Use of Implanted Microstimulators for Decreasing Spasticity and Improving Motion Following Spinal Cord Injury

Use of Implanted Microstimulators for Decreasing Spasticity and Improving Motion Following Spinal Cord Injury

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

The primary aims of this study are to determine the safety of the RFM System (Alfred Mann Foundation, Santa Clarita, CA) in a patient with incomplete SCI and the effect of the RFM system on lower limb strength and spasticity. The secondary aim is to analyze any improvement in the participant's mobility.

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.

Therapeutic Electric Stimulation, Functional Electric Stimulation, Implantable Stimulator, Muscle Strength, Muscle Spasticity

Implantable peripheral muscle microstimulator, delivering controlled pulsatile stimulation to femoral nerves for knee extension and peroneal nerves for dorsiflexion.

Inclusion Criteria: an incomplete C6 ASIA C (Central Cord) spinal cord injury lower motor function impaired and suffers from significant spasticity (Ashworth scale 4) able to ambulate approximately 10-20 feet with a rolling walker and minimal assistance has sufficient endurance to complete at least two 20-minute therapy sessions per day cognitive abilities are intact Exclusion Criteria: psychiatric diagnosis medical contraindications history of bleeding disorders allergy to anesthesia acute or progressive disease active implantable device