What Does Head Impulse Testing Really Test?

To the Editor Walther et al ignore a fundamental rule of neurology: the pattern of the clinical or physiological deficit indicates the site and not the pathology of the lesion. This is the principle of neurological localization —there are textbooks written about it. The head impulse test, just like the caloric test, or the vestibular evoked myogenic potential, or an extensor plantar response can localize a lesion but reveal nothing about its pathology. For that, one needs to consider the history and results of ancillary investigations, say magnetic resonance imaging or spinal fluid test results. Impulsive testing can localize a vestibular deficit to 1 or more of the 6 semicircular canals but can show nothing about the cause of the deficit (Menière, or vestibular neuritis, or anterior inferior cerebellar artery ter ritory stroke, for example).
Source: JAMA Otolaryngology - Head and Neck Surgery - Category: ENT & OMF Source Type: research