Term
| What are the major diseases caused by bacteria, fungi? |
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Definition
| meningitis, cerebritis & cerebral abscess |
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Term
| In what will untreated cerebritis result? |
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Definition
| tissue necrosis and walling of the necrotic area by reactive astrocytes and fibroblasts which form an ABSCESS |
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Term
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Definition
| a space occupying lesnion which can mimick a tumor |
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Term
|
Definition
| bacteria invaded PARENCHYMA and reaction consists of infiltration by PMS, lymphocytes, and macrophages |
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Term
| what usually accompanies cerebritis? |
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Definition
|
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Term
|
Definition
| invasion of SUB Arachnoiid space by bacteria--causing a reaction of infiltrations by polymorphonuclear leucocytes, lymphocytes, and macrophages |
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Term
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Definition
| local collections of inflammatory and reactive cells such as microglia, astrocytes, and macrophages. Found in viral invasions |
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Term
| What precipitates the formation of a glial nodule? |
|
Definition
| a viral invasion of the brain parachyma |
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Term
| what type of encephalitis causes tissue tissue necrosis/abscess formation? |
|
Definition
| never virus--always bacteria |
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Term
| when do nuclear inclusions form? |
|
Definition
| in viral encephalitis, never bacteria |
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Term
|
Definition
| neurons infected by viruses that are phagocytoses by microglia |
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|
Term
| what disease do we see neurophagia in? |
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Definition
|
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Term
| Is phagocytosis of individual cells seen in cerebritis caused by a virus? a bacteria? |
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Definition
|
|
Term
| What is viral meningoencephalitis? |
|
Definition
| viruses that infect the subarachnoid space |
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Term
| What is the major disease caued by viruses in the CNS? |
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Definition
|
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Term
| What is one major feature that helps to explain the varied syndromes associated with viral attacks? |
|
Definition
| viruses often exhibit cellular TROPISMS |
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Term
| What are 2 general ways HIV can cause CNS disease? |
|
Definition
| direct infection of neural tissues and by increasing the host's susceptibility to opportunistic infection |
|
|
Term
| Is spongiform encephalopathy "infectious?" |
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Definition
|
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Term
| what is the only direct route to the CNSS? |
|
Definition
| `Through the olfactory epithelium |
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Term
| What is the most common route of infection? |
|
Definition
| hematogenous spread from other sites |
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Term
| Where are the only lymphatics in the CNS? Why is this important? |
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Definition
| The cNS has no lymphatic system, lymphatics are present in the spinal epidural space. These for a possible route for the production of spinal epidural abscesses from infection of the retropharyngeal or retroperitoneal spaces |
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Term
| In regards to cell speficity, where do poliomyelitis and progressive multifocal leukoencephalopathy specify? |
|
Definition
| anterior horn neurons and oligodendrocytes respectively |
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Term
|
Definition
|
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Term
|
Definition
| within the lateral, third and fourth ventricles |
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|
Term
|
Definition
| in the arachnoid villi along the superior sagitall sinus |
|
|
Term
| What are host factors for increasing the risk of CNS infection? |
|
Definition
| immunodeficiency, diabetes, infections, age, genetic factors |
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Term
|
Definition
| invation of the parachyma by viruses causing selective cell death |
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Term
|
Definition
| invation of parachyma by bacteria, fungi |
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Term
|
Definition
| inflammation of the spinal cord |
|
|
Term
|
Definition
| inflammation of the ventricular system. Most often a result of extension of a meningitis, rupture of an absess, or intro of pathogens by iatrogenic means |
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|
Term
|
Definition
| abscesses occur in the brain parenchyma as evolution of untreated cerebritis. may also occur in potential spaces such as the epidurla space. |
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Term
| What are the most common causes of acute bacterial meningitis? |
|
Definition
| e.coli, h. influenzae, n. meningitides, and pneumococcus |
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|
Term
| HOw do bacteria reach the brain in acute bacterial meningitis? |
|
Definition
| by hematogenous dissemination, following infection of neighboring stuctures |
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|
Term
| What happens when bacteria invade in an acute bacterial meningitis? |
|
Definition
| pus accumulates, along with PMNs |
|
|
Term
| As an acute bacterial meningitis ages, what are the cellular difference? |
|
Definition
| PMNs become less abundant and are replaced with plasma cells, lymphocytes, and macrophages, injesting necrotic debris |
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|
Term
| what is the most common complication of acute meningitis? |
|
Definition
| development of hydrocephalus--this is a result from the prolif of connective tissue in the subarachnoid space leading to fibrosis of the leptomeninges and obliteration of the subarachnoid space |
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|
Term
| what are the most common causes of meningitis? |
|
Definition
| ECHO, coxsackie, herpies, mumps, EBV |
|
|
Term
| Are most viral infections self limiting? |
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Definition
|
|
Term
| what are the major histo features of viral encephalitis? |
|
Definition
| microglial nodules and perivascular lymphocytic infiltrates |
|
|
Term
| What are most common causes of chronic meningitis? |
|
Definition
|
|
Term
| What are pathological changes of chronic meningitis? |
|
Definition
| subarachnoid space opacified due to an exudate (like in acute bacterial meningitis) but these change are greater around the base of the brain |
|
|
Term
| Since there is TB related chronic meningitis, are there granulomas? |
|
Definition
|
|
Term
| what are the major complications of chronic meningitis? |
|
Definition
| hydrocephalus due to the ongoing inflammatory response, and cerebral infarction resulting from inflammation and subsequent obstruction of blood vessels. |
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|
Term
|
Definition
| a circumscribed intraparenchymal mass caused by a TB infection |
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|
Term
|
Definition
| locomotor ataxia--degeneration of te spinal dorsal colums and roots. loose both axons and myelin in dorsal roots. |
|
|
Term
| what are the most common manifestation of Lyme disease? |
|
Definition
| meningitis and cranial neuropathies |
|
|
Term
| what are the direct effect of AIDS? |
|
Definition
| HIV directly infects macrophages and microglia |
|
|
Term
| what are major opportunistic viruses in HIV? |
|
Definition
| cytomegalovirus, cryptoneoformans |
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|
Term
|
Definition
|
|
Term
| What does the JC virus infect (what has been directly proven)? |
|
Definition
|
|
Term
|
Definition
| polypeptide with a similar confimation to native proteins but an alpha helix (normal) has been changed to a beta pleat (abnormal)--confirmational change. Abnormal causes diseases such as creutzfeldt-Jakob Disease (CJD) and Fatal insomnia. |
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Term
| What diseases have prions been implicated in? |
|
Definition
| Diseases such as creutzfeldt-Jakob Disease (CJD) and Fatal insomnia. |
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Term
|
Definition
|
|
Term
| Besides genes, what are 3 ways of getting CJD? |
|
Definition
| contaminated dural grafts, contaminated brain electrodes used for cortical recording, injections of extracts of growth horomone from human pituitary), and blood transfusion. |
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|
Term
| What does the "protein only hypothesis" state? |
|
Definition
| the transmissibility of CJD works because the pathological prion protein serves as a template for the conversion of the normally soluable prion to a proteinase K resistant aggregate of insoluable prion protein which is toxic to the neurons. |
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|
Term
| How do chloropromazine and mepacrine act to prevent prion pathogenisis? |
|
Definition
| They inhibit the invitro conversion of normal prion protein to pathological prion conformations |
|
|
Term
| Who gets most CNS fungal infections? |
|
Definition
|
|
Term
| How are most fungal infections spread to the CNS? |
|
Definition
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