Clinical and genomic findings in brain heterotopia: Report of a pediatric patient cohort from Romania.

Brain heterotopia is a group of rare malformations with a heterogeneous phenotype, ranging from asymptomatic to a severe clinical picture (drug-resistant epilepsy, severe developmental delay). The etiology is multifactorial, including both genetic and environmental factors. In the present study, a cohort of 15 pediatric patients with brain heterotopia were investigated by clinical examination, electroencephalographic studies, brain imaging, and genomic tests. Most of the patients had epileptic seizures, often difficult to control with one antiepileptic drug; another frequent characteristic in the cohort was developmental delay or intellectual disability, in some cases associated with behavioral problems. The genomic studies revealed an interstitial 22q11.2 microduplication, an anomaly not reported previously in heterotopia patients. Comparing the cohort of the present study with that of a previous series of heterotopia patients, both adult and pediatric, similar aspects, such as the high frequency of drug-resistant epilepsy were observed as well as some differences, such as no systemic malformations and no cases with fatal evolution. The current findings add new data to existing knowledge on a rare heterogeneous disorder. The detailed clinical description, including the epilepsy phenotypes, and genomic profiles bring new insights into a group of disorders, yet to be fully understood.

Trends in pediatric epilepsy surgery in Europe between 2008 and 2015: Country-, center-, and age-specific variation.

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.

Practical clues for diagnosing WWOX encephalopathy.

The WW domain-containing oxidoreductase gene is implicated in autosomal recessive disorders of the central nervous system, expressed either as spinocerebellar ataxia or as a severe form with early-infantile epileptic encephalopathy. Here, we describe the electroclinical evolution of these disorders, adding new diagnostic clues based on a case study. The patient, a boy with early-onset epilepsy, presented with profound global developmental delay, persistent hypsarrhythmia, and epileptic spasms, associated with progressive cerebral atrophy without microcephaly. Metabolic disease was excluded. Whole-exome sequencing showed mutations in the WW domain-containing oxidoreductase gene. Our findings extend the phenotypic traits of this aggressive epileptic encephalopathy, with persistent epileptic spasms and hypsarhythmia as a part of the electroclinical phenotype, demonstrating that microcephaly is not mandatory for diagnosis, even when associated with progressive cerebral atrophy. These mutations might be more frequent than expected among early-onset epileptic encephalopathies. We present practical clues for the diagnosis of WWOX encephalopathy in order to avoid unnecessary investigations and ensure appropriate genetic counselling for the families.

Current use of imaging and electromagnetic source localization procedures in epilepsy surgery centers across Europe.

OBJECTIVE: In 2014 the European Union-funded E-PILEPSY project was launched to improve awareness of, and accessibility to, epilepsy surgery across Europe. We aimed to investigate the current use of neuroimaging, electromagnetic source localization, and imaging postprocessing procedures in participating centers. METHODS: A survey on the clinical use of imaging, electromagnetic source localization, and postprocessing methods in epilepsy surgery candidates was distributed among the 25 centers of the consortium. A descriptive analysis was performed, and results were compared to existing guidelines and recommendations. RESULTS: Response rate was 96%. Standard epilepsy magnetic resonance imaging (MRI) protocols are acquired at 3 Tesla by 15 centers and at 1.5 Tesla by 9 centers. Three centers perform 3T MRI only if indicated. Twenty-six different MRI sequences were reported. Six centers follow all guideline-recommended MRI sequences with the proposed slice orientation and slice thickness or voxel size. Additional sequences are used by 22 centers. MRI postprocessing methods are used in 16 centers. Interictal positron emission tomography (PET) is available in 22 centers; all using 18F-fluorodeoxyglucose (FDG). Seventeen centers perform PET postprocessing. Single-photon emission computed tomography (SPECT) is used by 19 centers, of which 15 perform postprocessing. Four centers perform neither PET nor SPECT in children. Seven centers apply magnetoencephalography (MEG) source localization, and nine apply electroencephalography (EEG) source localization. Fourteen combinations of inverse methods and volume conduction models are used. SIGNIFICANCE: We report a large variation in the presurgical diagnostic workup among epilepsy surgery centers across Europe. This diversity underscores the need for high-quality systematic reviews, evidence-based recommendations, and harmonization of available diagnostic presurgical methods.

Recessive loss-of-function mutations in AP4S1 cause mild fever-sensitive seizures, developmental delay and spastic paraplegia through loss of AP-4 complex assembly.

We report two siblings with infantile onset seizures, severe developmental delay and spastic paraplegia, in whom whole-genome sequencing revealed compound heterozygous mutations in the AP4S1 gene, encoding the σ subunit of the adaptor protein complex 4 (AP-4). The effect of the predicted loss-of-function variants (p.Gln46Profs*9 and p.Arg97*) was further investigated in a patient's fibroblast cell line. We show that the premature stop mutations in AP4S1 result in a reduction of all AP-4 subunits and loss of AP-4 complex assembly. Recruitment of the AP-4 accessory protein tepsin, to the membrane was also abolished. In retrospect, the clinical phenotype in the family is consistent with previous reports of the AP-4 deficiency syndrome. Our study reports the second family with mutations in AP4S1 and describes the first two patients with loss of AP4S1 and seizures. We further discuss seizure phenotypes in reported patients, highlighting that seizures are part of the clinical manifestation of the AP-4 deficiency syndrome. We also hypothesize that endosomal trafficking is a common theme between heritable spastic paraplegia and some inherited epilepsies.

Intellectual disability and epilepsy in down syndrome.

UNLABELLED: Down Syndrome (DS) is the most common genetic cause of mental retardation, with a reported frequency of epilepsy between 1.4-17% (1). There is a paucity of data in the literature regarding epilepsy in Down syndrome and its relation to intellectual disability. OBJECTIVES: The purpose of this article is to analyze the association of epilepsy in children with DS - frequency and type of seizures, treatment, outcome and to compare cognitive impairment of children with DS and epilepsy and DS without epilepsy from our cohort. METHODS: A four years systematic retrospective analysis of the database of the Pediatric Neurology Clinic (January 2010 - December 2013) identified a cohort of 39 pediatric cases with DS and neurological symptoms, 9 of them (23%) associating epileptic seizures. Following data were analysed: clinical and neurological examination, type/s of seizures, electroencephalography (EEG), cerebral magnetic resonance imaging (MRI), psychological examination, psychiatric evaluation in selected cases, electrocardiography (ECG), cardiac ultrasonography, ophthalmologic examination. RESULTS: 23% (9 patients) of the children with DS of our cohort presented epilepsy. Five patients had epileptic spasms (56%), one of these further developed astatic seizures. Focal seizures were observed in three patients (33%) and absence with eyelid myoclonias in one patient (11%). Two of the nine patients with DS and epilepsy had generalized seizures, both with very good response to levetiracetam (LEV). EEG was abnormal at seizure onset, and was improved after treatment. Of the nine children with DS and epilepsy, two (22%) presented mild mental retardation and seven (78%) had moderate to severe cognitive delay. Of the 30 children with DS and without epilepsy, 21 (70%) had mild mental retardation and 9 (30%) had moderate to severe cognitive impairment. CONCLUSIONS: The most frequent epileptic syndrome associated with DS is West syndrome, with good response to specific antiepileptics. All children with DS from our cohort have intelectual disability, more severe in those with epilepsy. Slight improvement of intelectual and language capabilities were seen after seizures control.