Stroke Flashcards
What are 4 salient signs of acute stroke?
1) Sudden numbness/weakness of face, arm, leg
2) Sudden trouble seeing in one or both eyes
3) Sudden confusion/trouble speaking or understanding
4) Sudden trouble walking, dizziness, loss of balance, coordination
How are strokes classified?
1) Hemorrhagic/ischemic
2) Right or left sided
3) Anterior/partial/Posterior circulation
4) Lacunar(?)
How are specifically ischaemic strokes classified?
TOAST classification
1) Large artery atherosclerosis
2) Cardioembolic stroke
3) Lacunar stroke
4) Stroke of other determined etiology
5) Stroke of undetermined etiology
What are 2 ways to measure the severity of a stroke?
1) Glasgow coma scale
2) NIH stroke scale
What are 4 risk factors of stroke?
1) Hypertension
2) Diabetes mellitus
3) High lipids
4) Smoking
What are 2 indications for an acute stroke?
1) Antiplatelet therapy (eg. aspirin)
2) rTPA
What are 4 components of general management of an acute stroke?
1) Blood pressure (NOT in acute phase)
2) Blood glucose level
3) Body temperature
4) Neurological observation
What is the contention in treating hypertension in the acute phase of a stroke?
Against:
- BP returns to baseline after a few days normally → intervention may cause infarct extension due to ischemic penumbra and loss of autoregulation
For:
- may ↓ early hematoma expansion in intracerebral hemorrhage
When should BP be urgently lowered in a stroke patient?
1) Hypertensive encephalopathy
2) MI
3) CHF
4) Aortic dissection
5) Thrombolytic/anticoagulant therapy
What are the 3 BP goal in stroke?
Ischemic stroke: 220/120
Heparin: <200
TPA: <185/110
What are 5 Ix for a young stroke?
1) Phospholipid (cardiolipin) Ab profile
2) Inflammatory/collagen vascular disease
3) ATIII, Protein C & S
4) TEE
5) Angiography
6) Others
What is the core and penumbra of a stroke?
Core:
- little to no blood flow (<15%) → cells die rapidly
Penumbra
- area of ↓flow (<40%) → surrounds core
How does a recent stroke appear differently from a old stroke/
Over time intensity/density of stroke penumbra/core decreases
What is the main Ix indicated in an acute stroke?
Non-contrast CT
What are 3 goals of CT in an acute stroke setting?
1) Exclude intracranial hemorrhage precluding thrombolysis
2) Look for any “early” features of ischaemia
3) Exclude other intracranial pathologies that may mimic a stroke (eg. tumour)
Why is window height and width in a CT brain important?
To capture both brain and bone windows
What are 2 forms of cerebral edema?
Vasogenic:
- extravasation of fluid/serum proteins by BBB disruption
- inflammation, oxidative stress, glial activation, physical impact
Cytotoxic:
- Astrocytic swelling by disruption of intracellular ion balance → outflow of Na+ and fluid
- ATP depletion, mitochondrial dysfunction, oxidative stress
What are 3 modalities through which neuronal excitability can be recovered?
1) Resolution of cell and axon ionic disequilibrium and conduction block
2) Resolution of edema, inflammation, and circulation disturbances
3) Reverse diaschisis (depression of functionally connected brain regions)
What are 2 examples of maladaptive neuroplasticity?
1) Neuropathic pain
- dysesthesia or allodynia
2) Spasticity
- hyperexcitability of stretch reflex after CNS injury
What are 2 forms of neuronal plasticity?
1) Altered efficacy of synaptic activity
- potentiation, depression, activity-dependent unmasking, ↑responsiveness
2) Regeneration and sprouting
- angiogenesis, remodelling/growth
How does short term neuroplasticity differ from long term neuroplasticity?
ST: changes in chemistry
- synaptic efficacy through LT potentiation and depression
LT: changes in structure
- new dendritic growth and synaptogenesis
- cortical map reorganisation
What are 4 factors affecting neuroplasticity?
1) Age
2) Lesion size and site
3) Medications
4) Premorbid conditions
Why does time matter in stroke rehab?
Early rehabilitation prevents maladaptive neuroplasticity to develop
What is melodic intonational therapy for?
Severe, nonfluent aphasia
True or false:
Unlike in the CNS, PNS neurons are stable and thus do not exhibit neuroplasticity.
False.
Neuroplasticity exists in the spinal cord
What are 4 factors that are essential for rehab training?
1) Task-specific training
2) Appropriate repetition and intensity
- logarithmic law of practice → saturation
3) Feedback
- intrinsic and extrinsic → multisensory → reestabilish sensorimotor loop
4) Enriched environment
