Video-ambulatory EEG in a secondary care center: A retrospective evaluation of utility in the diagnosis of epileptic and nonepileptic seizures

The development and optimization of protocols using simultaneous video recording alongside long-term electroencephalography (EEG), such as ambulatory EEG (AEEG), expanded the range of available techniques for the investigation of paroxysmal clinical events. In particular, video-AEEG has received increasing attention over the last few years because of its potential to further improve diagnostic utility in the differential diagnosis between epileptic and nonepileptic seizures. We retrospectively evaluated 88 video-AEEG studies in order to assess the diagnostic utility of video-AEEG in 87 patients consecutively referred to a neurophysiology department. Typical clinical events occurred during 55 studies (62.5%). In 26 of these, at least one event was also clearly seen on video recording, contributing to a confident diagnosis. Clinical events were classified according to three diagnostic categories: epileptic seizures (6 studies, 6.8%), physiologic nonepileptic events (13 studies, 14.8%), or psychogenic nonepileptic seizures (36 studies, 40.9%). Of the studies with an event not recorded on video, a confident diagnosis could be reached in 55.2% of cases. The main reason for unsuccessful video recording was failure to activate the camcorder by the patient or carer. We found an overall diagnostic utility of 67.0%, which confirms the findings of previous reports evaluating the diagnostic yield of AEEG. Implementation of video-AEEG protocols in a secondary care center appears to have high diagnostic utility, particularly for patients with psychogenic nonepileptic seizures. Our findings prompt further research into the potential applications of video-AEEG, in consideration of important implications for successful patient management and healthcare resource allocation.