Changes in Cerebral Blood Flow in Patients Treated With Spinal Cord Stimulation for Low Back and Leg Pain

Changes in Regional Cerebral Blood Flow as an Indicator of Neuronal Activity in Patients Treated With Spinal Cord Stimulation for Low Back and Leg Pain

The primary objective of this study is to identify the brain regions in which activity is affected by SCS. Baseline cerebral blood flow scans with the device turned off will be generated compared to scans produced with the device operating at parameters which produce optimal coverage of the painful areas. The relationship between cerebral blood flow and pain rating scores will be evaluated in both conditions.

Spinal Cord Stimulation (SCS) is known to be effective in pain management. Some evidence exists that SCS may cause changes in cerebral blood flow. This study will be a novel PET examination of activity in brain regions affected by SCS. This activity will be compared with the pain intensity and distribution. Further, by examining cerebral blood flow at different doses of stimulation, relationships between SCS, brain perfusion, and pain relief can be drawn. This study will contribute to the elucidation of the mechanism of action of SCS.

Inclusion Criteria:

• Have had one or more back surgery procedures.
• Have used an active Precision SCS device for chronic low back and bilateral leg pain for at least 6 weeks.
• Have bilateral leg pain.
• Have a baseline VAS of >4 (without stimulation).
• Have greater than 50% reduction in pain with SCS at optimal settings
• Be 18 years of age or older.
• Have the cognitive and functional capability to operate the controls for the device, to comply with directions during the study, and willing to participate in all study activities.
• Be capable of reading and understanding patient information materials and giving written informed consent.

Exclusion Criteria:

• Have any significant medical condition that is likely to interfere with study procedures or likely to confound evaluation of study endpoints.
• Have undergone a surgical lead revision or had any Precision components replaced after initial implantation.
• Are allergic to any of the injected media.
• Are pregnant or lactating.
• Have any contraindication to the PET scan procedure itself or exposure to the intravenous radioactive tracer (H215O).
• Have participated in any drug or device trial in the last 4 weeks or are currently participating in another drug or device trial.