Stroke

Overview of Stroke

A stroke occurs when the blood supply to part of your brain is interrupted or reduced, preventing brain tissue from getting oxygen and nutrients. Brain cells begin to die in minutes.

 

A population-based study conducted in 2011 shows that compared with patients in the comparison cohort, patients with traumatic brain injury had significantly higher stroke rates within the 3-month (2.91% versus 0.30%), 1-year (4.17% versus 0.96%), and 5-year (8.20% versus 3.89%) periods after index use of health care services.

Symptoms of Stroke

  • Trouble speaking and understanding what others are saying. You may experience confusion, slur your words or have difficulty understanding speech.

  • Paralysis or numbness of the face, arm, or leg. You may develop sudden numbness, weakness or paralysis in your face, arm, or leg. This often affects just one side of your body. Try to raise both your arms over your head at the same time. If one arm begins to fall, you may be having a stroke. Also, one side of your mouth may droop when you try to smile.

  • Problems seeing in one or both eyes. You may suddenly have blurred or blackened vision in one or both eyes, or you may see double.

  • Headache. A sudden, severe headache, which may be accompanied by vomiting, dizziness or altered consciousness.

  • Trouble walking. You may stumble or lose your balance. You may also have sudden dizziness or a loss of coordination.

Causes of Stroke

A blocked artery (ischemic stroke) or leaking or bursting of a blood vessel (hemorrhagic stroke).

Ischemic Stroke

This is the most common type of stroke. It happens when the brain's blood vessels become narrowed or blocked by fatty deposits that build up in blood vessels or by blood clots or other debris.

 

The two most common types of ischemic strokes are thrombotic and embolic. A thrombotic stroke happens when a blood clot forms in one of the arteries supplying blood to the brain. The clot passes through the bloodstream and becomes lodged, which blocks blood flow. An embolic stroke is when a blood clot or other debris forms in another part of the body and then travels to the brain.

Some initial research shows that COVID-19 infection may be a possible cause of ischemic stroke, but more study is needed.

 

Transient Ischemic Attack (TIA) or Ministroke

A TIA occurs when blood flow to the brain is blocked temporarily, usually by a blood clot. Symptoms, which are similar to those of a full stroke, are typically temporary and disappear after a few minutes or hours. It serves as a warning of a future stroke, so don’t ignore a TIA.

 

Hemorrhagic Stroke

A hemorrhagic stroke happens when an artery in the brain breaks open or leaks blood. The blood from that artery creates excess pressure in the skull and swells the brain, damaging brain cells, and tissues.

 

The two types of hemorrhagic strokes are intracerebral and subarachnoid. An intracerebral hemorrhagic stroke, the most common type of hemorrhagic stroke, happens when the tissues surrounding the brain fill with blood after an artery burst. Subarachnoid hemorrhagic stroke is less common. It causes bleeding in the area between the brain and the tissues that cover it.

 

Risk Factors of Stroke

Lifestyle

  • Being overweight or obese

  • Physical inactivity

  • Heavy or binge drinking

  • Use of illegal drugs such as cocaine and methamphetamine

Medical

  • High blood pressure

  • Cigarette smoking or secondhand smoke exposure

  • High cholesterol

  • Diabetes

  • Obstructive sleep apnea

  • Cardiovascular disease, including heart failure, heart defects, heart infection or abnormal heart rhythm, such as atrial fibrillation

  • Personal or family history of stroke, heart attack or transient ischemic attack

  • COVID-19 infection

Personal Background

  • Age — People age 55 or older have a higher risk of stroke than do younger people.

  • Race — African Americans have a higher risk of stroke than do people of other races.

  • Sex — Men have a higher risk of stroke than women. Women are usually older when they have strokes, and they're more likely to die of strokes than are men.

  • Hormones — Use of birth control pills or hormone therapies that include estrogen increases risk.

 

Treatments of Stroke

Ischemic stroke and TIA

Antiplatelet and anticoagulants

Over-the-counter aspirin is often the first line of defense against stroke damage. Anticoagulant and antiplatelet drugs should be taken within 24 to 48 hours after stroke symptoms begin to prevent clotting.

 

Clot-breaking drugs

Thrombolytic drugs can break up blood clots in the brain’s arteries, which still stop the stroke and reduce damage to the brain.

 

One such drug, tissue plasminogen activator (tPA), or Alteplase IV r-tPA, is considered the gold standard in ischemic stroke treatment. It works by dissolving blood clots quickly if delivered within the first 3 to 4.5 hours after symptoms of stroke began. People who receive a tPA injection are more likely to recover from a stroke, and less likely to have any lasting disability as a result of the stroke.

 

Stents

If the doctor finds where artery walls have weakened, they may perform a procedure to inflate the narrowed artery and support the walls of the artery with a stent.

 

Surgery

In the rare instances that other treatments don’t work, the patient's doctor may perform surgery to remove a blood clot and plaques from the patient's arteries. One surgery is mechanical thrombectomy. During which the doctor inserts a catheter into a large blood vessel inside the patient's head. They then use a device to pull the clot out of the vessel. This surgery is most successful if it’s performed 6 to 24 hours after the stroke begins. If the clot is especially large, the doctor may open an artery to remove the blockage.

 

Hemorrhagic stroke

Medications

Unlike with an ischemic stroke, if the patient is having a hemorrhagic stroke, the treatment goal is to make the blood clot. Therefore, patients may be given medication to counteract any blood thinners the patient takes.

 

The patient may also be prescribed drugs that can reduce blood pressure, lower the pressure in the brain, prevent seizures, and prevent blood vessel constriction.

Coiling

During this procedure, the doctor guides a long tube to the area of hemorrhage or weakened blood vessel. They then install a coil-like device in the area where the artery wall is weak. This blocks blood flow to the area, reducing bleeding.

 

Clamping

During imaging tests, the doctor may discover an aneurysm, which is a weakening of an artery wall that creates a bulge or distension of the artery, that hasn’t started bleeding yet or has stopped. To prevent additional bleeding, a surgeon may place a tiny clamp at the base of the aneurysm. This cuts off blood supply and prevents a possible broken blood vessel or new bleeding.

 

Surgery

If the doctor sees that an aneurysm has burst, they may do surgery to clip the aneurysm and prevent additional bleeding.

 

Prevention of Stroke

  • Quit smoking

  • Consume alcohol in moderation: Heavy alcohol consumption increases your risk of high blood pressure and strokes and may also interact with drugs that you are taking. However, drinking small to moderate amounts of alcohol may help prevent ischemic stroke

  • Maintain a healthy weight

  • Exercising regularly

  • Eating a diet rich in fruits and vegetables: Eating less cholesterol and fat may reduce the buildup in your arteries.

 

 

References:

“Stroke - Symptoms and Causes.” Mayo Clinic, 9 Feb. 2021, www.mayoclinic.org/diseases-conditions/stroke/symptoms-causes/syc-20350113#:%7E:text=A%20stroke%20occurs%20when%20the,and%20prompt%20treatment%20is%20crucial.

“Everything You Need to Know About Stroke.” Healthline, 16 Oct. 2019, www.healthline.com/health/stroke.

Chen, Yi-Hua, et al. “Patients With Traumatic Brain Injury.” Stroke, vol. 42, no. 10, 2011, pp. 2733–39. Crossref, doi:10.1161/strokeaha.111.620112.

Resources by Judy Zhu