The current technology for circular electrode contacts on implanted leads for deep brain stimulation (DBS) has a major limitation: the electronic current flow is also a annular outflow from the cathode ring to an adjacent anode ring on the same lead. Although this arrangement works when the electrode contact is centered in the target site, e.g., the subthalamic nucleus (STN), it doesn’t work as well if the contact misses the small brain target. Current flow partially arrives at the target and the rest flows elsewhere in the brain, lowering efficiency and causing unwanted side effects.
To address this issue, the typical method is to place multiple contacts on the lead (typically four contacts) best placed superiorly or inferiorly for clinical efficacy. To reduce symptomatology, however, anterior-posterior or medial-lateral "misses" may require lead re-implantation.
UCF researchers have invented a novel approach for patients with multiple or bilateral implants where the electrode contacts are placed laterally to the target that electronically draw current in the direction of the target area. Unlike comparable implants, the electrical field can be shaped over space and time to reach more of the targeted area through the selection of various combinations of active contacts.
At the time of stimulation, the anode ring on the stimulating lead is turned off while the adjacent cathode ring is turned on, simultaneously turning the anode ring on another lead (such as a bilateral lead), which thereby draws the current density across the nearby target. The cathode lead directs the electrical field to the target and the placement and number of anode contacts activated determines the electric field path and rate of dissipation based on vertical and horizontal distance and timing.
This invention also provides correction parameters for implanted electrodes by applying a cathode pulse to a bilateral implanted electrode while providing a synchronized anode on the opposite electrode. The correction parameter can be applied to anode and cathode contacts on a single implanted lead. Each lead can have independently controllable anode and cathode contacts.
- Improved symptom control
- No need for additional surgeries for re-implantation
- Independently controllable anode and cathode contacts
- Deep brain stimulation (DBS)