Deep Brain Stimulation for Chronic Pain Treatment
Deep brain stimulation (DBS) has limited evidence supporting its efficacy for chronic, severe pain that has not responded to other therapies, with most data coming from retrospective series or prospective studies with significant methodological limitations. 1, 2
Current Evidence Base
- Evidence supporting neurostimulation therapies for chronic pain has been collected predominantly from retrospective series or from prospective studies with design limitations, lacking sufficient participants, matched control groups, sham stimulation, randomization, and prospectively defined endpoints 1, 3
- To date, there has been no successful clinical study establishing the efficacy of neurostimulation for pain that incorporates sufficient participant numbers, matched control groups, sham stimulation, randomization, prospectively defined endpoints, and methods for controlling experimental bias 3, 4
- Recent data provides tentative support for DBS as a treatment for chronic pain, but high-level evidence remains elusive 2
Efficacy by Pain Type
- DBS appears more effective for nociceptive pain than deafferentation pain (63% vs 47% long-term success) 5
- Higher success rates have been reported for specific conditions:
- Failed back surgery syndrome (>80% long-term success following successful trial stimulation) 5
- Phantom limb pain and neuropathies (higher success rates compared to other conditions) 5
- Post-stroke pain (approximately 50% success with trial stimulation, with 58% of permanently implanted patients achieving ongoing relief) 5
- Poorer outcomes have been observed in patients with:
Stimulation Targets
- Several brain targets have been used for DBS in pain treatment:
- Periventricular/periaqueductal gray matter (PVG/PAG) - 79% long-term pain alleviation 5
- Combined PVG/PAG plus sensory thalamus/internal capsule - 87% long-term success 5
- Sensory thalamus alone - 58% long-term success 5
- More recently, rostral anterior cingulate cortex has been used for whole or hemibody pain 7
Long-term Outcomes
- A ten-year follow-up study reported long-term pain control in 63% of patients 6
- There appears to be an initial 2-year fall-off of pain control due to tolerance development, with more stable results thereafter 6
- A meta-analysis found that DBS of the PVG/PAG or combined PVG/PAG plus sensory thalamus/internal capsule provided better long-term outcomes than sensory thalamus stimulation alone 5
Current Guidelines and Recommendations
- The American Society of Anesthesiologists (ASA) practice guidelines do not specifically endorse DBS for chronic pain management 1
- Current clinical guidelines classify DBS as having insufficient evidence for the routine treatment of chronic pain 4
- The procedure remains "off label" in the USA as it does not have FDA approval 8
Considerations for Patient Selection
- DBS may be considered for carefully selected patients with refractory chronic pain, particularly those with:
- Somatotopic coverage during awake surgery is important for optimal outcomes 7
Future Directions
- Ongoing and prospective clinical trials are exploring DBS for pain in the context of:
- Advanced neuroimaging techniques, including tractography, may help optimize electrode placement and clinical outcomes 8
DBS for chronic pain remains an investigational approach that should be considered only after failure of conventional therapies. The procedure's success depends on proper patient and intracranial target selection, with ongoing research needed to better define its role in pain management.