Epidural and transcutaneous spinal electrical stimulation for restoration of movement after incomplete and complete spinal cord injury.
Mayr W, Krenn M, Dimitrijevic MR
PURPOSE OF REVIEW:
The Purpose of this review is to outline and explain the therapeutic use of electrical spinal cord stimulation (SCS) for modification of spinal motor output. Central functional stimulation provides afferent input to posterior root neurons and is applied to improve volitional movements, posture and their endurance, control spasticity, and improve bladder function or perfusion in the lower limbs. Clinical accomplishments strongly depend on each individual's physiological state and specific methodical adaptation to that physiological state.
Effectiveness of this neuromodulory technique for changing motor control after spinal cord injury (SCI) continues to be explored along with the underlying mechanisms of its effect in people with complete and incomplete spinal cord injuries. There are extensive studies of tonic and rhythmical activity elicited from the lumbar cord as well as data demonstrating augmentation of residual volitional activity. Recent studies have focused on verifying if and how SCS can modify features of neurocontrol in ambulatory spinal cord patients.
In this review, we emphasize recent publications of research revealing that SCS can substitute for the reduced brain drive for control of excitability in people with SCI. Artificially replacing diminished or lost brain control over the spinal cord has limitations. A fundamental requirement for successful SCS application is analysis of each individual's residual postinjury neural function. This will allow a better understanding of the physiological interactions between SCS and spinal cord motor control below injury and provide criteria for its application. Finally, the publication of both successful and failed applications of SCS will be crucial for gaining future progress.