Cerebrovascular disease Flashcards
Define the following conditions: Stroke, TIA, Amaurosis Fugax?
Stroke: a clinical syndrome caused by a thrombo-embolic or haemorrhagic event, characterised by rapidly developing signs of focal or global disturbance of cerebral functions, lasting for more than 24 hours or leading to death.
Transient Ischaemic Attack: same clinical presentation of a stroke which resolves within 24 hours
Amaurosis Fugax: a transient monocular vision loss that appears as a “curtain coming down vertically into the field of vision in one eye;” a specific type of TIA
List the risk factors leading toward the development of thromboembolic and haemorrhagic stroke?
Thromboembolic: Male (irreversiblle) Smoking Hypertension Obesity and Hypercholestrolaemia Diabetes AF IE Medication: POC
Haemorrhagic: Medication (warfarin etc) Bleeding disorders Hypertension Smoking
Describe the pathological causes of stroke?
Thrombo-embolic infarction: (~70%)
A combination of atherosclerosis of vertebral/intracerebral aa and emboli from:
-AF (leads to stasis forming a clot which can embolise)
-Ulcerated carotid plaques
-Mural plaque
-Infective endocarditis
Haemorrhagic:
Haemorrhage of an intracerebral vessel
SAH account for 5%
Describe the clinical features of a sub arachnoid haemorrhage, and the most common cause?
A sudden onset severe headache (peak pain almost immediately).
Worst headache ever.
Usually in the occipital region.
May be focal neurology and meningisms.
Most commonly due to a ruptured berry aneurysm in teh circle of willis.
Describe the clinical features of meningisms?
Neck stiffness, photophobia and headache.
Describe the vascular abnormalities which may predispose a patient developing a SAH?
Berry aneurysms: congenital weakness in the elastic lamina of aa, often develop at weak branch points in the circle of willis.
40% occur at the internal carotid aa
30% occur at the anterior communicating aa
20% occur at the middle communicating aa
Arteriovenous malformations: Congenital defect in which there are abnormal anastomoses between the arterial and venous system without capillaries due to the abnormal pressure difference these are more likely to bleed.
What are the complications of SAH?
The blood may spread through the sub arachnoid space leading to raised ICP.
There may be focal neurology due to infarction at the site of rupture.
If left untreated it will lead to death.
Describe the cause subdural haemorrhage?
Head trauma.
Occurs in a 1/3 of serious head traumas.
Often occurs in acceleration deceleration (blunt head trauma) when there has been damage to one of the bridging veins draining the blood from the cortex into one of the central venous sinuses.
Bleeding from a damaged cortical aa.
Describe the clinical presentation of an acute and chronic subdural haemorrhage?
Acute:
Usually presents shortly after a moderate to severe head trauma.
There may be a loss of consciousness.
There may be a lucid period of a few hours where the patient seems relatively well before deteriorating and losing consciousness as a haematoma forms.
Chronic:
Usually presents 2-3 weeks after the trauma, which may have been relatively uneventful (think of this in groups with a high bleeding risk)
Often a hx of progressive symptoms including:
Anorexia, nausea and vomiting.
Focal neurology such as limb weakness, speech difficulties, confusion or personality change.
May be a progressively worsening headache (should really raise suspicion)
Describe the predisposing factors making a patient vulnerable to developing a subdural haemorrhage?
Anything increasing bleeding risk.
Anticoagulants Liver failure Alcoholism (poor clotting and brain atrophy) Inherited haemophilias Infants and elderly (brain atrophy)
Describe what symptoms would be seen total anterior circulation and a partial anterior circulation stroke?
Higher cortical dysfunction (agnosia, neglect, dysphasia)
Hemianopia
Motor or sensory deficit
Note: hemianopia is on the same side as the hemiparesis
In a total anterior stroke all three are present in a partial 2 of the 3 are present.
Describe what symptoms would be seen in a posterior circulation stroke?
Isolated hemiapnopia OR Cerebellar ataxia OR Cranial nn lesions
Describe what symptoms would be seen in a lacunar stroke?
One motor or sensory deficit.
What is the name used to classify strokes?
Bamford classification.
Splits different strokes up into TACS, PACS, POCS and Lacunar based on the symptoms.
Which is the most serious stroke you can have and what is the 1 year mortality for the different strokes?
Right TACS as it will effect the left dominant hemisphere.
TACS 60%
PACS 15%
LACS 10%
Posterior circulation 20%
