A prospective 5-year longitudinal study detects neurocognitive and imaging correlates of seizure remission in self-limiting Rolandic epilepsy

Increase in EEG functional connectivity and power during wakefulness in self-limited epilepsy with centrotemporal spikes

OBJECTIVE

Examine power and functional connectivity (FC) in children with Self-limited Epilepsy with Centrotemporal Spikes (SeLECTS) during resting-state.

METHODS

We retrospectively analyzed 37 children with SeLECTS and 34 matched controls. Fifty seconds of awake resting-state source-reconstructed EEG per subject were selected to compare groups using power and weighted phase lag index (wPLI). We compared patients' epochs with and without interictal epileptiform discharges (IEDs) between each other and to controls' epochs. Additionally, we compared epochs without IEDs from recent-onset SeLECTS and longer-duration SeLECTS patients between each other and to controls' epochs.

RESULTS

SeLECTS patients demonstrated widespread and significant power increases compared to controls. FC analyses of epochs without IEDs revealed predominantly left-sided increases in the beta band and decreases in theta band compared to controls. In epochs with IEDs, there were further FC increases in the delta band compared to epochs without IEDs located in bilateral fronto-centrotemporal regions. Patients with recent-onset SeLECTS had significant bilateral temporo-parietal FC increases in beta1 relative to controls. Patients with longer-duration SeLECTS showed significant left centrotemporal FC increases in beta and bilateral centrotemporal decreases in delta compared to controls.

CONCLUSIONS

SeLECTS patients exhibit atypical power and FC patterns during wakefulness, even in epochs without IEDs. These were more pronounced in recent-onset cases and epochs with IEDs, suggesting an association between IEDs frequency and the disease course.

SIGNIFICANCE

Studying power and FC abnormalities in children with SeLECTS provides insight into disease evolution and the influence of IEDs on brain networks.

Recognition memory deficits detected through eye-tracking in well-controlled children with self-limited epilepsy with centrotemporal spikes

OBJECTIVE

Children with self-limited epilepsy characterized by centrotemporal spikes (SeLECTS) exhibit cognitive deficits in memory during the active phase, but there is currently a lack of studies and techniques to assess their memory development after well-controlled seizures. In this study, we employed eye-tracking techniques to investigate visual memory and its association with clinical factors and global intellectual ability, aiming to identify potential risk factors by examining encoding and recognition processes.

METHODS

A total of 26 recruited patients diagnosed with SeLECTS who had been seizure-free for at least 2 years, along with 24 control subjects, underwent Wechsler cognitive assessment and an eye-movement-based memory task while video-electroencephalographic (EEG) data were recorded. Fixation and pupil data related to eye movements were utilized to detect distinct memory processes and subsequently to compare the cognitive performance of patients exhibiting different regression patterns on EEG.

RESULTS

The findings revealed persistent impairments in visual memory among children with SeLECTS after being well controlled, primarily observed in the recognition stage rather than the encoding phase. Furthermore, the age at onset, frequency of seizures, and interictal epileptiform discharges exhibited significant correlations with eye movement data.

SIGNIFICANCE

Children with SeLECTS exhibit persistent recognition memory impairment after being well controlled for the disease. Controlling the frequency of seizures and reducing prolonged epileptiform activity may improve memory cognitive development. The application of the eye-tracking technique may provide novel insights into exploring memory cognition as well as underlying mechanisms associated with pediatric epilepsy.

Distinct manifestations and potential mechanisms of seizures due to cortical versus white matter injury in children

PURPOSE

To study seizure manifestations and outcomes in children with cortical versus white matter injury, differences potentially explaining variability of epilepsy in children with cerebral palsy.

METHODS

In this population-based retrospective cohort study, MRIs of children with cerebral palsy due to ischemia or haemorrhage were classified according to presence or absence of cortical injury. MRI findings were then correlated with history of neonatal seizures, seizures during childhood, epilepsy syndromes, and seizure outcomes.

RESULTS

Of 256 children studied, neonatal seizures occurred in 57 and seizures during childhood occurred in 93. Children with neonatal seizures were more likely to develop seizures during childhood, mostly those with cortical injury. Cortical injury was more strongly associated with (1) developing seizures during childhood, (2) more severe epilepsy syndromes (infantile spasms syndrome, focal epilepsy, Lennox-Gastaut syndrome), and (3) less likelihood of reaching > 2 years without seizures at last follow-up, compared to children without cortical injury. Children without cortical injury, mainly those with white matter injury, were less likely to develop neonatal seizures and seizures during childhood, and when they did, epilepsy syndromes were more commonly febrile seizures and self-limited focal epilepsies of childhood, with most achieving > 2 years without seizures at last follow-up. The presence of cortical injury also influenced seizure occurrence, severity, and outcome within the different predominant injury patterns of the MRI Classification System in cerebral palsy, most notably white matter injury.

CONCLUSIONS

Epileptogenesis is understood with cortical injury but not well with white matter injury, the latter potentially related to altered postnatal white matter development or myelination leading to apoptosis, abnormal synaptogenesis or altered thalamic connectivity of cortical neurons. These findings, and the potential mechanisms discussed, likely explain the variability of epilepsy in children with cerebral palsy and epilepsy following early-life brain injury in general.