Therapeutic Mechanisms of Epidural Spinal Cord Stimulation
Study Details
Study Description
Brief Summary
The purpose of the study is determine 1) whether Spinal Cord Stimulation (SCS) reduces arterial blood pressure (BP) in patients with chronic low back pain and hypertension, 2) whether higher baseline BP (i.e., hypertension) predicts reductions in pain following SCS, 3) whether SCS alters serological markers related to autonomic and renal function (measured by blood test), and 4) whether different SCS waveforms produce different electrical changes at the spinal cord and at the brain (measured from stimulation wire and by electroencephalography, EEG).
| Condition or Disease | Intervention/Treatment | Phase |
|---|---|---|
|
N/A |
Detailed Description
The purpose of this study in patients undergoing routine care epidural spinal cord stimulation (SCS) is to determine 1) whether SCS reduces arterial blood pressure (BP) in patients which chronic low back pain and hypertension, 2) whether higher baseline BP (i.e., hypertension) predicts reductions in pain following SCS, 3) whether SCS alters autonomic and renal function (laboratory markers), and finally 4) whether different SCS waveforms elicits stimulus-evoked compound action potentials (ECAPs) in spinal cord and at the cortex (electroencephalography, EEG).
The Investigators will identify patients with chronic pain who are scheduled for SCS implant at the University of Alabama at Birmingham for management of chronic neuropathic pain as part of routine care. The research team will assess BP with an arm cuff and take blood via blood draw during clinic visits before and after the implant among patients providing written informed consent. A blood draw will also be performed to examine changes in important blood chemistries related to blood pressure.
The Investigators' central clinical hypothesis is that SCS decreases blood pressure in patients with chronic pain and comorbid hypertension. The Investigators further hypothesize that the SCS will improve serological markers of sympathetic nerve activity and kidney function, possibly due to reductions in spinal cord sympathetic nerve activity. A secondary hypothesis is that higher baseline blood pressure predicts larger reductions in blood pressure following SCS implant.
Additionally, this project seeks to expand knowledge on therapeutic mechanisms of SCS via recording electrophysiological responses at the spinal cord (via adjacent, unused SCS contacts) and from EEG scalp recordings over the cerebral cortex.
Study Design
Arms and Interventions
| Arm | Intervention/Treatment |
|---|---|
| Experimental: Treatment Patients that proceed with permanent implantation of a spinal cord stimulator. |
Device: Permanent Epidural Spinal Cord Stimulation
Permanent Spinal Cord Stimulation implanted in participants undergoing routine care for management of chronic neuropathic pain.
|
| No Intervention: Control Patients who do not proceed with permanent implantation of a spinal cord stimulator. |
Outcome Measures
Primary Outcome Measures
- Arterial Blood Pressure Change [Baseline (1 week pre-op)]
The research team will assess systolic and diastolic blood pressure with an arm cuff.
- Arterial Blood Pressure Change [Visit 3 (7-10 days post-op)]
The research team will assess systolic and diastolic blood pressure with an arm cuff.
- Arterial Blood Pressure Change [Visit 4 (3-4 weeks post-op)]
The research team will assess systolic and diastolic blood pressure with an arm cuff.
- Arterial Blood Pressure Change [Visit 5 (7-8 weeks post-op)]
The research team will assess systolic and diastolic blood pressure with an arm cuff.
- Laboratory Markers - Catecholamines [Baseline (1 week pre-op)]
Blood will be collected for analysis of Catecholamines: dopamine, norepinephrine, and epinephrine and Catechol-O-methyltransferase.
- Laboratory Markers - Catecholamines [Visit 3 (7-10 days post-op)]
Blood will be collected for analysis of Catecholamines: dopamine, norepinephrine, and epinephrine and Catechol-O-methyltransferase.
- Laboratory Markers - Catecholamines [Visit 4 (3-4 weeks post-op)]
Blood will be collected for analysis of Catecholamines: dopamine, norepinephrine, and epinephrine and Catechol-O-methyltransferase.
- Laboratory Markers - Catecholamines [Visit 5 (7-8 weeks post-op)]
Blood will be collected for analysis of Catecholamines: dopamine, norepinephrine, and epinephrine and Catechol-O-methyltransferase.
- Laboratory Markers - COMT [Baseline (1 week pre-op)]
Blood will be collected for Catechol-O-methyltransferase (COMT) analysis.
- Laboratory Markers - COMT [Visit 3 (7-10 days post-op)]
Blood will be collected for Catechol-O-methyltransferase (COMT) analysis.
- Laboratory Markers - COMT [Visit 4 (3-4 weeks post-op)]
Blood will be collected for Catechol-O-methyltransferase (COMT) analysis.
- Laboratory Markers - COMT [Visit 5 (7-8 weeks post-op)]
Blood will be collected for Catechol-O-methyltransferase (COMT) analysis.
- Stimulus-Evoked Compound Action Potentials (ECAPS) - Spinal Cord [Visit 2 (intra-op)]
During stimulation sessions, unused SCS channels and EEG will be used to record local and distant stimulus-evoked activity. Participants will undergo a series of single pulses of stimulation to investigate the pattern of local neural recruitment at amplitudes inside and outside of the therapeutic window at tonic stimulation frequencies.
- Stimulus-Evoked Compound Action Potentials (ECAPS) - Cortex [Visit 2 (intra-op)]
During stimulation sessions EEG will be used to record distant stimulus-evoked activity. Participants will undergo a series of single pulses of stimulation to investigate the pattern of local and distant neural recruitment at standard clinical tonic and high frequencies.
Eligibility Criteria
Criteria
Inclusion Criteria:
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Male or Female, age 30-89
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Chronic pain for more than 3 months
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Willing to visit a research lab
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Willing to undergo a blood draw
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Able to provide written informed consent
Exclusion Criteria
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History of neurological disease (e.g., dementias, Parkinson's)
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History of stroke
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Current diagnosis of cancer
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Subject is unwilling or unable to comply with the protocol
Contacts and Locations
Locations
| Site | City | State | Country | Postal Code | |
|---|---|---|---|---|---|
| 1 | University of Alabama at Birmingham | Birmingham | Alabama | United States | 35233 |
Sponsors and Collaborators
- University of Alabama at Birmingham
Investigators
- Principal Investigator: Marshall Holland, MD, The University of Alabama at Birmingham
Study Documents (Full-Text)
None provided.More Information
Publications
None provided.- IRB-300009200