PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Epilepsy, Generalized”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 379 records · Page 21Linked to original sources

Brainstem triggers absence seizures in human generalized epilepsy.

Simultaneous analysis of brainstem auditory evoked potentials (BAEPs) with reference to electroencephalography (EEG) was designed to examine the brainstem function corresponding to the EEG event. With this method, we investigated the brainstem function pre- and during the paroxysmal discharge in human absence seizures classified as primary generalized epilepsy (PGE). Two types of functional change in the lower brainstem were revealed as parameters of wave-III components (amplitude and area) of BAEPs without significant change in the upper brainstem. One was long-range biphasic fluctuation (acceleration followed by abrupt deceleration with the maximum -6.4+/-3.2 s before the seizure onset), and the other was rhythmic oscillation with 3 Hz. The latter, synchronized with the cortical spike-and-wave complex, imposed on the descending slope of the former. One important point is that both preceded the onset of cortical paroxysmal discharge. The results reappraise the classical hypothesis of "centrencephalic system" on seizure generating mechanism in human PGE. The results prove the primary triggering role of the lower brainstem that is independent of sleep-related synchronizations. The method is applicable to other types of EEG event for the investigation of brainstem involvement.

Adolescent↗

Generalized epilepsy in a patient with hypokalemic periodic paralysis and cardiac arrhythmia.

A 17-year-old female who had Hypokalemic periodic paralysis with arrhythmia developed syncopal attacks. Although syncope in this rare disorder has been attributed to ventricular tachycardia or ventricular fibrillation, the clinical manifestation, electroencephalogram, serum electrolytes and blood sugar at the attack, and the results of lumbar puncture indicated that idiopathic generalized epilepsy was the cause of the syncopal attacks in the present case. To our knowledge, this is the first case report of the association of epilepsy with periodic paralysis and arrhythmia in the literature.

Adolescent↗

Benign familial neonatal convulsions: generalized epilepsy?

A 3-year-old girl is presented with benign familial neonatal convulsions. She had seizures during the neonatal period and at age 3 months. Seizure manifestations and ictal electroencephalography indicated that she had not experienced generalized seizures but partial seizures, although international classifications of epilepsy define benign familial neonatal convulsions as generalized epilepsy.

Child, Preschool↗

Lamotrigine in absence and primary generalized epilepsies.

Although lamotrigine has been approved in the United States as adjunctive therapy for partial seizures in patients older than 12 years, there is increasing evidence that it is just as effective, if not more effective, in the treatment of generalized seizures. A large number of open-label studies and some single-blind data, all using lamotrigine as add-on therapy in patients with previously refractory generalized seizures, are available. Controlled studies, some on newly diagnosed, previously untreated patients with generalized seizures are ongoing. Investigations have demonstrated that patients with the following generalized seizure types improve with lamotrigine add-on therapy: Typical and atypical absence, atonic, generalized tonic-clonic, myoclonic, and clonic seizures. Response rates, defined as the percentage of patients with better than 50% reduction in seizure frequency, have been, depending on seizure type, in the range of 30% to 56%, with 0 to 33% of the patients becoming seizure free. The best responses have been noted in typical and atypical absences, and atonic seizures. Children and adults appear to have comparable responses. In addition, add-on studies in patients with specific, previously refractory, epilepsy syndromes have demonstrated that the best improvement in seizure control occurs in patients with petit mal epilepsy, "other symptomatic" generalized epilepsies, and in Lennox-Gastaut syndrome, followed by patients with other myoclonic epilepsies, myoclonic absence and West syndrome. Many previously refractory patients are able to achieve lamotrigine monotherapy. However, patients with nonprogressive myoclonic epilepsy have little, if any, response. Early data from ambulatory encephalographic (EEG) recordings in patients with previously refractory absence seizures, and from controlled studies on patients with newly diagnosed typical absence seizures, appear to confirm the efficacy of lamotrigine in those patients. Controlled studies are ongoing in patients with absence seizures, in patients with generalized tonic-clonic seizures, and in patients with Lennox-Gastaut syndrome. Dosing in generalized seizures is similar to that for partial seizures. Because of the shorter half-life of lamotrigine in children, as compared to adults, higher (mg/kg) doses are often needed in young patients. We conclude that lamotrigine is a promising drug for absence and primary generalized seizures in both children and adults.

Adolescent↗

Association analysis between a regulatory-promoter polymorphism of the human monoamine oxidase A gene and idiopathic generalized epilepsy.

Monoaminergic neurotransmission plays an important role in the regulation of neuronal network excitability and seizure activity. Therapeutic inhibition of the mitochondrial enzyme monoamine oxidase A (MAO-A), which is involved in the degradation and inactivation of monoaminergic neurotransmitters, has been shown to confer a potent anticonvulsant effect. These and other findings suggest a possible role of the X-linked MAO-A gene in epileptogenesis. Therefore, our study was designed to test for an association between a novel MAO-A gene promoter polymorphism and common subtypes of idiopathic generalized epilepsy (IGE). The length of a 30-bp repetitive sequence approximately 1.2 kb upstream of the ATG initiation codon was assessed in 126 patients with juvenile myoclonic epilepsy (JME), 122 patients with idiopathic absence epilepsy (IAE), and 248 healthy controls of German descent. Both sexes were analyzed separately. Although we observed a trend towards a lower number of heterozygotes carrying the 3 and 4 copy alleles in female IAE patients (chi2 = 3.813, df = 1, P = 0.053), allele frequencies did not deviate significantly between patients and controls. Thus, our results do not provide evidence for a contribution of the functional MAO-A gene promoter polymorphism to the pathogenesis of common IGE subtypes.

Adult↗

Selective amplitude histograms: a statistical approach to EEG-single unit relationships in generalized epilepsy.

Statistical analysis techniques that permit detection and quantification of EEG-single unit correlations were employed in a study of generalized penicillin epilepsy in the cat. Single unit activity was recorded in cerebral and cerebellar cortices and compared to the locally recorded EEG. It was found that during generalized paroxysmal activity the background EEG was significantly related to the time of occurrence of unit discharge. The degree of synchrony of various units differed but tended to increase as the duration and extent of paroxysmal activity increased. These relationships were usually not evident upon visual inspection of the original unprocessed data but were consistently detected by the analysis techniques described here. The results demonstrate the usefulness of a statistical approach to the analysis of single unit data and suggest that, not only is there a significant relationship between paroxysmal events and neuronal activity in generalized penicillin epilepsy, but also an overall trend to closer synchronization of EEG and single unit discharges during nonparoxysmal periods.

Action Potentials↗

Benign myoclonic epilepsy of infancy: electroclinical symptomatology and differential diagnosis from the other types of generalized epilepsy of infancy.

Benign myoclonic epilepsy in infancy (BME) is characterized by the occurrence of brief myoclonic attacks in normal infants aged 4 months to 3 years. There is no prior personal history, although in some patients 1 or 2 isolated febrile convulsions may occur prior to the onset of myoclonias. A family history of epilepsy or febrile convulsions is present in 30% of cases. Myoclonic attacks are short and mild, they involve mainly the head and upper limbs. The psychomotor development continues normally after the onset of seizures. The EEG shows a normal background activity and generalized spike-wave or polyspike-wave discharges associated with the myoclonias. These abnormalities are activated by drowsiness and during the first stages of sleep. A clinical and EEG photosensitivity is present in one-third of the patients. Myoclonias can be easily controlled by valproate monotherapy. Rare grand mal seizures can occur during adolescence, after withdrawal of drug treatment. The psychomotor evolution is good if treatment is started early. When myoclonias begin during the first year of life, the diagnoses of cryptogenic infantile spasms and of non-epileptic benign infantile myoclonus must be eliminated. In cases with a later onset, the following diagnoses can usually be easily discarded: cryptogenic Lennox-Gastaut syndrome, myoclonic-astatic epilepsy and unclassified epilepsies with the association of myoclonias and other types of seizures.

Cerebral Cortex↗

Generalized epilepsies: emerging insights into cellular and genetic mechanisms.

In the past year we have gained significant insights into the molecular and genetic mechanisms underlying generalized absence seizures, primarily through the study of animal models. Also a new understanding has emerged about the genetic bases of certain syndromes in which generalized myoclonic and tonic-clonic seizures are expressed. New insights into these different types of generalized seizures may lead eventually to new therapies.

Animals↗

[Differential diagnosis in idiopathic generalized epilepsies with tonic-clonic seizures: assessment of the use of ambulatory EEG and video/EEG monitoring].

The value of long-term cassette EEG (24-EEG) and Video/EEG for differential diagnosis and classification of idiopathic epilepsies with generalised tonic-clonic seizures (GTCS) was evaluated in twenty-eight patients. The analysis of clinical and EEG features allowed proper classification of epileptic syndrome in twenty-two (79%) patients. In twelve cases absences or myoclonic seizures appeared beside GTCS after 1-9 years from epilepsy onset (mean 3.3 yrs). EEG and clinical data allowed to classify epilepsy in nine (75%) of those patients: in six patients as juvenile absence epilepsy and in three as juvenile myoclonic epilepsy. Sixteen patients suffered from GTCS only (mean duration of epilepsy 10.6 years); in thirteen of them (81%) the diagnosis of epilepsy with GTCS on awakening (AGM) could be established. 24-EEG and Video/EEG helped to demonstrate (a) interictal generalized spike/polyspike-wave discharges (SW/PSW) 3-6 Hz not present in routine EEG in 25% of patients, (b) typical circadian distribution of discharges in AGM patients and (c) absences and myoclonic seizures in 32% of patients. Slow spike-wave variants and focal changes in EEG which could suggest secondarily generalized GTCS were the main diagnostic problem.

Adolescent↗

Primary generalized epilepsy: a risk factor for seizures in labor and delivery?

PURPOSE: Women in the United States who have epilepsy give birth to about 20000 newborns every year. Because seizures during late gestation and delivery may seriously affect the fetus, and because primary generalized tonic-clonic (GTC) seizures may occur during labor and delivery in 1-2% of women with epilepsy, we attempted to define the rate, risks, and causes of seizures during labor and delivery. METHODS: To characterize seizures during labor and delivery, we retrospectively analyzed 89 consecutive pregnancies of women with epilepsy on antiepileptic drugs (AEDs). Six epileptologists in our group had treated these patients. We confirmed data and acquired new information by telephone for 83.1% of the pregnancies, and categorized the women as having primary generalized or partial epilepsy. Most of the patients (78%) were on monotherapy during pregnancy; 20% took two AEDs, and 3% took three AEDs during that period. RESULTS: Seizures during labor and delivery occurred in 4/32 (12.5%) patients with primary generalized epilepsy, but in none of the 57 women with partial epilepsy (P<0.05). None of the 38 patients with therapeutic AED levels before labor and delivery had seizures, compared to 3/37 (8.1%) of the subtherapeutic group. However, drug levels were taken at variable times in relation to delivery, limiting their value. Also, the levels sampled were both total and free levels; the latter would be more helpful to determine the adequacy of AED drug coverage. CONCLUSIONS: Maintaining therapeutic AED levels during the last trimester may help prevent seizures during labor and delivery, especially in women with generalized epilepsy. Women with epilepsy who had subtherapeutic AED levels and had been seizure-free may be at-risk for seizures during labor and delivery. Our sample was small, and a random sampling bias may have affected the results.

Adult↗

Photosensitivity in idiopathic generalized epilepsies.

Photosensitivity is an abnormal visual sensitivity of the brain in reaction to flickering light sources or patterns and is expressed in the electroencephalogram as generalized spike-and-wave discharge and in more susceptible individuals as clinical seizures. The most common types of seizures are generalized tonic-clonic, followed by myoclonic and absence. The photosensitive epilepsies are classified as pure photosensitive, where seizures occur only with the flickering light source/pattern or during intermittent photic stimulation (IPS) in the laboratory, and epilepsy with photosensitivity, where spontaneous seizures also occur. Positive response to IPS in idiopathic epilepsy syndromes, which are included in the International Classification or are in development, is reported to range from 7.5% in juvenile absence epilepsy to 100% in pure photosensitive epilepsy. The treatment of photosensitivity and pure photosensitive epilepsy with rare seizures includes general and specific protective measures. For most patients, however, combination treatment with antiepileptic drugs is necessary. Valproic acid monotherapy has a success rate of 73-86%. Levetiracetam appears to be a new alternative therapeutic option. Clobazam, lamotrigine, ethosuximide, and topiramate also have been recommended as second-choice therapies.

Anticonvulsants↗

[Various factors affecting the onset of paroxysmal nocturnal interictal activities in primary generalized epilepsy in adults].

The relationships between the states of vigilance and the interictal EEG, paroxysmal activities (PA) were studied in 20 adults with generalized primary epilepsy. Each patient was submitted to 1-5 nocturnal polygraphic recordings. Sleep and waking modify the PA densities: 8 patients had a waking PA increase, 7 a sleep PA increase and 5 exhibited no differences of PA density between sleep and waking. Within these groups there was also an influence of slow wave sleep stages on PA densities. The function of auto-correlation of PA did not exhibit any periodicity even after correction of the effects of the states of vigilance. In patients monitored several nights the evolution of the PA densities during the successive sleep cycles throughout the night did not usually reveal a clear and stable pattern.

Adolescent↗

Profile of ucb L059, a novel anticonvulsant drug, in models of partial and generalized epilepsy in mice and rats.

The novel anticonvulsant drug ucb L059 ((S)-alpha-ethyl-2-oxo-1-pyrrolidineacetamide) was evaluated in several rodent models of partial and generalized seizures. Ucb L059 (27-108 mg/kg i.p.) increased the thresholds for tonic electroconvulsions and myoclonic and clonic seizures induced by timed i.v. infusion of pentylenetetrazol (PTZ), but was ineffective in the traditional maximal electroshock seizure and s.c. PTZ seizure tests in mice and rats in doses up to 500 mg/kg. The anticonvulsant potency of ucb L059 in seizure threshold tests was similar to that of standard drugs, such as valproate. In amygdala-kindled rats, ucb L059 exerted potent anticonvulsant activity against both focal and secondarily generalized seizures at doses of 13-108 mg/kg. The adverse effects of ucb L059 were quantitated in the open field and in standard tests for motor impairment, such as the rotarod and chimney tests. Ucb L059 exerted only minimal effects on behaviour, e.g. slight hyperactivity, and did not impair muscle activity in the rotarod test in doses up to 1700 mg/kg i.p. The data indicate that ucb L059 is an interesting new anticonvulsant agent with a broad spectrum of activity and high therapeutic index.

Amygdala↗

Plasma amino acid alterations in idiopathic generalized epilepsy: an investigation in probands and their first-degree relatives.

Twenty-two plasma amino acids were determined by means of ion-exchange chromatography in 16 previously untreated patients with generalized idiopathic epilepsy and in some of their first-degree relatives (26 subjects), and the results were compared with those obtained from a group of 50 healthy controls. The patients were subsequently treated with valproic acid for one month and then reexamined. In the epileptic subjects, statistical analysis showed significant alterations in the plasma levels of a group of amino acids, including the four associated with neuro-transmission (aspartate, glutamate, glycine, taurine); aspartate, glutamate and glycine levels were also altered in the first-degree relatives. Valproic acid therapy did not affect amino acid levels. If further confirmed, these alterations might be considered possible neurochemical markers of epilepsy.

Adult↗

Habituation of orienting reaction in therapy-resistant generalized epilepsy.

A polygraphic study on resistance to habituation of the somatic, autonomic and EEG components of the orienting reaction elicited by a repetitive auditory stimulus was performed in 39 epileptics with therapy-resistant generalized seizures (TRGS) and in 119 matched subjects in two control groups. The study showed a significantly higher resistance to habituation of the orienting reaction in epileptics with TRGS vs. the normal subjects of control group I. A significantly higher resistance to habituation was also noted in epileptics with therapy-controlled generalized seizures of control group II. The correlational analysis of data showed that the severity of these habituation disturbances in epileptics with TRGS depended on the patients' age, type of electroclinical seizures, pretrial seizure frequency, type of resting EEG, administered treatment (no. of administered antiepileptic drugs/patient), daily dose, as well as on the serum level of these drugs. The multivariate regression analysis showed that the most significant predictive variables for the habituation disturbances were the pretrial seizure frequency, type of electroclinical seizures, daily dose of administered antiepileptic drugs and their serum level. The data also evidenced that the antiepileptic treatment improves the interictal habituation disturbances, the effect being the more marked as the treatment was more sustained. The above-mentioned habituation changes in epileptics with TRGS should be ascribed to some disturbances in nervous excitability.

Adolescent↗

Inhibitory control by substantia nigra of generalized epilepsy in the cat.

Previous investigations have shown that the basal ganglia may exert a regulating influence on cortical epilepsy. Stimulation of the caudate nucleus enhances cortical penicillin (PCN) spikes. Stimulation of globus pallidus internus reduces cortical spike frequency. Since the substantia nigra pars reticulata (SNpr) seems to have an inhibitory action on the ventro-anterior (VA) and ventro-lateral (VL) thalamic nuclei and thalamic neurones send an excitatory influence to the cortex, we undertook an investigation to study nigral influence on cortical epilepsy induced by PCN. Experiments were conducted on encéphale isolé cats in which steady interictal activity was induced by means of parenteral PCN administration (feline generalized PCN epilepsy). Variations occurring in cortical PCN spikes following activation of either pars compacta (SNpc) or SNpr were analyzed. Electrical stimulation of SNpc reduced spike frequency and amplitude in 19% of the total number of stimulations; SNpr stimulation significantly inhibited cortical spikes, especially in the precruciate gyrus, in 80% of cases. The experimental findings constitute an electrophysiological feature of the control exerted by SNpr on the thalamo-cortical re-exciting loop. A putative preferential role of SNpr in the regulation of abnormal phenomena involving the neocortex is emphasized.

Animals↗

[Lamotrigine in refractory partial and general epilepsies].

INTRODUCTION: Lamotrigine (LTG) is a new antiepileptic drug that it has proved to be efficacious in treating patients with partial and generalized tonic-clonic seizures in adjunctive and monotherapy. It has similar efficacy in comparison with carbamazepine and phenytoin with a minor number of adverse experiences. PATIENTS AND METHODS: We report the use of LTG in adjunctive therapy in 106 adults patients with refractory epilepsy (efficacy and safety) with partial and generalized seizures, with follow-up to 3.4 years. The LTG mean doses used was 273 mg/day. RESULTS: 66% of patients experienced a > or = 50% reduction in seizure frequency, with 30% in remission. Both partial, secondarily generalized and generalized seizures showed significant reductions with LTG treatment. LTG was well tolerated in our patients. Side effects were minor. No case of rash was seen. CONCLUSION: LTG is a excellent agent for adjunctive therapy in refractory epilepsy.

Adolescent↗

Defective stimulus set attention in generalized epilepsy.

This study examined auditory selective attention in primary generalized and complex-partial (temporal lobe) epileptics using binaural and dichotic versions of the Continuous Performance Test. The patient groups did not differ from normal controls when only one channel was presented or when divided attention (simultaneously monitoring two channels) was required. However, generalized epileptics had significantly depressed hit rates when directed attention (responding to critical stimuli in only one channel) was required. These results suggest a contribution of brain stem "arousal" mechanisms to stimulus set attention. In addition, right ear perceptual advantages were found on these dichotic monitoring tasks, lending support to the contention that short-term auditory memory and verbal report are not required for the dichotic ear effect.

Adult↗