A 25-year-old soldier undergoes trans-femoral (above-knee) amputation after blast injury. Three months post-surgery, he develops episodic severe burning pain in the phantom limb. The neurophysiological basis of phantom limb pain is best explained by:

• A Cortical reorganisation (maladaptive neuroplasticity) in the somatosensory cortex with ectopic spinal cord and supraspinal sensitisation ✓
• B Neuroma formation at the stump tip causing continuous peripheral afferent discharge
• C Sympathetically maintained pain from stump ischaemia
• D Psychological disorder requiring psychiatric treatment as primary management

Explanation

Phantom limb pain involves both peripheral (ectopic discharge from neuromas and dorsal root ganglia) and central mechanisms — cortical reorganisation (maladaptive remapping of the somatosensory cortex following deafferentation), dorsal horn sensitisation, and supraspinal changes. Mirror therapy, graded motor imagery, and NMDA antagonists (ketamine) target central sensitisation. Peripheral neuroma treatment alone is insufficient for established phantom pain because the central mechanisms predominate.

Reference: Maheshwari Essential Orthopaedics, 6th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.