Hippocampal involvement in secondarily generalised seizures of extrahippocampal origin

Surges, R; Schulze-Bonhage, A; Altenm├╝ller, D-M
August 2008
Journal of Neurology, Neurosurgery & Psychiatry;Aug2008, Vol. 79 Issue 8, p924
Academic Journal
Background and aims: Recent data have revealed that clinically generalised tonic-clonic seizures do not involve all brain regions electrophysiologically. The hippocampus in particular could be protected from epileptic activity by putative filtering properties of the dentate gyrus. Here we investigated if simple or complex focal seizures (SFS/CFS) and in particular secondarily generalised tonic-clonic seizures (SGS) of extrahippocampal onset (EHO) spare the hippocampus and if there are promotive factors. Methods: We retrospectively assessed clinical, electro- physiological, imaging and histopathological data from patients undergoing presurgical evaluation of focal epilepsy with hippocampal depth and extrahippocampal subdural electrodes and selected those suffering from SOS of EHO. We further subdivided this patient sample according to qualitative MRI criteria into a HL(-) group, with an extrahippocampal lesion only, and a HL(+) group, displaying an extrahippocampal and additional hippocampal lesion. Results: 14 patients (seven in each group) fulfilling the inclusion criteria had a total of 43 SOS, of which 35 were of [HO. Whereas only 68% of SFSICFS of EHO propagated into the hippocampus, all SOS of EHO invaded the hippocampi independently of the ictal propagation pattern or degree of hippocampal pathology. All hippocampi in the HL)-) group displayed interictal epileptiform activity and even seizure onset in two patients. Conclusions: In our patient sample, the human hippocampus was not spared during SOS of EHO, but was invariably invaded by epileptic activity. The presence of spontaneous epileptic activity in the HL)-) group revealed persistent modifications in hippocampal excitability that might be due to secondary epileptogenesis in the hippocampus following repeated seizures of [HO.


Related Articles

  • EEG (ELECTROENCEPHALOGRAPHY). TATUM IV, WILLIAM O.; KAPLAN, PETER W.; JALLON, PIERRE // Epilepsy A to Z: A Concise Encyclopedia;2009, p105 

    An encyclopedia entry for "EEG (electroencephalography)" is presented. It states that EEG has played a significant role in the evaluation of seizures and is composed of an amplified electrical signal derived from cerebral neuronal activity. It notes that EEG also offers information on the...

  • Long-Term Seizure Monitoring Using a 256 Contact Dense Array System. Thompson, Paul; Rae, Julie; Weber, Leigh; Pearson, Christopher; Goldeshtein, Zoe; Holmes, Mark D. // American Journal of Electroneurodiagnostic Technology;Jun2008, Vol. 48 Issue 2, p93 

    Adapting a 256 contact dense array system to perform multiday long-term EEG and video monitoring requires additional technical attention compared to standard long-term monitoring (LTM). Areas of concern are patient comfort, electrode maintenance, and increased time for record review.

  • Nonlinear dynamics in EEG from epileptic patients: Is it possible to predict seizures? Winterhalder, M.; Schelter, B.; Maiwald, T.; Aschenbrenner-Scheibe, R.; Brandt, A.; Schulze-Bonhage, A.; Timmer, J. // AIP Conference Proceedings;2004, Vol. 742 Issue 1, p216 

    Several concepts and analysis techniques originating from Nonlinear Dynamics have been applied to electroencephalography recordings of epilepsy patients to predict seizures. An early prediction of an upcoming seizure would dramatically increase the therapeutic possibilities for this common...

  • Local and remote epileptogenicity in focal cortical dysplasias and neurodevelopmental tumours. Aubert, Sandrine; Wendling, Fabrice; Regis, Jean; McGonigal, Aileen; Figarella-Branger, Dominique; Peragut, Jean-Claude; Girard, Nadine; Chauvel, Patrick; Bartolomei, Fabrice // Brain: A Journal of Neurology;Nov2009, Vol. 132 Issue 11, p3072 

    During the pre-surgical evaluation of drug-resistant epilepsy, the assessment of the extent of the epileptogenic zone and its organization is a crucial objective. Indeed, the epileptogenic zone may be organized as a simple focal lesional site or as a more complex network (often referred to as...

  • Clinical cues for detecting ictal asystole. Ghearing, Gena R.; Munger, Thomas M.; Jaffe, Allan S.; Benarroch, Eduardo E.; Britton, Jeffrey W. // Clinical Autonomic Research;Aug2007, Vol. 17 Issue 4, p221 

    The occurrence of asystole during an epileptic seizure is the most dramatic manifestation of ictal bradycardia. Recognition of ictal asystole is important as treatment with both antiepileptic drugs and cardiac pacing may be necessary. The purpose of this study was to identify clinical cues to...

  • Medically refractory epilepsy associated with focal cortical dysplasias: clinical, electrophysiologic, imaging and pathologic characteristics and seizure outcome. Singh, Atam Preet; Radhakrishnan, Ashalatha; Radhakrishnan, V. V.; Radhakrishnan, K.; Abraham, Mathew; Kesavadas, C.; Thomas, Bejoy; Sarma, P. Sankara // Annals of Indian Academy of Neurology;Nov2008 Supplement, Vol. 11, pS160 

    Objective: To investigate the electro-clinical, imaging, pathologic characteristics and post- operative outcome of patients with focal cortical dysplasia (FCD) associated medically refractory epilepsy. Methods: Study cohort comprised all patients with pathologically proven FCD who underwent...

  • Expanding the Geography of Epilepsy: Imaging Evidence for Basal Ganglia Involvement. Theodore, William H. // Epilepsy Currents;Mar/Apr2006, Vol. 6 Issue 2, p40 

    Discusses research being done on the involvement of dopamine in other epileptic syndromes. Reference to a study by V. Bouilleret and colleagues published in a 2005 issue of "Journal of Nuclear Medicine"; Use of a multiple-time graphical analysis and the all-brain statistical parametric mapping...

  • Spatial characterization of interictal high frequency oscillations in epileptic neocortex. Schevon, Catherine A.; Trevelyan, A. J.; Schroeder, C. E.; Goodman, R. R.; McKhann Jr, G.; Emerson, R. G. // Brain: A Journal of Neurology;Nov2009, Vol. 132 Issue 11, p3047 

    Interictal high frequency oscillations (HFOs), in particular those with frequency components in excess of 200 Hz, have been proposed as important biomarkers of epileptic cortex as well as the genesis of seizures. We investigated the spatial extent, classification and distribution of HFOs using a...

  • Anticipating seizures.  // Caribbean Health;Jun2001, Vol. 4 Issue 3, p30 

    The article focuses on the study that provides analysis concerning seizures. Based on clinical observation and conventional monitoring, it is found that epileptic seisures usually occur suddenly and without warning. The reserachers have studied 18 patients with refractory temporal-lobe epilepsy...


Read the Article


Sign out of this library

Other Topics