Diagnostic yield of high-density versus low-density EEG: The effect of spatial sampling, timing and duration of recording

TY - JOUR

T1 - Diagnostic yield of high-density versus low-density EEG

T2 - The effect of spatial sampling, timing and duration of recording

AU - Bach Justesen, Anders

AU - Foged, Mette Thrane

AU - Fabricius, Martin

AU - Skaarup, Christian

AU - Hamrouni, Nizar

AU - Martens, Terje

AU - Paulson, Olaf B.

AU - Pinborg, Lars H.

AU - Beniczky, Sándor

PY - 2019

Y1 - 2019

N2 - Objective: To investigate the effect of spatial sampling and of recording duration on the diagnostic yield of EEG for identification of interictal epileptiform discharges (IEDs). Previous studies demonstrated that high-density (HD) recordings increased accuracy of localization compared to low-density (LD) recordings. Methods: We have prospectively evaluated the effect of spatial sampling and of recording duration in patients who had short-term (ST) recordings with a HD array of 256 electrodes following long-term (LT) recordings with a LD array consisting of the standard IFCN array of 25 electrodes. IED clusters were identified in four datasets: LT-LD, ST-LD (spatially down-sampled to the standard IFCN array), ST-HD and a shortened (90 minutes) epoch of LT-LD. Results: Sixty consecutive patients were recruited. We identified 89 IED clusters totally. Two clusters were found by increasing spatial sampling from 25 to 256 electrodes. This modest increase was not statistically significant. Eight clusters were missed by reducing the recording duration to 90 minutes, as compared with the LT recordings (p = 0.003). Conclusions: Recording duration is more important for the diagnostic yield of EEGs than increasing spatial sampling beyond the standard IFCN electrode array. Significance: The standard IFCN electrode array provides sufficient spatial sampling for identification of the IEDs.

AB - Objective: To investigate the effect of spatial sampling and of recording duration on the diagnostic yield of EEG for identification of interictal epileptiform discharges (IEDs). Previous studies demonstrated that high-density (HD) recordings increased accuracy of localization compared to low-density (LD) recordings. Methods: We have prospectively evaluated the effect of spatial sampling and of recording duration in patients who had short-term (ST) recordings with a HD array of 256 electrodes following long-term (LT) recordings with a LD array consisting of the standard IFCN array of 25 electrodes. IED clusters were identified in four datasets: LT-LD, ST-LD (spatially down-sampled to the standard IFCN array), ST-HD and a shortened (90 minutes) epoch of LT-LD. Results: Sixty consecutive patients were recruited. We identified 89 IED clusters totally. Two clusters were found by increasing spatial sampling from 25 to 256 electrodes. This modest increase was not statistically significant. Eight clusters were missed by reducing the recording duration to 90 minutes, as compared with the LT recordings (p = 0.003). Conclusions: Recording duration is more important for the diagnostic yield of EEGs than increasing spatial sampling beyond the standard IFCN electrode array. Significance: The standard IFCN electrode array provides sufficient spatial sampling for identification of the IEDs.

KW - Diagnostic yield

KW - Duration

KW - EEG

KW - High-density array

KW - Interictal epileptiform discharges

KW - Spatial sampling

U2 - 10.1016/j.clinph.2019.08.007

DO - 10.1016/j.clinph.2019.08.007

M3 - Journal article

C2 - 31541983

AN - SCOPUS:85072240797

SN - 1388-2457

VL - 130

SP - 2060

EP - 2064

JO - Clinical Neurophysiology

JF - Clinical Neurophysiology

IS - 11

ER -