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Objective: Infantile seizures cause great concern for both doctors and parents. In addition to modern neuroimaging and genetics, clinical tools helpful in predicting the course of the disease are needed. We prospectively studied the incidence, electroclinical characteristics and etiologies of epilepsy syndromes with onset before the age of 12 months and looked for prognostic determinants of outcome by age 24 months. Methods: From February 2017 through May 2019, we recruited all eligible infants diagnosed with epilepsy at our unit. Data on electroclinical studies, genetic investigations and drug response were gathered prospectively. The infants were given a structured neurological examination (Hammersmith Infantile Neurological examination [HINE] and Griffiths scales) at predetermined intervals until age 24 months at which age neurocognitive evaluation with Bayley scales was performed. Results: Included were 60 infants (27 female). The mean onset age of epilepsy was 5.3 (±2.5 standard deviation) months. The incidence of epilepsy in the population‐based cohort was 131 (95% confidence interval 99–172)/100 000. Epilepsy syndrome was identified in 80% and etiology in 58% of infants. Self‐limited infantile epilepsy was the second most common syndrome (incidence 18/100 000) after infantile epileptic spasms syndrome. PRRT2 was the most common monogenic cause. At age 24 months, 37% of the infants had drug‐resistant epilepsy (DRE) and half had a global developmental delay (GDD). Abnormal first HINE was the strongest predictor of GDD, followed by DRE and identified etiology. DRE was associated with structural etiology and GDD. Those with normal first HINE and good response to treatment had favorable outcomes, irrespective of the identified etiology. Significance: Our results support a high incidence of self‐limited epilepsy in infancy and PRRT2 as the genetic cause in the first year of life. Notwithstanding the advances in etiological discovery, we want to highlight the importance of clinical evaluation as standardized neurological examination with HINE proved a valuable tool in prognostication. Plain Language Summary: One in every 700–800 babies develop epilepsy within the first year after birth. Our study identified an epilepsy syndrome in 80% and the cause of epilepsy in 60% of the participants. By age 2 years, over one‐third of the children still experienced seizures, and almost half faced significant developmental delay. Structural brain abnormalities increased the likelihood of difficult epilepsy and developmental challenges. Babies whose epilepsy was caused by a gene defect varied widely in development and response to medications. Babies with normal neurological examination at first visit, especially if their seizures stopped quickly, had favorable development. [ABSTRACT FROM AUTHOR]

Aim: To investigate the prevalence of vigabatrin‐attributed visual field defect (VAVFD) in infantile spasms and the utility of optical coherence tomography (OCT) in detecting vigabatrin‐related damage. Method: We examined visual fields by Goldmann or Octopus perimetry and the thickness of peripapillary retinal nerve fiber layer (RNFL) with spectral‐domain OCT at school age or adolescence. Results: Out of 88 patients (38 females, mean age at study 15y, SD 4y 3mo, range 6y 4mo–23y 3mo [n=65] or deceased [n=21] or moved abroad [n=2]) exposed to vigabatrin in infancy, 28 were able to perform formal visual field testing. Two had visual field defect from structural causes. We found mild VAVFD in four patients and severe VAVFD in one patient. Median vigabatrin treatment duration for those with normal visual field was 11 months compared to 19 months for those with VAVFD (p=0.04). OCT showed concomitant attenuated RNFL in three children with VAVFD, and was normal in one. The temporal half of the peripapillary RNFL was significantly thinner in the VAVFD group compared to the normal visual field group. Interpretation: The overall prevalence of VAVFD is lower after exposure in infancy compared to 52% which has been reported after exposure in adulthood. The risk increases with longer treatment duration. Further studies should identify infants particularly susceptible to VAVFD and clarify the role of OCT. [ABSTRACT FROM AUTHOR]

Objective: To profile European trends in pediatric epilepsy surgery (<16 years of age) between 2008 and 2015. Methods: We collected information on volumes and types of surgery, pathology, and seizure outcome from 20 recognized epilepsy surgery reference centers in 10 European countries. Results: We analyzed retrospective aggregate data on 1859 operations. The proportion of surgeries significantly increased over time (P <.0001). Engel class I outcome was achieved in 69.3% of children, with no significant improvement between 2008 and 2015. The proportion of histopathological findings consistent with glial scars significantly increased between the ages of 7 and 16 years (P for trend =.0033), whereas that of the remaining pathologies did not vary across ages. A significant increase in unilobar extratemporal surgeries (P for trend =.0047) and a significant decrease in unilobar temporal surgeries (P for trend =.0030) were observed between 2008 and 2015. Conversely, the proportion of multilobar surgeries and unrevealing magnetic resonance imaging cases remained unchanged. Invasive investigations significantly increased, especially stereo‐electroencephalography. We found different trends comparing centers starting their activity in the 1990s to those whose programs were developed in the past decade. Multivariate analysis revealed a significant variability of the proportion of the different pathologies and surgical approaches across countries, centers, and age groups between 2008 and 2015. Significance: Between 2008 and 2015, we observed a significant increase in the volume of pediatric epilepsy surgeries, stability in the proportion of Engel class I outcomes, and a modest increment in complexity of the procedures. [ABSTRACT FROM AUTHOR]

Byline: Eija. Gaily An important study reporting the results of one-year follow-up in infants of mothers with epilepsy is published in this issue of Neurology India.[1] The authors enrolled 33 [...]

Summary: Objective: Navigated transcranial magnetic stimulation (nTMS) is becoming increasingly popular in noninvasive preoperative language mapping, as its results correlate well enough with those obtained by direct cortical stimulation (DCS) during awake surgery in adult patients with tumor. Reports in the context of epilepsy surgery or extraoperative DCS in adults are, however, sparse, and validation of nTMS with DCS in children is lacking. Furthermore, little is known about the risk of inducing epileptic seizures with nTMS in pediatric epilepsy patients. We provide the largest validation study to date in an epilepsy surgery population. Methods: We compared language mapping with nTMS and extraoperative DCS in 20 epilepsy surgery patients (age range 9‐32 years; 14 children and adolescents). Results: In comparison with DCS, sensitivity of nTMS was 68%, specificity 76%, positive predictive value 27%, and negative predictive value 95%. Age, location of ictal‐onset zone near or within DCS‐mapped language areas or severity of cognitive deficits had no significant effect on these values. None of our patients had seizures during nTMS. Significance: Our study suggests that nTMS language mapping is clinically useful and safe in epilepsy surgery patients, including school‐aged children and patients with extensive cognitive dysfunction. Similar to in tumor surgery, mapping results in the frontal region are most reliable. False negative findings may be slightly more likely in epilepsy than in tumor surgery patients. Mapping results should always be verified by other methods in individual patients. [ABSTRACT FROM AUTHOR]

Objective Population-based studies on infantile epilepsy syndromes are scarce. Our aim was to provide syndrome-specific data on the incidence and outcome of epilepsy in a population-based cohort of infants with epilepsy onset in the first year. Methods Included were all infants born in 1997 through 2006 whose epileptic seizures started before 12 months of age and who were residents of the Helsinki University Hospital district at the time of seizure onset. Patients were ascertained from hospital statistics, and all patient charts were reviewed. A reevaluation of the epilepsy syndromes, age at onset, etiology, and outcome at 24 months of age was based on data abstracted from the patient files. Results Inclusion criteria were fulfilled by 158 infants, of whom 92% were followed until age 24 months or death. The incidence of epilepsy in the first year was 124 of 100,000. An epilepsy syndrome recognized by the revised organization of epilepsies by ILAE was identified in 58% of the patients. The most common syndromes were West syndrome (41/100,000) and benign familial or nonfamilial infantile epilepsy (22/100,000). Etiology was structural-metabolic in 35%, genetic in 17%, and unknown in 48%. Early age at onset was associated with structural-metabolic etiology. Seven infants (4.4%) died before age 2 years. One infant with an SCN2A mutation died of sudden unexplained death in epilepsy ( SUDEP). At 24 months, 58% of all children included in the cohort were seizure-free, and 46% had both seizure freedom and age-appropriate cognitive development. Age at onset was not associated with outcome when etiology was controlled for. Significance Benign familial and nonfamilial infantile epilepsy appears to be more common than previously suggested, second only to West syndrome. Early age at onset is not an independent risk factor for poor outcome. [ABSTRACT FROM AUTHOR]

Abstract: Mutations in the cyclin-dependent kinase-like 5 gene (CDKL5) have been identified in female patients with early onset epileptic encephalopathy and severe mental retardation with a Rett-like phenotype. Subsequently CDKL5 mutations were shown to be associated with more diverse phenotypes including mild epilepsy and autism without epilepsy. Furthermore, CDKL5 mutations were found in patients with Angelman-like phenotype. The severity of epilepsy associated with CDKL5 mutations was recently shown to correlate with the type of CDKL5 mutations and epilepsy was identified to involve three distinct sequential stages. Here, we describe the phenotype of a severe form of neurodevelopmental disease in a female patient with a de novo nonsense mutation of the CDKL5 gene c.175C > T (p.R59X) affecting the catalytic domain of CDKL5 protein. Mutations in the CDKL5 gene are less common in males and can be associated with a genomic deletion as found in our male patient with a deletion of 0.3 Mb at Xp22.13 including the CDKL5 gene. We review phenotypes associated with CDKL5 mutations and examine putative relationships between the clinical epilepsy phenotype and the type of the mutation in the CDKL5 gene. [ABSTRACT FROM AUTHOR]

CO has been long recognized for its anticonvulsant properties. We aimed to determine whether inhaling 5% CO can be used to suppress seizures in epilepsy patients. The effect of CO on cortical epileptic activity accompanying behavioral seizures was studied in rats and nonhuman primates, and based on these data, preliminary tests were carried out in humans. In freely moving rats, cortical afterdischarges paralleled by myoclonic convulsions were evoked by sensorimotor cortex stimulation. Five percent CO was applied for 5 min, 3 min before stimulation. In macaque monkeys, hypercarbia was induced by hypoventilation while seizure activity was electrically or chemically evoked in the sensorimotor cortex. Seven patients with drug-resistant partial epilepsy were examined with video-EEG (electroencephalography) and received 5% CO in medical carbogen shortly after electrographic seizure onset. In rats, 5% CO strongly suppressed cortical afterdischarges, by approximately 75%, whereas responses to single-pulse stimulation were reduced by about 15% only. In macaques, increasing pCO from 37 to 44-45 mm Hg (corresponding to inhalation of 5% CO or less) suppressed stimulation-induced cortical afterdischarges by about 70% and single, bicuculline-induced epileptiform spikes by approximately 25%. In a pilot trial carried out in seven patients, a rapid termination of electrographic seizures was seen despite the fact that the application of 5% CO was started after seizure generalization. Five percent CO has a fast and potent anticonvulsant action. The present data suggest that medical carbogen with 5% CO can be used for acute treatment to suppress seizures in epilepsy patients. [ABSTRACT FROM AUTHOR]

Introduction Prenatal antiepileptic drug (AED) exposure is associated with an increased risk of cognitive impairment and autism spectrum disorders detected mainly at the age of two to six years. We examined whether the developmental aberrations associated with prenatal AED exposure could be detected already in infancy and whether effects on visual attention can be observed at this early age. Material and methods We compared a prospective cohort of infants with in utero exposure to AED (n = 56) with infants without drug exposures (n = 62). The assessments performed at the age of seven months included standardized neurodevelopmental scores (Griffiths Mental Developmental Scale and Hammersmith Infant Neurological Examination) as well as a novel eye-tracking-based test for visual attention and orienting to faces. Background information included prospective collection of AED exposure data, pregnancy outcome, neuropsychological evaluation of the mothers, and information on maternal epilepsy type. Results Carbamazepine, oxcarbazepine, and valproate, but not lamotrigine or levetiracetam, were associated with impaired early language abilities at the age of seven months. The general speed of visuospatial orienting or attentional bias for faces measured by eye-tracker-based tests did not differ between AED-exposed and control infants. Discussion Our findings support the idea that prenatal AED exposure may impair verbal abilities, and this effect may be detected already in infancy. In contrast, the early development of attention to faces was spared after in utero AED exposure. [ABSTRACT FROM AUTHOR]

Research findings concerning cognitive effects of pediatric epilepsy surgery form an important basis for decisions about surgery. However, most follow-up studies have been of limited duration. In this study, a 2-year follow-up of intelligence was undertaken. Risk factors were analyzed. Included were 38 patients aged 3 to 17 years. Surgery was left in 19 patients and right in 19 patients. Types of surgery included temporal lobe resection (n = 23), extratemporal or multilobar resection (n = 8), and hemispherectomy (n = 7). The Wechsler Scales of Intelligence were administered presurgically, 6 months postsurgically, and 2 years postsurgically. No significant change in verbal or performance intelligence quotient (IQ) was demonstrated on a group level. Lateralization, type of surgery, age at surgery, sex, and presurgical IQ did not affect outcome. Across assessments, IQ scores of left-hemisphere patients were lower than those of right-hemisphere patients. Scores of patients in the hemispherectomy group were lower than those of the extratemporal or multilobar resection group, which were lower than the temporal lobe resection group. Scores improved significantly in six patients and deteriorated in seven. In conclusion, epilepsy surgery in children and adolescents does not, in general, have a significant impact on cognitive development in a 2-year perspective. In individual patients, poor seizure control and extensive surgery for Rasmussen’s encephalitis were related to a deterioration of IQ. [Copyright &y& Elsevier]

Prenatal exposure to antiepileptic drugs (AEDs) is associated with developmental compromises in verbal intelligence and social skills in childhood. Our aim was to evaluate whether a multifeature Mismatch Negativity (MMN) paradigm assessing semantic and emotional components of linguistic and emotional processing would be useful to detect possible alterations in early auditory processing of newborns with prenatal AED exposure. Data on AED exposure, pregnancy outcome, neuropsychological evaluation of the mothers, information on maternal epilepsy type, and a structured neurological examination of the newborn were collected prospectively. Blinded to AED exposure, we compared a cohort of 36 AED-exposed with 46 control newborns at the age of two weeks by measuring MMN with a multifeature paradigm with six linguistically relevant deviant sounds and three emotionally uttered sounds. Frontal responses for the emotionally uttered stimulus Happy differed significantly in the exposed newborns compared with the control newborns. In addition, responses to sounds with or without emotional component differed in newborns exposed to multiple AEDs compared with control newborns or to newborns exposed to only one AED. These preliminary findings suggest that prenatal AED exposure may alter early processing of emotionally and linguistically relevant sound information. • Fetal antiepileptic drug exposure may alter early processing of sound information. • Processing of both emotionally and linguistically relevant information is affected. • Present findings might reflect an early precursor of developmental challenge. [ABSTRACT FROM AUTHOR]

Objective: The goal of this study was to assess the complications associated with vertical parasagittal hemispherotomy (VPH), the impact of incomplete disconnection on long-term seizure freedom, and how VPH impacts cognitive development., Methods: A retrospective evaluation was performed in all patients who had undergone VPH during 1991-2022 at the authors' institution. Two-year follow-up data were available for 45 patients, and there were 6-month data for 3 more. All available postoperative MRI studies (31/48, 64.6%) were reviewed. Before 2010, postoperative MRI was only performed if seizures recurred., Results: Primary VPH led to Engel class I in 73% of patients. Acquired etiologies had a higher rate of Engel I compared to developmental and progressive etiologies (96% vs 46% and 44%, p < 0.001). Nearly half of patients (45%) showed improved cognitive trajectories as opposed to their preoperative ones, whereas in 45% trajectories remained unchanged. Additionally, 5 patients (10%) exhibited new major deficits or accelerated cognitive deterioration after VPH. Surgical complications occurred in 14 patients (29%) after the first VPH; 4 cases were classified as transient, resolving during follow-up without surgical intervention. Nontransient complications included 8 cases of hydrocephalus requiring surgical treatment, 1 shunted subdural hygroma, and 1 case of CSF leakage from the wound. Diabetes insipidus occurred in 6 patients, with all resolving spontaneously. Residual connections were present in 16 patients, primarily in the temporomesial region. Seven patients remained seizure free despite visible residual connections., Conclusions: VPH is a highly effective treatment for drug-resistant hemispheric epilepsy, resulting in durable seizure freedom and often favorable cognitive outcomes. Diabetes insipidus in addition to hydrocephalus is a common complication after VPH. Incomplete disconnection does not necessarily preclude seizure freedom.

Background: Sanger sequencing, still the standard technique for genetic testing in most diagnostic laboratories and until recently widely used in research, is gradually being complemented by next-generation sequencing (NGS). No single mutation detection technique is however perfect in identifying all mutations. Therefore, we wondered to what extent inconsistencies between Sanger sequencing and NGS affect the molecular diagnosis of patients. Since mutations in SCN1A, the major gene implicated in epilepsy, are found in the majority of Dravet syndrome (DS) patients, we focused on missed SCN1A mutations., Methods: We sent out a survey to 16 genetic centers performing SCN1A testing., Results: We collected data on 28 mutations initially missed using Sanger sequencing. All patients were falsely reported as SCN1A mutation-negative, both due to technical limitations and human errors., Conclusion: We illustrate the pitfalls of Sanger sequencing and most importantly provide evidence that SCN1A mutations are an even more frequent cause of DS than already anticipated.

The study investigated the nature of the effects of maternal epilepsy on cognitive performance of the offspring. One hundred fifty-four children of mothers with epilepsy aged 5 to 11 years (study group), along with 130 control children, comparable with respect to IQ, socio-economic status, age, and gender underwent a neuropsychological assessment using subtests from the NEPSY: A Developmental Neuropsychological Assessment, tapping attentional, auditory-verbal, visuomotor, fine motor, and memory abilities. The study group scored significantly lower than the controls on measures of attention, memory, and fine-motor function. Deficits were more marked in but not limited to the subset of the study group exposed to maternal medication in utero. Group differences on auditory attention were found only in younger children. Valproate-exposed children obtained lower scores on sentence repetition, as well as on the more demanding part of a test of auditory attention, than other children in the study group, suggesting weaknesses in working memory in the former subgroup. Confounding by maternal epilepsy type and polytherapy complicate interpretation of this finding. Differences between subsets of children not exposed to anti-epileptic drugs in utero and controls suggest that both drug exposure and genetic factors may contribute to cognitive deficits associated with maternal epilepsy.