Brachial Plexus Injuries Flashcards
What is an avulsion injury?
The nerve root is torn off the spinal cord at its origin
What is neurapraxia?
The nerve is stretched and damaged but not torn
What is a nerve rupture?
The nerve is torn at a point along its length
What is axonotmesis?
The nerve is partially severed
The axon and myelin sheath are torn but the surrounding epineurium, perineurium, and connective tissue are preserved
What is a post traumatic neuroma?
A growth of scar tissue at the site of previous nerve injury that leads to compression of the nerve
What is the injury mechanism that results in Erb’s palsy?
A traction injury due to excessive lateral neck flexion to the contralateral side or excessive shoulder depression causing violent stretching (+/- tearing) of the upper portion of the brachial plexus
What could cause Erb’s palsy?
Falls onto neck/shoulder
Motorcycling accidents
Direct trauma (clavicle fracture, gun shot wound, stab injury)
Attempts to reduce a shoulder dislocation
Traction injury during difficult/obstructed labour (breech with arms above head, shoulder dystopia + emergency forceps)
Excessive traction on the arm e.g. in sports
Where would a patient with Erb’s palsy experience loss of sensation?
The skin over the ‘sergeants patch’, lateral arm, and lateral forearm
In what muscles would you see wasting in a patient with Erb’s palsy?
The deltoid, supraspinatus and the anterior compartment of the arm
Which movements are preserved in patients with Erb’s palsy?
Wrist flexion and extension, and finger movements
Which movements are lost in a patient with Erb’s palsy?
Shoulder abduction
External rotation
Elbow flexion
Wrist supination
Which arm position do patients with Erb’s palsy typically present with?
Waiters tip
Limb adducted , internally rotated shoulder, extended elbow and pronated wrist
What reflex is absent in a patient with Erb’s palsy?
The bicep reflex is absent
What is the location an Erb’s palsy injury?
The superior trunk of the brachial plexus
That affects the suprascapular nerve, the nerve to subclavius, the musculocutaneous nerve and the auxiliary nerve
Is Erb’s palsy an upper brachial plexus injury?
Yes Erb’s palsy is an upper brachial plexus injury (injury to the superior trunk)
Is Klumpke’s palsy an upper brachial plexus injury?
No Klumpke’s palsy is a lower brachial plexus injury
What is the mechanism of injury that leads to Klumpke’s palsy?
A traction injury due to excessive force placed on an abducted shoulder resulting in violent stretching (+/- tearing) of the lower portion of the brachial plexus
What is the site of injury in the brachial plexus that results in Klumpke’s palsy?
The inferior frank of the brachial plexus
Affecting the median and ulnar nerves
Which is the rarest brachial plexus syndrome?
Klumpke’s palsy
What sensation is lost in a patient with Klumpke’s palsy?
Loas of skin sensation in the median and ulnar distributions of the hand and in the medial forearm and arm
What sensation is preserved in patients with Klumpke’s palsy?
Sensory supply to the lateral dorsum of the hand
What muscles would show wastage in patient with Klumpke’s palsy?
The muscles of the hand
What movements would be lost in a patient with Klumpke’s palsy?
Loss of movement in the hand, loss of wrist flexion
Which position would a patient with Klumpke’s palsy typically present with?
Claw hand
What movement is usually preserved in a patient with Klumpke’s palsy?
Shoulder movement is usually preserved
What injuries could lead to Klumpke’s palsy?
A falling person grabbing onto something
Motor biking accident
Direct trauma (GSW, stab injury, clavicle fracture)
Difficult childbirth = arm prevention requiring force on the arm to deliver the baby
Compression of the lower plexus by a ,ass in the root of the neck e,g. Lymphoma or lung cancer
What could cause total/complete brachial plexus injury?
Severe traction injuries sustained in difficult childbirth
High speed road traffic accidents
What is the clinical presentation of someone with a total complete brachial plexus injury?
Totally limp, dangling, atrophied, numb upper arm, with associated Horners syndrome
What is the most common cause of Klumpke’s palsy?
Difficult childbirth
What is the site of injury for Horners syndrome?
The T1 nerve root
What could cause Horner’s syndrome?
Cerebral pathology
Traction injury
Direct trauma
Extrinsic compression
How does Hornerks syndrome present?
Ipsilateral partial ptsosis (drooping eyelid)
Enophthalmos (eye appears sunken)
Anhidrosis (loss of sweating on one side of the face)
Constricted pupil
Loss of sympathetic nerve supply of the face and neck
In Horners syndrome caused by nerve root compression what symptoms are present?
Hand/arm pain
Wasting of the intrinsic muscles of the hand
In Horner’s syndrome caused by traction injuries what other palsy is associated with it?
Klumpke’s palsy
What is the mechanism of injury that results in Horners syndrome?
Any injury to the T1 root that is associated with loss of sympathetic function
Where does brachial neuritis/plexitis occur?
Any part of the brachial plexus
What is the mechanism of brachial neuritis?
Inflammatory reaction against the nerves of the brachial plexus
What can cause brachial neuritis
Brachial neuritis can be triggered by:
Bacterial, viral, parasitic infections
Trauma
Childbirth
Recent surgery
Recent radiotherapy
Systemic inflammation disorders e.g. lupus
Can be idiopathic
Can be part of a polyneuropathy
What are the clinical feature of brachial neuritis?
Sudden onset of excruciating shoulder and arm pain
Development of paralysis and atrophy of affected muscles
How long after onset do patients tend to present for brachial neuritis?
Patients present acutely due to the pain
In what position do patients with brachial neuritis tend to present?
Supporting arm in adducted, internally rotated position
What is thoracic outlet syndrome?
Compression of the neurovascular structures at the level of the thoracic outlet
What part of the brachial plexus does thoracic outlet syndrome affect?
The trunks of the brachial plexus
Typically the inferior trunk but can be any and all of the trunks
What borders the thoracic outlet?
The anterior scalene muscle, middle scalene muscle, clavicle and first rib
What can cause thoracic outlet syndrome?
Trauma - whiplash
Repetitive strain/sports injuries
Underlying malignancy - lymphoma, lung cancer
Malunion of a clavicular fracture
Cervical rib
Musculoskeletal abnormality
Congenital fibrous tissue band
What are the neurological features of thoracic outlet syndrome?
Wasting of intrinsic muscles of the hand
Reduced grip strength
Numbness of paraesthesia
What are the vascular feature of thoracic outlet syndrome?
Subclavian artery compression leads to:
Aching, painful claudication of the arm
Pallor
Extreme cold of the arm
Ischaemia with ulceration and gangrene (in extreme cases)
Subclavian vein compression leads to:
Diffuse arm pain and swelling
Venous distension
Cyanosis
Subclavian vein compression as a result of thoracic outlet syndrome leads to:
Diffuse arm pain and swelling
Venous distension
Cyanosis
Subclavian artery compression as a result of thoracic outlet syndrome leads to:
Aching, painful claudication of the arm
Pallor
Extreme cold of the arm
Ischaemia with ulceration and gangrene (in extreme cases)
