Cardiac arrhythmias in Dravet syndrome: an observational multicenter study
ANNALS OF CLINICAL AND TRANSLATIONAL NEUROLOGY
Authors: Shmuely, Sharon; Surges, Rainer; Helling, Robert M.; Gunning, W. Boudewijn; Brilstra, Eva H.; Verhoeven, Judith S.; Cross, J. Helen; Sisodiya, Sanjay M.; Tan, Hanno L.; Sander, Josemir W.; Thijs, Roland D.
Abstract
Objectives We ascertained the prevalence of ictal arrhythmias to explain the high rate of sudden unexpected death in epilepsy (SUDEP) in Dravet syndrome (DS). Methods We selected cases with clinical DS, >= 6 years, SCN1A mutation, and >= 1 seizure/week. Home-based ECG recordings were performed for 20 days continuously. Cases were matched for age and sex to two epilepsy controls with no DS and >= 1 major motor seizure during video-EEG. We determined the prevalence of peri-ictal asystole, bradycardia, QTc changes, and effects of convulsive seizures (CS) on heart rate, heart rate variability (HRV), and PR/QRS. Generalized estimating equations were used to account for multiple seizures within subjects, seizure type, and sleep/wakefulness. Results We included 59 cases. Ictal recordings were obtained in 45 cases and compared to 90 controls. We analyzed 547 seizures in DS (300 CS) and 169 in controls (120 CS). No asystole occurred. Postictal bradycardia was more common in controls (n = 11, 6.5%) than cases (n = 4, 0.7%; P = 0.002). Peri-ictal QTc-lengthening (>= 60ms) occurred more frequently in DS (n = 64, 12%) than controls (n = 8, 4.7%, P = 0.048); pathologically prolonged QTc was rare (once in each group). In DS, interictal HRV was lower compared to controls (RMSSD P = 0.029); peri-ictal values did not differ between the groups. Prolonged QRS/PR was rare and more common in controls (QRS: one vs. none; PR: three vs. one). Interpretation We did not identify major arrhythmias in DS which can directly explain high SUDEP rates. Peri-ictal QTc-lengthening was, however, more common in DS. This may reflect unstable repolarization and an increased propensity for arrhythmias.
Association Between IL1B and SCN1A Polymorphism and Febrile Seizures in Children in Siberia
INTERNATIONAL JOURNAL OF BIOMEDICINE
Authors: Stroganova, Maria A.; Dmitrenko, Diana V.; Artyukhov, Ivan P.; Zobova, Svetlana N.; Martynova, Galina P.; Shnayder, Natalia A.; Dyuzhakova, Anna V.
Abstract
Background: Febrile seizures (FS) are a benign, age-dependent, genetically determined state, in which the child's brain is susceptible to epileptic seizures occurring in response to hyperthermia. We assessed whether polymorphisms of IL1B and SCN1A genes, encoding the proinflammatory cytokine IL1B and SCN1A, respectively, could help to predict FS development and find a new way to treat FS. Methods: We examined 121 children with FS and 30 children with hyperthermia syndrome (HTS) aged from 3 to 36 months. SNPs rs1143634 and rs16944 of IL1B gene, and rs3812718 and rs16851603 of SCN1A gene were determined by quantitative real-time PCR. Results: The analysis for rs1143634 revealed an association between the CC genotype and increased risk of FS development (OR 6.56; P=0.0008) against the background of acute respiratory viral infection. The same result was obtained for rs16944 (OR 3.13; P=0.04) and an association of two homozygous genotypes CC/CC. For rs3812718, the carriage of heterozygous genotype CT demonstrated a direct relationship with FS development (OR 44.95; P=0.000). Conclusion: Children with high FS risk need preventive treatment and joint observation of a pediatrician, pediatric infectionist, and a neurologist-epileptologist.