Median nerve

Question 1

Sites of entrapment

Answer 1

Can be 3 sites:
– elbow
– pronators teres
– wrist (carpal tunnel syndrome)

Question 2

Elbow

Answer 2

Occasionally compression due to sleeping on elbow

Medial supracondylar fractures

Signs and symptoms:
– Weakness in forearm and wrist pronation (supplies pronator teres and quadrates)
– weakness of wrist flexion
– ape hand deformity (atrophy or thenar muscles)
– loss of sensation to palm and palmar surface of lateral 3.5 fingers including posterior DIP joints

Question 3

Pronator teres muscle

Answer 3

– nerve runs through the ulnar head and humeral head of pronator teres
– known as pronator teres syndrome

– can find this out with:
– pronator teres muscle test, pronator stress test, tinnels sign at the pronator teres

Signs and symptoms:
– throbbing/aching in wrist and forearm
– weakness in gripping and holding objects
– pain with forearm pronation, pain with wrist flexion
– ape hand deformity
– loss of sensation to palm and palmar surface of lateral 3.5 fingers including posterior DIP’s

Question 4

Wrist (carpal tunnel syndrome)

Answer 4

Most commonly due to carpal tunnel syndrome

Possibly secondary to:
– lacerations
– puncture wounds

Signs and symptoms:
– ape hand deformity
– loss of sensation to palm and palmar surface of lateral 3.5 fingers including posterior DIP’s

– injury to median nerve through carpal tunnel syndrome, means loss of sensation to the palmar surface of the lateral 3.5 digits. However it DOES NOT affect the palm

—- this may help differentiate injury of the median nerve above the carpal tunnel and carpal tunnel syndrome