Which seizure elements do patients memorize? A comparison of history and seizure documentation

People with epilepsy (PWE) are frequently unable to recall the core manifestation of their disease, epileptic seizures. This means that seizure frequency is often underestimated by practitioners and that seizure classification based on reports of patients or their relatives is difficult because seizure semiology remains unclear. The purpose of this study, therefore, was to prospectively explore patients' memory regarding seizure elements and to assess the role of seizure types.

Ninety patients diagnosed with focal epilepsy undergoing diagnostic electroencephalography (EEG)-video monitoring were included. The ability to memorize individual seizure elements was assessed using a questionnaire. Patient knowledge was then compared to the findings of subsequent seizure documentation during EEG-video monitoring. Seizure elements were categorized in four groups: subjective, motor, autonomic, and postictal elements.

In all categories, the number of documented seizure elements during monitoring strongly exceeded the number of elements that were recalled. Only 45.6% of subjective elements, 5.4% of motor phenomena, 11.9% of autonomic findings, and 2.1% of postictal impairments were recalled. The ability to recall seizure elements varied significantly depending on seizure types (secondarily generalized tonic-clonic seizures [SGTCS] < complex partial seizures [CPS] < simple partial seizures [SPS]), but not on the relative timing of the element during the seizure.

Patients' memory of seizure semiology is almost always fragmentary. Although the rate of correctly remembered seizure elements depends on the seizure type, complete recall of a seizure is almost never obtained. Consequently, 89 of 90 patients in this cohort would only have had seizures classified as a seizure with "impaired awareness" according to the new International League Against Epilepsy (ILAE) seizure classification. The involvement of brain areas involved in memory encoding and consolidation and in the context of seizure classification schemes.