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Peripheral Nerve Injuries

Oct 30, 20252 min read

Peripheral Nerve Injuries

Prof. Mamoun Kremli Dr. Tarif Al-Akhras

Learning Objectives

  • Outline types of peripheral nerve injuries
  • Understand the reaction of peripheral nerves to injury
  • Identify and manage common peripheral nerve injuries:
    • Brachial plexus
    • Axillary nerve
    • Radial nerve
    • Ulnar nerve
    • Median nerve
    • Sciatic nerve
    • Common peroneal nerve

TOC

Summary and Key Points

Classification of Peripheral Nerve Injuries

  • Neuropraxia: Transient conduction block with excellent prognosis
  • Axonotmesis: Axonal damage with intact connective tissue, good recovery potential
  • Neurotmesis: Complete nerve transection requiring surgical intervention

Pathophysiology of Nerve Injury

  • Wallerian degeneration: Progressive degeneration of distal axon segments
  • Regeneration: Axonal regrowth at approximately 1mm/day from proximal stump
  • Regeneration challenges: Misdirected growth, axonal loss, time-dependent complications

Clinical Assessment Approach

  • Comprehensive history: Mechanism of injury, symptom progression
  • Physical examination: Motor testing, sensory evaluation, reflex assessment
  • Diagnostic studies: Nerve conduction studies, EMG, imaging when indicated

Common Peripheral Nerve Injuries

Upper Extremity

  • Brachial plexus injuries:

    • Erb’s palsy (C5-C6): Upper plexus lesions
    • Klumpke’s palsy (C8-T1): Lower plexus lesions
    • Total plexus: Complete upper extremity involvement

  • Axillary nerve:

    • Shoulder dislocations and humeral neck fractures
    • Deltoid weakness and sensory loss over lateral arm

  • Radial nerve:

    • Humeral shaft fractures, compression injuries
    • Wrist and finger drop with variable sensory loss

  • Median nerve:

    • “Ape hand” deformity with thenar wasting
    • Sensory loss in lateral 3½ fingers

  • Ulnar nerve:

    • Elbow fractures, compression at cubital tunnel
    • Claw hand deformity with intrinsic muscle weakness
    • Ulnar paradox: Less clawing in high lesions

Lower Extremity

  • Sciatic nerve:

    • Hip dislocations, pelvic fractures, iatrogenic injuries
    • Complete lower extremity paralysis below the knee

  • Common peroneal nerve:

    • Fibular neck fractures, compression injuries
    • Foot drop with characteristic gait abnormalities

Special Clinical Syndromes

  • Carpal Tunnel Syndrome: Median nerve compression at wrist
  • Anterior Interosseous Syndrome: Isolated motor median nerve branch involvement

Management Principles

  • Early recognition and accurate diagnosis
  • Conservative management for neuropraxia and axonotmesis
  • Surgical intervention for neurotmesis and certain ruptures
  • Rehabilitation: Maintain joint mobility and muscle readiness
  • Patient education: Realistic expectations for recovery timeline

Graph View

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