Peripheral Nerve Lesions Flashcards
what are the roots of the brachial plexus?
C5-T1
what are the trunks of the brachial plexus?
upper, (C5&6) middle (C7) and lower (C8&T1)
what trunks form the cords?
the upper and middle trunk form the lateral cord, the middle, upper and lower form the posterior cord, and the lower forms the medial cord
what branches do the cords create?
the lateral cord forms part of the musculoskeletal and median, the posterior forms part of the axillary and radial, and the medial forms the ulnar and the median
how can brachial plexus pathology come about?
blunt trauma, injuries at birth, penetrating trauma, disease
what are conditions associated with each type of brachial plexus injury?
upper BP: Erb’s Palsy
lower BP: Klumpke’s Palsy
How does Erb’s palsy come about?
there is excessive stretching of the neck during delivery causing damage to C5 and C6 nerve roots
what are the clinical presentations of Erb’s?
arms hang limply by side, unopposed medial rotation of shoulder, loss of elbow flexion and supination of forearm
what is the difference in how lower and upper brachial plexus injuries are created?
upper is usually a violent fall such as RCA, whereas lower is usually when you are trying to prevent a fall and the limb is pulled superiorly suddenly
where is the damage in Klumpke’s?
C8 and T1 - ulnar nerve and usually occurs in delivery when the upper limb is pulled excessively
what does the ulnar nerve innervate?
nothing in arm only FCU and medial half of FDP in forearm
what nerve innervates the hypothenar eminence, AP, interossei, and medial 2 lumbricals?
ulnar nerve
what is the clinical presentation of Klumpke’s?
paralysis of majority of intrinsic muscles of hand, imbalance between function in intrinsic and extrinsic muscles leading to claw hand and may be associated with Horner’s
features of Horner’s syndrome?
ptosis, miosis, anhidrosis, vasodilation
how many bones are in the upper limb?
19 bones, 17 joints and 19 muscles
