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Limbic Epilepsy (limbic + epilepsy)

Distribution by Scientific Domains
Medical Sciences100%

Selected Abstracts

Animal Models of Limbic Epilepsies: What Can They Tell Us?

BRAIN PATHOLOGY, Issue 2 2002
Douglas A. Coulter
First page of article [source]

The Midline Thalamus: Alterations and a Potential Role in Limbic Epilepsy

EPILEPSIA, Issue 8 2001
Edward H. Bertram
Summary: ,Purpose: In limbic or mesial temporal lobe epilepsy, much attention has been given to specific regions or cell populations (e.g., the hippocampus or dentate granule cells). Epileptic seizures may involve broader changes in neural circuits, and evidence suggests that subcortical regions may play a role. In this study we examined the midline thalamic regions for involvement in limbic seizures, changes in anatomy and physiology, and the potential role for this region in limbic seizures and epilepsy Methods: Using two rat models for limbic epilepsy (hippocampal kindled and chronic spontaneous limbic epilepsy) we examined the midline thalamus for evidence of involvement in seizure activity, alterations in structure, changes in the basic in vitro physiology of the thalamic neurons. We also explored how this region may influence limbic seizures. Results: The midline thalamus was consistently involved with seizure activity from the onset, and there was significant neuronal loss in the medial dorsal and reuniens/rhomboid nuclei. In addition, thalamic neurons had changes in synaptically mediated and voltage-gated responses. Infusion of lidocaine into the midline thalamus significantly shortened afterdischarge duration. Conclusions: These observations suggest that this thalamic region is part of the neural circuitry of limbic epilepsy and may play a significant role in seizure modulation. Local neuronal changes can enhance the excitability of the thalamolimbic circuits. [source]

Effects of Circadian Regulation and Rest,Activity State on Spontaneous Seizures in a Rat Model of Limbic Epilepsy

EPILEPSIA, Issue 5 2000
Mark Quigg
Summary: Purpose: Circadian regulation via the suprachiasmatic nuclei and rest,activity state may influence expression of limbic seizures. Methods: Male rats (n = 14) were made epileptic by electrical stimulation of the hippocampus, causing limbic status epilepticus and subsequent seizures. We monitored seizures with intrahippocampal electrodes in 12,12-h light/dark (LD) cycles and in continuous dark (DD). We used radiotelemetry monitoring of activity to measure state and body temperature to determine circadian phase. Cosinor analysis and ,2 tests determined whether seizures occurred rhythmically when plotted by phase. State was defined as inactive or active in 10-min epochs based on whether activity count was below or above a cut-off value validated from video observation. Results: In LD, the peak seizure occurrence was 14:59 h after circadian temperature peak (95% confidence limit, 13:37,16:19). Phasic seizure occurrence persisted in DD for 14:05 (12:31,15:38), p < 0.0001, against uniform mean distribution. In LD, 14,787 epochs contained 1,268 seizures; seizures preferentially occurred during inactive epochs (965 observed, 878 expected in proportion to the overall distribution of inactive versus active epochs; p < 0.001). In DD, 20,664 epochs contained 1,609 seizures; seizures had no preferential occurrence by state (999 observed, 1,025 expected; p = 0.16). Conclusions: Limbic seizures occurred with an endogenous circadian rhythm. Seizures preferentially struck during inactivity during entrainment to the light,dark cycle. [source]

The Midline Thalamus: Alterations and a Potential Role in Limbic Epilepsy

EPILEPSIA, Issue 8 2001
Edward H. Bertram
Summary: ,Purpose: In limbic or mesial temporal lobe epilepsy, much attention has been given to specific regions or cell populations (e.g., the hippocampus or dentate granule cells). Epileptic seizures may involve broader changes in neural circuits, and evidence suggests that subcortical regions may play a role. In this study we examined the midline thalamic regions for involvement in limbic seizures, changes in anatomy and physiology, and the potential role for this region in limbic seizures and epilepsy Methods: Using two rat models for limbic epilepsy (hippocampal kindled and chronic spontaneous limbic epilepsy) we examined the midline thalamus for evidence of involvement in seizure activity, alterations in structure, changes in the basic in vitro physiology of the thalamic neurons. We also explored how this region may influence limbic seizures. Results: The midline thalamus was consistently involved with seizure activity from the onset, and there was significant neuronal loss in the medial dorsal and reuniens/rhomboid nuclei. In addition, thalamic neurons had changes in synaptically mediated and voltage-gated responses. Infusion of lidocaine into the midline thalamus significantly shortened afterdischarge duration. Conclusions: These observations suggest that this thalamic region is part of the neural circuitry of limbic epilepsy and may play a significant role in seizure modulation. Local neuronal changes can enhance the excitability of the thalamolimbic circuits. [source]