Neurological mechanism of disease Flashcards
six disorders that will cause neurollogical disorders
- vascular
- neoplastic
- infectious
- degenerative
- neurotransmitter
- seizure disorders
T/F arterial blood flow interruption is a common probelm
true
what determines the symptoms resulting from an interuption in arterial blood flow
the vessel affected
length of ischemia
neurologic redundancy
what is the most common neurological disorder in the US
incidents per year
deaths
CVA (stroke)
500,000/yr
150,000 deaths/yr
what are 4 comorbidities associated with CVA
HTN
DM I/II
obesity
smoking
describe the stroke belt
a statistical band across the southeastern US where strokes are more common
CVA working definition
condition resulting in an abrupt appearence of neurlogical symptoms due to focal vascular disruption that usually involves an infarction
two types of strokes
ischemic strokes
hemorrhagic strokes
what type of stroke is most common
ischemic (85-90% vs 10-15%)
two types of ischemic strokes
thrombotic
embolic
differentiate between thrombotic and embolic ischemic strokes
thombolic comes from clot formation due to rupture of an artheroscleroctic plaque, similar to AMI
emoblic involves piece breaking off an existing clot and lodging in the cerebreal vessle
two types of hemorrhagic strokes
intracerebral hemorrhage
subarachnoid hemorrhage
what condition is commonly associated with intracerebral hemorrhage
HTN
what typically causes subarachnoid hemorrhage
bleed from a major cerebral artery in the circle of willis, often from congenital vessel weakness
what is the most common location of aneurysm in the brain
anterior cerebral or communicating artery
two common sources of embolic strokes
carotid
cardiac
what forms carotid clots leading to embolic stroke
what might be heard on auscultation
what is the surgical treatment
atherosclerotic lesions
bruits
endarterectomy
what is the most common source of cardiac emboli
mural thombi from atrila fibrillation
how can thrombopphlebitis (DVT) can an embolic stroke
passing between a atrial septal defect
what side of the face will have deficits from a right sided stroke?
what side of the body>
ipsilateral face
contralateral body
right stroke will cause right facial deficits and right peripheral deficits
common ischemic stroke symptoms
usually none other than mild neurological deficits, possibly a mild head ache and decreased LOC
common symptoms of hemorrhagic strokes
“worst headache of my life”
decline in LOC
why is stroke prognosis difficult to predict
one area can be damaged but other areas can be repurposed to compensate
why is time a necessary to determine the fullt extent of damage caused by a stroke
the infarcted area can be under perfused so the extent of the infarcted tissue might not be known for weeks
what is sequela of stroke that can lead to early disfunction
increased intracranial pressure
what are goals of treating an ischemic stroke
reduce the size of infarction if possible
provide rehab
prevent future strokes
what methods can be used to reduce infarction
anticolagulation with IV heparin
IV thrombolytic therapy
cerebreal artery catherization and angioplasty
what is an important consideration when treating hemorrhagic stroke
anticoagulation and antithrombolytics are contraindicated in hemorrhagic stroke
four strategies to prevent future strokes
reduce the chances of repeat embolis
control HTN
control DM
treat atherosclerosis
two special categories of CVA
TIA
silent strokes
define TIA
stroke like deficits that with occur and resolve rapidly, usuallly within 60minutes
what is the maximum time limit before recovery for a TIA
24 hours
what is the most likely cause of a TIA
small emboli from heart or carotids
what is the risk of TIA
they can progress to a full stroke without treatment
silent stroke
a true stroke that causes infarction in a portion of the brain with no obvious motor or sensory functions
possible changes associated with recurrent silent stroke
change in mood/personality
vascular dementia
most CNS tumors come from what cells
glial cells
what is the determinant of symptoms caused by a brain tumor
location and size of tumor
what will be the difference in distribution from a primary and secondary CNS tumor
primary will be more localized
secondary will be more diffuse
what portion of brain tumors are malignant
how many deaths per year
50%
13000/year
what are the risk factors for CNS tumors
radiation exposure
no other risk factors known
what are the 3 most common CNS tumor histologies
gliomas
meningiomas
schwannomas
three types of gliomas
which is the most common
astrocytoma (common)
oligodendrogliomas
ependymomas
5 grades of astrocytomas
which are most common in children
adults
I-IV
I and II most common in children
IV in adults
specific name for grade IV astrocytoma
glioblastoma multiforme
three general symptoms of a primary CNS tumor
headache (CC in 30%)
sz
nausea
emesis
specific symptoms associated with primary CNS tumor
focal neurological deficits dependent of the location
symptoms associated with primary frontal lobe tumor
personality changes
decreased intellect
symptoms associated with primary temporal lobe tumor
sz
olfactory and gustatory hallucinations
deja vu/jamais vu
symptoms associated with primary parietal lobe tumor
sensory or motor deficits
spontaneous pain symdromes
symptoms associated with primary occipital lobe tumor
visual field defects
visual agnosia (cant recognize what you are seeing)
symptoms associated with primary brain stem or cerebellar tumor
ataxia
nystagmus
cranial nerve palsies
what is the preferred imaging method for brain tumor
how might the histology of the tumor be idenified
MRI over CT
tissue biopsy via needle or craniotomy
three general treatment options for CNS tumors
surgery, chemo, radiation
speficific treatment for prolactinomas
dopaminergic drugs
radiation options for CNS tumor treatment
whole brain vs focused radiation (gamma knife)
prognosis for:
pituitary tumors
meningiomas
astrocytomas
pituitary good
meningiomas usually good
astrocytomas usualyl bad
what is the median survival of a low grade (I-II) astrocytomas
Grade III?
Grade IV?
5-10 years
3 years
<1yr
how can a bioengineered polio virus treat glioblastomas
its been genetically engineered to only be able to infect cancer cells, killing the cancer cells and stimulating the immune response
three CNS infections that can cause neurologic symptoms
meningitis
encephalitis
abscess
5 types of meningitis
acute
purulent
septic
chronic
aseptic
4 key principles of CNS infections
not age dependent
follow acute or chronic course
can be lethal or cause long term disability
there are a wide range of possible pathogens
common clinical indications of CNS infection
signs of infection (fever, malaise)
alteration of CNS function (AMS, SZ)
how quickly will acute meningitis present symptoms
classic symptoms
causes for adults
causes for kids
very quickly
fever, stiff neck, headache, AMS, petechial skin rash
strep pneunmoniae, neisseria meningitidis
strep plus hemophilus
differentiate between chronic and acute meningitis
usually a longer clinical course
similar, but less severe symptoms
usually cuased by mycobacteria, fungi, treponema
two indications of aseptic meningitis
more benign course
usually caused by viral infection (herpes, mumps, enteroviruses)
how is meningitis diagnosed
lumbar puncture and culture
how is meningitis treated
antimicrobial drugs
prevention through vaccines or prophylactics
prognosis for bacterial or fungal meningitis without treatment
with treatment
bacterial and fungal usually fatal, viral usually not fatal
with treatment most patients will survive but may have deficits
three examples of post meningitis deficits
hearing loss
impaired cognition
epilepsy
what are the common causes of encephalitis (examples)
viruses
rabies, measels, polio, herpes, west nile
T/F CNS tumors commonly form from neurons
false, they usually come from support cells
what causes symptoms in brain abcesses
increased ICP
destruction of brain tissue
what is the usual source of brain abcesses
what are some potential sources of pathogens that cause brain abcesses
what are the two pathological processes related to degenerative neurological disorders
gradual loss of neurons
gradual loss of axons
three examples of neuronal loss disorders
dementia
ALS
parkinsons
dementia
generalized loss of neurons
ALS
amyotrophic lateral sclerosis, loss of upper and lower motor neurons
parkinsons disease
loss of extrapyramidal motor neurons
examples of neural pathway disruptions
MS
guillain barre
what are the symptoms associated with dementia
loss in
memory, reasoning, judgement, abstraction, learning, language
four risk factors for dementia
age
female
head injury
chronic disease (athersclerosis, DM)
three ways to reduce dementia risk
intellectual stimulation
social interaction and exercise
statins and nsaids
three most common causes of dementia
alzheimers
vascular dementia from multiples infarcts
lwey body dementia
what is the histological pathophysiology of alzheimers
plaques of beta amyloid
tangles of tau proteins
what is expected with alzheimers progession of disease
steady loss of memory, speech, motor function
average life span of 7-8 years
what are the current treatment goals for alzheimers
slow the progression of disease
reduce plaques with anti amyloid drugs (possibly not beneficial)
prevention of alzheimers
statins may reduce risk up to 50S%
NSAIDs
occurance of MS
350,000, 2-1 women to men
what age is mostly likely for the onset of MS
20-40
what causes MS
areas of demylination in the CNS, followed by inflammation and gliosis (scarring)
three types of MS
relapsing-remitting
primary progressive
secondary progressive
three characteristics of relapsing-remitting MS
intial symptoms resolve or significantly improve over weaks
months or year can go by before a new lesion forms
eventual decrease in remission and increasing disability
three diagnostic indicators of MS
clinical course and neurologic findings
MRI of brain and spine
testing of CSF for oligoclonal bandsof IgG
common symptoms of MS
limb weakness, numbness, paresthesia
spastic paraparesis
optic neuritis
diplopia
loss of sphincter control
vertigo
four common MS treatments
corticosteriods (prednisone, medrol)
interferon beta 1a
immunosuppresants
IVIG
Gullian barre syndrome (acute, idipathic polyneuropathy)
rapidly progressive motor paralysis with likely spontaneous recovery
what causes GBS
autoimmune antibodies produced against myelin
T/F most GBS has no trigger event
false
four triggers for GBS
food poisoning caused by campylobacter jejuni
cytomegaloy virus/epstein barr
mycoplasmic pneumonia
some vaccinations
what is the key feature of GBS
ascending paralysis progressing over hours or days
what is the first symptom of GBS
how does this progress
usually leg weakness
motor loss comes first, then sensory
T/F autonomic dysfunction and facial paralysis can occur in GBS
true
what is the treatment for GBS
is this time sensitive?
IVIG
plasmapheresis
yes time is a factor, hours matter
describe the course of recovery for GBS
recovery begins 1-4 weeks after onset
can take months or a year to complete
how severe is GBS
it can be mild or severe, but most require hosptialization and 30% of severe GBS can require mechanical ventiliation
what accounts for the 1-4% fatality rate of GBS
pulmonary complications or cardiac arrhythmias
three categories of neurotransmitter diseases
disorders of
deficiency of a neurotransmitter
excess of a neurotransmitter
imbalance of neurotransmitters
two diseases caused by a deficiency of a specific neurotransmitter
parkinsons (dopamine)
myasthenia gravis (acetylcholine)
what is neurological condition is caused by an excess of dopamine
psychosis
two disorders caused by an imbalance of neurotransmitters
chronic depression or psychosis
myasythenia gravis
a chronic autoimmune disease caused by antibodies against acetylcholine receptors at the neuromuscular junction
three common presenting symptoms of myasthenia gravis
ptosis
diplopia
dysphagia
what is the progression of myasthenia gravis
85% will develop generalized muscle weakness notably with repetitive muscle use
what is a common accompaniment with lewy body dementia
hallucinations
T/F vitamin B deficiency can cause dementia
true
10-15% of MG patients have a ____
3-8% will have or will develop ____
thymoma
hyperthyroid (graves disease)
three treatment options for MG
thymectomy (if present and the patient is between puberty and 60)
acetylcholinesterase inhibitors
immunosuppresive drugs
seizure
abnormal or excessve and synchronized discharge of CNS neurons
epilepsy
recurrent seizures with a chronic, underlying cause
four causes of isolated seizures
drug withdrawl
high fever
infections
vasovagal or orthostatic syncope
two etiology categories of epilepsy
primary and secondary
what is the most common type of epilepsy
when does it usually start
primary (idiopathic or constitutonial)
usually before age 20
four causes of secondary epilepsy
intracranial neoplasms
post head trauma
post meningitis
others
four types of generalized seizures
tonic-clonic
absence
myoclonic
febrile
partial sz (retain consciousness)
partial (single muscle group/limb)
complex (sensory hallucinations with increased or decreased motor function
four phases of a tonic-clonic seizure
LOC, tonus or clonus, apnea, flaccid coma, post ictal
how long does the tonic phase of a tonic clonic sz last
clonic phase
1minute
2-3 minutes
four features of the post-ictal phase
headache/confusion
fatigue
muscle soreness
duration of up to several hours
three pronged approach to preventing sz
enhance inhibitory CNS influences (GABA)
reduce excitatory CNS influences (glutamate)
modulate ionic conductance
non pharmacologic treatment
neurosurgical ablation/excision of lesion
vagus nerve stimulation for partial sz
success rates of conventional seizure treatment
70% seizure free on one drug
20% sz on 2 or more drugs
remaining 10% unresponsive
