Various studies in the animal model have shown recovery of stepping with spinal cord epidural stimulation following a spinal cord injury. Our group had shown that epidural stimulation of lumbosacral spinal cord, combined with activity based training, enabled four motor complete paraplegics to progressively regain full weight bearing standing and achieve voluntary movement of their lower extremities.
The objective of this study is to determine whether task-specific epidural stimulation in combination with intense step training can recover independent stepping on a treadmill with partial weight bearing in subjects with a motor complete injury.
Three individuals with a motor complete injury (2 AIS-B and 1 AIS-A) implanted with an epidural electrode array over the L1-S1 segments of the spinal cord participated in this study. Individuals received intense step training with step scES and stand training with stand-scES for 160 sessions. EMG, kinematics and ground reaction forces were recorded during stepping on a treadmill with body weight support.
All three individuals were able to independently generate a full step cycle (stance and swing) with optimized subject specific stimulation parameters for stepping following 20-60 training sessions. The maximum number of consecutive steps generated by the three subjects were 94, 319 and 381 steps. Intention to step with a specific leg (left or right) was needed for independent stepping of that same leg to occur. Although both left and right legs of a given subject could generate independent stepping cycles, neither of the subjects could step bilaterally, simultaneously. These results have important implications with respect to identifying strategies that are likely to be most efficacious in enabling improved motor function for stepping after motor complete paralysis. This study provides evidence that the combination of intense step training with task-specific Step-scES promotes significant plasticity in the spinal circuitry leading to improvements in stepping performance.
Authors: *C. A. ANGELI1,2, Y. GERASIMENKO4,5, V. EDGERTON4, S. J. HARKEMA3,1;
1Frazier Rehab Inst., Louisville, KY; 3Dept Neurol Surgery, 2Univ. of Louisville, Louisville, KY; 4Univ. of California Los Angeles, Los Angeles, CA; 5Pavloc Inst., St Petersburg, Russian Federation
Disclosures: C.A. Angeli: None. Y. Gerasimenko: None. V. Edgerton: None. S.J. Harkema: None.
NININ Grant R011EB007615
MS P30 GM103507
Christopher and Dana Reeve Foundation
Leona M and Harry B Helmsley Charitable Trust
Kentucky Spinal Cord Injury Research Center
University of Louisville Foundation
LINK: Society for Neuroscience