (bilaterally normal VOR), whereas gains in AICA stroke were heterogeneous (asymmetric, bilaterally low, or normal). In vestibular neuritis, borderline gains ranged from 0.62 to 0.73. Twenty patients (12 neuritis, six PICA strokes, two AICA strokes) had at least five interpretable HIT trials (for both ears), allowing an appropriate classification based on mean VOR gains per ear. Classifying AVS patients with bilateral VOR mean gains of 0.70 or more as suspected strokes yielded a total diagnostic accuracy of 90%, with stroke sensitivity of 88% and specificity of 92%.

CONCLUSION

Video HIT VOR gains differ between peripheral and central causes of AVS. PICA strokes were readily separated from neuritis using gain measures, but AICA strokes were at risk of being misclassified based on VOR gain alone.

Compensatory saccades benefit from prediction during head impulse testing in early recovery from vestibular deafferentation

The head impulse test (HIT) can identify a deficient vestibulo-ocular reflex (VOR) by the compensatory saccade (CS) generated once the head stops moving. The inward HIT is considered safer than the outward HIT, yet might have an oculomotor advantage given that the subject would presumably know the direction of head rotation. Here, we compare CS latencies following inward (presumed predictable) and outward (more unpredictable) HITs after acute unilateral vestibular nerve deafferentation. Seven patients received inward and outward HITs delivered at six consecutive postoperative days (POD) and again at POD 30. All head impulses were recorded by portable video-oculography. CS included those occurring during (covert) or after (overt) head rotation. Inward HITs included mean CS latencies (183.48 ms ± 4.47 SE) that were consistently shorter than those generated during outward HITs in the first 6 POD (p = 0.0033). Inward HITs induced more covert saccades compared to outward HITs, acutely. However, by POD 30 there were no longer any differences in latencies or proportions of CS and direction of head rotation. Patients with acute unilateral vestibular loss likely use predictive cues of head direction to elicit early CS to keep the image centered on the fovea. In acute vestibular hypofunction, inwardly applied HITs may risk a preponderance of covert saccades, yet this difference largely disappears within 30 days. Advantages of inwardly applied HITs are discussed and must be balanced against the risk of a false-negative HIT interpretation.

Acute Diagnosis and Management of Stroke Presenting Dizziness or Vertigo

Stroke involving the brainstem and cerebellum frequently presents acute vestibular syndrome. Although vascular vertigo is known to usually accompany other neurologic symptoms and signs, isolated vertigo from small infarcts involving the cerebellum or brainstem has been increasingly recognized. Bedside neuro-otologic examination can reliably differentiate acute vestibular syndrome due to stroke from more benign inner ear disease. Sometimes acute isolated audiovestibular loss may herald impending infarction in the territory of the anterior inferior cerebellar artery. Accurate identification of isolated vascular vertigo is very important because misdiagnosis of acute stroke may result in significant morbidity and mortality.

Can emergency physicians accurately and reliably assess acute vertigo in the emergency department?

OBJECTIVE

To validate a clinical diagnostic tool, used by emergency physicians (EPs), to diagnose the central cause of patients presenting with vertigo, and to determine interrater reliability of this tool.

METHODS

A convenience sample of adult patients presenting to a single academic ED with isolated vertigo (i.e. vertigo without other neurological deficits) was prospectively evaluated with STANDING (SponTAneousNystagmus, Direction, head Impulse test, standiNG) by five trained EPs. The first step focused on the presence of spontaneous nystagmus, the second on the direction of nystagmus, the third on head impulse test and the fourth on gait. The local standard practice, senior audiologist evaluation corroborated by neuroimaging when deemed appropriate, was considered the reference standard. Sensitivity and specificity of STANDING were calculated. On the first 30 patients, inter-observer agreement among EPs was also assessed.

RESULTS

Five EPs with limited experience in nystagmus assessment volunteered to participate in the present study enrolling 98 patients. Their average evaluation time was 9.9 ± 2.8 min (range 6-17). Central acute vertigo was suspected in 16 (16.3%) patients. There were 13 true positives, three false positives, 81 true negatives and one false negative, with a high sensitivity (92.9%, 95% CI 70-100%) and specificity (96.4%, 95% CI 93-38%) for central acute vertigo according to senior audiologist evaluation. The Cohen's kappas of the first, second, third and fourth steps of the STANDING were 0.86, 0.93, 0.73 and 0.78, respectively. The whole test showed a good inter-observer agreement (k = 0.76, 95% CI 0.45-1).

CONCLUSIONS

In the hands of EPs, STANDING showed a good inter-observer agreement and accuracy validated against the local standard of care.

Vestibular evoked myogenic potentials (VEMPs) in central neurological disorders

Several types of acoustic stimulation (i.e. tone bursts or clicks), bone-conducted vibration, forehead taps, and galvanic stimulation elicit myogenic potentials. These can be recorded in cervical and ocular muscles, the so called vestibular evoked myogenic potentials (VEMPs). The cervical VEMP (cVEMP) resembles the vestibulo-collic reflex and the responses can be recorded from the ipsilateral sternocleidomastoid muscle. The ocular VEMP resembles the vestibulo-ocular reflex and can be recorded from extra-ocular muscles by a surface electrode beneath the contralateral infraorbital margin. Initially, the literature concerning VEMPs was limited to peripheral vestibular disorders, however, the field of VEMP testing is rapidly expanding, with an increasing focus on central neurological disorders. The current literature concerning VEMP abnormalities in central neurological disorders is critically reviewed, especially regarding the methodological aspects in relation to quality as well as the clinical interpretation of the VEMP results. Suggestions for further research are proposed as well as some clinically useful indications.

Quantifying the vestibulo-ocular reflex with video-oculography: nature and frequency of artifacts

Video-oculography devices are now used to quantify the vestibulo-ocular reflex (VOR) at the bedside using the head impulse test (HIT). Little is known about the impact of disruptive phenomena (e.g. corrective saccades, nystagmus, fixation losses, eye-blink artifacts) on quantitative VOR assessment in acute vertigo. This study systematically characterized the frequency, nature, and impact of artifacts on HIT VOR measures. From a prospective study of 26 patients with acute vestibular syndrome (16 vestibular neuritis, 10 stroke), we classified findings using a structured coding manual. Of 1,358 individual HIT traces, 72% had abnormal disruptive saccades, 44% had at least one artifact, and 42% were uninterpretable. Physicians using quantitative recording devices to measure head impulse VOR responses for clinical diagnosis should be aware of the potential impact of disruptive eye movements and measurement artifacts.

Low HDL cholesterol is correlated to the acute ischemic stroke with diabetes mellitus

Background

To clarify the role of lipid composition in the occurrence of acute ischemic stroke (AIS) with diabetes mellitus (DM) and its influence factors.

Methods

Data was collected from the patients hospitalization in Affiliated Drum Tower Hospital of Nanjing University Medical School from October 2008 to May 2012, which included AIS and non-AIS consist of transient ischemic attack (TIA) and Vertigo or dizzy. Lipid and other risk factors including blood glucose (BG), uric acid (UA), hypertension, DM and atrial fibrillation (AF) were investigated in relation to occurrence of AIS.

Results

The level of high density lipoprotein (HDL) cholesterol was decreased obviously in the DM group compared to the non-DM group and low level of HDL cholesterol was prevalent in the AIS patients with DM. logistic regression demonstrated that decreased HDL cholesterol was correlated to the AIS with DM, not all AIS, and the relative risk of ischemic stroke in low HDL cholesterol level group was 2.113 (95% CI = 1.191-3.749, P = 0.011) compared to the high level group. Furthermore, age has the obviously impact on it. HDL cholesterol was correlated to the AIS with DM just in the populations of aged ≦70 years (OR = 0.192, P = 0.000), low level of HDL cholesterol had more high risk of ischemic stroke than that in the high level group (OR = 6.818, P = 0.002).

Conclusion

Decreased HDL cholesterol was correlated to the occurrence of AIS with DM, especially in the populations of aged ≦70 years.

The vestibulo-ocular reflex assessment in patients with Ménière's disease: examining all semicircular canals

Abstract Conclusion: The distribution of abnormal results is not uniform between different canals in each patient; the most frequent gain reduction is obtained for the posterior canal. Gain reduction reflects the disease duration and amount of hearing loss.

OBJECTIVE

To test the hypothesis that the vestibulo-ocular reflex (VOR) evoked after stimulation of each semicircular canal behaves in a different manner in patients with unilateral definite Ménière's disease.

METHODS

We studied the VOR evoked by rapid head-impulses in the plane of the 6 semicircular canals in 36 patients. It was evaluated with a video system that analyzes the head and eye velocity and the gain was the objective measure.

RESULTS

In 12 (33.3%) patients the examination of both ears was normal for all the semicircular canals, in 12 patients the results from the affected ear were abnormal in at least 1 of the semicircular canals, in 11 (30.5%) patients the results were abnormal in at least 1 of the semicircular canals in both the affected and unaffected ears, and in 1 (2.9%) patient the results were abnormal only in the unaffected ear. The most frequent abnormal result was obtained from the posterior canal of the affected ear and from the coupled superior canal of the unaffected ear. The distribution of abnormal findings was dependent on the disease duration and hearing loss.

Head impulse gain and saccade analysis in pontine-cerebellar stroke and vestibular neuritis

OBJECTIVE

We sought to quantify and compare angular vestibulo-ocular reflex (aVOR) gain and compensatory saccade properties elicited by the head impulse test (HIT) in pontine-cerebellar stroke (PCS) and vestibular neuritis (VN).

METHODS

Horizontal HIT was recorded ≤7 days from vertigo onset with dual-search coils in 33 PCS involving the anterior inferior, posterior inferior, and superior cerebellar arteries (13 AICA, 17 PICA, 3 SCA) confirmed by MRI and 20 VN. We determined the aVOR gain and asymmetry, and compensatory overt saccade properties including amplitude asymmetry and cumulative amplitude (ipsilesional trials [I]; contralesional trials [C]).

RESULTS

The aVOR gain (normal: 0.96; asymmetry = 2%) was bilaterally reduced, greater in AICA (I = 0.39, C = 0.57; asymmetry = 20%) than in PICA/SCA strokes (I = 0.75, C = 0.74; asymmetry = 7%), in contrast to the unilateral deficit in VN (I = 0.22, C = 0.76; asymmetry = 54%). Cumulative amplitude (normal: 1.1°) was smaller in AICA (I = 4.2°, C = 3.0°) and PICA/SCA strokes (I = 2.1°, C = 3.0°) compared with VN (I = 8.5°, C = 1.3°). Amplitude asymmetry in AICA and PICA/SCA strokes was comparable, but favored the contralesional side in PICA/SCA strokes and the ipsilesional side in VN. Saccade asymmetry <61% was found in 97% of PCS and none of VN. Gain asymmetry <40% was found in 94% of PCS and 10% of VN.

CONCLUSION

HIT gains and compensatory saccades differ between PCS and VN. VN was characterized by unilateral gain deficits with asymmetric large saccades, AICA stroke by more symmetric bilateral gain reduction with smaller saccades, and PICA stroke by contralesional gain bias with the smallest saccades. Saccade and gain asymmetry should be investigated further in future diagnostic accuracy studies.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that aVOR testing accurately distinguishes patients with PCS from VN (sensitivity 94%-97%, specificity 90%-100%).

Recent onset disequilibrium mimicking acute vestibulopathy in early multiple sclerosis

The differential diagnosis of patients with acute unilateral vestibulopathy rests in the proper clinical assessment and use of selected tests of vestibular function. In case of a central nervous system lesion as in Multiple Sclerosis, the case shown here, it is of particular importance to observe congruency between severity of symptoms and signs and, of topographic diagnosis. We report a case of a 37-year-old woman with recent onset disequilibrium that after careful analysis of the different test results several incongruences were found; this prompted a radiological study that provided the clue to diagnosis. After treatment the patient recovered completely not only clinically but also in vestibular deficit.

Small strokes causing severe vertigo: frequency of false-negative MRIs and nonlacunar mechanisms

OBJECTIVE

Describe characteristics of small strokes causing acute vestibular syndrome (AVS).

METHODS

Ambispective cross-sectional study of patients with AVS (acute vertigo or dizziness, nystagmus, nausea/vomiting, head-motion intolerance, unsteady gait) with at least one stroke risk factor from 1999 to 2011 at a single stroke referral center. Patients underwent nonquantitative HINTS "plus" examination (head impulse, nystagmus, test-of-skew plus hearing), neuroimaging to confirm diagnoses (97% by MRI), and repeat MRI in those with initially normal imaging but clinical signs of a central lesion. We identified patients with diffusion-weighted imaging (DWI) strokes ≤10 mm in axial diameter.

RESULTS

Of 190 high-risk AVS presentations (105 strokes), we found small strokes in 15 patients (median age 64 years, range 41-85). The most common vestibular structure infarcted was the inferior cerebellar peduncle (73%); the most common stroke location was the lateral medulla (60%). Focal neurologic signs were present in only 27%. The HINTS "plus" battery identified small strokes with greater sensitivity than early MRI-DWI (100% vs 47%, p < 0.001). False-negative initial MRIs (6-48 hours) were more common with small strokes than large strokes (53% [n = 8/15] vs 7.8% [n = 7/90], p < 0.001). Nonlacunar stroke mechanisms were responsible in 47%, including 6 vertebral artery occlusions or dissections.

CONCLUSIONS

Small strokes affecting central vestibular projections can present with isolated AVS. The HINTS "plus" hearing battery identifies these patients with greater accuracy than early MRI-DWI, which is falsely negative in half, up to 48 hours after onset. We found nonlacunar mechanisms in half, suggesting greater risk than might otherwise be assumed for patients with such small infarctions.

Stroke risk after nonstroke emergency department dizziness presentations: a population-based cohort study

OBJECTIVE

Acute stroke is a serious concern in emergency department (ED) dizziness presentations. Prior studies, however, suggest that stroke is actually an unlikely cause of these presentations. Lacking are data on short- and long-term follow-up from population-based studies to establish stroke risk after presumed nonstroke ED dizziness presentations.

METHODS

From May 8, 2011 to May 7, 2012, patients ≥45 years of age presenting to EDs in Nueces County, Texas, with dizziness, vertigo, or imbalance were identified, excluding those with stroke as the initial diagnosis. Stroke events after the ED presentation up to October 2, 2012 were determined using the BASIC (Brain Attack Surveillance in Corpus Christi) study, which uses rigorous surveillance and neurologist validation. Cumulative stroke risk was calculated using Kaplan-Meier estimates.

RESULTS

A total of 1,245 patients were followed for a median of 347 days (interquartile range [IQR] = 230-436 days). Median age was 61.9 years (IQR = 53.8-74.0 years). After the ED visit, 15 patients (1.2%) had a stroke. Stroke risk was 0.48% (95% confidence interval [CI] = 0.22-1.07%) at 2 days, 0.48% (95% CI = 0.22-1.07%) at 7 days, 0.56% (95% CI = 0.27-1.18%) at 30 days, 0.56% (95% CI = 0.27-1.18%) at 90 days, and 1.42% (95% CI = 0.85-2.36%) at 12 months.

INTERPRETATION

Using rigorous case ascertainment and outcome assessment in a population-based design, we found that the risk of stroke after presumed nonstroke ED dizziness presentations is very low, supporting a nonstroke etiology to the overwhelming majority of original events. High-risk subgroups likely exist, however, because most of the 90-day stroke risk occurred within 2 days. Vascular risk stratification was insufficient to identify these cases.

Missed diagnosis of stroke in the emergency department: a cross-sectional analysis of a large population-based sample

Background

Some cerebrovascular events are not diagnosed promptly, potentially resulting in death or disability from missed treatments. We sought to estimate the frequency of missed stroke and examine associations with patient, emergency department (ED), and hospital characteristics.

Methods

Cross-sectional analysis using linked inpatient discharge and ED visit records from the 2009 Healthcare Cost and Utilization Project State Inpatient Databases and 2008–2009 State ED Databases across nine US states. We identified adult patients admitted for stroke with a treat-and-release ED visit in the prior 30 days, considering those given a non-cerebrovascular diagnosis as probable (benign headache or dizziness diagnosis) or potential (any other diagnosis) missed strokes.

Results

There were 23,809 potential and 2243 probable missed strokes representing 12.7% and 1.2% of stroke admissions, respectively. Missed hemorrhages (n = 406) were linked to headache while missed ischemic strokes (n = 1435) and transient ischemic attacks (n = 402) were linked to headache or dizziness. Odds of a probable misdiagnosis were lower among men (OR 0.75), older individuals (18–44 years [base]; 45–64:OR 0.43; 65–74:OR 0.28; ≥ 75:OR 0.19), and Medicare (OR 0.66) or Medicaid (OR 0.70) recipients compared to privately insured patients. Odds were higher among Blacks (OR 1.18), Asian/Pacific Islanders (OR 1.29), and Hispanics (OR 1.30). Odds were higher in non-teaching hospitals (OR 1.45) and low-volume hospitals (OR 1.57).

Conclusions

We estimate 15,000–165,000 misdiagnosed cerebrovascular events annually in US EDs, disproportionately presenting with headache or dizziness. Physicians evaluating these symptoms should be particularly attuned to the possibility of stroke in younger, female, and non-White patients.