Term
| What is a viral encephalitis? |
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Definition
| a viral infection of the brain parenchyma |
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Term
| What is a viral myelitis? |
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Definition
| a viral infection of the spinal cord |
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Term
| What are the most important viral encephalitises/myelitis/meningitis? |
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Definition
| poliomyelitis, rabies, herpes simplex encephalitis, progressive multifocal leukoencephalopathy, subacute sclerosing panencephalitis, CMV, and AIDS encephalopathy |
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Term
| Which type of poilomyelitis virus is most commonly associated with CNS disesae? |
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Definition
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Term
| Which part of the spinal cord is generally spared by polio? |
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Definition
| cervical and lower sacral regions |
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Term
| What is the most characteristic finding of polio in its early stages? |
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Definition
| perivascular infiltrates of neutrophils (after several days to a week, they arereplaced by lymphocytic infiltrate) |
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Term
| T/F Bats can apparently transmit rabies without themselves being infected. |
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Definition
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Term
| T/F Even if the animal is infected, it is rare to get rabies following a mouse or guinea pig bite. |
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Definition
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Term
| What determines the incubation period of rabies? |
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Definition
| the distance from the peripheral nerves at the inital site of infection, and the CNS |
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Term
| Where are the lesions in the first and second form of rabies? |
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Definition
first form: brainstem and cranial nerve ganglia
second form: cortex and gray matter |
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Term
| What are the characteristic findings of rabies encephalitis? |
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Definition
| 1) lymphocytic infiltrates concentrated in the meninges and around parenchymal vessels 2) typical glial nodule 3) negri body- eosinophilic, cytoplasmic inclusion with a basophilic core |
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Term
| Where are the two most common locations for negri bodies? |
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Definition
| hippocampus and purkinje cells in cerebellum |
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Term
| What are the symptoms of herpes encephalitis? |
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Definition
| rapid onset of fever, chills, restlessness, and signs of increased intracranial pressure |
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Term
| What is the mortality rate of herpes encephalitis? |
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Definition
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Term
| What is the characteristic gross appearance of herpes encephalitis? |
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Definition
| edema, hemorrhages and necrosis confined primarily to the temporal lobes. Degree of edema= medial displacement of the uncal gyrus. Can be bilateral or unilateral. Can extend into the cingulate gyrus |
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Term
| What are the findings of acute stage versus later stage herpes encephalitis? |
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Definition
| early: vascular destruction with infiltrates of neutrophils and lymphocytes. Later: glial proliferation |
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Term
| What is the histological feature that characterizes herpes simplex encephalitis? |
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Definition
| eosinophilic intranuclear inclusion bodies (Cawdry type A) in neurons, astrocytes, and oligodendroglia. Charactersistic bull's eye apperance |
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Term
| What types of encephalitises can occur secondary to a measles virus? |
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Definition
| 1) SSPE 2) acute encephalitis with lymphocytic infiltrate in meninges and around vessels with acute rash of measles 3) post measles demyelinating process, autoimmune hyperallergenic phenomenon |
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Term
| What are the symptoms of subacute sclerosing panencephalitis? |
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Definition
| progressive motor and mental deterioration with myoclonus. 1-3 years |
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Term
| What is the frequency and male:female ratio of SSPE? |
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Definition
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Term
| 85% of SSPE arise in ____ environments. |
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Definition
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Term
| What is the gross pathology of SSPE? |
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Definition
| atrophy of cortex, loss of white matter, ventricular enlargement. |
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Term
| What are the histological findings of SSPE? |
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Definition
| eosinophilic intranuclear inclusions with features virtually identical to inclusions found in cases of herpes simplex encephalitis (found in neurons, astrocytes and oligodendroglia) |
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Term
| What are the three contexts in which Cytomegalic inclusion disease (CID) is found? |
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Definition
| 1) treatment induced immunosuppressed adults 2) neonates with widespread infection 3) intrauterine infection with CMV (3rd trimester) |
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Term
| Infants who survive congenital CMV rae left with... |
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Definition
| microcephaly and mental retardation. Grossly periventricular calcium deposites |
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Term
| What is the characteristic histologic appearance of CMV? |
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Definition
| basophilic intranuclear inclusions in neurons. INclusions also found in the adventitial cells of blood vessels |
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