Comparison of the Efficacy of Video Head Impulse and Bi-Thermal Caloric Tests in Vertigo

Abstract

Objective: To compare video head impulse test (vHIT) and caloric test efficacy in decompensated and compensated vertigo patients and to further investigate whether vHIT alone can be used as a diagnostic tool in vertigo. Methods: This study included 25 patients diagnosed with vertigo and without any previous history of vertigo or hearing loss before their admission to our clinic. The control group consisted of 16 healthy adult volunteers. Patients were classified into 2 groups, compensated and decompensated. Video head impulse test and caloric tests were performed and the results were compared between the groups. Results: The difference of caloric test values between control-compensated groups and compensated-decompensated groups was statistically significant (P < .001, Pearson chi(2)). However, there was no statistically significant difference between the compensated and control groups according to vHIT gain asymmetry values (P = .087). In the very early stages of the disease with spontaneous nystagmus, the diagnostic significance of vHIT was similar to that of the caloric test. When both sides were compared, vHIT gain asymmetry values were close to the caloric test asymmetry values. In the compensated stage, caloric test was superior to vHIT in differentiating compensated vestibular pathologies. When vHIT sensitivity was evaluated according to the bi-thermal caloric test results, the sensitivity of the vHIT gain asymmetry value was 85.71\% and 23.08\% for decompensated and compensated patients respectively. Conclusion: In the early decompensated stages of the disease with spontaneous nystagmus, vHIT shows similar diagnostic accuracy to that of the caloric test. Since patients can tolerate vHIT more easily, our results suggest that vHIT can be considered as a primary evaluation method in the early (decompensated) period of the disease and should be preferred over the caloric test during the acute phase. Caloric test is more reliable at the compensated stage. Video head impulse test is inadequate in evaluating the compensated vestibular hypofunctional states after compensation has been restored.