[The exploration on optimization of two alternatives between roll test and Dix-Hallpike test in benign paroxysmal positional vertigo].

Objective: To analyze the objective characteristics of roll test and Dix-Hallpike test in benign paroxysmal positional vertigo(BPPV)patients, discussing the premier solution of positional test. Methods: A total of 230 patients with BPPV, whereas 170 posterior semicircular canal canalithiasis (PSC-Can) BPPV and 60 horizontal semicircular canal canalithiasis (HSC-Can) BPPV were involved respectively. The induced nystagmus in roll test and Dix-Hallpike test was recorded by video nystagmuo graph (VNG), and the direction, intensity and time characteristics of nystagmus were compared in various BPPV.SPSS19.0 software was used for statistical analysis. Results: Vertically upward nystagmus was induced by hanging in 170 PSC-Can Dix-Hallpike test, and the nystagmus reversed and turned weaker when the subjects came to sit. The intensity of nystagmus at turning to lesion side by hanging and sitting were (30.3±14.1)°/s and (12.6±7.5)°/s respectively, the difference was statistically significant (t=20.153, P<0.05). However, no nystagmus was induced in PSC-Can roll test. Horizontal nystagmus in the same direction with turning was induced in 60 HSC-Can roll test. The intensity of nystagmus at turning to lesion side and normal side was (42.0±18.0)°/s and (20.3±8.7)°/s respectively, the difference was statistically significant (t=12.731, P<0.05). Furthermore, horizontal nystagmus in the same direction with turning was induced in 57 HSC-Can Dix-Hallpike. The coherence was 95% with the results of roll test. Conclusions: Dix-Hallpike test can not only be used to diagnose PSC-Can, but also induce nystagmus in HSC-Can effectively. Whereas the roll test only show significance in diagnosing HSC-Can. To avoid uncomfortable stimulation to patients as much as possible, we suggest to use Dix-Hallpike test at first, and to judge whether using roll test based on the result of the horizontal nystagmus.