Home About us Contact
|
Home About us Contact | ||
|
|
||
Seizure Pattern (seizure + pattern)
Selected AbstractsAn infantile-onset, severe, yet sporadic seizure pattern is common in Sturge-Weber syndromeEPILEPSIA, Issue 9 2009Eric H. Kossoff Summary The young age of onset and frequently intractable nature of seizures associated with Sturge-Weber syndrome (SWS) have been well-reported in large studies. However, many clinicians also anecdotally describe prolonged but sporadic seizure clusters. Over a 5-year period, 77 children and adults with SWS and at least one reported seizure were referred to and evaluated at the Hunter Nelson Sturge-Weber Center at the Kennedy Krieger Institute. The median age of seizure onset was 6 months with 43 (56%) presenting <1 year of age. Age at seizure onset ,6 months was associated with increased hemiparesis, but not seizures. A characteristic pattern of clustering, intense seizures followed by prolonged seizure-free periods was reported in 30 (39%), but was not associated with worse prognosis. This seizure pattern appears to be common with SWS and leads to difficult treatment decisions, especially in regard to the timing of potential surgical resection. [source] Audiogenic kindling in Wistar and WAG/Rij rats: Kindling-prone and kindling-resistant subpopulationsEPILEPSIA, Issue 10 2008Lyudmila V. Vinogradova Summary Purpose:, Audiogenic kindling (AK) is a model of naturally occurring epileptogenesis triggered by repeated sound stimulation of rats genetically prone to audiogenic seizures. It is accepted that limbic seizure networks underlie progressive changes in behavioral seizure pattern during AK. The present study investigated AK progression in rats susceptible and unsusceptible to absence seizures. Methods:, Progression of AK as indicated by an appearance and intensification of limbic clonus was examined in Wistar Albino Glaxo/Rijswijk (WAG/Rij) rats with genetic absence epilepsy and in Wistar rats. Results:, Subpopulations of kindling-prone and kindling-resistant rats were found in both Wistar and WAG/Rij strains. Despite identical seizure responses to the first sound stimulation, AK progression dramatically differed between the two subpopulations. AK-prone rats exhibited rapid kindling development up to maximal stage-5 severity. In AK-resistant rats, limbic clonus did not appear after 30 stimulations or if it appeared, it did not progress beyond stage 2. The proportions of AK-prone and AK-resistant animals within Wistar and WAG/Rij strains were similar. Comparison of Wistar and WAG/Rij rats within the kindling-prone and kindling-resistant groups did not reveal a significant strain effect on AK progression. However, within the WAG/Rij strain, a significantly higher incidence of absence seizures was found in AK-resistant rats compared to AK-prone rats. Conclusions:, The present study demonstrates that sensitivity to sound-induced epileptogenesis differs dramatically within Wistar and WAG/Rij strains, whereas genetic susceptibility to absence seizures does not change AK progression significantly. It is supposed that an increased incidence of nonconvulsive seizures and resistance to kindling result from a common seizure modulating mechanism. [source] A Large-scale Mutagenesis Screen to Identify Seizure-resistant ZebrafishEPILEPSIA, Issue 6 2007Scott C. Baraban Summary:,Methods: Seizures were induced with pentylenetetrazole (PTZ). Zebrafish were analyzed between 3 and 7 days postfertilization (dpf). Genome mutations were induced in founders by using N- ethyl-nitrosourea (ENU). Seizure behavior was monitored by using a high-speed camera and quantified by locomotion-tracking software. Electrographic activity was monitored by using a field-recording electrode placed in the optic tectum of agar-immobilized zebrafish. Results: Short-term PTZ exposure elicited a burst-suppression seizure pattern in 3-dpf zebrafish and more complex activity consisting of interictal- and ictal-like discharges at 7 dpf. Prolonged exposure to PTZ induced status epilepticus,like seizure activity and fatality in wild-type zebrafish larvae. With a PTZ survival assay at 6,7 dpf, we identified six zebrafish mutants in a forward-genetic screen covering nearly 2,000 F2 families. One mutant (s334) also was shown to exhibit reduced behavioral activity on short-term PTZ exposure and an inability to generate long-duration ictal-like discharge. Conclusions: Zebrafish offers a powerful tool for the identification and study of a genetic basis for seizure resistance. [source] Seizure Suppression by Adenosine A1 Receptor Activation in a Mouse Model of Pharmacoresistant EpilepsyEPILEPSIA, Issue 7 2003Nicolette Gouder Summary: Purpose: Because of the high incidence of pharmacoresistance in the treatment of epilepsy (20,30%), alternative treatment strategies are needed. Recently a proof-of-principle for a new therapeutic approach was established by the intraventricular delivery of adenosine released from implants of engineered cells. Adenosine-releasing implants were found to be effective in seizure suppression in a rat model of temporal lobe epilepsy. In the present study, activation of the adenosine system was applied as a possible treatment for pharmacoresistant epilepsy. Methods: A mouse model for drug-resistant mesial temporal lobe epilepsy was used, in which recurrent spontaneous seizure activity was induced by a single intrahippocampal injection of kainic acid (KA; 200 ng in 50 nl). Results: After injection of the selective adenosine A1 -receptor agonist, 2-chloro- N6 -cyclopentyladenosine (CCPA; either 1.5 or 3 mg/kg, i.p.), epileptic discharges determined in EEG recordings were completely suppressed for a period of ,3.5 h after the injections. Seizure suppression was maintained when 8-sulfophenyltheophylline (8-SPT), a non,brain-permeable adenosine-receptor antagonist, was coinjected systemically with CCPA. In contrast, systemic injection of carbamazepine or vehicle alone did not alter the seizure pattern. Conclusions: This study demonstrates that activation of central adenosine A1 receptors leads to the suppression of seizure activity in a mouse model of drug-resistant epilepsy. We conclude that the local delivery of adenosine into the brain is likely to be effective in the control of intractable seizures. [source] Resistance to Propagation of Amygdaloid Kindling Seizures in Rats with Genetic Absence EpilepsyEPILEPSIA, Issue 10 2002Esat E, kazan Summary: ,Purpose: The existence of absence epilepsy and temporal partial seizure pattern in the same patient is an uncommon state. In the present study, we aimed to evaluate whether the process of kindling as a model of complex partial seizures with secondary generalization is altered in rats with genetic absence epilepsy. Methods: Six- to 12-month-old nonepileptic control Wistar rats and genetic absence epileptic rats from Strasbourg (GAERS) were used in the experiments. One week before the experiments, bilateral stimulation and recording electrodes were implanted stereotaxically into the basolateral amygdala and cortex, respectively. Animals were stimulated at their afterdischarge threshold current twice daily for the process of kindling and accepted as fully kindled after the occurrence of five grade 5 seizures. Bilateral EEGs from amygdala and cortex were recorded continuously during 20 min before and 40 min after each stimulus. Results: All control Wistar rats were fully kindled after stimulus 12 to 15. Although the maximal number of stimulations had been applied, GAERS remained at stage 2, and no motor seizures were observed. The afterdischarge duration in bilateral amygdala and the cortex after the kindling stimulus was shorter in GAERS when compared with control rats. Conclusions: Occurrence of only grade 2 seizures and no observation of grade 3,5 seizures in GAERS with the maximal number of stimulations would suggest that the generalized absence seizures may be the reason of the resistance in the secondary generalization of limbic seizures during amygdala kindling. [source] Prognostic Implication of Contralateral Secondary Electrographic Seizures in Temporal Lobe EpilepsyEPILEPSIA, Issue 11 2000Ki Hyeong Lee Summary: Purpose: Interhemispheric propagation of seizures in temporal lobe epilepsy is frequently noted during intracranial EEG monitoring. We hypothesized that a distinct secondary electrographic seizure (DSES) in the temporal lobe contralateral to primary seizure onset may be an unfavorable prognostic indicator. Methods: We reviewed intracranial depth electrode EEG recordings, 1-year outcome, and medical records of 51 patients (M 29, F 22: age 15,64 years) who underwent anterior temporal lobectomy during 1988,96. We defined DSES as a seizure that spread to the contralateral temporal lobe and produced distinct contralateral EEG features. The distinct feature was focal involvement of one or two electrode contacts at onset, which starts and evolves independently from the ipsilateral temporal lobe. We considered DSES as the predominant seizure pattern when it occurred in more than one half of the patients' recorded seizures. Results: Only nine of 19 (47%) patients with predominant DSES had a 1-year seizure-free outcome, whereas 27 of 32 (84%) patients without predominant DSES had a 1-year seizure-free outcome (p <0.01). Bitemporal independent seizures were more common in patients with predominant DSES (9/19 versus 0/32; p <0.001). Conclusion: Our results suggest that distinct contralateral secondary electrographic seizure is a predictor of unfavorable outcome and is also more likely to be associated with bitemporal seizures. [source] The Impact of Cerebral Source Area and Synchrony on Recording Scalp Electroencephalography Ictal PatternsEPILEPSIA, Issue 11 2007James X. Tao Summary Purpose: To determine the cerebral electroencephalography (EEG) substrates of scalp EEG seizure patterns, such as source area and synchrony, and in so doing assess the limitations of scalp seizure recording in the localization of seizure onset zones in patients with temporal lobe epilepsy. Methods: We recorded simultaneously 26 channels of scalp EEG with subtemporal supplementary electrodes and 46,98 channels of intracranial EEG in presurgical candidates with temporal lobe epilepsy. We correlated intracranial EEG source area and synchrony at seizure onset with the corresponding scalp EEG. Eighty-six simultaneous intracranial- and scalp-recorded seizures from 23 patients were evaluated. Results: Thirty-four intracranial ictal discharges (40%) from 9 patients (39%) had sufficient cortical source area (namely > 10 cm2) and synchrony at seizure onset to produce a simultaneous or nearly simultaneous focal scalp EEG ictal pattern. Forty-one intracranial ictal discharges (48%) from 10 patients (43%) gradually achieved the necessary source area and synchrony over several seconds to generate a scalp EEG ictal pattern. These scalp rhythms were lateralized, but not localizable as to seizure origin. Eleven intracranial ictal discharges (13%) from 4 patients (17%) recruited the necessary source area, but lacked sufficient synchrony to result in a clearly localized or lateralized scalp ictal pattern. Conclusions: Sufficient source area and synchrony are mandatory cerebral EEG requirements for generating scalp-recordable ictal EEG patterns. The dynamic interaction of cortical source area and synchrony at the onset and during a seizure is a primary reason for heterogeneous scalp ictal EEG patterns. [source] Intraoperative hyperventilation vs remifentanil during electrocorticography for epilepsy surgery , a case reportACTA NEUROLOGICA SCANDINAVICA, Issue 6 2010T. W. Kjaer Kjaer TW, Madsen FF, Moltke FB, Uldall P, Hogenhaven H. Intraoperative hyperventilation vs remifentanil during electrocorticography for epilepsy surgery , a case report Acta Neurol Scand: 2010: 121: 413,417. © 2010 The Authors Journal compilation © 2010 Blackwell Munksgaard. Background,,, Traditionally, intraoperative intracranial electroen-cephalography-recordings are limited to the detection of the irritative zone defined by interictal spikes. However, seizure patterns revealing the seizure onset zone are thought to give better localizing information, but are impractical due to the waiting time for spontaneous seizures. Therefore, provocation by seizure precipitants may be used with the precaution that spontaneous and provoked seizures may not be identical. Objective,,, We present evidence that hyperventilation induced and drug induced focal seizures may arise from different brain regions in the same patient. Methods,,, Hyperventilation and ultra short acting opioid remifentanil were used separately as intraoperative precipitatants of seizure patterns, while recording from subdural and intraventricular electrodes in a patient with temporal lobe epilepsy. Two different ictal onset zones appeared in response to hyperventilation and remifentanil. Both zones were resected and the patient has remained essentially seizure free for 1 year. Furthermore, this is the first description of hyperventilation used as an intraoperative seizure precipitant in human focal epilepsy. [source] | ||||||||||