Investigation of Vestibular Evoked Myogenic Potential (VEMP) results at different dynamic equilibrium positions

''Examination of Vestibular Evoked Myogenic Potentials (VEMP) Results in Different Dynamic Balance Positions'', Trakya University Institute of Health Sciences, Department of Audiology, Master's Thesis, Edirne, 2024 Introduction and Aim: This study aimed to investigate the possible changes in a person's balance system in different postures and positions with the Cervical Vestibular Evoked Myogenic Potentials (c-VEMP) test. Materials and Methods: After obtaining ethics committee approval and an informed consent form, our study was conducted at Trakya University Health Application and Research Center on 45 healthy and volunteer individuals, with repeat tests in different postures and positions. All volunteer participants first underwent otoscopic examination and hearing and balance examination, and then audiological evaluations for the presence of normal hearing. For individuals with normal hearing, the c-VEMP test was performed in 3 different situations: standing on a flat surface with eyes open, standing on a flat surface with eyes closed, and standing on a Foam Pad with eyes open. P1-N1 latencies and amplitudes were evaluated in c-VEMP responses. The data obtained was analyzed statistically. Results: In our study, when we evaluated the c-VEMP responses while standing on a flat surface with eyes open and closed, a statistically significant prolongation was observed in the left P1-N1 latencies in the closed position compared to the open position, while a decrease was observed in the amplitudes of both ears (Sağ P1-N1 Amp-p=0,009; Sol P1-N1 Amp-p=0,006; Sol P1; N1-p=0,001). When we compared the situation with eyes open while standing on the flat ground with the situation with eyes open while standing on the Foam Pad, no statistically significant difference was observed in the amplitudes and latencies of the waves of both ears (p>0,05). Lastly, when we evaluated the results of the eyes open position standing on the Foam Pad and the eyes closed position standing on the flat ground, a statistically significant prolongation of the right N1, and left P1-N1 latencies and a decrease in the wave amplitudes of both ears were observed in the closed position compared to the open position (Sağ P1-N1 Amp-p=0,012; Sol P1-N1 Amp-p=0,013, Sağ N1-p=0,029; Sol P1-p=0,046; N1-p=0,001). Conclusion: The disappearance or inadequacy of any of the systems responsible for controlling the balance is compensated by other systems; however, the balance is affected by this situation. As a result of our study, in addition to the vestibular system, we think that the information coming from the visual system has a greater role in maintaining balance than the information coming from the proprioceptive system.