Neurotrauma Flashcards
What is a TIA?
Transient ischaemic attack - mini-stroke where there is a temporary occlusion of blood supply to the brain. Symptoms resolve within 24 hours.
What is the difference between a cerebrovascular accident and a transient ischaemic attack?
In a TIA symptoms resolve within 24 hours, in a CVA, symptoms persist longer than 24 hours.
What is a stroke?
When part of the blood supply to the brain is cut off, mostly caused by either ischaemia or haemorrhage.
Can a CT head detect a stroke?
Can detect a haemorrhagic stroke but not an ischaemic stroke - its purpose is to rule out a haemorrhagic stroke.
Name some symptoms of an anterior cerebral artery infarct.
- unilateral contralateral motor weakness and sensory deficit in lower limb and shoulder
- urinary incontinence
- aphasia
- corpus callosum involvement
Name some symptoms you would get with a middle cerebral artery infarct.
- contralateral hemiparesis
- contralateral sensory loss
- homonymous hemianopia or quadrantonopia
- aphasia
Can you get aphasia in an infarct of the lenticulostriate arteries?
No, as the cortex is not affected so you don’t get any higher cortical dysfunction.
Name some symptoms of a posterior cerebral infarct.
-contralateral homonymous hemianopia with macula sparing
What is TACS?
Total anterior circulation stroke.
What is PACS?
Partial anterior circulation stroke.
What is POCS
Posterior circulation stroke.
What is LACS?
Lacunar syndrome/lacunar infarct.
What is the equation for cerebral perfusion pressure?
Cerebral perfusion pressure = mean arterial pressure - intracranial pressure.
What is Cushing’s reflex?
Occurs in response to raised ICP - consists of:
- raised BP
- bradycardia
- irregular breathing (slows/stops)
What is a Cushing’s ulcer?
Occurs as a result of Cushing’s reflex. The parasympathetics that cause bradycardia also causes increased gastric acid production.
Why do you get bradycardia and irregular breathing in Cushing’s triad?
Compression of the cardiovascular and respiratory centres in the medulla/brainstem.
What is the monro-Kellie doctrine theory?
ICP is made up of arterial volume, venous volume, brain and CSF. This theory states that if one component increases in volume, one of the other components must decrease in volume to maintain a normal ICP.
Name some red flag symptoms for raised ICP.
Headache
Vomiting
Visual problems
They are especially more concerning if present in the morning.
What is idiopathic intracranial hypertension and how is it diagnosed?
Benign intracranial hypertension that is more common in middle aged women. Pathology is not known but condition improves with weight loss and BP control. For diagnosis, need to do a lumbar puncture to measure CSF pressure.
What is an ICP bolt?
When you drill a hole in the skull and attach a monitor to monitor ICP - allows you to see changes in ICP before Cushing’s reflex escalates and MAP increases.
What drug can be given to treat raised ICP?
Mannitol - sugary substance that increases osmolarity of blood and draws fluid out of brain across BBB.
What causes the purpuric rash in meningococcal septicaemia?
Microvascular thrombosis due to increased clotting, decreased levels of proteins C + S (natural anticoagulants that inhibit clotting), and impaired fibrinolysis.
When doing a lumbar puncture, in which compartment do you want to the needle to be in?
The sub-arachnoid space, as this is where the CSF is.
How would you do a lumbar puncture?
Locate the iliac crests (they are an anatomical marker of L4/L5 level. Insert the needle between the spinous processes at this level. Feel the give of ligamentum flavum, then feel the give of the dura. You should see clear fluid in your needle.
If you did a lumbar puncture when there is raised ICP, what could happen?
Could get herniation of the uncus or brainstem.
What is xanthochromia?
Yellow colouring of CSF due to bilirubin, could indicate a recent SAH.
When doing a lumbar puncture, why should you take multiple bottles of CSF.
The first bottle could contain blood just due to the trauma of the procedure and does not actually indicate a brain bleed.
