Mononeuropathies

Question 1

What are the features of a radial neuropathy?

Answer 1

• Most common cause is entrapment at spinal groove
• Wrist and finger drop
• Extensor carpi radialis (wrist extension), extensor digitorum communis (finger extension) and brachioradialis (elbow flexion in mid-pronation) weakness

Question 2

What are the features of an ulnar neuropathy?

Answer 2

• Most common cause is entrapment at ulnar groove (medial epicondyle of humerus)
• Hx of trauma at elbow, sensory disturbance and weakness (weak grip)
• 1st dorsal interosseus (index finger abduction), abductor digiti minimi (pinkie abduction), flexor carpi ulnaris (wrist flexion) and adductor pollicus (thumb adduction) weakness

Question 3

What are the features of a median neuropathy?

Answer 3

• Most common cause is entrapment within carpal tunnel at wrist
• Hx of intermittent nocturnal pain, numbness and tingling (often relieved by shaking hand), weak grip and positive Tinel’s sign/Phalen’s test
• Lumbricals I + II (flexion at MCP joints), opponens pollicis (thumb opposition), abductor pollicus brevis (thumb abduction) and flexor pollicus brevis (thumb flexion) weakness

Question 4

What are the features of a median (anterior interosseous branch) neuropathy?

Answer 4

• Most common cause is trauma to forearm
• Forearm pain, weak grip of keys and positive Tinel’s sign/Phalen’s test
• Pronator quadratus (flexion at MCP joints), flexor pollicus longus (thumb flexion) and flexor digitorum profundus lateral (thumb flexion) weakness

Question 5

What are the features of a common peroneal neuropathy?

Answer 5

• Most common cause is entrapment at fibular head
• Hx of trauma, surgery or external compression, acute onset foot drop and sensory disturbance
• Tibialis anterior (ankle dosriflexion) and extensor hallicus longus (great toe extension) weakness

Question 6

What are the features of a femoral neuropathy?

Answer 6

• Most common cause is haemorrhage/trauma
• Weakness of quadriceps, weakness of hip flexion and numbness in medial shin
• Quadriceps (knee extension), iliopsoas (hip flexion) and adductor magnus (hip adduction) weakness