Ulnar Neuropathy at the Elbow and Wrist

Question 1

Ulnar neuropathy at the elbow is the ___ most common focal neuropathy of the UE.

Answer 1

2nd

median nerve is most common (carpal tunnel)

Question 2

The most common site of focal ulnar entrapment or compression is at the ____, followed by the ____.

Answer 2

elbow

wrist

Question 3

What is the etiology of ulnar nerve lesions at the elbow?

Answer 3

• acute trauma (distal humeral fracture, nerve lacerations, perioperative injury)
• nerve compression
• traction
• friction from leaning on the elbow or from prolonged elbow flexion
• subluxation of the ulnar nerve laterally over the medial epicondyle

Question 4

What are some intrinsic causes of ulnar neuropathy at the elbow?

Answer 4

• osteophytes
• arthritis
• synovitis
• anomalous muscles or fibrous bands
• ganglia
• other mass lesions

Question 5

What are the 2 branches off of the distal trunk of the ulnar nerve that can be injured around the wrist?

Answer 5

• superficial sensory branch

- deep motor branch

Question 6

What are the extrinsic causes of ulnar neuropathy at the wrist?

Answer 6

• bone fractures (eg, hook of hamate)
• lacerations
• direct, often repetitive trauma, such as repetitive use of tools in the workplace or propulsion of a manual wheelchair

Question 7

_____ palsy is common in bicyclists

Answer 7

Handlebar

Question 8

What are the intrinsic causes of ulnar neuropathy at the wrist?

Answer 8

• ganglia arising from the wrist joint

- intraneural ganglia

Question 9

Many cases of ulnar neuropathy are ______.

Answer 9

idiopathic

Question 10

Localization of entrapment is dependent upon what?

Answer 10

• the clinical scenario
• the presence of proximal pain or a mass pain
• the involvement of other nerves (median and radial)

Question 11

What are 2 places distal to the elbow in which the ulnar nerve can become entrapped?

Answer 11

• within the body of flexor carpi ulnaris muscle

- where it exits through the deep flexor-pronator aponeurosis

Question 12

The annual incidence of ulnar neuropathy is ___ per 100,000 people

Answer 12

24.7

Question 13

The prevalence of ulnar neuropathy in ____ is double that in _____.

Answer 13

men

women

Question 14

Ulnar neuropathy is positively associated with what?

Answer 14

smoking

Question 15

Are gender, body mass index, alcohol consumption, elbow trauma, diabetes, and hypertension risk factors for ulnar neuropathy?

Answer 15

no

Question 16

What are the clinical features of ulnar neuropathy at the elbow?

Answer 16

• numbness and tingling in the fourth and fifth digits
• medial elbow and forearm pain
• nocturnal numbness and paresthesia
• worsening of symptoms with elbow and/or repeated wrist flexion

Question 17

What are the clinical features of ulnar neuropathy at the wrist?

Answer 17

• hand weakness and atrophy
• loss of dexterity
• variable sensory involvement

Question 18

What characteristic of ulnar neuropathy is more pronounced with lesions at the wrist than at the elbow?

Answer 18

clawing of digits 4 and 5

Question 19

Injury to the terminal branches of the ulnar nerve at the wrist can occur at 4 sites. What are they?

Answer 19

• the main trunk of the nerve proximal to or within Guyon’s canal
• the deep terminal motor branch of the ulnar nerve proximal to the branches supplying the hypothenar muscles
• the deep motor branch distal to the hypothenar muscles
• the superficial terminal branch supplying the superficial sensory branches

Question 20

What are 5 provocative measures for ulnar neuropathy?

Answer 20

• Tinel’s test
• elbow flexion
• pressure
• combined elbow flexion with pressure
• palpation

Question 21

How is Tinel’s test performed?

Answer 21

Firm percussion over the ulnar nerve in the ulnar groove and a bit further distally over the cubital tunnel

Question 22

What 2 imaging techniques are useful in helping diagnose ulnar neuropathy?

Answer 22

Ultrasound and MRI

Question 23

What are 2 differential diagnoses for UNE and UNW?

Answer 23

Proximal lesions of the C8 or T1 roots and the lower trunk/medial cord of the brachial plexus

Question 24

When is conservative treatment suggested over surgery for ulnar neuropathy?

Answer 24

For patients with mild to moderate UNE or UNW, characterized by intermittent or persistent sensory loss and weakness without wasting, and no causative structural lesion. Also in those who have moderate to severe but stable ulnar neuropathy of less than six months duration.

Question 25

To prevent excessive or prolonged elbow flexion, splints that limit flexion to __ to __ degrees can be used at night

Answer 25

45-90

Question 26

What are the 2 main categories of operation performed for UNE?

Answer 26

• in situ decompression of the ulnar nerve

- ulnar transposition

Question 27

What surgery approach is recommended for UNW?

Answer 27

decompression of the ulnar tunnel (Guyon’s canal)