The head impulse or head thrust test was first described by Halmagyi and Curthoys in 1988. It has acquired an increasingly important place in the clinical examination of the vertigo patient. It detects severe unilateral loss of semicircular canal (SCC) function clinically; it is more sensitive and specific than the traditional Romberg and similar tests; and it is particularly important in the emergency unit, where it can distinguish between vestibular neuritis and cerebellar infarction, which can both generate similar symptoms suggesting an initial attack of severe acute vertigo.The result of the head thrust test is definitely normal in a patient with a cerebellar infarction but abnormal in a patient with vestibular neuronitis.
