Stroke is defined as a specific area of neurological insufficiency due to a lesion in vascular system. Its onset is usually rapid and it may last for more than 24 hours. Patient may or may not survive during this episode. It presents as weakness of any area of body with or without disturbance of speech. It usually occurs after the age of 40 years. It is more common in males as compared to females. Its risk factors are non- modifiable which include age, gender, hereditary and previous history of stroke. Others are modifiable and include hypertension, cigarette smoking, diabetes, high blood cholesterol level and heart failure. Stroke is divided into two groups. One is hemorrhagic and other is ischemic stroke. There are 3 major categories of stroke: transient ischaemic attack, ischaemic stroke, and hemorrhagic stroke. It is claimed that 87 percent of strokes are ischemic.

Hemorrhagic Stroke

It occurs due to rupture of an artery. It has two types. One is intra-cerebral hemorrhage which occurs due to rupture of small arteries which are already weakened by hypertension. It can be fatal as compression of brain can occur. Second type is sub-arachnoid hemorrhage which develops due to rupture of major artery at the level of brain. This type of hemorrhage is characterized by sudden onset of headache, difficulty in movements of eyes, nausea and vomiting. History of patient who presents with stroke is important to determine the cause and progression of this disease.

Ischemic Stroke

Ischemic stroke occurs due to blockage of a major artery ultimately leading to decreased blood flow to the brain resulting in damage to brain cells which is called ‘cerebral infarction’. Arteries may be occluded due to thrombosis in intracranial or extra-cranial arteries or embolism from somewhere outside the brain especially heart. Once deprived of blood supply, brain tissues undergo sudden death within a few minutes. Damaged tissues are then filed up with fluid after some hours, which cause more damage and impair further blood flow.

Transient Ischemic Attack:

A transient ischemic attack (TIA) is a stroke that lasts just a few minutes. This occurs when the blood supply to part of the brain is temporarily blocked. TIA normally lasts just a few minutes and does not cause lasting damage. Approximately 1 in 3 people who have a transient ischemic attack will sooner or later have a stroke, with around half occurring within one year of a transient ischemic attack. A temporary ischemic attack can represent as both an alert and a chance to avoid a future stroke. Transient ischemic attacks normally last for a few minutes. Most signs and symptoms vanish within an hour, but they can sometimes last up to 24 hours. The signs and symptoms of TIA are similar to the ones early in the stroke that may include a sudden onset of: Slurred speech, vertigo, numbness or paralysis of face, arm or leg typically of side and blurred vision.

Difference of Hemorrhagic, Ischemic Stroke and Transient Ishemic Attack:                               

Cause:

Hemorrhagic stroke is caused by rupture of an artery.

Ischemic stroke is caused by blockage of a major artery.

In a transient ischemic attack, unlike with an ischemic stroke, the obstruction is brief and there is no lasting damage.

Etiology:

Hemorrhagic stroke is caused by hypertension.

Ischemic stroke is caused by high blood fat level.                        

Transient Ischemic Stroke could be due to atheroscelerosis(deposition of fatty material on the inner walls of aretries ),age,family history,high blood pressure.,cardiovascular disease and diabetes.

Terminology:                                                                                          

Hemorrhagic strokes are called ‘red strokes’.

Ischemic strokes are called ‘pale strokes’.

Transient Ischemic Stroke is commonly called as ‘mini-stroke’.

Frequency of occurrence:                             

Hemorrhagic strokes are less common in our country.

80 percent of stroke cases are ischemic stroke.

Transient Ischemic Attack occurs less than Ischemic Stroke.

Investigations:           

In hemorrhagic stroke, investigations of choice are CT scan, carotid Doppler, angiography and routine blood tests.

In ischemic stroke, investigations are ECG, Echocardiography, carotid Doppler, Magnetic Resonance Imaging (MRI), Computerized Tomography (CTscan) ,arteriography and other routine blood examination tests.

In Transient Ischemic Attack same above investigations are as followed.

Complications:  

Hemorrhagic stroke can cause spasm of arteries leading to decreased blood flow.

Ischemic stroke can progress into hemorrhagic stroke.

Transient Ischemic Attack may lead to an ischemic stroke. It can also cause brain swelling, visual field disturbance, and memory problems.

Education:

In hemorrhagic stroke, patient is counseled about his high blood pressure.

In ischemic stroke, patient is counseled about cardiovascular disease and its management.

In Transient Ischemic Attack we counsel patient for life style modification that includes stop smoking, reduce excess weight and minimize the intake of alcohol. Regulation of high blood pressure and high blood sugar level is even more essential.

Prognosis:            

In hemorrhagic stroke, there are better chances of recovery.

In ischemic stroke, chances of recovery are very less.      

In Transient Ischemic Attack, the prognosis is very good when treated with time.

Treatment:

Treatment of stroke includes proper assessment and diagnosis by the physician first about what type of stroke it is either hemorrhagic,ischemic or Transient Ischemic Attack . After that continue therapies to reduce the risk of getting a stroke. Essentially, this includes the use of antiplatelet drugs to reduce the risk of further clot formation. Acetylsalicylic acid * (ASA), ticlopidine, clopidogrel are medications that are widely used to thin blood, break up existing blood clots and prevent the development of blood clots. In exceptional cases, an anticoagulant medicine called warfarin or heparin may be recommended for the prevention of stroke. Other drugs such as blood pressure-reducing agents and cholesterol-reducing agents may be regarded to reduce the risk of a long-term stroke. Surgery for carotid artery blockages can be suggested for prevention of stroke if there is serious (more than 70%) blockage.

Mortality:

In hemorrhagic stroke, there is immediate mortality.

In ischemic stroke, rate of survival is better

In Transient Ischemic Attack survival rate is higher.

Conclusion

All of the above mentioned types of stroke are a major threat to life and require immediate treatment. However, TIA is less lethal but could be dangerous if not treated on time.  

https://www.mayoclinic.org/diseases-conditions/transient-ischemic-attack/symptoms-causes/syc-20355679

https://medbroadcast.com/condition/getcondition/transient-ischemic-attack

https://www.medscape.com