Types of stroke

Depending on the cause, there are several types of strokes. Your HonorHealth neurologist will examine and test you carefully to determine which type of stroke you may be experiencing:

Ischemic: The majority (87 percent) of all strokes, they occur where a blood clot in a blood vessel blocks the flow of blood to the brain, cutting off the supply of oxygen and nutrients.

Ischemic strokes can be embolic or thrombotic. Embolic are caused by a clot that migrated from another part of the body. Thrombotic are caused by a clot that forms at the obstructed site. The underlying cause of this obstruction is the development of fatty deposits called atherosclerosis lining the vessel wall.

Both types result in decreased blood flow to vital brain cells, which can lead to irreversible cell death and long-term disability. Watch for signs for the sudden onset of ischemic stroke.

Many ischemic stroke symptoms show similarities with hemorrhagic stroke symptoms.

Hemorrhagic: Accounting for 13 percent of stroke cases, this type occurs when a blood vessel breaks, leaking blood into the brain. The blood then accumulates and compresses the surrounding brain tissue. This results in a stroke by depriving parts of the brain of blood and oxygen. You may feel a headache when this occurs.

This type of stroke often is caused by high blood pressure, which stresses artery walls to a breaking point. The brain is highly sensitive to the presence of leaking blood and responds by swelling. Likewise, leaked blood can shift brain tissue against the skull. Either way, pressure builds within the skull. Watch for the sudden onset of hemorrhagic stroke. There are two kinds of hemorrhagic stroke:

  1. Intracerebral hemorrhage is the most common type and occurs when a diseased blood vessel within the brain bursts and allows blood to leak within the brain. This causes increased pressure within the brain, damaging the brain cells surrounding the blood. Hypertension is the main cause of this condition. Risk factors include alcohol and drug abuse, increased age, taking medications called blood thinners, being male and being African American.
  2. Subarachnoid hemorrhage occurs when a blood vessel just outside of the brain ruptures. This causes the area of the skull surrounding the brain to rapidly fill with blood. It's usually caused when an aneurysm swells, weakens the vessel and ruptures. Risk factors include middle age, family history, smoking, excessive alcohol use, being female and being African American.

A sudden, severe headache or an unusual headache may result. Simultaneously, other signs of hemorrhagic stroke include stiff neck, facial pain, pain between the eyes, vomiting or altered consciousness.

Hemorrhagic stroke symptoms include the sudden onset of:

  • Weakness or inability to move a body part.
  • Drowsiness, stupor, lethargy or confusion.
  • Loss of sensation.
  • Decreased or lost vision (may be partial).
  • Speech difficulties and inability to discern familiar objects.
  • Dizziness, vertigo (sensation of the world spinning around) and loss of coordination.
  • Facial droop and/or difficulty swallowing.
Types of stroke

Transient ischemic attack (TIA): Also known as a ministroke, this incident causes you to experience symptoms similar to those of a stroke. The cause of a transient ischemic attack is a temporary decrease in blood supply to part of your brain. Most attacks last just a few minutes.

TIA has the same cause as an ischemic stroke — a clot blocks the blood supply to part of the brain. A TIA doesn't leave lasting effects to your brain. But if you've had a TIA, it means you probably have a blocked or narrowed artery leading to your brain, putting you at a greater risk of a full-blown stroke that could cause more permanent damage. If you're having a TIA, get emergency medical treatment and make sure your family physician knows about it. Watch for signs for the sudden onset of a TIA.

Aneurysm: An aneurysm is an abnormal widening or ballooning of a weakened area in the wall of a blood vessel. When an aneurysm occurs in the brain, it’s called a cerebral aneurysm. It may be present from birth, or it may develop later in life after a blood vessel is injured. There are many different types of aneurysms. These typically cause unexplained headaches until they burst. Once ruptured, a stroke occurs. Watch for signs for the sudden onset of ischemic stroke.

Arteriovenous malformation: This abnormal connection usually forms before birth between the arteries and veins in the brain. The most common symptom is a seizure or a hemorrhagic stroke. The condition occurs when arteries in the brain connect directly to nearby veins without having the normal vessels, capillaries, between them. Cerebral arteriovenous malformations occur in less than 1 percent of people. Watch for signs for the sudden onset of ischemic stroke.