Trigger point-related sympathetic nerve activity in chronic sciatic leg pain: a case study

Area of Science:

• Pain Medicine
• Autonomic Neuroscience
• Medical Imaging

Background:

• Sciatica is typically linked to sciatic nerve irritation from vertebral discs.
• Myofascial pain syndrome, involving active trigger points, can present with similar symptoms.
• The vasomotor response of active trigger points remains largely unexamined.

Observation:

• A case study of a 22-year-old man with chronic sciatic-type pain and diagnosed myofascial pain syndrome.
• Infrared thermovisual imaging was used to observe changes during acupuncture needle stimulation of active trigger points.
• A sudden, short-term vasodilation was observed in the area of referred pain following needling.

Findings:

• The observed vasodilation spread significantly (0.2 to 171.9 cm²).
• Post-needling, increased average and maximum skin temperatures were recorded in the thigh and calf.
• This vasodilation is hypothesized as an autonomic phenomenon linked to active trigger points.

Implications:

• This finding suggests a potential link between active trigger points and autonomic responses in referred pain.
• Further research is needed to confirm if this vasodilation occurs consistently in patients with active trigger points.
• The results may encourage broader investigation into myofascial pain syndrome's role in sciatic-like pain.