Multiphysics coupling study on the effect of blood flow pulsation in patients with pulsatile tinnitus

This work aimed to investigate the effect of blood flow pulsation in patients with pulsatile tinnitus (PT). Nine blood flow patterns with different pulsations were designed on the basis of the blood flow data of a patient with PT (control group; cases with blood flow pulsation indexes that had decreased by 20%, 40%, 60%, and 80%; and cases with blood flow pulsation indexes that had increased by 20%, 40%, 60%, and 80%). The transient-state multiphysics coupling method was used to clarify the biomechanical and acoustic changes that had occurred under different blood flow pulsations. Results showed that blood flow impacted directly the vessel wall in the sigmoid sinus wall dehiscence (SSWD) area. The impact velocity of the blood flow slowed with the decrement in blood flow pulsation index but increased with the increase in blood flow pulsation index. With the reduction in blood flow pulsation index, the average pressure of the SSWD area decreased by 1.84, 3.93, 6.23, and 8.31 Pa; the average displacement of the vessel wall in the SSWD area decreased by 0.11, 0.23, 0.36, and 0.48 mm; and the average sound pressure level at the tympanum decreased by 2.2, 4.16, 7.14, and 12.97 dB. By contrast, with the increase in blood flow pulsation index, the average pressure increased by 2.46, 4.21, 6.28, and 8.56; the average displacement increased by 0.14, 0.2, 0.36, and 0.49 mm; and the average sound pressure level increased by 1.32, 2.87, 4.15, and 5.19 dB. Statistical analysis revealed that the pathological induction of PT had a strong quadratic correlation with the pulsation of blood flow. The degree of PT could be attenuated by reducing blood flow pulsation. Such an approach would aid clinical treatment. The conclusion obtained in this work would present a theoretical basis for the treatment of patients with PT. (C) 2021 Nalecz Institute of Biocybernetics and Biomedical Engineering of the Polish Academy of Sciences. Published by Elsevier B.V. All rights reserved.