Cerebral Infarction (Clinical) Flashcards
What is the definition of a stroke?
The sudden onset of focal or global neurological symptoms caused by ischemia or hemorrhage and lasting more than 24 hours.
About 85% of strokes are ischemic.
What is a transient ischaemic attack?
TRANSIENT ISCHEMIC ATTACK (TIA)
is the term used if the symptoms resolve within 24 hours.
Most TIAs resolve within 1-60 min.
What are the causes of ischaemic stroke?
Larger artery atherosclerosis
Cardioembolic (e.g atrial fibrillation)
Small artery occlusion (lacune)
Undetermined/cryptogenic
Rare causes (arterial dissection, venous sinus thrombosis)
What are the haemorrhagic causes of stroke?
Primary intracerebral hemmorhage - no tumour or aneurysm (may be as a result of high blood pressure or amyloid angiopathy)
Secondary haemorrhage (subarachnoid haemorrhage, arteriovenous malformation)
Define ischaemic penumbra
The area surrounding an ischaemic event
What is the result of anoxia on cells?
Infarction - complete cell death leading to necrosis
How can further damage result from a stroke?
Edema (depending on size and location of the stroke)
Secondary haemorrhage into the stroke
What are the stages of pathogenesis of ischaemic stroke?
What are the non-modifiable risk factors for stroke?
–Previous stroke
–Being old
–Being male
–Having a horrible family history
- Diabetes
What are modifiable risk factors for stroke?
Hypertension
Smoking
Cholesterol
Diet
High BMI
Sedentary
Alcohol
What is the most important modifiable risk factor for stroke?
Hypertension
What is the problem with chronic high blood pressure?
•Chronic hypertension worsens atheroma and affects small distal arteries.
Also a major risk factor in haemorrhagic strokes
Why does increased serum lipid increase stroke risk?
Due to blood vessel wall atheroma
What is the result of increased plasma level of LDL?
Excessive amounts of LDL within the arterial wall
What is the effect of hypertension, cigarette smoke and diabetes on LDL-C?
•Hypertension, cigarette smoke, and diabetes contribute to LDL-C deposition in arterial walls.
How does alcohl affect stroke risk?
Small amounts of alcohol reduces stroke risk
Heavy drinking increases stroke risk by 2.5 fold
What is the result of obesity on vascular disease?
Risk factor for vascular disease including stroke (especially abdominal obesity)
Other important risk factors
Imparied cardiac function (recent heart attack, atrial fibrilaltion)
Oral contraceptives (+HRT) with a high estrogen content. Progesterone only ok
Hypercoagulable states: malignancy, genetic
What comprises the anterior circulation of the brain?
2 internal carotid arteries
2 anterior cerebral arteries
2 middle cerebral arteries
What comprises the posterior circulation of the brain?
2 vertebral arteries - 1 bassilar
3 pairs of cerebellar arteries
2 posterior cerebral arteries
What are symptoms of ACA occlusion?
Contralateral:
Paralysis of foot and leg
Sensory loss over foot and leg
Impairment of gait and stance
What are the symptoms of MCA occlusion?
Contralateral
- Paralysis of face/arm/leg
- Sensory loss of face/arm/leg
- Homonymous hemianopia
Gaze paralysis to the opposite side
Aphasia if stroke on dominant (left side)
Unilateral neglect and agnosia for half of external space if non-dominant stroke (usually right side)
Agnosia - inability to interpret sensations and hence to recognise things
Whcih part of the optical tract will a lesion cause a problem in 1 eye and 2 eyes?
Anything in front of the optic chiasm is a on eye problem
Behind the optic chiasm it is a two eye problem
Left hemisphere lesion
Hemiplegia, homonymous hemianopia, dysphasia
