peripheral nerves Flashcards
Name the 4 major functions of Schwann cells
1) phagocytosis
2) myelination
3) NMJ
4) basal lamina path for regeneration
what structure lies within endoneurium
nerve fiber (axon + schwann cell)
what structure lies within perineurium
a fascicle (a bunch of nerve fibers)
what structure lies with epineurium
a peripheral nerve
which spinal nerves exit the spinal cord rostral to their corresponding vertebral bodies
C1-C7
C8 exits below C7 and above T1
what is central chromatolysis
fragmentation and dispersal of Nissl bodies and displacement of the nucleus (eccentric nucleus)
seen in Wallerian Degeneration
what is a pseudoneuroma
swirls of regenerating axons trapped in scar tissue
occurs when axons don’t make contact with Schwann cells of distal stump
what are the findings of a radiculopathy
1) characteristic shooting pain
2) dermatomal sensory loss
3) myotomal weakness
what are the etiologies of radiculopathy
herneated nucleus pulposus bony spur tumor abscesses hematoma
what are the 2 most common radiculopathies
C7, S1
What are the associated pain, sensory loss, motor loss and reflex loss with a C7 radiculopathy
Pain: neck, lateral arm, forearm, digits 2-3
Sensory: digit 3
Motor: triceps, radial flexors and extensors
Reflex: triceps
What are the associated pain, sensory loss, motor loss and reflex loss with an S1 radiculopathy
Pain: posterior thigh and calf, sole of foot
Sensory: posterior calf, lateral foot
Motor: plantar flexors and invertors
Reflex: ankle
describe and give lesion location for Erb’s Palsy
Location: C5, C6
waiter’s tip shoulder problem
describe and give the lesion location for Klumpke’s Palsy
Location: C8, T1
claw hand
describe the pain, weakness etiology and treatment of idiopathic brachial neuropathy
also called Parsonage-Turner syndrome Pain: shoulder/axilla Weakness: shoulder girdle, hands Etiology: vaccinations, inflammation, surgical positioning Treatment: steroids, physical therapy
describe diabetic amyotrophy
1) intense pain in thigh
2) ischemia to vasa nervosum
3) lumbosacral plexopathy
4) motor nerve problem with secondary muscle atrophy
5) unilateral, but other leg usually follows
6) absent patellar reflex
what are the 5 major upper compressive mononeuropathy
1) axillary
2) median
3) ulnar
4) radial
5) musculocutaneous
describe axillary neuropathy, including motor and sensory loss
deltoid motor and sensory loss, with deltoid atrophy
describe musculocutaneous neuropathy, including motor and sensory loss
Motor: biceps
Sensory: lateral forearm
hypertrophy most common cause of compression
describe median neuropathy, including motor and sensory loss
carpal tunnel
Motor: LOAF muscles
Sensory: first 3 + lateral 4th
tinnel and phalens sign
describe ulnar neuropathy, including motor and sensory loss
Motor: hypothenar and interossei muscles, flexor carpi ulnaris
Sensory: 5 and medial 4
describe radial neuropathy, including motor and sensory loss
Motor: wrist drop
Sensory: dorsum of hand over 1st web space
saturday night palsy
compression at spiral groove of humerus
describe lateral femoral cutaneous neuropathy, including motor and sensory loss
meralgia paresthetica Motor: NONE Sensory: anterolateral thigh pain and parasthesias constriction at inguinal ligament (fat or tight clothes)
describe femoral neuropathy, including motor and sensory loss
Motor: Psoas, quadriceps femoris
Sensory:anteromedial thigh and leg
etiology: tumor, hematoma, abscess, trauma
obturator neuropathy
Motor: hip adductors
Sensory: medial thigh
etiology: prolonged labor
describe sciatic neuropathy, including motor and sensory loss
Motor: hamstrings all muscles of leg and foot
Sensory: poster lateral leg and entire foot
etiology: hip replacement, injections, tumor
describe paroneal neuropathy, including motor and sensory loss
motor: ankle dorsiflexion and eversion
sensory: lateral leg
etiology: weight loss and leg crossing
foot drop
describe tibial neuropathy, including motor and sensory loss
Tarsal tunnel syndrome
Motor: intrinsic foot muscles
Sensory: sole of foot
