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Upper Limb Neuro

Upper Limb Peripheral Mononeuropathy

February 15th, 2021


Peripheral mononeuropathy is a type of peripheral neuropathy affecting a single peripheral nerve.
  • Causes of Peripheral Mononeuropathy

  • Compression (particularly carpal tunnel and ulnar tunnel) - prolonged pressure, hereditary neuropathy with liability to pressure palsies (HNPP)
  • Trauma - blunt trauma, penetrating injury (e.g. knife, gunshot, glass)
  • Nerve ischaemia - trauma, thromboembolism, diabetes, atherosclerosis, excessive tourniquet use
  • Radiation injury
  • Peripheral Nerves of the Upper Limb

  • NerveSensoryMotor
    RadialSnuff box
    Anterior forearm + AC fossa (proximal lesion)
    Wrist drop
    Wrist extension
    Finger extension
    Elbow extension (proximal lesion)
    MedianPalmar aspect of thumb, 2nd & 3rd fingers
    Thenar eminence (proximal lesion)
    Hand of benediction
    Thumb abduction
    Wrist flexion & pronation (proximal lesion)
    Ulnar5th finger + medial 4th finger
    Ulnar aspect of forearm (proximal lesion)
    Claw hand
    Finger abduction
    Ulnar deviation (proximal lesion)
    MusculocutaneousLateral forearmElbow flexion
    AxillaryLateral upper armShoulder abduction, flexion & extension
    Long ThoracicNilScapular winging
    Shoulder elevation
    SuprascapularNilShoulder abduction & external rotation
    Spinal AccessorySuperior shoulderShoulder elevation & abduction

Radial Nerve Palsy

  • Signs of Radial Nerve Palsy

  • Sensory

  • Sensory loss over the snuff box
  • Anterior forearm & AC fossa (proximal lesion)
  • Motor

  • Wrist drop - inability to extend the wrist
  • Weakness of wrist extension and finger extension
  • Weakness of elbow extension (proximal lesion)
  • Radial Nerve Syndromes

  • Radial neuropathy at the spiral groove
  • Posterior interosseous syndrome - palsy affecting the posterior interosseous nerve, a branch of the radial nerve
  • Crutch palsy - prolonged crutch use resulting in compression of the radial nerve in the axilla
  • Saturday night palsy - compression of the radial nerve during sleep, usually while intoxicated
  • Handcuff neuropathy - radial neuropathy at the wrist

Median Nerve Palsy

  • Signs of Median Nerve Palsy

  • Sensory

  • Sensory loss over the palmar aspect of the thumb, 2nd and 3rd fingers
  • Sensory loss over the thenar eminence (proximal lesion)
  • Tinel's sign - percuss over the flexor retinaculum and ask about symptoms
  • Phalen's sign - reverse prayer position and ask about symptoms
  • Motor

  • Weakness of thumb abduction
  • Hand of benediction (proximal lesion) - inability to flex the index and middle fingers
  • Thenar eminence wasting (proximal lesion)
  • Weakness of wrist pronation and flexion (proximal lesion)
  • Inability to maintain an O between the thumb and index finger (proximal lesion)
  • Median Nerve Syndromes

  • Carpal tunnel syndrome - compression of the median nerve beneath the flexor retinaculum at the wrist
  • Pronator teres syndrome - entrapment of the median nerve by the pronator teres
  • Anterior interosseous syndrome - palsy affecting the anterior interosseous nerve, a branch of the median nerve
  • Causes of Carpal Tunnel Syndrome

  • Idiopathic
  • Trauma - Colle's fracture
  • Endocrine - hypothyroidism, acromegaly, diabetes
  • Rheumatoid arthritis
  • Amyloidosis
  • Gout
  • Pregnancy

Ulnar Nerve Palsy

  • Signs of Ulnar Nerve Palsy

  • Sensory

  • Sensory loss over the palmar and dorsal aspect of the 5th finger and medial half of the ring finger
  • Sensory loss of the ulnar aspect of the forearm (proximal lesion)
  • Motor

  • Claw hand - extension of the MCP joints and flexion of the IP joints of the ring and little fingers
  • Wasting of the small muscles of the hand (sparing the thenar eminance)
  • Weakness of finger abduction
  • Weakness of ulnar deviation of the wrist (proximal lesion)
  • Ulnar Nerve Syndromes

  • Cubital tunnel syndrome - trauma or compression of the ulnar nerve within the cubital tunnel at the elbow
  • Guyon's canal palsy (cyclist's palsy) - compression of the ulner nerve at the wrist
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