Incorporating vascular structure into electric volume conduction models of the cochlea

Volume conduction models (VCMs) of the cochlea have been used to investigate its response to electrical stimulation. However, existing models have not accounted for the presence of blood vessels, despite the relatively low resistivity of blood and the pervasiveness of the vascular network. The finite element model developed in this paper represents a first step towards a vascularized VCM of the cochlea. The results show that the inclusion of blood vessels makes localized differences to the current distribution, and that these differences are amplified when fibrous scar tissue and anisotropic nerve tissue are also modeled. Current densities and electric fields in the spiral ganglion are also affected, though the differences are not expected to have a major impact on activation thresholds. As predicted, larger vessels have a greater influence on the end result and should be considered in future modeling efforts.