Acupuncture--self-appraisal and the reward system

Area of Science:

• Neuroscience
• Integrative Medicine
• Psychology

Background:

• Acupuncture is an ancient therapy with diverse physiological effects on the nervous system.
• Clinical trials often focus on specific techniques, overlooking the subjective experience and reward system activation.
• The 'placebo' aspect of acupuncture is complex, involving self-appraisal and expectation.

Purpose of the Study:

• To explore the neurobiological underpinnings of acupuncture's therapeutic effects, including pain relief and pleasurable sensations.
• To investigate the role of self-appraisal, reward pathways, and cognitive-affective networks in acupuncture response.
• To re-evaluate the concept of 'placebo needling' in light of neurophysiological evidence.

Main Methods:

• Review of physiological effects of acupuncture on peripheral and central nervous systems.
• Analysis of brain activation patterns related to acupuncture stimulation and patient expectations.
• Examination of the interplay between affective and cognitive neural pathways in treatment response.

Main Results:

• Both superficial and deep needling, including 'de qi/Hibiki,' ameliorated patellofemoral pain.
• Pleasurable aspects of acupuncture are linked to reward system activation via limbic structures.
• Self-appraisal processes involve integrated affective (ventral medial prefrontal cortex-limbic) and cognitive (dorsal medial prefrontal cortex-hippocampal) pathways.
• Long-term pain relief (6 months) in patellofemoral pain patients was observed.
• The cortical-cerebellar system plays a role in learning and maintaining long-term effects like pain alleviation.
• Activation/deactivation of cortical and subcortical structures occurs regardless of needling site, challenging the notion of inert sham acupuncture.

Conclusions:

• Acupuncture's efficacy, including long-term pain relief, involves complex neurobiological mechanisms beyond simple sensory input.
• The subjective experience, reward system activation, and cognitive-affective networks significantly contribute to acupuncture's therapeutic outcomes.
• The concept of 'placebo needling' is invalid, as all needling appears to activate relevant neural pathways, influencing the patient's perception and response.