Diagnostic utility of long-term ambulatory video electroencephalography monitoring.

Abstract

Objectives Ambulatory video electroencephalography (A-VEEG) represents a low-cost, convenient and accessible alternative to inpatient VEEG monitoring, however few studies have examined their diagnostic yield. In this large-scale Australian study, we evaluated the efficacy of long-term A-VEEG recordings in capturing diagnostic events and addressing the referring ques-tion(s). Methods Adult and paediatric A-VEEG reports from January 2020 to June 2021 were reviewed retrospectively. Diagnostic utility was explored by examining i) time of first diagnostic event, and ii) ability to address the referring question(s)-seizure localisation, quantification, classification, and/or differentiation (differentiating epileptic from non-epileptic events). Results 600 reports were analysed, ranging 1-10 days duration (mean=5.7). At least one event was captured in 46% of recordings. 13% captured epileptic events and 36% captured events without electrographic changes. Unrecognised events were captured in 52 recordings, and were mostly (81%) epileptic events. 9% of events were not classified due to absence of clinical, video or electrographic data. 234 recordings (39%) captured a diagnostic event, of which 96% were first captured within the initial five days of recording. 85% of reports with at least one event (and 52% of all reports) captured diagnostic events and/or electro-graphic changes which unequivocally addressed the referrer's question(s). Specifically, this represented 75% of reports (27/36) regarding classification of seizures, and 46% of reports (235/515) regarding differentiation of events. 45% of studies captured interictal abnormalities; in their absence, almost all seizure-like events (96%) were non-epileptic in nature. Conclusions A-VEEG recordings were of high quality and diagnostic value in capturing clinically relevant events.