PURPOSE: Two subtypes of temporal lobe epilepsy (TLE) can be defined through clinical observations and analysis of hippocampal tissue resected during surgical procedures for intractable TLE: (a) mesial temporal sclerosis (MTS), which is characterized by extensive changes to the hippocampus and good surgical outcome; and (b) paradoxical temporal lobe epilepsy (PTLE), which is characterized by minimal cell loss and comparatively poorer surgical outcome. Patients in both subtypes have seizures that appear to begin in the medial temporal lobe, but documented differences in substrate and outcome between these subtypes has defined a need to distinguish MTS and PTLE patients before surgery. This report describes a retrospective study to investigate the feasibility of doing so during intracranial monitoring. METHODS: Background EEG epochs, 5 min in duration, were recorded from the anterior hippocampus in 14 (10 MTS and four PTLE) patients with consistent localization of seizure onset to medial temporal structures. The power spectral density (PSD) of the EEG epochs was calculated by a Fourier spectral estimator, and the total signal power and power of the delta, theta, alpha, beta, and gamma frequency bands were submitted to group-to-group comparison. RESULTS: Spectral peaks were observed in the delta band in all PSD estimates and in the theta band in nine of 14 (seven MTS, two PTLE) estimates. The MTS and PTLE subtypes could be distinguished by the total signal power and delta band power. These power measurements were greater in the PTLE subtype. CONCLUSIONS: Both delta and theta spectral components are present in hippocampal background EEGs recorded from patients with TLE. The results indicate that group differences exist in spectral measures of background hippocampal signals recorded from MTS and PTLE subtypes. This suggests both that substrate differences in cellular composition and connectivity are reflected in hippocampal background EEGs and that spectral measurements of these signals may hold promise for tests to identify the group membership of individual patients.
PURPOSE: Two subtypes of temporal lobe epilepsy (TLE) can be defined through clinical observations and analysis of hippocampal tissue resected during surgical procedures for intractable TLE: (a) mesial temporal sclerosis (MTS), which is characterized by extensive changes to the hippocampus and good surgical outcome; and (b) paradoxical temporal lobe epilepsy (PTLE), which is characterized by minimal cell loss and comparatively poorer surgical outcome. Patients in both subtypes have seizures that appear to begin in the medial temporal lobe, but documented differences in substrate and outcome between these subtypes has defined a need to distinguish MTS and PTLE patients before surgery. This report describes a retrospective study to investigate the feasibility of doing so during intracranial monitoring. METHODS: Background EEG epochs, 5 min in duration, were recorded from the anterior hippocampus in 14 (10 MTS and four PTLE) patients with consistent localization of seizure onset to medial temporal structures. The power spectral density (PSD) of the EEG epochs was calculated by a Fourier spectral estimator, and the total signal power and power of the delta, theta, alpha, beta, and gamma frequency bands were submitted to group-to-group comparison. RESULTS: Spectral peaks were observed in the delta band in all PSD estimates and in the theta band in nine of 14 (seven MTS, two PTLE) estimates. The MTS and PTLE subtypes could be distinguished by the total signal power and delta band power. These power measurements were greater in the PTLE subtype. CONCLUSIONS: Both delta and theta spectral components are present in hippocampal background EEGs recorded from patients with TLE. The results indicate that group differences exist in spectral measures of background hippocampal signals recorded from MTS and PTLE subtypes. This suggests both that substrate differences in cellular composition and connectivity are reflected in hippocampal background EEGs and that spectral measurements of these signals may hold promise for tests to identify the group membership of individual patients.
Authors: Andrew J Watrous; Darrin J Lee; Ali Izadi; Gene G Gurkoff; Kiarash Shahlaie; Arne D Ekstrom Journal: Hippocampus Date: 2013-04-29 Impact factor: 3.899
Authors: Sean N Hatton; Khoa H Huynh; Leonardo Bonilha; Eugenio Abela; Saud Alhusaini; Andre Altmann; Marina K M Alvim; Akshara R Balachandra; Emanuele Bartolini; Benjamin Bender; Neda Bernasconi; Andrea Bernasconi; Boris Bernhardt; Núria Bargallo; Benoit Caldairou; Maria E Caligiuri; Sarah J A Carr; Gianpiero L Cavalleri; Fernando Cendes; Luis Concha; Esmaeil Davoodi-Bojd; Patricia M Desmond; Orrin Devinsky; Colin P Doherty; Martin Domin; John S Duncan; Niels K Focke; Sonya F Foley; Antonio Gambardella; Ezequiel Gleichgerrcht; Renzo Guerrini; Khalid Hamandi; Akari Ishikawa; Simon S Keller; Peter V Kochunov; Raviteja Kotikalapudi; Barbara A K Kreilkamp; Patrick Kwan; Angelo Labate; Soenke Langner; Matteo Lenge; Min Liu; Elaine Lui; Pascal Martin; Mario Mascalchi; José C V Moreira; Marcia E Morita-Sherman; Terence J O'Brien; Heath R Pardoe; José C Pariente; Letícia F Ribeiro; Mark P Richardson; Cristiane S Rocha; Raúl Rodríguez-Cruces; Felix Rosenow; Mariasavina Severino; Benjamin Sinclair; Hamid Soltanian-Zadeh; Pasquale Striano; Peter N Taylor; Rhys H Thomas; Domenico Tortora; Dennis Velakoulis; Annamaria Vezzani; Lucy Vivash; Felix von Podewils; Sjoerd B Vos; Bernd Weber; Gavin P Winston; Clarissa L Yasuda; Alyssa H Zhu; Paul M Thompson; Christopher D Whelan; Neda Jahanshad; Sanjay M Sisodiya; Carrie R McDonald Journal: Brain Date: 2020-08-01 Impact factor: 13.501
Authors: Sanjay M Sisodiya; Christopher D Whelan; Sean N Hatton; Khoa Huynh; Andre Altmann; Mina Ryten; Annamaria Vezzani; Maria Eugenia Caligiuri; Angelo Labate; Antonio Gambardella; Victoria Ives-Deliperi; Stefano Meletti; Brent C Munsell; Leonardo Bonilha; Manuela Tondelli; Michael Rebsamen; Christian Rummel; Anna Elisabetta Vaudano; Roland Wiest; Akshara R Balachandra; Núria Bargalló; Emanuele Bartolini; Andrea Bernasconi; Neda Bernasconi; Boris Bernhardt; Benoit Caldairou; Sarah J A Carr; Gianpiero L Cavalleri; Fernando Cendes; Luis Concha; Patricia M Desmond; Martin Domin; John S Duncan; Niels K Focke; Renzo Guerrini; Khalid Hamandi; Graeme D Jackson; Neda Jahanshad; Reetta Kälviäinen; Simon S Keller; Peter Kochunov; Magdalena A Kowalczyk; Barbara A K Kreilkamp; Patrick Kwan; Sara Lariviere; Matteo Lenge; Seymour M Lopez; Pascal Martin; Mario Mascalchi; José C V Moreira; Marcia E Morita-Sherman; Heath R Pardoe; Jose C Pariente; Kotikalapudi Raviteja; Cristiane S Rocha; Raúl Rodríguez-Cruces; Margitta Seeck; Mira K H G Semmelroch; Benjamin Sinclair; Hamid Soltanian-Zadeh; Dan J Stein; Pasquale Striano; Peter N Taylor; Rhys H Thomas; Sophia I Thomopoulos; Dennis Velakoulis; Lucy Vivash; Bernd Weber; Clarissa Lin Yasuda; Junsong Zhang; Paul M Thompson; Carrie R McDonald Journal: Hum Brain Mapp Date: 2020-05-29 Impact factor: 5.038