Bracial Plexus

Question 0

Median Nerve

Answer 0

• C5-T1
• “Ape hand” and “Pope’s blessing”
• Loss of wrist and lateral finger flexion, thumb opposition, lumbracals of 2nd and 3rd digits
• Loss of sensation over thenar eminence and dorsal and palmar aspects of lateral 3 1/2 fingers with proximal lesion
• Tinel sign (tingling on percussion) in carpal tunnel syndrome
• Supracondylar fracture of humerus (proximal lesions)
• carpal tunnel syndrome and wrist laceration (distal lesion)

Question 1

Radial Nerve

Answer 1

• C5-T1, “wrist drop”: loss of elbow, wrist, and finger extension
• loss of sensation over the posterior arm/forearm and dorsal hand
• less grip strength(wrist extension necessary for maximal grip strength)
• Midshaft fracture of humerus
• compression of axilla (e.g., due to crutches or sleeping with arm over chair (“Saturday night palsy”)

Question 2

Axillary nerve

Answer 2

• C5-C6
• Fractured surgical neck of the humerus
• anterior dislocation of humerus
• Flattened deltoid
• Loss of arm abduction at shoulder (> 15 degrees)
• Loss of sensation over deltoid muscle and lateral arm

Question 3

Musculocutaneous nerve

Answer 3

• C5-C7
• Upper trunk compression
• Loss of forearm flexion and supination
• Loss of sensation over lateral forearm

Question 4

Ulnar nerve

Answer 4

• C8-T1
• Fracture of the medial epicondyle of the humerus “funny bone”
• Fracture of hamate
• “Ulnar claw” and digit extension
• Radial deviation of wrist upon flexion (proximal lesion)
• Loss of flexion of wrist and medial fingers, abduction and adduction of fingers (interossei), actions of medial 2 lumbrical muscles
• Loss of sensation over medial 1 1/2 fingers including hypothenar eminence

Question 5

Recurrent branch of median nerve

Answer 5

• C5-T1
• “Ape hand”
• Superficial laceration of palm
• Loss of thenar muscle group: opposition, abduction, and flexion of thumb
• No loss of sensation