Multi-site closed-loop stimulation strategy for seizure control with a generalized neurostimulator

The requirements of exploring multi-site responsive stimulation for epilepsy treatment have driven the development of neurostimulator with more recording channels, more stimulation channels, and more powerful on-board calculation. In this paper, a multi-channel closed-loop stimulation system based on FPGA platform, which implements 32-channel 30kS/s recording and 4-channel arbitrary waveform (up to 1mA, ±15V voltage compliance) constant-current stimulation, was adopted for seizure control on kainic-acid injected rodents. Seizure can be detected autonomously within the FPGA and trigger flexible stimulation patterns using a custom application on PC. Four triple-electrodes were implanted into rat's motor cortex, CA1, CA3 and STN for signal recording and electrical stimulation. The responsive stimulations were delivered once seizure patterns were detected on any channel. In-vivo results showed various epileptiform electrographic patterns at different site with different onset time. The multi-site stimulation in different brain area rather than single target stimulation are promisingly a better strategy for seizure control.