Developmental outcome of electroencephalographic findings in SYNGAP1 encephalopathy.

SYNGAP1 haploinsufficiency results in a developmental and epileptic encephalopathy (DEE) causing generalized epilepsies accompanied by a spectrum of neurodevelopmental symptoms. Concerning interictal epileptiform discharges (IEDs) in electroencephalograms (EEG), potential biomarkers have been postulated, including changes in background activity, fixation-off sensitivity (FOS) or eye closure sensitivity (ECS). In this study we clinically evaluate a new cohort of 36 SYNGAP1-DEE individuals. Standardized questionnaires were employed to collect clinical, electroencephalographic and genetic data. We investigated electroencephalographic findings, focusing on the cortical distribution of interictal abnormalities and their changes with age. Among the 36 SYNGAP1-DEE cases 18 presented variants in the SYNGAP1 gene that had never been previously reported. The mean age of diagnosis was 8 years and 8 months, ranging from 2 to 17 years, with 55.9% being male. All subjects had global neurodevelopmental/language delay and behavioral abnormalities; 83.3% had moderate to profound intellectual disability (ID), 91.7% displayed autistic traits, 73% experienced sleep disorders and 86.1% suffered from epileptic seizures, mainly eyelid myoclonia with absences (55.3%). A total of 63 VEEGs were revised, observing a worsening of certain EEG findings with increasing age. A disorganized background was observed in all age ranges, yet this was more common among older cases. The main IEDs were bilateral synchronous and asynchronous posterior discharges, accounting for ≥50% in all age ranges. Generalized alterations with maximum amplitude in the anterior region showed as the second most frequent IED (≥15% in all age ranges) and were also more common with increasing age. Finally, diffuse fast activity was much more prevalent in cases with 6 years or older. To the best of our knowledge, this is the first study to analyze EEG features across different age groups, revealing an increase in interictal abnormalities over infancy and adolescence. Our findings suggest that SYNGAP1 haploinsufficiency has complex effects in human brain development, some of which might unravel at different developmental stages. Furthermore, they highlight the potential of baseline EEG to identify candidate biomarkers and the importance of natural history studies to develop specialized therapies and clinical trials.

L-serine treatment in patients with GRIN-related encephalopathy: a phase 2A, non-randomized study.

GRIN-related disorders are rare developmental encephalopathies with variable manifestations and limited therapeutic options. Here, we present the first non-randomized, open-label, single-arm trial (NCT04646447) designed to evaluate the tolerability and efficacy of L-serine in children with GRIN genetic variants leading to loss-of-function. In this phase 2A trial, patients aged 2-18 years with GRIN loss-of-function pathogenic variants received L-serine for 52 weeks. Primary end points included safety and efficacy by measuring changes in the Vineland Adaptive Behavior Scales, Bayley Scales, age-appropriate Wechsler Scales, Gross Motor Function-88, Sleep Disturbance Scale for Children, Pediatric Quality of Life Inventory, Child Behavior Checklist and the Caregiver-Teacher Report Form following 12 months of treatment. Secondary outcomes included seizure frequency and intensity reduction and EEG improvement. Assessments were performed 3 months and 1 day before starting treatment and 1, 3, 6 and 12 months after beginning the supplement. Twenty-four participants were enrolled (13 males/11 females, mean age 9.8 years, SD 4.8), 23 of whom completed the study. Patients had GRIN2B, GRIN1 and GRIN2A variants (12, 6 and 5 cases, respectively). Their clinical phenotypes showed 91% had intellectual disability (61% severe), 83% had behavioural problems, 78% had movement disorders and 58% had epilepsy. Based on the Vineland Adaptive Behavior Composite standard scores, nine children were classified as mildly impaired (cut-off score > 55), whereas 14 were assigned to the clinically severe group. An improvement was detected in the Daily Living Skills domain (P = 0035) from the Vineland Scales within the mild group. Expressive (P = 0.005), Personal (P = 0.003), Community (P = 0.009), Interpersonal (P = 0.005) and Fine Motor (P = 0.031) subdomains improved for the whole cohort, although improvement was mostly found in the mild group. The Growth Scale Values in the Cognitive subdomain of the Bayley-III Scale showed a significant improvement in the severe group (P = 0.016), with a mean increase of 21.6 points. L-serine treatment was associated with significant improvement in the median Gross Motor Function-88 total score (P = 0.002) and the mean Pediatric Quality of Life total score (P = 0.00068), regardless of severity. L-serine normalized the EEG pattern in five children and the frequency of seizures in one clinically affected child. One patient discontinued treatment due to irritability and insomnia. The trial provides evidence that L-serine is a safe treatment for children with GRIN loss-of-function variants, having the potential to improve adaptive behaviour, motor function and quality of life, with a better response to the treatment in mild phenotypes.

Neuropsychiatric comorbidities and cognition in epilepsy with eyelid myoclonia: A retrospective pediatric case series.

OBJECTIVE: Epilepsy with eyelid myoclonia (EEM) is a rare epileptic syndrome classified within the Genetic Generalized Epilepsies of childhood. It is characterized by a high drug resistance, and little is known about prognostic factors and neurodevelopmental comorbidities. The aim of this study was to describe the clinical features, cognitive profile, and prognostic factors in a series of children with EEM. METHODS: This is a retrospective observational study of patients diagnosed with EEM from 2012 to 2022 in a tertiary pediatric hospital. RESULTS: Seventeen patients were analyzed (mean age at symptom onset 5.8 years). Neuropsychiatric comorbidities were present in 76.4% (attention deficit hyperactivity disorder 58.8%, behavioral disorder 11.8%, autism spectrum disorder 11.8%, and psychotic outbreaks 11.8%). Neurocognitive assessment was performed in 75%, revealing cognitive impairment in 66.6% (62.5% with borderline intellectual function and 37.5% with -IQ <70-), with predominant difficulties in executive functions, comprehensive language, and motor skills. Cognitive deterioration was observed in one patient in parallel onset with psychotic symptoms. High refractoriness to antiseizure medication (ASM) was observed, with only 23.5% of the patients being seizure-free after a mean follow-up of 7 years. The most effective ASM was valproic acid, and two of them received ketogenic diet with good response. Regarding prognostic factors, psychotic symptoms were associated with a greater number of antiseizure medication (p < .05) implying a more drug-resistant epilepsy. SIGNIFICANCE: In our study, we found a high rate of cognitive and psychiatric comorbidities and high refractoriness. These data support the concept of EEM as an intermediate entity between idiopathic generalized epilepsy and epileptic and/or neurodevelopmental encephalopathy. Making a proper diagnosis and management of these comorbidities is necessary to improve prognosis and quality of life in EEM.

Outcomes from a Spanish Expanded Access Program on cannabidiol treatment in pediatric and adult patients with epilepsy.

AIM: To evaluate the effectiveness and tolerability of cannabidiol (CBD) in patients with developmental and epileptic encephalopathies, including Dravet syndrome (DS), and Lennox-Gastaut syndrome (LGS), in a Spanish Expanded Access Program (EAP). METHODS: This was a multicenter, retrospective, observational study of patients treated with purified CBD in 14 hospitals across Spain. Patients with (1) written informed consent and (2) at least 6 months follow-up before the closure of the database were included. Primary effectiveness endpoints included reductions (100 %, ≥75 %, ≥50 %, ≥25 %, or 0 %) or worsening in seizure frequency (all seizure types and most disabling seizures) at 1-, 3-, 6-, and 12-month visits and at the last visit, and median relative seizure reduction between baseline and last visit. Secondary effectiveness endpoints included retention rate, reduction in seizure severity, status epilepticus, healthcare utilization, and quality of life. Primary safety endpoints included rates of adverse events (AEs) and AEs leading to discontinuation. RESULTS: One hundred and two patients (DS 12 %; LGS 59 %; other epilepsy syndromes 29 %) with a mean age of 15.9 years were enrolled. Patients were highly refractory to antiseizure medications (ASMs); mean number of prior failed ASMs was 7.5 (SD 3.7). The mean CBD dose was 13.0 mg/kg/day at the last visit. The proportion of patients with ≥50 % reduction in the total number of seizures from baseline was 44.9 % at 6 months and 38.9 % at 12 months. The median number of total seizures per month reduced by 47.6 % from baseline to the last visit. At 12 months, seizure severity was lower in 33/54 patients (61.1 %) and unchanged in 17/54 patients (31.5 %). Quality of life, based on the CAVE scale, increased from a mean score of 17.9 ± 4.7 (n = 54) at baseline to 21.7 ± 5.5 (n = 51) at the last patient visit (21.2 % improvement). The mean treatment retention time was 10.3 months. There were no statistically significant changes in the number of status epilepticus episodes, but lower healthcare utilization was observed. Adverse events occurred in sixty-eight patients (66.7 %), and the most common were somnolence (34.3 %) and diarrhea (12.7 %). Cannabidiol was discontinued exclusively due to AEs in 7.8 % of patients, increasing to 25.5 % when both lack of efficacy and AEs were considered together. CONCLUSIONS: Cannabidiol demonstrated promising effectiveness and tolerability in patients with developmental and epileptic encephalopathies taking part in a Spanish EAP.

Smell and Taste Dysfunction in Pediatric Patients With SARS-CoV-2 Infection.

INTRODUCTION: Anosmia and hypogeusia are frequent symptoms in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in adults, but their incidence in children is unknown. OBJECTIVE: Describe the incidence and associated characteristics of olfactory and gustatory dysfunction in children with SARS-CoV-2 infection. MATERIAL AND METHODS: Descriptive study carried out by telephone survey of patients aged between five and 18 years with SARS-CoV-2 infection confirmed between March and December, 2020. RESULTS: Two hundred eighty Spanish patients (female: 42.2%) with a mean age of 10.4 years (±3.54, range: 5 to 17) were analyzed, 22.5% with other diseases (mostly respiratory: 11.8%). The most frequent symptoms were fever (55.36%) and neurological symptoms (45.7%). Forty-four (15.7%) were hospitalized due to the infection, in intensive care unit (ICU): 7.1%. Forty-five patients (16.1%) had anosmia and/or hypogeusia: 32 both, eight with hypogeusia only, and five with exclusively anosmia. The mean symptom duration in days for anosmia was 36.4, and for hypogeusia it was 27.6. Either symptom was the initial manifestation in 15 patients. None had anosmia/hypogeusia with no other symptoms. Anosmia/hypogeusia was related to the presence of respiratory infection, gastroenteritis, chills, odynophagia, myalgia, asthenia, and anorexia, but not severity (hospitalization/ICU admission). Cohabitation with another infected individual was associated with a higher incidence of anosmia/hypogeusia (P = 0.041) and duration of anosmia (P = 0.006). The presence of anosmia/hypogeusia in cohabitants was associated with longer duration of anosmia (P < 0.001). CONCLUSIONS: The incidence of anosmia/hypogeusia in children with SARS-CoV-2 was lower than that reported in adults, although with a longer duration. Although no association was found between anosmia/hypogeusia and greater disease severity, recognition of these symptoms could help identify paucisymptomatic patients.

Efficacy of Brivaracetam in children with epilepsy.

BACKGROUND AND OBJECTIVES: To determine the efficacy, tolerance, and safety of BRV in children with epilepsy. METHODS: A retrospective study of patients with epilepsy who received treatment with BRV before age 16 years and underwent a minimum follow-up of 3 months. METHOD AND RESULTS: Sixty-six patients were included in the study. Patients received BRV at a mean age of 8.8 years (range 1-16 years). The majority (93.4 %) had refractory epilepsy, 27 with epileptic encephalopathy. The median maximum dose used was 4.3 mg/kg/day. In 30.3 % of the cases, seizure frequency was reduced by over 50 %, and 9 % remained seizure-free. Greater efficacy was observed in those patients who received higher doses and when a direct switch from levetiracetam (LEV) to BRV was performed. The ineffectiveness of LEV was not related to a failure to respond to BRV treatment. Side effects were identified in 24.2 % of the cases, the most frequent being irritability and drowsiness. CONCLUSIONS: BRV appears to be an effective, safe, and well-tolerated AED in children with refractory epilepsy.