Ep. 29 Ask US Anything (AUA-2)

Episode Summary: Understanding CRPS, Central Sensitization & Neuromodulation | Q&A with Dan and Justine

In this episode of 'It's Not In Your Head,' Dan and Justine answer your questions around various aspects of complex chronic pain management, focusing on Complex Regional Pain Syndrome (CRPS) and central sensitization. They delve into the Budapest criteria for diagnosing CRPS, the overlap with central sensitization, and treatments like spinal cord stimulators (SCS) and their pros and cons. Dan shares insights into managing pocket pain, complications associated with SCS, and innovative treatments like Prolotherapy. They also touch on the role of the sympathetic nervous system in CRPS and potential treatment avenues. It's a comprehensive episode packed with practical advice and cutting-edge information for both patients and providers dealing with complex pain pathologies.

Episode Overview:

Introduction & Episode Format

• Dan and Justine answer listener questions, focusing on complex chronic pain, especially CRPS (Complex Regional Pain Syndrome), central sensitization, and neuromodulation treatments.

Key Discussion Points

1. CRPS vs. Central Sensitization

• CRPS (Complex Regional Pain Syndrome):

  • Defined by the Budapest Criteria: ongoing, disproportionate pain post-injury, with additional symptoms (allodynia, hyperesthesia, vasomotor changes, swelling, motor changes, trophic changes).

  • Typically affects a limb or region; "whole body" CRPS is extremely rare.

• Central Sensitization:

  • Widespread hypersensitivity (pain, touch, sound, temperature, etc.).

  • Symptoms can overlap with CRPS but are more generalized.

  • Includes autonomic symptoms (abnormal sweating, GI/bladder issues, dizziness).

  • Defined in seven buckets

• Overlap:

  • Both involve hypersensitivity and disproportionate pain, but CRPS is usually focal, while central sensitization is more diffuse.

  • Fear of CRPS "spreading" often relates to increasing central sensitization.

2. Spinal Cord Stimulators (SCS) & Neuromodulation for CRPS

• Dr. Dan’s Perspective:

  • Uses neuromodulation (SCS, DRG stimulation) as a tool for neuropathic pain, including CRPS.

• Effectiveness:

  • Best evidence: ACCURATE study-70% of DRG patients and 50% of SCS patients achieve at least 50% pain relief (not pain-free).

  • Neuromodulation addresses part of the pain, especially the neuropathic component.

• Limitations:

  • Not a cure but a tool; does not address all pain or psychological aspects.

  • Should be part of a multidisciplinary approach (medication, physical therapy, lifestyle habits, psychological support).

• Patient Experience (Justine):

  • SCS can provide significant relief, enabling increased activity and quality of life.

  • Downsides: device complications, potential for new pain (e.g., from battery placement), and the need for ongoing management of compensations and complications

  • SCS is not always permanent-devices can be removed if not needed.

3. Complications and Management of SCS

• Common Issues:

  • Pocket pain (pain at battery/wire site), device malfunction, lead migration/fracture.

  • Management includes local treatments (patches, creams), device repositioning, or removal if necessary.

• Innovative Treatment:

  • Dr. Dan describes using 5% glucose (dextrose) injections for focal pocket pain-anecdotal but promising, with a low risk and cost.

  • The mechanism may involve TRPV1 receptor modulation, similar to treatments in carpal tunnel syndrome.

4. Vascular Changes in CRPS

• Symptoms: Bulging or receding veins, swelling, color changes.

• Mechanism: Sympathetic nervous system involvement affecting vascular tone and permeability.

• Implications: Indicates a sympathetic component, which can guide treatment (e.g., sympathetic nerve blocks, medications like clonidine, or ketamine infusions).

5. Timing & Guidelines for SCS

• Current Practice: Average time to SCS implant is 14 years post-pain onset-typically is peoples last resort after they’ve tried everything

• Guidelines: NICE (UK) recommends considering neuromodulation after 6 months of refractory neuropathic pain.

• Risks: Spinal cord injury (rare), infection, lead migration, device complications.

• Trial Period: A trial stimulator is used to assess effectiveness before permanent implantation.

6. Living with SCS and Chronic Pain

• Rehabilitation: SCS can open doors to physical and psychological recovery, but ongoing effort is needed

• Personal Growth: Both emphasize the importance of expanding life boundaries and not letting chronic pain define one’s limits.

Closing Notes

• Listeners are invited to submit questions for future episodes at @iniyhpodcast on Instagram or via email to danandjuz@iniyh.com