Spinal cord stimulation: principles of past, present and future practice: a review

Abstract

Electric energy have been in use for the treatment of various ailments, including pain, since the time of Pharaohs. The theoretical basis of electrotherapy of pain was provided by the Gate Control Theory of Melzak and Wall. In 1965, Shealey et al. first introduced electrical stimulation of spinal cord for treating pain. At present spinal cord stimulation (SCS) is a well established form of treatment for failed back surgery syndrome, complex regional pain syndrome and refractory pain due to ischemia. The indications for SCS is growing and the technology involved in this is rapidly advancing, however, high level of scientific evidence is still lacking to support this form of therapy due to difficulties in blinding and comparing with control groups. Future developments in SCS could include, combined SCS-drug delivery system, bio feedback and closed loop systems.

Spinal Stimulation for Pain: Future Applications

“…Since its inception in 1967 by Shealy et al [1][2][3], SCS evolved in both conceptual and practical dimensions. The systems became more complex, and the choice of individual components gave clinicians many options with different degrees of invasiveness, selectivity, longevity, and adjustability.…”

“…The number of clinical indications for SCS remained relatively stable over the years-the dominant categories remain chronic radiculopathy (such as in failed back surgery syndrome), complex regional pain syndromes (type 1 and 2), and pain due to ischemia (coronary or in extremities) [2][3][4][5]. Some indications have faded away (cancer pain, pain associated with spasticity, postherpetic neuralgia, brachial plexus avulsion, phantom pain after amputations) [3,6], while others seem to be growing (low back pain, headaches) [7,8].…”

“…Some indications have faded away (cancer pain, pain associated with spasticity, postherpetic neuralgia, brachial plexus avulsion, phantom pain after amputations) [3,6], while others seem to be growing (low back pain, headaches) [7,8]. Radiofrequency-coupled systems became replaced by implantable pulse generators, and simple electrode combinations became supplemented by complex multicontact configurations.…”

Spinal Stimulation for Movement Disorders

“…The technique consists of inserting an epidural lead containing multiple stimulating electrodes (4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16). The leads can be percutaneous or surgical paddle leads.…”

“…Implantation of the whole SCS system requires a surgical procedure under aseptic conditions. In patients suffering from chronic and intractable neuropathic pain, SCS results in pain relief, improvement in activities of daily living, and a reduction in analgesics dosage [2][3][4][5]. Neuroimaging studies using either functional magnetic resonance imaging techniques and positron emission tomography with H 2 15 O have suggested an activating effect of SCS within the thalamus contralateral to the pain, somatosensory, premotor, anterior cingulate cortex, and prefrontal areas [6,7].…”