Observational, prospective, single-center to assess neuronal activation accuracy and stimulation sensation in patients with closed-loop spinal cord stimulation therapy.

The study follow patients with chronic pain who received an EvokeTM spinal cord stimulator. The main aim of this study is to evaluate what influence different settings on nerve activation have and how this affects patients' sensation.

Inclusion Criteria:

• Subject is deemed a suitable candidate for SCS trial and permanent implant and has been routinely scheduled to undergo an SCS trial phase with the Evoke SCS System.
• Subject has a minimum of pain intensity of 5/10 on the numeric rating scale (NRS) at baseline
• Subject is ≥ 18 years old.
• Subject is not pregnant or nursing.
• Subject is willing and capable of giving informed consent.

Exclusion Criteria:

• Subject currently has an active implantable device including pacemakers, spinal cord stimulator or intrathecal drug delivery system.
• Subject is incapable of understanding or responding to the study questionnaires.
• Subject is incapable of understanding or operating the patient programmer handset.

Subjects suffering from chronic pain and are eligible for SCS trial and permanent implant.