A possible objective test to detect benign paroxysmal positional vertigo. The role of the caloric and video-head impulse tests in the diagnosis

Background

Benign paroxysmal positional vertigo (BPPV) is characterized by vertigo lasting from seconds to minutes, induced by head movements.

Objectives

Our study aimed to investigate the clinical significance of the caloric vestibular and video head-impulse tests (vHIT) diagnosing the disorder.

Methods

68 patients suffering from posterior canal BPPV (25 male, 43 females, mean age $\pm$ SD, 54.5 $\pm$ 13.2 years) and 56 patients with a normal functioning vestibular system as control were investigated. Bithermal caloric test and vHIT was performed during the same medical check-up. Canal paresis (CP%), gain (GA) and asymmetry (GA%) parameters were calculated.

Results

The Dix-Hallpike manoeuvre was only positive in 4% of this population. The CP% parameter was only pathologic in two patients, and there was no significant difference between control and BPPV patients (p = 0.76). The GA value was never under 0.8 in this population, but GA% was abnormal in 63.2%. A significant difference comparing the GA% values to the control group was seen (p = 0.034). There was no correlation detected between the CP% and GA% values in BPPV. Regarding the GA% value, 61% sensitivity and 76% specificity was seen.

Conclusion

The Dix-Hallpike manoeuvre was not often positive in the non-acute phase of BPPV; therefore, objective testing is essential. The caloric test does not have clinical significance in BPPV, but vHIT can be helpful based on the GA% parameter.