Shared Flashcard Set

Details

Path PNS
KYCOM Block 13
72
Pathology
Graduate
01/27/2014

Additional Pathology Flashcards

 


 

Cards

Term
what is the neuromuscular system composed of
Definition
peripherial nerves (sensors)
skeletal muscles (effectors
Term
what is the principal component of the motor system
Definition
motor unit
Term
what is a motor unit made of 4ch
Definition
1 lower motor neyron
peripherial axon
NMJ
muscle fiber
Term
myelin: what makes it, anatomy, function
Definition
made by schwann cells
one schwann cell per multiple nodes of axon
internodes reparated by nodes of ranvier
axon diabeter combined with myelin thicnkess determines velocity
Term
what is a perinural cell
Definition
meningeal like cell that maintains blood nerve barrier of fasicles
Term
what type of nerves sense light toch
Definition
thick myelin
large diameter axons
Term
what type of nerves sense temp
Definition
unmpelinated thin axons
Term
what are the 2 patterns of nerve injury
Definition
axon injury
demyelinating injury
Term
how does axonal injury occur
Definition
damage causes distal portion of axon to degenerate
Term
what are the three types of axonal injury, explain
Definition
wallerian degeneration: secondary to myelin loss

axonal neuropathies: decrease axon density and amplitude of impulses

regeneration: regrowth of axon and remyelination of distal axon
Term
what is a demyelinating injury, what does it do to conduction, where does it occur
Definition
damage of schwann cells or myelin with axon sparing causes thin myelin sheaths and short internodes

slows conduction velocity

occurs at random internodes (SEGMENTAL)
Term
what are the 3 demyelinating injuries
Definition
polyneuritis
polyneuritis multiplex
mononeuropathy
Term
polyneurmmetricopathy: define, location
Definition
peripherial nerve affected in symmetrically length wise, more pronounced at distal segments

diffuse axonal loss
Term
polyneuropathies: clinical presentation
Definition
stockin and glove distribution: loss of sensation and paresthesia starting in toes to knees and hands to elbows
Term
polyneurs multiplex define
Definition
demyelination randomly affects all portions of indivdual nerves
Term
mononeuropathy define, when does this happen
Definition
demyelination of a signle nerve
traumatic injury or entrapment
Term
nutritional causes of demyelination 5
Definition
DM, neuremia, deficient thiamine, B6, B12
Term
toxic causes of demyelination 6
Definition
drugs, alcohol, lead, aluminum, aresnic, mercury, acrylamide
Term
vascular causes of demylation 2
Definition
vasculitis
amyloidosis
Term
inflammatory causes of demyelination 4
Definition
autoimmune: SLE, RA, sarcoidosis, sjogerns
Term
infectious causes of demyelination 4
Definition
HSV (ganglioniitis)
leprosy
HIV
lyme (facial nerve palsy)
Term
inherited causes of demyelination 4 (explain issue in each)
Definition
charcot-marine-tooth (CMT) neuropathy 1: AD duplication in PMP22

CMT neuropathy 3: AD/AR point mutation in PMP22

CMT neuropathy X: X-linked connexin 32 gene mutation

hereditary neuropath with liability to pressure palsy: AD deletion in PMP22
Term
paraneoplastic causes of demyelination 1
Definition
leukodystrophy
Term
what are the 6 demyelinating dosorders
Definition
guillian barre syndrome
chronic inflammatory demyelinating polyneuropathy
Term
guillian barre syndrome: what caises damage disease, how does it present, location
Definition
mononuclear infiltrates cause rapidly progressive demyelination causing ASCENDING MOTOR WEAKNESS
Term
how do people with guillian barre die
Definition
failiure of respiratory muscles during ascending motor weaness
Term
guilliane barre: cause 2
Definition
autoimmune response: humeral and cellular response triggered by infection or vaccine

infection: camplobacter jejuni, EBV, CMV, HIV
Term
TX 3 and prognosis guillian barre
Definition
plasmaphresis (remove offending antibody), ivig, supportive care (ventilation)

recovery is likley if patient survives initial acute phase
Term
chronic inflammatory demyelinating polyneuropathy: cause, presentation
Definition
symetric demyelinating disease (MOTOR AND SENSORY) the is immune mediated
Term
what disorders is chronic inflammatory demyelinating polyneuropathy seen in 2
Definition
HIV, SLE
Term
signs of chronic inflammatory demyelating polyneuropathy 7
Definition
chronic relapsing and remitting progressive course
difficulty walking, weakness, numbness, pain, tingling
Term
cellular changes in chronic inflammatory demyelinating polyneuropathy 2
Definition
segments of demyelination and remyelination
schwann cells wrap in ONION SKIN pattern
Term
chronic inflammatory demyelinating polyneuropathy tx and prognosis
Definition
tx: plasmapharesis and immunosupression
some pt recover completely, usually pt has recurrent bouts causing permanent loss of nerve function
Term
peripherial neuropathy most common cause
Definition
long term diabetes
Term
types of diabetic peripherial neuropathy 3, which is most common
Definition
autonomic
lumbosacral
distal symmetric sensorimotor polyneuropathy - most common
Term
signs of autonomic neuropathy 4
Definition
bowel, bladder, cardiac, or sexual dysfunction
Term
lumbosacral radiculopathy 3
Definition
asymmetric pain, can progress to LE weakness and muscle atrophy
Term
dystal symmetric sensorimotor polyneuropathy - signs and why
Definition
sensory axons most affected (parasthesia and numbness) with features of axon injury AND demyelination
Term
causes of distal symmetric sensorimotor polyneuropathy 6
Definition
glycosylation end products
hyperglycemia
increased ROS
microvascular changes in axon metabolism
abnormal protein C levels
neurotropic factors
Term
tx distal symmetric sensorimotor polyneuroopathy
Definition
strict glycemic control
Term
how do drug and enivormental toxins cause damage to nerves, location
Definition
interfere with axon transport or cytoskeletal function
longest axons most susceptible
Term
how does systemic vasculitis damage nerves, where
Definition
patchy involvement
variation in degree of axon damage between fascivle within a nerve

mononeuritis multiplex: painful asymmetric sensory and motor peripherial neuropathy
Term
inherited diseases of peripherial nerves: when do they show up, what causes damage, most common
Definition
demyelination of axon
show as adult and slowly progress
mutation in PMP22 gene encoding myelin sheath protein
Term
how does the NMJ normally work
Definition
influx of Ca
release of ACh
diffuses across cleft
binds post-synaptic receptor
depolarizes membrane
depolarizes myofiber
contraction
Term
what are the 4 NMJ disorders
Definition
myasthenia gravis
lambert eaton syndrome
congenital myasthenic syndromes
infection
Term
myasthenia gravis: cause
Definition
autoantibodies develop self tolserance and allow generation of out reactive T and B cells

autoantibodies block post-synaptic ACh receptor causes degradation and depletion
Term
what are 3 diseases or common associations with myasthenia gravis
Definition
mostly female
60% have reactive hyperplasia of intrathalamic B cells
20% have thymoma(epithelial cell tumor) that causes tolerance to self antigens and allows for mectomyautoreactive T and B cells
Term
clinical signs of myasthenia gravis: 5
Definition
ptosis
diplopia
fluctuating muscle weakness over short time
MORE WEAKNESS CAUSED WITH USE
CHOLINESTERASE INHIBITORS IMPROVE STRENGTH
Term
tx 4 and prognosis of myasthenia gravis
Definition
tx: cholinesterase inhibitors, immune supression, plasmapharasis, thymectomy

worse prognosis due to lung cancer association
Term
lambert eaton syndrome: cause
Definition
autoantibodies inhibit PRE SYNAPTIC CA CHANNELS reducing ACh release
Term
signs of lambert eaton syndrome 2
Definition
WEAKNESS IMPROVES WITH STIMULATION
often begins as a paraneoplastic disorder (ESP SMALL CELL LUNG CANCER)
Term
lambert eaton syndrome tx 2 and prognosis
Definition
tx: plasmapharesis, immunesupression
worse prognosis that myasthenia due to lung cancer association
Term
congenital myasthenic syndromes: inheritance, cause
Definition
heterogenous group of disorders
mutations disrupt function of various NMJ proteins stopping pre-synaptic, synaptic OR post synaptic ACh activity
Term
what two infections cause NMJ disorders, how, what sign
Definition
tetanus toxin: neuro toxin blocks action of inhibitor interneurons increasing ACh causing tetanospasm (sustained muscle contraction and spasm)

botulinium toxin: inhibitors ACh release causing FLACCID PARALYSIS
Term
peripherial nerve sheath tumors: who usually gets them, causes, general clinical sign, 2 histological changes
Definition
usually in adults
often familial association with NF1 and NF2
pain or loss of dunction due to impingement of nerve or surrounding structures

soft tissue mass, schwann cell differentiation
Term
what is the function of a schwann cell
Definition
schwann cells myelinate the PNS
Term
2 causes of schwannoma
Definition
90% sporadic
10% associated with NF2
Term
what is the presentation of a schwannoma associated with NF2
Definition
multiple BILATERAL vestibular schwannoma
often affects CN 8 are cerebellar pontine engle decreasing hearing causing tinnitus
Term
cause of sporadic schwannoma
Definition
loss of function mutation in ch22 merlin gene which is a cytoskeletal tuomor supressor via E-cadherin contact inhibition
Term
cause of schwannomatosis
Definition
familial multiple schwannomas without vestibular schwannomas due to loss of function in Ch22 tumor supressor protein for chromatic structure regulation
Term
histological changes in schwannoma 8
Definition
circumscribed mass adjacent to nerves
axons excluded from tumor
antoni A (Dense) areas
antoni B (loose) areas
uniform proliferation of neoplastic schwann cells
thick walled haylanized vessels
S100+
Term
what are the 3 types of neurofibromas
Definition
localized cutaneous neurofibromas
plexiform neurofibromas
diffuse neurofibromas
Term
localized cutaneous neurofibromas: what is it, cause
Definition
superificial nodular polypoid tumors, solitary sporadic lesions
multiple in NF1
Term
plexiform neurofobromas: what is it, cause, complication
Definition
grow diffusley within nerve or nerve plexus
difficult to remove
pathognomic for NF1
small risk of malignant transformation
Term
diffuse neurofibromas: what is it, cause
Definition
infiltrative proliferations
large disfiguring SC masses
associated with NF1
Term
histological changes in neurofibromas
Definition
not encepsulated
circumscribed: localized cuteneous neurofibromas
diffuse infiltrative
neoplastic schwann cells mixed with other cell types (mast cells)
loose wavy collagen or myxoid or dense collagen fiber

plexiform or diffuse
Term
describe a plexiform neurofibroma
Definition
multiple fasicles of individual affected nerves
axons embedded within neoplastic proliferation
expand fascicles but leave perinerium intact
Term
describe a diffuse neurofibroma
Definition
infiltrative growth within dermis subcutis
Term
cause of malignant nerve sheath tumors
Definition
originate from a peripherialnerve
transform from neurofibroma (usually plexiform)
50% associated with NF1
10% of NF1 have malignant nerve sheath tumor
Term
morphology of malignant tumors in adults 4
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)
Term
traumatic neuroma: cause, effect, symptom
Definition
previous injury of peripherial nerve goes through non neoplastic proliferation that is painful and localized
Term
morphology of traumatic neuroma
Definition
axonal regeneration after transection causes spouting and elongation of processes from axonal stump
nodules: axons, schwann cells, CT
if perineurium is disrupted: processes may miss distal end of nerve
if processes induced: reactive schwann cell proliferation
Supporting users have an ad free experience!