SAH VS Meningitis Flashcards
Why do systemic complications occur in the case of a SAH?
Why does cerebral oedema occur?
Why does delayed cerebral ischaemia occur?
Ischaemia to the brainstem leads to activation of the sympathetic system
Vast cytokine release causes vasodilation throughout the cerebrum
Vasoconstriction and vasospasm leading to ischaemia
Give 3 conditions which are risk factors for SAH.
Marfan
Neurofibromatosis
PKD
Name the 3 most common sites for intracranial saccular aneurysms.
Anterior communicating a
Posterior communicating a
Middle cerebral a
Name the common causative organisms for meningitis in neonates, children and the elderly.
E. Coli
Strep agalactiae
Listeria
Haemophilus influenzae
Neisseria meningitidis
Strep pneumonia
Listeria
How do you distinguish between SP and viridans strep?
Pyogenes and agalactiae?
Optochin sensitive = SP
Bacitracin sensitive = pyogenes
Give some riskfactors for meningitis.
CSF defects Spinal procedures Endocarditis Splenectomy Crowded housing Diabetes Alcoholism
What is the technique to carry out lumbar puncture?
Top of iliac crests posteriorly marks L4-L5 level
Insert needle between spinous processes
Why do you get hydrocephalus in meningitis?
Why do you get vasogenic edema ?
Subarachnoid space inflammation leads to increased resistance to CSF outflow.
Endothelial injury leading to increased BBB permeability.
What is a normal lumbar puncture opening pressure?
8-18mmHg
What is the treatment fo SAH.
Give some complications.
Decompression surgery
Coiling/ clipping anuerysm
IV Fluids - 3L/day
Nimodipine
Death, rebleed, hydrocephalus, seizure, cerebral Ischaemia
If viral meningitis what Tx should be given for herpes and CMV.
herpes - acyclovir
CMV - ganciclovir
Medical Tx for meningitis.
IV ceftriaxone
Dexamethasone (prevent hearing loss)
What is Waterhouse fredrickson sydrome?
Complication of NM as a result of adrenal gland failure
Give some complications of meningitis.
DIC Coma Cerebral oedema Death SIADH Seizures Hearing loss Intellectual deficits Hydrocephalus Focal paralysis
What is the difference in T1 vs T2 weighted scans?
Why does galadonium enhance lesions of head MRIs?
T1 - white matter = lightwhite
CSF - dark
Cortex - grey
T2 - white matter = darker gray
CSF - bright white
Cortex -lighter grey
Angiogenesis around tumour disrupts the BBB allowing for Gd to cross into it
