The skull vibration induced nystagmus test in cochlear-implanted patients: a prospective study in 51 patients

Overview & Synopsis

Objectives: To evaluate the benefit of the skull vibration-induced nystagmus test to diagnose vestibular disorders in cochlear implantation. Methods: Prospective monocentric study in the french cochlear implant center of the Alps, between January 2014 and January 2016 in 51 patients who received a cochlear implant. The vestibular function was studied with SVINT (skull vibration-induced nystagmus test) and compared with vestibular evoked myogenic potential (VEMP) and caloric testing (CT). Patients with inner ear malformations and preoperative dizziness were excluded from the study. The surgery consisted of the insertion of the electrodes through a round window niche. Results: Before surgery, SVINT was positive in 11 (22%) patients and remained so after surgery. Three additional patients had positive SVINT after surgery making a total of 14 (27%) patients. Concerning CT, preoperatively, 36 (71%) cases had normal test and after surgery, 24 (47%) patients had normal CT on both sides. For SVINT, sensitivity was 67% and specificity was 98% before surgery. After surgery, sensitivity was 52% and specificity was 100%. Conclusion: The SVINT is a rapid, non-invasive test and is complementary to other tests in detecting vestibular disorders after cochlear implantation.