Pathophysiology of stroke

 

Our brain is supplied by a rich supply of blood to keep brain cells, healthy, alive and functional. Most stokes occur in the region of the middle cerebral artery  a branch of the brains vascular system which supplies the primary motor cortex. The middle cerebral artery supplies the region of the brain which contains cortical representations of the upper limb  and this explains why upper limb impairments are more common than lower limb impairments.

 

The brain is supplied by a rich network of blood vessels known as the Circle of Willis and it supply’s the entire brain with a rich blood supply. Disruption to the blood supply will lead to a stroke. There are two ways in which the blood supply can be disrupted. This is through ischaemic or haemorrhagic strokes.

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Ischaemic and Haemorrhagic strokes

 

Ischaemic stroke

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Occurs in 70% of strokes. This is where the blood vessels become blocked. The blood vessels become blocked in a process known as atherosclerosis

 

Haemorrahgic stroke

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This occurs when the blood vessel burst. This can occur when there is an aneurysm a bulge in the blood (ballooning of blood vessels) as the vessel walls due to weakening of the walls which can occur as a result of high blood pressure. High blood pressure can wear down the artery walls and cause the walls to become weakened. 

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TIA and identifying stroke

 

TIA is also known as a mini stroke. Sufferers suffer the symptoms of a stroke but unlike a stroke where the effects are permanent, TIA sufferers usually return to normal function with 24 hours If such symptoms occur it is important you contact your GP or phone the ambulance immediately. 

 

Signs of Stroke and thinking FAST:

 

Thinking FAST and calling for help is the first sign to aiding recovery in the event of a stroke or TIA:

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F-Face: Dropping of the face usually on one side

A-Arms: Weakness in arms or legs

S-Slow Speech: slow or slurred speech

T-Time: Call 999 immediately and get help. The quicker helps comes the better the outcome.

 

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Risk Factors for Stroke

 

Age- Those over the age of 65 are more likely to get a stroke. However, this can occur in younger people. As we get older are blood vessels narrow and the elasticity of vessels diminishes creating a higher risk of blood not reaching the brain.

 

Family history- If a close relative has had a stroke a person is more likely to get a stroke. This is due to being genetically or culturally or socially more predisposed to the same factors leading to a stroke as members of your family.

 

Ethnicity- Those of African, Asian and Caribbean decent are more likely to get a stroke in the UK.

 

Medical history- If you have a medical history of stroke then you are more likely to get another stroke than someone who has never had a stroke. Risk Factors Smoking

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Other risk factors include:

•High blood pressure

•High cholesterol

•Inactive lifestyle

•Family history of diabetes and heart disease

•Irregular heartbeat-atrial fibrillation

•Stress

 

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Saving the brain after a stroke

 

Looking at the diagram below you see an area of permanent damage. This is the region of the brain that cannot be reived back to its normal function. 

 

Adjacent to that area is the Penumbra, an area of damage that can be restored. This is the area which current medicine attempts to firstly save and prevent further damage through and then later restore through therapy through facilitating neuroplasticity.

 

Neuroplasticity is the process in which brain cells adjacent to the damage area looks to form new connections.

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