STROKE & TIA Flashcards
Definition of stroke
A clinical syndrome of presumed vascular origin characterised by rapidly developing signs of focal or global disturbance of cerebral functions with lasts >24 hours or leads to death
What is a TIA?
a transient (less than 24 hours) neurological dysfunction caused by focal brain, spinal cord, or retinal ischemia, without evidence of acute infarctio
Most people have complete resolution of Sx and signs within 1 hour
What is a silent stroke?
radiological or pathological evidence of an infarction or haemorrhage not caused by trauma without an attributable history of acute neurological dysfunction attributable to the lesion
Epidemiology of stroke?
100,000 strokes every year in the UK
It’s a leading cause of death and disability - causes around 38,000 deaths a year in the UK
Non-modifiable risk factors for stroke?
Older age
Male
Race
Previous TIA or stroke
FHx - more common in black African or south Asian
Modifiable risk factors for stroke?
Hypertension
Diabetes
AF
CVD - valvular disease, CAD, CHF, MI, structural heart disease
Smoking
Hyperlipidaemia
Obesity
Poor diet and inactivity
Alcohol misuse
Drug abuse -cocaine and amphetamines
Migraines Hx
Other diseases - DM, sickle cell, APS, CKD, haemophilia, PCKD, connective tissue disorders, OSA, vascular malformations
What is the most important risk factor for cerebral haemorrhage?
Hypertension
Who is considered a young patient for a stroke?
<65
Risk factors specific for a “young stroke”?
Infarcts:
Arterial dissection
Heath abnormalities e.g. PFO or infective endocarditis
Vasculitis
Genetic e.g. CADASIL, MELAS
Illicit drug use
Haemorrhage:
AVMs
Aneurysms
Examples of stroke mimics?
Old stroke
Epilepsy
Todds paresis
Bell’s palsy
SOL
Head injuries
Delirium
Migraine
Mass lesion
MS
Encephalitis
Transient loss of consciousness
Hypoglycaemia
Hypoxia
Drug/alcohol use
Functional disorders
What are examples of stroke chameleons?
Acute confusional state e.g. receptive dysphasia
Abnormal movements / seizures
PNS symptoms e.g. pt presents with a wrist drop ans it actually turns out to be a stroke
Acute vestibular syndrome
(This are things commonly missed that are actually a stroke!!)
When does a CT scan have to be done if you suspect a stroke?
Within 1 hour of arrival to ED
Hyperacute findings on Non-contrast CT head after a stroke?
May directly visualise the clot immediately - hyper dense artery (white artery)
You may be able to see early parenchymal signs as early as 1 hour after onset. These may be loss of grey-white matter differentiation or cortical hypodensity with associated parenchymal swelling
Subacute findings on Non-contrast CT head after a stroke?
As time goes on, the swelling starts to subside and small amounts of cortical petechial haemorrhages (not to be confused with haemorrhagic transformation) result in elevation of the attenuation of the cortex. This is known as the CT fogging phenomenon 5. Imaging a stroke at this time can be misleading as the affected cortex will appear near normal.
Chronic findings on Non-contrast CT head after a stroke?
Later still the residual swelling passes, and gliosis sets in eventually appearing as a region of low density with a negative mass effect.
Cortical mineralisation can also sometimes be seen appearing hyperdense
Acute vs chronic CT head for a brain bleed
Acute - hyperdense i..e white
Chronic - hypodense i.e. black
What % of strokes are ischaemic?
85%
What are the 2 types of haemorrhagic strokes?
Remember 15% of all strokes are haemorrhagic…
10% of all strokes are intracerebral
5% are SAH
What causes an intracerebral haemorrhage?
Hypertension usually