One In Four With Epilepsy Had Functional Seizures

What was studied

This study looked at people age 16 and older with idiopathic generalized epilepsy (IGE) who were admitted to one hospital's epilepsy monitoring unit for inpatient video-EEG between 2008 and 2024. The researchers wanted to estimate how often functional/dissociative seizures (FDSs) occurred along with epilepsy, describe what those FDSs looked like, and identify clinical features potentially associated with having video-EEG-diagnosed FDSs.

It was a retrospective, single-center study. That means the researchers reviewed past records rather than assigning treatments or following people forward in time. They studied 123 patients with IGE and compared those who had video-EEG-documented FDSs with those who did not.

What they found

Out of 123 patients with IGE, 29 had co-occurring FDSs recorded on video-EEG, which was about 1 in 4 patients in this monitored group. Nearly all of those 29 patients were female. The most common FDS subtype was subjective nonmotor events. Many patients had multiple FDS episodes, but most presented with a single FDS subtype.

Generalized interictal discharges were seen on EEG in almost all of the patients with FDSs, often on the first day of admission. Epileptic seizures were also captured during the same hospital stay in about 45% of the patients with FDSs. Among the clinical variables analyzed, female sex was associated with co-occurring FDSs, but this association did not remain significant after Bonferroni correction.

Limits of the evidence

This study cannot show that IGE leads to FDSs or explain why some patients had both. It was done at a single center and only included patients admitted for inpatient video-EEG, so the results may not apply to all people with IGE. The group with FDSs was small, with 29 patients, which limits confidence in subgroup findings.

Because this was a retrospective chart review, the study depended on what was already recorded in the medical record. The abstract does not provide detailed information about other possible factors, such as mental health history, medications, or how patients were selected for monitoring. The reported prevalence reflects this monitored inpatient IGE group, not necessarily the broader IGE population.

For families and caregivers

For families, this study suggests that some people with generalized epilepsy who are admitted for video-EEG monitoring may also have functional/dissociative seizures, and both event types can occur in the same person. That matters because these events may look different. Video-EEG can help doctors determine whether a spell is epileptic, functional/dissociative, or both.

The findings do not mean that about one quarter of all people with IGE have FDSs. This number came from a selected group of patients who underwent inpatient monitoring. The abstract concludes that video-EEG referral should be considered in patients with suspected drug-resistant IGE with active seizures or when there is clinical suspicion of FDSs.

What to watch next

Larger studies from more than one center could help clarify how common co-occurring FDSs are in IGE and which clinical features are associated with them.

Terms in this summary

idiopathic generalized epilepsy (IGE)

A group of epilepsies with generalized seizure types and generalized EEG findings, without a structural cause identified in the abstract.

functional/dissociative seizures (FDSs)

Episodes that resemble seizures but are classified separately from epileptic seizures and were identified here using video-EEG.

video-EEG

A hospital test that records brain waves and video at the same time to help identify what kind of event a person is having.

semiology

The observable or reported features of a seizure or seizure-like event, such as movements, behavior, or symptoms.

interictal discharges

Abnormal EEG patterns seen between seizures.

subjective nonmotor

An event subtype mainly involving internal symptoms or experiences rather than visible movement.

retrospective study

A study that looks back at existing records rather than following people forward in time.