Nerve Palsies In The Limbs

Question 1

What are the clinical features involved in brachial plexus lesions?

Answer 1

Brachial plexus

• Erb’s palsy C5,6: shoulder adducted and internally rotated, elbow extended and pronates, wrist is flexed
• Klumpke’s palsy C8, T1: small muscles of the hand (claw hand)
• Total Brachial Plexus C5-T1

Peripheral nerves

• axillary (supplies deltoid and teres minor and regimental badge area, leads to deficits/atrophy)
• radial (depends on site of lesion. Axilla = loss of elbow, wrist extension and sensory changes in forearm and hand. Arm = loss of wrist extension, sensory loss. Wrist = sensory loss)
• median (carpal tunnel)
• ulnar (cubital tunnel)

Question 2

How is the lower limb innervated and what are the effects of nerve injury?

Answer 2

Innervated via sacral plexus (>sciatic > Common peroneal > tibial) and lumbar plexus (> femoral)

Injury may lead to foot drop, paraesthesia, deficits/wasting

Question 3

What are the common nerve entrapment syndromes?

Answer 3

Carpal tunnel syndrome:
- nocturnal pain and parasthesia in part or all of median nerve distribution
- wasting of thenar muscles
LOOK for thenar wasting, previous scars, deformity. FEEL sensation, MOVE APB power. SPECIAL TESTS eg tinnels, phalens.

Cubital tunnel syndrome:
- numbness on ulnar side, difficulty with fine tasks
LOOK 1st webspace wasting, guttering, hypothenar wasting. FEEL sensation. MOVE. SPECIAL TESTS eg froments