PNI and REHABILITATION Flashcards
motor [efferent] fibers
they provide voluntary muscle function by transmitting impulses from CNS to skeletal muscle
Sensory [afferent] fibers
provide transmission of sensory impulses from the environment to the CNS
Autonomic [efferent] fibers
controls trophic functions
types of damages
Wallerian degeneration
axonal degeneration
segmental demyelination
Wallerian degeneration
due to nerve axon damage and disruption of its integrity
can regenerate if nerve sheath is preserved
axonal degeneration
retrograde damage to cell body or axon
can be reversed if no deteriorating of axon integrity
segmental demyelination
myelinated fibers are damaged by surrounding schwan cells and/ or myeline sheath without damage to peripheral nerve axon
-complete reversal when the cause is removed
Seddon classification
neuropraxia
axonotmesis
neurotmesis
Neuropraxia
non degenerative
due to pressure
schwan membrane and axon are intact
partial loss of sensation
Axonotmesis
axon distraction
intact schwan membrane
degenerative lesion
motor and sensory impairment
neurotmesis
both nerve and schwan cell are devastated
very weak regeneration
there may remain scar tissue
degeneration
retrograde degeneration occurs when nerve injured
occurs within 14-21 days
neural mechanisms of regeneration
collateral reinnervation
axonal regeneration
reorganization of nervous system
lesion of cervical plexus
it innervates deep muscles of the neck
phrenic nerve lesion are common
unilateral lesion=paresis of hemidiaphragm
bilateral= dyspnea
lesion of brachial plexus
C5-T1
causes of brachial plexus lesion
tumor
accidents
trauma
obstetric
radiation
obstetric brachial plexus symptoms and risk factors
loss of strength
reflex changes
atrophy
loss of sensation
high birth weight
birth related
Erb’s palsy
occurs in brachial plexus lesion at level C5-6
it has waiters tip hand classical sign
klumpkle
lower brachial lesion C8-T1
claw hand and Horne’s syndrome
N. Thoracicus longus
injuries due to continuous pressure
S.A paralysis
Scapula Lata can be seen