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.

[Epilepsy in children with congenital hemiparesis secondary to perinatal ictus]

The objective was to describe the frequency, mode of presentation and characteristics of epilepsy in children with congenital hemiparesis (CH). It is a etrospective, descriptive and multicenter study, based on the collection of data from the clinical records of patients from 0 to 19 years with CH secondary to perinatal infarction in different centers of the community of Catalonia. A total of 310 children were included (55% males and 45% females), from a total of 13 centers in Catalonia. Average age of onset of the crises was 2 ± 1 year. Epilepsy was present in 29.5% (n = 76), among which the most frequent vascular subtype was arterial presumed perinatal ischemic stroke (51.3%), followed by neonatal arterial ischemic stroke (18.4%), periventricular venous infarction (15.8%), neonatal hemorrhagic stroke (10.5%) and neonatal cerebral sinovenous thrombosis (3.9%). Semiology of the most frequent seizures was motor focal in 82%, followed by focal motor with secondary bilateralization in 23%, focal discognitive in 13.5%, generalized by 2% and spasms in 6.5%. The 67.3% were controlled with monotherapy and the drugs used were valproate, levetiracetam or carbamazepine. The antecedent of electrical status during sleep was identified in 3 patients, all associated with extensive lesions that included the thalamus. Of the total number of children with epilepsy, 35% began with neonatal seizu res in the first 3 days of life. The 30% of children with perinatal stroke and CH present a risk of epilepsy during childhood. Children with ischemic strock have the highest risk, so they will require a follow-up aimed at detecting prematurely the epilepsy and start a treatment.

Macrophytes as potential biomonitors in peri-urban wetlands of the Middle Parana River (Argentina)

The aims of this study were to measure the concentrations of nutrients and pollutants in peri-urban wetlands, to analyze the plant morphology of the most representative macrophyte species, and to determine their potential use as biomonitors. Four wetlands in the Middle Paraná River floodplain evidencing contamination or anthropogenic impact were studied. The studied species were Typha domingensis Pers., Eichhornia crassipes (Mart.) Solms., Alternanthera philoxeroides (Mart.) Griseb., and Pistia stratiotes L. Besides, the same plant species from an uncontaminated wetland considered as control were studied. A. philoxeroides showed the highest total phosphorus (TP) concentration in leaves throughout the study, while the other species showed a higher TP concentration in roots than in leaves. Since metal concentration in A. philoxeroides tissues was always higher than in sediment, further studies focused on its phytoremediation capacity should be carried out. T. domingensis exhibited the highest Zn concentrations in roots followed by Pb, and E. crassipes presented the highest values of Pb concentrations in roots. The aerial part height of the plants from peri-urban wetlands was significantly higher than that of the plants from the control, while the root length was significantly lower. The root length of P. stratiotes showed a negative correlation with soluble reactive phosphorus (SRP) concentration in water. All the root anatomical parameters of T. domingensis and E. crassipes showed a positive correlation with nitrate and ammonium concentrations in water. The studied macrophytes evidenced a high tolerance, enabling them to grow and survive in peri-urban wetlands that receive pollution from different sources. The use of aquatic and wetland plants as contaminant bioindicators and bioaccumulators in the Middle Paraná River floodplain is completely feasible.