The Differences Between a Stroke and a Seizure

The differences between a stroke and a seizure can be confusing. Both conditions involve the brain, may be characterized by problems controlling physical movements, are not uncommon, and involve unexpected brain episodes or "attacks."

They also each have a few different names, which can add to the difficulty. If you are not sure whether you or someone for whom you're a caregiver has had a seizure or a stroke, here are ways to understand some of the differences so that you will know what to expect.

Other Names for a Stroke

• Cerebrovascular accident (CVA)
• Cerebrovascular infarction
• Brain attack 
• Transient ischemic attack (TIA) or "mini-stroke," referring to a reversible stroke

Other Names for a Seizure

• Convulsions
• Brain attack 
• Brain spell 
• Brain fit
• Spasms 

Epilepsy is the correct name for the medical condition in which people are prone to repeated seizures.

What Is a Stroke?

A stroke is brain damage caused by interruption of blood supply to an area of the brain, either by a blockage of arteries (ischemic stroke) or by bleeding into brain tissue after a blood vessel ruptures (hemorrhagic stroke). When a region of the brain is damaged by a stroke, a person may lose some physical or mental ability that is normally controlled by the damaged region. The damage results from a lack of blood supply.

What Is a Seizure?

A seizure is a sudden surge of electrical activity in the brain that usually affects how a person appears or acts for a short time. It may cause uncontrollable physical movements or a change in consciousness.

Can a Stroke Turn Into a Seizure?

After a stroke, the damaged area of the brain forms scar tissue, and this tissue may begin sending out abnormal electrical signals. (Scar tissue from any cause can do this.) This electrical activity can trigger seizures based on its location and whether it spreads. So brain damage caused by a stroke may result in seizures down the road, and in some cases, epilepsy.

Can a Seizure Turn Into a Stroke?

In most cases, a seizure does not affect blood flow to the brain, and therefore a seizure does not cause a stroke. Some studies have been conducted, however, to determine whether seizures might be a sign of cerebrovascular disease or a higher risk of stroke.

Can a Stroke Result in Death?

About 11% of people who have a stroke do not survive. Death from a stroke is more likely when it is a large vessel stroke, when it affects the brainstem, or when it is a hemorrhagic stroke.

Can a Seizure Result in Death?

It is extremely rare for a seizure to cause death. However, a bodily injury that occurs during a seizure can result in serious injury or death. For example, if a person has a seizure while swimming, they could drown. If a person has a seizure while driving, they could get into an accident. If a person suffers a seizure and falls from a ladder, they may become severely injured.

There is also a rare condition called sudden, unexpected death of someone with epilepsy who was otherwise healthy, or SUDEP. In SUDEP cases, no other cause of death is found when an autopsy is done. Each year, about 1 in 1,000 people with epilepsy die from SUDEP. This is the leading cause of death in people with uncontrolled seizures.

Overdosing on anti-seizure medications can, in rare instances, cause death.

Medications for Stroke

Many medications are available to help prevent a stroke in people who have risk factors. Most stroke prevention medications are blood thinners.

No current medication can improve the brain damage caused by a stroke, although a great deal of research is focused on finding medications to help lessen the effects. However, occupational, physical, and speech rehabilitation can be very helpful in bringing back some of the function that was lost by the stroke.

A promising class of drugs called neuroprotectants may protect the brain from secondary injury caused by stroke; these drugs are in clinical trials in the United States.

Medications for Seizures

When a seizure occurs, nerve cells become unstable or overactive and conduct too much electricity, thereby activating nearby nerve cells and causing a cascade effect. The most common anti-seizure medications, typically called anticonvulsants, work by inhibiting or reducing the chemical processes that these nerve cells use to communicate.

Using alcohol or drugs while taking anticonvulsant medications can interfere with how they work and cause a seizure.

In patients who do not respond to medicine, surgery, or electrical stimulation tools, called neuromodulators, may be helpful.

What to Do If Someone Is Having a Stroke or a Seizure

If you think that someone may be having a stroke or a seizure, call 911 immediately and try to stay with the person until medical professionals arrive. It's helpful if you can describe everything you see to the emergency medical team. (If you cannot remember or describe it, don't worry; no one will blame you.)

The sooner people with a stroke get to the hospital, the better chance doctors have of saving valuable brain tissue. They may also receive crucial medications that could reverse some of the damage that may have happened from the stroke, but these need to be given quickly after the onset—so timing is key.

Unless you are a trained professional, do not try to move a person who may be having a stroke or a seizure. Do not try to give them medicine or put anything in their mouth. It is a good idea to move sharp or dangerous objects away from the person if you can.​​

Stroke and seizure are two conditions that people tend to confuse with one another. Most people who have had a stroke or seizures are able to lead healthy lives, but they will often need follow-up medical care.