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Path PNS
KYCOM Block 13
88
Pathology
Graduate
01/14/2014

Additional Pathology Flashcards

 


 

Cards

Term
what are the parts of the neuromuscular system
Definition
peripherial nerves (sensors) and skeletal muscles(effectors
Term
what are the parts of the motor unit
Definition
peripherial component of the motor system
1 lower motor neuron
peripherial axon
NMJ
muscle fibers
Term
myelin: composition, amount, anatomy
Definition
schwann cells
one schwann cell per internode of one axon
intenodes are seperated by nodes of ranvier
Term
what are perineural cells
Definition
meningeal like cells that maintain blood nerve barrier of fasicles
Term
what determines nerve velocity
Definition
axon diameter combined with myelin thickness
Term
what nerves sense light touch
Definition
thick myelin, large diameter
Term
what nerves sense temp
Definition
unmyelinated thin axons
Term
what are the 2 patterns of nerve injury
Definition
axonal injury
demyelinating injury
Term
what are the 3 causes of axonal injury
Definition
damage to axon causes distal portion to degenerate
wallerian degeneration
axonal neuropathies
Term
what is a wallerian degeneration
Definition
secondary myelin loss
Term
what is an axonal neuropathy
Definition
decrease in axon density and amplitude of impulses
Term
how do axons regenerate
Definition
regrowth of axon and remyelination of distal axons
Term
what are the 3 types of demyalinating injuries
Definition
polyneuropathies
polyneuritis multiplex
mononeuropathy
Term
what are the consequence of demyelinating injury (4)
Definition
damage of schwann cells or myelin with axonal sparing
slow conduction velocity
occurs within random individual internodes (segmental demyelination)
axons develop thin myelin and short internodes
Term
how can an axon with a demyelinating injury be identified (3)
Definition
normal density
segmental demyelination
areas of repair
Term
polyneuropathies: clinical presentation
Definition
loss of sensation and paresthesia starting in toes and spreading to knees (simillar in hands)
"stocking and glove distribution:
Term
polyneuropathies: histology (3)
Definition
peripherial nerves affected in symmetric length dependent fashion
diffuse axonal loss
pronounced in distal segments of long nerves
Term
define polyneuritis multiplex
Definition
demyelinating injury randomly affects portions of individual nerves
Term
define mononeuropathy
Definition
demyelinating injury affects single nerve
Term
most common cause of mononeuropathy (2)
Definition
most common in traumatic injury or entrapment
Term
causes of demyelinating injuries (13)
Definition
DM
neuremia
thiamine deficiency
B6/B12 deficiency
drugs and toxins
vasculopltic: vasculitis, amyloidosis
inflammatory: autoimmune
infection
inherited
paraneoplastic: leukodistrophy
Term
what drugs cause demyelinating injuries (5)
Definition
vinblastine
vincristine
paclitaxel
colchicine
isoniazid
Term
what toxins cause demyelinating injuries (6)
Definition
alcohol
lead
aluminum
arsenic
mercury
acrylamide
Term
what autoimmune disorders cause demyelinating injuries (4)
Definition
SLE
RA
sarcoidosis
sjogern
Term
what infections cause demyelinating injuries (4)
Definition
HSV (ganglionitis)
leprosy
HIV
lyme (facial nerve palsy)
Term
what inherited disorders cause demyelinating injuries
Definition
charcot-marine tooth neuropathy 1, 3, X
hereditary neuropathy with liability to pressure palsy
Term
what are the causes of charcot-marine-tooth neuropathy 1, 3, X
Definition
1: AD duplication in PMP22
3: AD or AR point mutation in PMP22
X: X-linked connexin 32 gene mutation
Term
what is the cause of hereditary neuropathy with liability to pressure palsy
Definition
AD deletion in PMP22
Term
symptoms of guillian barre syndrome (3)
Definition
rapidly progressive
ascending motor weakness
can cause death due to resp M failure
Term
guillian barre syndrome histology (3)
Definition
injury more extensive in nerve roots and proximal segments
mononuclear infiltrates rich in macrophages
acute demyelination
Term
cause of guillian barre syndrome
Definition
autoimmune response: humeral and cellular response triggered by infection of vaccine
infection: camplobacter, EBV, CMV, HIV
Term
guillian barre syndrome treatment
Definition
plasmaphresis: remove offending antibodies
IVIG
supportive care: ventilation
Term
guillian barre syndrome prognosis
Definition
recovery is likley if patient survives initial acute phase
Term
cause of chronic inflammatory demyelination polyneuropathy
Definition
symmetric demyelinating disease of motor and sensory due to immune factors

increased in autoimmune disorders: SLE, HIV
Term
signs of chronic inflammatory demyelinating polyneuropathy (6)
Definition
chronic relapsing and remitting progressive course
difficulty walking, weakness, numbness, pain, tingling
Term
histolog of chronic inflammatory demyelinating polyneuropathy (2)
Definition
segments of demyelinating and remyelinating
schwann cells wrap in onion skin pattern
Term
treatment of chronic inflammatory demyelinating polyneuropathy (2)
Definition
plasmapharesis
immunosupressents
Term
prognosis of chronic inflammatory demyelinating polyneuropathy (2)
Definition
some recover completely
usuallo they have recurrent bouts causing permanent loss of nerve function
Term
what are the three types of diabetic peripherial neuropathy, which is most common
Definition
can occur alone or together
autonomic neuropathy
lumbosacral radiculopathy
distal symmetric sensorimotor polyneuropathy - most common
Term
signs of diabetic autonomic neuropathy (4)
Definition
change in bowel, cladder, cardiac, or sexual function
Term
signs of diabetic lumbosacral radiculopathy (3)
Definition
asymmetric pain
can progress to LE weakness and muscle atrophy
Term
signs of diabetic distal symmetric sensorimotor polyneuropathy (10)
Definition
sensory axons most affected: parasthesia, numbness
glycosylation end products
hyperglycemia
increased ROS
microvascular change sin axon metabolism
abnormal C protein levels
neurotrophic factors
axonal injury and demyelination
Term
tx distal symmetric sensorimotor polyneuropathy
Definition
strict glycemic control
Term
how do druges and toxins interfere with nerves (3)
Definition
interfere with axon transport or cytoskeletal function
longest axons most susceptible
Term
systemic vasculitis: 3 signs
Definition
patchy involvement
variation in degree of axonal damage between fasicles within nerve
mononuclear multiplex
Term
what is mononuclear multiplex
Definition
painful asymmetric sensory and motor preipherial neuropathy
Term
what are common signs of an inherited disease of peripherial nerves
Definition
demyelination of axon
show as adult and slowly progress
mimic acquired polyneuropathies
Term
what is the most common cause of inherited disease of peripherial nerves
Definition
mutation of PMP22 encoding myelin sheath protein
Term
how does the NMJ work
Definition
influx of Ca
release of ACh
diffuses across cleft
binds post synaptic receptor
depolarizes membrane
depolarizes myofiber
contraction of msucle
Term
cause of myasthenia gravis
Definition
autoantibodies block post-synaptic ACh receptor
degradation and depletion of receptors
can change self tolerance and allow generation of auto-reactive T and B cells
Term
who get smyasthenia gravis
Definition
any age
mostly female
Term
what conditions are associated with myasthenia gravis
Definition
60% have reactive hyperplasia of intrathymic B cells
20% have thymoma (epithelial cell tumor) which causes tolerance to self antigens and allows for generation of autoreactive T and B cells
Term
clinical signs of myasthenia gravis
Definition
ptosis
diplopia
fluctuating muscle weakness over short time
use causes more weakness
cholinesterase inhibitors improve strength
Term
tx myasthenia gravis
Definition
cholinesterase inhibitors
immunosupression
plasmaphresis
thymectomy
Term
prognosis myasthenia gravis
Definition
>95% 5 year survival with intervention
Term
cause of lambert-eaton syndrom
Definition
autoantibodies inhibit pre-synaptic Ca channels reducing ACh release
Term
signs of lambert-eaton syndrome
Definition
weakness improves with stimulation
often begins as paraneoplastic disorder esp small cell lung cancer
Term
tx lambert eaton syndrome
Definition
plasmaphresis
immunosupression
Term
prognosis lambert eaton syndrome
Definition
worse prognosis due to lung cancer association
Term
cause of congenital myasthenic syndrome
Definition
heterogenous disorders
mutations dirupt function in various NMJ proteins (pre-synapse, synapse, post-synapse ACh activity)
Term
what produces tetanus toxin
Definition
clostridium tetani
Term
tetanus toxin MOA
Definition
neurotoxin blocks action of inhibitor interneurons increasing ACh
Term
tetanus toxin effect
Definition
tetanospasm: sustained muscle contraction and spasm
Term
MOA and effect of botulinium toxin
Definition
inhibits ACh release
flaccid paralysis
Term
what are the NMJ disorders
Definition
myasthenia gravis
lambert eaton syndrome
congenital myasthenic syndromes
tetanus toxin
botulinium toxin
Term
what are the periperhail nerve sheath tumors
Definition
schwannoma
neurofibromas
malignant
Term
traumatic neuroma: cause
Definition
non-neoplastic proliferation caused by pervious injury to peripherial nerves
Term
traumatic neuroma: clinical sign
Definition
painful localized nodule
Term
traumatic neuroma: morphology
Definition
axonal regeneration after transection causes aprouting and elongation of processes from axonal stump

nodules: axons, schwann cells, CT

if perinerum is disrupted: processes may miss distal end of nerve

if processes are induced: reactive schwann cell proliferation occurs
Term
in general, who gets peripherial nerve sheath tumors
Definition
usually adults
often familial association with NF1 and NF2
Term
in general, what are signs of nerve sheath tumors
Definition
pain or loss of function due to impingement of nerve or surrounding structures
Term
in general, waht are histological signs of nerve sheath tumors
Definition
soft tissue mass
schwann cell differentiation
Term
schwannoma; location, spread
Definition
benign encapsulated tumors
in soft tissue, internal organs, spinal nerve roots
Term
statistics on schwannoma cause
Definition
10% associated with NF2 (multiple and bilateral vestibular schwannoma)
90% sporadic
Term
cause of schwannoma
Definition
due to loss of function mutation in CH22 merlin gene which is a cytoskeletal tumor supressor via E-cadherin contact inhibition

schwanomatosis
Term
what is schwanomatosis
Definition
familial multiple schwanoma without vestibular schwanomas due to loss of function in CH22 tumor supressor protein for chromatin structure regulation
Term
schwanoma histology
Definition
circumscribed masses adjacent to nerves
axons excluded from tumor
antoni A dense areas
antoni B loose areas
uniform proliferation of neoplastic schwann cells
thick walled hyalinized vessels
Term
antoni A area composition
Definition
spindle cells, buckled nuclei in fasicles, align to make bands of verocay bodies (aneuclar mass)
Term
neurfibroma types
Definition
localized cutaneous neurofibromas
plexiform neurofibromas
diffuse neurofibromas
Term
localized cutaneous neurofibroma signs
Definition
superificial nodular polypoid tumors
solidary sporadic lesions
multiple NF1
Term
plexiform neurofibromas: location, association, risks
Definition
grow diffuse in nerve or nerve plexus
difficult to remove without neurological deficits
pathognomic for NF1
small risk of malignant transformation
Term
difuse neurofibromas: describe, associations
Definition
infiltrative proliferations
large disfiguring SC masses
associated with NF1
Term
neurofibroma histology
Definition
not encapsulated
circumscribed when localized, can be diffuse
neoplastic schwann cells mised with other cells (like mast cells)
loose wavy vollagen or myxoid, dense collagen filler
Term
histology of diffuse neurofibromas
Definition
infiltrative growth within dermis and subcutis
Term
histolog of plexiform neurofibromas
Definition
multiple fasicles of individual affected nerves
axons embedded within neoplastic proliferation
expand fasicles but leave perinerium intact
Term
malignant nerve sheath tumor associations
Definition
50% of malignant nerve sheath tumors nave NF1
10% of NF1 have nerve sheath malignancy
Term
cause of malignant nerve sheath tumors
Definition
origin from peripherial nerve
transformation of neurofibroma (usually plexiform)
Term
histolog of nerve sheath malignancy
Definition
schwann cell derivation
large poorly defined soft tissue mass
malignant features (anaplasia, necrosis, infiltrative growth, pleomorphism)
alternating areas of high and low cellularity (marbling)
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