What is the effect of shockwave therapy on peripheral neuropathy?

Effects of Extracorporeal Shock Wave Therapy on Peripheral Neuropathy

Extracorporeal shock wave therapy (ESWT) appears to be safe and potentially effective for peripheral neuropathy, with evidence suggesting it may enhance peripheral nerve remyelination and improve nerve conduction, though it should not be considered first-line therapy for most neuropathic conditions.

Mechanism of Action

ESWT uses acoustic shock waves to create structural and neurochemical alterations that may:

• Reduce pain and promote tendon healing 1
• Enhance peripheral nerve remyelination 2
• Upregulate mechanical sensitive YAP/TAZ signaling pathway, which appears important for nerve regeneration 3
• Improve nerve conduction parameters, particularly in sensory nerves 4

Evidence for Different Types of Neuropathy

Diabetic Peripheral Neuropathy

• ESWT is listed as a biophysical modality for advanced wound care in diabetic foot ulcers 1
• While not considered first-line therapy for diabetic neuropathy, it may be considered when conventional treatments fail
• First-line treatments for painful diabetic neuropathy should include:
  • Pregabalin (300-600 mg/day)
  • Duloxetine (60-120 mg/day)
  • Gabapentin (900-3600 mg/day) 5

Chemotherapy-Induced Peripheral Neuropathy (CIPN)

• Current guidelines do not recommend ESWT for CIPN prevention or treatment
• For CIPN, duloxetine is the only agent with sufficient evidence for treatment of established painful CIPN 1
• Other treatment options with limited evidence include:
  • Gabapentin (despite limited evidence)
  • Topical gel containing baclofen, amitriptyline HCL, and ketamine 1

Carpal Tunnel Syndrome

• Research suggests ESWT may be beneficial for carpal tunnel syndrome when combined with conservative treatment
• In one study, patients receiving ESWT showed significant improvement in parameters after 3 months, with results maintained at 6 months 6

Potential Benefits

• Non-invasive treatment option
• Improved nerve conduction parameters, especially in sensory nerves 4
• Enhanced peripheral nerve remyelination 2
• Functional recovery improvements in animal models 2, 3

Potential Risks and Limitations

• Possible peripheral nerve injury at the site of application, as demonstrated in a case report of ulnar neuropathy after ESWT 7
• Limited high-quality evidence for many neuropathic conditions
• Not FDA-approved specifically for peripheral neuropathy treatment
• Optimal treatment protocols (energy levels, number of sessions) not well established

Treatment Considerations

When considering ESWT for peripheral neuropathy:

1. Rule out contraindications:

   • Pregnancy
   • Local malignancy
   • Blood clotting disorders
   • Pacemakers in the treatment area

2. Treatment parameters:

   • Typical protocol: 1 session per week for 3-4 weeks
   • Energy levels may be gradually increased (e.g., 0.05-0.15 mJ/mm²)
   • Shock numbers typically range from 800-1100 per session 6

3. Monitoring:

   • Assess nerve conduction studies before and after treatment
   • Evaluate functional outcomes and symptom improvement

Clinical Approach

ESWT should be considered as part of a comprehensive treatment approach:

1. For diabetic neuropathy: Optimize glucose control first, then consider FDA-approved medications (pregabalin, duloxetine) before ESWT 5

2. For CIPN: Consider duloxetine as first-line treatment; ESWT may be an option when standard treatments fail 1

3. For entrapment neuropathies (like carpal tunnel syndrome): Consider ESWT as an adjunct to conservative treatments 6

Conclusion

While ESWT shows promise for peripheral neuropathy treatment, particularly for enhancing nerve remyelination and improving sensory nerve conduction, it should generally be considered after first-line pharmacological treatments have failed. More research is needed to establish optimal treatment protocols and determine which neuropathy subtypes respond best to this therapy.