Research paper

Intelligence outcomes in 17 patients with developmental and/or epileptic encephalopathy with spike-wave activation in sleep ((D)EE-SWAS) after remission of SWAS

Longitudinal IQ outcomes in 17 (D)EE-SWAS patients after SWAS remission. Mean IQ drop during active phase >20 points. Two post-remission trajectories: partial-recovery group (~half) gained 15.9 IQ points on average; continued-decline group (~half) lost a further 8.1 points on average despite EEG remission. Continued-decline group characterized by significantly earlier age of SWAS onset.

Indexed context

van Arnhem MML, et al.

dee-swasiq-outcomelongitudinalrecovery-trajectoryage-of-onsetprognosis

Markdown path

content/research/papers/2025-van-arnhem-iq-trajectories-post-swas-remission.md

Findings

Why it may matter for Levi

Most relevant published prognostic reference for Levi. Regression began around age 2.5; probable long pre-diagnosis active SWAS period places Levi closer to the earlier-onset risk stratum. Two action priorities: (1) serial formal neuropsychological testing to characterize Levi's actual trajectory rather than relying on developmental progress notes alone; (2) keep electrographic-suppression durability at high priority since the continued-decline group suffered further loss despite EEG remission.

Open PDF or source

Paper text

van Arnhem et al. (2025) — IQ trajectories after SWAS remission

Source

Epilepsy & Behavior, 2025.
URL: https://www.sciencedirect.com/science/article/pii/S1525505025005463

Why this paper is in the corpus

Longitudinal IQ outcome study in 17 children with (D)EE-SWAS after remission of the sleep-activated spike-wave pattern. Identifies two distinct post-remission developmental trajectories — a partial-recovery group and a continued-decline group — and anchors age-of-SWAS-onset as a key determinant of which trajectory a child follows. Same senior-author group as the RESCUE-ESES trial already in the corpus.

Key findings

17 patients with (D)EE-SWAS followed longitudinally after electrographic remission.
Mean IQ drop during the active phase of SWAS exceeded 20 points.
After remission, two trajectories emerged:
- Partial-recovery group (~half): mean IQ increase of 15.9 points post-remission.
- Continued-decline group (~half): mean further IQ decrease of 8.1 points post-remission despite EEG remission.
The continued-decline group was characterized by significantly earlier age of SWAS onset.
Reinforces that earlier onset and longer active-phase duration are the strongest predictors of permanent cognitive impairment.

Levi-relevant takeaways

Most relevant published prognostic reference for Levi's specific situation (recently achieved near-total electrographic resolution; pre-pulse IQ unknown but heavy regression documented).
Levi's age of SWAS onset is uncertain. Active DEE-SWAS was diagnosed March 10, 2026 at age 5.5, but the regression pattern began around age 2.5 years (language use declined) — it is possible that sleep-activated spike-wave was driving regression for well over a year before diagnosis. This places Levi closer to the "earlier onset" risk stratum than a late-onset presentation would.
Supports two decision-relevant priorities:
1. Monitor Levi's post-pulse IQ trajectory with serial formal neuropsychological testing, not just developmental progress notes. The split-trajectory finding means early behavioral gains do not guarantee a partial-recovery outcome.
2. Keep aggressive maintenance / durability of electrographic suppression a high priority — the continued-decline group suffered further decline even after remission, consistent with damage being cumulative during the period of active disease.
Reinforces long-horizon neuropsychological follow-up as a durable priority item.

Citation note

Referenced as [21] in the 2026-04-21 user-supplied comprehensive DEE-SWAS / ESES / CSWS research report. Same senior-author group as RESCUE-ESES (2024-van-den-munckhof-rescue-eses-rct.md).