cns infections Flashcards
lumbar puncture indications [3]
- cns infection
- thunderclap headache: rule out SAH when CT/MRI is normal
- evaluate for normal pressure hydrocephalus
lumbar puncture contraindications [3]
- infection near puncture site
- presence of space occupying lesion
- PLT <80, INR >1.4
opening pressure for lumbar puncture
10-18 cm H20
elevated opening pressure for lumbar puncture indicates:
[3]
infective: bacteria, TB, fungal
hydrocephalus
benign intracranial hypertension
low opening pressure for lumbar puncture indicates [2]
blockage (spinal block but high ICP)
intracranial hypotension
yellow CSF indicates [3]
blood breakdown products
hyperbilirubinemia
high proteins/RBC
orange CSF indicates [2]
blood breakdown products
high carotenoid ingestion
pink CSF indicates
blood breakdown products
green CSF indicates
purulent CSF
hyperbilirubinemia
CSF characteristics for bacterial meningitis
opening pressure: elevated
WBC: > 1,000
cell differential: neutrophils, eosinophils, basophils
protein: mild to marked elevation
glucose: normal to marked decrease
CSF characteristics for viral meningitis
opening pressure: normal
WBC: <1,000
cell: LYMPHOCYTE
protein: normal to elevated
glucose: normal
CSF characteristics for fungal meningitis
opening pressure: variable
WBC: variable
cell: LYMPHOCYTE
protein: ELEVATED
glucose: low
CSF characteristics for tubercular meningitis
opening pressure: variable
WBC: variable
cell: LYMPHOCYTE
protein: ELEVATED
glucose: low
brain abscess treatment
drainage/excision
IV abx
types of encephalitis [4]
- herpes simplex
- varicella zoster
- cytomegalovirus
- japanese encephalitis virus
herpes simplex encephalitis symptoms [3]
fever
chills
signs of increased ICP
pathology of herpes simplex encephalitis
oedema > haemorrhage > necrosis of TEMPORAL lobe
herpes simplex encephalitis symptoms [4]
- behaviour & personality change
- focal neurological signs (aphasia, hemiplegia)
- seizures
- drowsiness & coma
japanese encephalitis risk factors [2]
rural residents in padi fields
rural area during transmission period
is vaccine available for japanese encephalitis
yes
dx investigations for encephalitis [3]
CT: exclude mass lesion, localise site of lesion
lumbar puncture
EEG (slow waves for HSV)
encephalitis treatment [3]
anticonvulsants
decrease ICP > mannitol/dexamethasone
antivirals
encephalitis prognosis
poor prognosis
- residual epilepsy / cogimpairment
- 10-30% mortality
meningitis definition
inflammation of meninges around brain & spinal cord, irritation of nerves passing through meninges
s&s meningitis [9]
- fever
- headache
- irritability
- delirium
- LOC
- purpura
- neck stiffnes
- kernig’s sign
- brudzinski’s sign
what is kernig’s sign
trying to extend flexed knee with hips flexed –> hamstring spasm
what is brudzinski’s sign
severe neck stiffness –> hips & knees flex when neck is flexed
meningitis causative bacteria [3]
strep pneumoniae
haemophilus influenzae
meningococcus
meningitis features [5]
purulent exudates, thrombosed veins on surface & base of brain
haemorrhagic infarction of penetrating vessels
neutrophils in subarachnoid space
haemorrhages throughout body
adrenal haemorrhagic necrosis
tuberculosis meningitis features (2)
- small yellow nodules (tubers) on brain surface
- lymphocytes, langhan’s giant cells on histology
viral meningitis causative organisms [3]
mumps
measles
echoviruses
viral meningitis features
dense lymphocytic infiltration
csf shows lymphocytes
lymphocytes in csf indicate what kind of meningitis
viral meningitis
langhan’s giant cells on histology indicate what kind of meningitis
TB meningitis
encephalitis vs meningitis
encephalitis is usually caused by viruses. encephalitis: inflammation of brain
meningitis: inflammation of meninges & spinal cord
dx investigations for meningitis [3]
CT
lumbar puncture
blood culture
meningitis treatment [4]
IV abx
supportive meaures
contact tracing (meningococcal > rifampicin prophylaxis)
vaccination
meningitis complications [3]
cerebral nerve palsies d/t fibrosis
hydrocephalus (block aqueduct)
cortical atrophy (vessel thrombosis > increase ICP)
- mental retardation, blindness, deafness, paralysis
