12 research outputs found

    Infantile Spasms: Collaborative Approaches to Improve Outcomes

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    Date of Presentation: May 4th, 2023 Presented by: Tiffani McDonough, MD- Assistant Professor of Pediatrics, Tufts University School of Medicine Attending Physician, Pediatric Neurology Maine Medical Partners Neurology The Barbara Bush Children’s Hospital at Maine Medical Center CME available for 1 year after presentation CME Text Code: 84177https://knowledgeconnection.mainehealth.org/pediatrics_gr/1018/thumbnail.jp

    KCND2 variants associated with global developmental delay differentially impair Kv4.2 channel gating

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    Here, we report on six unrelated individuals, all presenting with early-onset global developmental delay, associated with impaired motor, speech and cognitive development, partly with developmental epileptic encephalopathy and physical dysmorphisms. All individuals carry heterozygous missense variants of KCND2, which encodes the voltage-gated potassium (Kv) channel alpha-subunit Kv4.2. The amino acid substitutions associated with the variants, p.(Glu323Lys) (E323K), p.(Pro403Ala) (P403A), p.(Val404Leu) (V404L) and p.(Val404Met) (V404M), affect sites known to be critical for channel gating. To unravel their likely pathogenicity, recombinant mutant channels were studied in the absence and presence of auxiliary beta-subunits under two-electrode voltage clamp in Xenopus oocytes. All channel mutants exhibited slowed and incomplete macroscopic inactivation, and the P403A variant in addition slowed activation. Co-expression of KChIP2 or DPP6 augmented the functional expression of both wild-type and mutant channels; however, the auxiliary beta-subunit-mediated gating modifications differed from wild type and among mutants. To simulate the putative setting in the affected individuals, heteromeric Kv4.2 channels (wild type + mutant) were studied as ternary complexes (containing both KChIP2 and DPP6). In the heteromeric ternary configuration, the E323K variant exhibited only marginal functional alterations compared to homomeric wild-type ternary, compatible with mild loss-of-function. By contrast, the P403A, V404L and V404M variants displayed strong gating impairment in the heteromeric ternary configuration, compatible with loss-of-function or gain-of-function. Our results support the etiological involvement of Kv4.2 channel gating impairment in early-onset monogenic global developmental delay. In addition, they suggest that gain-of-function mechanisms associated with a substitution of V404 increase epileptic seizure susceptibility

    Early Clinical Variables Associated With Refractory Convulsive Status Epilepticus in Children

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    OBJECTIVE: Determine patient-specific factors known proximate to the presentation to emergency care associated with the development of refractory convulsive status epilepticus (RSE) in children. METHODS: An observational case-control study was conducted comparing pediatric patients (1 month - 21 years) with convulsive SE whose seizures stopped after benzodiazepines (BZD) and a single second-line antiseizure medication (ASM) (responsive established status epilepticus; rESE) with patients requiring more than a BZD and a single second-line ASM to stop their seizures (RSE). These sub-populations were obtained from the pediatric Status Epilepticus Research Group (pSERG) study cohort. We explored clinical variables that could be acquired early after presentation to emergency medical services with univariate analysis of the raw data. Variables with p\u3c0.1 were retained for univariable and multivariable regression analysis. Multivariable logistic regression models were fit to age and sex- matched data to obtain variables associated with RSE. RESULTS: We compared data from a total of 595 episodes of pediatric SE. Univariate analysis demonstrated no differences in time to the first BZD (RSE 16 min (IQR 5-45); rESE 18 min (IQR 6-44), p=0.068). Time to second-line ASM was shorter in RSE patients (RSE 65 min; rESE 70 min; p=0.021). Both univariable and multivariable regression analysis revealed a family history of seizures (OR 0.37; 95% CI 0.20 -0.70, p = 0.0022) or a prescription for rectal diazepam (OR 0.21; 95% CI 0.078 - 0.53, p = 0.0012) were associated with decreased odds of RSE. CONCLUSIONS: Time to initial BZD or second-line ASM was not associated with progression to RSE in our cohort of patients with rESE. A family history of seizures and a prescription for rectal diazepam were associated with a decreased likelihood of progression to RSE. Early attainment of these variables may help care for pediatric rESE in a more patient-tailored manner. COE: This study provides class II evidence that patient and clinical factors may predict RSE in children with convulsive seizures

    Clinical presentation of new onset refractory status epilepticus in children (the pSERG cohort).

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    Objective: We aimed to characterize the clinical profile and outcomes of new onset refractory status epilepticus (NORSE) in children, and investigated the relationship between fever onset and status epilepticus (SE). Methods: Patients with refractory SE (RSE) between June 1, 2011 and October 1, 2016 were prospectively enrolled in the pSERG (Pediatric Status Epilepticus Research Group) cohort. Cases meeting the definition of NORSE were classified as "NORSE of known etiology" or "NORSE of unknown etiology." Subgroup analysis of NORSE of unknown etiology was completed based on the presence and time of fever occurrence relative to RSE onset: fever at onset (≤24 h), previous fever (2 weeks–24 h), and without fever. Results: Of 279 patients with RSE, 46 patients met the criteria for NORSE. The median age was 2.4 years, and 25 (54%) were female. Forty (87%) patients had NORSE of unknown etiology. Nineteen (48%) presented with fever at SE onset, 16 (40%) had a previous fever, and five (12%) had no fever. The patients with preceding fever had more prolonged SE and worse outcomes, and 25% recovered baseline neurological function. The patients with fever at onset were younger and had shorter SE episodes, and 89% recovered baseline function. Significance: Among pediatric patients with RSE, 16% met diagnostic criteria for NORSE, including the subcategory of febrile infection-related epilepsy syndrome (FIRES). Pediatric NORSE cases may also overlap with refractory febrile SE (FSE). FIRES occurs more frequently in older children, the course is usually prolonged, and outcomes are worse, as compared to refractory FSE. Fever occurring more than 24 h before the onset of seizures differentiates a subgroup of NORSE patients with distinctive clinical characteristics and worse outcomes.SCOPUS: ar.jinfo:eu-repo/semantics/publishe
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