stroke Flashcards
Define stroke and what is another name for it?
acute onset neurological deficits due to haemorrhagic or ischaemic vascular lesions aka infarction // sudden neuro event of vascular origin
CVA = CEREBROVASCULAR ACCIDENT:
The sudden death of brain cells due to lack of oxygen when the blood flow to the brain is impaired by blockage or rupture of an artery to the brain (stroke).
Symptoms of a stroke depend on the area of the brain affected. With CVA get infarction (death) of brain tissue. Deficit develops over time. Results in either death or some improvement over months
Define infarction
Define ischaemia
- Tissue death/necrosis due to inadequate blood supply to affected area – obstruction to blood flow
- inadequate blood supply to region caused by hypotension, vascular obstruction or both
Define the vascular lesions a/w stroke
Acute ischaemic stroke - due to thrombus/ embolus ;Thrombosis and embolism have similar consequences for the brain: loss of oxygen and metabolic substrates, resulting in infarction or ischemic injury of regions supplied by the affected vessel.
Haemorrhage - arachanoid/intracerebral
due to rupture of blood vessel causing direct injury and secondary ischemic injury
What are subtypes of a stoke?
1) Transient Ischaemic Attack
2) Acute ischaemic stroke
3) Acute haemorrhagic stroke
Define TIA
TIA = TRANSIENT ISCHAEMIC ATTACK:
A neurological event with the signs and symptoms of a stroke, but which go away within a short period of time (mini-stroke, duration<24 hrs). Due to a temporary lack of adequate blood and oxygen (ischemia) to the brain.
How to diagnose TIAs?
Diagnosis is based entirely off of history versus brain imaging
What is the risk of recurrence of TIAs?
highest in the first month
risk 8-10% at 7 days , 11-15% at 30 days
What are the symptoms to be assessed when considering TIAs as diagnosis?
Onset - sudden
Intensity- symptoms max at onset (gradual progression suggests demylelination, migraines or tumour– multiple/intermittent symptoms are atypical)
Focal symptoms-
carotid artery territory symptoms include amarosis fugax(embolic form of TIA in carotid territory which causes painless transient monocular blindness- described as a curtain, shade or mist descending over the eye) , hemianopia, dyshagia, contralateral weakness or numbness
vertebrobasilar territory symptoms - ataxia, vertigo, dysarthria, diplopia, hemianopia, bilateral visual loss (Uzi Ver(Tigo) and Diplo(pia) disguised (dysarthria) in ataxi(a) to prevent people from seeing them (bilateral visual loss)
duration- TIAs last 5-15 mins
Recognisable pattern- symptoms corresponding to a recognised territory of brain are supportive of TIA
headache- severe headache or eye pain is not a feature of TIA
loss of consciousness (syncope) is not a/w TIA
What are the symptoms that are not a/w TIAs?
severe headache eye pain syncope isolated dizziness, lightheadedness or vertigo seizure memory loss acute confusion gradual progression of symptoms multiple recurrent symptoms
Whar are the mimics of TIA
CNS tumours ocular disorders neuropathy and radiculopathy(pinched nerve) partial seizures syncope migraine hypoglycaemia vestibular disorders
How to assess prognosis (aka stroke risk) of TIAs?
ABCDD A-age >60 B-blood pressure >140/80 C-clinical symptoms a/w neuro deficit D-duration D-diabetes max score of 7
only applies for ACUTE TIAs not those which happened weeks/months ago
What is considered low risk, mod risk or high risk?
low risk - 0-3
mod risk - 4-5
high risk- 6-7
What is the consequence of a score greater than five (5) ?
should have immediate intervention and treatment within 24hr if possible
What is the a/ stroke risk with a score of 4-5 for 48hrs, 1 week, 3 months
and likewise for a score of 6-7
48 hrs- 4%
1 week- 6%
3 months- 10%
48 hrs- 8%
1 week- 12%
3 months- 18%
Management and investigations of TIA
Check Pulse, ECG, Neurological Examination
FBC, U&E,Fasting Glucose and Total Cholesterol
Urgent Carotid Doppler-Those with carotid circulation TIA who are fit for surgical intervention
?Prognostic Score-NICE recommends that patients with an ADCD2 score≥4 should be assessed and investigated within 24hrs.
No Driving for 30 days
What are some techniques to aid in secondary prevention?
Antithrombotic therapy
Aspirin+dipyridamole
Clopidogrel if intolerant of aspirin
Anticoagulation (following imaging) in Atrial Fibrillation
Blood Pressure Control (according to National guidelines)
Statin (if total chol>3.5mmol/l or LDL chol>2.5mmol/l)
Other secondary preventive measures-Smoking cessation, exercise, screening for Diabetes
What is TIA considered to be in regard to stroke?
A warning sign for strokes
30-40% of pts with ischaemic strokes have had earlier transient ischaemic attack or minor stroke
90 day risk of subsequent stroke is as high as 10.5%, with almost half occurring within the first 2 days
What are the risk factors for stroke?
Lifestyle- diet-obesity, smoking, Oral contraceptives
Medical- cholesterol-hyperlipidemia/atherosclerosis, atrial fib/CHD/LVH/valvular disease(aka heart diseases/impaired cardiac function due to embolism) ,thrombosis- haematocrit/fibrinogen, BP-hypertension, glucose-diabetes
Non modifiable- gender, age, genetics, race