OCC Flashcards
Investigations for SAH
CT head (within 6hrs, sensitivity and specificity is 100%). Fresh blood in the CSF will appear bright
If CT is negative, can do LP to look for xanthochromia. Yellow CSF due to bilirubin breakdown of subarachnoid blood. Reliable up to 12 days after (12hr to 12 day rule!)
Immediate management for SAH
What if symptoms improve? Further investigations and management
Nimodipine= calcium channel blocker
Reduces spasm of the ruptured cerebral artery, preventing ischaemia (i.e. a stroke)
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Bed rest at 30-45 degrees supine
IF improves:
Cerebral angiography to find source of bleed (usually ruptured aneurysm)
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Platinum coil to cause aneurysm to CLOT, SCAR THEN HEAL. Use neuroradiology
Difference between symptoms of epilepsy, stoke and migraine
Epilepsy leads to gain of function (overactivation of brain areas) so flashing lights, muscle convulsions, odd sensations in the skin.
TIAs and strokes are caused by areas of the brain ceasing to function due to a lack of blood (because of an embolism or haemorrhage) and are therefore characterized by ‘negative’, loss of function , symptoms and signs (loss of vision, numbness, loss of power in muscles).
Migraine can produce both negative and positive symptoms.
Differentiate migraine with aura without headache with epilepsy
Seizures often followed by postictal phase where patient is exhausted and confused.
Migraine treatment
5-HT1-agonists (=triptans, e.g. sumatriptain),
analgesics (paracetemol, aspirin)
Antiemetics (metaclopramide)
Metaclopramide MOA
D2 receptor antagonist. Blocks D2 receptors in the chemoreceptor trigger zone in the central nervous system
Treatment of migraine with aura without headache
Same as migraine
Prophylaxis for migraine
Propanolol
Which sinuses are usually affected by sinusitis.
Which are we worried about, why and what management.
Maxillary- usually resolves spontaneously (sometimes needs Abx e.g. amoxicillin)
Frontal sinusitis is dangerous, could erode into brain causing meningitis/abscess. Refer to ENT. Arrange CT head. If either frontal sinuses affected, Abx and frontal sinuses drained (=antral lavage)
What could predispose to sinusitis
Nasal septum deviation
What does it mean if the margins of the optic disc are poorly defined
Suggestive of papilloedema (can indicate raised ICP)
Where are most brain tumours found in children
Posterior fossa (so could lead to headache in occipital region)
Most common brain tumour in children
Medulloblastoma in the cerebellum (so can lead to clumsiness)
Child has brain tumour leading to headache… management
Dexamethason to reduce brain inflammation and improve the headache, then discus surgical options
Differential diagnosis of intracranial tumour
- 90% are secondary
- 10% primary
