Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
66 Cards in this Set
- Front
- Back
what is meningitis?
|
inflammation of the meninges
|
|
what is encephalitis
|
inflammation of the brain matter
|
|
where does CSF and blood vessels flow
|
in btw arachnoid and pia matter
|
|
where do most CNS infections orginate?
|
upper respiratory tract
|
|
what is the most common pathogen associated with CNS infections
|
Strep Pneumo
|
|
what are the possible ways that inctious material can enter to the CNS
|
sinusitis, Upper respirtatiory tract infection, from the blood, invasive injury.
|
|
what are some way that infectious entities enter the CNS from the blood following primary bacteremia
|
paracellular transport after disruption of tight junctions of BBB
transport within phagocytic cells such as monocytes transcellurlar transport within endothelial cell vacuoles. |
|
When should you do LP on neonate
|
unwell
fever,septic lethargic/irritable apnea neurological signs rash at least 3 above |
|
when should you do LP on 1-18months
|
fever
lethargic/irritable seizures bulging fontanelle rash |
|
when should you do LP anyone over 18 mos
|
fever
photophobia headache seizure nausea/vomiting stiff neck petichial rash |
|
what is the differential for CSF pleocytosis
|
infection: bacterial, viral, tuberculosis, fungal, protozoa
intracranial lesion near the subarachnoid space: malignancy, abscess, demyelination, infarct, hemorrhage, vasculitis. recent seizure radiation therapy injection of drug into the intrathecal space. |
|
what is important to remember when ordering tests on CSF
|
you need at least 6ml to perform every test needed on CSF. if you have less that 6 ml you must get cell count and chemistry and then all other tests must be prioritized.
|
|
what is the expected difference in cell/ul between viral and bacterial meningitis?
|
bacterial will have 500-10,000 cells and viral will have 10-500. basically greater than 500-700 you are going to be much more likely to assume bacterial infection
|
|
what is the expected neutorphil findings in bacterial and viral menignitis on LP
|
close to or greater than 90% neuts for bacteria
early viral can be higher than 50 but late is usually less than 20% |
|
what is the expected glucose findings difference btw bacterial and viral meningitis in LP
|
bacterial should be less than 40mgs
viral will probably be 45-85 |
|
what is the CSF/serum glucose found in LP difference btw bacterial and viral
|
bacterial less than 0.6
viral more than 0.6 |
|
what is the exptected protien amount difference in LP for bacterial and viral mengitis
|
bacterial greater than 150
viral less than 100 |
|
what is a hot specimen of CSF
|
opaque due to high white count indicates bacterial menigitis
|
|
what is the normal cell count of CSF and what is usually the type of cell found?
|
1-5
mainly monocytes |
|
what is the main cell type found on LP in viral menigitis
|
lymphocytes
|
|
what are the two types of meningitis?
|
septic and aseptic
|
|
what is the primary cause of septic meningitis?
|
bacterial
|
|
what is the primary cause of aseptics meningitis
|
viruses, fungi, mycobacterium tuberculosis
|
|
when would protein be elevated in aseptic meningitis
|
with M. tuberculosis infection.
|
|
what are the two leading causes of bacterial menigitis
|
step pneumo
neiseria meningitidis |
|
what are some neurological sequelae for bacterial meningitis
|
hearing loss
focal neurological deficits cognitive impairment |
|
what is a common cause of neonate menigitis recieved from the mother
|
Group B streptococcus from a colonized mother passing to child during birth.
|
|
what laboratory test that was once used to diagnose bacterial meningitis is now considered bad
|
latex agglutination
|
|
what are the predominate bacterail agents of meningitis
|
streptococcus pneumoniae(1st)
haemophilus influenza (pediatric not vaccinated ) neiseria meningitidis(2nd) listeria monocytogenes(pregnant females teens to 30s) staphylococcus aureaus gram neg organisms |
|
where does pneumococcal meningitis orginate
|
mucosal colonization of nasopharynx
|
|
what population is most at risk for pneumococcal meningitis
|
child in crowded area(day care)
if adult usually from crowded area |
|
what are the common cases that see coagulase negative staphylococci
|
in patients with CNS shunts or have recently undergone neurological procedures.
coagulase-neg staphylococci is a skin organism |
|
what are most commong seen bugs in head trauma meningitis
|
coagulase-neg staphylococci
staphylococcus aureus pseudomona aruginosa |
|
what are some features of acute viral meningitis that differentiate it from bacterial
|
less severe
shorter in duration less than 1000 usually less than 500 white count in CSF predominating lymphocytes normal glucose opening pressure is normal or only slightly elevated |
|
what should you be thinking if there is lowered glucose in an otherwise assumed viral meningitis
|
mumps
lymphocytic choriomeningitis |
|
what is the gold standard of diagnosis of acute viral meningitis
|
PCR can be done in 2 hours
culture-takes 24 hours serology- only good for classifying or screening not diagnostic |
|
what are the etiological agents of viral meningitis
|
enterovirus(coxsackie, echovirus)
herpes simplex virus type 1, 2 mumps varicella-zoster lymphocytic choriomeningitis HIV |
|
what are the two major causes of viral meningitis
|
enterovirus
HSV |
|
what is the seasonal predominance of enteroviral meningitis
|
late summer or fall
|
|
what are the differences in type 1 and type 2 herpes simplex meningitis
|
type 1 is above the diaphram, less severe
more common type 2 below the diaphram, more severe |
|
what are some diagnositic test that can be run to see if a person has tuberculosis meningitis
|
CBC
electrolytes PPD sputum acid fast smear/culture chest radiograph urinalysis none above are usually useful PCR is main use but to use it u must involve infectious disease specialists |
|
what is the CSF profile of tuberculosis meningitis
|
elevated opening pressure
cell count 50-500 usually around 223 lymphocytics predominates late neuts early small protein elevation decreased glucose(slight) |
|
what are the requirements for workup with CSF for tuberculosis meningitis
|
2mls
greater than 10wbc elevated proteins greater than 80mg/dl devoid of blood |
|
what may eosinophilia in CSF is what differential
|
parasitic infection
malignancy MS subarachnoid hemorrhage obstructive hydrocephalus with shunt granulomatous meningitis idiopathic eosinophilic meningitis mycobacterium tuberculossi treponema pallidum(neurosyphilis) mycoplasma pneumoniae fungal rocky mountain spotted fever subacute sclerosiing panencephalitis lymphocytic choriomeningitis virus |
|
what should you think about with granulomatous meningitis
|
fungal or TB
|
|
what are the three forms of fungal meningitis
|
chronic
vasculitis parenchymal invasion |
|
what is the causes of chronic fugnal meningitis
|
cytococcus neoformans(yeast)-most common cause of meningitis in HIV
coccidoides immitis- west coast southwest |
|
what are the main causes of vasculitis fungal meningitis
|
mucor-diabetes* this can kill in 24h
aspergillus- everyone is exposed to this but only immunocomprimised will get infection by it |
|
what are the main causes of parenchymal invasion fungal meningitis
|
candida
cryptococcus neoformans(HIV) |
|
what are the main causes of encephalitis
|
mainly viral
1.HSV 2. Arthropod borne -west nile -east/western equine - st. louis - laCross |
|
what is the main cause of parasitic CNS infection
|
toxoplasma gondii
|
|
how does toxoplasmosis manifest typically in the CNS
|
encephalitis
usually in immunocompromised |
|
what is a characteristic finding that would make you think first about toxoplasmosis?
|
ring enhancing legions
|
|
what are some exposures that lead to toxoplasmosis
|
cat litter
can be exposed at any time even before getting AIDs because after getting AIDS latent infection can become active |
|
what are all the common parasitic CNS infections
|
toxoplamsa gondii
cerebral malaria cysticercosis naegleeria fowleri |
|
what causes cerbral malaria?
|
plasmodium falciparum
|
|
what the primary source of cysticercosis?
|
taenia solium in pork
|
|
how does cysticercosis manifest
|
cyst like lesions everywhere including the brain
|
|
what does naegleeria fowleri cause?
|
meningoencephalitis
also causes eye infections |
|
where is naegleeria fowleri acquired?
|
swimming in warm fresh water during the summer
|
|
what should you think about cause wise with brain abscess
|
anerobic bacteria
|
|
what are the three most common ways that brain abscesses recieve their infectious agent
|
paranasal sinus
trauma hematogenous spread |
|
where are common primary sites for abscesses that may hematogenously spread to the brain
|
endocarditis or lung abscess can throw small blood clots that contain the infectious agents called septic emboli
emboli lodge in capillaries in the brain causing localized hemorrhage |
|
what bugs are most common in immunocompentent patients with brain abscesses
|
staphylococcus aureus
viridans streptococci actinomyces anerobes |
|
what do you expect to cause brain abscesses in immunocomprimised patients
|
aspergillus mucor rhizopus
|
|
what do you expect to cause brain abscess in trauma patients
|
S. aureus. gram neg.
|