Mononeuropathies

Question 1

Which muscles are supplied by the median nerve?

Answer 1

LOAF muscles:
L - Lateral lumbricals 
O - Opponens pollicis
A - Abductor pollicis brevis
F - Flexor pollicis brevis

Question 2

Which spinal nerves does the median nerve arise from?

Answer 2

C6-T1

Question 3

Which is the most common mononeuropathy?

Answer 3

Carpal tunnel syndrome

Question 4

What is this a presentation of?
Aching pain in hand and arm (especially at night). Paraesthesia in thumb, index, and middle fingers, relieved by dangling hand over edge of bed and shaking it. Some sensory loss and late motor involvement.

Answer 4

Carpal tunnel syndrome

Question 5

What causes Carpal tunnel syndrome?

Answer 5

Anything compressing the flexor retinaculum:

1. Hypothyroidism, acromegaly
2. Myeloma, local tumours
3. Rheumatoid arthritis, sarcoidosis, pregnancy

Question 6

What is the treatment for Carpal tunnel syndrome?

Answer 6

Splinting, local steroid injections, decompression surgery.

Question 7

What is this a presentation of?
Weakness/wasting of ulnar wrist flexors, interossei (can’t cross fingers), claw hand (medial lumbricals), hypothenar eminence wasting, sensory loss.

Answer 7

Ulnar nerve palsy

Question 8

Which spinal nerves does the ulnar nerve arise from?

Answer 8

C7-T1

Question 9

Which muscles are innervated by the radial nerve?

Answer 9

BEAST muscles:
B - Brachioradialis
E - Extensors
A - Abductor pollicis longus
S - Supinator
T - Triceps

Question 10

What is this a presentation of?

Wrist drop, sensory loss over anatomical snuffbox.

Answer 10

Radial nerve palsy

Question 11

Which spinal nerves does the radial nerve arise from?

Answer 11

C5-T1

Question 12

What is this a presentation of?

Pain/paraesthesia and weakness in the affected arm in a variable distribution.

Answer 12

Brachial plexus

Question 13

What are the causes of a brachial plexus palsy?

Answer 13

Trauma, radiotherapy for breast cancer, cervical rib.

Question 14

What is this a presentation of?

Mononeuropathy causing orthopnoea and a raised hemidiaphragm on chest x-ray.

Answer 14

Phrenic nerve palsy

Question 15

Which spinal nerves does the phrenic nerve arise from?

Answer 15

C3-C5

Question 16

What is this a presentation of?

Anterolateral burning thigh pain from entrapment under the inguinal ligament.

Answer 16

Lateral cutaneous nerve of the thigh entrapment

Question 17

Which spinal nerves does the lateral cutaneous nerve of the thigh arise from?

Answer 17

L2-L3

Question 18

What is this a presentation of?
Lesions affect the hamstrings and all muscles below the knee (foot drop) with loss of sensation below the knee laterally.

Answer 18

Sciatic nerve entrapment (pelvic tumour/fracture)

Question 19

Which spinal nerves does the sciatic nerve arise from?

Answer 19

L4-S3

Question 20

What is this a presentation of?

Foot drop, weak ankle dorsiflexion/eversion, sensory loss over dorsal foot.

Answer 20

Common peroneal nerve palsy

Question 21

Which spinal nerves does the common peroneal nerve arise from?

Answer 21

L4-S1

Question 22

What is this a presentation of?

Loss of plantarflexion, foot inversion, sensory loss on the sole of the foot.

Answer 22

Tibial nerve palsy

Question 23

Which spinal nerves does the tibial nerve arise from?

Answer 23

L4-S3

Question 24

What causes should you consider in multiple mononeuropathies?

Answer 24

Systemic causes - vasculitis, diabetes mellitus, rheumatoid arthritis, SLE