Stroke & Recovery

Question 0

Stroke: haemorrhage

Answer 0

Bleeding, weak vessels rupture

Aneurysm and AVM

Question 1

Stroke: isechemia

Answer 1

Thrombosis - develops at clogged section
Cerebral embolism - travels
Atherosclerosis - cholesterol / fatty deposits

Question 2

Stroke : transient isechemic attacks

Answer 2

Warning, temporary

Less than 5 minutes

Question 3

Local stroke

Infarcts

Answer 3

Cell death due to lack of oxygen and nutrients

Question 4

Local stroke

Penumbra

Answer 4

Region around infarcts

Suffered loss of blood but tissue is still alive

Question 5

Distant stroke effects

Answer 5

Diaschesis

Damage in one brain area extends to distant areas

Question 6

Experimental stroke

MCAO

Answer 6

Middle Cerebral Artery Occlusion model
No surgery, stimulates clot
Remove after 30-120min to create spontaneous reperfusion
Damage in MCA, sensory & motor complications
Used in rats

Question 7

Number of strokes in a year

Answer 7

150,000

Question 8

Number disabled by a stroke in a year, UK

Answer 8

450,000

Question 9

Stroke : common death?

Answer 9

3rd most common cause of death

Question 10

Who is more affected by strokes?

Answer 10

Women more likely to die
Men have a higher risk of stroke
South Asian/Afro-Caribbean increased risk

Question 11

Risk factors for stroke

Answer 11

Heart disease
Smoking
High blood pressure

Question 12

What happens in a stoke?

Answer 12

Neurons are deprived of nutrients and oxygen
Permanent damage after 2mins
Apoptopic and necrotic cell death

Question 13

MCA

Answer 13

Middle Cerebral Artery

Supplies motor and speech areas

Question 14

Stroke recovery
Rehabilitation
Nudo et al (96)

Answer 14

Monkey - Lesion in part of hand representation
Retrained hand use
Expansion of representation depended on use/training
Undamaged MC important

Question 15

Stroke recovery
Rehabilitation
Libert et al (00)

Answer 15

Humans stroke SS
Unaffected arm restrained for 8h a day for 12days
Sig recovery compared to before therapy
Sig enlargement of limb in injured hemisphere

Question 16

Stroke recovery
Remapping remote areas
Frost

Answer 16

PMC is connected to the ventral PMC: access to spinal cord and motor

Frost - ICMS to map hand in M1 and PMv,
Focal isechemic lesion in M1
12w monitor, then remapping
M1 representation decreased, PMv increased (proportionate)
PMv took over motor function

Question 17

Stroke recovery
Time periods
Biernaskie et al (04)

Answer 17

Animal study, enriched rehabilitation effective immediately
MCAO given to rats, rehab after 5/14/30days
Sooner = better recovery
14/15days sig recovery
More dendritic branches and longer at 5days

Question 18

Stroke recovery
Time periods
Horn et al (05)

Answer 18

5x US facilities
n830 post stroke rehabilitation SS
Sooner & more challenging the rehab - better outcome
Even in low functioning SS

Question 19

Stroke recovery

Redundancy

Answer 19

Alternative mechanisms

Question 20

Stroke recovery

Contra lateral pathways

Answer 20

Sensory and motor organisation connect each hemisphere via corpus callosum - function could be supported by another area

Question 21

Stroke recovery

Remapping

Answer 21

“Wake” the penumbra by remapping connections

Limited time, activity dependent

Question 22

Stroke recovery
Remapping
Glees & Cole (59)

Answer 22

Electrodes: thumb representation damaged but reappeared in penumbral area

Question 23

ICMS

Answer 23

Intracranial Micro Stimulation

Question 24

Stroke recovery
Remapping
Nudo & Milliken (96)

Answer 24

ICMS mapped forelimb movement in squirrel monkey
Created isechemic infarct
Deficit in contralateral hand
Remapped later: increase in adjacent representations
Lost movement didn’t reappear in adjacent cortical regions

Question 25

Stroke recovery
Remapping
Cramer et al (06)

Answer 25

N15
Good stroke recovered humans
fMRI on surrounding cortical infarct
Activity present, but less than controls