VIN results
The MVSP of nystagmus evoked in each stimulation were significantly decreased in the control group when compared to those in the VS patients, except for ipsilateral SCM stimulation at 100 Hz, which was not statistically significant. Higher MVSP values were registered with either ipsilateral or contralateral mastoid stimulation than with other stimulation modes (p<0.05).
We did not observe any significant differences between the ipsilateral and contralateral stimulation parameters in either the mastoid or SCM between the case and control groups.
The areas under the curve and the sensitivity and specificity for each cut points, are shown in Table 2.
There were no significant differences in sensitivity among the different sites or stimulation sides (p > 0.05). The sensitivity and specificity were highest (81, 8% and 73, 9%, respectively) when calculated based on the presence of a VIN with any mastoid stimulation (Figure 2).
Vertical VIN was detected in just 5 of 33 (15.5%) patients tested. No subjects from the control group developed vertical VIN. Vertical VIN sensitivity and specificity were not calculated due to small numbers of patients.