CNS Infections Flashcards
Anatomic distribution of CNS infections?
- encephalitis
- meningitis
- myelitis
- plexitis/neuritis
Acute bacterial meningitis symptoms?
- 95% have at least 2 of:
-fever
-HA
-stiff neck
-altered mental status
(only 44% have 3 of them) - 20% coma
- 30% seizures
- Rash, otitis/sinusitis, cranial nerve palsies: increased ICP, infection, endarteritis of vasa nervorum.
What bug do you think of if acute bacterial meningitis is accompanied by a rash?
N. meningitis
LP findings in acute bacterial meningitis?
- Elevated opening pressure (>18cmH2O)
- Low Glucose (60%).
- CSF to serum glucose ration 220mg/dL
- Elevated Cell Count: >2000cells/uL
- PMNs >1180cells.uL or (>90% of total cell count).
Do Abx change LP results?
Not significantly
CSF studies?
- culture/stain
- PCR: enterovirus, west nile, HSV1&2
Empiric treatment when suspect acute bacterial meningitis?
-Ampicillin
-Ceftriaxone
-Vanco-
-Acyclovir
Also: corticosterioids
Acute bacterial meningitis bugs and treatment in neonates?
Bugs: 1. Group B Strep 2. E.coli 3. Listeria 4. S. pneumoniae Treatment: Ampicillin+Cefotaxime
Acute bacterial meningitis bugs and treatment in nosocomial infections?
Bugs:
1. Gram (-) Bacilli
2. Staph
Treatment: Vanco+Ceftazedime
Acute bacterial meningitis bugs and treatment if seizures?
Bug: HSV1
Treatment: Acyclovir
Acute bacterial meningitis due to S. Pneumoniae is associated with?
- Otitis media
- Skull fracture
- Alcohol
- Sickle Cell
- Pneumovax immunocompromised/asplenia
Acute bacterial meningitis due to N. meningitidis is associated with?
- Dorms
- Military
- vaccinate students, military, complement deficient, asplenia ppl.
Acute bacterial meningitis due to L. monocytogens is associated with?
- Pregnancy
2. Transplant
Mortality of acute bacterial meningitis?
Kids: 9.4%
Adults: 20%
Viral meningoencephalitis symptoms?
- HA in both
- In encephalitis > meningitis:
- Altered mental status,
- Seizures, EEG abnormalities
- CSF RBCs
- focal signs
- fever, malaise
- In meningitis> encephalitis
- CSF pleocytosis (increased cell count)
- Neck stiffness
Viral meningoencephalitis pathogens?
- Enterovirus: Echovirus, Coxsackievirus
- HSV1 - acute and severe encephalitis
- HSV2 - Mollaret Meningitis (benign recurrent lymphocytic meningitis)
- Arbovirus (West Nile)
- Rabies
- HIV
Viral meningoencephalitis pathogen most likely in summer?
Arbovirus - West Nile
Viral meningoencephalitis pathogens most likely in Fall?
Enterovirus:
- echovirus
- cocksavievirus
Viral meningoencephalitis pathogens most associated with animal exposure?
Rabies
Arbovirus - West Nile, St. Louis Encephalitis,….
Viral meningoencephalitis pathogens most associated with Aphasia or Temporal lobe seizures?
HSV1»_space;> HSV2
Viral meningoencephalitis pathogens most associated with LMN weakness?
Enterovirus
West Nile
Viral meningoencephalitis pathogens most Temporal lobe hemmorhage?
HSV
Viral meningoencephalitis pathogens most Basal Ganglia on imaging?
West Nile
HSV1 encephalitis symptoms?
10% of encephalitis in US 70% mort if untreated 97% permanent neurologic deficit Symptoms: Seizures, Aphasia, Hemiparesis/Motor weakness Audtory/Olfactory/Visual Hallucinations
HSV1 encephalitis workup?
- EEG - temporal sharp waves
- MRI - normal early, then edema/hemorrhage into temporal/orbitofrontal lobes
- CSF/PCR: 5% false negative
Treatment of HSV1 encephalitis?
High dose Acyclovir for 21 days
HSV2 commonly causes meningitis. What are symptoms?
Parathesias
Urinary retention
Transverse Myelitis
Genital lesions predating the CNS symptoms by 1wk.
HSV2 diagnosis? Treatment?
CSF-PCR: 95% sensitivity, 100% specificity.
Acyclovir shortens course.
Benign Recurrent “Aseptic” Meningitis?
= Mollarett Meningitis
-Female, 3-9 attacks/yr, 23% history of genital herpes.
Arboviruses?
Arthropod born:
- West Nile
- St. Louis Encephalitis
- California Encephalitis
- Eastern Equine Viruses.
West Nile Virus anatomically? Risk Factors? CSF? Treatment? Symptoms?
- Acute Flaccid Paralysis: Poliomyelitis like, Asymmetric weakness
- Myelitis
- Meningoencephalitis: brainstem, movement disorder
Risk Factors:
>50yo, summer
CSF- prolonged PMN predominance
Treatment: supportive
Symptoms: 80% assymp, 50% rash, 10% flu, 1% have CNS infection.
Rabies Encephalitis
Hallucinations, agitation, paralysis, hypersalivation, hydrophobia.
Path: Negri Bodies: cytoplasmic eosinophilic inclusions.
HIV Associated Dementia
Minimal imaging changes - hypodense T1 white matter changes.
Risks: Low CD4, high HIV RNA, anemia, HCV.
Responds to anti-retrovirals.
Can cause meningitis, rarely encephalitis.
Lyme disease
Borrelia burgdorferi
Early: lyphocytic meningitis, erythema migrans, facial diplegia, painful radiculitis, optic nneuritis, mononeuritis multiplex, GBS.
Late: encephalomyelitis, - mimics MS, peripheral neuropathy, polyarthritis, cardiac conduction block Type III.
Dx: cerum and CSF Ab.
Fungal meningitis CSF findings:
Low glucose
High Protein
Found in soil and bird excrement and causes fungal meningitis with what symptoms:
CSF finding? Dx with? Tx with?
Cryptococcys neoformans. Elevates ICP -> HA. CSF: mononuclear pleocytosis Dx: India Ink Tx: Amphotericin B
Causes fungal meningitis and focal infections. CSF is significant for lymphocytic pleocytosis:
Dx?
Aspergillosis.
Dx: CSF-PCR
Found in Mississippi and Ohio River Valleys, causes fungal meningitis:
CSF findings? Dx?
Histoplasmosis, Blastomycosis.
CSF: Histoplasmosis: mononuclear pleocytosis.
Blastomycosis: Early PMN–> lymphocytic
Dx: urine polysaccharide Ag
Found in Southwest US, causes fungal meningitis:
CSF findings? Dx?
Coccidiomycosis.
CSF: Early - PMN –> lymphocitic.
Dx: compliment-fixation Ab testing.
Mycobacteria TB:
1% with neuro dz.
Parameningeal infection. Hematogenous spread via lungs, tumbercle formation.
Pott Disease: TB osteomyelitis with paravertebral abscess.
TB meningitis: AFB smear of CSF - low sensitivity. CSF culture - takes weeks. Clinical Dx.
Treponema pallidum
Syphilis. spirochete. Primary - active Secondary - rash Latent Tertiary - gummas, neuro, cardiac. years after primary and 1/3 cases without treatment get tertiary.
Nuero: meningitis, encephalitis, tabes dorsalis, Argyll Robertson pupil
Organisms in abscess for immunocompetent ppl:
S. aureus
Enterobacteriaceae
Organisms in abscess for immunocompromised ppl:
Listeria monocytogenes
Nocardia
Toxoplasma gondii
Abcess on imaging? Tx?
Multiple ring enhanving lesions with surrounding edema.
Tx: Metronidazole and Penicillin
Cephalosporin
Surgery
Most common cause of epilepsy world wide?
Neurocystercosis. Taenia solium. Ingested eggs excreted in animal feces, larvae travels to brain and muscles. From eating raw pork too.
Most common neuroinfections in transplant patinents:
- Aspergillus - septate hyphae branched at 45 degress.
- CMV
- Cryptococcus
- Nocardia asteroides
- Toxoplasmosis
Trearing neurocystercercosis
Calcified cysts are inactive - treat seizures with anticonvulsants.
Active infection: albedazle, praziquantel
CNS Malaria?
Plasmodium falciparum.
Symptoms: HA, maylgia, seizures, later get cerebral edema –>stupor, coma. Mortality 20-50%
3 prion diseases? Symptoms?
- Creutzfeldt-Jakob Disease
- Fatal Familial Insomnia
- Kuru
Psychiatric, rapid onset dementia, ataxia, myoclonus, insomnia