Lecture 7 Current Treatments and Prevention

Question 1

What are the stages if diagnosing stroke?

Answer 1

1. Has a stroke occurred?
2. What type of stroke?
3. How severe is the stroke?
4. Can it be treated?
5. What’s the underlying cause?

Question 2

What are the aims of ischaemic and haemorrhagic stroke treatments?

Answer 2

Ischaemic: try to restore blood
Haemorrhage: try to stop the bleeding

Question 3

How can a CT scan be used in diagnosing stroke?

Answer 3

An x ray that takes lots of images at lots of different angles
If you took a scan of a person’s brain in the early stages of an ischaemic stroke it would look relatively normal, you can see the dead tissue and swelling in ischaemic strokes after 48 hours
Really good for identifying haemorrhage, can see the bleed as a white area
Can also be used to rule out haemorrhage

Question 4

How can MRI scans be used in diagnosing stroke?

Answer 4

Usually happens later down the line, can detect changes in the brain within about half an hour of the stroke occurring as it measures blood flow

Question 5

Where is the first zone of injury in an ischaemic stroke?

Answer 5

The ischaemic core:

• Severe ischaemia
• Blood flow <20%
• Loss of oxygen and glucose
• Neuronal cell death - called necrosis, cells die within minutes

Question 6

Where does the treatment focus on?

Answer 6

The surrounding region called the ischaemic penumbra:

• Moderately ischaemic tissue that lives outside the core
• Some blood supply from nearby arteries
• Injury can be reversed if blood supply is repaired
• Without treatment cells will die within hours

Question 7

What is sometimes given in cases of ischaemic stroke?

Answer 7

Aspirin to prevent other clots from forming

Question 8

What is the first line of treatment for ischaemic stroke?

Answer 8

Tissue Plasminogen Activator (TPA): a thrombolytic which activates plasminogen and turns into a compound called plasmin, breaks down the blood clot

Question 9

What are the risks of TPA?

Answer 9

Will only be effective if given within 3-4 hours of the stroke occurring (limited therapeutic time window)
Increases the risk of haemorrhage due to breaking down blood clots, this can be fatal
Have to consider other health issues/medications. The older the individual, more likely to have other issues

Question 10

What is one surgical treatment for ischaemic stroke?

Answer 10

MERCI retriever, but isn’t considered often because of the complications associated
Aim is to remove blood clot
Mechanical Embolus Removal in Cerebral Ischaemia
Insert wire into blocked artery, wire gets pushed into the artery just past the clot. When the sheath around the wire is retracted, the wire coils up and is slowly retracted, catching onto the cloth and removing it to restore blood flow.

Question 11

What is another alternative surgical treatment for ischaemic stroke?

Answer 11

Suction Removal
Insert tube into the artery, input a wire that comes out of the tube and poke the clot; breaking it up
The tube will suction out the little parts that have broken from the clot. Continuing to do this until it is all suctioned and normal blood flow is restored

Question 12

What is the goal of haemorrhagic treatments?

Answer 12

To manage the symptoms and stop the bleed. Definitely don’t want to administer TPA.

Question 13

What are individuals with a haemorrhage often given?

Answer 13

Antihypertensives to reduce blood pressure and decrease blood flow.

Question 14

What may happen if the brain is swelling due to haemorrhage?

Answer 14

It may put pressure on other areas of the brain such as the brainstem which would affect things like heart rate and breathing
In some cases they have to drill a hole into the skull to release the pressure

Question 15

What is the first example of surgical treatment for haemorrhagic stroke?

Answer 15

Aneurysm clipping

Clip down the aneurysm so the blood flow can’t go in that direction and then the blood flow continues as normal

Question 16

What is a second example of surgical treatment for haemorrhagic stroke?

Answer 16

Coil embolisation
Insert a tube into the artery wall and insert wire through the tube. The wire will fill up aneurysm space and block the blood from going in that direction
This will eventually clot up and seal.

Question 17

What are some non-modifiable risk factors of stroke?

Answer 17

Age, Gender, Ethnicity and Family History

Question 18

What is the impact of age on risk of stroke?

Answer 18

As you age, arteries will naturally become quite stiff and other areas might weaken,
The weakening may cause a bleed into the brain
Stiffness is usually due to fatty compounds, makes blood flow harder

Question 19

What is the impact of gender on risk of stroke?

Answer 19

Women prior to menopause have a lower risk of stroke due to levels of progesterone. Progesterone has been found to be a protective component
However, after menopause, progesterone levels drop and the risk between men and women is essentially equal
Women typically live longer than men, so their risk is increased because they live longer

Question 20

What are some modifiable risk factors of stroke?

Answer 20

Hypertension, Diabetes, Lifestyle, Cardiac diseases, High cholesterol, TIA

Question 21

How does hypertension increase risk of stroke?

Answer 21

It increases blood pressure, if RBCs knock into walls it can cause ballooning and increase risk of haemorrhage. Smaller blood vessels may also get thicker walls to compensate for the increased pressure and continue to get smaller until not much blood can get through.
These smaller vessels will either die or a stroke will occur

Question 22

How do all the lifestyle factors work together and influence each other?

Answer 22

High glucose damages artery walls
Tobacco can also damage blood vessel walls
High cholesterol can sit in these damaged walls and built up, a blood clot may form or the plaque can break off and travel through the brain possibly blocking a smaller blood vessel

Question 23

How do stroke units benefit stroke victims?

Answer 23

Stroke units compared to a general medical ward was proposed to reduce death and dependency at one year after a stroke by 5.6%
However, this depends on how effective and accessible they are to patients

Question 24

How does intravenous thrombolysis benefit stroke victims?

Answer 24

Intravenous thrombolysis within 6 hours of ischaemic stroke onset may reduce death and dependency from 62.7% to 56.4%
But it is only likely accessible and appropriate for up to 10% of strokes due to limited time frame

Question 25

What have studies on smoking found?

Answer 25

That smoking increases the risk of TIA and Stroke by at least 1.5 times.