HST and SVINT as Substitutes for Caloric Testing. Theoretical Basis and Practical Use

The study considers the hypothesis (supported by a compatible theory) that the vibratory test (SVIN) corresponds to unilateral weakness (UW) in caloric tests and that the head-shaking test (HST) is directly proportional to directional preponderance (DP). A group of 76 patients with vestibular deficits at various stages of compensation, confirmed by bithermal tests using the Fitzgerald-Hallpike technique and evaluated with Jongkees' formulas, was studied and compared with SVIN and HST results. The statistical study shows a marked correlation between SVIN and UW and between HST and DP. At the same time, the cross-correlations between SVIN and DP, and between HST and UW, are significantly weaker, confirming the hypothesis. It is concluded that, in cases where caloric testing is not considered necessary, these two bedside functional tests can give a precise idea of the results of caloric testing and that this interpretation can highlight the great clinical potential of SVIN and HST performed in combination.