Dementia and seizures are common conditions with a bi-directional relationship. Living with dementia may put you at an increased risk of seizures, and living with seizures may increase your risk of dementia.

Dementia is an umbrella term for conditions of memory loss and cognitive decline beyond what’s natural during the aging process. Alzheimer’s disease is the most common type of dementia, making up as many as 80% of diagnoses.

Because dementia is associated with memory function, many people don’t realize there’s also a link between dementia and seizures.

Experiencing seizures with dementia, however, can be an important clue into the progression of neurodegeneration and dementia outcomes.

The exact link between dementia and seizures isn’t currently well understood. Researchers hypothesize that neuron loss in the brain from dementia causes abnormal electrical activity, which may lead to seizures.

Because dementia is progressive and most damage to neurons is permanent, there’s an ongoing chance of experiencing disrupted electrical signaling. For many people living with dementia, seizures are recurrent and meet the diagnostic criteria for epilepsy.

Dementia and recurrent seizures appear to have a bi-directional relationship.

According to a 2020 study, living with dementia brings a twofold risk of developing epilepsy, and living with epilepsy brings a twofold risk of developing dementia.

In a research review from 2022, researchers discovered that seizures may cause amyloid plaque deposits to form. These could be the same amyloid plaques noted in Alzheimer’s disease. This means developing epilepsy first can predispose you to develop Alzheimer’s, just as developing Alzheimer’s first might lead to recurrent seizures.

According to a 2021 study of more than 79,000 people, generalized and focal seizures are the most common seizures among people living with dementia.

Generalized seizures are those that can create body-wide jerking movements, falls, or a total loss of consciousness. They occur when both sides of your brain have a sudden increase in electrical activity.

Types of generalized seizures include:

Focal seizures originate from one part of the brain. They can alter your consciousness, inducing a dream-like awareness, and can involve emotional shifts, sensory experiences, and unusual motor functions.

Seizure symptoms in people with dementia

There are many types of seizures, and your symptoms will depend on the part or parts of your brain being affected.

Symptoms of seizures in people with dementia can include:

  • subtle motor twitches
  • hallucinations
  • changes to your conscious state
  • automatisms (repetitive behaviors)
  • auras, or unusual sensations preceding a seizure
  • sudden unexplained bruises or localized aches and pains
  • jerking movements
  • body stiffening
  • loss of muscle tone
  • staring off “into space”

Additionally, some people might have a headache or a sudden emotional shift after a seizure.

A 2020 study found that people diagnosed with Alzheimer’s disease who had a history of seizures had a seizure recurrence risk of over 70% within 7.5 months.

In fact, people living with Alzheimer’s disease, the most common type of dementia, experience recurrent seizures up to 6.5 times more often than people not living with dementia.

The exact causes of seizures in dementia aren’t known, but erratic electrical signaling caused by neuron death may play a role.

Both seizures and dementia can cause irregular electrical signals in the brain, a feature that might explain why they’re independent risk factors for one another.

Risk factors for seizures in people with dementia

The exact risk factors for seizures in dementia are unclear, though the amount of time you’ve lived with dementia appears to increase your seizure risk.

Factors that may increase someone’s chances of epilepsy include:

  • low birth weight or premature birth
  • congenital brain structure differences
  • brain bleeding
  • seizures within a month of birth
  • traumatic brain injury
  • lack of oxygen to the brain
  • brain tumors
  • atypical blood vessels in the brain
  • stroke
  • brain infections
  • cerebral palsy
  • trauma during birth
  • family history of seizures
  • certain mental health conditions
  • a history of fever-related seizures
  • alcohol or drug misuse

Seizures in dementia are typically associated with advanced stages of the condition. When there are more neurons damaged in the brain, the more erratic the electrical signaling in the brain can become.

This is why the amount of time you have lived with dementia can affect your chances of having a seizure.

A 2020 study of more than 20,000 people found that seizure risk rose from 1.5% at the 4.8-year mark in dementia to 5.4% at the 11-year mark.

Can seizures make dementia worse?

Seizures are associated with worse dementia outcomes.

A history of seizures has been linked to:

  • a younger age of onset for dementia cognitive decline
  • more severe memory challenges overall
  • a higher level of everyday impairment

According to a 2016 research review, antiepileptic medications like gabapentin and lamotrigine are the treatments of choice for epilepsy in people with dementia.

Some anticonvulsants may make other symptoms of dementia worse, and anticonvulsants used to treat seizures or other symptoms of dementia could be associated with worsening brain atrophy and cognitive decline.

Currently, epilepsy and dementia together are treated with antiepileptic medications that focus on symptom management.

Some research is beginning to examine whether any other treatments could be beneficial for treating this combination of conditions, but there haven’t been any benefits established yet.

These treatments include:

Dementia and seizures have a bi-directional relationship. Living with one may increase your chances of developing the other.

But not everyone living with dementia will develop seizures — just as not everyone who has seizures will develop dementia. However, the longer you live with dementia, the higher your chances of experiencing a seizure become.

Both conditions involve irregular electrical impulses in your brain, which may be why they’re so closely related.