Neurological infections Flashcards
types of neurological infections
by location:
-in brain, spinal cord or meninges
by microbe:
most often viral or bacterial
for a neurological infection ______ has to enter into CNS
pathogen has to enter into CNS - CNS tightly guarded
pathogen entry into CNS by:
- fracutre of cranium
- compromised blood brain barrier
- direct extension from a contigous area (cotigous area=conjoining area, contigous areas w brain are middle ear, oral cavity, scalp)
- along axon (where nerves, cord, etc enter & exit)
Bacterial meningitis
- meningeal inflammation due to bacterial infection
- is life threatening (d/t lack of space compresses brain)
Etiology of Bacterial meningitis
-bacteria enters cranium (could be any bacteria but 2 common ones) :
streptococcus pneumonia
neisseria meningitidis (meningoccal meningitis) both are present in nasopharynx if become established there can go to cranium
predisposing factors to bacterial meningitis
- head trauma
- post neuro surgery
- congruent infection (eg. sinusitis, infection in middle ear getting into brain, infection in sinus getting to brain)
- immunocomprimised (decreased immunity)
Patho of bacterial meningitis
- bacteria proliferation & lysis of bacteria cell, normal cells & defense cells causing inflammation
- vascular congestion & infarct
- mennigeal thickening & adhesion
- Flow of CNS obstructed
- purulent exudate (pus) on brain & surface in CNS
what is hydrocephalus
water on brain, CSF accumulation in ventricles, ventricles expand needs more space, intracranial pressure & CSF
mnfts of bacterial meningitis
- fever
- headache (not a systemic mnfts a local mnfts), Nausea & vomiting (resulting from reflexes for both theses in brain, d/t swelling stimulate reflex centers causing nausea & vomiting)
- nuchal rigidity(neck stiffness) , back pain (from inflammatory changes in brain
- usually postive for Brudzinkskis & Kernigs Signs
diagnosing bacterial meningitis
-history, physical exam (involves part of neuro exam, kernigs & brudzinskis)
-C & S
-CSF: protein content will be elevated due to inflm causing marcrophages, nuetorphile, purulent exudate pus
decreased glucose in CSF because bacteria metabolizing glucose
Treating bacterial meningitis
- Antibioitcs
- Steroids (as anti-inflammatory) (deal with inflm because lysis is already happening, more lysis will happen with antibiotics causing more inflm)
Treating bacterial meningitis
- Antibiotics
- Steroids (as anti-inflammatory) (deal with inflm because lysis is already happening, more lysis will happen with antibiotics causing more inflm)
Viral meningitis
- aseptic meningitis
- d/t several different viruses (virus causing mumps most common virus)
- usually self-limiting (takes about 2 wks for body to deal with infection)
most common virus causing viral meningitis is
mumps
Viral meningitis is usually ________ limiting
self limiting: (takes about 2 wks for body to deal with infection)
-cannot leave alone to let cure though, monitor & treat mnfts that arrive not treating the viral infection
where do viruses replicate
inside cells
patho for viral meningitis
patho same as bacterial meningitis but happens within cells
what will happen to CSF during viral meningitis
- Increased lymphocytes (dealing with virus)
- moderately increased proteins compared to bacterial (less severe, less exudate)
- normal glucose (virus does not metabolize glucose)
treatment for viral meningitis
symptomatic treatment for viral meningitis because self-limiting
What is Encephalitis
inflm of parenchyma (brain or spinal cord)
encephalitis usually caused by
VIRUS that gets into brain, can be caused by bacteria
2 common types of viruses that cause encephalitis
- herpes simplex type 1
- arbovirus (arthropods = crustaceans, lobsters, Ticks)
Patho for encephalitis
- localized necrosis & hemorrhage then generalized then edema
- degeneration of cell bodies (because virus affects cellls & replicate inside cells)
- course is unpredictable (no uniform presentation)
mnfts of encephalitits
- headache, fever, nuchal rigidity (same as meningitis)
- lethargy, seizures, coma
- arboviurs usually self-limiting subsides in 2 wks
- herpes simplex more severe (severe neurological impairment, possibly can end up with dementia) (30% mortality rate with herpes simplex)
arboviurs that causes encephalitis is usually __________ and subsides in
self-limiting and subsides in 2 wks
herpes simplex is more
severe may cause severe neurological impairment (possibly pt can end up with dementia )
treatment for encephalitits caused by herpes simplex 1
aggressive treatment (IV acyclovir) antiviral
with bacterial meningitis pt usually presents positive for what signs
- kernigs
- brudzinskis
kernigs sign
pt lies on back lifts legs to 90 degree angle, tries to straighten leg, pain and resistance when trying to straightene leg
brudzinskis sign
patient lies prone with knees flexed, try to flex neck pain and resistance in neck
