Presented at the 2012 AAPM Annual Meeting « Back

Physical Activity and Patient Programmer Usage in Spinal Cord Stimulation Patients

Cristy M. Schade, MD PhD PE, cmschade@cpctx.com¹, David M. Schultz, MD², Nancy Tamayo, DC¹, Sudha Iyer, PhD³, Eric Panken, MS³, (1) Center for Pain Control, Garland, Texas, (2) MAPS Applied Research Center, Edina, Minnesota, (3) Medtronic, Inc., Minneapolis, Minnesota

Introduction: As the spinal cord moves in the subarachnoid space during posture changes, the distance between the spinal cord and stimulating electrodes changes, thus changing the patient’s perception of stimulation. The number and types of position changes that patients make and patient programmer usage have not been extensively studied. Materials and Methods: Twenty patients (ages 43–66 years; six men and 14 women) previously implanted with Restore™ or Restore Advanced™ neurostimulators (Medtronic, Inc., Minneapolis, MN) for ≥ 3 months for chronic low back and/or leg pain were enrolled in the study. Eighteen patients completed 3 days of outpatient monitoring wearing an external accelerometer to record physical activity and position changes. Patients annotated and time-stamped physical activities in an electronic diary. A modified patient programmer recorded all the therapy adjustments. Results are presented as median [min, max]. Results: Patients changed position or activity 72.9 [22.1, 192] times per 24 hours; spent 11.1 [4.7, 17.4] hours lying down; 9.8 [4.9, 17.6] hours upright; and 2.3 [0.2, 6.6] hours mobile per day. The patient programmer was used 5.6 [3.3, 19.7] times per day to make 61 [12.8, 289.2] amplitude; 0 [0, 31] rate; 0 [0, 66] pulse width; and 0 [0, 3.3] group adjustments per day. Conclusions: Position changes and stimulation amplitude adjustments occurred frequently during a 24-hour period. The ability of an implantable neurostimulator to automate stimulation intensity adjustments during position and activity changes may reduce patient burden, provide more consistent paresthesia, increase comfort, and yield greater patient satisfaction and better therapeutic outcomes.

Funding: Medtronic Neurological