scholarly journals Organization and control of epileptic circuits in temporal lobe epilepsy

2016 ◽  
pp. 127-154 ◽  
Author(s):  
A. Alexander ◽  
M. Maroso ◽  
I. Soltesz
Keyword(s):  
Temporal Lobe Epilepsy ◽  
Temporal Lobe ◽  
And Control

Responses of Deep Entorhinal Cortex are Epileptiform in an Electrogenic Rat Model of Chronic Temporal Lobe Epilepsy

1998 ◽  
Vol 80 (1) ◽  
pp. 230-240 ◽  
Author(s):  
Nathan B. Fountain ◽  
Jonathan Bear ◽  
Edward H. Bertram ◽  
Eric W. Lothman
Keyword(s):  
Temporal Lobe Epilepsy ◽  
Entorhinal Cortex ◽  
Temporal Lobe ◽  
Rat Model ◽  
Action Potentials ◽  
Nmda Antagonist ◽  
Target Cells ◽  
Excitatory Postsynaptic Potential ◽  
Inhibitory Interneurons ◽  
And Control

Fountain, Nathan B., Jonathan Bear, Edward H. Bertram III, and Eric W. Lothman. Responses of deep entorhinal cortex are epileptiform in an electrogenic rat model of chronic temporal lobe epilepsy. J. Neurophysiol. 80: 230–240, 1998. We investigated whether entorhinal cortex (EC) layer IV neurons are hyperexcitable in the post-selfsustaining limbic status epilepticus (post-SSLSE) animal model of temporal lobe epilepsy. We studied naive rats ( n = 44), epileptic rats that had experienced SSLSE resulting in spontaneous seizures ( n = 45), and electrode controls ( n = 7). There were no differences between electrode control and naive groups, which were pooled into a single control group. Intracellular and extracellular recordings were made from deep layers of EC, targeting layer IV, which was activated by stimulation of the superficial layers of EC or the angular bundle. There were no differences between epileptic and control neurons in basic cellular characteristics, and all neurons were quiescent under resting conditions. In control tissue, 77% of evoked intracellular responses consisted of a short-duration [8.6 ± 1.3 (SE) ms] excitatory postsynaptic potential and a single action potential followed by γ-aminobutyric acid-A (GABAA) and GABAB inhibitory post synaptic potentials (IPSPs). Ten percent of controls did not contain IPSPs. In chronically epileptic tissue, evoked intracellular responses demonstrated prolonged depolarizing potentials (256 ± 39 ms), multiple action potentials (13 ± 4), and no IPSPs. Ten percent of epileptic responses were followed by rhythmic “clonic” depolarizations. Epileptic responses exhibited an all-or-none response to progressive increases in stimulus intensity and required less stimulation to elicit action potentials. In both epileptic and control animals, intracellular responses correlated precisely in morphology and duration with extracellular field potentials. Severing the hippocampus from the EC did not alter the responses. Duration of intracellular epileptic responses was reduced 22% by the N-methyl-d-aspartate (NMDA) antagonist d(−)-2-amino-5-phosphonovaleric acid (APV), but they did not return to normal and IPSPs were not restored. Epileptic and control responses were abolished by the non-NMDA antagonist 6,7-dinitroquinoxaline-2-3-dione (DNQX). A monosynaptic IPSP protocol was used to test connectivity of inhibitory interneurons to primary cells by direct activation of interneurons with a stimulating electrode placed near the recording electrode in the presence of APV and DNQX. Using this protocol, IPSPs similar to control ( P > 0.05) were seen in epileptic cells. The findings demonstrate that deep layer EC cells are hyperexcitable or “epileptiform” in this model. Hyperexcitability is not due to interactions with the hippocampus. It is due partially to augmented NMDA-mediated excitation. The lack of IPSPs in epileptic neurons may suggest inhibition is impaired, but we found evidence that inhibitory interneurons are connected to their target cells and are capable of inducing IPSPs.

Preserved monitoring and control processes in temporal lobe epilepsy.

2010 ◽  
Vol 24 (6) ◽  
pp. 775-786 ◽  
Author(s):  
Pilar Andrés ◽  
Giuliana Mazzoni ◽  
Charlotte E. Howard
Keyword(s):  
Temporal Lobe Epilepsy ◽  
Temporal Lobe ◽  
Monitoring And Control ◽  
Control Processes ◽  
And Control

Metamemory in Temporal Lobe Epilepsy: A Study of Sensitivity to Repetition at Encoding

2013 ◽  
Vol 19 (4) ◽  
pp. 453-462 ◽  
Author(s):  
Charlotte E. Howard ◽  
Pilar Andrés ◽  
Giuliana Mazzoni
Keyword(s):  
Temporal Lobe Epilepsy ◽  
Temporal Lobe ◽  
Memory Task ◽  
Unrelated Word ◽  
Monitoring And Control ◽  
Control Processes ◽  
Item Level ◽  
Metamemory Monitoring ◽  
And Control ◽  
Different Levels

AbstractThe purpose of the current study was to determine whether the level of metacognitive sensitivity previously observed in global Judgments-of-Learning (JOLs) in temporal lobe epilepsy (TLE) patients could also be established when making item-by-item JOLs. Fourteen TLE patients and 14 control participants were compared on a memory task where 39 semantically unrelated word pairs were presented at three different levels of repetition. Thirteen word pairs were assigned to each level. A combined JOL and Feeling-of-Knowing (FOK) task was used to examine metamemory monitoring and control processes. The results showed that control participants outperformed TLE patients on recall and recognition. However, both groups were sensitive to repetition of the word pairs throughout the list, revealing intact online monitoring and control processes at encoding. These results are consistent with the findings of Howard et al. (2010) of intact metamemory in TLE patients and extend the findings of Andrés et al. (2010) of metamemory sensitivity from the global level to the item-by-item level. Finally, the current findings provide additional evidence of a dissociation between memory and metamemory in TLE patients. (JINS, 2013, 19, 1–10)

Is impairment in set-shifting specific to frontal-lobe dysfunction? Evidence from patients with frontal-lobe or temporal-lobe epilepsy

2005 ◽  
Vol 11 (4) ◽  
pp. 477-481 ◽  
Author(s):  
CARRIE R. MCDONALD ◽  
DEAN C. DELIS ◽  
MARC A. NORMAN ◽  
EVELYN S. TECOMA ◽  
VICENTE J. IRAGUI-MADOZ
Keyword(s):  
Temporal Lobe Epilepsy ◽  
Frontal Lobe ◽  
Temporal Lobe ◽  
Set Shifting ◽  
Motor Speed ◽  
Control Subjects ◽  
Trail Making ◽  
Patient Groups ◽  
And Control ◽  
Sequencing Task

Frontal-lobe epilepsy (FLE), temporal-lobe epilepsy (TLE), and matched-control subjects were administered the Trail Making Test (TMT) of the Delis-Kaplan Executive Function System (D-KEFS; Delis et al., 2001), which assesses set-shifting on a visuomotor sequencing task. Results indicated that patients with FLE were impaired in both speed and accuracy on the switching condition relative to patients with TLE and controls. The two patient groups did not differ from controls on the four baseline conditions of the test, which assess visual scanning, motor speed, number sequencing, and letter sequencing. In addition, seizure-related variables (i.e., age of seizure onset, duration of epilepsy, and seizure frequency) failed to correlate with set-shifting performance in patients with FLE. These results suggest that patients with FLE can be reliably distinguished from those with TLE and control subjects on set-shifting as measured by the DKEFS TMT. (JINS, 2005,11, 477–481.)

Theory of mind and social competence in children and adolescents with temporal lobe epilepsy.

2019 ◽  
Vol 33 (7) ◽  
pp. 986-995 ◽  
Author(s):  
Elizabeth Stewart ◽  
Cathy Catroppa ◽  
Linda Gonzalez ◽  
Deepak Gill ◽  
Richard Webster ◽  
...  
Keyword(s):  
Theory Of Mind ◽  
Social Competence ◽  
Temporal Lobe Epilepsy ◽  
Children And Adolescents ◽  
Temporal Lobe

Decreased Dopamine D2/D3-Receptor Binding in the Temporal Lobe and the Bilateral Basal Ganglia in patients with Temporal Lobe Epilepsy

2012 ◽  
Vol 43 (01) ◽  
Author(s):  
VE Bernedo Paredes ◽  
H Schwartz ◽  
M Gartenschläger ◽  
M Gartenschläger ◽  
HG Buchholz ◽  
...  
Keyword(s):  
Basal Ganglia ◽  
Temporal Lobe Epilepsy ◽  
Temporal Lobe ◽  
Receptor Binding ◽  
D3 Receptor ◽  
Dopamine D2
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