A 30-year-old motorcyclist sustains a high-energy brachial plexus injury. Clinical assessment reveals complete loss of shoulder abduction (deltoid), elbow flexion (biceps), and wrist/finger extension. MRI shows pseudomeningoceles at C5, C6, C7 levels. The finding of pseudomeningoceles signifies which type of injury that is irreparable by direct nerve repair?

• A Post-ganglionic rupture amenable to cable grafting
• B Pre-ganglionic avulsion from the spinal cord, not amenable to direct repair ✓
• C Neuropraxia with expected spontaneous recovery within 6 weeks
• D Axonotmesis with intact endoneurium allowing guided regeneration

Explanation

Pseudomeningoceles on MRI are formed when nerve roots avulse from the spinal cord, tearing the dural sleeve and allowing CSF to fill the resultant cavity. This represents pre-ganglionic avulsion — the root is detached from the spinal cord, which cannot regenerate. Direct nerve repair is impossible. These injuries require nerve transfer (neurotization) techniques: using donor nerves (intercostal, phrenic, contralateral C7, spinal accessory, medial pectoral, thoracodorsal, hypoglossal) to re-innervate target muscles. Post-ganglionic ruptures at C5-C6 are repairable with cable grafts because the spinal cord connection is intact.

Reference: Maheshwari Essential Orthopaedics, 6th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.