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 the treatment of choice for patients with chronic back and leg pain frequently associated with FBS 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 neuromodulation, 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 process.

A carefully performed psychological evaluation will have several benefits including, identifying those patients most likely to benefit from neuromodulation, better preparing the patient 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 hospitalised 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 centres 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