Stroke and TIA Flashcards
What is a stroke?
Sudden onset of a focal neurological deficit, lasting more than 24 hours (or leading to death) due to either infarction (85%) or haemorrhage (15%).
Stroke should be suspected in all patients with acute neurological deficit.
What is a focal neurological deficit/sign?
Focal neurologic signs are impairments of nerve, spinal cord, or brain function that affects a specific region of the body, e.g. weakness in the left arm, the right leg, paresis, or plegia.
What is a TIA?
A transient ischaemic attack (TIA) describes stroke-symptoms lasting less than 24 hours.
- neurological dysfunction caused by focal brain, spinal cord, or retinal ischaemia, without acute infarction.
- can have numbness, visual loss, paralysis, ataxia, language, headache, sensation deficits
TIA - presentation
patient/caregiver report of focal neurological deficit
brief duration of symptoms (most < 1 hour)
presence of risk factors for CVD
unilateral symptoms, increase BP
What Investigations do you order for TIA?
blood glucose (hypoglycemia can lead to focal signs)
chemistry profile (rule out siezure)
FBC (rule out infection)
prothrombin time, INR, and activated PTT
ECG (rule out AF or other arrhythmia)
brain MRI with diffusion or CT (could localise an infarct so distinguish TIA from stroke)
fasting lipid profile (prior to starting statins)
TIA - management
- conservative: salt restriction, weight loss, healthy diet, exercise, and limited alcohol consumption
- antiplatelet: aspirin OR clopidogrel OR combination
- statins: atorvastatin OR simvastatin etc.
- with ≥50% carotid stenosis: carotid endarterectomy or stent
- anticoagulation if event is cardioembolic (warfarin or dabigatran or apixaban or rivaroxaban etc)
Signs of carotid artery occlusion
- Contralateral motor and sensory loss (arms and legs)
- Transient monocular blindness (ophthalmic artery occlusion = amaurosis fugax)
Signs of anterior cerebral artery occlusion
- Contralateral motor and sensory loss leg>Arm (can get foot drop)
- Confusion; personality changes (flat affect)
- Can get Incontinence or gait apraxia
Signs of middle cerebral artery occlusion
- Contralateral motor & sensory loss Arm>Leg + Face
- Contralateral Visual field loss (hemianopia)
- aphasia, loss of spatial orientation, dysphagia
- malignant MCA: rapid neurological deterioration due to cerebral oedema and mass effect following MCA stroke. Early neurological decline + headache, vomiting
Total anterior circulation stroke (TACS)
All three of:
- Unilateral weakness +/- sensory loss of face, arm + leg.
- Homonymous hemianopia.
- dysphasia, visuospatial problems
Posterior circulation stroke (POCS)
Cerebellar or brainstem syndromes, loss consciousness or isolated homonymous hemianopia, colour agnosia, dysarthria, dysphagia, diplopia or quadruparesis.
- Vertebrobasilar stroke = Cranial nerve deficits 3rd
to 12th. Can have bilateral blindness or hemianopia, Confusion; Diplopia, Slurred speech or Vertigo
- subclavian steal syndrome = occluded subclavian > retrograde circulation in vertebral or internal thoracic at expense of vertebrobasilar flow > dizziness, vertigo, arm pain
- basilar artery occlusion (locked in syndrome) = loss of speech, quadriplegia, preserved cognitive function
Lacunar Infarct (LACS) / small vessel
- most common ischemic stroke
- lipohyalinosis + HTN in small penetrating arteries
- affects internal capsule and basal ganglia
- Either unilateral weakness of face and arm,
arm and leg or all three. Ataxic hemiparesis (weakness legs > arms)
Ischaemic stroke - aetiology
- arterial atherosclerosis
- HTN
- cardioembolism
- vasculitis
- arterial dissection
Haemorrhagic stroke - aetiology
- Cerebral amyloid angiopathy (CAA) = beta-amyloid deposition in the walls of arteries of brain cortex and cerebellum. Sporadic (generally elderly) or in familial forms (eg apolipoprotein (Apo) E4 allele )
- HTN
- anticoagulation-associated haemorrhage
- Sympathomimetic drugs of abuse, such as cocaine and amfetamine (transient increase in BP)
- Brain arteriovenous malformations (AVMs)
What are the types of haemorrhagic stroke?
- intracerebral haemorrhage
- subarachnoid haemorrhage
forms of intracranial hemorrhage, which is the accumulation of blood anywhere within the cranial vault; as well as epidural hematoma and subdural hematoma (not strokes)
