Enhancement of Ketone Supplements-Evoked Effect on Absence Epileptic Activity by Co-Administration of Uridine in Wistar Albino Glaxo Rijswijk Rats.

Both uridine and exogenous ketone supplements decreased the number of spike-wave discharges (SWDs) in a rat model of human absence epilepsy Wistar Albino Glaxo/Rijswijk (WAG/Rij) rats. It has been suggested that alleviating influence of both uridine and ketone supplements on absence epileptic activity may be modulated by A1 type adenosine receptors (A1Rs). The first aim was to determine whether intraperitoneal (i.p.) administration of a specific A1R antagonist 1,3-dipropyl-8-cyclopentylxanthine (DPCPX; 0.2 mg/kg) and a selective adenosine A2A receptor antagonist (7-(2-phenylethyl)-5-amino-2-(2-furyl)-pyrazolo-[4,3-e]-1,2,4-triazolo [1,5-c]pyrimidine) (SCH 58261; 0.5 mg/kg) have a modulatory influence on i.p. 1000 mg/kg uridine-evoked effects on SWD number in WAG/Rij rats. The second aim was to assess efficacy of a sub-effective dose of uridine (i.p. 250 mg/kg) combined with beta-hydroxybutyrate salt + medium chain triglyceride (KSMCT; 2.5 g/kg, gavage) on absence epilepsy. DPCPX completely abolished the i.p. 1000 mg/kg uridine-evoked alleviating effect on SWD number whereas SCH 58261 was ineffective, confirming the A1R mechanism. Moreover, the sub-effective dose of uridine markedly enhanced the effect of KSMCT (2.5 g/kg, gavage) on absence epileptic activity. These results demonstrate the anti-epilepsy benefits of co-administrating uridine and exogenous ketone supplements as a means to treat absence epilepsy.

Pitfalls in the diagnosis of Jeavons syndrome: a study of 32 cases and review of the literature.

Jeavons syndrome (JS) is mainly characterized by eyelid myoclonia with or without absences. It is thought to be underdiagnosed rather than have a rare prevalence. We aimed to investigate the electroclinical features of JS to determine possible factors influencing the diagnosis. We retrospectively identified the medical records of 32 cases (0.55%) from 5,796 patients with epilepsy. The inclusion criteria were: (1) eyelid myoclonia with or without absences; (2) generalized paroxysmal activity on EEG; and (3) discharges triggered by eyelid closure and/or intermittent photic stimulation. Eighteen (56.2%) of the patients were female. The mean age at seizure onset was 8.7±5.3 years and the mean age at admission to hospital was 17.8±10.7 years. A family history of epilepsy was present in 15 (46.8%) patients. Eyelid myoclonias were noticed in six (18.7%) patients by themselves. Based on the analysis of video-EEG recordings, 26 (81.2%) patients were sensitive to eye closure, 22 (68.7%) had photoparoxysmal responses, and 16 (50%) presented with absence seizures. Ten (31.2%) patients had focal epileptic discharges. Eight (25%) patients were on monotherapy. Seven (21.8%) patients achieved seizure freedom. Three patients underwent ketogenic diet therapy, which was effective in two patients. A vagus nerve stimulator was implanted into three patients, one of whom reported seizure reduction. Eyelid myoclonias are the main seizure type of JS but are usually overlooked. The time interval between seizure onset and clinical diagnosis suggests that this syndrome continues to be under-recognized. The genetic heterogeneity and phenotypic variability are likely to be more extensive than currently recognized, making the diagnosis more phalangine. [Published with video sequence].

Infantile spasms followed by childhood absence epilepsy: A case series.

PURPOSE: Infantile spasms (IS) represent a severe seizure disorder of infancy and early childhood characterized by epileptic spasms along with hypsarrhythmia often accompanied by intellectual disability. According to the current classification and terminology (3) IS can be categorized as known etiology, formerly known as "symptomatic", when an underlying cause has been observed prior to the onset of spasms, or of "unknown cause" with "unfavorable" and "favorable" outcome (previously referred as "cryptogenic" or "idiopathic", respectively). Single reports described children with "unknown cause and favorable outcome" (UC/FO) IS who later developed childhood absence epilepsy (CAE). This study aims to determine the prevalence of CAE following IS. METHODS: a multicenter retrospective chart review was performed; children with UC/FO IS who subsequently developed CAE during follow-up were identified. Eight Italian pediatric epilepsy centers participated in this study. RESULTS: seven out of 24 (29 %) children (3 males) showing a favorable outcome (UC/FO) IS received a second diagnosis of CAE during follow-up. Mean age at IS presentation was 5.8 months (SD ± 0.9). All achieved seizure control of IS at a mean age of 8.5 months (SD ± 1.3) (3 monotherapy, 4 polytherapy). CAE was diagnosed at a mean age of 8.0 years (SD ± 3.0). Six children achieved sustained remission of CAE with valproic acid, whereas 1 child required dual therapy by adding ethosuximide. CONCLUSION: although it is not possible to determine whether the association between UC/FO IS and CAE implies a causality relationship, the later occurrence of CAE in patients with UC/FO IS might support a possible role of thalamo-cortical dysfunction.

Cav 3.2 T-type calcium channel mutation influences kindling-induced thalamic neuronal firing patterns in Genetic Absence Epilepsy Rats From Strasbourg.

OBJECTIVE: Recent data indicate that amygdala kindling leads to significant changes in interictal neuronal firing patterns of thalamic reticular nucleus (TRN) neurons by decreasing the spontaneous firing rate and increasing burst firing in nonepileptic control (NEC) rats. Genetic Absence Epilepsy Rats From Strasbourg (GAERS) were resistant to these kindling-induced firing changes in TRN neurons, and are also resistant to the progression of kindling. We investigated whether a homozygous, missense, single nucleotide mutation (R1584P) in the Cav 3.2 T-type Ca2+ channel gene, which has been correlated with the expression of absence seizures in GAERS, influenced kindling progression and TRN firing patterns. METHODS: Double-crossed (GAERS vs NEC; F2) rats that were homozygous for the Cav 3.2 mutation (PP) and those negative for the mutation (RR) were implanted with a stimulating electrode in the amygdala. Rats received a total of 30 kindling stimulations at their afterdischarge threshold current twice daily, and kindling progression was evaluated. Thereafter, the extracellular neuronal activity of TRN neurons was recorded in vivo under neuroleptanesthesia to investigate the influence of Cav 3.2 mutation on TRN firing patterns. RESULTS: We found that the R1584P mutation did not affect kindling progression in F2 crosses (P = 0.78). However, it influenced kindling-induced neuronal firing of TRN neurons. After 30 stimulations, RR rats exhibited a lower firing rate and a higher percentage of burst firing compared to PP rats. The decrease in firing frequency was correlated with the increase in the amount of burst firing in RR rats (R2  = 0.497). SIGNIFICANCE: Our findings suggest that mutation in Cav 3.2 T-type Ca2+ channels may play a role in the resistance to kindling-induced changes in TRN neurons to a low-frequency and high-percentage bursting pattern seen in association with the convulsive stages of amygdala kindling, but is not in itself enough to explain the resistance to kindling progression observed in GAERS.

Glut1 deficiency is a rare but treatable cause of childhood absence epilepsy with atypical features.

Glucose transporter type 1 deficiency syndrome (GLUT1-DS) is a rare genetic disorder caused by pathogenic variants in SLC2A1, resulting in impaired glucose uptake through the blood-brain barrier. Our objective is to analyze the frequency of GLUT1-DS in patients with absences with atypical features. Sequencing analysis and detection of copy number variation of the SLC2A1 gene was carried out in patients with atypical absences including: early-onset absence, intellectual disability, additional seizure types, refractory epilepsy, associated movement disorders, as well as those who have first-degree relatives with absence epilepsy or atypical EEG ictal discharges. Of the 43 patients analyzed, pathogenic variations were found in 2 (4.6%). Six atypical characteristics were found in these 2 patients. The greater the number of atypical characteristics presenting in patients with absence seizures, the more likely they have a SLC2A1 mutation. Although GLUT1-DS is an infrequent cause of absence epilepsy, recognizing this disorder is important, since initiation of a ketogenic diet can reduce the frequency of seizures, the severity of the movement disorder, and also improve the quality of life of the patients and their families.

The absence of NIPA2 enhances neural excitability through BK (big potassium) channels.

AIM: To reveal the pathogenesis and find the precision treatment for the childhood absence epilepsy (CAE) patients with NIPA2 mutations. METHODS: We performed whole-cell patch-clamp recordings to measure the electrophysiological properties of layer V neocortical somatosensory pyramidal neurons in wild-type (WT) and NIPA2-knockout mice. RESULTS: We identified that layer V neocortical somatosensory pyramidal neurons isolated from the NIPA2-knockout mice displayed higher frequency of spontaneous and evoked action potential, broader half-width of evoked action potential, and smaller currents of BK channels than those from the WT mice. NS11021, a specific BK channel opener, reduced neuronal excitability in the NIPA2-knockout mice. Paxilline, a selective BK channel blocker, treated WT neurons and could simulate the situation of NIPA2-knockout group, thereby suggesting that the absence of NIPA2 enhanced the excitability of neocortical somatosensory pyramidal neurons by decreasing the currents of BK channels. Zonisamide, an anti-epilepsy drug, reduced action potential firing in NIPA2-knockout mice through increasing BK channel currents. CONCLUSION: The results indicate that the absence of NIPA2 enhances neural excitability through BK channels. Zonisamide is probably a potential treatment for NIPA2 mutation-induced epilepsy, which may provide a basis for the development of new treatment strategies for epilepsy.

Loss of HCN1 subunits causes absence epilepsy in rats.

Hyperpolarized-activated cyclic nucleotide-gated (HCN) channels underlie hyperpolarization-activated current (Ih) and are involved in controlling the excitability and electrical responsiveness of neurons. Absence epilepsy is clinically defined by a sudden, brief impairment of consciousness and behavioral arrest. Spike-and-wave discharges (SWDs) on electroencephalograms (EEG) are a diagnostic hallmark of absence epilepsy. In rat models of absence epilepsy, impaired function or expression of HCN1, a subtype of HCN channels, has been found. Here, to evaluate whether HCN1 deficiency causes absence epilepsy in rats, we developed Hcn1-knockout rats by transcription activator-like effector nuclease mutagenesis. The cortical and hippocampal pyramidal neurons of these rats displayed a significant reduction of Ih, a pronounced hyperpolarizing shift of the resting membrane potential, and increased input resistance, which indicated that the Hcn1-knockout rats were deficient in HCN1 function. The Hcn1-knockout rats were also more vulnerable to pentylenetetrazol-induced acute convulsions. More importantly, they exhibited spontaneous SWDs, which were accompanied by behavioral arrest, both of which were suppressed by ethosuximide. These results confirm the involvement of the HCN1 subunit in the regulation of input resistance and provide direct evidence that a deficiency of HCN1 caused absence epilepsy in rats.

[Exercise and fasting induced movement disorder in children: think of the GLUT1 deficiency syndrome]. / Een bewegingsstoornis na inspanning en vasten bij kinderen.

BACKGROUND: Glucose transporter type 1 (GLUT1) enables glucose to pass through the blood-brain barrier. A hereditary deficiency of this protein may lead to clinical symptoms when blood glucose levels are decreasing. CASE DESCRIPTION: A 7-year-old girl with therapy-resistant childhood absence epilepsy presented with an exercise and fasting induced dystonic and atactic movement pattern. The movement pattern disappears postprandial. Based on a reduced glucose in the liquor, and also a reduced liquor glucose/serum glucose ratio, the diagnosis of GLUT1 deficiency syndrome was considered. Through genetic diagnostics a mutation of the SLC2A1 gene was identified, thereby confirming the initial diagnosis. The patient was referred to a tertiary centre for advice on following a ketogenic diet. After initiation of this treatment she no longer experienced absence epilepsy or paroxysmal dyskinesia episodes. CONCLUSION: GLUT1 deficiency syndrome is a relatively underdiagnosed disease. The recommended therapy is adherence to a ketogenic diet. With this diet the symptoms are treated, yet at the same time the further development of the brain is stimulated.

Ongoing Photosensitivity in An Elderly Patient With Jeavons Sydrome.

INTRODUCTION: Photosensitivity, which is a main feature of Jeavons syndrome, can be seen in other types of idiopathic or genetic epilepsies with focal or generalized seizures and tends to disappear spontaneously usually in the second decade. Although it responds well to antiepileptic treatment, especially to valproic acid, it may continue into adulthood in rare cases. CASE REPORT: We describe a 63-year-old male patient with eyelid myoclonia with absences, generalized tonic-clonic seizures, and severe photosensitivity accompanied by eyelid myoclonia. Seizures were treated with antiepileptic treatment, whereas photosensitivity still continued on electroencephalogram without clinical findings. CONCLUSION: Our elderly patient with Jeavons syndrome with ongoing remarkable photosensitivity demonstrated that it may continue to older ages, although it is uncommon.

Maternal care exerts disease-modifying effects on genetic absence epilepsy and comorbid depression.

WAG/Rij rats, a genetic animal model of absence epilepsy with comorbidity of depression, exhibit behavioral depression-like symptoms and spontaneous generalized spike-wave discharges (SWDs) in the EEG at the age of 6 to 8 months. The aim of the present study was to test the hypothesis that maternal care is an environmental factor which, along with genetic predisposition, may contribute to the expression of absence seizures and depression-like comorbidity later in life. To achieve this, a cross-fostering procedure was used. EEG and behavior in the forced swimming test were analyzed in WAG/Rij and Wistar offspring reared by their own mothers (non-cross-fostered), foster mothers of the same strain (in-fostered) or another strain (cross-fostered) at the age of 7 to 8 months. Maternal care and forced swimming test behavior were assessed in the dams. WAG/Rij mothers showed depression-like behavior and reduced maternal care irrespective of litter size and litter composition (own or foster pups) compared with Wistar dams. WAG/Rij offspring reared by Wistar dams with a high level of maternal care exhibited less and shorter SWDs and reduced depression-like comorbidity in adulthood compared with age-matched WAG/Rij offspring reared by their own or foster WAG/Rij mothers with a low level of maternal care. Moreover, rearing by Wistar mothers delayed the onset of absence epilepsy in WAG/Rij rats. Adoption by WAG/Rij dams did not change EEG and behavior in Wistar rats. Our study demonstrates that improvement of early care-giving environment can be used as a disease-modifying treatment to counteract epileptogenesis and behavioral comorbidities in genetic absence epilepsy.

The generation mechanism of spike-and-slow wave discharges appearing on thalamic relay nuclei.

In this paper, we use a model modified from classic corticothalamic network(CT) to explore the mechanism of absence seizures appearing on specific relay nuclei (SRN) of the thalamus. It is found that typical seizure states appear on SRN through tuning several critical connection strengths in the model. In view of previous experimental and theoretical works which were mainly on epilepsy seizure phenomena appearing on excitatory pyramidal neurons (EPN) of the cortex, this is a novel model to consider the seizure observed on thalamus. In particular, the onset mechanism is different from previous theoretical studies. Inspired by some previous clinical and experimental studies, we employ the external stimuli voltage on EPN and SRN in the network, and observe that the seizure can be well inhibited by tuning the stimulus intensity appropriately. We further explore the effect of the signal transmission delays on seizures, and found that the polyspike phenomenon appears only when the delay is sufficiently large. The experimental data also confirmed our model. Since there is a complex network in the brain and all organizations are interacting closely with each other, the results obtained in this paper provide not only biological insights into the regulatory mechanisms but also a reference for the prevention and treatment of epilepsy in future.

Seizures, syndromes, and etiologies in childhood epilepsy: The International League Against Epilepsy 1981, 1989, and 2017 classifications used in a population-based cohort.

OBJECTIVE: The study provides updated information about the distribution of seizures, epilepsies, and etiologies of epilepsy in the general child population, and compares the old and new classification systems from the International League Against Epilepsy (ILAE). METHODS: The study platform was the Norwegian Mother and Child Cohort Study. Cases of epilepsy were identified through registry linkages and sequential parental questionnaires. Epilepsy diagnoses were validated using a standardized protocol, and seizures, epilepsies, and etiologies were classified according to the old (ILAE 1981/1989) and new (ILAE 2017) classifications. Information was collected through medical record reviews and/or parental telephone interviews. RESULTS: The study population included 112,744 children aged 3-13 years at the end of follow-up on December 31, 2012. Of these, there were 606 children with epilepsy (CWE). Distribution of seizure types varied by age of onset. Multiple seizure types were common with early onset. Focal epilepsies were the most common, occurring in 317 per 100,000 children in the study population and in 59% of CWE. Generalized epilepsies were found in 190 per 100,000 (35% of CWE). CWE with onset during the first 2 years of life had an even distribution of focal and generalized epilepsies, whereas focal epilepsies became dominant at later ages of onset. A definite cause of epilepsy had been demonstrated in 33% of CWE. The ILAE 1989 classification allowed for a broad syndrome category in 93% of CWE and a defined epileptic syndrome in 37%. With the ILAE 2017 classification, 41% of CWE had a defined epileptic syndrome and 63% had either a defined syndrome or structural-metabolic etiology. SIGNIFICANCE: The distribution of seizures and epilepsies is strongly dependent on age of onset. Despite diagnostic advances, the causes of epilepsy are still unknown in two-thirds of CWE. The ILAE 2017 classifications allow for a higher precision of diagnoses, but at the expense of leaving more epilepsies classifiable only at the mode of onset level.

[Symptomatic absence seizures, the least known causation of absence seizures]. / Ausencias sintomaticas, la etiologia menos conocida de las crisis de ausencia.

INTRODUCTION: According to the 1981 International League Against Epilepsy classification, absence seizures are the paradigm of idiopathic generalised seizures of childhood. Although absences are mainly of an idiopathic origin, there are also symptomatic absences, which account for 10% of all cases of absences. It is thought that a structural pathology can favour the appearance of absences in genetically predisposed individuals. CASE REPORTS: We report the cases of two patients with symptomatic absence seizures of childhood onset. The first presented thalamic damage of a perinatal origin and the second had glucose transporter deficiency in the brain. CONCLUSION: A percentage of absence seizures in childhood are of a symptomatic origin. This occurs more frequently in children who present other types of epilepsy, focal or diffuse brain damage, and in early-onset absences.

TITLE: Ausencias sintomaticas, la etiologia menos conocida de las crisis de ausencia.Introduccion. Las crisis de ausencia son el paradigma de las crisis generalizadas idiopaticas de la infancia segun la clasificacion de la Liga Internacional contra la Epilepsia de 1981. A pesar de que las ausencias son mayoritariamente de origen idiopatico, existen ausencias sintomaticas, que suponen un 10% de los casos de ausencia. Se piensa que una patologia estructural puede favorecer la aparicion de ausencias en individuos geneticamente predispuestos. Casos clinicos. Se presentan dos pacientes con crisis de ausencia sintomaticas de inicio en la infancia. El primero muestra un daño talamico de origen perinatal, y el segundo, un deficit del transportador de glucosa cerebral. Conclusion. Existe un porcentaje de las crisis de ausencia en la infancia que presenta un origen sintomatico. Este hecho ocurre con mayor frecuencia en niños que presentan otros tipos de epilepsia, daños cerebrales focales o difusos, y en las ausencias que comienzan de forma precoz.

Neurological manifestations of atypical celiac disease in childhood.

Various typical and atypical neurological manifestations can be seen as the initial symptoms of celiac disease (CD). We suggest that gluten toxicity is the most suspicious triggering risk factor for probable pathophysiological pathways of neurological involvement in atypical CD. The medical charts of 117 patients diagnosed with atypical CD were retrieved from a tertiary center in Ankara, Turkey. Eight patients reported as having neurologic manifestations as initiating symptoms were evaluated in detail. The initial neurological manifestations of CD in our study included atypical absence, which was reported first in this study, generalized tonic-clonic seizures, complex partial seizures, severe axial hypotonia and down phenotype, multifocal leukoencephalopathy, mild optic neuritis, attention deficit hyperactivity disorder, and short duration headaches. Seizures mostly emphasizing atypical absence could be the initial presentation manifestation of CD, first described in this literature. Gluten toxicity could be one of the most powerful triggering factors for developing epilepsy in CD. Learning disorders such as attention deficit hyperactivity disorder, short duration headaches, mild optic neuritis, encephalopathy, and DS could also be the initial neurological manifestations of atypical CD. A gluten-restricted diet may improve neurological complaints, epileptic discharges, and neuropsychiatric symptoms. All we found may be a small part of the full range of neurological disorders of unknown origin related to CD. Clinical suspicion should be the rule for accurate diagnosis of the disease.

Perampanel effects in the WAG/Rij rat model of epileptogenesis, absence epilepsy, and comorbid depressive-like behavior.

OBJECTIVE: Perampanel (PER), a selective non-competitive α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-receptor antagonist, exhibits broad-spectrum anticonvulsant activity in several seizure models, but its potential disease-modifying effects have not been investigated. Because of the relevance of AMPA receptors in epileptogenesis and psychiatric comorbidities, we studied the effects of PER in the WAG/Rij rat model of epileptogenesis, absence epilepsy, and depressive-like comorbidity. METHODS: We investigated the effects of acute, subchronic, and chronic treatment with PER (0.25-3 mg/kg) on absence seizures, their development, and related psychiatric/neurologic comorbidity in WAG/Rij rats. Depression-related behavior was studied by using the forced swimming and the sucrose preference test; anxiety-related behavior by using the open field and elevated plus maze test; and memory by using the passive avoidance test. RESULTS: PER (3 mg/kg/day orally for 17 weeks starting from P30) significantly reduced the development of absence seizures at 6 months of age (1 month after treatment withdrawal), but this effect was not maintained when reassessed 4 months later. Attenuated absence seizure development was accompanied by reduced depressive-like behavior in the forced swimming test (FST), whereas no effects were observed on anxiety-related behavior and memory. Subchronic (1 and 3 mg/kg/day orally for 1 week) and acute PER (0.25-1 mg/kg, i.p.) dosing did not affect established absence seizures and behavior. SIGNIFICANCE: These results suggest that AMPA receptors are involved in mechanisms of epileptogenesis in an established model of absence epilepsy, and that these mechanisms differ from those responsible for seizure generation and spread when epilepsy has become established.

Glut1 deficiency syndrome: Absence epilepsy and La Soupe du Jour.

For some time, paediatric neurologists have recognised glucose transporter type 1 (GluT1) deficiency syndrome as a cause of intractable infantile seizures, microcephaly, developmental delay and hypoglycorrhachia in the presence of a normal plasma glucose. It is caused by mutations in the SLC2A1 gene, coding for GluT1, leading to a reduction in the available glucose transporter sites; it responds to the ketogenic diet. Recently, a wider spectrum of seizure syndromes have been associated with functional impairment of glucose transport caused by SLC2A1 mutations. These syndromes include 12% of early-onset absence epilepsy and 1% of genetic generalised epilepsies, where they represent a risk allele contributing to polygenic inheritance. We describe a young man with early-onset absence seizures and paroxysmal exercise-induced dyskinesia. While this syndrome is uncommon, it is recognisable and its diagnosis allows consideration of treatment with the ketogenic diet. We discuss the role of genetic testing in early-onset absence seizures and genetic generalised epilepsy.

The role of the substantia nigra pars reticulata in kindling resistance in rats with genetic absence epilepsy.

OBJECTIVE: Genetic Absence Epilepsy Rats from Strasbourg (GAERS) show a resistance to secondary generalization of focal limbic seizures evoked by kindling. The substantia nigra pars reticulata (SNR) is involved in the propagation and modulation of seizures in kindling. We first examined the role of the SNRanterior and SNRposterior subregions in the resistance to the development of kindling in GAERS. Subsequently, to determine whether kindling resistance relates to differential sensitivity of γ-aminobutyric acid γ-aminobutyric acid (GABA)ergic or dopaminergic SNR neurons to kindling, we studied the effects of kindling-inducing stimulations on parvalbumin (PRV; GABAergic neuron marker) or tyrosine hydroxylase (TH; dopaminergic neuron marker) immunoreactivity (ir), respectively, in GAERS and in nonepileptic control (NEC) Wistar rats that lack kindling resistance. METHODS: Adult male GAERS were implanted with a stimulation electrode in the amygdala, and bilateral injection cannulas for lidocaine or saline injection (30 min before each kindling stimulation until the animals reached three stage 5 seizures or the 22 stimulations) into the SNRanterior or SNRposterior . In another experiment, PRV-ir in SNRanterior and SNRposterior and TH-ir in SNRposterior only were densitometrically compared in GAERS-SHAM, NEC-SHAM GAERS-STIM, and NEC-STIM animals (6 kindling stimulations). RESULTS: Bilateral SNRposterior infusions of lidocaine eliminated the kindling resistance and resulted in stage 5 generalized motor seizures in all kindled rats. Bilateral lidocaine infusions in the SNRanterior failed to alter the kindling resistance in GAERS. PRV-ir in the SNRposterior was unaltered in GAERS-STIM but increased in NEC-STIM group. Cellular TH-ir in the SNRposterior significantly increased by kindling stimulations in both NEC-STIM and GAERS-STIM groups. SIGNIFICANCE: The kindling resistance in GAERS is mediated by the SNRposterior in a lidocaine-sensitive manner. The insensitivity to kindling stimulation of PRV-ir in SNRposterior of GAERS but not NEC rats, implicate GABAergic SNRposterior neurons in kindling resistance. In contrast, the observed stimulation-specific increase in TH-ir in the SNRposterior is unrelated to kindling resistance.

Do pure absence seizures occur in myoclonic epilepsy of infancy? A case series.

PURPOSE: To assess if absence seizures (ASs) occur in patients with myoclonic epilepsy of infancy (MEI). METHODS: A retrospective chart review was conducted in 37 patients with MEI followed at seven different paediatric epilepsy centres in Italy, between 2002 and 2014. To assess the possible occurrence of pure ASs or absences associated with myoclonias, ASs were defined according to the following criteria: (i) a sudden onset and interruption of ongoing activities; (ii) bilateral polyspikes or spike-and-wave (SW) complexes; spike SW complexes at 2-4Hz; (iii) duration of AS: 3-30seconds. RESULTS: Thirty-seven MEI patients (25 boys and 12 girls) were identified. Nine patients (24.3%) had a history of simple FS during the first year of life. Ten patients (27%) had a family history of epilepsy, and six patients (16.2%) had a family history of FS. In 7/37 (18.9%) patients, during the occurrence of MSs, a total of nineteen brief ASs were captured by video-EEG recordings. ASs occurred both during a brief cluster of rhythmic MSs than after single myoclonic jerks. The ictal EEG abnormalities observed in patients with ASs were similar to the ictal EEG patterns associated with only myoclonias. No differences in relation to gender, family history, ictal EEG discharge were found between patients with myoclonic seizures with ASs and myoclonias without ASs. CONCLUSIONS: Absence seizures can occur in approximately 20% of MEI patients and the occurrence of ASs, though not essential to formulate the diagnosis, do not automatically exclude the diagnosis of MEI.