So far in this series, we’ve explored how epilepsy—especially when misdiagnosed—can contribute to cognitive decline and even dementia. But the relationship between these two conditions goes both ways. Dementia doesn’t just affect memory and reasoning—it can also increase the brain’s vulnerability to seizures. In this post, we’ll unpack how and why dementia can lead to epilepsy, and why these seizures are often overlooked in older adults. While it’s clear that epilepsy can increase dementia risk, the reverse is also true—dementia can make individuals more susceptible to developing epilepsy.  

Why Do Dementia Patients Develop Seizures? 

As dementia progresses, the brain undergoes a number of changes that can increase the risk of seizure activity. These changes don’t happen overnight; they build over time, gradually altering the brain’s chemistry and structure. Here are some of the key factors: 

Amyloid and Tau Protein Deposits 

In Alzheimer’s disease, abnormal buildup of amyloid plaques and tau tangles interferes with the brain’s ability to communicate effectively. These proteins not only contribute to cognitive decline but also disrupt the electrical signals that keep brain activity stable—making seizures more likely (Zhang et al., 2022). 

Inflammation and Oxidative Stress 

Chronic neuroinflammation is a hallmark of many forms of dementia. The brain’s immune response, while initially protective, can become harmful when prolonged. Inflammation and oxidative stress can damage neurons and make them hyperexcitable, increasing the likelihood of seizure activity (Zhang et al., 2024). 

Brain Atrophy and Structural Degeneration 

As dementia progresses, key brain regions—especially the hippocampus and temporal lobes—begin to shrink. This process, known as brain atrophy, can lead to abnormal electrical firing in areas involved in memory and awareness, which are also common seizure sites (Sen et al., 2018). 

The Hidden Nature of Dementia-Related Seizures 

One of the biggest challenges in diagnosing seizures in dementia patients is that the symptoms can be incredibly subtle. Dementia-related epilepsy is often underdiagnosed because seizures in older adults tend to be “silent” or appear as brief lapses in awareness rather than full-body convulsions (Vossel et al., 2017). This makes accurate diagnosis critical for proper treatment. 

Common signs include: 

• Sudden staring spells or brief lapses in awareness 

• Periods of confusion that come and go 

• Increased disorientation following a “spell” 

• Involuntary movements or twitching on one side of the face or body 

• Unexplained changes in behavior or alertness 

Because these symptoms can resemble the natural fluctuations in attention or cognition that occur with dementia, seizures are often underdiagnosed—meaning many patients miss out on treatments that could significantly improve their quality of life (Vossel et al., 2017). 

Why It Matters:  

Detecting and managing seizures in people with dementia is essential for improving quality of life. When seizures go undiagnosed, patients miss out on treatment options that could stabilize cognition and slow functional decline. While epilepsy in dementia is often subtle, neurologists can use tools like electroencephalography (EEG) to detect abnormal brain activity and guide treatment decisions. 

As research continues to reveal the hidden connections between dementia and epilepsy, early diagnosis and intervention become even more important. Identifying seizure activity may open the door to therapies that improve cognitive outcomes and enhance daily life for patients and caregivers alike. 

Coming Next: 
In our next article, we’ll explore what treatment looks like for patients living with both epilepsy and dementia, and how caregivers and clinicians can support them through tailored care approaches. 

For more resources or to learn more about epilepsy and dementia, contact the Epilepsy Foundation of Northeastern New York at (518) 456-7501 or visit our website.  

References 
Sen, A., et al. (2018). Cognition and dementia in older patients with epilepsy. Brain: A Journal of Neurology. 
Vossel, K. A., et al. (2017). Incidence and impact of subclinical epileptiform activity in Alzheimer’s disease. Annals of Neurology. 
Zhang, D., et al. (2022). The clinical correlation between Alzheimer’s disease and epilepsy. Frontiers in Neurology. 
Zhang, Y., et al. (2024). Oxidative stress and neuroinflammation in dementia: Implications for seizure susceptibility. Journal of Neurodegenerative Research.