To the Editor Walther et al1 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.2 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 (Ménière, or vestibular neuritis, or anterior inferior cerebellar artery territory stroke, for example).
Identify all potential conflicts of interest that might be relevant to your comment.
Conflicts of interest comprise financial interests, activities, and relationships within the past 3 years including but not limited to employment, affiliation, grants or funding, consultancies, honoraria or payment, speaker's bureaus, stock ownership or options, expert testimony, royalties, donation of medical equipment, or patents planned, pending, or issued.
Err on the side of full disclosure.
If you have no conflicts of interest, check "No potential conflicts of interest" in the box below. The information will be posted with your response.
Not all submitted comments are published. Please see our commenting policy for details.
Curthoys IS, Halmagyi GM. What Does Head Impulse Testing Really Test? JAMA Otolaryngol Head Neck Surg. 2019;145(11):1080. doi:10.1001/jamaoto.2019.2788
Coronavirus Resource Center
Customize your JAMA Network experience by selecting one or more topics from the list below.
Create a personal account or sign in to: