Stroke - Pathology Flashcards
What is a stroke characterized as?
- rapidly developing clinical symptoms (sometime TIA previously)
- loss of cerebral function (focal or global disturbance)
- lasting more than 24 hours (or lead to death)
- presumed vascular origin
What is a TIA?
Transient Ischaemic Attack
- episode of inadequate blood supply to the brain (leading to hypoxia)
- episode of neurological dysfunction caused by focal brain, SC or retinal ischaemia, WITHOUT acute infarction (sudden or severe bloody supply cut off leading to cellular death)
Stoke risk factors
non- modifiable:
- age
- ethnicity
- bloody disorders
- TIA or previous strokes
modifiable:
- diabetes
- hypertension (high BP)
- smoking
- alcohol
- obesity
- atherosclerosis (build up of fats/cholesterol in artery walls)
Two major types of stroke
- Ischaemic
- clot, blockage of a blood vessel (brain or neck)
a. thrombosis - in situ blood clot in brain/neck
b. embolism - blood clot from else where has moved now blocking vessel in brain/neck
c. stenosis - narrowing of artery in head/neck - Hemorrhagic
- bleeding in and around the brain of a blood vessel
What is the penumbra? Which type of stoke associated with?
- associated with ischemic stoke
- outer and around the region of infarction in the brain tissue
- neurons are affected but not dead cells > neurons are still viable and damage is reversable
- treatment is to salvage penumbra as much and as early as possible
Carotid arteries: bifurcate? names? supplies?
- common carotid which bifurcates (divide in two) - at level of C4
- external carotid > supplies face and scalp (external tissues)
- internal carotid > supplies anterior 3/5 of cerebrum
What are the paths of cerebral circulation? x3
- VERTEBROBASILAR ARTERIES > two vertebral arteries, left and right, join at the base of the skull forming the basilar artery > together they are called the vertebrobasilar arteries > also consist of posterior cerebral arteries and cerebella arteries > supply posterior 2/5 of cerebrum, part of cerebellum, brainstem
- CIRCLE OF WILLIS > joins the anterior and posterior circulation > route for secondary or collateral circulation > allows alternative blood flow route
- ANTERIOR CEREBRAL CIRCULATION > branches off the interior carotid artery > ophthalmic > anterior cerebral > middle cerebral > supply anterior 3/5 of cerebrum, diencephalon and basal ganglia
What are the main clinical features of stroke? x4
- sensory and motor disturbance
> unilateral weakness of face/arm/leg (hemiplegia)
> unilateral sensory deficit of face/arm/leg - visual disturbance
> homonymous hemianopia (loss in same halves of visual field in each eye) - higher cerebral disfunction
> speech, visuospatial, cognitive - cerebellar or brainstem symptoms
> loss of functional ability
How can stokes be classified? scale?
BAMFORD classification
- Total Anterior Circulation Stroke (TACS)
- Partial Anterior Circulation Stroke (PACS)
- Lacunar Syndrome (LACS)
- Posterior Circulation Syndrome (POCS)
What is TACS and how is it classified?
Total anterior circulation stroke
- large cortical stroke in middle/anterior cerebral artery areas
- clinical features:
1. unilateral weakness
2. homonymous hemianopia
3. higher cerebral dysfunction
“3 out of 3”
What is PACS and how its classification?
Partial anterior circulation stroke
- lesser cortical stroke in middle/anterior artery areas
clinical features:
1. unilateral weakness
2. homonymous hemianopia
3. higher cerebral dysfunction
“2 out of 3”
What is LACS and how its classification?
Lacunar syndrome
- subcortical stroke due to small vessel disease (small area of brain cells damaged/killed due to lack of oxygen)
- NO evidence of higher cerebral dysfunction
clinical features - ONE of…
1. unilateral weakness
2. pure sensory stroke
3. ataxic hemiparesis
What is POCS and how its classified?
Posterior circulation syndrome
clinical features - ONE of…
1. cerebellar or brainstem syndromes
2. loss of consciousness
3. homonymous hemianopia
