Neuropathies Main

Other Names

• Neuropathies Main
• Nerve Injury Main

---

Introduction

• This page summarizes
  • Neuropathies
• See: Neurology Main for concussion, seizures, headaches, etc
• See: Nerve Anatomy Main for a review of nerve anatomy

---

Terminology

Neurapraxia

• Definition: Mildest form of nerve injury; a temporary conduction block without structural damage to the axon.
• Pathophysiology: Myelin sheath may be damaged, but axon remains intact. No Wallerian degeneration.
• Causes: Compression, mild traction, ischemia.
• Symptoms:
  • Loss of motor function or sensation distal to injury
  • Usually transient, recovery occurs in days to weeks.
• Recovery: Full recovery usually within weeks.

Axonotmesis

• Definition: More severe injury; axon is damaged, but connective tissue (endoneurium, perineurium, epineurium) remains at least partially intact.
• Pathophysiology:
  • Axon undergoes Wallerian degeneration distal to injury
  • Schwann cells and connective tissue scaffolding remain, which guides regeneration
• Causes: Severe crush or prolonged compression injuries
• Symptoms:
  • Flaccid paralysis and loss of sensation distal to injury
  • Trophic changes may occur (skin, nails, hair)
• Recovery: Gradual, weeks to months; rate ~1–3 mm/day

Neurotmesis

• Definition: Most severe form; complete transection of axon and connective tissue
• Pathophysiology: Wallerian degeneration occurs; without surgical intervention, regeneration is poor or misdirected
• Causes: Sharp lacerations, severe trauma
• Symptoms:
  • Complete loss of motor and sensory function distal to injury
  • Trophic changes and muscle atrophy occur rapidly
• Recovery: Requires surgical repair; spontaneous recovery is unlikely

Related Terms

• Wallerian degeneration: Degeneration of the axon distal to the site of injury; occurs in axonotmesis and neurotmesis
• Conduction block: Interruption of nerve signal without axon damage; seen in neurapraxia
• Sunderland classification: More detailed 5-degree classification of nerve injuries
  • 1 = neurapraxia, 2 = axonotmesis, 3–4 = increasing connective tissue involvement, 5 = neurotmesis
• Neuropraxic segment: The part of nerve experiencing conduction block in neurapraxia
• Regeneration rate: Peripheral nerves regenerate ~1–3 mm/day after axonotmesis if scaffold intact

---

Upper Extremity Neuropathies

• Anterior Interosseous Nerve Syndrome
• Axillary Nerve Injury
• Carpal Tunnel Syndrome
• Cubital Tunnel Syndrome
• Guyon Canal Syndrome
• Parsonage Turner Syndrome
• Posterior Interosseus Nerve Syndrome
• Pronator Teres Syndrome
• Quadrilateral Space Syndrome
• Radial Nerve Injury
• Radial Tunnel Syndrome
• Saturday Night Palsy
• Suprascapular Nerve Injury
• Ulnar Nerve Neuropathies
  • Ulnar Nerve Injury
  • Cubital Tunnel Syndrome
  • Guyon Canal Syndrome
• Wartenbergs Syndrome
• Spinal Accessory Nerve Injury
• Median Nerve Injury

---

Spinal and Torso Neuropathies

• Cervical Cord Neuropraxia
• Cervical Myelopathy
• Cervical Radiculopathy
• Long Thoracic Nerve Injury
• Lumbar Radiculopathy
• Pudendal Nerve Injury
• Winged Scapula

---

Lower Extremity Neuropathies

• Baxters Neuropathy
• Fibular Nerve Injury
• Joggers Foot
• Meralgia Paresthetica
• Mortons Neuroma
• Obturator Nerve Injury
• Peroneal Nerve Injury (foot drop)
• Saphenous Nerve Entrapment
• Saphenous Nerve Injury
• Sural Nerve Injury
• Tarsal Tunnel Syndrome
• Femoral Nerve Injury
• Tibial Nerve Injury

---

Other

• Chronic Exertional Compartment Syndrome
• Acute Compartment Syndrome
• Complex Regional Pain Syndrome

---

See Also

• Neurology Main
• Nerve Anatomy Main

---