wTypes of strokes:
Ischaemic stroke
Haemorrhagic stroke
Can also get a transient ischemic attack
What is a stroke
WHO definiton: rapidly developing clinical signs of focal/general disturbance of cerebral function with symptoms lasting 24hours or longer or leading to death, with no apparent cause other than vascular origin
patients with similar symptoms due to: tumours, subdural haemotoma, poisoning, trauma are not considered strokes
Stroke vs TIA
TIA: brief episode of neurological dysfunction typically lasting less than 1 hour (up to 24hour) with a vascular cause and with no evience of infarction (cell death) on imaging
Stroke: rapidly developing clinical signs of focal/general disturbance of cerebral function with symptoms lasting 24hours or longer or leading to death, with no apparent cause other than vascular origin
Ischaemic Stroke
87% of strokes are ischaemic
occurs due to blockage of blood flow
Ischaemic tissue is weaker and at a bleeding risk -> risk of haemorrhagic transformation
Mechanisms of ischaemic stroke
Circle of Willis anatomy
Signs and symptoms of ischaemic stroke (Bamford (oxford) classification)
Based on clinical findings
Internal carotids: Anterior circulation
Vertebral arteries: Posterior circulatoin
Diagnosis for ischaemic stroke
Treatment for ischaemic stroke
Secondary Prevention of Ischaemic Stroke
What is a haemorrhagic stroke
15-20% are haemorrhagic
result from vessel rupture
Types of haemorrhagic stroke:
*These intracranial bleeds are considered strokes, others (epidural/subdural) are not considered strokes
Causes of intracerebral haemorrhage
hypertension
arteriovenous malformations
cerebral amyloid angiopathy
Vascular tumpurs
Vasculitis
Can also be secondary to an ischaemic Stroke
Causes of subarachnoid haemorrhage
85% of spontaneous subarachnoid haemorrhage are due to rupture of an aneurysm
-Anterior communicating artery 35%
-Internal Carotid 30%
-Middle Cerebral artery 22%
15% due to arteriovenous malformation, coagulopathy, intraparenchymal extension
Signs and symptoms of haemorrhagic stroke
Diagnosis of haemorrhagic stroke
Treatment/management for haemorrhagic stroke
Agents used:
Labetalol
Nimodipine/nicardipine
Enalapril
Hydralazine
Secondary Prevention of Haemorrhagic Stroke
What is a TIA (Transient Ischaemic Attack)
Brief period of ischaemia due to emboli/stenosis of brain in the carotid artery
Infarction is very unlikely in a TIA
Causes of TIA
Modifiable:
Alcohol
Hypertension
Smoking
Hyperlipidaemia
Diabetes Mellitus
Obesity
High Fat diet
Stress
Unmodifiable:
Age
Family History
Male
Pathogenesis
Emboli in carotid artery and plaques leads to impaired perfusion of brain tissue
Symptoms of TIA
Contralateral hemiparesis
Dysarthria
Vision problems
Gait disturbance
Carotid bruit on physical exam -> due to atherosclerosis of carotid artery
Diagnosis of TIA
Carotid ultrasound
CT of head
Treatment of a TIA
Aim is to prevent a stroke
-Antiplatelet medication: clopidagrel
-Decrease lipids via statins
Surgery: carotid endarterectomy (surgical removal of plaque and correction of stenosis if stenosis >70%)