Question
What is the head thrust? Is it the same as head shake?
Answer
The head thrust test and the head shake tests are not the same tests.
The Halmaygi head thrust test is a test of unilateral vestibulo-ocular reflex gain and is a passive head movement test. That is, the patient does not turn his or her head themselves, rather the examiner moves the head. The patient is instructed to view a distant object and to keep their visual focus on that object at all times. The examiner suddenly turns the patient's head to the right or left rapidly through a small arc. The head is then turned to the opposite side. If the VOR gain is normal, or near normal, on the side of the direction of the movement, the eyes will remain on the visual target, or another way to think of it is that the eyes remain fixed in space. However,if the patient exhibits saccadic corrections of the eye (to maintain visual lock on the object), reduced VOR gain is suggested on the side of the movement is suggested.
The head shake test is an active movement test, that is, the patient moves their head on their own. Start with the patient looking straight ahead and observe if there is any spontaneous nystagmus. This can be done with the patient wearing Frenzel lenses, hooked up to an electrode based ENG, or while wearing the video goggles of an infra-red VNG system. Then the patient is asked to shake their head as vigorously as they can from side-to-side, as in saying ''no'' for 20 seconds. If nystagmus is observed after the cessation of the head shaking, and there was no spontaneous nystagmus observed in the pre-head shake condition, an otherwise compensated peripheral lesion has become evident.
Respectfully,
Henry P. Trahan, Au.D.
Henry P. Trahan, Au.D.
Asst. Professor of Audiology
The Arizona School of Health Sciences
5850 E. Still Circle
Mesa, AZ 85206
Dr. Trahan is a graduate of LSUHSC, Masters of Communicative Disorders. Graduate of the University of Florida, Doctor of Audiology
Currently:
Assistant Professor of Audiology at the Arizona School of Health Sciences. Lead faculty for the 4 year AuD Residential program. Currently also teaching Vestibular Assessment Procedures and Balance Remediation in the ASHS AuD Distance Ed AuD program.
Past:
20 years private practice with significant involvement in assessment of vestibular disorders and vestibular rehabilitation.
Conducted numerous workshops and presentations in regards to Audiologists in private practice adding Vestibular Assessment and Vestibular Rehabilitation to their practices.