ID Flashcards
Acute HIV meningitis
Aseptic meningitis in early HIV infection
aseptic - cognition preserved vs encephalitis
-initial HIV infection during seroconversion
-fever + meningeal signs with alertness preserved
-HIV Ab may not be detected/serology negative early on
-CSF: lymphocytic pleocytosis; normal glucose, mildly increased protein
Tx: no specific therapy; HAART
HIV Dementia
late stages CD4<200
-cog decline + psychomotor dysfxn , tremors, incoordination - rare focal neuro deficit
-subcortical cortex spared
Prevent: HAART
Tx: HAART-simple regimen of drugs b/c demented
primary CNS lymphoma
focal neurologic deficit
-EBV-HIV pt - immunocompetent pts don’t have EBV
Dx: positive EBV CSF ; cytology-atypical cells
Flow cytometry - monoclonal B lymphocytes
MRI: periventricular lesions/callosal lesions that contrast enhancement + mass effect**
Tx: high dose methotrexate + ART
PML
JC virus - polyomavius
-gradual focal neuro deficits
-MRI: nonenhancing coalescing white matter patchy enhancement: parieto-occipital
Dx: JC virus DNA PCR in CSF (-lots of ppl have serum Ab to virus, non specific)
gold standard - biopsy - large oligodendrocytes with intranuclear inclusions ; myelin loss, giant astrocytes
EM: spaghetti and meatballs virus
HIV neuropathy
direct effect of virus, cytokine upregulation, esp as CD4 drop
-distal sensory neuropathy
vs. acute inflammatory demyelinating polyradiculoneuropathy - 2/2 immune system dysregulation- at seroconversion
vs CMV polyradiculomyelitis -areflexia, sphincter dysfxn, leg pain + weakness
HIV myelopathy
in AIDS- spasticity, weakness, no pain, UE spared
lateral, post column demyelination, microvacuolar degeneration
DDx HTLV-1
HIV muscle wasting
-autoimmune myositis - HIV induces MHC1 expression causing muscle fiber injury
-muscle wasting syndrome - AIDS cachexia
-pyomyositis
mitochondrial myopathy -zidovudine
-HIV doesn’t invade muscles
Hypoglycorrhachia
hypoglycorrhachia - low CSF glucose
Neurosarcoid
Lyme disease
Ixodes deer tick carrying Borrelia burgdorferi -spirochete
Stage 1-local infection- Bull’s eye rash - erythema chronicum migrans (not marginatum) - serology negative
- disseminated stage (can test serology but does not rule in/out)
-aseptic meningitis - lymphs + protein, Ab vs Borrelia in CSF
-bilateral Bell’s palsy, other CN palsy
-peripheral neuropathy, mononeuritis multiplex, polyradiculopathy - Persistent infection months later - Intermittent migratory arthritis
encephalomyelitis
dementia
axonal polyneuropathies (“straw man with arrow in head”)
Dx: B burgdorferi Ab in CSF + serum
Ab Index - IgG to Borrelia species in the CSF -true intrathecal antibody synthesis, suggesting neuroinvasive Lyme disease
ELISA+ western blot
MRI-leptomeningeal enhancements
Tx: ceftriaxone (doxycycline only if no CSF/cardiac Sx)
aspergillosis
immunocompormised pts-invasive in CNS
-invades blood vessels-strokes
-vasculitis, granulomas, abscesses
Histo: hyphae in blood vessels - septate hyphae branching at acute angles (corn field plant with acute angles)
Cryptococcus neoformans
encapsulated yeast
-HIV CD4<100, rare immunocompetent
meningoencephalitis confusion
MRI-hydrocephalus, pseudocysts, cryptococcomas, infarcts
CSF: high OP, high protein - yeast and capsules gunk up CSF
Dx: crypto CSF Antigen
India ink smear- encapsulated halos-not sensitive
biopsy: budding yeast near blood vessels (double buds); soap bubbles
Tx: Flute player, frogs, and pine cone - ampho B + flucytosine, then
fluconazole for long term maintenance
Tx increased ICP b/c increase mortality -> CSF drainage
Toxoplasmosis
Protozoa
-can get from raw meat, water or oocytes in poop of cats (kitty litter box)
-acquire earlier; reactivate when HIV CD4<100 (cat with $100 bill)
Sx: seizures, focal deficits
MRI: ring enhancing lesions; eccentric target sign
Tx: Sulfadiazine + pyrimethamine + folinic acid (FOLIAGE)
(sulfa+pyrimethamine affect folate)
sulfa allergy: clindamycin (CLEAN CAT)
prophy: TMP/SMX when CD4<100
biopsy: big round blob - encysted bradyzoite
neurocystercircosis
Tanea soleum
west nile virus
Flavivirus -Hep C, (high C flavor) Dengue, Yellow fever, West Nile
WNV - anterior horn cells - Birds with red feathers on head
(transmitted via mosquitos); encephalitis, meningitis, flaccid paralysis
-summer infection, initial fever then AMS
-nadir 3-8 days
-cranial neuropathies, tremor (flapping bird wings - tremor)
-esp in elderly
Dx: IgM in CSF (PCR less sensitivity but diagnostic)
Mucormycosis -
zygomycosis - mucor, rhizopus, rhizomucor- enter respiratory tract
-right angle branching (tool on wall of car repair)
-necrotizing angioinvasive
-CVST-cavernous sinus sinus
risk: DM, iron chelation with deferoxamine, immunocomp
Tx: ampho B
ampho B: renal failure, hypokalemia + hypomagnesemia (boggy frog low level electrolytes)
Meningitis most common causes
Neonates: Listeria, GBS, E coli + other enteric gram negative bacilli (Klebsiella, salmonella, shigella, pseudomonas, etc)
1 month-23 months: Strep pneumo, Neisseria, Strep Agalctiae, Haemophilus influenza (Tx ceftriaxone; if B- lactamase negative can use ampicillin), E coli
2-50: Strep pneumoniae + Neisseria
>50: Strep pneumo, Neisseria, listeria, aerobic gram negative bacilli
Listeria: only 30% positive gram stain (higher for gram-neg bacilli)
Post NSGY: pseudominas, Staph, propionibacterium acnes (NOT strep pneumo for hospital acquired meningitis)
TB
Pott’s disease-thoracic spine
-hematogenous spread to anterior vertebral bodies
-kyphosis, scoliosis
Meningitis - base of brain- cranial neuropathies b/c brainstem
MRI: meningeal enhancement
CSF: high protein, low glucose, OP elevated
PCR more sensitive; acid fast smear and CSF cultures low sensitivity
Tx: 4 drugs x 2 months, then 2 drugs
Tuberculomas - space occupying
Peripheral neuropathy is M leprae
Leprosy
Mycobacterium leprae - spreads via resp tract but no resp Sx (Hasen disease)
-tropism for cool areas of body; Schwann cells
Lepromatous variant - cellular immunity compromised pts - spread to skin + nerves->maculopapular rash+nodules; sensory loss over coolest regions of body-pinna of ears, dorsum hands/feet
Tuberculoid variant - normal immunity pts - asymmetric peripheral neuropathies + thickened nerves, less localized lesions
-demarcated hypopigmented lesions
-delayed hypersensitivity rxn, not direct invasion vs. lepromatous variant
ulnar N-Claw hand -(DDx mononeuritis multiplex)- foot drop
Dx: biopsy-granulomas + acid fast
Tx: rifampin, dapsone, clofazimine (Deputy Dapson with rifampin riffle and cloth clofazimine)
Brain abscesses
Before abscess ->cerebritis - poorly defined irregular lesion, hyperintense on T2
Polymicrobial - spread via contiguous infection or hematogenous
-focal neuro Sx
MRI: ring enhancing lesions, edema
1st - cerebritis -> central necrosis -> capsule formation
Tx: drain + ABx IV 6-8 wks
Syphilis
primary - painless chancre
secondary syphilis - 2-12 weeks-dissemination - meningitis, cranial neuropathies
tertiary syphilis - aortitis, gummas,
tabes dorsalis -myelopathy+arelfexia, ataxia, loss pain/temp ->Charcot joints-
meningovascular syphilis - after years of infection - stroke in arterial distribution b/c vasculitis, endarteritis obliterans
parenchymatous syphilis - general paresis - dementia, neuropsych manifestations, pupil problems, speech problems
Dx: late forms of neurosyphilis - serum treponemal tests should always be performed.
-reactive CSF-VDRL establishes the diagnosis of neurosyphilis but can be falsely negative
Tx: penicillin G; f/u CSF for response to therapy
Whipple disease
Tropheryma whippelii
-EOM abnormalities, oculomasticatory myorhythmia, dementia
-hypopigmentation, adrenal insufficiency
Dx: biopsy GI - PAS + macrophage inclusions
-CSF PCR-T. whippelii
Tx: ceftriaxone then TMP/SMX
CJD
PrPcellular ->PrP scrapie (more B pleated sheets)
MRI: cortical ribbon -restricted diffusion + caudate head restricts
hockey stick sign: hyperintensity caudate head+putamen
pulvinar sign - BL thalami hyperintensity
Familial CJD: AD-PPNP-Chr 20 (twenty twerpy cows)-susceptibility gene
Familial fatal insomnia - sympathetic hyperactivity, HTN, dementia, tremor, myoclonus, insomnia
Gerstmann-Straussler-Scheinker - inherited prion disease over yrs - ataxia, dysarthria, dementia
Dx: CSF- RT-QuIC is the most sensitive and specific CSF diagnostic test for sCJD.
EEG: repetitive sharp wave periodic pattern
biopsy: spongiform
HSV
HSV1-MCC fatal sporadic viral encephalitis
-immediate CNS invasion vs reactivation with recurrent infection or reactivation in situ HSV in brain
MRI - hemorrhagic temporal lobe
Dx: CSF HSV PCR
Tx: IV acyclovir
VS MENINGITIS - HSV-2 (immunocompetent pts)
Measles
Encephalitis
Post viral encephalomyelitis
ADEM
Subacute sclerosing panencephalitis - 2-12 yrs after infection - personality changes; seizures, ataxia, akinetic mutsim, choreoathetoid
-virus maturation in neural cells
EEG: pathognomonic - periodic delta waves on flat background
path: nuclear, cytoplasmic inclusion bodies
Immunocompromised: measles inclusion body encephalitis - 1-6 months after exposure, dementia, seizures, myoclonus, coma
Tania soleum
neurocysticercosis - not from ingestion of pork meat b/c eat tapeworms; get infected from eggs in feces -> larvae penetrate tissues
seizures, hydrocephalus, vasculitic syndrome with strokes
MRI: contrast enhancement + calcifications
-Tx: albendazole - “strong man Al bending a bar” - circus scene
2nd line -Paraziquantal - Pretzel stand
amebic meningoencephalitis
Naegleria fowleri - Niagara falls (others -acanthamaeoba, balamuthia mandrillaris)
-fresh water
-enter through cribiform plate
Acanthamoeba - hematogenous dissemination from corneal infection - contact lenses
path: trophozoites
-purulent meningitis, microabscesses
Frogs – Amphotericin treatment
VZV
Chickenpox primary infection->latent in ganglia
Herpes zoster - thoracic dermatomes
Zoster sine herpete - sensory Sx without rash
Herpes zoster ophthalmicus - ophthalmic division trigeminal N; keratitis-> blindness
Ramsay Hunt - geniculate ganglion facial palsy + rash in external auditory meatus, vertigo; tinnitus
Necrotizing retinitis
VZV vasculopathy: small + large intracranial vessels - immunocompetent pts
-multifocal narrowing
Myelitis
Tx: acyclovir +/- steroids -
Dx: anti-VZV antibodies in CSF; higher yield vs DNA
-negative VZV DNA PCR does not exclude
infective endocarditis
risk mycotic aneurysms - SAH if ruptured - distal bifurcations in vessels (not circle of Willis)
-superficial hemorrhage, no vasospasm
-if SAH during infective endocarditis - Dx: cerebral angiogram for mycotic aneurysms
Rabies
Sx: dysphagia, neck/facial muscle spasms triggered by attempting to drink water -> hydrophobia
-frothing in mouth, increased salivation
-paralytic form - parethesias + weak bitten limb -> quadriplegia
Negri bodies: cytoplasmic eosinophilic inclusions purkinje cells + pyramidal cells of hippocampus
-little black dot perfect circle
-HDCV vaccine after exposure + rabies IG
