A 40-year-old man with disabling phantom limb pain after a traumatic transfemoral amputation has failed gabapentin and amitriptyline. He is started on mirror therapy. The proposed neurophysiological basis of this intervention is:

• A Blocking nociceptive input at the spinal dorsal horn gate
• B Restoring congruence between motor output and visual feedback to reverse cortical reorganisation ✓
• C Stimulating large-diameter afferents to activate descending inhibitory pathways
• D Desensitising the neuroma through repeated mechanical loading

Explanation

Mirror therapy provides illusory visual feedback of movement of the missing limb, restoring congruence between the motor command and what the brain sees. This is thought to reverse maladaptive cortical reorganisation in the sensorimotor cortex that maintains phantom pain. Option C describes TENS, and option A describes the gate control theory underlying TENS and counterstimulation, neither of which involves visual feedback.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.