The value of surface sphenoidal electrode in detecting interictal abnormal discharge in temporal region / 中华神经科杂志

ABSTRACT

Objective:To compare the detection and amplitude of epileptiform discharges (EDs) between surface sphenoidal electrode and anterior temporal electrode in patients with interictal EDs in the temporal region, and to explore the value of surface sphenoidal electrode.Methods:A total of 1 356 outpatients with epilepsy who underwent 2-hour video electroencephalogram (EEG) monitoring in Xuanwu Hospital from October to December 2021 were retrospectively enrolled. All patients were hooked up with scalp electrode according to the international 10-20 system as well as surface sphenoidal electrode and anterior temporal electrode. The EEGs with EDs recorded by surface sphenoidal electrode and/or anterior temporal electrode were selected for analysis. The detection rate and the amplitude of EDs by surface sphenoidal electrode and anterior temporal electrode were compared.Results:Seventy-three EEGs were collected and 250 EDs were counted. The detection rate of the anterior temporal electrode and surface sphenoidal electrode were 88.0% (220/250) and 98.4% (246/250) respectively. The difference in detection rate was statistically significant (χ 2=18.38, P<0.001). For the EDs from anterior temporal regions (taking the discharges recorded by anterior temporal electrode as "gold standard"), the detection rate of surface sphenoidal electrode was 98.2% (216/220). There was no statistically significant difference in detection rate between the anterior temporal electrode and surface sphenoidal electrode (χ 2=2.27, P=0.132). There were 216 EDs recorded by these two kinds of electrode simultaneously. The average amplitude of the EDs on surface sphenoidal electrode and anterior temporal electrode was (77.1±38.9) μV and (80.2±44.9) μV, respectively. The difference was statistically significant ( t=2.28, P=0.031). Conclusions:The detection rate of surface sphenoid electrodes was higher than that of anterior temporal electrodes for the EDs in the temporal region, and surface sphenoidal electrodes can be used routinely in outpatient. The surface sphenoidal electrode had more chance to detect EDs originating from regions out of the anterior temporal regions.