Neuropathology Part 3- Neuro Inf. (9) Flashcards
What is meningitis generally
Inflammation of the leptomeninges and sub arachnoid space
what are the 4 types of meningitis
- Acute purulent (bac)
- Acute lymphocytic (viral)
- chronic meningitis
4 chemical meningitis
what are the 2 types of acute meningitis
Acute aseptic (viral( Acute purulent (bac)
Acute aseptic meningitis- what is it, what is it due to, signs
- leptomeningeal inflammation due to virus
- mc is enterovirus
- fever, signs of meningeal irritation, depressed conscious (better overall tho)
Acute purulent menigitis- what is it, s/s
Neutrophilic (bac) infiltration of leptomeniges and superficial cortex w extension into cortical layers
risk of death (worse)
-headache, nuchal rigidity etc
mycobacterial menigoencephalitis- causative agent, where
myobacterial tuberculosis in immunocompramised host
-basal surface of brain (formation of tuberculomas withing the brain and dura mater)
what are the nontuberculous mycobac and how are they transmitted
M. avium, m. Intracellulare
trans- water+soil, no evidence of human to human trans
-risk in immunocomp
CNF findings for prulent (cells, glu, pro, pressure)
cells- up to 90000 neutrophils
glu- decreased <45
pro- Increased >50
pressure- very elevated
Aseptic CNF- cells, glu, pro, pressure
cells- 100-1000 most lymphocytes
glu- normal
pro increased
pressure- slightly elevated
Mycobacterial CNF- cells, glu, pro, pressure
cells- 100-1000 most lymphocytes
glu- decreaed
pro- increased
pressure- mod increase
morphology of acute bacterial meningitis- step pneumonie, h. influenxa, neisseria
strep pneumonie- exudates on cerebral convexities
h. influenzae- basal exudates
neisseria- less exudates
morphology of tb meningitis, cryptocaccal menigitis, acute lymphocytis
tb- thick basilar exudate
cryptococcal- gelatinous slick material in leptomeninges, no exudate
lymphocytic- parenchyma may be edamatous
micropscopic morphology- bacterial, mycobacterial, cryptoccal, viral
bac- neutrophilic infiltrate
mycobacterial- granuomas and giant cells
cyrpto- numerous budding yeasts
viral- lymphocytic infiltate
How does cerebral abscess spread and predisposing conditions
Hematogenous dissemination or direct spread from contigous foci
- Acute bac endocarditis
- cyanotic heart disease
- chronic pulmonary abbsces
How does cerebral abcess appear on MRI and clinical manifestations
CT.MRI- ring enhancing lesion
clinical- signs of increased intracranial pressure, focal neuro deficits
complications of bacterial menigitis
- leptomenigeal adhesions leading to hydrocephalus
- cranial nerve impairment
- coma/death
Viral menigitis complications
usually resolves w no complications
what is encephalitis and what is the usual origin
inflammation of the cerebral parenchyma, which is often viral in origin
Viral encephalitides viral cause examples
arthropod borne Herpes type 1 Rabies HIV Coxsachievirus cytomegalovirus
3 general microscopic mophology features of encephalitis
- microglial nodules
- perivascular lymphocytic cuffing of vessels
- neuronophagia
all leading to neuronal loss
Specific microscopic feature of viral encephalitedes (HSV, HIV, CMV)
HSV- intranuclear inclusions
HIV- Multinucleated giant cells
CMV- Intranuclear (owl eye) inclusions
What is the mc CNS infection in AIDS
CMV encephalitis is mc nervous system inf seen in late stage disease
Morphology of rabies viral encephalitides and where found
Negri bodies- round to oval eosinophilic cytoplasmic inclusions in pyramidal neurons of the hippocampus and purkinje cells of cerebellum
histopathology of HIV and in spine
multinucleated giant cells
spine- vacuolar myelopathy
