Dovercourt Stroke Group

Different Types of Stroke Explained

Lacunar Stroke

Most of the time, strokes damage brain tissue in the outer part of the brain which is called the cortex, or sometimes called the “lobes” or “hemispheres” of the brain.  However, some strokes injure deep structures underneath the cortex.  A stroke in a deep area of the brain is called a lacunar stroke.  These deeper structures receive their blood flow through a unique set of arteries.  Because of the characteristics of these arteries, lacunar strokes happen a little bit differently from other strokes. A lacunar stroke occurs when one of the arteries that provides blood to the brain’s deep structures is blocked. Many of the deep brain organs that can be injured by a lacunar stroke help to relay communication between the brainstem and the brain cortex, or help to coordinate complicated body movements.  In a lacunar stroke, brain cells in a relatively small area are damaged or killed by lack of oxygen.  Such a small area of brain destruction is called a lacunar.  A lacunar stroke involves only a small area of the brain, but it can cause significant disability.

The symptoms of lacunar stroke vary depending on the part of the brain that is deprived of its blood supply.  Symptoms can include, weakness or paralysis of the face, arm, leg, foot or toes, sudden numbness, difficulty walking, difficulty speaking, clumsiness of the hand or arm, weakness or paralysis of eye muscles, or other neurological symptoms.The sudden appearance of one or more of these symptoms is a warning sign that a stroke may be in progress.

Spinal Strokes

A spinal stroke is a disruption in the blood supply to the spinal cord.  The spinal cord depends on a supply of blood to function properly.  A disruption in the supply causes tissue damage and can block messages (nerve impulses) travelling along the spinal cord.

The blood supply to the spinal cord involves a complex system of blood vessels.  The main blood vessels are the anterior spinal artery (at the front of the spinal cord) and the posterior spinal artery (at the back).  Spinal strokes are caused by bleeds.  These are called haemorrhagic spinal strokes.

Spinal strokes are a rare condition.  They are less common that strokes that affect the brain.  They account for 1.25% of all strokes.

The symptoms of a spinal stroke depend on what section of the spinal cord is affected.  The severity of the symptoms depends on how much damage is done to the spinal cord.

The main symptoms of spinal stroke are muscle weakness in the legs, change in sensation (unusual feelings) in the lower half of the body, pain, and problems with the bowel and bladder.

The symptoms of spinal stroke usually appear suddenly.  Sometimes a horizontal line or band can be drawn around the torso (the trunk of the body) or around the waist where the symptoms begin.  This is the point at which the damage has occurred to the spinal cord.

Muscle weakness in the legs can progress to a complete loss of movement (paralysis) very quickly.  People might experience muscle spasms (spasticity).

The unusual feelings people experience can include numbness, burning or tingling sensations, a heightened sensitivity to touch and temperature, and the inability to tell the temperature of water or objects.

Bowel and bladder problems might include incontinence (a loss of control over bowel movements or passing urine) or needing to go the toilet with increased urgency.

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Haemorrhagic Strokes

Most strokes are caused by a blockage in an artery leading to the brain – an ischaemic stroke.  However, about 15% are due to bleeding in or around the brain.  These are called haemorrhagic strokes.

Blood from the heart is pumped around the body through a network of blood vessels (called arteries).  This blood contains vital oxygen and nutrients.  If a blood vessel in or around the brain bursts it can cause bleeding, which is called a haemorrhagic stroke.

There are two main types:

  • bleeding within the brain (called an intracerebral haemorrhage)
  • bleeding on the surface of the brain (called a subarachnoid haemorrhage)

Bleeding within the brain

When an artery inside the brain bursts it is called an intracerebral haemorrhage.  About 10% of all strokes are of this type.  Because the blood leaks out into the brain tissue at high pressure, the damage caused can be greater than the damage caused by the strokes due to a blockage.

Symptoms of a stroke caused by bleeding in the brain can include weakness, numbness and/or pins and needles on one side of the body, difficulty speaking or understanding, dizziness, or blurred vision.  These can be accompanied by other symptoms such as a sudden, severe headache, altered consciousness, vomiting or a stiff neck.

Bleeding on the surface of the brain

The brain itself sits inside a cushion of membranes that protects it from the skull.  Between two of the layers of membranes is a space called the subarachnoid space that is filled with cerebrospinal fluid (CSF).  If blood vessels near the surface of the brain burst and blood leaks into the subarachnoid space, this is called a subarachnoid haemorrhage (SAH).  This accounts for 5% of all strokes.

Subarachnoid haemorrhages are a very serious type of stroke and about 50% of people who have one will not survive.

Often the only symptom is a sudden, severe headache.  This is sometimes described as like ‘being hit over the head with a hammer’ resulting in a blinding pain unlike anything you have experienced before.  Other symptoms can include altered, or loss of, consciousness, seizures, nausea and vomiting, sensitivity to light, neck stiffness (takes three to twelve hours to develop), confusion and fever.  These symptoms may also be accompanied by speech problems and weakness on one side of the body.

Ischaemic Stroke

A stroke happens when the blood supply to the part of the brain is cut off.  About 80% of strokes happen because of a blockage in an artery.  These are called ischaemic strokes.

An ischaemic stroke can either be caused by:-

  • a cerebral thrombosis – when a blood clot forms in the main artery leading to the brain or
  • a cerebral embolism – when a blood clot, or sometimes a piece of fatty debris from another part of the body is carried in the bloodstream to the brain.

There are a number of risk factors that increase the chances of having an ischaemic stroke.  Ones that we can’t change include:

  • age – strokes are more common as we get older
  • ethnicity – strokes are more common in South Asian and African Caribbean people
  • family history of stroke

A transient ischaemic attack (TIA) is very similar to a stroke, but the effects are temporary.  Symptoms may last for a few minutes or up to 24 hours but they should be treated seriously.  Most TIAs are caused by a blockage, rather than by bleeding in the brain.

Transient Ischaemic Attack (TIA)

A transient ischaemic attack (TIA) is often called a mini-stroke or mild stroke.  The symptoms are very similar to those of a full blown stroke, but they only last for a short time, anything from a few minutes up to 24 hours.  If you have had a TIA you will recover completely within about a day.  If your symptoms have lasted longer than 24 hours you have not had a TIA, you may have had a stroke.

A TIA is a sign that part of the brain is not getting enough blood and that there is a risk of a more serious stroke in the future.  Each year approximately 65,000 people have a first TIA.  There is no way of telling whether a TIA or stroke is occurring during the first few hours, so a TIA should be treated as an emergency and you should seek medical attention for assessment.

The FAST test (Face Arms Speech Time) helps people to quickly recognise the key symptoms of a TIA or stroke:

  • Facial Weakness: Can the person smile?  Has their mouth or eyelid drooped?
  • Arm Weakness: Can the person raise both arms?
  • Speech Problems: Can the person speak clearly and understand what you say?
  • Time to call 999….

If the person fails any one of these tests, they should seek urgent medical attention.  Other symptoms of a TIA or stroke may include:

  • Weakness, numbness, clumsiness or pins and needles on one side of the body, for example, in an arm, leg or the face.
  • Loss of or blurred vision in one or both eyes.
  • Sudden memory loss or confusion.
  • Slurred speech or difficulty finding some words.

A number of medical conditions can increase your risk of stroke including:

  • High blood pressure – the biggest risk factor of stroke.  High blood pressure can damage the artery walls, contributing to atherosclerosis (hardening and thickening of the large arteries in the body).
  • Atrial fibrillation – a type of fast and irregular heart beat.
  • High cholesterol – too much fat in your diet can lead to atherosclerosis.
  • Diabetes – a condition where your body does not produce any or enough insulin.  This means there are high levels of sugar (glucose) in your bloodstream and this can contribute to damage in your arteries.

Lifestyle factors can also increase your risk of stroke.  They include:

  • Smoking
  • Drinking too much alcohol
  • Eating an unhealthy diet
  • Being overweight
  • Lack of exercise

These lifestyle factors increase the chances of developing the medical conditions described above, and can contribute to damage of your arteries.

There are lots of things you can do to manage these risk factors and reduce your risk of stroke.  You can find more information on this within in our Stroke Prevention website pages.

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