[Evaluation of the injured range of vestibular superior and inferior nerves in sudden deafness patients with vertigo using video head impulse test].

OBJECTIVE: To discuss the video head impulse tests (vHIT) application values in assessment of the vestibular nerves, function in sudden deafness patients with vertigo.

METHODS: There were 60 cases (120 ears) of healthy volunteers as control group, and 182 cases (182 ears) of sudden deafness with vertigo patients as study group. The study group received vHIT and caloric test, and the control group received vHIT. Functions of vestibular superior and inferior nerves were analyzed by the gains of vHIT and the nystagmus, s unilateral weakness of caloric test, with SPSS17.0 software.

RESULTS: The values of vHIT-G of the six semicircular canals in the control group were normal distribution and no statistical significance among them (F = 0.005, P = 1.000). The vHIT-G averages of both sides of anterior, horizontal and posterior semicircular canals were (15.20 ± 11.00) %, (15.30 ± 13.30) %, and (15.15 ± 14.72) % respectively. In the study group, the vHIT-G of the affected side were (21.73 ± 14.84) %, (21.20 ± 28.24) %, and (19.22 ± 23.50) %, with normal distribution, and in which statistical significance was detected comparing with those in the control group (P < 0.05). The positive rates were 26.9% (49/182) in vHIT, 70.3% (128/182) in caloric test. Significant difference (P < 0.05) was observed between vHIT and caloric test examined by chi-square test. According to the results of vHIT, there were 15 cases (8.2%) damaged vestibular superior and inferior nerves areas, 19 cases (10.4%) damaged the superior vestibular nerve area, and 15 cases (8.2%) damaged the inferior vestibular nerve area. In combination with caloric test results, it was shown that there were 29 cases (15.9%) damaged vestibular superior and inferior nerves areas, 101 cases (55.5%) damaged the superior vestibular nerve area, and 1 case (0.5%) damaged the inferior vestibular nerve area.

CONCLUSIONS: vHIT can assess the function of six semicircular canals and illustrate high frequency of vestibular nerves. Caloric test combined with vHIT have more advantages to comprehensive assess vestibular damage of sudden deafness patients with vertigo.