Class 2 Flashcards
Mononeuropathy
Single peripheral nerve affected
Commonly the result of trauma
Compression syndromes of peripheral nerves
Cause local conduction block, but no structural damage
Numbness, tingling, pain and weakness.
Trauma –> inflammation –> impaired nerve transmission
Polyneuropathy
Several peripheral nerves affected
Radiculoneuropathy
Involves nerve root as it emerges from spinal cord
Polyradiculitis
Involvement of several nerve roots
Inflammatory response to infection.
Cervical plexus
Formed by anterior rami of C1-4
Superficial/sensory branches of cervical plexus
Lesser occipital
Great auricular
Transverse cervical
Supraclavicular
Lesser occipital branch
Sensory/superficial branch of cervical plexus
Origin: C2
Innervates: skin of scalp (posterior and superior to ear)
Great Auricular branch
Sensory/superficial branch of cervical plexus
Origin: C2-3
Innervates: skin anterior, inferior and over ear; skin over parotid glands
Transverse cervical branch
Sensory/superficial branch of cervical plexus
Origin: C2-3
Innervates: skin over anterior neck
Supraclavicular branch
Sensory/superficial branch of cervical plexus
Origin: c3-4
Innervates: skin over superior chest and shoulders
Deep (motor) branches of cervical plexus
Ansa cervicalis superior root
Ansa cervicalis inferior root
Phrenic
Segmental branches
Ansa cervicalis superior root
Deep branch of cervical plexus
Origin: C1
Innervates: infrahyoid and geniohyoid
- loops with ACIR
Ansa cervicalis inferior root
Deep branch of cervical plexus
Origin: C2-3
Innervates: infrahyoid
- loops with ACSR
Phrenic branch
Deep branch of cervical plexus
Origin: C3-5
Innervations: diaphragm
Segmental branches
Deep branches of cervical plexus
Origins: C1-5
Innervate: mm of neck, levator Scap, scalenes.
Severing spinal cord over what level causes respiratory arrest?
C3
Brachial plexus
C5-T1
Passes above R1, behind clavicle and enters axilla.
Supplies shoulders and arms
Branches of the brachial plexus
Dorsal scapular Long thoracic Nerve to subclavius Suprascapular Musculocutaneous Lateral pectoral Upper subscapular Thoracodorsal Lower subscapular Axillary Median Radial Medial pectoral Medial cutaneous of arm Medial cutaneous of forearm Ulnar
Roots
Anterior rami of spinal nerves
Combine to form trunks
Trunks
Roots combine to form trunks.
In brachial plexus: superior, middle and inferior
Trunks divide into divisions
Divisions
What trunks divide into posterior to clavicle.
Unite in axilla to form cords
Cords
In axilla, what divisions untie to form.
Lateral, medial and posterior
Lead to branches.
Dorsal scapular nerve
C5
Levator scap
Rhomboids Major and minor
Long thoracic
C5-7
Serratus anterior
Nerve to subclavius
C5-6
Subclavius
Suprascapular
C5-6
Supraspinatus
Infraspinatus
Musculocutaneous
C5-7
Coracobrachialis
Brachialis
Biceps brachii
Lateral pectoral
C5-7
Pec major
Upper subscapular
C5-6
Subscapularis
Thoracodorsal
C6-8
Lats
Lower subscapular
C5-6
Subscapularis
Teres major
Axillary
C5-6
Deltoids
Teres minor
Skin (delt, sup/post arm)
Median
C5-T1
Forearm flexor (except FCU)
Some hand muscles
Skin of lat palmar hand and fingers
Radial
C5-T1
Posterior arm
Skin of lat dorsal hand and post arm
Medial pectoral
C8-T1
Pec major and minor
Medial cutaneous nerve of arm
C8-T1
Skin of medial/posterior distal arm
Medial cutaneous nerve of forearm
C8-T1
Skin of medial/posterior forearm
Ulnar
C8-T1
FCU
FDP
Most hand muscles
Skin of medial hand and digit 5, medial 4
C5
Dorsal scapular
C5-6
Nerve to subclavius Suprascapular Upper subscapular Lower subscapular Axillary
C5-7
Long thoracic
Musculocutaneous
Lateral pectoral
C5-T1
Median
Radial
C6-8
Thoracodorsal
C8-T1
Median pectoral
Medial cutaneous nerve of the arm
Medi cutaneous nerve of the forearm
Ulnar
Erb-Duchenne palsy
Injury to superior root of brachial plexus (C5-6)
Traction injury
Distinguished by Waiters Tip.
No sensation over lateral arm
Klumpke’s paralysis
Traction injury of lower brachial plexus
Medial and ulnar lesions
Claw hand
Sensory loss affecting C8-T1 dermatomes
Horner’s syndrome
Can result from Erb’s or Klumpke’s
Characterized by miosis, ptosis, anhydrosis, enophthalmos
Miosis
Constriction of pupil
Ptosis
Drooping eyelid
Anhydrosis
Loss of sweating in face and neck
Enophthalmos
Recession of eyeball into orbit
Path of radial nerve
Posterior axillary wall, between long and medial heads of triceps
Spiral groove of humerus
Winds to lateral humerus, then anterior humerus btwn brachialis and brachioradialis
Branches just before supinator into posterior motor branch and superficial sensory branch.
Motor branch travels through supinator.
Sx’s of radial nerve lesions
Altered sensation in posterior arm and hand (digits 1-3, half of 4)
If injury before elbow, both motor and sensory symptoms.
Wrist drop
Crutch palsy
Radial nerve lesion at axilla
Saturday night palsy
Radial nerve lesion at spiral groove at humerus.
Posterior interosseus syndrome
Radial nerve lesion
Compression at arcade of Frohse (between heads of supinator)
Wrist drop
Cheiralgia paresthetica
Radial nerve lesion as it passes under brachioradialis tendon
Sensory
Pain at dorsum of wrist, thumb, web space
“Handcuff syndrome”
Path of median nerve
Medial humerus to cubital fossa (beside coracobrachialis)
Between heads of pronator teres, then deep
Can be compressed by FCR and FDS
Enters carpal tunnel.
Symptoms of median nerve lesions
Ape hand Oath hand (only 4&5 can flex)
Difficulty grasping, pronating, flexing PIPs or DIPs 2-3.
Weak wrist flexion, thumb movements
Ligament of Struthers
Unusual. Extra ligament running from spur on humerus to medial epicondyle.
12-15%
Can compress median nerve. Motor and sensory loss.
Pronator teres syndrome
Median nerve compresses at proximal attachment of pronator teres.
Aching in anterior forearm, numbness in thumb and index finger.
Some thenar weakness
Anterior interosseus syndrome
Median nerve lesion
Compression between heads of pronator teres.
Pain and motor loss at FPL, lateral half of FDP, pronator quadratic
Paralysis of digits 1-2. Can’t make OK.
Carpal tunnel syndrome
Most common entrapment condition in arm.
Numbness and tingling in 1-3, half of 4
Distinguished by night waking due to SX’s.
Compression in tunnel due to decreases tunnel size or increase size of contents.
Structures that pass through carpal tunnel
flexor digitorum superficialis (4 tendons)
Flexor digitorum profundus (4 tendons)
Flexor pollicis longus (1 tendon)
Median nerve
