ABSTRACT
Objective@#To observe the position of the electrode in the cochlea following cochlear implantation by cone beam computed tomography (CBCT).@*Methods@#Twenty-five children who received cochlear implantation and CBCT examinations in the Department of Otorhinolaryngology Head and Neck Surgery from the Second Hospital of Shandong University between January 2016 and December 2017 were selected. There were 15 males (17 ears) and 10 females (10 ears). The age ranged from 0.5 to 7.0 years old, with a median age of 1.6 years. 23 patients with unilateral implantation and two patients with bilateral implantation. The implants were all Med-El standard 12-electrode contact arrays. The CBCT was used to determine the position of the electrode in the cochlea, the distance between the electrode contacts and modiolus, and intracochlear insertion length of the electrode arrays. SPSS Statistics, version 22.0 was used for data processing and statistical analysis.@*Results@#CBCT images could clearly demonstrate the structure of round window, oval window, modiolus, osseous cochlear duct, osseous spiral lamina, and electrodes. The electrode arrays of all the children were fully implanted into the cochlea. 26 of the electrode arrays were located in the scala tympani and one of them was inserted into the scala vestibular. The mean intracochlear insertion length of the electrode arrays was 30.23 (95%CI, 30.04-30.71) mm. The distance between the electrode contacts and modiolus gradually increased at the 1-4th electrode contacts and reached the maximum at the 4th electrode contacts with an average of 1.10 mm (95%CI, 1.02 to 1.18 mm), and then gradually decreased from the 5th electrode contacts.@*Conclusions@#CBCT can clearly show cochlear fine structures and therefore accurately assess the electrode position following cochlear implantation.
ABSTRACT
<p><b>OBJECTIVE</b>To discuss the video head impulse tests (vHIT) application values in assessment of the vestibular nerves, function in sudden deafness patients with vertigo.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSIONS</b>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.</p>