Endovascular neuromodulation: Feasibility of endovascular stimulation near the cerebellum.

OBJECTIVE: Electrical stimulation and neural recording underpin neural prostheses for restoring function and treating neurological disorders, but clinical adoption is limited by the invasiveness of implantation. The Endovascular Neural Interface offers an alternative by accessing intracranial targets through the cerebral vasculature. This work presents the first strength-duration characterization of cortical evoked potentials, elicited by endovascular stimulation, adjacent to the cerebellum. APPROACH: A polymer-based stent-electrode array was deployed into the left transverse sinus of an ovine model. Biphasic current pulses targeting the cerebellum were delivered via the stent electrodes. Cortical responses were recorded using a subdural electrocorticography (ECoG) grid. MAIN RESULTS: Endovascular stimulation consistently evoked time-locked cortical potentials with early and late components at approximately 40 ms and 100 ms post-stimulation. Electrode functionality and stability were confirmed through impedance monitoring throughout the experiments. Strength-duration analysis revealed rheobase and chronaxie values, providing a quantitative basis for parameter selection and comparison with established intracranial stimulation modalities. SIGNIFICANCE: These results demonstrate that endovascular electrodes may access non-superficial brain structures and evoke reproducible cortical responses without open neurosurgery. This work helps establish a foundational framework for endovascular neuromodulation and supports further investigation of its potential forfuture closed-loop and network-level neuromodulation research.