Transient Ischaemic Attack
Transient Ischaemic Attack
Warning Signs of Stroke
A stroke may be caused by (a) blockage of a blood vessel within the brain (cerebral infarction), (b) rupture of a blood vessel within the brain (cerebral haemorrhage), or (c) rupture of a blood vessel into the space surrounding the brain (subarachnoid haemorrhage).
About 50% of patients who subsequently have a stroke due to blockage of a blood vessel have a small warning episode termed a transient ischaemic attack (TIA).
In 75% of TIAs the symptoms clear within one hour, often within only a few minutes, because the blockage in the artery clears itself very quickly. 30% of people have damage evident on sensitive brain imaging techniques such as MRI after a TIA.
TIAs are significant and must not be ignored. Advice must be sought immediately. A TIA may be the start of a stroke that can follow the TIA within hours.
TIAs can warn of a future stroke. Treatment can reduce the risk of having a stroke.
Symptoms of Transient Ischaemic Attacks - Warning Strokes
FLEETING BLINDNESS OR BLURRING OF VISION
In one or both eyes, lasting for a few seconds or minutes only, like a curtain descending or ascending from above or below, very occasionally crossing from one side to the other.
Objects may suddenly appear to be double horizontally or vertically, may be more marked when looking in one direction.
OTHER VISUAL DISTURBANCES
Such as difficulty seeing one or other of the visual fields to the left or right.
Such as impaired expression of speech, knowing what one wishes to say but being unable to say it, using words of a similar type with different meanings.
SLURRING OF SPEECH
Often with an accompanying sensation that the tongue is moving clumsily or 'thick'.
FACIAL NUMBNESS OR WEAKNESS
Usually in conjunction with slurring of speech.
Occasionally this may accompany slurring of speech.
WEAKNESS OR PARALYSIS OF FACE, ARM OR LEG
A brief episode of weakness or clumsiness affecting face, arm or leg separately or in combination- a typical case is weakness affecting the right arm or leg together with speech disturbance, resulting in an object being dropped, the limb feeling heavy or even numb or tingling. Sometimes there is a profound weakness and inability to move limbs on one side of the body. The symptoms may occur on repeated occasions. At other times, the symptoms are minimal, a brief moment of clumsiness while using a knife or fork or writing. Occasionally symptoms will involve one side of the body followed by the other in quick succession.
A spinning sensation usually experienced with other symptoms.
LOSS OF BALANCE
May be a tendency to veer to one side or the other, or difficulty in remaining upright, an unexplained fall.
NAUSEA AND VOMITING
More often in conjunction with vertigo.
Every stroke is different. The symptoms and effects vary according to the type of stroke, the part of the brain affected and the size of the damaged area. In some people the effects are severe and in some mild. Usually the symptoms come on suddenly but they may come on during sleep. Usually a stroke in one side of the brain causes the opposite side of the body to be affected.
Symptoms of Three Main Forms of Strokes
CEREBRAL INFARCTION (due to blockage of a blood vessel)
* Symptoms are as for warning strokes (TIA's) except that the changes are permanent.
CEREBRAL HAEMORRHAGE (due to rupture of blood vessel within the brain)
* Not usually proceeded by small warning episodes.
* Is usually a one-off development of weakness affecting one side of the body.
* If the left side of the brain is involved, speech is also affected.
* A depression in consciousness is a frequent accompaniment.
* The damage caused is usually greater than that of cerebral infarction and the mortality rate is higher.
* Similar symptoms to an infarction may be produced by the presence of a cerebral haemorrhage in either the left or right hemisphere or brain stem. Often the haemorrhage tends to have a more devastating effect than infarction with the resultant depression in consciousness, although with small haemorrhages excellent recovery is common.
SUBARACHNOID HAEMORRHAGE (due to rupture of blood vessel into the space surrounding the brain)
* This haemorrhage may be preceded by the sudden onset of an extremely severe headache, together with neck stiffness. Irritation from light may also be a problem.
* The headache usually arises all of a sudden (like a 'blow to the head'), and becomes the most intense headache the patient has ever felt within seconds.
* After minutes to hours the headache spreads to the back of the head, neck and back as blood tracks down the spinal subarachnoid space.
* The 30-40% of patients who lose consciousness immediately complain of headache within seconds to minutes of regaining consciousness.
* About 10% of patients suffer epileptic seizures.
* Nausea and vomiting re common at the outset.
Stroke is Preventable
While there is no cure for stroke, the chance of having a stroke can be reduced by early recognition, treatment and modification of the major risk factors: high blood pressure (hypertension), high cholesterol, smoking, diabetes and heart disease. Other risk factors include: excess alcohol, being overweight and lack of exercise. Everyone can reassess their life style and reduce the risk of stroke. Some key lifestyle changes that can be made include:
* Have your doctor check your blood pressure regularly
* Keep your cholesterol level within acceptable limits
* Don't smoke
* Check you don't have diabetes
* Avoid the combination of smoking and taking the contraceptive pill
* Avoid eating fatty or salty food
* Enjoy an active lifestyle
* Stay within your recommended weight/height range
* Balance work and leisure time.
Stroke Your Questions Answered, Prof Graeme J. Hankey, Churchill Livingstone, 2002
What is a Stroke, Prof Geoffrey A. Donnan, Brain Foundation (Victoria) Ltd.
Victorian Stroke Strategy October 1997