Does the ability to detect covert saccades eliminate the need to do a MRI of the cerebellum in case of monosymptomatic dizzines ?
About your Head Impulse Test equipment. In case of a vestibular neuritis in acute phase. Can you rely on the Head Impulse Test equipment so strongly, that when you see covert saccades on the machine you don’t have to do a MRI of the cerebellum in case of monosymptomatic dizziness?? To rule out cerebellar infarct.
Jens H. Wanscher, Odense Universityhospital
Michael Halmagyi says:
..a great question
like every other rule-out test in medicine – about 95% accuracy- you can have a positive head impulse test with a cerebellar infarct when there is an anterior inferior cerebellar artery territory infarct sparing the brainstem but involving the cerebellum and the inner ear (via the internal auditory artery)
this is so rare that it usually ends up as a case report
and if course if you test hearing, you will notice that the patient will be severely-totally deaf on the side of the positive head impulse test (there is ONE report of such a case where hearing was supposedly spared)so the short answer is yes, its an excellent first approximation.