Peripheral nerve syndromes
Background
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
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
- Cause of Injury: Distal humeral shaft fracture, anterior shoulder dislocation, supra-condylar fracture, Radial neuropathy at the spiral groove, Posterior interosseous neuropathy
- “Wrist drop,” weakness of finger extensors. +/- sensory loss over the dorsum of the hand, weak thumb adduction
- 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
- Cause of Injury: Supracondylar humeral fracture, Pronator teres syndrome, Anterior interosseous neuropathy, tight cast
- See Median, distal above, loss of forearm pronation, loss of radial half digits and thumb flexion
- Musculocutaneous
- Cause of Injury: Anterior shoulder dislocation, entrapment due to hypertrophy
- Elbow flexion and supination weakness, radial forearm sensory deficits
- Axillary
- Cause of Injury: Anterior shoulder dislocation, inferior shoulder dislocation, proximal humerus fracture
- Weak arm abduction (from 15 to 90 degrees), weak shoulder flexion, extension and rotation of shoulder, loss of sensation of upper lateral arm
- 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
- Ulnar
- Lower extremity
- Femoral
- Cause of Injury: Pubic rami fracture, pelvic fractures
- Weak knee extension, anterior knee sensory deficits
- Obturator
- Cause of Injury: Obturator ring fracture, obturator nerve entrapment
- Weak hip adduction, medial thigh sensory deficit
- 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
- Cause of Injury: Acetabular pelvic fracture
- Trendelenburg’s gait, Trendelenburg’s sign
- Inferior gluteal
- Cause of Injury: Acetabular pelvic fracture, s/p hip replacement
- Abnormal gait, gluteus maximus weakness resulting in gluteus maximus lurch
- Femoral
Differential Diagnosis
Upper extremity peripheral nerve syndromes
Median Nerve Syndromes
Ulnar Nerve Syndromes
Radial Nerve Syndromes
- Radial neuropathy at the spiral groove (ie. "Saturday night palsy")
- Posterior interosseous neuropathy
Proximal Neuropathies
- Suprascapular neuropathy
- Long thoracic neuropathy
- Axillary neuropathy
- Spinal accessory neuropathy
- Musculocutaneous neuropathy
Other
Extremity trauma
- Compartment syndrome
- Contusion
- Crush syndrome
- Degloving injury
- Fracture
- Laceration
- Myositis ossificans
- Open joint injury
- Peripheral nerve injury
- Rhabdomyolysis
- Tendon injury
- Vascular injury
Evaluation
- Neurologic exam with focus on sensory component