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Neurological Sciences : Official... Dec 2020Since its first clinical description (on his son) by William James West (1793-1848) in 1841, and the definition of the classical triad of (1) infantile spasms; (2)... (Review)
Review
Since its first clinical description (on his son) by William James West (1793-1848) in 1841, and the definition of the classical triad of (1) infantile spasms; (2) hypsarrhythmia, and (3) developmental arrest or regression as "West syndrome", new and relevant advances have been recorded in this uncommon disorder. New approaches include terminology of clinical spasms (e.g., infantile (IS) vs. epileptic spasms (ES)), variety of clinical and electroencephalographic (EEG) features (e.g., typical ictal phenomena without EEG abnormalities), burden of developmental delay, spectrum of associated genetic abnormalities, pathogenesis, treatment options, and related outcome and prognosis. Aside the classical manifestations, IS or ES may present with atypical electroclinical phenotypes (e.g., subtle spasms; modified hypsarrhythmia) and may have their onset outside infancy. An increasing number of genes, proteins, and signaling pathways play crucial roles in the pathogenesis. This condition is currently regarded as a spectrum of disorders: the so-called infantile spasm syndrome (ISs), in association with other causal factors, including structural, infectious, metabolic, syndromic, and immunologic events, all acting on a genetic predisposing background. Hormonal therapy and ketogenic diet are widely used also in combination with (classical and recent) pharmacological drugs. Biologically targeted and gene therapies are increasingly studied. The present narrative review searched in seven electronic databases (primary MeSH terms/keywords included West syndrome, infantile spasms and infantile spasms syndrome and were coupled to 25 secondary clinical, EEG, therapeutic, outcomes, and associated conditions terms) including MEDLINE, Embase, Cochrane Central, Web of Sciences, Pubmed, Scopus, and OMIM to highlight the past knowledge and more recent advances.
Topics: Electroencephalography; Humans; Infant; Prognosis; Spasms, Infantile
PubMed: 32827285
DOI: 10.1007/s10072-020-04600-5 -
Pediatric Neurology Jul 2020Children with infantile spasms are likely to have a poor outcome. Outcome measures for infantile spasms include primary response to treatment, relapse of spasms,... (Review)
Review
Children with infantile spasms are likely to have a poor outcome. Outcome measures for infantile spasms include primary response to treatment, relapse of spasms, neurological development, death, and progression to another type of epilepsy (Consensus Statements of the WEST Delphi Group 2004). This review is based mainly on prospective studies and emphasizes data about the current first-line drugs, adrenocorticotropic hormone, vigabatrin, and prednisolone, taking into account the proportion of patients with known and unknown etiology, which has a very strong effect on seizure outcome. In most studies, hormonal treatment (adrenocorticotropic hormone or prednisolone) is the optimal monotherapy, except for patients with tuberous sclerosis complex, in whom vigabatrin appears superior. Combination therapy (hormones plus vigabatrin) may well be more effective than either agent alone. The underlying etiology is the most important prognostic factor. In studies with a long follow-up (up to 50 years), a favorable cognitive outcome has been observed in approximately one quarter of patients and complete seizure freedom in one-third. Autism is relatively frequent, and premature mortality is high throughout life. Modifiable prognostic factors include early recognition of the spasms with prompt treatment, short duration of hypsarrhythmia, prompt treatment of relapses of spasms and multifocal epileptic discharges, and early treatment of adverse effects. It is hoped that eventually advanced genetics and molecular data will allow an understanding of the pathogenetic mechanisms of many specific etiologies to allow disease-specific treatment such as is emerging for tuberous sclerosis.
Topics: Adolescent; Adrenocorticotropic Hormone; Adult; Anticonvulsants; Child; Child, Preschool; Glucocorticoids; Humans; Infant; Middle Aged; Outcome Assessment, Health Care; Spasms, Infantile; Vigabatrin; Young Adult
PubMed: 32305143
DOI: 10.1016/j.pediatrneurol.2020.01.015 -
Epilepsia Oct 2022Dravet syndrome (DS) and Lennox-Gastaut syndrome (LGS) are rare treatment-resistant childhood epilepsies classed as developmental and epileptic encephalopathies. ELEKTRA... (Randomized Controlled Trial)
Randomized Controlled Trial
A phase 2, randomized, double-blind, placebo-controlled study to evaluate the efficacy and safety of soticlestat as adjunctive therapy in pediatric patients with Dravet syndrome or Lennox-Gastaut syndrome (ELEKTRA).
OBJECTIVE
Dravet syndrome (DS) and Lennox-Gastaut syndrome (LGS) are rare treatment-resistant childhood epilepsies classed as developmental and epileptic encephalopathies. ELEKTRA investigated the efficacy and safety of soticlestat (TAK-935) as adjunctive therapy in children with DS or LGS (NCT03650452).
METHODS
ELEKTRA was a phase 2, randomized, double-blind, placebo-controlled study of soticlestat (≤300 mg twice daily, weight-adjusted) in children (aged 2-17 years) with DS, demonstrating three or more convulsive seizures/month, or with LGS, demonstrating four or more drop seizures/month at baseline. The 20-week treatment period comprised an 8-week dose-optimization period and a 12-week maintenance period. Efficacy endpoints included change from baseline in seizure frequency versus placebo. Safety assessments included incidence of treatment-emergent adverse events (TEAEs).
RESULTS
ELEKTRA enrolled 141 participants; 126 (89%) completed the study. The modified intent-to-treat population included 139 participants who received one or more doses of study drug and had one or more efficacy assessments (DS, n = 51; LGS, n = 88). ELEKTRA achieved its primary endpoint: the combined soticlestat-treated population demonstrated a placebo-adjusted median reduction in seizure frequency of 30.21% during the maintenance period (p = .0008, n = 139). During this period, placebo-adjusted median reductions in convulsive and drop seizure frequencies of 50.00% (p = .0002; patients with DS) and 17.08% (p = .1160; patients with LGS), respectively, were observed. TEAE incidences were similar between the soticlestat (80.3%) and placebo (74.3%) groups and were mostly mild or moderate in severity. Serious TEAEs were reported by 15.5% and 18.6% of participants receiving soticlestat and placebo, respectively. TEAEs reported in soticlestat-treated patients with ≥5% difference from placebo were lethargy and constipation. No deaths were reported.
SIGNIFICANCE
Soticlestat treatment resulted in statistically significant, clinically meaningful reductions from baseline in median seizure frequency (combined patient population) and in convulsive seizure frequency (DS cohort). Drop seizure frequency showed a nonstatistically significant numerical reduction in children with LGS. Soticlestat had a safety profile consistent with previous studies.
Topics: Anticonvulsants; Child; Double-Blind Method; Epilepsies, Myoclonic; Epileptic Syndromes; Humans; Lennox Gastaut Syndrome; Piperidines; Pyridines; Seizures; Spasms, Infantile; Treatment Outcome
PubMed: 35841234
DOI: 10.1111/epi.17367 -
Brain : a Journal of Neurology Jun 2022Disease-causing variants in STXBP1 are among the most common genetic causes of neurodevelopmental disorders. However, the phenotypic spectrum in STXBP1-related disorders...
Disease-causing variants in STXBP1 are among the most common genetic causes of neurodevelopmental disorders. However, the phenotypic spectrum in STXBP1-related disorders is wide and clear correlations between variant type and clinical features have not been observed so far. Here, we harmonized clinical data across 534 individuals with STXBP1-related disorders and analysed 19 973 derived phenotypic terms, including phenotypes of 253 individuals previously unreported in the scientific literature. The overall phenotypic landscape in STXBP1-related disorders is characterized by neurodevelopmental abnormalities in 95% and seizures in 89% of individuals, including focal-onset seizures as the most common seizure type (47%). More than 88% of individuals with STXBP1-related disorders have seizure onset in the first year of life, including neonatal seizure onset in 47%. Individuals with protein-truncating variants and deletions in STXBP1 (n = 261) were almost twice as likely to present with West syndrome and were more phenotypically similar than expected by chance. Five genetic hotspots with recurrent variants were identified in more than 10 individuals, including p.Arg406Cys/His (n = 40), p.Arg292Cys/His/Leu/Pro (n = 30), p.Arg551Cys/Gly/His/Leu (n = 24), p.Pro139Leu (n = 12), and p.Arg190Trp (n = 11). None of the recurrent variants were significantly associated with distinct electroclinical syndromes, single phenotypic features, or showed overall clinical similarity, indicating that the baseline variability in STXBP1-related disorders is too high for discrete phenotypic subgroups to emerge. We then reconstructed the seizure history in 62 individuals with STXBP1-related disorders in detail, retrospectively assigning seizure type and seizure frequency monthly across 4433 time intervals, and retrieved 251 anti-seizure medication prescriptions from the electronic medical records. We demonstrate a dynamic pattern of seizure control and complex interplay with response to specific medications particularly in the first year of life when seizures in STXBP1-related disorders are the most prominent. Adrenocorticotropic hormone and phenobarbital were more likely to initially reduce seizure frequency in infantile spasms and focal seizures compared to other treatment options, while the ketogenic diet was most effective in maintaining seizure freedom. In summary, we demonstrate how the multidimensional spectrum of phenotypic features in STXBP1-related disorders can be assessed using a computational phenotype framework to facilitate the development of future precision-medicine approaches.
Topics: Electroencephalography; Epilepsy; Humans; Infant; Munc18 Proteins; Retrospective Studies; Seizures; Spasms, Infantile
PubMed: 35190816
DOI: 10.1093/brain/awab327 -
CNS Drugs Jun 2022Cyclin-dependent kinase-like 5 (CDKL5) deficiency disorder (CDD) is a developmental and epileptic encephalopathy with infantile-onset epilepsy. Most individuals with CDD... (Review)
Review
Cyclin-dependent kinase-like 5 (CDKL5) deficiency disorder (CDD) is a developmental and epileptic encephalopathy with infantile-onset epilepsy. Most individuals with CDD develop refractory epilepsy with multiple seizure types. Management of seizures in CDD remains challenging for clinicians given the highly refractory nature of seizures and the limited number of disease-specific studies that offer a high level of evidence. Epileptic spasms are the most common seizure type in CDD and are more often refractory to standard first-line treatment than are spasms of other etiologies. In other seizure types, the effectiveness of antiseizure medications is limited and wanes over time. Ketogenic diet and palliative surgical treatments have both had mixed results in observational studies. When treating refractory seizures in CDD, we recommend carefully balancing seizure control and treatment-related side effects to optimize each individual's overall quality of life. Clinical trials of medications targeting epilepsy in CDD have been conducted, and additional investigational small molecules, gene therapy, and other disease-modifying therapies are in development for CDD.
Topics: Epilepsy; Epileptic Syndromes; Humans; Protein Serine-Threonine Kinases; Quality of Life; Seizures; Spasm; Spasms, Infantile
PubMed: 35633486
DOI: 10.1007/s40263-022-00921-5 -
Annals of Neurology Dec 2019Epilepsy of infancy with migrating focal seizures (EIMFS) is one of the most severe developmental and epileptic encephalopathies. We delineate the genetic causes and...
OBJECTIVE
Epilepsy of infancy with migrating focal seizures (EIMFS) is one of the most severe developmental and epileptic encephalopathies. We delineate the genetic causes and genotype-phenotype correlations of a large EIMFS cohort.
METHODS
Phenotypic and molecular data were analyzed on patients recruited through an international collaborative study.
RESULTS
We ascertained 135 patients from 128 unrelated families. Ninety-three of 135 (69%) had causative variants (42/55 previously reported) across 23 genes, including 9 novel EIMFS genes: de novo dominant GABRA1, GABRB1, ATP1A3; X-linked CDKL5, PIGA; and recessive ITPA, AIMP1, KARS, WWOX. The most frequently implicated genes were KCNT1 (36/135, 27%) and SCN2A (10/135, 7%). Mosaicism occurred in 2 probands (SCN2A, GABRB3) and 3 unaffected mothers (KCNT1). Median age at seizure onset was 4 weeks, with earlier onset in the SCN2A, KCNQ2, and BRAT1 groups. Epileptic spasms occurred in 22% patients. A total of 127 patients had severe to profound developmental impairment. All but 7 patients had ongoing seizures. Additional features included microcephaly, movement disorders, spasticity, and scoliosis. Mortality occurred in 33% at median age 2 years 7 months.
INTERPRETATION
We identified a genetic cause in 69% of patients with EIMFS. We highlight the genetic heterogeneity of EIMFS with 9 newly implicated genes, bringing the total number to 33. Mosaicism was observed in probands and parents, carrying critical implications for recurrence risk. EIMFS pathophysiology involves diverse molecular processes from gene and protein regulation to ion channel function and solute trafficking. ANN NEUROL 2019;86:821-831.
Topics: Adolescent; Child; Child, Preschool; Cohort Studies; Female; Genetic Predisposition to Disease; Humans; Infant; Male; Seizures; Spasms, Infantile
PubMed: 31618474
DOI: 10.1002/ana.25619 -
Epileptic Disorders : International... Dec 2019Benign spasms of infancy (BSI), previously described as benign non-epileptic infantile spasms or benign myoclonus of early infancy, are non-epileptic movements...
Benign spasms of infancy (BSI), previously described as benign non-epileptic infantile spasms or benign myoclonus of early infancy, are non-epileptic movements manifesting during the first year of life and spontaneously resolving in the second year of life. BSI are characterized by spasms typically lasting 1-2 seconds, involving, to varying degrees, the head, neck, trunk, shoulders and upper extremities. Ictal and interictal EEG recordings are normal. BSI are not associated with developmental regression and do not require treatment. Distinction between BSI and infantile epileptic disorders, such as epileptic spasms or myoclonic epilepsy of infancy, can be challenging given the clinical similarities. Moreover, interictal EEGs can be normal in all conditions. Epileptic spasms and myoclonic epilepsy require timely treatment to improve neurodevelopmental outcomes. We describe a six-month-old infant presenting with spasm-like movements. His paroxysms as well as a positive family history for epileptic spasms were in keeping with a likely diagnosis of West syndrome. Surprisingly, ictal video-EEG did not reveal epileptiform activity, and suggested a diagnosis of BSI. We emphasize that ictal video-EEG is the gold standard for classification of infantile paroxysms as epileptic or non-epileptic, thereby avoiding over-treatment for BSI and facilitating timely targeted treatment of infantile epilepsies. [Published with video sequences].
Topics: Diagnosis, Differential; Epilepsies, Myoclonic; Humans; Infant; Male; Spasms, Infantile
PubMed: 31843733
DOI: 10.1684/epd.2019.1116 -
Epilepsy Research Jul 2021To develop an improved interictal electroencephalogram (EEG) grading scale for children with infantile spasms founded on elements with adequate inter-rater reliability...
OBJECTIVE
To develop an improved interictal electroencephalogram (EEG) grading scale for children with infantile spasms founded on elements with adequate inter-rater reliability (IRR) to justify its further study for clinical and research purposes.
METHODS
Three blinded reviewers assessed five-minute sleep epochs in 93 EEGs from 62 children (31 consecutive controls, 31 consecutive infantile spasms [pretreatment and posttreatment studies]) using a longitudinal bipolar montage. We determined the IRR of background amplitude, epileptiform discharges, >3 spike foci (including <50 % or >50 %), grouped multifocal spikes, paroxysmal voltage attenuations, and symmetry of sleep spindles. Data were used to finalize the 2021 BASED (Burden of AmplitudeS and Epileptiform Discharges) score.
RESULTS
All elements included in the 2021 BASED score had moderate to near perfect IRR. Among controls, >200 μv background waves occurred commonly in the bilateral posterior temporal (T3-T5, T4-T6) and midline (Fz-Cz, Cz-Pz) regions. Excluding midline and occipital channels (which have normal high amplitude background waves), we designated abnormal high amplitude background waves as >200 μv for most channels, but >300 μv for T3-T5 and T4-T6. The IRR was moderate to near perfect for <50 % >3 spike foci, >50 % >3 spike foci, paroxysmal voltage attenuations, grouped multifocal spikes (GMFS), and symmetric sleep spindles. Paroxysmal voltage attenuations, GMFS, and >50 % >3 spike foci all significantly distinguished pretreatment from posttreatment studies whereas symmetric sleep spindles did not (as planned, the latter was not included in the 2021 BASED score). When the 2021 BASED score was applied to the 22 children with infantile spasms achieving clinical remission with treatment, 19 met criteria for electroclinical remission and three did not.
SIGNIFICANCE
The 2021 BASED score includes elements with high levels of IRR and correlates well with the presence or absence of infantile spasms.
Topics: Child; Electroencephalography; Humans; Infant; Reproducibility of Results; Sleep; Spasm; Spasms, Infantile
PubMed: 33839516
DOI: 10.1016/j.eplepsyres.2021.106631 -
Ugeskrift For Laeger Apr 2020Infantile spasms (IS) is a severe developmental and epileptic encephalopathy, occurring mainly in children aged 3-18 months. IS have multiple aetiologies, and the... (Review)
Review
Infantile spasms (IS) is a severe developmental and epileptic encephalopathy, occurring mainly in children aged 3-18 months. IS have multiple aetiologies, and the treatment differs accordingly. Early diagnosis and treatment may improve the outcome, but many patients are initially misdiagnosed. Evaluation includes seizure semiology, electroencephalography, cerebral magnetic resonance imaging and genetic and metabolic testing. Treatment varies among centres, and initial treatment may include vigabatrin and/or corticosteroids. In recent years, as summarised in this review, knowledge has substantially increased regarding genetic aetiologies and treatment regimens.
Topics: Anticonvulsants; Child; Electroencephalography; Humans; Infant; Magnetic Resonance Imaging; Spasms, Infantile; Vigabatrin
PubMed: 32286217
DOI: No ID Found -
Archives de Pediatrie : Organe Officiel... Dec 2022Tuberous sclerosis (TSC) epilepsy includes infantile spasms and focal seizures before the age of 2 years, whereas focal seizures are predominant over 2 years and... (Review)
Review
Tuberous sclerosis (TSC) epilepsy includes infantile spasms and focal seizures before the age of 2 years, whereas focal seizures are predominant over 2 years and generalized seizures may occasionally be part of Lennox-Gastaut syndrome. The better and earlier the seizure control, the better the child's subsequent cognitive and behavioral prognosis. As for epilepsy of other causes, therapeutic options depend on the type of seizure/epilepsy, age and drug resistance, but there are significant specificities for TSC. (1) As first-line treatment, vigabatrin is unanimously recommended for infantile spasms and focal seizures before 2 years and is also widely used for seizures over 2 years, as are levetiracetam and carbamazepine. (2) If seizures persist (about 40% of children and adolescents), cannabidiol and everolimus, an inhibitor of the mTOR pathway, have recently been approved as adjunctive therapy to the arsenal of antiseizure medications authorized for this age group and to the ketogenic diet. (3) Surgery is an essential treatment option in cases of drug resistance and should be discussed as soon as two treatments have failed. Presurgical investigations and operating techniques have recently progressed spectacularly, for example laser thermocoagulation with stereotactic location. A particularity of TSC is the possibility of sequential interventions on several epileptogenic tubers. (4) Finally, the innovative principle of initiating "pre-seizure" treatment with vigabatrin from the first months of life has just proven effective on the subsequent development of epilepsy in TSC. © 2022 French Society of Pediatrics. Published by Elsevier Masson SAS. All rights reserved.
Topics: Adolescent; Child; Humans; Child, Preschool; Vigabatrin; Spasms, Infantile; Epilepsy; Seizures; Prognosis; Anticonvulsants
PubMed: 36585066
DOI: 10.1016/S0929-693X(22)00285-8