Brachial Plexus Injuries

Question 1

dystocia

Answer 1

difficult labor or birth

Question 2

shoulder dystocia

Answer 2

• baby’s head becomes lodged behind the mother’s pubic bone
• body does not follow the head easily outside of the mother vaginal canal during delivery.
• The majority of brachial plexus injuries follow a shoulder dystocia during delivery.
• During delivery, force is exerted to pull the baby from the canal. One side of the baby’s neck is stretched, this can damage the brachial plexus nerves.

Question 3

obstetric brachial plexus injuries

Answer 3

Transient or permanent injury to the brachial plexus resulting from a difficult birth; a mechanical injury commonly caused by traction to the baby’s head and neck during delivery

Question 4

incidence and risk factors

Answer 4

Incidence:

• ~1/500 births
• Most commonly caused by shoulder dystocia

Risk Factors:

• Fetal Macrosomia - Large baby (gestational diabetes or obese mothers)
• Breech presentation
• Prolonged labor and use of extraction techniques (forceps/vacuum extraction – accounts for 30% of all Erb’s Palsy
• Mother’s pelvis is too small for vaginal delivery

Question 5

injury at root level C4

Answer 5

phrenic nerve causing hemi-diaphragmic paralysis

Question 6

injury at root level C5

Answer 6

Dorsal scapular nerve: levator scapula and rhomboids

Question 7

injury at root level C7

Answer 7

C7 – Long thoracic nerve: serratus anterior

Question 8

injury at root level T1

Answer 8

T1 – sympathetic chain causing ptosis (Horner’s sign)

Question 9

grade 3 rupture

Answer 9

the nerve is torn, but not the spinal attachment

Question 10

grade 3 neuroma injuries

Answer 10

The nerve has tried to heal itself, but scar tissue has grown over the injury. The scar tissue that forms puts pressure on the injured nerve and preventing the nerve from conducting signals to the muscles.

Question 11

grade 2

Answer 11

Axonal Disruption – sheath remains intact, but axons inside sheath disrupted. Axons heal/regenerate at a rate of 1in/month

Question 12

grade 1 stretch injuries (neurapraxia)

Answer 12

*most frequent

the nerve is damaged, but not torn. Normally, these injuries heal on their own, usually within 3 months

Question 13

upper/middle/lower trunk muscles

Answer 13

upper - shoulder girdle, biceps
middle - triceps, wrist extensors
lower - small mx of hand

Question 14

Narakas classification - group I

Answer 14

C5,6 paralysis of shoulder and biceps (90% recover fully by 6 months)

Question 15

Narakas classification - group II

Answer 15

C5,6,7 paralysis of shoulder, biceps, and wrist extensors (steady improvement, some contractures on limb)

• “waiter’s tip” posture
• 60% recover, rarely fully

Question 16

Narakas classification - group III

Answer 16

paralysis of entire limb (slow, partial recovery and limited function in limb, may need surgery)
- no Horner’s sign

Question 17

Narakas classification - group IV

Answer 17

paralysis of entire limb with temporary Horner’s sign (poor shoulder, elbow, and forearm recovery, surgery)
*needs surgery

Question 18

Narakas classification - group V

Answer 18

paralysis of entire limb with persistent Horner’s sign and poor recovery. (poor shoulder, elbow, and forearm recovery, surgery)

Question 19

Erb’s palsy

Answer 19

the MOST common type, best prognosis. Damage to the upper trunk of the plexus at the junction of the nerve roots C5 to C6. Typically present with arm straight and wrist bent (“Waiter’s Tip”)

Question 20

motor deficits and areas spared of erb’s palsy

Answer 20

Motor deficits:

• Inability to abduct the shoulder, externally rotate the shoulder, flex the elbow, supinate the forearm
• Weak wrist extension
• DTRs are absent

Areas Spared:

• Full hand movement
• Normal grasp and digit movement

Question 21

Klumpke’s palsy

Answer 21

the LEAST common type, often less spontaneous recovery. (Usually following breech delivery with head above arm) Damage to the lower trunks of the plexus at the junction of nerve roots C8-T1.

Question 22

motor deficits and areas spared in Klumpke’s palsy

Answer 22

Motor deficits:

• Inability to flex the wrist
• Finger extension
• Wrist flexors
• Inability to grasp
• Hand intrinsics
• Finger flexors
• If the sympathetic fibers of T1 are involved, there may be an ipsilateral ptosis and miosis (Horner’s Syndrome)

Areas Spared:

• Full elbow movement
• Full forearm movement
• Full shoulder movement

Question 23

Erb-Duchenne-Klumpke’s palsy

Answer 23

Damage to the upper and lower trunks of the plexus, nerve roots C5-T1

Question 24

medical treatment for brachial plexus injury

Answer 24

• complete neurologic exam
• spontaneous healing could occur
• surgical options: neurolysis, neuroma excision, nerve grafting, muscle and bone surgeries

Question 25

what UE joint will be most affected over time

Answer 25

glenohumeral!!!!

Question 26

therapy after surgery

Answer 26

Limb will be immobilized. Physician will order re-initiation of therapy services. This could begin 1-2 times a week for 2-6 months with focus on functional electrical stimulation and strengthening of re-innervated muscles.

Question 27

OT eval and brachial plexus assessments

Answer 27

AROM and PROM: active movement scale, modified mallet classification

sensation, hand movement, developmental milestones, ADLs

Question 28

acute care (infants following birth)

Answer 28

• protect affected arm to help with spontaneous healing
• provide gentle PROM to maintain flexibility in mx and AROM to build strength
• provide sensory experiences to prevent baby from neglecting arm

Question 29

treatment considerations

Answer 29

• prevent musculoskeletal deformities
• promotion of function
• prevention of developmental problems with motor planning

daily home program, splinting, kinesiotape, musculoskeletal alignment
*prevent GLH joint deformity