Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0036572 (seizures)
 80,221 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The role of the inter-ictal EEG in predicting seizure relapse after antiepileptic drug withdrawal (AED-W) is unclear. A prospective study on AED-W is in progress. This trial includes routine and sleep EEG recordings every 3 and 6 months, respectively, at each step of the drug discontinuation and periodically during follow-up. Data obtained for 136 patients (mean age 23.2 years; 63 with Idiopathic Generalized Epilepsy IGE, 73 with Partial Cryptogenic or Symptomatic Epilepsy PE; without associated neuropsychiatric handicap; with at least 1 year of follow-up after AED-W) were analysed. EEG recordings from seizure onset were available for all patients. Data were analysed separately in IGE and PE patients. The presence of inter-ictal epileptiform abnormalities (IEAs) at the seizure onset and just before AED-W does not seem to predict the AED-W outcome. However, results indicate an association between persisting and increased IEAs during AED-W and a higher relapse rate in both groups, which was statistically significant in the IGE patients.
Seizure 1993 Sep
PMID:Drug withdrawal in patients with epilepsy: prognostic value of the EEG. 816 85

Sleep deprivation (SD) is a method widely used to activate EEG epilept oform activity, but the basis of this effect remains unknown. One possibilty is that SD shares a common mechanism with physical and psychological stresses that also precipitate seizures. Because endogenous opioids are released during stress, opioids may play a role in enhancing epileptiform EEG patterns after SD. We report the effects of SD on EEG epileptiform activity in a small but highly homogeneous population of 13 epileptic patients with idiopathic (primary) generalized epilepsy (IGE). SD increased EEG interictal epileptiform discharges (IEDs); this activation was not modified by naloxone (NAL). Our results, in contrast to those of previous investigations of localization-related epilepsy, which showed an increase in IEDs after NAL administration, suggest a possible difference in the mechanism whereby SD enhances IEDs in IGE and localization-related epilepsy.
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PMID:Failure of naloxone to modify electroencephalogram interictal epileptiform discharges in patients with primary generalized epilepsy after slation. 860 25

Impaired reproductive function is thought to frequently affect women with epilepsy, mainly when seizures originate in the temporal lobe. In this study, we evaluated menstrual cycle features and assessed ovulation by determining luteal progesterone (Pg) levels in 101 consecutive women with epilepsy (36 with idiopathic generalized epilepsy -IGE; 65 with partial epilepsy -PE), aged between 16 and 50 years, treated with various antiepileptic drugs (AED). PE originated in the temporal lobe (TLE) in 40 subjects, in the frontal lobe in 13, in the parietal lobe in 2, while the origin of focal seizures remained undetermined in 10 patients. In all patients, menstrual and reproductive history, body mass index, hair distribution and hormonal pattern were assessed. Suprapubic ovary ultrasound (US) examination was carried out in 83 patients (28 with IGE, 55 with PE). Three patients with IGE and one with PE were amenorrheic. Oligomenorrhea occurred in 16 patients, polymenorrhea in 2. Changes in menstrual cyclicity were independent from epilepsy type (19.4% in IGE; 23.1% in PE) and from origin of focal discharges (22.5% of patients with TLE; 20.0% with origin in other brain areas). Luteal Pg levels remained below 2 ng/ml in 30 patients independently of epilepsy type. Corpus luteum dysfunction was combined with hyperandrogenism in 15 of these patients. In the other cases different alterations of hypothalamus-pituitary-ovary axis were observed. Valproic acid blunted luteal Pg surge more frequently than other AED. Polycystic ovaries (PCO) were observed in 14 (16.9%) patients (21.0% with IGE: 14.5% with PE). These prevalences are not higher than those reported in the general population. Among PE patients, PCO was found in 1 case with undetermined focal origin and in 7 TLE cases, who also had ovary volume significantly larger than patients with seizures originating from the frontal or parietal lobe. Epileptic women exhibited an increased occurrence of multifollicular ovaries (MFO) found in 12 cases (14.4% vs 5% in the general population). However, no defined hormonal or clinical pictures were associated with this US alteration in most patients. These findings reappraise the impact of ovary alterations in women mainly affected by mild to moderate epilepsy, on differing AED regimens, with the exception of more frequent ovulatory dysfunction and PCO occurrence in patients taking VPA.
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PMID:Menstrual cycle and ovary alterations in women with epilepsy on antiepileptic therapy. 941 5

Idiopathic generalized epilepsy is one of the most common forms of epilepsy. The aetiology of IGE is genetically determined, but the pattern of inheritance is still undefined. Recent studies in common IGE showed evidence for linkage on chromosome 18q12 at the D18S474 locus. The aim of our study was to compare the distribution of allelic variants of D18S474 locus in children affected by generalized tonic-clonic seizures and in healthy controls. We studied 295 children: 121 cases and 174 controls. We found that the D18S474(8) allele was significantly more frequent and D18S474(9) significantly less frequent in cases compared with controls (p<.001). In conclusions, our findings show the association between the D18S474 marker and IGE in which early onset GTCS represent the most prevalent seizure type.
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PMID:Association between D18S474 locus on chromosome 18q12 and idiopathic generalized epilepsy. 1679 Mar 32

The main categories of nonconvulsive status epilepticus are: complex partial and absence status. Absence status was reported to occur de novo in later life as a situation-related, single event. We report four cases of absence status with presentation after the age of 60 years. At admission, no history of epilepsy had been mentioned. The preliminary diagnosis of absence status occurring de novo in later life had to be changed on completion of case histories. All patients had suffered from idiopathic generalized epilepsy with absence seizures, which had resolved after puberty. A second peak of IGE, with repeated episodes of absence status after the menopause and without identifiable triggering factors is assumed.
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PMID:Absence status in the elderly as a late complication of idiopathic generalized epilepsies. 1730 10

Intracortical disinhibitory mechanisms play a crucial role in epilepsy. Therefore, the recruitment of motor cortical excitability was evaluated to distinct between focal and generalized epileptic syndromes. Twenty-five untreated patients with epilepsy and 20 controls were enrolled. Classification into focal (FE, n=10) or idiopathic generalized (IGE, n=15) epilepsy was based on seizure semiology, EEG and MRI. The recruitment of motor cortical inhibition and facilitation was measured by varying the stimulus intensity (SI) of the first conditioning stimulus in a paired-pulse transcranial magnetic stimulation (TMS) paradigm producing stimulus-response (S-R) curves of intracortical excitability. S-R curves were then compared with other commonly used TMS measures of cortical excitability [cortical silent period (CSP) and motor threshold (MT)]. In patients with IGE, inhibition occurred only at higher conditioning SIs compared to patients with focal epilepsy and controls. Recruitment of inhibition was unchanged in patients with focal epilepsy compared to controls. Recruitment of facilitation (ICF), CSP duration and MT, were not different between patients with FE or IGE or between patients and controls. These results suggest that the recruitment for motor cortical inhibition in patients with IGE is less effective. This may reflect a disturbed access to or an increased threshold of inhibitory neurons within the motor cortex. Impaired recruitment of inhibition might be a helpful parameter to access cortical excitability in newly diagnosed patients with generalized or focal epilepsy.
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PMID:Recruitment of motor cortex inhibition differentiates between generalized and focal epilepsy. 1928 51

Anion exchanger 3 (AE3), expressed in the brain, heart, and retina, extrudes intracellular HCO(3)(-) in exchange for extracellular Cl(-). The SLC4A3 gene encodes two variants of AE3, brain or full-length AE3 (AE3(fl)) and cardiac AE3 (cAE3). Epilepsy is a heterogeneous group of disorders characterized by recurrent unprovoked seizures that affect about 50 million people worldwide. The AE3-A867D allele in humans has been associated with the development of IGE (IGE), which accounts for approximately 30% of all epilepsies. To examine the molecular basis for the association of the A867D allele with IGE, we characterized wild-type (WT) and AE3(fl)-A867D in transfected human embryonic kidney (HEK)-293 cells. AE3(fl)-A867D had significantly reduced transport activity relative to WT (54 +/- 4%, P < 0.01). Differences in expression levels or the degree of protein trafficking to the plasma membrane did not account for the defect of AE3(fl)-A867D. Treatment with 8-bromo-cAMP (8-Br-cAMP) increased Cl(-)/HCO(3)(-) exchange activity of WT and AE3(fl)-A867D to a similar degree, which was abolished by preincubation with the protein kinase A (PKA)-specific inhibitor H89. This indicates that PKA regulates WT and AE3(fl)-A867D Cl(-)/HCO(3)(-) exchange activity. No difference in Cl(-)/HCO(3)(-) exchange activity was found between cultures of mixed populations of neonatal hippocampal cells from WT and slc4a3(-/-) mice. We conclude that the A867D allele is a functional (catalytic) mutant of AE3 and that the decreased activity of AE3(fl)-A867D may cause changes in cell volume and abnormal intracellular pH. In the brain, these alterations may promote neuron hyperexcitability and the generation of seizures.
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PMID:Characterization of an epilepsy-associated variant of the human Cl-/HCO3(-) exchanger AE3. 1960 33

The aim of this work is to show explicitly why the "idiopathic generalized epilepsy" concept becomes outfashioned and untenable. As the concept of "generalized epilepsies" is from long ago closely related to the thalamo-cortical system, we briefly summarize the functional anatomy, the double working mode of the thalamo-cortical system in different vigilance states and it's role in development of the spike-wave pattern. The next part shows weaknesses of this concept from the EEG, seizure semiology, and neuroimaging point of view. Further experimental and clinical arguments are accumulated from the reflex epileptic features in IGE, indicating local/regional cortical hyperexcitability. A separate part is devoted to genetic aspects of the question. Lastly implications to epilepsy classification are shown and an outlook toward a unified epilepsy concept is provided. The epileptic disorder of the thalamo-cortical system is responsible for the development of "generalized", synchronous spike-wave paroxysms as the common neurophysiological background in "primary" - idiopathic and in "secondary" generalized epilepsies. This disorder is specifically related to the burstfiring working mode of the thalamo-cortical system during NREM sleep (is an epileptic exageration of it). The "generalized" epilepsy category should be abandoned, being misleading. Epilepsies are proposed to be classified according to their network properties and relations to different physiological systems of the brain. The different phenotypes, named earlier idiopathic (primary) generalized, or symptomatic (secondary) generalized (with encephalopathic features), should be delineated depending on the following factors: 1. speed and extent of syncronization within the thalamo-cortical system, 2. the way how the thalamo-cortical system is involved, 3. which kind of cortical triggers play role, 4. the degree and level of the disorder (restricted to the molecular level or extended to the level of structural alterations - in the cortex or more diffusely, 5. genetic targets and features.
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PMID:New vistas and views in the concept of generalized epilepsies. 2002 27

Children with idiopathic generalized epilepsy with only generalized tonic-clonic seizures (IGE-GTC) were selected from the Nova Scotia Childhood Epilepsy population-based cohort. All were neurologically and intellectually normal with generalized spike-wave on EEG. Of the epilepsy cohort of 692, 40(5.8%) had IGE-GTC. Follow-up averaged 22.2+/-7.6 years. Twenty-seven (75%) had a complete terminal remission (seizure-free, off medication) for 16.1+/-8.6 years. There were no deaths or intractable seizures. For those >21 years of age at follow up (N=30), major adverse social outcomes were psychiatric diagnosis 8 (27%), no high school graduation 12 (40%), pregnancy outside a stable relationship 11 (38%), living alone 7 (23%), unemployment 10 (33%) and criminal conviction 2 (7%). Satisfaction with their lives, friendships and social activities were reported by 55-65%. IGE-GTC is a recognizable, relatively benign epilepsy syndrome with complete remission in 75%. Learning problems and unsatisfactory social outcome are unfortunately common.
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PMID:Idiopathic generalized epilepsy with generalized tonic-clonic seizures (IGE-GTC): a population-based cohort with >20 year follow up for medical and social outcome. 2047 24

Temporal lobe epilepsy (TLE) has been associated with the phenomenon of accelerated long-term forgetting (ALF), in which memories are retained normally over short delays but are then lost at an accelerated rate over days or weeks. The causes of ALF, and whether it represents a consolidation deficit distinct from the one associated with forgetting over short delays, remain unclear. In addition, methodological issues have made results of some previous studies difficult to interpret. This study used improved methodology to investigate the role of seizure activity in ALF. Forgetting was assessed in participants with TLE (who have involvement of temporal lobe structures) and idiopathic generalised epilepsy (IGE; in which seizures occur in the absence of identified structural pathology in the temporal lobes). Learning of novel stimuli was matched between patients with TLE, patients with IGE and healthy controls matched for age and IQ. Results indicated that the TLE group showed accelerated forgetting between 30-min and three-weeks, but not between 40-s and 30-min. In contrast, rates of forgetting did not differ between patients with IGE and controls. We conclude that (1) ALF can be demonstrated in TLE in the absence of methodological confounds; (2) ALF is unlikely to be related to the experience of epilepsy that does not involve the temporal lobes; (3) neither seizures during the three-week delay nor polytherapy was associated with ALF.
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PMID:Accelerated long-term forgetting in temporal lobe but not idiopathic generalised epilepsy. 2154 34


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