USMLE MSK Nerve Injuries


Upper Extremity Nerve Injuries
Nerve | Answer | Question | Number |
---|---|---|---|
Axillary | C5-6 | Nerve Roots | 2 |
Radial | C5-T1 | Nerve Roots | 5 |
Median | C5-T1 | Nerve Roots | 5 |
Ulnar | C8-T1 | Nerve Roots | 2 |
Musculocutaneous | C5-7 | Nerve Roots | 3 |
Axillary | Fractured surgical neck of humerus/dislocation of humeral head | Typical injury | 2 |
Radial | Fractured midshaft of humerus/compression of axilla by chair-crutches | Typical injury | 2 |
Median | Fracture of supracondylar humerus | Typical injury | 1 |
Ulnar | Fracture of epicondyle of humerus | Typical injury | 1 |
Musculocutaneous | Upper trunk compression | Typical injury | 1 |
Axillary | Deltoid (arm abduction) | Motor deficit | 1 |
Radial | BEST/Brachioradialis/Extensors/Supinator/Triceps | Motor deficit | 4 |
Median | Opposition of thumb/Lateral finger flexion/wrist flexion | Motor deficit | 3 |
Ulnar | Medial finger flexion/wrist flexion | Motor deficit | 2 |
Musculocutaneous | Biceps/brachialis/coracobrachialis (flexion of elbow) | Motor deficit | 3 |
Axillary | Over deltoid | Sensory deficit | 1 |
Radial | Posterior arm/dorsal hand-thumb | Sensory deficit | 2 |
Median | Dorsal-palmar lateral 3.5 fingers/thenar eminence | Sensory deficit | 2 |
Ulnar | Medial 1.5 fingers/hypothenar eminence | Sensory deficit | 2 |
Musculocutaneous | Lateral forearm | Sensory deficit | 1 |
Axillary | Atrophied deltoid | Sign | 1 |
Radial | Wrist drop | Sign | 1 |
Median | Ape hand (loss of opponens pollicis)/Pope's hand (open digits 1-3 when trying to make fist) | Sign | 2 |
Ulnar | Radial deviation of wrist upon flexion/claw hand | Sign | 2 |
Long thoracic | C5-7 | Nerve Roots | 3 |
Long thoracic | Mastectomy | Typical injury | 1 |
Long thoracic | Serratus anterior (abduction above horizontal) | Motor deficit | 1 |
Long thoracic | Winged scapula/ipsilateral lymphedema | Sign | 2 |
Lower Extremity Nerve Injuries
Nerve | Answer | Question | Number |
---|---|---|---|
Obturator | L2-L4 | Nerve Roots | 3 |
Femoral | L2-L4 | Nerve Roots | 3 |
Common peroneal | L4-S2 | Nerve Roots | 4 |
Tibeal | L4-S3 | Nerve Roots | 5 |
Superior gluteal | L4-S1 | Nerve Roots | 3 |
Inferior gluteal | L5-S2 | Nerve Roots | 3 |
Obturator | Anterior hip dislocation | Typical injury | 1 |
Femoral | Pelvic fracture | Typical injury | 1 |
Common peroneal | Trauma-compression of lateral aspect of leg/fibula neck fracture | Typical injury | 2 |
Tibeal | Knee trauma | Typical injury | 1 |
Superior gluteal | Posterior hip dislocation/polio | Typical injury | 2 |
Inferior gluteal | Posterior hip dislocation | Typical injury | 1 |
Obturator | Thigh adduction | Motor deficit | 1 |
Femoral | Thigh flexion/leg extension | Motor deficit | 2 |
Common peroneal | Foot eversion/dorsiflection/toe extension | Motor deficit | 3 |
Tibeal | Foot inversion/plantarflexion/toe flexion | Motor deficit | 3 |
Superior gluteal | Thigh abduction (gluteus medius/minimus) | Motor deficit | 2 |
Inferior gluteal | Gluteus maximus | Motor deficit | 1 |
Obturator | Medial thigh | Sensory deficit | 1 |
Femoral | Anterior thigh/medial leg | Sensory deficit | 2 |
Common peroneal | Anterolateral leg/dorsal foot | Sensory deficit | 2 |
Tibeal | Sole of foot | Sensory deficit | 1 |
Common peroneal | Foot drop/foot slap/steppage gait | Sign | 3 |
Superior gluteal | Trendelenburg (Contralateral hip drops on standing on leg ipsilateral to injury) | Sign | 1 |
Inferior gluteal | Cant jump/climb stairs/rise from seated | Sign | 3 |
Sciatic nerve | L4-S3 | Nerve Roots | 5 |
Sciatic nerve | Posterior thigh | Typical injury | 1 |
Sciatic nerve | All of common peroneal/tibial | Motor deficit | 2 |
Sciatic nerve | All of common peroneal/tibial | Sensory deficit | 2 |
Brachial plexus lesions
Nerve | Answer | Question | Number |
---|---|---|---|
Upper trunk | C5-C6 | Nerve Roots | 2 |
Upper trunk | Delivery trauma | Typical injury | 1 |
Upper trunk | Paralysis of abductors/lateral rotators/biceps | Motor deficit | 3 |
Upper trunk | Erb-Duchenne palsy/Waiter's tip (limb by side/medially rotated/forearm pronated) | Sign | 2 |
Lower trunk | C8-T1 | Nerve Roots | 2 |
Lower trunk | Thoracic outlet syndrome/pancoast tumor of lung | Typical injury | 2 |
Lower trunk | Thenar/hypothenar eminences/interosseous | Motor deficit | 3 |
Lower trunk | Medial forearm/hand | Sensory deficit | 2 |
Lower trunk | Klumpke's palsy/total claw hand/loss of radial pulse on ipsilateral head rotation | Sign | 3 |
Posterior cord | C5-T1 | Nerve Roots | 5 |
Posterior cord | Fractured midshaft of humerus/compression of axilla by chair-crutches | Typical injury | 2 |
Posterior cord | BEST/Brachioradialis/Extensors/Supinator/Triceps | Motor deficit | 4 |
Posterior cord | Posterior arm/dorsal hand-thumb | Sensory deficit | 2 |
Posterior cord | Wrist drop | Sign | 1 |
Long thoracic | C5-7 | Nerve Roots | 3 |
Long thoracic | Mastectomy | Typical injury | 1 |
Long thoracic | Serratus anterior (abduction above horizontal) | Motor deficit | 1 |
Long thoracic | Winged scapula/ipsilateral lymphedema | Sign | 2 |
Axillary | C5-6 | Nerve Roots | 2 |
Axillary | Fractured surgical neck of humerus/dislocation of humeral head | Typical injury | 2 |
Axillary | Deltoid (arm abduction) | Motor deficit | 1 |
Axillary | Over deltoid | Sensory deficit | 1 |
Axillary | Atrophied deltoid | Sign | 1 |
Radial nerve | C5-T1 | Nerve Roots | 5 |
Radial nerve | Fractured midshaft of humerus/compression of axilla by chair-crutches | Typical injury | 2 |
Radial nerve | BEST/Brachioradialis/Extensors/Supinator/Triceps | Motor deficit | 4 |
Radial nerve | Posterior arm/dorsal hand-thumb | Sensory deficit | 2 |
Radial nerve | Saturday night palsy (wrist drop) | Sign | 1 |
Musculocutaneous nerve | C5-7 | Nerve Roots | 3 |
Musculocutaneous nerve | Biceps/brachialis/coracobrachialis (flexion of elbow) | Motor deficit | 3 |
Musculocutaneous nerve | Variable | Sensory deficit | 1 |
Median nerve | C5-T1 | Nerve Roots | 5 |
Median nerve-proximal | Fracture of supracondylar humerus | Typical injury | 1 |
Median nerve-proximal | Decreased thumb opposition/finger flexion | Motor deficit | 2 |
Median nerve-proximal | Pope's blessing (upon flexion only 4th/5th digits flex/1-3 remain extended) | Sign | 1 |
Median nerve-distal | Carpal tunnel/dislocated lunate | Typical injury | 2 |
Median nerve-distal | Loss of lateral lumbricles (2-3) | Motor deficit | 1 |
Median nerve-distal | Median claw (2nd-3rd fingers claw when attempting to extend hand) | Sign | 1 |
Ulnar nerve | C8-T1 | Nerve Roots | 2 |
Ulnar nerve-proximal | Fracture of epicondyle of humerus | Typical injury | 1 |
Ulnar nerve-proximal | Medial finger flexion/wrist flexion | Motor deficit | 2 |
Ulnar nerve-proximal | Medial 1.5 fingers/hypothenar eminence | Sensory deficit | 2 |
Ulnar nerve-proximal | Radial deviation of wrist upon flexion/claw hand | Sign | 2 |
Ulnar nerve-distal | Falling onto oustretched hand | Typical injury | 1 |
Ulnar nerve-distal | Loss of medial lumbricles | Motor deficit | 1 |
Ulnar nerve-distal | Ulnar claw (4th-5th digits cannot extend when attempting to open hand) | Sign | 1 |