Vascular Stroke

Question 1

What is intracerebral hemorrhage?

Answer 1

15% of strokes

bleeding into the brain, putting pressure on areas and blocking pathways

Question 2

What is subarachnoid hemorrhage?

Answer 2

patients often younger
bleeding into the subarachnoid space (usually aneurysm)
extremely severe thunderclap headache
abrupt loss of consciousness
stiffness of neck

Question 3

Where does the anterior circulation go?

Answer 3

internal carotid branches into middle and anterior cerebral arteries.
also supplies blood to the optic nerve and retina

Question 4

Where does the MCA go?

Answer 4

lateral part of the cerebral hemisphere

Question 5

Where does the ACA go?

Answer 5

anterior 3/4 of the medial surface of the cerebral hemisphere

Question 6

Where does the posterior circulation go?

Answer 6

veterbral and basillar arteries provide blood to the brain stem, cerebellum, thalamus and the medial part of the temporal and occipital lobes

Question 7

what are lacunar infarcts?

Answer 7

sub group of ischaemic strokes caused by occlusion of a small penetrating branch of a larger cerebral artery supplying the deep white matter

Question 8

What are the ways atherosclerosis can cause ischameic stroke?

Answer 8

thromboembolism
occlusive thrombus
low flow/inadequete perfusion
haemorrhage into a plaque

Question 9

What blood flow can neurons not survive long at?

Answer 9

<5ml/100g/min

Question 10

What blood flow does metabolic rate of oxygen begin to fall?

Answer 10

20ml/100g/min

Question 11

What blood flow is neuronal cell membrane funciton impaired?

Answer 11

below 10ml/100g/min

Question 12

What are the steps to a neuron dying?

Answer 12

K moves into ECspace
Ca moves into cell compromising mitochondrial function
Na Cl and water enter neurons = swelling
release of ROS
perioxidation of FAs in organelles/membranes
anaerobic glycolysis leads to lactic acid
increased activity of excitatory NTs

Question 13

What is the ischaemic penumbra?

Answer 13

the reduced perfusion of the peripheral zones leads to electrical failure and dysfunction of the neurons.

Question 14

What are the clinical symptoms of a total anterior circulation infarct (TACI)?

Answer 14

ICA or MCA
dysphasia apraxia or agnosia
homonymous visual field defect (optic radiation)
unilateral motor and/or sensory deficit of face/arm/leg

Question 15

What are the clinical symptoms of Partial anterior circulation infarct (PACI)?

Answer 15

ICA MCA or a branch ACA
two of three components of TACI
focal cerebral dysfunction alone
unilateral motor/sensory deficit (isolated hand invovlement)

Question 16

What is isolated homonymous hemianopia usually caused by?

Answer 16

occlusion of a posterior cerebral artery (POCI)

Question 17

What are the clinical symptoms of a posterior circulation infarct (POCI)?

Answer 17

vertebral, basilar or PCA
ipsilateral cranial nerve palsy
contralateral motor/sensory deficit
bilateral sensory/motor deficit
disorder of conjugate eye movement
cerebellar dysfunction
isolated homonymous visual field defect

Question 18

What are the clinical symptoms of a lacunar infarct?

Answer 18

pure motor stroke
pure hemisensory stroke
sysarthia-clumsy hand
ataxic hemiparesis

Question 19

What excludes a lacunar infarct?

Answer 19

abnormal higher cerebral funcitoning
signs of a brainstem abnormality (gaze palsies, crossed deficits)
impaired level of consciousness

Question 20

When does treatment need to occur?

Answer 20

within the first couple hours

Question 21

What are the treatment strategies?

Answer 21

Prevention of clot formation, propagation and embolism
Removing the vascular obstruction bu lysis of the occluding thrombus
Increasing collateral circulation and perfusion of the ischaemic penumbra (not useful)
Increasing the resistance of the brain to ischaemia. (neuroprotective treatment)

Question 22

how is a transient ischaemic attack (TIA) recognized?

Answer 22

sudden onset of focal neurological symptoms over a few seconds or minutes that persist for less than 24horus

Question 23

What is a TIA?

Answer 23

due to focal interruption of the blood supply to the brain

indicate a risk of stroke

Question 24

How do we prevent ischaemic stoke?

Answer 24

Modifying risk factors, lower BP etc
Anticoagulants
Carotid endarterectomy (for patients with stenosis)
Anti-platelet madications

Question 25

What are the causes of intracerebral hemorrhage?

Answer 25

Hypertension (weakening of arterial walls)
Cerebral amyloid angiopathy (beta-amyloid deposited in the media and adventitia, associated with alzheimers)
Other cause of intracerebral hemorrhage (tumors, bleeding disorders etc)

Question 26

What is SAH usually caused by?

Answer 26

rupture of a berry aneurysm

cigarette smoking

Question 27

What are the mechanisms of recovery?

Answer 27

Neuronal plasticity - reorganisation aroudn the stoke
Recruitment of secondary motor areas in the ipsilateral hemisphere
Activation of homlogus areas of the unaffected (contralateral) hemisphere