Focal Seizures: The Most Common Seizure Type in the Elderly
For many, the image of a seizure involves violent, full-body convulsions. However, studies show that in the elderly population, this is often not the case. The most prevalent type of seizure is the focal seizure, which begins in one area of the brain and presents with more subtle, varied symptoms. These focal seizures are often more challenging to diagnose because their manifestations can be mistaken for other age-related conditions, such as dementia or delirium.
Subtypes of Focal Seizures
Focal seizures can be categorized by their effect on awareness during the event. Understanding these differences is critical for proper identification and treatment.
- Focal Seizures with Impaired Awareness: This is the most common subtype in older adults. During this type of seizure, the person loses or has a change in consciousness. They may appear to be awake but are unresponsive to their surroundings. Symptoms can include blank staring, repetitive behaviors (automatisms) like lip-smacking, hand rubbing, or chewing, and mumbling. The person typically does not remember the seizure afterward.
- Focal Seizures without Impaired Awareness: In this type, the person remains conscious and aware. Symptoms are often sensory or emotional. They might experience sudden sensations, such as a strange smell, taste, or tingling, or feel unexplained fear or déjà vu. Motor symptoms, such as the jerking of a single limb, can also occur without loss of consciousness.
Why Seizures are Different in Older Adults
The way seizures manifest in seniors differs from younger populations for several key reasons, including distinct underlying causes and changes in brain function.
- Underlying Causes: In contrast to younger adults, where epilepsy is often idiopathic (of unknown cause), seizures in seniors are frequently symptomatic, meaning they are caused by an underlying medical condition. Cerebrovascular disease, such as stroke, is the most common culprit, responsible for up to 50% of identifiable causes. Other frequent causes include neurodegenerative diseases like Alzheimer's disease, brain tumors, and metabolic disturbances.
- Location of Seizure Activity: The epileptic focus in older adults is often in the frontal and parietal lobes, rather than the temporal lobe, which is more common in younger people. This shift in location can lead to a different set of symptoms, such as dizziness or posturing, and less commonly the classic auras associated with temporal lobe epilepsy.
- Longer Postictal Confusion: The period following a seizure (the postictal phase) is often significantly longer in the elderly, lasting for hours or even days. This prolonged confusion can be mistaken for other conditions, further complicating diagnosis.
Diagnosis and Management of Seizures in the Elderly
Given the atypical presentation, diagnosing seizures in older adults requires a careful evaluation. Doctors often use a combination of methods:
- Electroencephalogram (EEG): This test records the electrical activity of the brain and can help identify abnormal brain activity characteristic of seizures.
- Neuroimaging (MRI or CT): These scans are crucial for identifying underlying structural causes, such as a brain tumor, stroke, or other brain lesions.
- Blood Tests: Metabolic conditions, such as low sodium (hyponatremia), low blood sugar (hypoglycemia), or kidney failure, can trigger seizures and are identified through blood work.
Treatment Options for Geriatric Seizures
Treatment often involves anti-seizure medications, but careful consideration is needed for older patients due to co-morbidities and potential drug interactions.
- Anti-Seizure Medications (ASMs): Doctors often start with low doses of a single ASM and monitor for side effects, as the elderly can be more sensitive to medication. Common medications include levetiracetam (Keppra), lamotrigine (Lamictal), and lacosamide (Vimpat).
- Addressing Underlying Causes: If the seizure is symptomatic, managing the underlying condition is the most important step. For example, controlling blood sugar levels in diabetics or treating infections can resolve the seizures.
- Lifestyle Modifications: Strategies like getting adequate sleep, avoiding alcohol, and managing stress can help reduce seizure triggers.
Seizure Characteristics: Elderly vs. Younger Adults
| Feature | Elderly Patients (60+) | Younger Adults (18-45) |
|---|---|---|
| Most Common Seizure Type | Focal impaired awareness seizures, sometimes progressing to tonic-clonic | All types, but often idiopathic generalized seizures |
| Symptom Presentation | Shorter duration, subtle features like blank stares, confusion, or repetitive motions | More overt clinical features, such as classic auras or automatisms |
| Common Underlying Causes | Cerebrovascular disease (stroke), Alzheimer's/dementia, brain tumors | Often idiopathic (unknown) or genetic factors |
| Postictal (Recovery) Period | Often prolonged, lasting for hours or days, contributing to confusion | Generally shorter, lasting minutes to a few hours |
| Diagnosis Challenges | Symptoms can mimic dementia, delirium, or 'funny turns,' leading to misdiagnosis | Often clearer and more easily recognized symptoms |
| Treatment Challenges | Comorbidities and multiple medications increase risk of side effects and drug interactions | Fewer comorbidities; medication selection is often more straightforward |
Conclusion
The most common seizure experience by the elderly is the focal seizure, which frequently goes unrecognized due to its subtle symptoms that can be easily mistaken for other age-related issues. Atypical presentation, longer postictal confusion, and underlying cerebrovascular disease or dementia differentiate seizures in older adults from those in younger populations. Prompt diagnosis through EEG, imaging, and lab work is essential to identify the root cause and initiate appropriate management. With proper treatment and a focus on managing underlying conditions, many older adults can achieve good seizure control and maintain a high quality of life. It is critical for caregivers and healthcare providers to be aware of these unique aspects to ensure timely and effective intervention.
Understanding Epilepsy in Older Adults is a useful resource for more information and support.
