[Curthoys and Halmagyi Head Impulse test: an analytical device]

Described in 1988 by Curthoys and Halmagyi, the Head Impulse test enables checking the individual response of each of the six semicircular canals to fast head movements within less than one minute. Interpretation of test results requires careful clinical observation of the eye/head synchronism. But, due to the very short duration of the phenomenon, such synchronism is often difficult to confirm. This is so difficult that, sixteen years after its first description, the test is still rarely performed in daily practice.

We describe hereafter a device which allows confirmation of the positive or negative test results for each of the six canals without increasing test duration.

A high resolution and high light sensitivity video camera located in front of the patient's face at a distance of 80 cm is connected to a computer for automatic image analysis.

With this device, the practitioner can confirm a positive test by simple observation on the videooculocephaloscope (HIT scope) and record an image for later reference. With videooculocephalography (HIT graph), movements can be recorded for analysis to quantify the deficit of each semicircular canal.