ILA 6 - Stroke

Question 1

Why would Atrial fibrillation be a risk factor for stroke?

Answer 1

pooling of blood in atria when thromboses.
can embolise to carotids.

Question 2

What term is used to describe transient visual disturbance and why does it occur?

Answer 2

amaurosis fugax - “fleeting darkness”
atherosclerosis in internal carotid or opthalmic/retinal artery

Question 3

pt walks in with occasional palpitations ,sob and irregularly irregular heart beat. what cardiac rhythm?

Answer 3

atrial fibrillation - irregularly irregular
electric signals randomly make it across bundle of his in ventricles.
contract as disorganised intervals

blood pooling in atria , thromboses , embolises in carotid possibly

Question 4

if in stroke weakness is on right where in the brain does it affect?

Answer 4

left

Question 5

symptoms of middle cerebral artery stroke

Answer 5

hemianopia
contralateral sensory loss
contralateral arm and leg weakness
aphasia
dysphagia
facial droop

Question 6

patients bp is increasing, hr slowing , breathing is erratic. what intracranial process is occuring?

Answer 6

raised intracranial pressure
ischaemic tissue creates inflammatory response = cerebral oedema= raised icp.

Question 7

explain the cushings reflex in response to increased icp ?

Answer 7

when csf, venous system, arteries all squashed, cerebral perfusion pressure inm arteries is too low to perfuse the brain = more ischaemia

arterial smooth muscle increases bp by vasoconstriction but baroreceptors in aorta stressed out = bp increase = bradycardia to bring bp down.

Question 8

in Cushing’s reflex why does bp increase and hr slow?

Answer 8

compensatory mechanism

CO = pulse pressure * HR
pp = sbp - dbp

if hr slows bp must increase to maintain CO.

Question 9

define tia

Answer 9

transient ischaemic attack
acute neurological dysfunction - sudden onset , resolves within 24 hrs.

not a stroke because its ischaemic not infarction

Question 10

location, vessel and criteria for total anterior circulatory stroke (tacs) BAMFORD (35%)

Answer 10

• large cortical stroke
• anterior or middle cerebral artery
• all 3 symptoms :

1. unilateral weakness of face, arms or/and legs
2. homonymous hemianopia
3. higher cerebral dysfunction

Question 11

location vessel and criteria for PACS - partial artery circulatory stroke BAMFORD (15%)

Answer 11

• cortical stroke
• anterior or middle cerebral artery
• 2/3 TACS symptoms

Question 12

location vessel and criteria for lacunar stroke - LACS - BAMFORD (25%)

Answer 12

• subcortical stroke
• small deep perforating arteries
• symptoms:

1. ataxic hemiparesis
2. at least 2 of : pure motor, sensory or sensorimotor (min 2 face,arm,leg)

Question 13

location vessel criteria for Posterior circulation stroke - PCOS - BAMFORD (25%)

Answer 13

• cortical, cerebellum, brainstem stroke
• posterior cerebellar artery, vertebral artery, basilar artery and branches
• symptoms:
  1. loss of consciousness
  2. isolated homonymous hemianopia
  3. cerebellar or brainstem syndrome

Question 14

what is the cushing reflex triad?

Answer 14

1. bradycardia
2. hypotension
3. irregular breathing

Question 15

tx to lower icp

Answer 15

iv mannitol
ultimate: burrhole washout/craniotomy surgery.

Question 16

what would you see on a ct in haemorrhagic stroke?

Answer 16

midline shift
and increase icp

bleeding/cerebral oedema causes increase in pressure on brain structures causing:
1. papilledema
2. cn6 palsy
3. seizures
4. loss of consciousness