Foot drop

Question 1

What are the possible causes of foot drop?

Answer 1

Common peroneal nerve lesion/palsy - most common cause
L5 radiculopathy
Sciatic nerve lesion
Superficial or deep peroneal nerve lesion
Stroke

Question 2

What can cause CPN palsy?

Answer 2

Prolonged positions that compress CPN at neck of fibula e.g. leg crossing, squatting, kneeling

Question 3

What are the features of CPN palsy?

Answer 3

Foot drop
Decreased sensation/numbness/tingling on lateral aspect of shin or top of the foot
Weakness of ankles – weakness in dorsiflexion and eversion of ankle
Slapping gait

Ankle reflex PRESENT as CPN does not mediate this reflex, rather S1 nerve does

Question 4

What are features of L5 radiculopathy?

Answer 4

Weakness in hip abduction
Weakness in both eversion and inversion of foot
Sciatica

Ankle reflex LOST if cause of radiculopathy is slipped disc as it almost always involves S1 root

Question 5

What investigations are carried out in CPN palsy?

Answer 5

Nerve conduction study:
Most are demyelinating lesions (full recovery might be expected usually within weeks.

EMG:
Used for more severe compressive lesions that have axon loss. EMG will show denervation if axonal lesions present. Recovery of axonal loss problems takes longer to recover and may be incomplete.

Question 6

What causes a wrist drop?

Answer 6

Compression of radial nerve

Question 7

What are the features of a wrist drop?

Answer 7

Wrist and fingers can’t extend at MCP joint

Question 8

What investigation can be carried out in wrist drop?

Answer 8

Nerve conduction study

Question 9

What is the management for wrist drop?

Answer 9

Splint