Three cases of patients with acute onset vertigo are presented here. The presenting symptoms are described for each case along with the results of vestibular and audiologic examination. This paper focuses on the results of vHIT in the plane of the horizontal and vertical canals, cVEMPs and oVEMPs. The results of the tests make a good case for exploiting the ability of these tests to give information about the function of the whole vestibular system. These three patients all had abnormal VEMPs (cervical, ocular or both) but normal vHIT responses which the authors’ state shows selective otolith dysfunction. Call me old fashioned, which I’m sure many of you will (including the eminent authors of this paper), but I was left wondering what the caloric results looked like. None of the patients cited here had calorics. I completely accept that there are severe limitations to caloric testing, which are outlined in this paper, but in my own practice I see patients reasonably often who have normal vHIT results but an asymmetry on calorics that is consistent with their symptom profile or other assessment such as VEMPs. I am aware that factors other than horizontal canal function may influence a caloric result but, taking into account any of these as far as they can be known in an individual case, I would still consider a caloric asymmetry to be evidence of abnormal horizontal canal function, albeit at low frequency, especially when it is consistent with other findings. I would be more convinced of selective otolith dysfunction in these cases had caloric testing (where appropriate) also been normal in addition to vHIT. I support the argument for using the newer tests to explore vestibular function beyond the horizontal canal and these cases provide a good example of how this can yield additional information. I’m just not quite sure I am ready to abandon the older tests yet. It will also be interesting to see how this extra information regarding dysfunction supports management decisions and prognosis.
Selective otolith dysfunctions objectively verified
Reviewed by Fiona Barker
Selective otolith dysfunctions objectively verified.
CONTRIBUTOR
Fiona Barker
Department of Clinical Medicine and Ageing, University of Surrey, UK.
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