Childhood-onset Epileptic Encephalopathy Research Articles

Comparative Analysis of Lennox-Gastaut Syndrome With Different Subtypes of Tonic Seizures: A Single-Center Retrospective Cohort Study

BackgroundLennox-Gastaut syndrome (LGS) is one of the most severe childhood-onset epileptic encephalopathies, primarily characterized by tonic seizures. In clinical practice, we have identified various subtypes of tonic seizures in LGS. This study aimed to analyze the clinical characteristics, electrographic features, treatment responses, and prognosis across different subtypes of LGS. MethodsThis retrospective cohort study included 46 patients diagnosed with LGS at our center between January 2017 and January 2020. Patients were classified into four groups based on tonic seizure subtypes: Group A (tonic), Group B (spasm-tonic), Group C (myoclonic-tonic), and Group D (combination of spasm-tonic and myoclonic-tonic). Comprehensive clinical data were collected and analyzed. ResultsOf the 46 patients, 33 were male. The mean age of onset for Group B (12.38 ± 7.85 months) was significantly less than those of the other three groups (P = 0.02). No significant differences in etiology were found among the groups. Genetic analysis identified mutations in SCN8A, MCCC2, STXBP1, GABRB3, and CACNA1H. After a minimum follow-up of 24 months, the treatment outcomes were more favorable in Groups A and C, whereas psychomotor development was notably poorer in Groups B and D. ConclusionsThe findings of this study suggest that LGS may present with distinct subtypes of tonic seizures, with spasm-tonic seizures presenting at an earlier age. Patients with LGS experiencing spasm-tonic seizures, with or without myoclonic-tonic seizures, exhibited poorer treatment responses and psychomotor development than those with other subtypes.

P.036 Vagal nerve stimulation in three cases of continuous spike and wave in slow-wave sleep

Background: Continuous spike and waves during slow-wave sleep (CSWS) is a childhood-onset epileptic encephalopathy that is characterized by clinical seizures, electrical status epilepticus during sleep (ESES), and neurocognitive regression. Early intervention can preserve neurocognitive development, and vagus nerve stimulator (VNS) therapy had positive outcomes in the few previously reported case reports. We present three patients with intractable CSWS unresponsive to medications, who had a positive response to VNS therapy. Methods: Review of clinical records of three pediatric patients diagnosed with CSWS were compared for selected clinical outcomes and electrographic data both prior to and in the years following the initiation of VNS therapy. Results: Three patients now aged 13, 16 and 20 years, were treated with VNS following intolerance and a lack of response to multiple medications (5-9) for CSWS. The ketogenic diet was not an option. The CSWS resolved in all three patients, resulting in improved cognitive function. Patient 3 had resurgence of CSWS on EEG when the VNS settings inadvertently reset to the factory settings and improved with adjustment in the cycling. Conclusions: In patients who are unresponsive to medication, VNS provides an alternative option for resolving CSWS to preserve and, in some cases, potentially restore neurocognitive function.

Placebo response in patients with Dravet syndrome: Post-hoc analysis of two clinical trials

ObjectiveDravet syndrome is a rare, early childhood-onset epileptic and developmental encephalopathy. Responses to placebo in clinical trials for epilepsy therapies range widely, but factors influencing placebo response remain poorly understood. This study explored placebo response and its effects on safety, efficacy, and quality of life outcomes in patients with Dravet syndrome. MethodsWe performed exploratory post-hoc analyses of pooled data from placebo-treated patients from the GWPCARE 1B and GWPCARE 2 randomized controlled phase III trials, comparing cannabidiol and matched placebo in 2–18 year old Dravet syndrome patients. All patients had ≥4 convulsive seizures during a baseline period of 4 weeks. Results124 Dravet syndrome-treated patients were included in the analysis (2–5 years: n = 35; 6–12 years: n = 52; 13–18 years: n = 37). Convulsive seizures were experienced by all placebo group patients at all timepoints, with decreased median convulsive seizure frequency during the treatment period versus baseline; the number of convulsive seizure-free days was similar to baseline. Convulsive seizure frequency had a nominally significant positive correlation with age and a nominally significant negative correlation with body mass index. Most placebo-treated patients experienced a treatment-emergent adverse event; however, most resolved quickly, and serious adverse events were infrequent. Placebo treatment had very little effect on reported Caregiver Global Impression of Change outcomes versus baseline. InterpretationPlacebo had little impact on convulsive seizure-free days and Caregiver Global Impression of Change versus baseline, suggesting that these metrics may help differentiate placebo and active treatment effects in future studies. However, future research should further assess placebo responses to confirm these results.

Novel Loss-of-Function Variants in CHD2 Cause Childhood-Onset Epileptic Encephalopathy in Chinese Patients.

Developmental and epileptic encephalopathy-94 (DEE94) is a severe form of epilepsy characterized by a broad spectrum of neurodevelopmental disorders. It is caused by pathogenic CHD2 variants. While only a few pathogenic CHD2 variants have been reported with detailed clinical phenotypes, most of which lack molecular analysis. In this study, next-generation sequencing (NGS) was performed to identify likely pathogenic CHD2 variants in patients with epilepsy. Three likely pathogenic variants were finally identified in different patients. The seizure onset ages were from two years to six years. Patients 1 and 2 had developmental delays before epilepsy, while patient 3 had intellectual regression after the first seizure onset. The observed seizures were myoclonic, febrile, and generalized tonic-clonic, which had been controlled by different combinations of antiepileptic drugs. Two de novo (c.1809_1809+1delGGinsTT, p.? and c.3455+2_3455+3insTG, p.?) and one maternal (c.3783G>A, p.W1261*) variant were identified, which were all predicted to be pathogenic/likely pathogenic. Molecular analysis was performed in patient 1, and we detected aberrantly spliced products, proving the pathogenicity of this CHD2 variant. New cases with novel variants, along with a detailed clinical and molecular analysis, are important for a better understanding of CHD2-related epileptic encephalopathy.

Efficacy and Tolerability of Lacosamide in Lennox-Gastaut Syndrome: A Systematic Review and Meta-analysis.

Purpose Lennox–Gastaut syndrome (LGS) is one of the most difficult to treat childhood-onset epileptic encephalopathies. There is growing evidence that lacosamide is safe and efficacious in patients and adults with refractory epilepsy. However, the evidence regarding the efficacy of lacosamide in LGS is controversial so far. We aimed to evaluate the efficacy and tolerability of lacosamide in patients with LGS. Methods We conducted a systematic review on MEDLINE, EMBASE, COCHRANE CENTRAL, Google Scholar, and Web of Science, collating all available literature till July 31, 2020. The qualitative review included case reports, case series, and both controlled/uncontrolled trials as well as retrospective studies, but for determining pooled estimates, we only included studies with a sample size of 5 or more. The primary outcome was the efficacy of lacosamide in patients with LGS. Clinical variables related to efficacy and adverse events attributed to lacosamide were extracted from each publication. The pooled estimate of variables related to these parameters was performed using a random-effect model. Results Of the 68 items identified by the search, 14 were reviewed as full-text. Eleven articles including two prospective and six retrospective studies fulfilled eligibility criteria and described outcomes in 81 patients (42 adults, 39 children, 60% male, range—1.4–61 years). On average, 35.2%, 27.9%, 7.3%, and 29.4% patients had > 50% reduction, < 50% reduction, no change, and worsening of seizure frequency, respectively. Although 36% of patients had adverse events like somnolence, behavioral abnormalities including irritability, aggressiveness, nausea, tremor, memory problems, dizziness, gastrointestinal discomfort, vomiting, and weight loss, no serious adverse events were noted. Conclusion The evidence available in the current literature is not sufficient to support or refute the use of lacosamide in patients with LGS. Although it is one of the possible therapeutic options worth exploring in patients with LGS, caution is still necessary, as there are reports of worsening of seizure frequency in some patients.

The unchanging face of Lennox-Gastaut syndrome in adulthood

PurposeLennox-Gastaut syndrome (LGS) is a severe childhood-onset epileptic encephalopathy characterized by the presence of multiple types of intractable seizures, cognitive impairment, and specific electroencephalogram (EEG) patterns. The aim of this study was to investigate the electroclinical features of patients with LGS during adulthood. MethodsWe retrospectively identified the medical records of 20 patients aged over 18 years with a diagnosis of LGS from 3896 patients with epilepsy. ResultsThirteen (65 %) patients were male. The mean age of the patients was 23.4 ± 7.1 (min-max; 18–43) years, and the mean follow-up period was 5.6 ± 4.5 (min-max; 1–14) years. The etiology was identified in 11 (55 %) patients. None of the patients achieved seizure freedom. The most prevalent seizure types were atypical absences in 14 (70 %) patients, tonic seizures in 13 (65 %) patients, and atonic seizures in 11 (55 %) patients. One (5 %) patient was diagnosed as having psychogenic non-epileptic seizures. Mental retardation was reported in all patients and only half of them could walk independently. All patients had drug-resistant seizures and 16 (80 %) patients were on polytherapy. A vagus nerve stimulator was implanted into ten (50 %) patients and five reported 50–80 % seizure reduction. Ketogenic diet was administered to two (10 %) patients and epilepsy surgery was performed in two (10 %) patients with no significant benefit. ConclusionsPaying attention to all factors of seizure outcomes, cognitive impairment, and ambulatory status, all patients were dependent on caregivers for daily living abilities. LGS has life-long persistence with poor outcomes, even during adulthood.

Epilepsy with myoclonic-atonic seizures (Doose syndrome): Clarification of diagnosis and treatment options through a large retrospective multicenter cohort.

Epilepsy with myoclonic-atonic seizures (EMAS) is a rare childhood onset epileptic encephalopathy. There is no clear consensus for recommended treatments, and pharmacoresistance is common. To better assess the clinical phenotype, most effective treatment, and determinants of cognitive and seizure outcomes, three major pediatric epilepsy centers combined data, creating the largest cohort of patients with EMAS ever studied to date. Authors performed a retrospective chart review of patients with EMAS who received care at the authors' institutions. A total of 166 children were identified. Global developmental delay (>1 domain) was present in 2% of children at onset and 49% during the course of the disease. Afebrile seizures occurred after the age of 2years in 88%, generalized tonic-clonic seizures in 60%, and drop attack or myoclonic seizures in 30%. At onset, electroencephalography (EEG) found 28% normal, background slowing in 20%, and epileptiform discharges or seizures in 69%. Subsequent EEG found slowing in 62% and discharges or seizures in 90%. Response (>50% seizure reduction) to the first three antiseizure drugs (ASDs) was 26% (levetiracetam, 17%; valproic acid, 31%; other ASDs combined, 26%). Diet therapy was used as a second or third therapy in 19% and ultimately used in 57%; response was 79%, significantly greater than the first three ASDs (P=.005, χ2 ). Seizure freedom occurred in 57% and was less likely in the case of persistent global developmental delays (P<.001), seizure recorded on subsequent EEGs (P=.027), and failure to respond to diet therapy (P=.005). Development was normal in 47%, and 12% had delays in one domain, which was less likely in the case of global developmental delay after epilepsy onset (P<.001) and failure to achieve seizure freedom (P<.001). This large cohort of children with EMAS clarifies areas of variability in practice. Diet therapy is by far the most effective treatment; failure to respond was associated with failure to attain seizure freedom. This therapy should be used early in the treatment in EMAS. This study also identified a bidirectional link between cognitive and seizure outcomes.

Epilepsy surgery for pediatric patients with mild malformation of cortical development

PurposeThe observation of mild malformation of cortical development (mMCD) has yet to have a major clinical impact due to the lack of clinical and research data. We characterized the clinical features, surgical outcomes, and postoperative seizure control patterns in pediatric patients with mMCD. MethodsWe examined 40 patients with isolated mMCD who underwent resective surgery during a 10-year period. ResultsThe median age at seizure onset was 1.2 years, and the median age at surgery was 7.9 years. Twenty-seven patients (67.5%) presented with childhood-onset epileptic encephalopathy (21 Lennox-Gastaut syndrome, 6 West syndrome), and 13 patients (32.5%) presented with intractable focal epilepsy (10 extratemporal lesions, 3 temporal lesions). Twenty-one patients (52.5%) showed “suspected focal cortical malformation” on MRI, whereas 16 patients (40.0%) and 3 patients (7.5%) showed normal MRI findings or mild brain atrophy, respectively. The most common surgical procedures were two lobar resections (18 patients, 45.0%), followed by unilobar resections (12 patients, 30.0%) and resections exceeding two lobar boundaries (10 patients, 25.0%). As a final surgical outcome, 24 patients (60.0%) were ILAE Class 1−3. Discontinuation of all AEDs was possible for 36.8% of ILAE Class 1 patients. Regarding the seizure control pattern, fluctuating seizure control was observed most frequently (21 patients, 52.5%). ConclusionOur results suggest that mMCD is an important pathological finding in children related to a significant degree of epileptogenicity, and resective surgery can have positive outcomes. However, these patients showed unstable postoperative seizure control patterns with a high rate of late recurrence, suggesting difficulties in the surgical treatment of intractable epilepsy.

Childhood-onset epileptic encephalopathy due to FGF12 exon 1-4 tandem duplication.

Fibroblast growth factor 12 ( FGF12 ) spans 5 exons and encodes for a cytosolic voltage-gated sodium channel binding protein that modulates neuronal excitability.1,2 A recurrent activating FGF12 mutation (NM_021032, [GRCh37] 192053223C>T, p.R114H in A-isoform, p.R52H in B-isoform) causes epileptic encephalopathy (EE) with neonatal onset and intellectual disability (ID).2–6 Recently, a tandem duplication involving exons 1–4 of the FGF12 gene was related to a later onset EE phenotype.7 Here, we characterize a second case harboring a FGF12 exon 1–4 duplication. This study makes use of data generated by the DECIPHER community. A full list of centers that contributed to the generation of the data is available at [decipher.sanger.ac.uk][1] and can be shared via email upon request (decipher{at}sanger.ac.uk). Funding for the project was provided by the Wellcome Trust. The authors thank Prof. Dr. Phillip Pearl, Boston, Harvard Medical School, for discussion on current EEG terminology commonly used in the United States. [1]: http://decipher.sanger.ac.uk

Association of a de novo nonsense mutation of the TRIM8 gene with childhood-onset focal segmental glomerulosclerosis.

Focal segmental glomerulosclerosis (FSGS) is an etiologically heterogeneous disorder. Genetic FSGS may be either limited to the kidney or part of a genetic syndrome with other systemic involvement. At least 21 and 34 genes have been reported for renal-limited and syndromic FSGS, respectively. The TRIM8 gene encodes a tripartite motif protein, which is an E3 ubiquitin-protein ligase that promotes proteasomal degradation of the suppressor of cytokine signaling 1 (SOCS1) and participates in the activation of interferon-gamma signaling. The TRIM8 gene is expressed in various tissues including the kidney and the central nervous system (CNS). An association between a mutation in the TRIM8 gene and childhood-onset FSGS has not been well established. We describe an 8-year-old Hispanic male with infantile onset motor and developmental delay, seizures, and proteinuria secondary to FSGS. Next generation sequencing revealed a heterozygous de novo pathogenic variant in the TRIM8 gene (C1380T>A, p.Tyr460*). Immunohistochemical staining using anti-TRIM8 and anti-SOCS1 antibodies showed no significant TRIM8 expression and strong expression of SOCS1 in the renal biopsy tissue. De novo truncating mutations of TRIM8 have been previously reported in childhood-onset epileptic encephalopathy. A molecular analysis of TRIM8 should be considered in children with FSGS and clinical abnormalities of the central nervous system.

Asymmetric Slow-Spike-Wave Patterns with Maximal Discharges Contralateral to MRI Lesions Predict Better Surgical Prognosis in Symptomatic Lennox-Gastaut Syndrome or Lennox-Gastaut Phenotypes

Introduction: Lennox-Gastaut syndrome (LGS) is a severe subtype of childhood-onset epileptic encephalopathy with drug-resistant and poor surgical prognosis. However, electroencephalogram (EEG) patterns of symptomatic LGS or LG phenotypes with structural brain lesions including focal abnormalities or asymmetric slow-spike-wave (SSW) patterns remain largely unknown. Due to the contradictory lateralization difference between MRI lesions and EEG pattern in symptomatic LGS or LG phenotypes, it is difficult to determine the precise lateralization of epileptic lesions, which is crucial to better surgical prognosis. This study is aim to ascertain the clinical characteristics of the EEG patterns, and its relationship with MRI lesions and to evaluate its prognostic value of surgical treatment in symptomatic LGS or LG phenotypes. Methods: Twenty-four symptomatic LGS cases with asymmetric EEG SSW patterns and contralaterally independent or contralaterally dominant MRI lesions were collected, and their clinical features were analyzed retrospectively. Results: In this cohort, most of lesions were perinatal or acquired during the first 6 months of life. The most common etiology was intracerebral hemorrhage. The LGS patients with both asymmetric SSW and focal sporadic epileptic waves (SEW) patterns showed the best surgical outcome with Engel class I level. Asymmetric SSW patterns with maximal discharges contralateral to MRI lesions were frequently observed in most of symptomatic LGS or LG phenotypes. Predominantly diffuse destructive lesions led to an attenuated voltage of ipsilateral scalp EEG producing an asymmetric SSW pattern in those patients with symptomatic LGS or LG phenotypes. Conclusions: Our study reveals a special SEW EEG pattern in symptomatic LG patients with asymmetric SSW and MRI lesions contralateral to the dominant EEG patterns. Contradictory lateralization difference between MRI and EEG probably arises from the relative voltage attenuation presenting in EEG ipsilateral to huge destructive lesions from early life. Our study suggests that the independent focal SEW activity remaining ipsilateral to the MRI lesion can potentially predict better surgical prognosis in symptomatic LGS or LG phenotypes.

Lennox-Gastaut Syndrome: In a Nutshell.

Lennox-Gastaut syndrome is one of the rare childhood-onset epileptic encephalopathies, characterized by multiple type seizure disorder, the typical pattern on electroencephalogram and intellectual disability. Tonic-type seizures are most commonly seen in these patients. Behavioral disturbances and cognitive decline are gradual-onset and last long after the first episode of epileptiform activity. In most cases, there is some identifiable cause that has led to the clinical presentation of the patient. Various pharmacological and surgical procedures have been proposed for the treatment of Lennox-Gastaut syndrome and many more to come in the very near future to overcome the drug resistance and to avoid the patient forming a life-long dependency.

Variable expressivity of a likely pathogenic variant in KCNQ2 in a three-generation pedigree presenting with intellectual disability with childhood onset seizures.

KCNQ2 has been reported as a frequent cause of autosomal dominant benign familial neonatal seizures. De novo likely pathogenic variants in KCNQ2 have been described in neonatal or early infantile onset epileptic encephalopathy patients. Here, we report a three-generation family with six affected patients with a novel likely pathogenic variant (c.628C>T; p.Arg210Cys) in KCNQ2. Four family members, three adults and a child, presented with a childhood seizure onset with variability in the severity of seizures and response to treatment, intellectual disability (ID) as well as behavioral problems. The two youngest affected patients had a variable degree of global developmental delay with no seizures at their current age. This three-generation family with six affected members expands the phenotypic spectrum of KCNQ2 associated encephalopathy to KCNQ2 associated ID and or childhood onset epileptic encephalopathy. We think that KCNQ2 associated epileptic encephalopathy should be included in the differential diagnosis of childhood onset epilepsy and early onset global developmental delay, cognitive dysfunction, or ID. Furthermore, whole exome sequencing in families with ID and history of autosomal dominant inheritance pattern with or without seizures, may further broaden the phenotypic spectrum of KCNQ2 associated epileptic encephalopathy or encephalopathy.

Childhood-Onset Epileptic Encephalopathy Associated With Isolated Focal Cortical Dysplasia and a Novel TSC1 Germline Mutation.

Tuberous sclerosis complex (TSC) is an autosomal-dominant inheritable neurocutaneous disease due to mutations within the TSC1 and TSC2 genes. Many patients present with West syndrome, a severe epilepsy syndrome characterized by the triad of infantile spasms, an interictal electroencephalogram (EEG) pattern termed hypsarrhythmia (continuous slow activity with an amplitude higher than 300 µV and multiregional spikes/polyspikes/sharp waves) and developmental regression. In this study, we report on a previously healthy patient with positive family history of epilepsy with new-onset epileptic encephalopathy at the age of 9 years. Clinical signs alone were not sufficient to establish the diagnosis of TSC but epilepsy panel screening revealed a novel frameshift mutation (c.90delA; p.Glu31Argfs*12) within the TSC1 gene. Segregation gene analysis detected the same mutation in the mother. Cranial magnetic resonance imaging (MRI) studies from the index patient and his mother revealed a similar pattern of isolated subcortical white matter lesions resembling most likely focal cortical dysplasia (FCD) type IIb. In summary, in these 2 related patients, a novel TSC1 frameshift mutation was associated with an isolated FCD type IIb in the absence of further CNS abnormalities usually encountered in patients with TSC, fostering our understanding of the broad mutation spectra in the TSC1 gene and the close relationship between cortical tubers and FCD type IIb.

Ophthalmologic Features of Lennox-Gastaut Syndrome.

PurposeTo describe the characteristics and frequency of ophthalmologic findings in patients with Lennox-Gastaut syndrome (LGS).MethodsThe medical records of patients diagnosed with LGS at Seoul National University Children's Hospital from January 2004 to August 2014 were retrospectively reviewed. The records of 34 patients (mean age ± standard deviation, 2.66 ± 3.51 years; male, 58.8%) were reviewed. The primary measure was the incidence of ophthalmologic manifestations.ResultsOf the 34 patients, 88.2% had at least one ocular abnormality. Refractive error (52.9%) was the most frequently observed ophthalmologic manifestation in patients with LGS, followed by strabismus (32.4%), cortical visual impairment (23.5%), and retinopathy of prematurity (8.8%). Among these cases, seven patients had exotropia and three had esotropia.ConclusionsLGS is a childhood-onset epileptic encephalopathy with variable ophthalmologic manifestations, the most frequent being refractive errors. Patients with suspected LGS should be examined regularly because ophthalmological features can change during their disease course.

D.01 Earlier treatment with the Ketogenic Diet improves seizure outcome in early-onset drug-resistant epilepsy

Background: The ketogenic diet (KD) is used to treat severe childhood-onset epileptic encephalopathies, such as Infantile Spasms (IS). Unfortunately, limited resources for KD initiation result in treatment delays. We ask if earlier KD treatment of early-onset drug-resistant epilepsy results in better seizure outcomes. Methods: Children who started KD before age 4 years between 2000-present at SickKids Hospital were identified. Six-month seizure outcome was calculated as percent of pre-diet baseline seizure frequency (BSF). Results: 67 children were identified. 30 (44.8%) started KD &lt;2 years old, 37 (55.2%) started KD 2-4 years old. Among &lt;2 years old group, 83.3% achieved 50% reduction in BSF and 36.7% achieved 90% reduction. Among 2-4 year old group, 62.2% achieved 50% reduction in BSF and 24.3% achieved 90% reduction. 38 children had a history of IS; 17 with IS at diet initiation and 21 with past history of IS. 41.2% of the spasms cohort achieved 90% reduction in BSF, compared to 23.8% of the post-spasms cohort. Conclusions: KD was more effective when started before age 2 years than 2-4 years, and more effective in children with IS than in children with past history of IS. A rapid protocol for KD initiation in young infants and children may improve long-term outcomes

RUFINAMIDE (INOVELON) IN THE TREATMENT OF LENNOX–GASTAUT SYNDROME (A REVIEW OF LITERATURE AND CLINICAL CASE)

Lennox–Gastaut syndrome (LGS) is childhood-onset epileptic encephalopathy manifested by frequent polymorphic seizures, including tonic axial, obvious cognitive impairments, characteristic ECG changes, and therapeutic resistance. Due to the concurrence of several types of seizures in the clinical presentation of the disease and their resistance to drug therapy, great hopes are pinned on the design of novel antiepileptic drugs with fundamentally other mechanisms of action and aimed specially at treating this severe type of epilepsy. The authors review the foreign literature on the new antiepileptic drug rufinamide (Inovelon) registered in Russia in January 2015 to directly treat LGS as adjunctive treatment in children 4 years and older and adults. Multiple trials have demonstrated that rufinamide has efficacy and good tolerability in treating LGS. The authors describe an observed case of the efficacy of rufinamide in a 17-year-old male patient with LGS. Despite the drug resistance of epilepsy and no response to multiple antiepileptic drugs used alone and in different combinations, the incorporation of rufinamide into a treatment regimen had a pronounced therapeutic effect: the frequency of convulsive seizures decreased by 70 %. At the time of writing this paper, the patient has been receiving rufinamide for more 5 months. He has been tolerating the therapy well.

RUFINAMIDE IN THE TREATMENT OF LENNOX–GASTAUT SYNDROME: REVIEW OF FOREIGN LITERATURE

Lennox–Gastaut syndrome (LGS) is childhood-onset epileptic encephalopathy characterized by frequent polymorphic seizures, including tonic, axial, obvious cognitive impairments, interictal EEG slow spike-wave discharges with fast activity at 10–20 Hz, which are frequently associated with tonic seizures and resistance to therapy. Treatment for LG presents great challenges due to the fact that its clinical picture is characterized by a concurrence of a few types of seizures and their resistance to drug therapy. In this connection, there are great expectations for the design of new antiepileptic drugs that have radically other mechanisms of action and must aim specially for the treatment of this severe form of epilepsy. The authors review the foreign literature on the use of the new in Russia antiepileptic drug rufinamide (Inovelon) registered just for the treatment of adult patients and in children who are at least 4 years old. Rufinamide (Inovelon) was registered in Russia in January 2015 as adjunctive treatment of seizures associated with LGS in patients from 4 years of age. The paper describes the mechanism of action, pharmacokinetics, efficacy, and tolerability of rufinamide in LGS. Numerous trials have demonstrated the efficacy and good tolerability of rufinamide in the treatment of LGS.

CACNA1A haploinsufficiency causes cognitive impairment, autism and epileptic encephalopathy with mild cerebellar symptoms.

CACNA1A loss-of-function mutations classically present as episodic ataxia type 2 (EA2), with brief episodes of ataxia and nystagmus, or with progressive spinocerebellar ataxia (SCA6). A minority of patients carrying CACNA1A mutations develops epilepsy. Non-motor symptoms associated with these mutations are often overlooked. In this study, we report 16 affected individuals from four unrelated families presenting with a spectrum of cognitive impairment including intellectual deficiency, executive dysfunction, ADHD and/or autism, as well as childhood-onset epileptic encephalopathy with refractory absence epilepsy, febrile seizures, downbeat nystagmus and episodic ataxia. Sequencing revealed one CACNA1A gene deletion, two deleterious CACNA1A point mutations including one known stop-gain and one new frameshift variant and a new splice-site variant. This report illustrates the phenotypic heterogeneity of CACNA1A loss-of-function mutations and stresses the cognitive and epileptic manifestations caused by the loss of CaV2.1 channels function, presumably affecting cerebellar, cortical and limbic networks.

Outcomes of epilepsy surgery in childhood-onset epileptic encephalopathy

Purpose: to evaluate the outcomes and role of epilepsy surgery in children with intractable epileptic encephalopathy (EE). Methods: ninety-five children (64 boys, 31 girls) with intractable EE were treated by epilepsy surgery at Severance Children’s Hospital from 2003 to 2008. Surgical treatments included lobar resection, hemispherotomy and corpus callosotomy (CC). Seventy-six children were Lennox–Gastaut syndrome (LGS), and 19 had West syndrome. Results: of the 76 patients with LGS, CC was performed in 37 patients (48.7%), lobar resection in 29 (38.2%) and hemispherotomy in 10 (13.2%). Of the 19 patients with West syndrome, respective surgery was performed in 15 patients (78.9%) and CC in 4 (21.1%). Of the patients receiving respective surgery, Engel’s class I outcomes were achieved for 24 of 39 (61.5%) of LGS patients, and for 9 of 15 (60.0%) of West syndrome. Malformations of cortical development were commonly observed, appearing in 73.5% (36/49). In neuropsychiatric tests, 19 of 27 with LGS demonstrated improvement in postoperative cognitive function. More significant intellectual improvement correlated well with shorter epilepsy duration, good seizure outcomes, and decreased number of antiepileptic drugs. Conclusions: epilepsy surgery should be considered in treating childhood intractable EE with expectation of improvement of both seizure and cognitive outcomes, even in cases of LGS.