Flashcards in infections of CNS - viral encephalitis and atypical conventional viral infections Deck (28)
hallmark symptoms of encephalitis in addition to headache and fever
- brain dysfunction including...
- depressed levels of consciousness
- behavior changes
- focal neurologic signs
6 major causes of viral encephalitis
4) herpes virus
5) pox virus
how is specific cause of viral encephalitis determined
- symptoms tend to all be the same so must use PCR, antigen detection etc.
which type of viral encephalitis is usually epidemic?
arbovirus (arthropod borne)
what is the most common non epidemic form of viral encephalitis?
herpes encephalitis caused by hsv-1 or hsv-2?
HSE portal of entry
- nasal mucosa
- trigeminal ganglion
HSE where in the brain?
orbitofrontal and anteromedial temporal cortices
- inflammation, edema, necrosis, hemorrhage
HSE neurological symptoms
- personality changes
- memory loss
- loss of smell and olfactory hallucinations
- hemiparesis or aphasia are possible if unilateral
HSE lab findings
CT - may show focal abnormality
MRI - may see changes sooner, but none specific to HSE
EEG - bitemporal slowing and sharp activity
PCR - most accurate and reliable
treatment of HSE
- treat while waiting for PCR results
- acyclovir, start ASAP, benign medication
most common arboviruses in US
- eastern and western equine
- St. Louis
- West Nile
arbovirus incubation period
2-18 days after mosquito bite
seasonal incidence of arbovirus
late summer, early autumn
rabies incubation period
up to one year
parts of brain rabies tends to attack
- limbic system
- hypothalamic area
- brain stem nuclei
neurological signs of rabies encephalitis
- agitated delirium
- painful spasms of throat musculature
treatment of rabies encephalitis
- no treatment after neurological damage is done
- there is early immune treatment
west nile and polio similarity
- both can attack motor neurons of spinal cord and brain stem
what is the primary difference between the atypical viral infections and the typical acute viral infections?
they cause subacute or chronic disease often after long latent period
subacute sclerosing panencephalitis (SSPE) affects mainly whom?
children and adolescents
SSPE disease progression
1) mental deterioration
2) myoclonic jerks
3) progressive pyramidal and extrapyramidal involvement
4) death within a few years
- high gamma globulin
- high measles antibody titer
who gets progressive multifocal leukoencephalopathy (PML)?
- the debilitated, mostly lymphoma and AIDS
cause of PML
two different papovaviruses (one of which is JC virus)
- small areas of demyelination
- inclusion bodies seen in oligodendroglia