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1、<p><p>&lt;p&gt;Effect of epidural stimulation of the lumbosacral spinal cord on voluntary movement, standing, and assisted stepping after motor complete paraplegia: a case study Presented by: Monzurul Alam 18th July 2011 Authors Susan Harkema, Ph.D. Professor, Dep
2、artment of Neurological Surgery Rehabilitation Research Director, Kentucky Spinal Cord Injury Research Center Owsley B. Frazier Chair in Neurological Rehabilitation University of Louisville, KY, USA V. Reggie Edgerton, Ph.D. Professor, Department of Neurobilogy Vice Chair, Integrative Biology and Ph
3、ysiology University of California, Los Angeles, CA, USA. Story ? A 23-year-old man who had paraplegia from a C7T1 subluxation as a result of a motor vehicle accident in July 2006, ? He was presented with complete loss of clinically detectable voluntary motor function and partial preservation of sens
4、ation below the T1 cord segment. ? After 170 locomotor training sessions over 26 months, a 16- electrode array was surgically placed on the dura (L1S1 cord segments) in December 2009, to allow for chronic electrical stimulation. ? Spinal cord stimulation was done during sessions that lasted up to 25
5、0 min. 29 experiments and several stimulation combinations and parameters were carried out with the aim of the patient achieving standing and stepping. Findings ? Epidural stimulation enabled the man to achieve full weight- bearing standing with assistance provided only for balance for 425 min. ? Th
6、e patient achieved this standing during stimulation using parameters identified as specific for standing while providing bilateral load-bearing proprioceptive input. ? We also noted locomotor-like patterns when stimulation parameters were optimised for stepping. Additionally, 7 months after implanta
7、tion, the patient recovered supraspinal control of some leg movements, but only during epidural stimulation. Video evidence Hypothesis ? Repeated stimulation of the spinal cord and training increased the ability to control movement in animal models of spinal cord injury. ? Tonic epidural spinal cord
8、 stimulation can modulate spinal circuitry in human beings into a physiological state that enables sensory input from standing and stepping movements to serve as a source of neural control to undertake these tasks. Mean EMG amplitude during standing and stepping with bodyweight support before implan
9、t EMG=electromyography. RF=rectus femoris. VL=vastus lateralis. MH=medial hamstrings. TA=tibialis anterior. Sol=soleus. MG=medial gastrocnemius. Result: No Improvement even after 170 sessions! Leg EMG activity with epidural stimulation of the lumbosacral segments during standing ?(A) EMG activity in
10、creases in amplitude and becomes more constant bilaterally in most muscles as stimulation is increased in strength from 1 to 8 V (15 Hz) with a constant level of BWS (585/900 N 65%). ?(B) Reduction of BWS from 45% to 5% (405/900 N to 45/900 N) and with constant stimulation (8 V; 15 Hz) changed the E
11、MG amplitudes and oscillatory patterns differently among muscles. Video support: 1 figure 6; webvideos 4 and 5). ? Voluntary movement was observed in both legs, although the stimulation parameters were different. 2) Axonal regeneration or sprouting might have been induced via activity-dependent mech
12、anisms over a period of 7 months. From a neurobiological and clinical perspective, that this supraspinal control was manifested only in the presence of continuous tonic epidural stimulation is important. Seemingly, conscious control was regained by increasing the level of spinal interneuronal excitability with stimulation to a crucial, but subthreshold level, allowing control via descending pathways. &lt;/p&gt;</p></p>
