Phantom limb pain is a well-recognised complication after amputation. Which of the following mechanisms is currently considered the primary pathophysiological explanation for phantom limb pain?

• A Persistent activity of peripheral nociceptors in the stump causing referred pain to the amputated segment
• B Maladaptive cortical reorganisation in the primary somatosensory cortex (SI) with expansion of adjacent cortical representations into the deafferented area ✓
• C Psychological grief reaction to limb loss with no neurological basis
• D Sympathetically maintained pain from excessive noradrenaline release at stump end neuromas

Explanation

Phantom limb pain is primarily explained by maladaptive cortical plasticity. After amputation, the deafferented cortical area (e.g., hand/foot area in SI) is invaded by adjacent cortical representations (e.g., face or proximal limb), causing abnormal, misinterpreted somatosensory signals perceived as pain in the absent limb. This is supported by fMRI evidence showing degree of cortical reorganization correlates with phantom pain intensity. Stump neuroma activity (peripheral sensitization) contributes but is not the primary mechanism. Mirror visual feedback therapy, graded motor imagery, and virtual reality target cortical reorganization. Sympathetically maintained pain is a component of CRPS, not phantom pain.

Reference: Maheshwari Essential Orthopaedics, 6th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.