Stroke - definitions, management and key concepts Flashcards
What are the FOUR sub-types of stroke
- Intrinsic vessel abnormality (e.g. atherosclerosis, inflammation, lipohyalinosis*, amyloid deposiiton, artierial disection, venous thrombosis)
- Embolism - embolus from the heart (most common) OR extracranial circulation lodges in an intracranial vessel
- Inadequate blood flow - the process may result from inadequate cerebral blood flow due to decreased perfusion pressure or increased blood viscosity.
- Vessel rupture – The process may result from rupture of a vessel in the subarachnoid space or intracerebral tissue.
List the sub-types of stroke that cause ischaemic strokes
vessel abnormality (e.g. atheroma), embolus, systemic hypoperfusion
List the sub-types of stroke that cause intracranial haemorrhages OR SAH
vessel rupture
How can thrombotic strokes be classified
1) large vessel disease
2) small vessel disease (smaller branches from arteries such as the basilar)
What are lacunes/lacunar strokes?
these are thrombosis in small arteries that can result in small deep infarcts
What is the sequale of an intracerebral haemorrhage?
bleeding directly into brain -> localised haematoma that gradually enlarges (like a snowball rolling downhill and accumulating snow).
where do intracerebral haemorrhages usually occur?
arterioles or small arteries
List the common causes of an intracerebral haemorrhage
Hypertension, trauma, bleeding diatheses, amyloid angiopathy, illicit drug use (mostly amphetamines and cocaine), and vascular malformations.
List 2 uncommon causes of intracerebral haemorrhage
- bleeding into tumours
- anerurysmal rupture
- vasculitis
In an intracerebral haemorrhage, what is the onset of neurological symptoms
usually GRADUAL - minutes to hours
What is the major cause of a SAH?
rupture of an arterial aneurysm
Describe the mechanism of a SAH if there is rupture of an aneursym
rupture of aneurysm into CSF under pressure > rapid spreading of blood > raised ICP
- HIGH risk of death if bleeding continues
- bleeding takes a few seconds but re-bleeding is common!
List 3 causes of a SAH that are not due to an aneurysm rupture
- vascular malformations
- bleeding diatheses
- trauma
- amyloid angiopathy
- illicit drug use
*of note bleeding less abrupt compared to aneurysmal bleeidng
What are the key symptoms/clinical presentation associated with a SAH?
- abrupt onset
- sudden, severe (worst) headache
- usually lateralised to the side of the aneurysm
- brief associated Sx of nausea, vomiting, seizure, brief LOC
*usually NO focal neurology unless there is bleeding into the CSF and brain at the same time
List 4 risk factors associated with cerebral venous thrombosis
- Prothrombotic conditions, either genetic or acquired
- Obesity
- Oral contraceptives
- Pregnancy and the puerperium
- Malignancy
- Infection
- Head injury and mechanical precipitants
What are the vessels involved in an ANTERIOR circulation stroke?
- anterior cerebral artery
- middle cerebral artery
Which cerebral artery territory do 2/3rds of ischaemic strokes occur?
middle cerebral artery
What is the dominant hemisphere in the brain?
LEFT - dominant
RIGHT - non-dominant
What does the term ‘apraxia’ mean?
inability to perform particular purposive actions, as a result of brain damage.
“dressing apraxia”
Describe the MCA stroke syndrome if the dominant (left) hemisphere was affected
- Right hemiparesis - Variable involvement of face and upper and lower extremity (if arm > leg likely MCA)
- Right-sided sensory loss in a pattern similar to that of the motor deficit -
- Right homonymous hemianopia
- Dysarthria
- Aphasia, fluent and nonfluent
- Alexia, Agraphia, Acalculia, Apraxia
Describe the MCA stroke syndrome if the non-dominant (right) hemisphere was affected
- Left hemiparesis - Same pattern as on right
- Left-sided sensory loss - Similar pattern that of the motor deficit
- Left homonymous hemianopia - Same pattern as on right
- Dysarthria
- Neglect of the left side of environment
- Anosognosia (unaware of condition)
- Asomatognosia (loss of awareness of a limb)
- Loss of prosody of speech
- Flat affect