Comparison of cervical vestibular myogenic potentials before and after epley maneuver in posterior canal BPPV patients

Objective: Isolated posterior canal benign positional vertigo is the most common type of BPPV. The most valuable diagnostic tool in diagnosing the disease is positional maneuvers. However, positional maneuvers are subjective and affected by central suppressant drugs. In this thesis, it is aimed to reveal the change by comparing cervical vestibular myogenic potential (cVEMP) recordings, which is a more objective test in the evaluation of the disease, before and after treatment. Materials and Methods: Our study was conducted in the audiology department of Abant İzzet Baysal Training and Research Hospital Ear Nose and Throat Clinic. "Neurosoft, Neuro-Audio, Ivanova, Russia" device was used for sVEMP recordings. First of all, the VEMP device was calibrated by authorized technical personnel in accordance with the standards. cVEMP recordings (clik stimulus) (0.1 ms, 9.1 Hz) were obtained at 95 dB HL intensity and 100 averages. The active electrode was placed in the middle 1/3 of the SCM, while the reference electrode was placed in the supra-sternal notch region. The ground electrode is placed in the middle part of the forehead. The impedance of the recording electrodes was kept below 5 KOhm. During the test, clik and tone-burst stimuli were given to both ears separately at 95 dB, and they were examined and recorded separately before the treatment, 1 hour after the treatment and 1 week later. P1, N1 latencies and amplitude data of the healthy and patient groups were compared statistically. Results: In BPPV patients, when tone-burn stimulation was given to the patient's ears before treatment, P1 latency was found to be 17.93± 3.01 msec, N1 latency was 23.20± 2.96 msec, and P1-N1 amplitude value was 84.50± 32.22. In the same group, at the first hour after treatment, P1 latency was 15.96 ± 2.65 msec, N1 latency was 21.70 ± 2.54 msec, and P1-N1 amplitude value was 87.72 ± 33.73. When recording with tone-burst stimulus, a significant change was detected in P1 and N1 values when compared before and after treatment, but no significant change was observed in P1-N1 amplitude values.When the same recording was made with a clik stimulus, the P1 latency of the patient ears was measured as 14.80 ± 3.84 msec, the N1 latency was 19.06 ± 3.77 msec, and the P1-N1 amplitude value was 78.43 ± 27.84 before the treatment. After treatment, P1 latency in the patient ears was measured as 14.70 ± 3.58 msec, N1 latency as 19.90 ± 3.92, and P1-N1 amplitude value as 79.05 ± 33.97. In the recording made with the click stimulus, no significant change was detected in P1, N1 and P1-N1 amplitude values compared to before treatment. Conclusion: We think that the cVEMP test can be used as a low-cost, easy-to-use, practical and objective test in BPPV harvests. We also think that tone-burst stimulation may give more accurate results than clik stimulation in posterior canal BPPV patients.