Clinical Research Directory

Quantitative Eye Movement Measurements in Patients with Acute Vestibular Syndrome

BACKGROUND: A chief complaint of acute vertigo/dizziness is related to about 2.1-7.1% of all emergency department (ED) visits. About 25% of all patients with acute prolonged vertigo meeting diagnostic criteria of AVS (acute vestibular syndrome) suffer from a vertebrobasilar stroke and about 35% of these patients are initially missed. Differentiating dangerous central from more benign peripheral causes of AVS is essential. Subtle oculomotor paradigms such as HINTS (Head-Impulse, Nystagmus, Test-of-Skew) have been shown to detect central causes with high diagnostic accuracy, however, require sufficient training. Thus, identifying other bedside tests that can be reliably performed by frontline providers is essential to reduce misdiagnosis. WORKING HYPOTHESIS: By using additional oculomotor (saccades, pursuit) and pupillomotor parameters at the bedside or quantitatively, the diagnostic accuracy for distinguishing peripheral from central AVS causes can be further improved, especially in the setting when expertise for applying more sophisticated algorithms (HINTS(+), STANDING) is lacking. AIM 1: Detecting changes in oculomotor and pupillomotor responses in acutely dizzy patients and characterizing the spectrum of abnormalities in peripheral and central AVS. AIM 2: Comparing different composite oculomotor-/pupillomotor scores to identify those scores with the highest diagnostic accuracy at the bedside and quantitatively. AIM 3: Comparing the diagnostic accuracy of bedside and quantitative oculomotor and pupillomotor testing in AVS- identifying potential limitations of bedside testing. METHODS: To assess oculomotor and pupillomotor responses in patients with peripheral or central AVS and healthy controls (25 participants each) at the bedside and quantitatively by use of a Pioneer research eye tracker (PRET) system and to compare the diagnostic accuracy of individual and composite responses. EXPECTED VALUE OF THE PROJECT: The proposed project will shed more light on the value of different examination techniques in AVS for distinguishing peripheral from central causes. This is achieved by investigating oculomotor and pupillomotor parameters obtained at the bedside and quantitatively in the acute stage and at follow-up. The insights gained will likely have a direct impact on diagnostic accuracy and thus on future strategies how to evaluate acutely dizzy patients in the ED. Eventually, this may reduce the rate of misdiagnosis and may improve patients' outcome.

Diagnostic Work up and Management of Acute Onset Vertigo

Incidence: Dizziness or vertigo is a very prevalent complaint in the general population, and a common reason for seeking medical attention. In Denmark, 20-30 % have experienced dizziness/vertigo to a degree that has led to disability, sick leave, or medical contact(1). In the United States, dizziness is estimated to account for partly 2.6-4.4 million visits to emergency departments (EDs) each year, partly 4 % of main symptoms in patients admitted to EDs (2). In Germany, the estimated prevalence of dizziness is 20-30 % with an annual incidence about 11 % (3). Terminology and definition: Dizziness or vertigo is not a disease itself but rather a symptom of various underlying disorders. Thus, vestibular, neurological, cardiovascular, metabolic, and psychiatric diseases may be associated with dizziness/vertigo as well as medical side effects. Patients (and professionals) often use the two terms dizziness and vertigo synonymously, which may cause some confusion in the choice of diagnostics. Vertigo is characteristic for vestibular disorders and is defined as sensation of self-motion when no self-motion occurs, or sensation of distorted self-motion during an otherwise normal head movement, whereas dizziness is a feeling of more general unsteadiness. 1. Is implementation of HINTS and v-HIT in an ED able to reduce the number of undiagnosed and misdiagnosed cases of acute onset vertigo as well as diagnostic delay ? 2. What are the effects of immediate and systematic balance training in case of acute vestibular diseases ? 3. What is the cost-effectiveness of implementation of HINTS and v-HIT as up front diagnostics, and systematic balance training in patients with acute vestibular diseases ?