What is the link between seizures and dementia?

There are some symptoms of dementia that are more commonly known, such as memory loss. Seizures are a less common symptom of dementia that are not as understood. Hear from one of our dementia researchers who has been studying seizures in people with the condition.

How common are epileptic seizures in dementia? Who is most at risk of having them? What do these seizures look like? What effect do they have on how someone’s memory changes over time?

These are the questions that I have been researching since starting my PhD in 2016. I'm a student funded by Alzheimer’s Society as part of the University of Exeter doctoral training centre.

What do we know about seizures and dementia?

People with dementia are at risk of having epileptic seizures. We’ve known this for a long time – it was described by Alzheimer himself in 1911.

However, how common they are remains unclear. This is because epileptic seizures can often be subtle. 

There are two common types of epileptic seizures:

Generalised tonic-clonic seizures

Most of us are familiar with the kind of epileptic seizures we see on TV or in films. People become unresponsive, they fall to the ground, become stiff and their whole-body shakes in a convulsion.

Generalised tonic-clonic seizures are hard to miss. But this is not what most epileptic seizures look like. 

Focal onset seizures

Most epileptic seizures in people with dementia are known as focal onset seizures. These can involve brief periods of increased amnesia or unresponsiveness. We see involuntary repeating movements, often of the hands and arms, or of the face (chewing, lip-smacking or swallowing).

Understandably, the latter are more easily missed, especially as the person affected will often quickly be back to normal afterwards.

Who might be affected by seizures?

For a long time, researchers believed epileptic seizures occurred only in people who had long been diagnosed with dementia. It was thought they were a reflection of how much the brain had changed and shrunk because of it. 

However, more recent research has suggested that seizures can occur early-on in Alzheimer’s disease. In some people, seizures may happen even before memory problems become apparent.

As part of my research, I recruited people from the local memory clinic here in Exeter. We asked them questions about epilepsy.

It quickly became clear that most people don’t know that having dementia, particularly Alzheimer’s disease, can increase your risk of seizures.

In our group, around 1 in 8 patients with dementia described episodes which we believe could have been epileptic seizures.

We interviewed our participants one year later and found that those who had described having had epileptic seizures previously performed less well on memory tests than those who showed no evidence of epilepsy. 

Why do people with dementia develop seizures? 

Ultimately, anything that changes the structure of the brain can cause seizures. 

This happens for some people after a stroke, a head injury, or with a brain infection like meningitis. A similar problem is happening in the brain in dementia. As cells in the brain die and the brain shrinks this can lead to epilepsy. 

In addition, we know that two proteins that build up in the brain of people with Alzheimer’s disease – amyloid and tau – affect how the brain’s nerve cells communicate with each other.

Sometimes these nerve cells can become 'hyper-excitable', meaning they can behave uncontrollably, causing epileptic seizures.

Can seizures be managed in people with dementia?

There is good news. There are medicines that are effective at reducing, and hopefully stopping, epileptic seizures.  

If you think that you or someone you know with dementia may be having epileptic seizures, you should tell a doctor. They might want to perform some extra tests and may want to start some extra medicines to treat this problem. 

What we don’t know yet is whether starting treatment for epilepsy might help to slow down dementia and whether it might help keep people’s memory function better for longer.

When is anti-seizure medication typically prescribed?

Anyone can have an epileptic seizure, but most people who have a single seizure will not have any more. As a result, doctors do not usually prescribe anti-seizure medicines in someone after a single seizure.  

While they can be distressing to witness, people who have a seizure typically return to their normal selves soon afterward with no long-term effects. 

However, doctors are likely to look for causes as for why a single seizure may have happened.  

In people with dementia, the fact that they have dementia can be the ‘why’, but other causes should also be considered – including stroke, head injury, and infections.

If someone has a second seizure it suggests they have epilepsy, so starting anti-seizure treatments would be appropriate. Usually this involves a discussion with a neurologist to see which treatment option is most suitable. 

However, telling the difference between single and multiple seizures isn’t always as straightforward as it sounds. For example, if someone has multiple seizures over a few hours (without complete recovery between them) this can still count as a single seizure.  

If someone is having a prolonged seizure (where the person is unresponsive for five minutes or more) it’s likely that doctors would want to administer emergency treatments – usually an injection – to stop the seizure from continuing.

This treatment is important, as seizures can affect someone’s breathing as well as their heartbeat.  

Sometimes people with prolonged seizures may need to be admitted to intensive care to keep them physically stable while they recover.

Why might a person with dementia not be prescribed anti-seizure medication?

If a person living with dementia has a single seizure, doctors may decide not to prescribe an anti-seizure medicine – even though having dementia means the person has a higher risk of having further seizures.

There can be several reasons for this. Some doctors may be concerned that starting an anti-seizure medicine could interfere with other important medicines that the person is already taking.

Others may be concerned that an anti-seizure medicine could cause side effects or make dementia symptoms worse.  

Sometimes, however, starting an anti-seizure medicine may actually help a person’s dementia – at least over the long-term. This is because people who have more seizures in dementia tend to have a faster rate of cognitive decline, so preventing further seizures with medicines may stop this accelerated decline.

Newer anti-seizure medicines are also less likely to interfere with other medications or cause side effects.

This article was first published in 2019 and most recently updated in September 2022.

Support dementia research

Alzheimer’s Society is working tirelessly to challenge perceptions, fund research and improve care and support. We rely on your donations. Let’s take on dementia together.

Donate today


I've been taken care of by a top Epilepsy team for 7 years now and have a vagus nerve stimulator fitted. It records upwards of 100 focal seizures per day regardless of medications. Meanwhile, my symptoms fit with Frontotemporal Dementia, my Mother died from FTD, and my 72 hr EEG showed that most of the discharges were from the Frontal Lobe. I have bilateral hippocampal sclerosis. So. What do I do? Is it FTD like my Mother or simply epilepsy (meaning they don't know the cause)?

Hi Michael,

We'd recommend speaking to your GP or local health provider about your concerns.

If you have any questions, please call our support line on 0333 150 3456, where you can speak with one of our trained dementia advisors. They will listen to you and be able to provide information and advice that's specific to your situation. More details of the support line (including opening hours) are available here: https://www.alzheimers.org.uk/dementia-connect-support-line


We hope this helps.

Alzheimer's Society web team

Hi there people I hope you all are doing well plz God, anyways I will keep this short as possible... One night I was coming home with my then girlfriend she said I took a seizure of some kind I was taken to hospital for an M.R.I ECT... But it was afterwards that was a complete nightmare, I had a 30 second memory for about 6 mts , so like everyday I would have to be told that mam n dad were both Dead along with a lot of my friends because I would be on my way to call into some of my friends so it was like living there death over n over every day plus I missed a Court day and had to go in for 9 mts witch actually was great for my mental health simply because you do the same thing ever day witch is nothing but it stableised my memory... Lord really does work in misterious ways,, it's now at about two or three days instead of 4-5 muinets... God bless you all ❤️ and any advice on anything would be great thanks for reading this 🙏
Can someone please describe these seizures to me? My grandfather has Alzheimer's, and he experiences "fits" on a daily. He begins making strange noises as if he has shortness of breath, and once the "fit" is over, he has no idea it even happened. He's completely spaced out. Does this sound familiar?

Hi Caleigh, we're sorry to hear about your grandfather. That sounds like a worrying situation for you both.

We'd recommend speaking to your GP or local health provider. Please know we're also here to support you. You can call our support line on 0333 150 3456, where you can speak with one of our trained dementia advisors. They will listen to you and be able to provide dementia information and advice that's specific to your situation. More details of the support line (including opening hours) are available here: https://www.alzheimers.org.uk/dementia-connect-support-line

We hope this helps for now Caleigh, please do call our support line.

Alzheimer's Society web team

I've noticed over the last two nights that busy conversation and bright light have triggered partial focal seizures. In busy situations, I lose focus. I then feel a strong urge to remove myself from the situation. I'll need some caloric intake. And then I need sleep.
My husband has Alzheimer’s and we are currently in emerg for his third seizure. Why has no one told me that this could be the cause. They send you home with a diagnosis but no information or follow up.
My mam was diagnosed with alzheimers 11 years ago but we noticed signs about 5 years before that, she is 76 now and has had seizures for the last ten years, before reading this I knew nobody else who had seizures with alzheimers, nothing to add really just it's been a very long horrible road
Ronnie, I feel for you. My Mom has struggled with dementia since at least 2015, and she had epileptic seizures for years before neurology added medical management which has controlled them and given her a happier life. I am still befuddled as to why it took so long for treatment. A long and overly winding road to help for her. It affected my career and my father's health along the way, as these things have ripple effects. I am sorry you've had a rough time but know that there are others out there too with related experiences, and things CAN improve. Best to you and your family.
My 85 year old mum was diagnosed with Vascular dementia just over a year ago and has been living well, independently around the house, excellent personal care and can make simple breakfasts and lunches (she just can't drive so is isolated). My brother has moved in with her and cooks an evening meal. at 7am on sunday he found her lying on the bed, unresponsive and called the ambulance. At hospital is was discovered she had broken and dislocated her shoulder. no signs of bruises or cuts or a fall. She doesn't remember anything. A CT scan shows no sign of a stroke. the dr's think it might be a seizure. How is it she didn't feel the pain of the break?
My BIL has frontal lobe dementia - for yrs. This a.m. his wife went to take his shirt off over his head and screamed, arms and fist rigid and then fell to floor. He was turning blue/purple. Caregiver started CPR and had come to whem EMS arrived. EKG fine, no changes in brain, no stroke. Said seizure due to his FLD. Why would he turn blue/purple and have to have CPR?

Hi Debbie, we're really sorry to hear this. We hope your BIL's situation is improving and that he's receiving all the medical support and care that he needs. It sounds like it was a stressful experience for you all.

Unfortunately, we don’t know enough about your BIL's medical history or situation to be able to provide an accurate answer. We would recommend that you speak directly with a medical professional, such as your local health provider, about this. They may hopefully be able to provide more information and advice.

More generally, you may also benefit from talking with other people who have gone through or are going through similar experiences within our online community, Talking Point: https://forum.alzheimers.org.uk/ - the forum is free to use, and open day or night.

You can also call our support line on 0333 150 3456, where one of our expert dementia advisors can give you advice and support. You can find more information, including opening hours, here: https://www.alzheimers.org.uk/dementia-connect-support-line

We hope this helps for now, Debbie. Please know that we are here for you if you need support. 

Alzheimer's Society blog team

My mom is 92. Has seizures and dementia. Won't admit to the dementia. She has huge mood swings and is very difficult to deal with. She goes from being weak and sick to practically running around the house doing things. She is suspicious and very unpleasant to be around when she feels good. But is kind and sweet when she feels bad. Is this normal for dementia patients? It makes it very hard to take care of her properly.

Hi Dana, I'm very sorry to hear about your mom. It sounds like a very difficult situation.

As a person’s dementia progresses, they may begin to behave differently than before. You can read more information about this here: https://www.alzheimers.org.uk/about-dementia/symptoms-and-diagnosis/symptoms/behaviour-changes 

We'd also recommend calling our support line on 0333 150 3456 to talk about this with one of our trained dementia advisers. They will listen to you and provide advice and support. You can find more details about the support line (including opening hours and other methods of contact) here: https://www.alzheimers.org.uk/dementia-connect-support-line

You may also find it helpful to join our online community, Talking Point. Here, carers and other people affected by dementia share their experiences and offer advice to others going through similar situations. You can browse topics within the community or sign up to join the conversation: https://forum.alzheimers.org.uk It’s open day or night and free to use.

We hope this helps for now.

I live in the US and I'm a nurse. I just want to share my story. Until this time my husband was a perfectly healthy 83 yr. old. Nov 2020 my he and I were sitting on the sofa talking. All of a sudden he was speaking only jibberish. My 1st thought was a stroke. I told him to put his right arm out and demonstrated what I meant. He put his left arm straight up. After a few more questions, I told him we were going to the hospital. He could walk. He walked downstairs and I told him to put his shoes on. He took one sock off and put his shoes on the wrong feet. By now he only gave me emphatic 'yes' answers to every question. I decided we needed an ambulance. I called. The EMTs thought he was having a stroke. In the hospital they first did a CT scan. It showed no stroke but he began with an obvious seizure. It was confined to his right face and arm. They did an MRI which showed severe cerebral atrophy. He was started on Keppra, a seizure med. He did fine except he still had the expressive aphasia that started at home the first morning. He could make his needs known but often got words mixed up. We gradually saw signs of memory loss and confusion. In April of 2021 he had another seizure at home. We went back to the hospital and his med was changed to Depakote. That did well. In Nov. 2021, he woke up and said he had a really bad night. He was just really "off". I slept by his side and wasn't aware of anything different but I told his neurologist and she increased his Depakote. He continued to decline with more confusion. He started having frequent bowel incontinence and sleeping much more. He was still walking but I was afraid of falls. Aug. 23 of this year, he was still in bed and I checked on him. He was having a seizure in his right arm and face again I called the ambulance. I expected a med change and we'd go home in a few days. It didn't happen this time. He didn't really wake up this time. The neurologist said there wasn't anything they could do anymore and signed off his case. He had no more seizures but continued to decline. He was in the hospital 12 days and passed away Sept 4 while I was with him. He was on comfort measures only and was just getting ativan regularly to keep him comfortable and prevent seizures. He was very comfortable but my heart is broken.
My Dad is in his 12th year of Alzheimers & vascular dementia. He started having seizures this year one lasted 7 minutes. Hes had 5 now and on medication. The home hes in fears hoisting him into a chair during the day incase he has a seizure in the arm chair. Hes very low In himself doesn’t communicate or move but i can see in his eyes how down he is. What can i do ?

Hi Fiona,

We're very sorry to hear about your Dad’s situation. It sounds like you are going through a difficult time.

We'd recommend calling our support line on 0333 150 3456 to speak with one of our trained dementia advisers. They will listen to you and provide specific information, advice and support that's relevant to your situation. You can find more details about the support line (including opening hours and other methods of contact) here: https://www.alzheimers.org.uk/dementia-connect-support-line

We hope this helps for now.

Alzheimer's Society blog team

My husband has mixed dementia. A year ago he had a seizure and was then hyper for about a week. Now he is in hospital with another seizure and they have said he has HYPO activity where’s he’s hardly been awake for 9 days now. He’s had dementia for 6 years. And up until this seizure was walking about and chatting the normal rubbish. Does anybody know about this hypo activity?
My wife has had dementia for a number of years and is totally dependent on me. As I type this she is sleeping heavily after a fit. She was sat on the bed and I was giving her a cup of coffee when she suddenly let out a strange yell went stiff and would have gone to the floor but for me catching her and putting her into the recovery position . She immediately went into a deep heavy breathing sleep. She is red faced. This is scary but I will just let her sleep as it happened in the same circumstances a few months ago….an ambulance was called and a day spent at A&E and nothing untoward found. Although scan impractical because of her condition. As this is the second I will see what GPsays about medication. So the purpose of this comment is that the first such attack for one you care for and about is frightening because it is alarming….but if it happens again one is better prepared ….and it is less so. Thank you to all others who have added their input which has certainly helped me to know that we are not alone in what we are experiencing
74 year old friend has begun to experience and absence issue—she stops and stares for a brief time. She can hear and is aware of everything around her, but is unable to respond in any way. Afterwards she feels very warm. Many days she is tired. I can’t find anything that describes her symptoms, starting as an adult. Does this sound familiar to anyone?

Hi Susan, we are sorry to hear about your friend’s situation.

We'd really recommend that she speaks to her GP about these concerns, as they are best placed to provide information in this situation.

If you need further support, please speak with one of our dementia advisers through our support line. They will be able to listen to you and provide you with advice and support.

Call our Dementia Connect support line on 0333 150 3456. More details about the support line (including opening hours) are available here: https://www.alzheimers.org.uk/dementia-connect-support-line.

We hope this helps.

I am 77 with MS & now seizure/dementia. I have seizures that it's like im asleep but know everything that is going on around me. & sleep a lot after. I'm now oñ 1000 namenda twice a day, don't have às many maybe 1-2 a month. Also maybe take à memory test in Drs office.

Hi there,

We're very sorry to hear this, it sounds like you're going through a difficult time. 

We'd recommend calling our support line on 0333 150 3456 to speak with one of our trained dementia advisers. They will listen to you and provide specific information, advice and support that's relevant to your situation. You can find more details about the support line (including opening hours and other methods of contact) here: https://www.alzheimers.org.uk/dementia-connect-support-line

We hope this helps for now.

Alzheimer's Society blog team

Yes this is similar to what happened to my Dad. He was subsequently diagnosed with a form of Epilepsy. His episodes/seizures were sudden - he might be speaking to you or even being active in the garden and then be completely vacant and completely static for a 10-15 seconds. He would come round and have short to medium term memory loss. He would still have long term memories and can recall who I am for example. Over the next hour or so he would start remembering a bit more about the previous hour. We now know this was a form of seizure in a specific part of the brain. He is on medication and doesn't have these seizures anymore luckily.
What medication is your Dad on?
My husband has alzeimers . Diagnosis confirmed 30 months ago. For me my concern probably 5 years ago, Recently on random occassion uncontrolled boby convulsions that increase in intensity. Mostly in the lower body but arms seem to be affected to a lesser degree. No warning, takes 30 or so steps and extreme shaking and wobbling of legs and must be propped up or sat down with help or he will collapse. Just to night I had the thought, could be related to alzheimers?
My MILl has been diagnosed with Alzheimer’s, for past 6-7 years..her current stage is where she cannot speak, moves very slowly,coughs while eating as she is having difficulty in swallowing and past 2-3 days also noticing incontinence in her bowels…she has had episodes of seizures in 2016 and later again in 2018 around..after reading your work above looks like this was an early sign of Alzheimer’s..