Epileptic Encephalopathies with Status Epilepticus during Sleep: New Techniques for Understanding Pathophysiology and Therapeutic Options

Reduced thalamic volume is strongly associated with electrical status epilepticus in sleep

To identify the relationship between thalamic volume and electrical status epilepticus in sleep (ESES). We analyzed subcortical gray matter volumes in patients with an ESES pattern on their electroencephalographs. All magnetic resonance imaging scans were considered within normal limits. The patients were not receiving antiepileptic drug at the time of the MRI study. High resolution T1-weighted 3-dimensional MPRAGE scans were assessed for segmentation and quantitative volumetric analysis of the brain by using the "volBrain" method. After correcting for total brain volume, volumes were compared with a group of healthy controls (HCs) and patients with benign childhood epilepsy with centrotemporal spikes (BECTS). Fifteen patients with ESES, 15 patients with BECTS, and 30 HCs were included. The median age of the patients with ESES was 8.5 (range, 5.8-13) years, 8 (range, 5-14) years for the HCs, and 7.8 (range, 4-13.5) years for the patients with BECTS. The total relative thalamic volume was significantly lower in patients with ESES than in the healthy controls (0.87 ± 0.07 vs. 0.93 ± 0.03, p = 0.002), and in patients with ESES than in those with BECTS (0.87 ± 0.07 vs. 0.93 ± 0.03, p = 0.006). There was no significant difference the HCs and patients with BECTS (0.93 ± 0.03 vs. 0.93 ± 0.03, p = 0.999). Both right and left relative thalamic volumes were lower in patients with ESES than in HCs (right thalamus: 0.43 ± 0.04 vs. 0.46 ± 0.02, p = 0.003, left thalamus: 0.44 ± 0.03 vs. 0.47 ± 0.02, p = 0.002), in patients with ESES than in patients with BECTS (right thalamus: 0.43 ± 0.04 vs. 0.46 ± 0.01, p = 0.01, left thalamus: 0.43 ± 0.04 vs. 0.47 ± 0.01, p = 0.007); however, there was no significant difference between the HCs and patients with BECTS (right thalamus: 0.46 ± 0.02 vs. 0.46 ± 0.01, p = 0.999, left thalamus: 0.47 ± 0.02 vs. 0.47 ± 0.01, p = 0.999). This study highlights the association between thalamic involvement and ESES, even when not severe enough to cause a detectable lesion on visual interpretation of MRI.

Sulthiame add-on treatment in children with epileptic encephalopathy with status epilepticus: an efficacy analysis in etiologic subgroups

PURPOSE

Sulthiame (STM) has been recommended as an effective antiepileptic drug (AED) in children with epileptic encephalopathy with status epilepticus in sleep (ESES). The aim of this study is to evaluate the efficacy of STM add-on treatment in children with pattern of ESES with respect to the etiologic subgroup.

METHODS

Twenty-nine children with ESES pattern with three different etiologic subgroups (epileptic syndromes: 14, structural/infectious: 9, unknown: 6) who were given STM as add-on treatment were included into the study. The efficacy of STM was evaluated in terms of seizure control, electroencephalography (EEG) findings, need of the new AEDs after add-on STM, and behavioral and cognitive improvement.

RESULTS

The range of the follow-up duration after add-on STM treatment was between 5 and 51 months. At the end of 1 year of STM treatment, the most successful electrophysiologic improvement was identified in the well-defined epileptic syndrome group; epileptic syndrome, 71.4% (10/14); structural/infectious, 33.3% (3/9); and unknown, 0% (0/6). Patients who had complete response or persistent ESES pattern at the 3rd month were still in the same condition at the 6th and 12th months. However, the ESES pattern reappeared in 35.2% of the patients who had partial electrophysiological improvement at the 3rd month. In the epilepsy syndrome group, eight out of ten patients who had either complete or partial EEG response after 1 year of STM treatment displayed behavioral and cognitive improvement.

CONCLUSION

Sulthiame might be a valid add-on treatment of ESES especially in children with epilepsy syndromes.

What is more harmful, seizures or epileptic EEG abnormalities? Is there any clinical data?

Cognitive impairment is a common and often devastating co-morbidity of childhood epilepsy. While the aetiology of the epilepsy is a critical determinant of cognitive outcome, there is considerable evidence from both rodent and human studies that indicate that seizures and interictal epileptiform abnormalities can contribute to cognitive impairment. A critical feature of childhood epilepsy is that the seizures and epileptiform activity occur in a brain with developing, plastic neuronal circuits. The consequences of seizures and interictal epileptiform activity in the developing brain differ from similar paroxysmal events occurring in the relatively fixed circuitry of the mature brain. In animals, it is possible to study interictal spikes independently from seizures, and it has been demonstrated that interictal spikes are as detrimental as seizures during brain development. In the clinic, distinguishing the differences between interictal spikes and seizures is more difficult, since both typically occur together. However, both seizures and interictal spikes result in transient cognitive impairment. Recurrent seizures, particularly when frequent, can lead to cognitive regression. While the clinical data linking interictal spikes to persistent cognitive impairment is limited, interictal spikes occurring during the formation and stabilization of neuronal circuits likely contribute to aberrant connectivity. There is insufficient clinical literature to indicate whether interictal spikes are more detrimental than seizures during brain development.

Clinical characteristics and outcome of children with electrical status epilepticus during slow wave sleep

Background:

Electrical status epilepticus in slow wave sleep (ESES) is a rare, age-related, self-limited disorder characterized as epilepsy with different seizure types, neuropsychological impairment in the form of global or selective regression of cognitive functions, motor impairment, and typical electroencephalographic (EEG) findings of continuous epileptic activity occupying 85% of nonrapid eye movement sleep.

Aims:

The aim is to examine the clinical and electrophysiological findings and treatment modalities of children with ESES and to evaluate the outcome of the disorder.

Materials and Methods:

Fourteen patients with a diagnosis of electrical status epilepticus during slow wave sleep and followed-up at least 2 years were included.

Statistical Analysis:

Pearson correlation test was used in the study.

Results:

Among the 14 patients, eight of them had normal mental development before ESES. Twelve of the patients mentioned cognitive impairment and decline in school performance during ESES. After ESES, seven patients had mental retardation in different severity. One of these patients was diagnosed with benign partial epilepsy of childhood with centrotemporal spikes and had normal intelligence quotient level prior to ESES. The diagnosis of ESES was made after newly occurred different seizure types in four of the patients while two of the previously known epileptic patients presented with only severe psychiatric impairment. Valproic acid and carbamazepine were the mostly frequently used drugs before the onset of ESES. After at least 2 years of follow-up, seven patients were seizure free, but still taking antiepileptic treatment. Five patients were seizure free, while two of them had ongoing seizures despite antiepileptic therapy.

Conclusion:

ESES should be kept in mind in children with unexplained regression or stagnation of development associated with seizures or not. Sleep EEGs should be performed for timely diagnosis, proper treatment and prevention of permanent cognitive impairment.

Non-invasive brain stimulation for the treatment of brain diseases in childhood and adolescence: state of the art, current limits and future challenges

In the last decades interest in application of non-invasive brain stimulation for enhancing neural functions is growing continuously. However, the use of such techniques in pediatric populations remains rather limited and mainly confined to the treatment of severe neurological and psychiatric diseases. In this article we provide a complete review of non-invasive brain stimulation studies conducted in pediatric populations. We also provide a brief discussion about the current limitations and future directions in a field of research still very young and full of issues to be explored.

Continuous Spikes and Waves during Sleep: Electroclinical Presentation and Suggestions for Management

Continuous spikes and waves during sleep (CSWS) is an epileptic encephalopathy characterized in most patients by (1) difficult to control seizures, (2) interictal epileptiform activity that becomes prominent during sleep leading to an electroencephalogram (EEG) pattern of electrical status epilepticus in sleep (ESES), and (3) neurocognitive regression. In this paper, we will summarize current epidemiological, clinical, and EEG knowledge on CSWS and will provide suggestions for treatment. CSWS typically presents with seizures around 2-4 years of age. Neurocognitive regression occurs around 5-6 years of age, and it is accompanied by subacute worsening of EEG abnormalities and seizures. At approximately 6-9 years of age, there is a gradual resolution of seizures and EEG abnormalities, but the neurocognitive deficits persist in most patients. The cause of CSWS is unknown, but early developmental lesions play a major role in approximately half of the patients, and genetic associations have recently been described. High-dose benzodiazepines and corticosteroids have been successfully used to treat clinical and electroencephalographic features. Corticosteroids are often reserved for refractory disease because of adverse events. Valproate, ethosuximide, levetiracetam, sulthiame, and lamotrigine have been also used with some success. Epilepsy surgery may be considered in a few selected patients.