Epilepsy syndromes of childhood with sleep activation: Insights from functional imaging

Area of Science:

• Neuroscience
• Pediatric Neurology
• Epileptology

Background:

• Childhood epilepsy syndromes with sleep activation, ranging from benign childhood epilepsy with centrotemporal spikes (BECTS) to epileptic encephalopathy (EE) with continuous spike and waves during slow-wave sleep (CSWS) and Landau-Kleffner syndrome (LKS), exhibit complex functional changes.
• Existing functional imaging studies present inconsistent findings due to varying neuroimaging techniques and clinical phenotype variability.

Purpose of the Study:

• To review and synthesize findings from functional imaging studies in childhood epilepsy syndromes with sleep activation.
• To elucidate the relationship between interictal epileptiform discharges (IEDs), functional brain disturbances, and cognitive impact.

Main Methods:

• Systematic review of functional imaging studies (e.g., PET, fMRI) in pediatric epilepsy syndromes with sleep activation.
• Analysis of regional glucose metabolism, brain activation patterns, and functional connectivity.

Main Results:

• Consistent findings include increased metabolism in epileptogenic zones and decreased metabolism or connectivity in default mode network regions.
• Functional changes can be transient, correlating with IEDs, or permanent.
• More severe phenotypes, such as EE with CSWS, show more pronounced functional disturbances.

Conclusions:

• Functional imaging supports the concept that IEDs negatively impact cognition in these epilepsy syndromes.
• Further research is needed to clarify the temporal relationship between IEDs and functional changes, neuropsychological correlates, and the effects of anti-epileptic treatments.