Upper Limb Nerve Injuries Flashcards
Ziermann
The roots of the brachial plexus comes from which rami?
Ventral Rami C5-T1
The roots of the brachial plexus are located where?
Deep to the anterior scalene muscle (ASM)
Where do the ventral primary rami unite to for the 3 trunks?
at the lateral border of the ASM
The anterior division of the trunks supply what?
Anterior muscles and skin of the upper limb
The posterior division of the trunks supply what?
Posterior muscles and skin
When entering the axilla, the divisions pass deep to what?
The clavicle
Where does the brachial plexus end?
In the axilla as cords give rise to main nerve branches of the upper limb
Anterior medial arm/forearm cutaneous innervation
Medial cutaneous nerves of the medial cord
Anterior lateral forearm cutaneous innervation
Continuation of the musculocutaneous nerve, which is the lateral ante brachial cutaneous nerve
Posterior medial arm cutaneous innervation
Medial brachial cutaneous nerve
Posterior medial forearm cutaneous innervation
Medial antebrachial cutaneous (C8, T1)
Posterior lateral forearm cutaneous innervation
Continuation of the musculocutaneous nerve, which is the lateral ante brachial cutaneous nerve
Anterior lateral arm cutaneous innervation
Axillary near deltoid
Radial - under axillary innervation
Posterior lateral arm/forearm cutaneous innervation
Axillary near deltoid
Radial the rest of the way down
What is cutaneous innervation?
based on clinical findings in a living person
Dermatomes
Based on development
Surface of the skin is divided into specific areas (connective tissue, including dermis)
derived from somites
What is segmental innervation?
A dermatome is an area of skin in which sensory nerves derive from a single spinal nerve root
Avulsion
most sever type
Nerve is torn from spine (pull the root of the brachial plexus out the neck)
Rupture
nerve is torn but not at the spinal attachment (nerve stretched and ruptured in two parts
Neuroma
nerve has torn and healed but scar tissue puts pressure on injured nerve and prevents it from conduction signals to muscles
Neuropraxia
Stretched
Nerve has been damaged but not torn
Most common type of of brachial plexus injury
Most severe brachial plexus injuries are caused by which two events?
Car and motorcycle accidents
these can leave arm paralyzed, with loss of function and sensation
For avulsion and rupture injuries, can they be repaired?
there is no potential for recovery unless surgical reconnection is made in a timely manner
For neuroma and neuropraxia, can they be repaired?
potential for recovery varies
Most people with neurpraxia injuries recover spontaneously with a 90-100% return of function
Stingers/burners
Minor brachial plexus injuries
common causes: contact sports
Stinger -> compression or over-stretching of nerves
Root injury
lateral flexion of neck toward the side of symptoms
- foraminal narrowing (compression), especially in the presence of an underlying disc herniation or osteophyte
Plexus injury
neck and upper trunk vulnerable to direct blows or stretching from distraction of neck away from shoulder
What are the two nerve roots that are most commonly affected?
C5 and C6
Erb’s palsy
Paralysis of upper brachial plexus (C5, C6) > Upper trunk damaged
What are the most commonly involved nerves of Erb’s Palsy?
Suprascapular (C5-C6) - Paralysis of muscles
Musculocutaneous (C5-C7) - Paresis of muscles
Axillary (C5-C6) - Paralysis of muscles
If roots are damaged above the junction of C5 and C6 what results?
paralysis of rhomboids (dorsal scapular n.) and serratus anterior (long thoracic n, C5-C7) is added, producing weakness in retraction and protraction the scapula
What is the most common area for the upper brachial plexus to be damaged?
Upper trunk
What are the nerves that only contains C5 and C6 nerve fibers?
Axillary nerve
Lower subscapular
Upper subscapular
What is the characteristic sign of Erbs Palsy?
Waiters tip deformity
Arm - rotated medially (loss of lateral rotators of the shoulder- rotator cuff muscles)
Arm - hangs (lack of abduction - deltoid and supraspinatis
Forearm - extended and pronated (weakness of arm flexors and biceps; weak supinator - C5-C6 radial nerve)
What is Klumpke’s Palsy? and it’s symptoms?
Paralysis of the lower brachial plexus (C8, T1)
Symptoms: Claw hand, severe pain, loss sensation, dermatome numbness
What are the affected nerves in Klumpke’s Palsy?
medial pectoral nerve Medial brachial cutaneous Medial antebrachial cutaneous Ulnar n. (main nerve affected) Radial n. Median n.
What is claw hand?
Affected forearm tends to lie flat and the wrist and fibers are tightened
Hyperextension of the hand at the metacarpalphalangeal jointed flexion of the hand at the interphalangeal joint
What are the muscles paralyzed in Klumpke’s palsy?
Flexor carpi ulnaris
Medial half of flexor digitorium profundus
most intrinsic hand muscles (ulnar)
Pecotralis minor (medial pectoral nerve)
How do you test for Erb’s Palsy
Weakness in supinator
Radial nerve affected (C5-T1)
How do you test for Klumpke’s palsy?
check intrinsic hand muscles
Flexors of the wrist and fingers
Check lumbrical function
Looking to see if ulnar (C8,T1) and median nerve (C5-T1) is ok
