DDT - Stroke

What is a stroke

An instantaneous lack of blood in the brain which has resulted in a loss of neurological function. TIA (transient ischaemic attack) is known as a mini-stroke, and is typically a precursor to a stroke

Stroke risk factors

High blood pressure (normal 120/80mmHg), cigarette smoking (15% of all strokes in the UK), atrial fibrillation, diabetes, high cholesterol, carotid stenosis, obesity, Iatrogenic (illness caused by treatments or medical examinations), ethnicity, male risk higher than female

Arteries that bring blood to the brain

2 carotid arteries, vertebral and basilar arteries supply

Effects of stroke on regions of the brain

Anterior cerebral artery

Sensory/ motor control lower body

Mental state impairment

Middle cerebral artery

Upper limbs and face

Broca's Aphasia (LHS)

Posterior Cerebral artery

Visual field

Basilar artery

Locked in syndrome

Cerebellar artery (branched from basilar artery)

Poor co-ordination/ muscle tone

Dysphagia

What is infarction?

Tissue death is caused by a lack of oxygen due to a blockage in the blood supply. The most common area of infarction is the middle cerebral arteries

What is a penumbra and core

Penumbra is the area which could suffer damage from ischaemia BUT it is reversible. The core is damaged areas caused by infarction that cannot be repaired at all. Penumbra is also going to cause apoptosis, rather than core, which will cause necrosis

Inflammatory response to stroke

Neutrophils: Appear in the middle cerebral artery occlusion after a few hours
Lymphocytes: Appear within 24 hours (Makes tissue damage caused by stroke worse)
Microglia: Release pro-inflammatory cytokines
After a while, debris is digested via phagocytosis and beneficial cytokines may be released

Embolism meaning

Something that is able to block blood vessels

Pyknotic meaning

Nucleus shrinkage in necrotic cell

Angiogenesis meaning

Production of new blood vessels

Ways to diagnose strokes

FAST (Face dropped on one side, Arm(s) cannot be raised, Speech is slurred, Time to call 999) MRI, CT which need to be done as soon as possible to understand nature of stroke and deal with it

Treatment methods for strokes

Thrombolysis, thrombectomy, aspirin (stops platelet build up in blood vessels) as well as warfarin (antithrombotic treatment. Prevent the production of vitamin K, vital for thrombosis. Dangerous fo those with clotting factor defects however)

Overview of clotting (both intrinsic and extrinsic)

Window of opportunity for effective thrombolysis

4.5 hours from when the stroke first started

What is mechanical thrombectomy?

A catheter attached to a thin wire is put into the artery at the groin, which then goes to the brain, and is only used for those with severe ischaemic stroke, to remove a blood clot

What is haemorrhagic transformation

Where blood leaks into the brain, from a disrupted blood-brain barrier, which can worsen the effects of a stroke