Effect of Detection Parameters on Automated Electroencephalography Spike Detection Sensitivity and False-Positive Rate

PURPOSE: Most seizure monitoring units use the Gotman algorithm or a variation on it for EEG spike detection, but the effect of various detection parameters on its accuracy has not been well established. The authors report sensitivities and false-positive rates for several different sets of detection parameters. METHODS: Nine patients were studied. For each patient, 6 hours of EEG data were analyzed using five different sets of spike detection parameters including combinations of amplitude thresholds, state-dependent spike detection and advanced artifact rejection. Automated spike detections were compared with spikes found on visual EEG review. RESULTS: Mean spike detection sensitivities for the different parameter sets ranged from 0.09 to 0.34. The highest sensitivity occurred with an amplitude threshold of 4, state-dependent spike detection turned on and advanced artifact rejection turned off. Mean rates of false-positives ranged from 4.2 to 48.6 per hour. The highest false-positive rate occurred with the same set of detection parameters that produced the highest sensitivity. CONCLUSIONS: The sensitivity of spike detection with the Gotman algorithm is relatively low. The data favor using a lower amplitude threshold and not using advanced artifact rejection. The false-positive rate increases with improved sensitivity, but it is still within an acceptable range for clinical application.