Peripheral nerve syndromes


Nerves of the left upper extremity.

Cervical Exam by Level

Radiculopathy Motor Deficit Sensory Deficit Diminished Reflex
C4 Levator Scapulae & Shoulder elevation
C5 Deltoid & Biceps Biceps
C6 Brachioradialis & Wrist extension Thumb Paresthesia Brachioradialis
C7 Triceps & Wrist flexion Index/Middle/Ring Paresthesia Triceps
C8 Index/Middle distal phlnx flexion Small Finger Paresthesia

Clinical Features

Cutaneous innervation of the upper limb
Lower limb peripheral innervation

Peripheral nerve syndromes

  • Upper extremity
    • Ulnar
      • Cause of Injury: Elbow injury.
      • Sensory changes in the 5th and medial half of 4th digits, weak wrist flexors, “claw hand”
    • Radial
    • Median, distal
      • Cause of Injury: Wrist dislocation, laceration, Carpal Tunnel Syndrome
      • Weak flexion of radial half of digits and thumb, loss of abduction and opposition of thumb. Ape hand deformity, benediction sign. Loss of sensation of lateral three and one-half digits and nail beds
    • Median, proximal
    • Musculocutaneous
      • Cause of Injury: Anterior shoulder dislocation, entrapment due to hypertrophy
      • Elbow flexion and supination weakness, radial forearm sensory deficits
    • Axillary
    • Suprascapular
      • Cause of Injury: Paralabral cyst, bone/soft tissue tumor, Scapular fracture, traction injury, Parsonage-Turner syndrome
      • Weak arm abduction to 90 degrees, weak shoulder flexion to 30 degrees, weak internal rotation
  • Lower extremity
    • Femoral
      • Cause of Injury: Pubic rami fracture, pelvic fractures
      • Weak knee extension, anterior knee sensory deficits
    • Obturator
    • Posterior tibial
      • Cause of Injury: Knee dislocation
      • Weak toe flexion, plantar foot sensory deficit
    • Superficial peroneal
      • Cause of Injury: Fibular neck fracture, knee dislocation
      • Weak ankle eversion, lateral dorsal foot sensory deficits
    • Deep peroneal
      • Cause of Injury: Fibular neck fracture, compartment syndrome
      • Sensory deficit at dorsal 1st web space, weak ankle and toe dorsiflexion
    • Sciatic
      • Cause of Injury: Posterior hip dislocation
      • Lower leg weakness, foot drop, leg sensory deficits
    • Superior gluteal
    • Inferior gluteal
      • Cause of Injury: Acetabular pelvic fracture, s/p hip replacement
      • Abnormal gait, gluteus maximus weakness resulting in gluteus maximus lurch

Differential Diagnosis

Nerve roots that supply sensation to the upper extremities.

Upper extremity peripheral nerve syndromes

Median Nerve Syndromes

Ulnar Nerve Syndromes

Radial Nerve Syndromes

Proximal Neuropathies


Extremity trauma




See Also