Stroke

What is Stroke?

A stroke is a medical emergency causing neurological injury to the brain due to ischemia or hemorrhage. Ischemia to the brain means a portion of the brain is not receiving blood and oxygen. Hemorrhage means there is bleeding in the brain due to a ruptured blood vessel.

A stroke is due to a cardiovascular cause, yet causes neurological disorders. A stroke is a medical emergency.

What are the types?

The two types of stroke include:

  • Ischemic stroke- more common (80%)
    • Blockage of blood supply to an area of the brain
  • Hemorrhagic stroke – less common (20%)
    • Bleeding into the brain from a burst bleed vessel

How does it occur?

A stroke occurs when blood flow to the brain stops for more than a few seconds depriving the brain of oxygen. Without oxygen for an extended period of time, permanent brain damage can occur.

Ischemic stroke may occur due to blocked or clogged arteries. A blocked artery can be due to a blood clot. A blood clot may form in an already narrowed artery (thrombotic stroke). A clot may also dislodge from another site of the body and travel to the brain (embolic stroke). Clogged arteries are due to a collection of fat, cholesterol, calcium and other substances in the interior wall of an artery.

A hemorrhagic stroke occurs in weak vessels which can rupture causing blood to leak into the brain. (i.e. aneurysm)

What are the risk factors?

A number of risk factors are present for stroke.
 
These factors include:
 
  • High blood pressure* (number one risk factor)
  • Increasing age (>55)
  • Family history of stroke
  • Race (African Americans are at a higher risk)
  • Diabetes
  • High cholesterol
  • Atrial fibrillation
  • Peripheral vascular disease
  • Oral contraceptives (birth control pills)
Precipitating factors:
 
  • Obesity
  • Heavy drinking
  • Eating high amounts of cholesterol or salt
  • Substance or drug abuse

What are the symptoms?

Stroke symptoms depend on what part of the brain has suffered from the lack of blood supply. Some people may be asymptomatic and may never know they have had a stroke.
 
Symptoms usually occur suddenly without any warning and can even occur while you are sleeping.
 
Symptoms are typically more severe when the stroke first happens, but can get worse.
 
Hemorrhagic stroke symptoms (bleeding within the brain) typically appear with a sudden and severe headache that can happen when lying down or while sleeping. The headache can get worse while straining, coughing, or with change of position.
 
Other symptoms of stroke include:
 
  • Change in alertness
  • Change in hearing
  • Change in taste
  • Change in the perception of touch, pain, pressure, and/or temperature
  • Difficulty in swallowing, speaking, reading, writing
  • Vision disturbances
  • Loss of coordination
  • Muscle weakness in face, arm, leg (usually on one side)
  • Tingling or numbness on one side of the body
  • Difficulty in walking
  • Loss of balance
  • Clumsiness
  • Confusion/ loss of memory
  • Change in mood, personality, or emotional changes

What are the complications?

A number of complications may occur with stroke. A stroke can cause temporary or permanent disabilities, depending on how long the brain has suffered without oxygen and which part of the brain was affected.
 
Common complications include the following:
 
  • Loss of movement or feeling in one or more parts of the body
  • Loss of mobility
  • Blood clots
  • Difficulty eating and drinking, which increases the chance of pneumonia and malnutrition
  • Difficulty in speech
  • Seizures
  • Urinary tract infection
  • Bleeding in the digestive system
  • Heart attack or heart failure
  • Cardiac arrhythmia
  • Bed sores
  • Falls
  • Dementia or thinking difficulties
  • Change in behavior
  • Death

How is a stroke diagnosed?

  • F – Facial Drooping
  • A – Arm Weakness
  • S – Speech Difficulty
  • T – Time to call 911
Anyone who has signs or symptoms of stroke needs immediate medical attention in an emergency department or hospital.
 
Several tests may be used to determine your risk of stroke including:
 
  • History & Physical Examination: Your doctor will ask you or a family member what symptoms you have been having, when they started, what you were doing when they began and if these symptoms are still present. Your doctor may ask you what medications you take and whether you have experienced any head injuries. You will be asked about your personal and family history of heart disease, TIA or stroke.
Your doctor will check your blood pressure and listen to your heart sounds and for any swooshing (bruit) sound over your carotid arteries in your neck, which may indicate atherosclerosis. An eye examination may be done using an ophthalmoscope to look for cholesterol crystals of clots in the back of your eyes.
 
  • Blood Tests: Important tests will be ordered to see how fast your blood clots along will blood sugar levels, presence of infection, and other critical elements of blood.
  • Computerized Tomography (CT) scan: Brain imaging is a key role in determining the presence of stroke and confirm the type of stroke. A CT scan uses a series of x-rays to create detailed images of your brain and the surrounding blood vessels of the head and neck.
A CT scan can reveal brain hemorrhage, tumors, strokes, and other conditions.
 
Doctors may inject a dye into your blood vessels to view your blood vessels for more detail known as a CT angiography.
 
  • Magnetic Resonance Imaging (MRI): Uses radio waves and magnets to create a detailed image of your brain.
  • Carotid Ultrasound: A noninvasive test using sound waves are used to determine fatty deposits (plaques) and quality of blood flow in your carotid arteries.
  • Angiogram: Your doctor inserts a thin flexible tube (catheter) through a small incision in the groin and advanced up to the carotid arteries under x-ray guidance with the use of a dye to visualize the arteries.
  • Echocardiogram (ECHO)– a noninvasive test using sound waves to determine the size and function of the heart’s chambers and the structure and function of the heart valves.
  • Loop Recorder: for cryptogenic stroke or TIA; this is a device that is implanted into the chest which detects irregular heart rhythms (i.e. atrial fibrillations).

How is it treated?

A stroke is a medical emergency. Immediate treatment can save lives and reduce disability.
 
Call 911 or seek urgent medical care at the first sign of a stroke.
 
 
 
Ischemic Stroke
 
The goal of treatment in ischemic stroke is to restore blood flow to the affected area of the brain as quickly as possible.
 
Medicines used for the early treatment of stroke are used to break down clots (i.e. aspirin, anticoagulants, etc).
 
Results are best seen within the first 3 hours of symptoms.
 
  • Mechanical removal of the clot can be done with the insertion of a catheter into an artery of the brain and removing the clot.
  • Some patients benefit from an injection into the vein of tissue plasminogen activator (TPA) which dissolves the blood clot causing a stroke. TPA can also be administered directly into the brain with the use of a catheter threaded into an artery of the brain where the stroke is occurring.
  • Carotid Endarterectomy: is a procedure where a surgeon removes the fatty plaque from the carotid arteries in the neck that lead to the brain. This decreases the risk of having stroke again.
  • Angioplasty and stent: Angioplasty is the stretching of an artery with a balloon to widen it, followed by stent placement. The physician inserts a long, thin tube (catheter) into the narrowed part of your artery. A wire with a deflated balloon is passed through the catheter to the narrow area. The balloon is then inflated, compressing the plaque against the artery walls so it no longer restricts blood flow. Following this a stent may be placed to prevent restenosis.
 
 
Hemorrhagic stroke
 
The treatment of a hemorrhagic stroke depends on the cause of bleeding (i.e. high blood pressure, use of anticoagulant medications, head trauma, blood vessel malformation).
 
  • The initial treatment is to first determine the cause of bleeding
  • Control the blood pressure
  • Stopping any medication that could increase bleeding. (If stroke is due to hemorrhage (bleeding), clot-breaking drugs (thrombolytics) can cause more bleeding)
  • Transfusion of clotting factors may be given to stop ongoing bleeding
  • Measuring and controlling the pressure within the brain
Surgical blood vessel repair may be needed in cases of aneurysms or arteriovenous malformation (AVM) rupture.
 
Surgical options include:
 
  • Surgical clipping: The surgeon places a clamp at the base of the aneurysm and stops blood flow to it.
  • Coiling (endovascular embolization): The surgeon guides a detachable coil into the aneurysm and fills the aneurysm with the coil. This blocks blood flow into the aneurysm and causes the blood to clot.
  • Surgical AVM removal: The surgeon removes the AVM if possible, to eliminate the risk of rupture and lower the risk of a hemorrhagic stroke.
  • Decompressive craniotomy: When a patient’s life is threatened due to the high pressure effects of a clot in the brain, the physician may open the skull and/or remove the blood.
Once the bleeding within the brain stops, treatment usually involves bed rest and supportive medical care.

What is the prognosis?

The outlook depends on:
 
  • The type of stroke
  • How much brain tissue is damaged
  • What body functions have been affected
  • How quickly you get treated
Some patients may recover completely or some may remain with permanent loss of function.
 
Over half of the patients are able to function and live at home. Others may not be able to care for themselves.
 
If treatment with clot dissolving drugs is successful, the symptoms of stroke may go away. However, patients who do not receive treatment soon enough may not get the same results.
 
Patients who have ischemic stroke (due to blood clot) have a better chance of surviving than those with hemorrhagic stroke (bleeding).
 
Risk of a second stroke is highest during the weeks or months after the initial stroke.

How can I prevent this?

Know your stroke risk factors. Identifying your risk factors makes prevention of stroke easier.
 
Follow your doctor’s recommendations and adopt a healthy lifestyle.
 
Some lifestyle recommendations include:
 
  • Controlling high blood pressure
  • Lowering the amount of cholesterol and saturated fat in your diet
  • No smoking
  • Control diabetes (high sugar levels)
  • Maintain a healthy body weight with a BMI <25
  • Eat a diet rich in fruits and vegetables
  • Exercise regularly
  • Drink alcohol in moderation, if at all
  • Treat obstructive sleep apnea, if present
  • Reduce stress
*Ask your doctor about taking low dose aspirin!
 
Taking a small dose of aspirin thins the blood and helps prevent blood from clotting.