Neuroprostheses in Transverse Lesions of the Cervical Cord

Abstract

In the peripheral nerve an action potential can be elicited, that is indistinguishable from any action potential evoked by physiological mechanisms (11). The response of the end-organ, the muscle contraction, is identical in most situations. By coordinated stimulation of peripheral nerves and muscles “natural” movements can be synthesized. This method of functional electrical stimulation (FES) developed in the last 20 years can therefore substitute for some central mechanisms in patients with central motor lesions who have intact peripheral nerves and muscles. Although today neuroprostheses are still in the first stages of clinical application, the method has the potential to be beneficial for many patients being serverely handicapped by central motor lesions. Recent developments in microelectronics, material research, neurophysiology and other related areas, have given new impetus to neuroprosthesis research and resulted in the development of small microprocessor-controlled multichannel-stimulators (5,6,14,18, 19). Clinical research and application has been focused on two main targets, the restoration of grasping functions in quadriplegic patients (11,13,14) and the restoration of posture and gait in paraplegic patients (1–4,6–10,16–18).