Georgios Mantokoudis

Quantitative video-oculography to help diagnose stroke in acute vertigo and dizziness: Toward an ECG for the eyes

Background and Purpose— Strokes can be distinguished from benign peripheral causes of acute vestibular syndrome using bedside oculomotor tests (head impulse test, nystagmus, test-of-skew). Using head impulse test, nystagmus, test-of-skew is more sensitive and less costly than early magnetic resonance imaging for stroke diagnosis in acute vestibular syndrome but requires expertise not routinely available in emergency departments. We sought to begin standardizing the head impulse test, nystagmus, test-of-skew diagnostic approach for eventual emergency department use through the novel application of a portable video-oculography device measuring vestibular physiology in real time. This approach is conceptually similar to ECG to diagnose acute cardiac ischemia. Methods— Proof-of-concept study (August 2011 to June 2012). We recruited adult emergency department patients with acute vestibular syndrome defined as new, persistent vertigo/dizziness, nystagmus, and (1) nausea/vomiting, (2) head motion intolerance, or (3) new gait unsteadiness. We recorded eye movements, including quantitative horizontal head impulse testing of vestibulo-ocular-reflex function. Two masked vestibular experts rated vestibular findings, which were compared with final radiographic gold-standard diagnoses. Masked neuroimaging raters determined stroke or no stroke using magnetic resonance imaging of the brain with diffusion-weighted imaging obtained 48 hours to 7 days after symptom onset. Results— We enrolled 12 consecutive patients who underwent confirmatory magnetic resonance imaging. Mean age was 61 years (range 30–73), and 10 were men. Expert-rated video-oculography–based head impulse test, nystagmus, test-of-skew examination was 100% accurate (6 strokes, 6 peripheral vestibular). Conclusions— Device-based physiological diagnosis of vertebrobasilar stroke in acute vestibular syndrome should soon be possible. If confirmed in a larger sample, this bedside eye ECG approach could eventually help fulfill a critical need for timely, accurate, efficient diagnosis in emergency department patients with vertigo or dizziness who are at high risk for stroke.

Rising annual costs of dizziness presentations to U.S. emergency departments.

OBJECTIVES Dizziness and vertigo account for roughly 4% of chief symptoms in the emergency department (ED). Little is known about the aggregate costs of ED evaluations for these patients. The authors sought to estimate the annual national costs associated with ED visits for dizziness. METHODS This cost study of adult U.S. ED visits presenting with dizziness or vertigo combined public-use ED visit data (1995 to 2009) from the National Hospital Ambulatory Medical Care Survey (NHAMCS) and cost data (2003 to 2008) from the Medical Expenditure Panel Survey (MEPS). We calculated total visits, test utilization, and ED diagnoses from NHAMCS. Diagnosis groups were defined using the Healthcare Cost and Utilization Projects Clinical Classifications Software (HCUP-CCS). Total visits and the proportion undergoing neuroimaging for future years were extrapolated using an autoregressive forecasting model. The average ED visit cost-per-diagnosis-group from MEPS were calculated, adjusting to 2011 dollars using the Hospital Personal Health Care Expenditures price index. An overall weighted mean across the diagnostic groups was used to estimate total national costs. Year 2011 data are reported in 2011 dollars. RESULTS The estimated number of 2011 US ED visits for dizziness or vertigo was 3.9 million (95% confidence interval [CI] = 3.6 to 4.2 million). The proportion undergoing diagnostic imaging by computed tomography (CT), magnetic resonance imaging (MRI), or both in 2011 was estimated to be 39.9% (39.4% CT, 2.3% MRI). The mean per-ED-dizziness-visit cost was

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

1,004 in 2011 dollars. The total extrapolated 2011 national costs were

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

3.9 billion. HCUP-CCS key diagnostic groups for those presenting with dizziness and vertigo included the following (fraction of dizziness visits, cost-per-ED-visit, attributable annual national costs): otologic/vestibular (25.7%;

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

768;

Early adaptation and compensation of clinical vestibular responses after unilateral vestibular deafferentation surgery.

757 million), cardiovascular (16.5%,

Ear canal cholesteatoma: meta-analysis of clinical characteristics with update on classification, staging and treatment.

1,489;

Vestibular signs of thiamine deficiency during the early phase of suspected Wernicke encephalopathy

941 million), and cerebrovascular (3.1%;

Internet Video Telephony Allows Speech Reading by Deaf Individuals and Improves Speech Perception by Cochlear Implant Users

1059;

Speech perception benefits of internet versus conventional telephony for hearing-impaired individuals.

127 million). Neuroimaging was estimated to account for about 12% of the total costs for dizziness visits in 2011 (CT scans