Outpatient Seizure Identification

Abstract

Patients with epilepsy may not always be able to identify their seizures. Epilepsy management relies on patient reporting to validate whether seizures occur during treatment. The goal of this study was to assess the frequency of unreported seizures recorded during routine outpatient ambulatory EEG recording. The authors reviewed 552 records from 502 patients who underwent outpatient 16-channel computer-assisted ambulatory EEG monitoring (CAA-EEG). Seizure identification was evaluated by assessing push-button activation. Partial seizures were seen most commonly. A total of 47 of 552 records (8.5%) had partial seizures recorded on CAA-EEG, with 29 of 47 (61.7%) with electroclinical seizures identified by push-button activation. Seizures on EEG without push-button activation were analyzed separately and compared with a self-reported written diary to verify lack of recognition. A total of 18 of 47 records (38.3%) had some partial seizures that were unrecognized by the patient, and 11 of 47 records (23.4%) had seizures recognized only by the computer. The authors conclude that patients frequently have seizures outside of the hospital that go unrecognized. Underreporting of seizure frequency occurs in the outpatient setting and impacts optimal diagnosis and treatment for patients with epilepsy.

Functional definition of seizure provides new insight into post-traumatic epileptogenesis

“…The observation of brief stereotyped recurrent abnormal behaviour in patients at risk of developing epilepsy is considered a tell-tale sign of the condition (Beghi et al ., 2005; Fisher et al ., 2005). However, complex partial seizures—the seizure type for which novel treatments are most needed (Juul-Jensen, 1986; Mattson et al ., 1985; 1996; Semah et al ., 1998)—often present subtly with staring, memory lapses, muscle twitching or impairment in normal function that may go unrecognized by both patients and physicians (Blum et al ., 1996; Tatum et al ., 2001), and can be virtually impossible to detect in animals. Indeed, before diagnosis is confirmed by scalp encephalography (EEG), human complex partial seizures are often first identified through either the patients’ altered state of consciousness or their self-reported internal subjective experience, information not obtainable from animals.…”

Consciousness of seizures and consciousness during seizures: Are they related?

“…The effect of therapeutic intervention is measured by patient seizure counts. Based on previous studies, it has been noted that patients do not report up to half of their seizures [14–18]. Such underreporting may undermine the everyday care of patients with epilepsy.…”

“…The accuracy of patient report about their seizures has been studied in the form of diaries or seizure counts mostly during inpatient video-EEG monitoring. Surprisingly, overall, patients do not report 30–50% of their seizures [14–18]. This has obvious consequences for patient care and the accuracy of clinical drug trials.…”

“…These include the following: seizure localization by hemisphere and lobe, preictal vigilance state at time of seizure onset, memory function, and seizure type [14–18]. Seizure type, in turn, determines whether patients are conscious during seizures.…”

Ambulatory electroencephalogram in children: A prospective clinical audit of 100 cases

“…[23] One study also reported its application in adults when under reporting of seizure frequency was suspected, to optimize the treatment. [5] It has also been used to help in identifying patients at low risk of recurrent seizures, among the patients presenting with infrequent seizures prior to drug treatment. [6] It has also been used to quantify paroxysmal discharges in patients with typical absence epilepsies by a limited recording over 8 h.[7]…”