Daniel E Payne1,2, Philippa J Karoly1,2, Dean R Freestone2, Ray Boston2, Wendyl D'Souza2, Ewan Nurse1,2, Levin Kuhlmann1,2,3, Mark J Cook1,2, David B Grayden1,2. 1. Department of Biomedical Engineering, Melbourne School of Engineering, The University of Melbourne, Parkville, Vic., Australia. 2. Department of Medicine, St Vincent's Hospital, The University of Melbourne, Fitzroy, Vic., Australia. 3. Brain Dynamics Unit, Centre for Human Psychopharmacology, Swinburne University of Technology, Hawthorn, Vic., Australia.
Abstract
OBJECTIVE: We report on patient-specific durations of postictal periods in long-term intracranial electroencephalography (iEEG) recordings. The objective was to investigate the relationship between seizure duration and postictal suppression duration. METHODS: Long-term recording iEEG from 9 patients (>50 seizures recorded) were analyzed. In total, 2310 seizures were recorded during a total of 13.8 years of recording. Postictal suppression duration was calculated as the duration after seizure termination until total signal energy returned to background levels. The relationship between seizure duration and postictal suppression duration was quantified using the correlation coefficient (r). The effects of populations of seizures within patients, on correlations, were also considered. Populations of seizures within patients were distinguished by seizure duration thresholds and k-means clustering along the dimensions of seizure duration and postictal suppression duration. The effects of bursts of seizures were also considered by defining populations based on interseizure interval (ISI). RESULTS: Seizure duration accounted for 40% of postictal suppression duration variance, aggregated across all patients and seizures. Seizure duration accounted for more than 25% of the variance in postictal suppression duration in 2 patients and accounted for less than 25% in the remaining 7. In 3 patients, heat maps showed multiple distinct postictal patterns indicating multiple populations of seizures. When accounting for these populations, seizure duration accounted for less than 25% of the variance in postictal duration in all populations. Variance in postictal suppression duration accounted for less than 10% of ISI variance in all patients. SIGNIFICANCE: We have previously demonstrated that some patients have multiple seizure populations distinguishable by seizure duration. This article shows that different seizure populations have distinct and consistent postictal behaviors. The existence of multiple populations in some patients has implications for seizure management and forecasting, whereas the distinct postictal behaviors may have implications for sudden unexpected death in epilepsy (SUDEP) prediction and prevention. Wiley Periodicals, Inc.
OBJECTIVE: We report on patient-specific durations of postictal periods in long-term intracranial electroencephalography (iEEG) recordings. The objective was to investigate the relationship between seizure duration and postictal suppression duration. METHODS: Long-term recording iEEG from 9 patients (>50 seizures recorded) were analyzed. In total, 2310 seizures were recorded during a total of 13.8 years of recording. Postictal suppression duration was calculated as the duration after seizure termination until total signal energy returned to background levels. The relationship between seizure duration and postictal suppression duration was quantified using the correlation coefficient (r). The effects of populations of seizures within patients, on correlations, were also considered. Populations of seizures within patients were distinguished by seizure duration thresholds and k-means clustering along the dimensions of seizure duration and postictal suppression duration. The effects of bursts of seizures were also considered by defining populations based on interseizure interval (ISI). RESULTS:Seizure duration accounted for 40% of postictal suppression duration variance, aggregated across all patients and seizures. Seizure duration accounted for more than 25% of the variance in postictal suppression duration in 2 patients and accounted for less than 25% in the remaining 7. In 3 patients, heat maps showed multiple distinct postictal patterns indicating multiple populations of seizures. When accounting for these populations, seizure duration accounted for less than 25% of the variance in postictal duration in all populations. Variance in postictal suppression duration accounted for less than 10% of ISI variance in all patients. SIGNIFICANCE: We have previously demonstrated that some patients have multiple seizure populations distinguishable by seizure duration. This article shows that different seizure populations have distinct and consistent postictal behaviors. The existence of multiple populations in some patients has implications for seizure management and forecasting, whereas the distinct postictal behaviors may have implications for sudden unexpected death in epilepsy (SUDEP) prediction and prevention. Wiley Periodicals, Inc.
Authors: Levin Kuhlmann; Philippa Karoly; Dean R Freestone; Benjamin H Brinkmann; Andriy Temko; Alexandre Barachant; Feng Li; Gilberto Titericz; Brian W Lang; Daniel Lavery; Kelly Roman; Derek Broadhead; Scott Dobson; Gareth Jones; Qingnan Tang; Irina Ivanenko; Oleg Panichev; Timothée Proix; Michal Náhlík; Daniel B Grunberg; Chip Reuben; Gregory Worrell; Brian Litt; David T J Liley; David B Grayden; Mark J Cook Journal: Brain Date: 2018-09-01 Impact factor: 13.501
Authors: Daniel E Payne; Katrina L Dell; Phillipa J Karoly; Vaclav Kremen; Vaclav Gerla; Levin Kuhlmann; Gregory A Worrell; Mark J Cook; David B Grayden; Dean R Freestone Journal: Epilepsia Date: 2020-12-30 Impact factor: 6.740
Authors: Emmanouil Giannakakis; Frances Hutchings; Christoforos A Papasavvas; Cheol E Han; Bernd Weber; Chencheng Zhang; Marcus Kaiser Journal: PLoS One Date: 2020-02-06 Impact factor: 3.240
Authors: Philippa J Karoly; Levin Kuhlmann; Daniel Soudry; David B Grayden; Mark J Cook; Dean R Freestone Journal: PLoS Comput Biol Date: 2018-10-11 Impact factor: 4.475