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Flashcards in CNS infections Deck (57):

progressive multifocal leukoencephalopathy. prgression, MRI T1, T2, sx, caused by, tx

slowly progressive demyelination of CNS in HIV
MRI: confluent WM T2 hyper intensity without mass effect through most of brain. dark on T 1. confusoin, ataxia, weakness. pathetic speaking less. cause by JC virus in HIV. Dx: JC virus in CSF via PCR. tx: HAART therapy and reconstituing immune system. can be caused by Natalizumb (tysabri=used to tx MS)


JC virus

infect oligodendrocyte.



MS tx. can cause PML. RF for PML- prior exposure to JC virus- ab test. 2) prior immunosuppression 3) # of tysabri infusion



caused by toxoplasma gondii. cats. mom to fetus or eat infected meat. 1st few weeks= mild flu like illness. rarely cause sx in healthy. eccentric target on MRI


AIDS + ring enchancement DD

tocoplasmosis v primary CNS lymphoma. can't dd by clinical or image. test for ab (igG) to toxo- but bc many ppl have, only good if neg. test CSF for EBV PCR is sensitive and specific for CNS lymphoma. CT: toco-usualy hypotenuse. lymphoma-hyperdense bc incr cellularity. Thallium taken up by neoplasm not infectious process in SPECT scan


toxo tx

if suspect- empirically tx with sulfadiazine and pyrimethamine (or folinic acid +trimethoprim/ sulfamethoxazole?). if no improve, biopsy. 90% respond. conti 6mo or until no enhancement on MRI


cryptococcus neoforman

yeast -often presnt as lung infection. often immunosupprsed. cryptococcal meningitis -indolent-HA, mental status changes, meningeal signs, low grade fever, stiff neck. LP show high WBC, incr ICP. papilledema. india ink stain show enhanced circles. cryptococcal antigen via latex agglutination test is pos in CSF in 95% of cases. tx: IV amphotericin then fluconazole for 3mo after CSF is sterilized


neuro sx in HIV

10% HIV pit have neuro complaint at dx. myopathy(HIV or med- AZT), neuropathy (chronic, painful, distal polyneuropathy- can be due to meds), myelopathy (~ B12 def), meningitis, dementia, eye disease (retains due to CMV- lumbar radiculutis), stroke (due to HIV vasculitis)


HIV opportunistic infection

CMV, PML, toxo, cryptococcus.


HIV neuro complication stage 1

CD4>500: HIV meningitis, acute inflame demyelinating syndrome


HIV neuro complication stage 2

200-500. dementia, mononeuritis multiplex, myopathy, neuropathy


HIV neuro complication late

<200. toxo, PML, primary CNS lymphoma, cryptococcus meningitis, HIV vacuolar myelopahty, CMV ventriculitis, VZV vasculitis


HSV encephalitis

due to reactivation of latent virus within trigeminal ganglion. most common sporadic encephalitis in the US. present nonspecifically with fever, HA, confusion, personality changes, olfactory/gustatory hall. rapid onset. or focal seizure and motor disturbances.
often in frontal and temporal lobe with massive swelling (hemorrhage)- risk of uncal herniation.
LP: grossly bloody CSF with incr WBC- mostly lymphocyte, hemorhagic
EEG: periodic lateralized epileptiform discharges(PLEDs)! over temporal lobe
tx: IV acyclovir as soon as dx is suspected.


human T lymphotropic virus type I

cause tropical spastic paraparesis. myelopathy common in caribbean and africa and IV drug users. infect SC


varicella zoster virus

shingers occur from reactivation of varicella infection in DRG. usually in thoracic dermatome or V1 distribution of trigeminal N= zoster ophthalmic. tx: 1 wk of antiviral-acyclovir or valacyclovir. can infect cerebral arteries - stroke. can invade CS- myelopathy. painful vascular rash



infection in utero. encephalitis in immunosuppresed= fatal in few mo. associate with retinitis



encephalitis that leads to pschiatric disturbances followed by seizures and death or fatal paralysis due to infection of SC. biopsy show negri body


anterior horn cell of SC

direct target of polio and west nile.


streptococcus pneumoniae

nucal rigidity, photophobia, phonophobia. LP; normal opening P, high WBC, high neutrophil. gram stain-pos spherical cells.


streptococcus agalactiae

Group b strep. most common cause of bacterial meningitis in neonates. most result from hematogenous spread do bacteria from URT infect to choroid plexus. blood culture reveal causative org in many cases. or bacteria can directly enter subarachnoid space from infections of nasopharynx or dental abscesses.. CSF: leukocytosis, dear glucose, incr protein, incr CSF OP. MRI- meningeal enhancement, cerebral edema. sulcal effacement. may cause hydrocephalus, subdural empyema and infarction. tx as soon as suspect bf LP. 3rd gen cep + amp. corticosteroid to dear morbidity from meningitis, deafness


meningitis workup

blood culture, empirically start broad spectrum antibiotics (3rd generation cephalosporin like cefoxatime/ ceftrioxone, vancomycin). LP next unless focal neurological defeats, papilledema and immunocompromised, hx of CNS disease or altered mental status= get head CT first to rule out other causes of sx. if pt has mass, doing an LP may cause herniation


bacterial meningitis

decr gluose (40-85), elevated openning pressure (50-180), incr protein (15-45) , cloudiness of CSF. prelim neutrophile (PMN). pos culture and gram stain. blood pos culture in 50%. tx when suspect- 3rd gen cephalosporin +ampicillin in neonates and pt >50yo. organisms targeted based on age and situation.


viral meningitis

normal CSF opening pressure, clogs. protein <100- prelim lymphocytic pleocytosis. culture neg. PCR. incr RBC in CSF.


TB meningitis

variable CSF OP. glu<40=low, mod to high protein 50-1000. neutrophil early and then lymphocytes later. pos for AFB


fungal meningitis

variable CSF OP, low flu, mod-high protein, prelim lymphocytes. pos culture


guillain-barre syndrome

normal CSF OP and flu. 100-1000 protein. normal leukocyte. albuminocytologic dissociation


kernig's sign

pos when pain when thigh bent at hip and knee at 90degree. in bacterial meningitis


brudzinski's sign

pos= involuntary lifting of leg when left head off exam table with pt supine.


steroid v bacterial meningitis

dear hearing loss. give bf first dose of antibiotics


pott's disease

lower thoracic or upper lumbar. hematogenous spread of TB.


TB CNS clinical category

meningitis, intracranial tuberculomas, spinal tuberculous arachnoiditis. affect base of brain. wide presentation-fever, malaise, stupor, coma, seizure, often hemiparesis.
tx: 1st line- isoniazid (INH), rifampin dn pyrazinamide for 12mo.


pyridoxine/vit B6

given to TB pt to prevent peripheral neuropathy- stocking-glove neuropathy. can also caused by excess pyridoxine.



often result from direct infection from adj site- sinuses. most common primary infection is pulmonary follow by endocarditis. most multiorg- strep, bactericides, enterobacteriaceae, anaerobic bacteria. in head trauma, staph sp most common. unlike meningitis, often focal neuro deficit. ring enhancement ~ tumor, MS. multi suggest hematogenous spread from systemic source. intense inflam response and edema suggest early in formation . need to biopsy, CSF and culture are of little value. fever and neck pain are not common. no LP bc risk of herniation


argyll robertson pupil

pupil accommodates but don't react to light. pathognomonic for neurosyphilis



treponema pallidum. primary: painless chancre-2-6wk. secondary: flu like, rash on palm and sole, condyloma lata 2-6wk. tertiary- neuropyphilis- 10-30y after infection. may dev gum.



may dev
1) meningitis vasculitis- can cause stroke in MCA.
2) tabes dorsalis- inflm destruction of lumbosacral DRG- loss of sensation and pain in leg and abdomen, damage to posterior column of SC. -widen stance, positive romberg sign. dorsal column atrophy
3) general paresis- encephalitic infection with dementia and psych sx.


neurosyphilis dx

no single good test. nontreponemal test for confirmation. treponema tests for screening. LP -high CSF WBC and oligoclonal bands


treponemal tests

t pallidum particle agglutination test (TP-PA), t pallidum hemagglutinin assay (TPHA) and fluorescent treponemal antibody-absorption (FTA-ABS) test. treponemal enzyme immunoassays and immunochemoluminescence test (EIA). detect specific antibody to T pallidin. reactin in weks and remain for life. do not correlate with disease activity or response to tx.


Nontreponemal test

rapid plasma reading (RPR), venereal disease research laboratory (VDRL). both detect antibodies to cardiolipin- nonspecific markers for syphilis. reactive in wks, and be reactive for mo-y after tx.


neurosyphilis tx

IV or IM penicillin for 14days. blood tests at doubling time starting at 3mo to make sure infection is gone. re-evaluate CSF every 6 mo for 3 y. successful tx= dear lymphocyte and protein and VDRL titer


borrelia burgdorferi- causes, stages

gram neg spirochete. lyme disease. infection stages: 1-acute infection- erythema migrants. 2- within wks- flu like, meningitis, cardiac pathology. 3- mo- sensory neuropathy, subtle cog changes in some.


lyme disease tx

oral doxycycline or if neuro sx- IV cortisone.


taenia solium

seizzure, mexico. pork tape worm. causes cysticerocosis.


naegleria fowleri

brain eating amoeba in warm bodies of fresh water- ponds, hot spring



tania sodium. most common parasitic infection of CNS. common in india and south america. primary cause of acqured epilepsy. fecal oral infection. from eating undercooked pork. cyst in M, brain, eyes.
tx: albendazole and steroids to decr inflam.
cyst can grow in ventricles- most common=4th --> obstruct CSF flow -> hydrocephalus= racemes neurocysticercosis (grape like) --> hunting of ventricular system required.


creutzfeldt-jakob disease

rapid onset dementia -fatal in mo. myoclonus. sporadic 80% of time. some familial form- fatal familial insomnia. startle easily. EEG- periodic biphasic synchronous sharp wave, MRI-bilateral area of incr signal intesty mainly in basal ganglia. can get spongiform degeneration of GM due to neuronal loss- cortical ribboning. ban T2 and diffusion in BG, thalamus and cortical ribbon - double hockey stick. CSF show 14-3-3 protein= not specific.


cysticercosis stages

1) vesicular - thin vesicular wall -viable scolex in middle
2) colloidal stage: thick vesicular wall with degenerating scolex and intense inflam reaction
3) granular stage : thick vesicular wall. degenerated scolex
4) calcified stage- nodules


cysticercosis tx

albendazole kill parasite. glucocorticoid minimize inflame reaction. if intraventricular cyst, may need shunting of ventricular system.


immune reconstitution inflammatory syndrome (IRIS)

massive inflammatory response in pt with HIV with reconstitution of immune system. pt with low CD4 with no prior HAART therapy are at highest risk


HIV dementia due to

direct infection of CNS with HIV. dementia progress over several mo= HIV demential complex (HIVD). likelihood is inversely related to CD4. date feature of infection.


HIVD presentation

personality change, psychomotor retardation, subcortical dementia= can' sustain attention, executive fun abn and slow processing speed. language and memory specific test. some low viral load in serum but high in CSF


HIVD imaging

symmetrical confluent WM hyperintensities wo mass effect or enhancement. sig atrophy.



start HAART



can cause necrotizing vasculitis- present with hemorrhagic abscesses in ependymal region. ~ metastasis. punctate calcification and ring enhancing lesion favor infection. dx confirm by PCR. infarction common bc of necrotizing vasculitis of arteries


stages of abscess formation

1) early cerebrates, 2) late cerbritis- dev of necrotic center 3) early encapsulation 4) late encapsulation. early= sig edema. late- collagen capsule with less cerebrates an edema- wks to mo to form.


abscess tx

empriric tx- vanco, metronidazole, 3rd gen cephalosporin for 6-8wks. antibiotics most effective given prior to encapsulation. surgical drainage when large or near ventricles to prevent rupture into ventricle. clinical improvement precede radiographic improvement



hematogenous spread from systemic source. most commonly affect basal meninges and present with cranial neuropathies- abducens N and altered mental status. seizure, vasculatitis w subset infarction, hydrocephalus, focal neuro deficit. tuberculoma.