Brachial Plexus

Question 1

Most common traumatic brachial plexus injuries are:

Answer 1

supraclavicular injuries involving complete involvement of all roots (80%)

Question 2

Speed of nerve regeneration is:

Answer 2

1mm per day.

Plexus recovery can take up to 3 years

Question 3

Worst prognosis is with these injuries:

Answer 3

root avulsions (pre-ganglionic)
- not reparable

Question 4

Best prognosis with these injuries

Answer 4

Infraclavicular plexus injuries

Upper plexus injuries (preserves hand function)

Question 5

Signs of Pre-ganglionic Injury

Answer 5

• Horner’s syndrome
• Medial scapular winging (Long thoracic n)
• flail arm
• normal histamine test
• elevated hemidiaphragm (phrenic)
• Rhomboid paralysis (dorsal scapular n)
• Cuff weakness (suprascapular n)
• Latissimus weakness
• EMG = no innervation to cervical paraspinals

Question 6

Signs of post-ganglionic injury:

Answer 6

EMG with maintained innervation to cervical paraspinals

- abnormal histamine test… redness and wheal positive, NO FLARE

Question 7

Most common brachial plexus obstetrical palsy:

Answer 7

Erb’s

• C5, C6
• has best prognosis

Question 8

Causes of a Klumpke Palsy

Answer 8

C7-8 root involvement

• hyperabduction injury
• cervical rib
• lung mets in lower deep cervical lymph nodes

Question 9

Clinical features of a Klumpke:

Answer 9

• claw hand
• unopposed wrist extensors
• loss of hand intrinsics therefore IP flexion and MP hyperextension

Question 10

Essential muscles to check in brachial plexopathy:

Answer 10

serratus anterior

- rhomboids (if functioning, then likely a post-ganglioinc)

Question 11

Define: SNAPs

Answer 11

sensory nerve action potentials

• measured in NCS
• preserved in lesions proximal to the DRG. Therefore distinguishes between pre and post-ganglionic

Question 12

Best clinical sign of nerve regeneration?

Answer 12

advancing Tinel sign

Question 13

Indication for immediate surgical exploration?

Answer 13

sharp, penetrating trauma

• iatrogenic injuries
• open injuries
• progressive defects
• expanding hematoma or vascular injury

Question 14

IS direct nerve repair possible for plexus injuries?

Answer 14

typically not as these are avulsion injuries

Question 15

Nerve grafting plexus injuries:

Answer 15

• useful in traction injuries

- preferable to graft the upper and middle trunk

Question 16

Neurotization for plexus injuries:

Answer 16

• transfer a working but non-essential motor nerve

- use extra-plexal source of axons such as CN XI, intercostal nerves, contra-lateral C7, CN XII

Question 17

Oberlin Transfer:

Answer 17

ulnar nerve is used for upper trunk injury to gain biceps function

Question 18

Horner’s Syndrome

Answer 18

disruption of the sympathetic chain at C8 or T1 root level

- seen concomitantly with pre-ganglionic injuries at this level

Question 19

Phrenic Nerve

Answer 19

C3,4,5

Question 20

Neurotization to restore elbow flexion - what procedure?

Answer 20

ulnar nerve fascicle to biceps
AND
median nerve fascicle to the brachialis

Question 21

Best surgical management of late-presenting plexopathies? (liek 2 years out…)

Answer 21

free muscle transfers

- nerve transfers unlikely to be sufficient due to loss of neuromuscular endplates at that time frame

Question 22

Quadrilateral space syndrome

Answer 22

dominant shoulder in overhead throwing athlete

• axillary nerve compression
• atrophy of deltoid and teres minor

Question 23

Risks for obstetrical brachial plexopathy

Answer 23

• LGA
• multiparous
• dystocia
• forceps
• breech
• prolonged labor

Question 24

Upper extremity issues from obstetrical brachial plexopathy

Answer 24

• glenoid dysplasia, retroversion, humeral head flattening, posterior humeral head subluxation
• Elbow flexion contracture

Question 25

Poor prognosis for recovery of obstetical plexopathy?

Answer 25

• lack of biceps function by 3 months

- preganglionic injuries

Question 26

Narakas Classification

Answer 26

I: Erb’s
II: Intermediate (C5-7)
III: total palsy without Horner’s
IV: total palsy with Horner’s

Question 27

Elbow contracture of <40 degrees, treatment

Answer 27

serial extension splinting
casting if >40 deg
if recalcitrant to treatment, use surgery

Question 28

How do you influence the natural history of glenoid dysplasia in obstetrical brachial plexopathy?

Answer 28

• address GH internal rotation contracture wth latissimus and teres major transfer
• ifdone at young age, significant remodeling potential exists
• relative contraindications include severe dysplasia such as glenoid convexity or absence, humeral head flattening

Question 29

Waters Classification - significance

Answer 29

if Waters GH dysplasia types II or III, do latissimus/teres major transfer

if Waters IV or V, do humeral derotational osteotomy

Question 30

When do you do reconstruction for post-ganglionic injuries?

Answer 30

at 3-9 months of life, using neuroma excision and sural nerve grafting

Question 31

When do you reconstruct pre-ganglionic injuries?

Answer 31

at 3 months of life, using nerve transfers

Question 32

What’s the prognostic value of a Horner’s syndrome in context of brachial plexopathy?

Answer 32

poor prognosis.

<10% will regain function (al-Qattan 2000, Waters 1999)