Interrater reliability in interpretation of electrocorticographic seizure detections of the responsive neurostimulator. (20th April 2015)

• Record Type: Journal Article
• Authors: Quigg, Mark; Sun, Felice; Fountain, Nathan B.; Jobst, Barbara C.; Wong, Victoria S. S.; Mirro, Emily; Brown, Sarah; Spencer, David C.
• Is Part Of: Epilepsia. Volume 56:issue 6(2015:Jun.)
• Page Start: 968
• Page End: 971
• Publication Date: 2015-04-20
• Subjects: Epilepsy -- Periodicals; 616.853
• DOI: 10.1111/epi.12998
• Languages: English
• ISSNs: 0013-9580

Abstract

<abstract abstract-type="main" id="epi12998-abs-0001"> <title>Summary</title> <sec id="epi12998-sec-0001" sec-type="section"> <title>Objective</title> <p>Electrocorticographic (ECoG) recordings from patients with medically intractable partial‐onset seizures treated with a responsive neurostimulator system (the RNS System) that detects and stores physician‐specified ECoG events provide a new data resource. Interpretation of these recordings has not yet been validated. The purpose was to evaluate the interrater interpretation of chronic ambulatory ECoG recordings obtained by the RNS System.</p> </sec> <sec id="epi12998-sec-0002" sec-type="section"> <title>Methods</title> <p>Five pairs of five experts independently classified 7, 221 ECoG recordings obtained from 128 patients with medically intractable partial seizures who participated in a randomized controlled trial of the safety and efficacy of the RNS System. ECoG detections—"long episodes" or "saturations"—were classified as "seizures" or "not seizures" based on a reference definition. Interrater agreement rates and kappa score reliabilities were calculated between rater pairs from the ECoG sample as a whole and within individual patients who had more than the median number of individual ECoG recordings.</p> </sec> <sec id="epi12998-sec-0003" sec-type="section"> <title>Results</title> <p>The overall interrater agreement was 79%, with a reliability κ = 0.57 (moderate agreement). Agreement between pairs of reviewers ranged from 0.69 to 0.85. Agreement rates were 94% or better for 50% of patients. Only 25% of patients had ECoG recordings agreement rates worse than 75%. ECoGs with mixed interpretations (one reviewer "seizure"/the other—"not seizure") consisted of periods of low amplitude activity that evolved in amplitude or periodic discharges near 2 Hz.</p> </sec> <sec id="epi12998-sec-0004" sec-type="section"> <title>Significance</title> <p>Although reliability as a whole was moderate, for the majority of patients, detections yielded highly reliably interpreted events of either electrographic seizures or nonictal epileptiform activity.</p> </sec> </abstract>