1.
Blood vessel separation.
Blood (arrow) flows freely
in both directions


2.
A blood clot has torn off
some other place and is
travelling. As the vessel
diameter is gretaer than
the clot blood still flows.


3.
The clot is stuck and the
area which is normally
oxygenated by this vessel 
will be affected.




4.
The clot dissolves after
a while and blood again
passes freely and the
lack of oxygen sypmtoms
dissapper.

Transient ischemic attack TIA (transient cerebral ischaemia) is a brief temporary (transient) interruption of the oxygen (ischemia) to the brain. Without adequate supply of oxygen to the brain tissue via the blood the brain cells cannot function and a reduction or cessation of blood flow in an area of the brain will therefore give symptoms in the corresponding part of the body. This can include paralysis of an arm or a leg and impairment of vision and speech.

It is important to distinguish between TIA and a stroke. The symptoms of the two diseases are similar, but TIA symptoms disappear within 24 hours. However, it is impossible to say which one of the diseases we are talking about when the symptoms start, and you should consult a doctor as soon as possible.

TIA is often desribed as mini stroke and can be a harbinger of a stroke, which perhaps can be prevented, and this is another reason to seek medical attention.

TIA is due mostly to a small blood clots from a narrow vein in the neck for example or because of arteriosclerosis affecting the small blood vessels in the brain or from a heart defect such as atrial fibrillation. The clot temporarily blocks the blood flow to an area of the brain. The clot dissolves quickly so blood can flow freely again and the patient's symptoms cease.

Symptoms of TIA - Transient ischemic attack

If symptoms persist less than 24 hours the condition will fall under TIA. In by far the most cases the symptoms only last minutes or a few hours. The symptoms arrive suddenly and may be: 

• Paralysis of an arm, a leg or half the face 
• Speech impairment, unintelligible speech or problems understanding 
• Tingling or numbness in parts of the body 
• Transient blindness of one eye 
• Dizziness, confusion 
• Balance and coordination problems 
• Other symptoms 

Precautions and diagnosis of TIA 

As mentioned TIA may be the sign of serious illness and persons experiencing any of the above mentioned symptoms should therefore seek medical attention right away. The doctor will carry out various examinations and studies to form a detailed diagnosis: 

• A CT scan of the brain (see image of the brain) would rule out the existence of a stroke 

• An electrocardiogram ECG will show whether atrial fibrillation is the cause of the symptoms 

• An ultrasound scan of the neck will show whether a narrow neck arterie may have released a small blood clot to the brain. 

Treatment and prevention of TIA -Transient ischemic attack

Blood thinners (aspirin) is normally given to prevent new clots from occurring. If atrial fibrillation is the reason stronger anti blood coagulation will be prescribed. If arteriosclerosis is the cause then an endarterectomy operation might be performed to remove the affected lining or a small tube can be inserted in the blood vessel to expand it.

As mentioned the underlying cause of TIA is usually arteriosclerosis. This process is accelerated by a number of life style risk factors that can be eliminated. This is done with quitting smoking and regular exercise. It is also important to lose weight, maintain a low alcohol intake and a healthy diet. Elevated cholesterol is an important risk factor, and even if the cholesterol level is not elevated, it can often be beneficial to lower it with diet change and medicine. If there is elevated blood pressure then blood pressure-lowering medication is prescribed. 

Complications and outlook of TIA

TIA is a common disease in the elderly, and in most cases the symptoms disappear without causing any harm. However one third of those being affected by TIA will later have a stroke. It is therefore important to have a diagnosis and take the necessary steps to prevent a future stroke.