6-year course of sleep homeostasis in a case with epilepsy-aphasia spectrum disorder

Nadine Oser; Martina Hubacher; Annette Nageleisen-Weiss; Pieter van Mierlo; Reto Huber; Peter Weber; Bigna K Bölsterli; Alexandre N Datta

doi:10.1016/j.ebr.2021.100488

6-year course of sleep homeostasis in a case with epilepsy-aphasia spectrum disorder

Epilepsy Behav Rep. 2021 Sep 30:16:100488. doi: 10.1016/j.ebr.2021.100488. eCollection 2021.

Authors

Nadine Oser¹, Martina Hubacher¹, Annette Nageleisen-Weiss¹, Pieter van Mierlo^{2

3}, Reto Huber^{4

5

6}, Peter Weber¹, Bigna K Bölsterli⁴, Alexandre N Datta¹

Affiliations

¹ Department of Pediatric Neurology and Developmental Medicine, University of Basel Children's Hospital, Basel, Switzerland.
² Epilog NV, Ghent, Belgium.
³ Medical Image and Signal Processing Group, Ghent University, Belgium.
⁴ Department of Pediatric Neurology and Children's Research Center, University Children's Hospital Zurich, University of Zurich, Switzerland.
⁵ Child Development Center and Children's Research Center, University Children's Hospital Zurich, University of Zurich, Switzerland.
⁶ Department of Child and Adolescent Psychiatry and Psychotherapy, Psychiatric Hospital, University of Zürich, Switzerland.

Abstract

The epilepsy-aphasia spectrum consists of epilepsies with a strong activation of epileptic discharges during non-rapid-eye-movement (NREM) sleep, variable seizure burden and language problems. The homeostatic decrease of slow waves (SW) during NREM sleep (i.e. their amplitude/slope and power) has been related to brain recovery and cognitive function. Epileptic discharges during NREM-sleep were related to an impairment of the decrease of the slope of SW and to cognitive deficits. In this longitudinal case study, we aim to relate this electrophysiological marker, i.e. overnight change of slope of SW, to imaging and behavior. We report a young girl with a fluctuating course in the epilepsy-aphasia spectrum, ranging from the benign end with self-limited childhood epilepsy with centrotemporal spikes (SLECTS) to the severe end with epileptic encephalopathy with continuous spike waves during sleep (CSWS) with two phases of cognitive regression. She was documented over a period of six years including 12 PSGs, six language fMRIs and seven neuropsychological assessments. We longitudinally studied focal and total spike wave index (SWI), detected SW during NREM sleep, calculated their slopes (first and last hour of NREM sleep and overnight change). Deterioration of overnight decrease of the slope of SW was paralleled by the occurrence of the EEG picture of bilateral synchronous electrical status epilepticus during sleep (ESES) and neuropsychological deficits, and this impairment was reversible with resolution of ESES and was accompanied by cognitive improvement. A laterality switch from left to right sided language dominance occurred during recovery from the second regression phase. This might reflect a compensating process. Later, the laterality switched back to the left, possibly facilitated by a low SWI on the left hemisphere. The qualitative analysis of this case supports the view that the longitudinal course of the overnight change of the slope of SW, as an objective, quantitative EEG measure, is related to the course of cognitive function and functional language MR analysis.

Keywords: Benign epilepsy with centro-temporal spikes (BECTS); Electrical status epilepticus during sleep (ESES); Functional magnetic resonance tomography (fMRI); Neuropsychology; Rolandic epilepsy; Self-limited focal epilepsy with centro-temporal spikes (SLECTS); Slow waves.

Publication types

Case Reports