INDICATIONS AND PATIENT SELECTION FOR NEUROSTIMULATION

	Many patients with chronic pain will respond to a combination of physical therapy, oral medication and other conservative therapies. Some will need surgical intervention to address the mechanical condition causing the pain, while others may require advanced interventions. Neurostimulation is an effective alternative to destructive procedures or more costly spinal surgeries in selected patients.
	General selection criteria for neurostimulation For neurostimulation to be considered as a treatment option, patients should meet the following general selection criteria: ● There is an objective basis for the patient’s pain complaint ● The patient is psychologically competent and has no psychological contraindications ● Further corrective surgeries are likely to produce complications or poor outcomes ● More-conservative therapies have failed to relieve pain or have caused intolerable adverse events ● No contraindications to surgery exist (e.g. sepsis, coagulopathy) ● No untreated chemical dependency exists ● Neurostimulation and IDD are not contraindicated Neurostimulation is considered as the treatment of choice for patients with chronic back and leg pain frequently associated with FBSS whose pain manifests despite anatomically successful surgery, and for the treatment of patients with CRPS who are unsatisfactorily controlled on existing therapies. Neurostimulation has also proved effective in difficult-to-treat populations where other therapies have failed.
	Patient selection for neurostimulation Before a patient becomes a candidate for neurostimulation, the patient should undergo a thorough evaluation, which should include both physical and psychological elements. In addition, all patients should undergo a trial procedure.
	Physical evaluation A comprehensive history and physical examination of the patient should be completed to ensure that there is an objective basis for the pain. A complete pain history includes a general medical history with emphasis on the chronology and symptomatology of the pain. These data should include information about the onset, quality, intensity, distribution, duration, course and affective components of the pain, and details about exacerbating and relieving factors. The physical examination should also include an appropriate neurological and musculoskeletal evaluation. The effects of pain, as well as the causes of pain, should be evaluated and recorded. In addition, the physician should determine the pain type, pain pattern, and sources of pain. Determination of such pain characteristics allows the physician to select the appropriate therapy.
	Psychological evaluation Most physicians agree that before considering a neuromodulation procedure, the patient should be assessed by a psychiatrist or a psychologist to rule out any psychological issues that may affect the therapeutic outcome. This psychological evaluation should take place in the early phase of the patient selection procedure. A carefully performed psychological evaluation will have several benefits including, identifying those patients most likely to benefit from neuromodulation procedures, better preparing the patient for the neuromodulation procedure, and setting realistic expectations. It can also aid in preventing unsuitable candidates from undergoing an invasive and costly procedure and redirecting rejected candidates to more appropriate treatment programs.
	Neurostimulation trial procedure Conducting a test stimulation before ‘permanent implantation’ allows patients and the pain management team to test neurostimulation for both efficacy and paraesthesia perception, which sometimes cannot be tolerated despite good pain relief. There is no consensus on either the technical approach or the length of the SCS trial. In addition, whether the trial should be carried out in hospitalized patients or on an outpatient basis is a matter of personal opinion, since there are no data to support any specific recommendations. The criteria for a successful trial include at least a 50% reduction in pain intensity and in those centers able to measure it, a decrease in analgesic intake and a significant functional improvement. Patients that show substantial improvements in these parameters can be considered for a permanent implantation.
	Indications for neurostimulation There is a large pool of evidence supporting the beneficial effects of neurostimulation. In general, neurostimulation is most effective for neuropathic pain, typically when the pain is of non-malignant origin (i.e. pain from a source other than cancer). Neurostimulation is CE marked for: ● Chronic, intractable pain of the trunk or limbs ● Neuropathic pain ● Stable pain patterns Neurostimulation may also be used when other therapy methods are contraindicated. For example, neurostimulation may be indicated for patients for whom spinal surgery is contraindicated and for patients who may not fully profit from reoperation.