Transient ischemic attack
Definition
Transient ischemic attack is an episode of stroke like symptoms for few minutes to 24 hours, usually for 1-2 hours.
Alternative names
TIA, Mini stroke, Little stroke
Causes, incidence and risk factors
Transient ischemic attack is caused due to temporary disturbance in supply of blood to brain which results in sudden decrease in brain function for a short period of time.
The symptoms of transient ischemic attack are for short period of time as compared to stroke and no changes are seen on CT scan or MRI in contrast to stroke. The disturbance in supply of blood can be caused due to clot in blood in artery supplying blood to the brain; the clot that moves from other part of the body to the brain; constriction of the blood vessel to the brain or in the brain or damage to blood vessel.
Rare causes of transient ischemic attack are: blood disorders like sickle cell anemia, polycythemia, syndromes causing thick blood; conditions causing problems of blood vessels like systemic lupus erythematosus, syphilis and fibromuscular dysplasia; inflammation of the arteries like arteritis, polyarteritis and granulomatous anginitis; irregular heart rhythm and spasm of the brain arteries.
Artheresclerosis, high blood pressure, heart disease, diabetes, increasing age, migraine headaches and smoking are the risk factors for transient ischemic attack.
Symptoms
Symptoms of transient ischemic attack are similar to stroke symptoms but for shorter duration. They are numbness, tingling, loss of sensation, feeling of surrounding is moving (vertigo), weakness, speech difficulty, vision changes (decreased vision, double vision or loss of vision), eye pain, loss of balance, gait changes, staggering, weakness in legs, confusion and facial paralysis. The symptoms are sudden and last only for few minutes to 24 hours. The symptoms may reoccur and occur on the same side of the body.
Signs and tests
The condition is diagnosed on the basis of medical history ad physical examination. Neurological examination during the episode of transient ischemic attack may be abnormal but it returns to normal after the episode passes away. Blood pressure may become low before the onset of symptoms.
The tests done to diagnose transient ischemic attack are complete blood count, blood clotting tests, electrocardiogram, head CT scan, cranial MRI, cerebral arteriogram and carotid duplex. Additional tests are blood glucose, blood chemistry, serum lipids, erythrocyte sedimentation rate, chest X-ray and tests for syphilis.
Treatment
The treatment is aimed at improving blood supply to brain and to prevent the recurrence of the condition. Treatment is given depending on the cause. Blood thinners and surgery for the clogged neck the arteries are some of the treatments. Quitting smoking and low fat and low salt diet are some of the lifestyle modifications required.
Expectations (Prognosis)
The condition is for short period of time and there is complete recovery. There may be recurrence of episode at any time or a stroke attack. The condition should be treated aggressively as that of stroke because any transient ischemic attack can develop into stroke.
Complications
Injury due to falls, stroke and death of brain cells due to inadequate blood supply are the possible complications of transient ischemic attack.
Calling your health care provide
If there are symptoms of transient ischemic attack then it should be treated as medical emergency and no case should be left untreated (even though it has recovered) as it can cause stroke in future.
Prevention
Controlling the risk factors like high blood pressure, heart disease, diabetes, smoking, aspirin/heparin/warfarin therapy and carotid endarterectomy can prevent transient ischemic attack.
Reference
Nih.gov, wikipedia.com