Dementia and Seizures: What is the link?

One of the lesser known symptoms of dementia is seizures. Although seizures have been linked to dementia for a long time, details of the relationship between dementia and seizures are still vague.

If you have dementia, you are likely to experience a range of different symptoms. Where some symptoms, such as memory loss, confusion and changes in behaviour, have become synonymous with the condition, there are other symptoms of dementia that are much less well known.

At a glance

• People living with dementia are more likely to experience seizures. People with dementia can experience seizures around six times more often than those without the condition. This is thought to be linked to changes and damage to brain cells caused by dementia.
• Seizures can occur at any stage of dementia. While seizures were once believed to be associated mainly with later-stage dementia, they can also occur in the early stages and, in some cases, even before memory problems become apparent.
• Some dementia-related seizures can be difficult to recognise. Focal onset or “silent” seizures may cause symptoms such as unresponsiveness, staring into space, or repetitive movements like chewing, lip smacking, or hand movements. These can be easily mistaken for dementia symptoms, making them harder to identify.

Are seizures common in dementia?

It is estimated that people living with dementia can experience seizures around 6 times more often than people without the condition.

What is the link between dementia and seizures?

Both dementia and seizures occur as a result of changes or damage to cells within your brain and affect how your brain functions. It is the damage to the brain caused by dementia that is thought to make you more susceptible to seizures. 

However, because different types of dementia are caused by damage to different parts of the brain, the relationship between the disease and seizures does not follow one obvious path. People may experience different types of seizures based on the nature of their dementia. 

For example, frontotemporal dementia is caused by a build-up of abnormal proteins in the brain. These proteins are thought to make the brain cells more ‘excitable’, causing them to behave uncontrollably, resulting in a seizure. 

There is also greater knowledge about at what stage of dementia a person’s risk of seizures increases.

Seizures were thought to be a symptom associated with the later stages of dementia, due to progressive changes in the brain. However, seizures are now also considered to be an early symptom- occurring even before any signs arise that your memory is compromised. This means that a person may experience seizures at any point in their dementia journey. 

People with dementia are more likely to experience seizures than a person without the disease. If you, or a loved one, have had a seizure or are concerned about the likelihood of having a seizure, it is good to understand the different types of seizures and treatments available. 

What does a dementia seizure look like?

The different types of seizures are categorised by where they start in the brain.

They can be either:

• Generalised onset. This type of seizure affects both sides of the brain.
• Focal onset. This seizure starts in and affects one part of the brain.
• Unknown onset. This term is used when medical professionals cannot identify where in the brain the seizure started. 

What are the symptoms of seizures?

Seizures within each category can manifest in different ways. A person can experience different levels of consciousness. 

Generalised onset seizures

There are a number of ways generalised onset seizures can present themselves.

The most common is the ‘clonic seizure’. This causes a person’s body to stiffen and convulse and they will usually be unresponsive during the period of the seizure. Clonic seizures are normally easy to visually identify as they are what most of us will expect a seizure to look like. 

Focal onset seizures

Often referred to as ‘silent seizures’, focal onset seizures are much more difficult to identify, especially if a person hasn’t previously experienced them. 

Symptoms can include:

• Unresponsiveness or appearing absent. 
• Repetitive movements such as chewing, lip smacking, swallowing or movement of the hands and arms.

People living with dementia are at increased risk of this type of seizure and because it is easy to miss. It can take a while before a ‘silent seizure’ is identified as happening. 

The elusive nature of focal onset seizures is exacerbated by the fact that silent seizures and dementia share similar symptoms. This means you, your loved ones and even your GP may overlook silent seizures as other common symptoms of dementia. 

It’s important to note that experiencing a seizure does not automatically mean that you are epileptic.

If you, or your loved one, have experienced a seizure, you should visit your GP who will then be able to refer you to a specialist. An epilepsy diagnosis will usually only be given following a number of seizures. 

What treatment is available for seizures?

There are a variety of different treatments available to help stop or reduce seizures.

This includes:

• Medication
• Surgery
• Alternative treatments

In most cases, treatment of any kind won’t be recommended unless you have experienced more than one seizure.

This is especially relevant if you have dementia. Factors such as medication already being taken and potential side effects may prevent a specialist from recommending treatment for seizures.

Some anti-seizure medication has been shown to slow down the progression of dementia.

Because seizures can cause further damage to the brain, each seizure has the potential to increase cognitive decline. Taking medication to prevent or stop seizures completely will help to lessen the impact they can have on the brain. 

Dementia varies greatly from person to person. There isn’t one single solution or explanation for the varied symptoms and changes that you can experience.

If you have dementia and have experienced a seizure, it is important that you spend time consulting with health professionals to determine the next best steps to keep you safe and maintain your quality of life. 

You can read more about epilepsy and the treatments available in our article here.

FAQs