Abstracts

Rationale: To compare EEG recording with both anterior temporal (ATE) and nasopharyngeal electrode (NPE) (NPE recording) with EEG recording with only ATE (non-NPE recording) for the detection of interictal epileptiform discharges (IEDs) and bilateral independent IEDs in patients with temporal lobe epilepsy (TLE). Methods: We retrospectively analyzed the initial EEGs which were recorded simultaneously with ATE and NPE in addition to 10-20 system electrodes in 229 patients with TLE. Two data sets of NPE and non-NPE recordings were reviewed independently by three interpreters with different experience. Discordant findings in interpretation among three interpreters were corrected by a consensus through elaborate review of EEG recordings, resulting in final results. Results: Diagnostic sensitivity of IEDs in NPE/non-NPE recording was 60.3%/27.1% in beginner, 69.0%/49.8% in junior expert, and 74.2%/52.0% in senior expert. In the final results, IEDs were detected in 76.4% with NPE compared to 55.5% with non-NPE (p < 0.001). Bilateral IEDs/EEG recording of detected IEDs were found in 26/127 with non-NPE and 60/175 with NPE (p < 0.001). Diagnostic yield of NPE for the detection of IEDs was significantly increased in mesial and non-lesional TLEs. Agreement degree for the detection of IEDs among three interpreters in NPE was higher than that in non-NPE (κappa score 0.703 versus 0.536). Conclusions: EEG recording by using NPE in combination with the standard electrodes and ATE may improve the sensitivity and the level of agreement in the detection of IEDs in TLE regardless of different experience of EEG interpretation. Furthermore, application of NPE could enhance the detection of bilateral IEDs. Funding: No funding