Absence seizures in elderly adults are far more common than most people realize, but they look almost nothing like the brief “staring spells” familiar from childhood epilepsy textbooks. In older adults, these episodes typically present as prolonged confusion, odd behavior, or a sudden drop in mental sharpness that can last minutes to hours, and they are frequently mistaken for dementia, delirium, or even a stroke. Because the seizures lack the dramatic convulsions most people associate with epilepsy, they often go unrecognized for weeks or months, delaying treatment that could resolve the problem entirely.
What Absence Seizures Actually Look Like in Older Adults
In children, a classic absence seizure is a brief blank stare lasting a few seconds, after which the child picks up exactly where they left off. The elderly version is a different animal. Rather than a momentary lapse, older adults tend to experience what neurologists call absence status epilepticus: a prolonged episode of impaired awareness that can stretch from thirty minutes to several hours, sometimes even days. During these episodes, a person may appear confused, respond slowly or not at all, behave strangely, or seem “out of it” in a way that family members and even emergency physicians often attribute to something else entirely.
The clinical picture can range from mild clouding of awareness to near-complete unresponsiveness. Some patients show subtle motor signs, like slight twitching of the eyelids, repetitive lip-smacking, or small jerking movements of the fingers, but these are easy to overlook, especially in someone already frail or cognitively impaired. Others show no visible motor activity at all, just a sustained change in behavior or alertness.1Revue Neurologique. Nonconvulsive status epilepticus in the elderly This is what makes the condition so slippery to diagnose at the bedside.
Why These Seizures Get Mistaken for Dementia and Delirium
The overlap between absence seizures and common geriatric conditions is enormous. A 76-year-old with dementia who suddenly becomes more confused, stops speaking coherently, or starts behaving erratically will almost always be evaluated for a urinary tract infection, a medication reaction, or worsening of their underlying cognitive disease. Epileptic seizure activity is rarely the first thing anyone considers. One case report described exactly this scenario: a woman with known dementia experienced an abrupt change in cognition and behavior that turned out to be nonconvulsive status epilepticus, not disease progression.2PubMed Central. Nonconvulsive seizures and dementia: a case report
The confusion runs in both directions. Temporal lobe epilepsy in an older adult can produce a slow, insidious decline in memory and thinking ability that closely mimics Alzheimer’s disease. A patient evaluated for progressive cognitive decline may actually be experiencing recurrent subclinical seizures that are steadily eroding brain function.3PubMed Central. Dementia with non-convulsive seizures: a case report Because seizures are treatable and many dementias are not, missing this distinction has serious consequences.
Delirium is another frequent mimic. A prospective study using continuous EEG monitoring in older hospitalized adults with delirium found that about 12% of them were actually in nonconvulsive status epilepticus, and an additional 30% showed abnormal electrical discharges between seizures. The seizure activity rates were similar whether the delirium had an obvious medical cause or appeared to have no clear explanation.4PubMed Central. Role of Epileptic Activity in Older Adults With Delirium, a Prospective Continuous EEG Study In other words, a meaningful fraction of elderly patients diagnosed with delirium may be seizing without anyone knowing it.
Absence status epilepticus has also been confused with transient global amnesia, the sudden-onset memory loss that sometimes strikes middle-aged and older adults. One report described a 68-year-old woman whose recurrent episodes of confusion, abnormal behavior, and amnesia lasting several hours were initially thought to be transient global amnesia before EEG revealed continuous generalized spike-and-wave discharges consistent with absence status.5Epileptic Disorders. Juvenile absence epilepsy relapsing as recurrent absence status, mimicking transient global amnesia, in an elderly patient These episodes had been happening for years before the correct diagnosis was made.
De Novo Onset Versus Reactivation of Old Epilepsy
One of the more surprising aspects of absence seizures in older adults is that they can appear for the first time in someone who has never had epilepsy. Neurologists call this “de novo” late-onset absence status epilepticus. In many of these cases, the seizures are triggered by something identifiable: withdrawal from benzodiazepines (a class of sedatives commonly prescribed to older adults), alcohol intoxication, or the introduction of certain psychotropic medications.6PubMed. Idiopathic late-onset absence status epilepticus: a case report with an electroclinical 14 years follow-up Remove the trigger, treat the seizure, and the patient may never have another episode.
But not all late-onset cases are truly “new.” Some represent the reactivation of a childhood or adolescent epilepsy that had been in remission for decades, sometimes so long that neither the patient nor their family remembers the original diagnosis. A systematic review of patients with electroclinical features suggestive of late-onset idiopathic generalized epilepsy found a median age at seizure onset of 71 years, and a family history of epilepsy was reported in two-thirds of them.7PubMed. De novo late-onset absence status epilepticus or late-onset idiopathic generalized epilepsy? A case report and systematic review of the literature That high rate of family history hints that at least some of these patients have a genetic predisposition that simply waited decades to resurface.
Clinicians have delineated at least four distinct patterns of nonconvulsive status epilepticus in the elderly: absence status in a patient with pre-existing generalized epilepsy, de novo absence status triggered by benzodiazepine withdrawal, complex partial status epilepticus from a focal brain lesion, and subtle generalized status epilepticus in a comatose patient as the tail end of a convulsive seizure.8Age and Ageing. Non-convulsive status epilepticus in elderly individuals: report of four representative cases The treatment and outlook differ considerably depending on which pattern is at play, which is why getting the right diagnosis matters so much.
The Role of Alzheimer’s Disease and Other Neurodegenerative Conditions
Alzheimer’s disease deserves its own mention because the connection to seizure activity is stronger than most people assume. Patients with mild to moderate Alzheimer’s have been reported to have seizure rates in the range of 8% to 18%, and the actual rate of subclinical epileptic brain activity is likely much higher. One study using overnight video-EEG monitoring found evidence of epileptiform activity in up to 42% of Alzheimer’s patients.9PubMed Central. Dementia with non-convulsive seizures: a case report These are not the dramatic convulsions that land someone in the emergency room. They are quiet, invisible electrical storms that may be silently worsening cognitive function.
This creates a vicious feedback loop. The neurodegeneration from Alzheimer’s lowers the brain’s threshold for seizure activity, and the seizure activity in turn accelerates cognitive decline. For a caregiver watching a loved one deteriorate, it can be hard to tell whether the person is simply getting worse from their underlying disease or whether treatable seizures are contributing to the decline. When sudden, step-wise drops in function occur rather than the usual slow slide, seizure activity should be high on the list of suspects.
Metabolic Triggers That Can Provoke Seizures in Older Adults
Not every seizure in an elderly person points to epilepsy. Acute electrolyte disturbances can trigger seizures on their own, and older adults are particularly vulnerable to these imbalances because of age-related changes in kidney function, chronic medication use, and reduced fluid intake. Sodium disorders, especially low sodium (hyponatremia), along with low calcium and low magnesium, are the most commonly implicated electrolyte problems. Seizures caused by these disturbances are classified as acute symptomatic seizures rather than epilepsy, and they resolve when the underlying metabolic problem is corrected.10PubMed Central. Acute Symptomatic Seizures Caused by Electrolyte Disturbances
This distinction matters for treatment. A person who seizes because their sodium dropped too low does not need long-term anti-seizure medication. They need their sodium level fixed and a review of whatever caused it to drop, often a diuretic, an antidepressant, or simply inadequate fluid intake. Jumping straight to epilepsy drugs in this situation introduces side-effect risk without addressing the actual cause. Basic blood work in the emergency department can often sort this out quickly, but the step gets skipped surprisingly often when the presentation looks like “confusion in an elderly patient.”
Getting the Diagnosis Right
The single most important diagnostic tool for absence seizures in older adults is the electroencephalogram (EEG), and it often needs to be done urgently. A standard EEG records the brain’s electrical activity through electrodes on the scalp and can detect the generalized spike-and-wave patterns that define absence seizures. In typical absence status epilepticus, the EEG shows frequent, recurrent bursts of synchronous spike-and-wave or polyspike-and-wave activity, interrupted by brief stretches of normal background rhythm.11Seizure. Typical absence status epilepticus as late presentation of idiopathic generalised epilepsy in an elderly patient That normal background is actually a helpful clue: it distinguishes this condition from many other forms of status epilepticus where the baseline brain activity is itself abnormal.
The challenge is that an EEG is not always immediately available, especially outside major academic medical centers. A short routine EEG may also miss the diagnosis if the seizure activity is intermittent. Continuous EEG monitoring, where the electrodes stay on for hours or even days, dramatically improves detection. In one study of elderly patients with suspected epilepsy who underwent inpatient diagnostic video-EEG monitoring, the procedure led to definitive diagnoses in many cases, including the identification of treatable medical conditions that had been misattributed to epilepsy.12PubMed. Value of inpatient diagnostic CCTV-EEG monitoring in the elderly Over half of those patients turned out to have conditions that did not respond to anti-seizure drugs at all, reinforcing how often the diagnosis is wrong without EEG confirmation.
Several clinical red flags should prompt urgent EEG testing in an older adult with acute confusion. A systematic review found that female sex, a known history of epilepsy or a recently witnessed seizure with motor features, and abnormal eye movements all correlated with a diagnosis of nonconvulsive status epilepticus in elderly patients presenting with acute confusion.13PubMed. Prevalence and clinical correlates of non-convulsive status epilepticus in elderly patients with acute confusional state: A systematic literature review Any of these features in a confused older person should lower the threshold for ordering an EEG rather than assuming the confusion is “just delirium.”
Treatment and Prognosis
The good news is that when absence seizures in the elderly are correctly identified, they often respond well to treatment. For acute episodes of absence status epilepticus, intravenous benzodiazepines like lorazepam can terminate the seizure activity quickly, sometimes within minutes. The more important question is what to do afterward to prevent recurrence.
For patients with de novo absence status triggered by an identifiable cause like benzodiazepine withdrawal or a new medication, the treatment may be as simple as removing the trigger. For those with an underlying generalized epilepsy, whether newly recognized or reactivated after decades of remission, longer-term medication is usually necessary. The systematic review of late-onset idiopathic generalized epilepsy found that all six patients for whom treatment outcomes were reported achieved seizure freedom on a single anti-seizure medication, most commonly valproic acid and less often lamotrigine, over follow-up periods ranging from three months to two years.14PubMed. De novo late-onset absence status epilepticus or late-onset idiopathic generalized epilepsy? A case report and systematic review of the literature
Medication choice in elderly patients requires extra care. Valproic acid, while effective for generalized seizures, carries risks in older adults including tremor, weight gain, low platelet counts, and potential worsening of cognitive function, all of which can be particularly problematic in someone already dealing with age-related health issues. Lamotrigine is generally better tolerated but requires a slow dose escalation to avoid a potentially serious skin reaction. The key principle is to start low, increase slowly, and monitor carefully. Most elderly patients need lower doses than younger adults because their bodies process drugs more slowly.
The Burden on Patients and Caregivers
Living with seizures in old age carries burdens that go well beyond the seizures themselves. A study evaluating new-onset seizures in the elderly found that patients scored significantly lower on all quality-of-life measures at six months of follow-up, and over half of their caregivers reported mild to moderate burden from providing care.15International Journal of Epilepsy. New Onset Seizure in the Elderly: Classification, Etiology, and Impact on Quality of Life and Caregiver Burden
When older adults with epilepsy were asked directly about their concerns, the results painted a picture of practical frustrations as much as medical ones. About two-thirds listed driving restrictions and medication side effects as their top worries, followed by concerns about personal safety, medication costs, employment, social embarrassment, and memory loss.16Epilepsy & Behavior. What are the concerns of older adults living with epilepsy? For someone in their sixties or seventies who was previously independent, losing the ability to drive can be functionally devastating, eliminating access to groceries, medical appointments, and social connections in one stroke. Medication side effects layer on top of whatever other drugs the person is already taking, creating a tangle of interactions and trade-offs that complicates treatment decisions.
The social embarrassment dimension deserves attention too. An older adult who has a confusional episode in public, behaves oddly at a family gathering, or cannot follow a conversation may withdraw from activities out of fear of it happening again. Family members who do not understand the diagnosis may quietly attribute these episodes to “getting old” or early dementia, reinforcing the patient’s isolation. Accurate diagnosis and effective treatment can reverse much of this, but only if the seizures are recognized in the first place.
When to Push for an EEG
If you are caring for an older adult who has experienced sudden, unexplained changes in mental status, particularly episodes of confusion that come and go, or sudden worsening of cognitive function in someone with known dementia, it is reasonable to ask the treating physician whether an EEG has been considered. The episodes most suggestive of nonconvulsive seizures tend to have a relatively clear onset rather than developing gradually over days, and they often resolve on their own after minutes to hours, leaving the person tired but more or less back to baseline. Subtle motor signs like eye twitching, lip movements, or repetitive hand movements during the episode add further suspicion.
Emergency departments and general hospital wards are not always equipped for continuous EEG monitoring, and the default assumption when an elderly patient presents with confusion is often infection, medication toxicity, or stroke. Advocating for an EEG in the right clinical context can make the difference between a correct diagnosis and months of unnecessary testing, medication changes, or a premature label of dementia. The evidence consistently shows that nonconvulsive seizures in this age group are underdiagnosed, and when they are caught and treated, many patients improve dramatically.17PubMed Central. Nonconvulsive seizures and dementia: a case report