Case Study Testing the Use of Implanted Microstimulators for Decreasing Spasticity and Improving Motion Following Spinal Cord Injury

Restoring mobility after spinal cord injury (SCI) is one of the most important goals of rehabilitation. Even for patients with partial lower limb motor function after SCI, many have limited mobility because of significant spasticity. Therapeutic electrical neuromuscular stimulation (TNS) has been used to improve muscle tone and strength and to enable walking and standing in patients with SCI. We propose to use the Radio Frequency Microstimulator (RFM) System, a new and novel implantable TNS system developed by the Alfred E. Mann Foundation, to improve muscle strength and reduce spasticity in a patient with incomplete SCI. The RFM System has several advantages over current TNS systems. The RFM implant devices are small enough (diameter 2.4 mm, length 16.7 mm) to be inserted using an incision approximately 5 mm long and have no lead wires passing through the skin since the microstimulator contains both the anode and cathode. Implanted RFM devices can be placed near multiple motor points and/or nerves and are controlled individually using radio frequency technology. Up to six (6) RFM devices will be inserted, two to three in each lower limb to provide stimulation to a patient's bilateral knee extensors (femoral nerve stimulation) and ankle dorsiflexors (peroneal nerve stimulation) to assess the effects on muscle strength, limb spasticity and patient mobility.