Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Epilepsy, Absence”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,765 records · Page 98Linked to original sources

Antiabsence seizure activity of specific GABAB and gamma-Hydroxybutyric acid receptor antagonists.

Hydroxybutyric acid (GHB) is a naturally occurring compound that has the ability to induce generalized absence seizures possibly by GABAB-receptor-mediated mechanisms. The object of these experiments was to examine the effectiveness of a range of specific GABAB-receptor agonists and antagonists of varying specificity, as well as the specific GHB-receptor antagonist NCS 382, in two experimental animal models of generalized absence seizures: one in which the seizures are induced by GHB and the other in which the seizures are induced by administration of low-dose (20-mg/kg) pentylenetetrazole. All specific GABAB-receptor antagonists as well as the specific GHB-receptor antagonist produced blockade of experimental absence seizures in both models; pretreatment with GABAB-receptor agonists resulted in generalized absence status epilepticus lasting for hours. These data confirm the concept that specific GABAB-receptor antagonist activity confers antiabsence seizure activity, suggest that the same holds for specific GHB-receptor antagonists, and raise the possibility that both GHB- and GABAB-antagonist drugs have the potential to be useful therapeutic agents in generalized absence seizures.

Animals↗

Animal models of nonconvulsive status epilepticus.

Nonconvulsive status epilepticus includes three clinical situations: complex partial status epilepticus; absence status epilepticus: and obtundation in the presence of electrographic status epilepticus. Animal models that provide information helpful to clinical management exist for both complex partial and absence status epilepticus. In models of complex partial status epilepticus (pilocarpine, kainic acid, and various protocols using electrical stimulation), neuronal damage in discrete neuronal populations follows an episode of status epilepticus. Hippocampal populations are particularly susceptible to neuropathologic sequelae. Although it is difficult in some cases to distinguish whether the inducing agent or the status epilepticus causes neuropathology, the similar patterns of damage caused by different inducing stimuli provide converging lines of evidence suggesting that the neuropathologic consequences stem at least in part from status epilepticus. In models of absence status epilepticus (genetic mutants, pentylenetetrazole), there is relatively scarce neuropathology that can be attributed directly to status epilepticus. Together these data from animal models suggest that neuropathologic consequences from complex partial status epilepticus may be more severe than those from absence status epilepticus. If these findings translate to patients, then nonconvulsive status epilepticus of the complex partial type should be managed more aggressively than nonconvulsive status epilepticus of the absence type.

Animals↗

Involvement of the basal ganglia in refractory epilepsy: an 18F-fluoro-L-DOPA PET study using 2 methods of analysis.

UNLABELLED: Studies in animal models and epileptic patients have led to the suggestion that the basal ganglia (BG) are involved in seizures. PET with 6-18F-L-3,4-fluorodihydroxyphenylalanine (18F-fluoro-L-DOPA) has recently demonstrated a reduction of striatal dopamine uptake in drug-resistant epileptic patients with ring chromosome 20 (r20) using a multiple-time graphical analysis. The aim of the present study was to evaluate the involvement of dopamine in other epileptic syndromes using a multiple-time graphical analysis and the all-brain statistical parametric mapping (SPM) analysis. METHODS: Patients with drug-resistant epilepsy were divided into 3 groups: group 1, with r20 epilepsy (n = 16; mean age +/- SD, 21.5 +/- 5.4 y); group 2, with resistant generalized "absence-like" epilepsy (n = 10; mean age, 32.3 +/- 11.4 y); and group 3, with drug-resistant temporal lobe epilepsy with hippocampal sclerosis (n = 9; mean age, 35.2 +/- 10.3 y). We compared 2 strategies of analysis of the 18F-fluoro-L-DOPA uptake constant (K(i), min(-1)) in BG using a multiple-time graphical analysis using regions of interest (the gold-standard method) and an SPM analysis using a voxel-by-voxel statistical t test to avoid a priori hypotheses in the analysis. Each epileptic group was compared with a group of healthy volunteers (n = 10; mean age, 45.1 +/- 16.5 y). RESULTS: A decrease of the mean K(i) value was observed in the striatum in all groups of patients with both types of analysis. With multiple-time graphical analysis, the reduction was evident using the averaged K(i) values over both hemispheres in each BG. Unilateral decreases in each BG were detected in SPM analysis. A ratio of decrease of 18F-fluoro-L-DOPA uptake was observed in the 3 groups of patients. Only the SPM analysis showed a decrease of 18F-fluoro-L-DOPA uptake ipsilateral to the seizure side in patients with temporal lobe epilepsy. Moreover, the all-brain SPM analysis showed a decrease of 18F-fluoro-L-DOPA uptake in the substantia nigra bilaterally (P < 0.001). CONCLUSION: This result confirms the involvement of dopamine neurotransmission in seizure control related to the type of epileptic syndrome. The difference in epileptic types may depend in part on the seizure frequency.

Adult↗

Topiramate in the treatment of myoclonic-astatic epilepsy in children: a retrospective hospital audit.

BACKGROUND: Myoclonic-Astatic Epilepsy (MAE) usually starts before five years of age and is associated with very frequent seizures and is highly resistant to treatment. AIM: To investigate the outcome of adjunctive topiramate (TPM) therapy in children with a diagnosis of MAE syndrome. SUBJECTS AND METHODS: In an outpatient setting, case notes of 27 children who received TPM were retrieved and analysed. RESULTS: Records of 6 children with MAE, who were experiencing 2-8 atonic seizures daily before starting TPM were studied. Improvement was noted after addition of TPM (mean dose at steady-state 7.4+/-2.5mg/kg/day) to the regimen of 1-3 anti-epileptic drugs they were receiving concurrently. All but one child improved following the titration period: one had 50-80% improvement in the frequency of atonic seizures and three had over 80% improvement. However, one child who showed over 80% improvement and was free of atonic seizures, later developed increased frequency of other seizure types. In one child there was no significant improvement. Improvement has been sustained for over 6 months in three patients and over 4 months in one; three have continued TPM. TPM was stopped in three patients (reduction in seizure control/no improvement). CONCLUSIONS: This study supports the efficacy of TPM in controlling atonic seizures in MAE and indicates that it should be considered as an add-on drug in the management of this 'difficult-to-treat' epileptic syndrome.

Adolescent↗

Evaluation of the "monolog" spike and wave monitor: a study on patients with typical absences.

The aim of this study was to evaluate the effectiveness and accuracy of the "monolog," a pocket-size spike and wave monitor, in patients with typical absence seizures. Two observers were scoring independently and blindly from the monitor the number and duration of the 3 Hz spike-wave discharges from the EEG recordings of 10 selected patients having typical absences. High correlation was found between the two observers' scorings for both the number and the mean duration of events (Spearman's rank correlation (r): 0.9970, P < 0.001, and 0.9758, P < 0.001), as well as between each of them and the "monolog" for the mean event duration (r: 0.9848, P < 0.001, and 0.9788, P < 0.001). Conversely, a poor correlation was found between each of the observers and the "monolog" for the number of events (r: 0.7121, P = 0.021, and 0.6939, P = 0.026). In conclusion, the "monolog" accurately measured the duration of 3 Hz spike-wave activity; however, it failed to accurately count the number of events that occurred throughout the recordings. We suggest that this device, with appropriate modification to its memory epochs, may be a useful tool in monitoring patients with typical absences.

Brain↗