Complete Heart Block Complicating the Head Impulse Test

Abstract

Background: Symptoms of acute vestibular syndrome include dizziness, nausea, vomiting, and postural instability. The cause may be a peripheral or central lesion. Distinguishing between these two causes is critical because the treatments differ completely. One bedside test to help make this distinction clinically is the head impulse test (HIT), sometimes called the head thrust test.

Triple Test as Predictive Screen for Unilateral Weakness on Caloric Testing in Routine Practice

“…A normal HIT result in patients suspected of having a peripheral vestibulopathy should always prompt consideration of a central lesion (10,24). Despite the abruptness of the head impulse movement, the test itself hardly ever causes problems: to date there has been just one case report of a vagal reaction as a complication of the HIT (25).…”

Medical and Nonstroke Neurologic Causes of Acute, Continuous Vestibular Symptoms

“…Furthermore, the high vagal tone that accompanies some vestibular disorders can provoke bradyarrhythmias in susceptible individuals, including during the examination. 111 Nevertheless, although they may be quite disabling to patients during the acute illness phase, diseases classified here as Benign or Less Urgent Causes rarely produce severe, irreversible morbidity or mortality (unlike their dangerous counterparts). b The frequency of labyrinthine infarction is difficult to estimate given that the current reference standard test for confirming the diagnosis (ie, autopsy with temporal bone histology) is rarely performed.…”

Medical and Psychiatric Causes of Episodic Vestibular Symptoms

“…In one case, the head-impulse test precipitated vagally mediated complete heart block in a patient with a recent, pre-existing peripheral vertigo presentation. 36 In another case, a patient initially diagnosed with paroxysmal positional vertigo was finally noted to have neurally mediated presyncope secondary to bradycardia on a longer-term event monitor despite initial extensive neurology and cardiology evaluations. 37 The patient exhibited an intense fear of turning onto his right side, and therefore, positional testing never provoked nystagmus.…”