CNS infections Flashcards
what is the number one route of infection for acute meningitis
bloodstream
How doe infections of acute meningitis get into the bloodstream
respiratory tract Skin Intestine direct local extension axonal transport
who usually get bacterial meningitis
children under age of 5
what is the fatality of acute bacterial meningitis
rapidly fatal
what bacteria would cause neonatal acute bacterial meningitis
Group B Strep
Listeria monocytogenes
E. coli
what bacteria would cause children up to 5 years of age acute bacterial meningitis
neisseria meningitidis
haemophilus influenzae B
what bacteria would cause adolescentsacute bacterial meningitis
Neisseria Meningitidis
what bacteria would cause older, debilitaed, immunosuppressed acute bacterial meningitis
listeria monocytogenes
gram-negative Bacilli
what bacteria would cause all ages acute bacterial meningitis
streptococcus pneumoniae
what is the age range for acute viral meningitits
less then 30 years of age
Is acute viral meningitis as fatal as acute bacterial meningitis
viral rarely causes death
talk about Tuberculosis Meningitidis
chronic,
seen as meningoencephalitis
what viruses can cause acute viral meningitis
echovirus
coxsackievirus
what is the gross pathology for bacterial meningitis acute
meninges covered by yellow-white exudate
CSF is cloudy
Under a microscope what cells will be inflamed for the following
- bacterial
- viral
- TB
bacterial: neutrophils
Viral: lymphocytes
TB : neutrophils and Lymphocytes
All: hyperemia; fibrin
how will a patient present with acute meningitis
headache, neck pain, vomiting
what is the Physical exam for acute meningitis
NECK STIFFNESS, Kernig Sign
what is the prognosis for acute bacterial, viral, TB meningitis
Bacterial: risk of death
Viral: self-limited
TB: slow progression; SEVERE: fatal outcome if not treated
What is Waterhouse-Friderichsen syndrome
meningitis-associated speticemia
how does Waterhouse-Friderichsen syndrome impact other organs
hemorrhagic infarction of adrenal glands
Waterhouse-Friderichsen syndrome is most common with what type of acute meningitis
meningococcal
pneumococcal meningitis
How does one main diagnose technique for acute meningitis
lumbar puncture to obtain CSF
what is the protein and glucose level in acute bacterial meningitis
increase protein
decrease glucose
what is the protein and glucose level in acute viral meningitis
protein: little elevated
glucose: normal
what is the protein and glucose level in acute TB meningitis
protein: increased more than bacterial
glucose: decreased
how is bacterial acute meningitis treated
antibiotics as soon as possible
-lumbar puncture within 30 min
how is viral acute meningitis treated
supportive
what do infections of brain parenchyma look like
pus: liquefied brain and PMN’s
mass lesion
what can cause brain parenchyma
bacteria (strep, staph, anaerobes)
what happens to the adjacent brain in brain parenchyma
vasogenic edema
what are the most common lobes for parenchyma
frontal and parietal
cerebellum
what can brain parenchyma cause
increased ICP
how can a neurologist figure out where the brain parenchyma is located
location determines focal neurologic signs
what happens when Brain parenchyma goes untreated
death by increased ICP or rupture into ventricles
how does a doctor confirm brain parenchyma in the office
CT scan or MRI
what is the CSF like in brain parenchyma
normal or increased WBC and protein
glucose normal
what should you not do in the office in order to diagnose a brain parenchyma and why?
lumbar puncture- risk of herniation
how does the doctor treat brain parenchyma
- surgical evacuation
- antibiotics
what is subdural empyema
collection of pus in subdural space
what causes subdural empyema
bacterial or fungal infection of skull bones or air sinuses
what does subdural empyema cause in the brain
thrombophlebitis of bridging veins, occlusions, infarction
what are symptoms of someone who has subdural empyema
early fever, HA, neck stiffness
Late: focal neurologic signs
treatment for subdural empyema
surgery
antibiotics
on a macroscopic level what happens in chronic bacterial meningoencephalitis
fibrinous exudate in subarachnoid space at base of brain, entrap cranial nerves
- hydrocephalus by blocking outlet of 4th ventricle
what are symptoms for chronic meningoencephalitis
headache, malaise, confusion, vomiting, low grade fever
how does the doctor diagnose chronic meningeoncephalitis
lumbar puncture
-acid-fast, mycobacterial culture
how does the doctor treat chronic meningeoncephalitis
antibiotics
what are complications that arise from chronic meningoencephalitis
arachnoid fibrosis
- obliterative endarteritis –> arterial occlusion –> infarction
what are symptoms for chronic meningoecephalitis (lyme disease)
variable: facial nerve palsies, encephalopathy
what would chronic meningoencephalitis look like under a microscope
microglial nodules
scattered borrelia burgdoferi
what does viral meningoencephalitis is what
infection of brain parenchyma with associated meningeal inflammation with or without spinal cord involvement
tropism
certain viruses infect certain cells or certain areas of brain
how does one usually get viral meningoencephalitis
blood-borne
how does viral meningoencephalitis effect the brain
perivascular lymphocytic cuffing, infiltration by other monocytes
what are clinical symptoms for viral meningoecephalitis
fever, HA, brain dysfunction: acute onset
how can a doctor diagnose viral meningoencephalitis
clinical picture
what is the treatment for viral mineingoencephalitis
supportive
- high dose steroids for cerebral edema
what type of viruses cause what type of cases for viral meningoencephalitis
arboviruses causes epidemic cases
what is the CSF for viral meningoencephalitis
pmns then lymphocytes
- elevated proteins
- normal glucose
what is the histology for viral meningoencephalitis
perivascular lymphocytic cuffing,
necrosis with neuronophagia
- microglial nodules
what are the 2 groups involved in viral meningoencephalitis and what virus causes them
- children and young adults (HSV-1)
- neonatal (HSV-2)
where on the brain does viral meningoencephalitis occur HSV
temporal and inferior frontal lobe
orbital gyri
what does viral meningoencephalitis do to the brain HSV
necrotizing, hemorrhagic encephalitis
what is seen microscopally for viral meningoencephalitis HSV
intranuclear cowdry A inclusions
HOw does one diagnose viral meningoencephalitis HSV
PCR to identify virus
brain biopsy
how does one treat viral meningoencephalitis HSV
if early give anti-viral agents
