Can dementia cause seizures?

What is the link between seizures and dementia?<

Patients with dementia experience a range of symptoms linked to cognitive impairment, such as memory issues and paranoid delusions. Seizures are a less common symptom of dementia. This symptom is also not as understood and reported on as other symptoms of cognitive decline, such as memory loss.

Seizures occur more frequently in patients with Alzheimer’s disease, dementia with Lewy bodies, frontotemporal dementia, and progressive supranuclear palsy than in other dementias. ^[3] However, the rate at which seizures occur in these various forms of dementias varies.

Alzheimer’s disease is the most common form of dementia. In individuals with Alzheimer’s disease, roughly 10-22% will experience at least one seizure. ^[2] Seizures will typically occur in later stages of the disease, with at least 6 years of time passing after diagnosis before an individual experiences their first seizure. [2 Seizures are more likely to affect Alzheimer’s patients who were diagnosed with the early-onset form of the disease ^[2].

Symptoms of a seizure

A seizure is a sudden, uncontrolled body movement that is prompted by irregular electrical activity in the brain. While seizures typically manifest physically as body convulsions, they can also present more subtly as behavioral changes, emotional changes, or changes in levels of consciousness.

The two prevalent forms of seizures seen in patients with Alzheimer’s disease are: ^[2]

• Generalized tonic-clonic seizures: Affected individuals experience full-body convulsions, often combined with sudden loss of consciousness and incontinence.
• Partial complex seizures: Affected individuals appear unaware of their surroundings, make random body movements such as lip smacking or fidgeting with their hands, and stare blankly.

Diagnosis of dementia-related seizures

Seizures are typically identified by an imaging study called an electroencephalogram (EEG). An EEG measures cerebral electrical activity. However, it can only definitively diagnose dementia related seizures if they occur while the imaging study is taking place.

Similarly, while genetic blood tests and MRI scans can provide supportive insights into diagnosing dementia-related seizures, they are not conclusive in their own right.

Due to these limitations, seizures related to dementia, specifically Alzheimer’s disease, relies on a seizure screening questionnaire. ^[4] The content of the questionnaire can vary, but generally its aim is to assess an individual’s family history, medical history, seizure history, and description of symptoms. ^[4]

A medical professional will typically use an algorithm to ascertain an individual's risk of seizures based on their answers. A positive questionnaire result, combined with irregular electrical activity identified on an EEG, can lead to an accurate diagnosis of dementia-related seizures. ^[4]

Treatment for dementia-related seizures

Anticonvulsant medication such as Depakote, Lamictal and Neurontin are typically prescribed to treat Alzheimer’s-related seizures. ^[2]

When to seek medical help

As seizures can be hard to identify in dementia patients, it is imperative you seek medical help as soon as you suspect they could be occurring.

Aside from more obvious symptoms, such as convulsions, other indications of dementia-related seizures include:

• Excessive twitching or blinking
• Infrequent involuntary urination
• Lip smacking
• Spells of irregular behavior