Diagnostic Accuracy of Ambulatory EEG vs Routine EEG in Patients With First Single Unprovoked Seizure

Abstract

Background and ObjectiveTo evaluate the diagnostic accuracy of the ambulatory EEG (aEEG) at detecting interictal epileptiform discharges (IEDs)/seizures compared with routine EEG (rEEG) and repetitive/second rEEG in patients with a first single unprovoked seizure (FSUS). We also evaluated the association between IED/seizures on aEEG and seizure recurrence within 1 year of follow-up.MethodsWe prospectively evaluated 100 consecutive patients with FSUS at the provincial Single Seizure Clinic. They underwent 3 sequential EEG modalities: first rEEG, second rEEG, and aEEG. Clinical epilepsy diagnosis was ascertained based on the 2014 International League Against Epilepsy definition by a neurologist/epileptologist at the clinic. An EEG-certified epileptologist/neurologist interpreted all 3 EEGs. All patients were followed up for 52 weeks until they had either second unprovoked seizure or maintained single seizure status. Accuracy measures (sensitivity, specificity, negative and positive predictive values, and likelihood ratios), receiver operating characteristic (ROC) analysis, and area under the curve (AUC) were used to evaluate the diagnostic accuracy of each EEG modality. Life tables and the Cox proportional hazard model were used to estimate the probability and association of seizure recurrence.ResultsAmbulatory EEG captured IED/seizures with a sensitivity of 72%, compared with 11% for the first rEEG and 22% for the second rEEG. The diagnostic performance of the aEEG was statistically better (AUC: 0.85) compared with the first rEEG (AUC: 0.56) and second rEEG (AUC: 0.60). There were no statistically significant differences between the 3 EEG modalities regarding specificity and positive predictive value. Finally, IED/seizure on the aEEG was associated with more than 3 times the hazard of seizure recurrence.DiscussionThe overall diagnostic accuracy of aEEG at capturing IED/seizures in people presenting with FSUS was higher than the first and second rEEGs. We also found that IED/seizures on the aEEG were associated with an increased risk of seizure recurrence.Classification of EvidenceThis study provides Class I evidence supporting that, in adults with First Single Unprovoked Seizure (FSUS), 24-h ambulatory EEG has increased sensitivity when compared with routine and repeated EEG.

Computer-assisted analysis of routine EEG to identify hidden biomarkers of epilepsy: A systematic review

“…Because of its relatively low signal-to-noise ratio, EEG data is subject to high variability induced by the recording setting, apparel, and even patient-related characteristics (e.g., hair, muscle activation, eye movements). [101] , [102] , [103] In future studies, large-scale initiatives integrating rEEG recordings from multiple centers along with a more widespread use of ambulatory EEG as a diagnostic tool in patients with first unprovoked seizures [104] will likely amplify this challenge. Automated methods for artifact detection and rejection based on deep neural networks are promising alternatives to manual identification, [105] , [106] , [107] but their capacity to increase downstream performances remains unclear.…”

Current state of the epilepsy drug and device pipeline

“…Diagnostic accuracy is higher with longer EEG monitoring, 62 although prolonged ambulatory monitoring is limited with conventional EEG equipment. The REMI remote EEG monitoring system by Epitel uses four, single‐patient, single‐use wireless sensors that transmit a single‐channel EEG to a mobile computing device and uses automated seizure detection with machine learning to tag events for clinician review.…”

Get Out the Door: Ambulatory EEG Trumps Routine EEG in the Detection of Interictal Epileptiform Abnormalities After a First Unprovoked Seizure

“…1 The true risk is what happens in actuality, and the aEEG seems more accurate in predicting the true risk. 4 It is important to note that ASM treatment does not change the long-term risk of second unprovoked seizure and epilepsy. 1 An interesting finding in the study cohort was that older adults (>60 years) were more likely to have recurrent seizures.…”

“…In this vacuum, the study by Hernandez-Ronquillo et al lands with a thunderous bang in favor of ambulatory EEG. 4 This elegant study performed prospectively over 4 years aimed to evaluate the yield of aEEG compared to a first and a repeat rEEG for detecting IEDs/seizures after FSUS. The study cohort had ages between 17 and 82 years, but racial distribution was not disclosed.…”

“… 1 The true risk is what happens in actuality, and the aEEG seems more accurate in predicting the true risk. 4 It is important to note that ASM treatment does not change the long-term risk of second unprovoked seizure and epilepsy. 1 …”