Comparison of Dorsal Column Stimulation to Dorsal Root Ganglion Stimulation for Complex Regional Pain Syndrome

Complex Regional Pain Syndrome (CRPS) is a constellation of pain symptoms which are associated with impairment in mood, social and physical function. Spinal Cord Stimulation (SCS), a technique of placing electrodes into the epidural space is a validated treatment for Complex Regional Pain Syndrome . Treatment of CRPS with SCS, in combination with physical therapy, reduced pain to a greater degree than physical therapy alone. 40%-50% of CRPS patients achieve \>50% pain relief with SCS using dorsal column stimulation . Dorsal Root Ganglion (DRG) SCS has also recently demonstrated clinical efficacy in patients with CRPS and peripheral causalgia . The hypothesis is that DRG stimulation is non-inferior to dorsal column SCS in patients with CRPS who have failed to respond to a course of analgesics and physical therapy. The aim to assess functional, quality of life, patient satisfaction and medication requirements in subjects treated with neuromodulation for CRPS and contrast outcomes amongst subjects treated with DRG SCS and dorsal column SCS.

The purpose of this study is to compare outcomes between dorsal column spinal cord stimulation and dorsal root ganglion spinal cord stimulation in patients with Complex Regional Pain Syndrome at an infraumbilical location who have failed a course of conservative management including analgesic pharmacotherapy and physical therapy.

This is a prospective randomized post-marketing clinical study. Patients will be randomized in a 1:1 ratio to Dorsal Column or Dorsal Root Ganglion Spinal Cord Stimulation if they have failed a course of conservative management including analgesics and physical therapy. All patients are expected to undergo clinical, neurological, and imaging assessments, if appropriate, at selected follow-up visits.

The study will be conducted a single center with a target maximum of 62 patients (31 randomized to each group).

Enrollment of subjects in this study is anticipated to take 24 months. Clinical follow-up evaluations will be conducted at 10 days, 1, 3 and 6 months post-implant. The total study duration is expected to be at least 30 months.

All patients presenting to the Investigators with Budapest criteria, research subset , for the diagnosis of Complex Regional Pain Syndrome at an infraumbilical location who have not had an adequate response to a course of conservative management including analgesics and physical therapy will be screened for eligibility. A Screening/Enrollment Log will be utilized in order to maintain a cumulative tracking of all screened patients.

Patients must meet all inclusion/exclusion criteria for enrollment in the clinical study. Reasons for screening failure(s) will be documented.

Eligibility Criteria:
Inclusion Criteria:

* • Patient is greater than18 years of age

  * An infraumbilical location of the index pain
  * Symptoms have been present for greater than 6 months
  * Continuing pain which is disproportionate to any inciting event
  * Report hyperesthesia and/or allodynia
  * Report vasomotor changes including temperature asymmetry and/or skin color changes and/or skin color asymmetry
  * Report edema and/or sweating changes and/or sweating asymmetry
  * Report decreased range of motion and/or motor dysfunction (weakness, tremor, dystonia) and/or trophic changes (hair, nail, skin)
  * Display at least one sign in two or more of the following categories:

    * Sensory: Evidence of hyperalgesia (to pinprick) and/or allodynia (to light touch and/or temperature sensation and/or deep somatic pressure and/or joint movement)
    * Vasomotor: Evidence of temperature asymmetry (\>1°C) and/or skin color changes and/or asymmetry
    * Sudomotor/Edema: Evidence of edema and/or sweating changes and/or sweating asymmetry
    * Motor/Trophic: Evidence of decreased range of motion and/or motor dysfunction (weakness, tremor, dystonia) and/or trophic changes (hair, nail, skin)
  * Patient failed to have resolution of symptoms despite at least 4 weeks of conservative management including analgesic pharmacotherapy and physical therapy
  * Patient has index site pain \> spine pain
  * The subject is physically and mentally able to participate in the study
  * Patient is willing and able to provide informed consent
  * Patient is willing and able to comply with the study protocol

Exclusion Criteria:

* Previous surgery to the spine which could compromise placement of the study device
* Anatomical spinal abnormality including severe central canal stenosis or bony foraminal impingement which could preclude device placement
* Foreseen need for MRI to monitor or evaluate another chronic condition
* Previous experience with an implanted or trial neuromodulation system (spinal cord stimulation, peripheral nerve stimulation) for the treatment of pain at the index location
* Active local or systemic infection
* Actively in litigation for pain symptoms
* Currently on Workman's Compensation
* Women who are pregnant or intend to become pregnant during the study duration