Stroke

Question 1

What are 4 salient signs of acute stroke?

Answer 1

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

Question 2

How are strokes classified?

Answer 2

1) Hemorrhagic/ischemic
2) Right or left sided
3) Anterior/partial/Posterior circulation
4) Lacunar(?)

Question 3

How are specifically ischaemic strokes classified?

Answer 3

TOAST classification
1) Large artery atherosclerosis
2) Cardioembolic stroke
3) Lacunar stroke
4) Stroke of other determined etiology
5) Stroke of undetermined etiology

Question 4

What are 2 ways to measure the severity of a stroke?

Answer 4

1) Glasgow coma scale
2) NIH stroke scale

Question 5

What are 4 risk factors of stroke?

Answer 5

1) Hypertension
2) Diabetes mellitus
3) High lipids
4) Smoking

Question 6

What are 2 indications for an acute stroke?

Answer 6

1) Antiplatelet therapy (eg. aspirin)

2) rTPA

Question 7

What are 4 components of general management of an acute stroke?

Answer 7

1) Blood pressure (NOT in acute phase)
2) Blood glucose level
3) Body temperature
4) Neurological observation

Question 8

What is the contention in treating hypertension in the acute phase of a stroke?

Answer 8

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

Question 9

When should BP be urgently lowered in a stroke patient?

Answer 9

1) Hypertensive encephalopathy
2) MI
3) CHF
4) Aortic dissection
5) Thrombolytic/anticoagulant therapy

Question 10

What are the 3 BP goal in stroke?

Answer 10

Ischemic stroke: 220/120
Heparin: <200
TPA: <185/110

Question 11

What are 5 Ix for a young stroke?

Answer 11

1) Phospholipid (cardiolipin) Ab profile
2) Inflammatory/collagen vascular disease
3) ATIII, Protein C & S
4) TEE
5) Angiography
6) Others

Question 12

What is the core and penumbra of a stroke?

Answer 12

Core:
- little to no blood flow (<15%) → cells die rapidly

Penumbra
- area of ↓flow (<40%) → surrounds core

Question 13

How does a recent stroke appear differently from a old stroke/

Answer 13

Over time intensity/density of stroke penumbra/core decreases

Question 14

What is the main Ix indicated in an acute stroke?

Answer 14

Non-contrast CT

Question 15

What are 3 goals of CT in an acute stroke setting?

Answer 15

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)

Question 16

Why is window height and width in a CT brain important?

Answer 16

To capture both brain and bone windows

Question 17

What are 2 forms of cerebral edema?

Answer 17

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

Question 18

What are 3 modalities through which neuronal excitability can be recovered?

Answer 18

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)

Question 19

What are 2 examples of maladaptive neuroplasticity?

Answer 19

1) Neuropathic pain
- dysesthesia or allodynia

2) Spasticity
- hyperexcitability of stretch reflex after CNS injury

Question 20

What are 2 forms of neuronal plasticity?

Answer 20

1) Altered efficacy of synaptic activity
- potentiation, depression, activity-dependent unmasking, ↑responsiveness

2) Regeneration and sprouting
- angiogenesis, remodelling/growth

Question 21

How does short term neuroplasticity differ from long term neuroplasticity?

Answer 21

ST: changes in chemistry
- synaptic efficacy through LT potentiation and depression

LT: changes in structure
- new dendritic growth and synaptogenesis
- cortical map reorganisation

Question 22

What are 4 factors affecting neuroplasticity?

Answer 22

1) Age
2) Lesion size and site
3) Medications
4) Premorbid conditions

Question 23

Why does time matter in stroke rehab?

Answer 23

Early rehabilitation prevents maladaptive neuroplasticity to develop

Question 24

What is melodic intonational therapy for?

Answer 24

Severe, nonfluent aphasia

Question 25

True or false:
Unlike in the CNS, PNS neurons are stable and thus do not exhibit neuroplasticity.

Answer 25

False.
Neuroplasticity exists in the spinal cord

Question 26

What are 4 factors that are essential for rehab training?

Answer 26

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