Seizures after stroke can appear within days or years after someone has come home from hospital. A convulsive seizure is alarming to watch, and the instinct to step in can push someone to take actions that actually make it worse. The people closest to a stroke survivor are the ones most likely to be in the room when a seizure starts, and they are rarely the ones with clinical training.
Strokes: Types and Risk Factors
A stroke happens when blood stops flowing to part of your brain. Brain tissue starved of oxygen dies within minutes, which is why every stroke is treated as an emergency from the first phone call. There are two main types of stroke. An ischaemic stroke is when a clot blocks an artery supplying the brain, and this is the most common type in Australia. A haemorrhagic stroke happens when a blood vessel bursts, and the blood escapes either into brain tissue or into the space around the brain. A transient ischaemic attack blocks the blood supply briefly and the symptoms clear within a short time, though it warns of a stroke to come.
More than 80 percent of seizures after stroke can be prevented. High blood pressure, an irregular heartbeat, high cholesterol, type 2 diabetes, smoking, heavy drinking, physical inactivity, and an unhealthy weight all increase your chance of a stroke. Older age, a previous stroke, and a family history of stroke also raise your risk of seizures after stroke.
How a Stroke Can Lead to Seizures
Seizures after stroke occur when the normal electrical activity of the brain is disrupted, which can change sensation, awareness, behaviour, or movement. A stroke destroys brain tissue, and the cells that survive around that damage no longer behave the way they did before. Epilepsy is one of the more common complications of stroke.
In the first days after an acute stroke, the injury disturbs the chemical balance in and around the damaged part of the brain, and cells there fire in sudden bursts. Breakdown products from the blood irritate the surface of the brain and add to that instability. Over the following months, scar tissue forms where brain cells died, and the connections between surviving neurons reorganise themselves. That rewiring leaves a lasting tendency towards seizures. The brain injury caused by a severe stroke can still be causing symptoms a year after stroke, long past the point where the survivor feels recovered.
Types of Poststroke Seizures
The International League Against Epilepsy sorts seizures after stroke into two categories by timing. Acute symptomatic seizures, also known as early-onset seizures, are seizures occurring within seven days of stroke onset, with the risk of one greatest in the first 24 hours. About 7 percent of stroke survivors have an early seizure.
A seizure more than seven days after the stroke is an unprovoked seizure, also called a late-onset seizure. An unprovoked seizure has about a 71.5 percent risk of recurrent seizures over the next ten years, which is high enough to meet the definition for post-stroke epilepsy.
Focal onset seizures may start in one part of the brain, and the person may remain conscious during it. A focal seizure can spread to both sides of the brain and become convulsive, while generalised seizures involve the whole body and can cause loss or major change in consciousness. Non-convulsive seizures involve reduced responsiveness, staring without answering, or confusion, sometimes with small repeated movements such as facial twitching. Status epilepticus is an epileptic seizure lasting five minutes or longer, or repeated seizure activity without break in between.
What a Seizure Looks Like
During a generalised convulsive seizure, the person’s muscles may stiffen suddenly, fall, and their head, arms, and legs can jerk. Their breathing may become shallow or stop briefly, drool, bite their tongue, and they may lose bladder or bowel control.
During a focal seizure, the person may jerk one part of their body. They may stay awake while feeling frightened or confused. Repetitive actions such as fiddling with clothing also count as seizure activity, and their awareness can range from fully alert through drowsy to unconscious.
Afterwards they may be dazed, confused, or drowsy for several minutes, and they may have no memory of what happened. Weakness can persist down one side of their body after seizure ends. Seizures after stroke need paramedics, so a face droop, arm weakness, or slurred speech is a reason to call triple zero without delay.
First Aid for a Seizure
First aid for seizures after stroke follows the same steps as first aid for any seizure. Your first decision is about breathing. If the person is unresponsive and not breathing normally, start CPR. Otherwise:
- Follow their seizure management plan if they have one.
- Ease their fall if you can.
- Move any objects that could injure them.
- Lay them down and put something soft and flat under their head.
- Time the seizure from the moment it started.
- Do not hold them down or put anything in their mouth.
Once their seizure stops, roll them into a side-lying recovery position and keep their airway clear if they are unresponsive but breathing normally. Otherwise, reassure them and let them rest where they are, since they may be dazed and frightened. Either way, keep checking their breathing, and give them nothing to eat or drink until they are fully awake and alert. Call an ambulance if:
- This is their first seizure, or nobody present knows whether they have had one before.
- The seizure lasts more than five minutes, or a second seizure starts.
- They do not regain consciousness within five minutes of the seizure stopping.
- The seizure happens in water.
- The person may be pregnant.
- You do not know the person.
- They don’t have a seizure action plan.
- They’ve had seizures before but this one appears different in any way.
- They injure themselves.
Seizure Action Plans
A seizure action plan is put together with the person’s doctor. It lays out the seizure types they have, their triggers, the point at which an ambulance is needed, and what to do before, during, and after a seizure. The plan should be reviewed at least once a year, or sooner if anything about their epilepsy or treatment changes. Where seizures after stroke continue, a current plan gives whoever is present a set of instructions to follow.
Where medication is prescribed, a separate emergency medication management plan covers the seizure type it applies to, and when and how to give the person their medication. Copies of both documents should be kept wherever the person spends time, including their workplace, their gym, any service supporting them, school, or sporting clubs.
Preparing as a Carer or Family Member
Anyone can respond to a seizure after stroke. Our nationally recognised first aid training leaves you able to position an unresponsive person, time a seizure accurately, and judge when to call triple zero without hesitating over what comes first. Enrolling now means that when a seizure starts, you already know what to do.
FAQs
Can You Develop Epilepsy from a Stroke?
Yes. Stroke is a leading cause of epilepsy in older adults, accounting for about 10 percent of epilepsy cases and roughly 55 percent of newly diagnosed seizures in that age group.
Is Medication Used to Prevent Seizures After a Stroke?
Not as a routine measure. Medication to prevent seizures is not recommended for stroke survivors who have not had one, because the risk of side effects in older people outweighs a low chance of benefit. Treatment starts after an unprovoked seizure, and lamotrigine and levetiracetam are reasonable first choices.
How Should Someone Avoid Driving After A Seizure?
The Australian standard allows a driver licensing authority to consider a conditional licence six months after a first seizure or an acute symptomatic seizure, provided no further seizure has happened and the treating doctor supports it.
