Long term outcome in children affected by absence epilepsy with onset before the age of three years

Early onset absence epilepsy of childhood: Epidemiologic data, treatment and outcome in a sample of 56 patients born between 2000 and 2018

PURPOSE

The aim of our work is to describe the characteristics of Early Onset Absence Epilepsy (EOAE) and to observe whether specific anamnestic, clinical or electroencephalographic characteristics can influence the drug sensitivity of this pathology.

METHODS

We carried out a retrospective study of patients affected by absence epilepsy with onset under four years of age, born between January 1st 2000 and December 31st 2018, who were reffered to the Regional Epilepsy Center of Spedali Civili of Brescia. We then divided the sample into three groups based on the age of onset.

RESULTS

Our sample is composed of 56 patients. Among the children with epilepsy onset under two years of age (11), all were still on therapy after three and six years of follow-up, and 64 % of them required polytherapy. Among patients with epilepsy onset between two and three years of age (24), 87 % were still on therapy after three years of follow-up and 68 % after six years of follow-up; 46 % of these subjects required polytherapy. Among patients with epilepsy onset between three and four years of age (21), 89 % were still on therapy after three years of follow-up and 38 % after six years of follow-up; 38 % of them required polytherapy.

CONCLUSIONS

We observe that patients with an earlier epilepsy onset have a worse outcome and a lower drug sensitivity. This may allow to predict in which cases it would be appropriate to maintain antiseizure therapy for a prolonged period.

Language measurement in childhood epilepsy: A review

The psychosocial well-being of children and adolescents with epilepsy is affected by comorbid language deficits. Little is known about the focus of current research in language and epilepsy. A systematic review of research was conducted to identify gaps in knowledge regarding language and epilepsy. In total, 83 published articles were eligible for inclusion. More studies included samples presenting with focal seizures (k = 39) compared to generalized seizures (k = 10), few included measures of morphology (k = 4). Most studies (k = 66) included samples of participants across a wide age range. Our review indicated t-hat future research should include a greater focus on participants with more diversity in epilepsy etiology (e.g., symptomatic epilepsy), and seizure type (e.g., generalized seizures), assessment of additional areas of language (e.g., morphology), increased focus on early childhood, focused examination of specific developmental stages, and greater use of comparison groups with an alternate epilepsy diagnosis.

Language in childhood epilepsy: A systematic review and meta-analysis

The abnormal brain activity associated with childhood epilepsy can have an impact on the developmental trajectory of cognitive processes, like language, in this population. However, there is variation in how researchers study language ability in children with epilepsy and the findings that are reported (no differences vs. a significant difference). The current systematic review and meta-analysis uses data from 13 available studies to consider the magnitude of language differences in children with epilepsy compared to their typically developing peers. Seizure classification, age of onset, component of language measured, and instrument used to measure language were all considered as potential moderators of differences in language skill. The results indicate a significant large effect size for language deficits in children with epilepsy compared to their peers. Seizure classification partially, but not fully, accounts for the variability in effect size. In addition, effect sizes differ relative to component of language measured; effect sizes were greatest in magnitude for semantic language and verbal fluency, and minimal for syntax, but only when including all studies of children with epilepsy, regardless of seizure classification. These findings differ when considering language component in children with generalized or focal seizures only. The data reported here also indicate distinct differences in effect size depending on type of instrument used to measure one aspect of language, verbal fluency.

Absence Seizures in Children: Usual and the Unusual

Absence seizures are commonly encountered in clinical practice. The diagnosis is usually straightforward in majority of cases. However, it may be challenging in patients with some atypical clinical or EEG features or less common epilepsy syndromes. This narrative review describes the clinical and EEG features, treatment and prognosis of the usual and the unusual epilepsy syndromes associated with absence seizures. Absence status epilepticus is also discussed briefly.

Towards a Better Understanding of Cognitive Deficits in Absence Epilepsy: a Systematic Review and Meta-Analysis

Cognition in absence epilepsy (AE) is generally considered undisturbed. However, reports on cognitive deficits in AE in recent years have suggested otherwise. This review systematically assesses current literature on cognitive performance in children with AE. A systematic literature search was performed in Pubmed, Embase, Cochrane and Web of Science. All studies reporting on cognitive performance in children with AE were considered. In total 33 studies were eligible for inclusion. Neuropsychological tests were classified into the following domains: intelligence; executive function; attention; language; motor & sensory-perceptual examinations; visuoperceptual/visuospatial/visuoconstructional function; memory and learning; achievement. Random-effect meta-analyses were conducted by estimating the pooled mean and/or pooling the mean difference in case-control studies. Full-scale IQ in children with AE was estimated at 96.78 (95%CI:94.46–99.10) across all available studies and in case-control studies IQ was on average 8.03 (95%CI:-10.45- -5.61) lower. Verbal IQ was estimated at 97.98 (95%CI:95.80–100.16) for all studies and 9.01 (95%CI:12.11- -5.90) points lower in case-control studies. Performance IQ was estimated at 97.23 (93.24–101.22) for all available studies and 5.32 (95%CI:-8.27–2.36) points lower in case-control studies. Lower performance was most often reported in executive function (cognitive flexibility, planning, and verbal fluency) and attention (sustained, selective and divided attention). Reports on school difficulties, neurodevelopmental problems, and attentional problems were high. In conclusion, in contrast to common beliefs, lower than average neurocognitive performance was noted in multiple cognitive domains, which may influence academic and psychosocial development.

Early clinical and EEG findings associated with the outcome in childhood absence epilepsy

OBJECTIVES

The objective of this study was to investigate several clinical electroencephalogram (EEG) findings possibly predicting the early response to antiepileptic drugs (AEDs) and the late outcome in children with clinical EEG features fitting the syndromic diagnosis of childhood absence epilepsy (CAE).

METHODS

In 117 untreated patients with typical absences, we analyzed clinical EEG features, and resting EEG activity using partial directed coherence to calculate out- and inflow of cortical oscillations in different regions of interest.

RESULTS

Absences began before 4 years in 12.0%, at 4-9.5 years in 71.8%, and at 10-13 years in 16.2% of the cases. Valproate was started in 91 patients and ethosuximide in 27. With one of AEDs, 77.8% reached seizure control, while the remaining patients needed to switch to the alternative AED. Only 5.9% patients remained drug-resistant. Absences with simple automatisms were the only feature associated with a lack of response to the first AED. Connectivity analysis of resting EEGs showed increased frontal outflow in patients compared with controls, which was significantly greater in the nonresponders to the first AED than in responders. Among the 91 patients followed for 61.2 ± 31.7 months, 14.2% relapsed after a seizure-free period, without differences between the responders to the first or second AED.

CONCLUSIONS

The assessment of electroclinical features provided only minimal prognostic indices. The enhanced outflow of frontal oscillations suggests a circuitry dysfunction significantly greater in the nonresponder to the early treatment. Seizure relapses were rare and comparable in patients who reached seizure freedom with first or second AED, indicating that the resistance to one AED does not influence the outcome.

Glut1 deficiency: when to suspect and how to diagnose?

Impaired glucose transport across the blood-brain barrier results in GLUT1 deficiency syndrome (GLUT1-DS), characterized by infantile seizures, developmental delay, acquired microcephaly, spasticity, ataxia, and hypoglycorrhachia. A part from this classic phenotype, clinical conditions associated with a deficiency of GLUT1 are highly variable and several atypical variants have been described; in particular, patients with movement disorders, but without seizures, with paroxysmal exertion-induced dyskinesia, have been reported. Most patients carry heterozygous de novo mutations in the GLUT1-gene but autosomal dominant and recessive transmission has been identified. Diagnosis is based on low cerebrospinal fluid glucose, in the absence of hypoglycemia, and it is confirmed by molecular analysis of the GLUT1-gene and by glucose uptake studies and immunoreactivity in human erythrocytes. Treatment with a ketogenic diet results in marked improvement of seizures and movement disorders. This review summarizes recent advances in understanding of GLUT1-DS and highlights the diagnostic and therapeutic approach to GLUT1-DS.

"Electro-clinical syndromes" with onset in paediatric age: the highlights of the clinical-EEG, genetic and therapeutic advances

The genetic causes underlying epilepsy remain largely unknown, and the impact of available genetic data on the nosology of epilepsy is still limited. Thus, at present, classification of epileptic disorders should be mainly based on electroclinical features. Electro-clinical syndrome is a term used to identify a group of clinical entities showing a cluster of electro-clinical characteristics, with signs and symptoms that together define a distinctive, recognizable, clinical disorder. These often become the focus of treatment trials as well as of genetic, neuropsychological, and neuroimaging investigations. They are distinctive disorders identifiable on the basis of a typical age onset, specific EEG characteristics, seizure types, and often other features which, when taken together, permit a specific diagnosis which, in turn, often has implications for treatment, management, and prognosis. Each electro-clinical syndrome can be classified according to age at onset, cognitive and developmental antecedents and consequences, motor and sensory examinations, EEG features, provoking or triggering factors, and patterns of seizure occurrence with respect to sleep. Therefore, according to the age at onset, here we review the more frequently observed paediatric electro-clinical syndrome from their clinical-EEG, genetic and therapeutic point of views.

Early-onset pure absence epilepsy: a distinct epileptic syndrome

Early-onset pure absence epilepsy has not yet considered in the International League Against Epilepsy classification, but several reports have supported its existence as a distinct epileptic syndrome primarily manifesting with typical absences in early childhood. This review summarizes the current understanding on this epilepsy.

CONCLUSIONS

  Early-onset pure absence epilepsy is a distinct epilepsy characterized by absences starting from a few months to 4 years of age, normal early psychomotor development, good antiepileptic drug seizure control and normal intellectual outcome.