Alternating hemiplegia of childhood: An electroclinical study of sleep and hemiplegia

PLoS One. 2022 Sep 30;17(9):e0268720. doi: 10.1371/journal.pone.0268720. eCollection 2022.


Objective: Alternating Hemiplegia of Childhood (AHC) is characterised by paroxysmal hemiplegic episodes and seizures. Remission of hemiplegia upon sleep is a clinical diagnostic feature of AHC. We investigated whether: 1) Hemiplegic events are associated with spectral EEG changes 2) Sleep in AHC is associated with clinical or EEG spectral features that may explain its restorative effect.

Methods: We retrospectively performed EEG spectral analysis in five adults with AHC and twelve age-/gender-matched epilepsy controls. Five-minute epochs of hemiplegic episodes and ten-minute epochs of four sleep stages were selected from video-EEGs. Arousals were counted per hour of sleep.

Results: We found 1) hemispheric differences in pre-ictal and ictal spectral power (p = 0.034), during AHC hemiplegic episodes 2) 22% reduced beta power (p = 0.017) and 26% increased delta power (p = 0.025) during wakefulness in AHC versus controls. There were 98% more arousals in the AHC group versus controls (p = 0.0003).

Conclusions: There are hemispheric differences in spectral power preceding hemiplegic episodes in adults with AHC, and sleep is disrupted.

Significance: Spectral EEG changes may be a potential predictive tool for AHC hemiplegic episodes. Significantly disrupted sleep is a feature of AHC.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Electroencephalography*
  • Hemiplegia* / complications
  • Humans
  • Retrospective Studies
  • Sleep Stages
  • Sodium-Potassium-Exchanging ATPase


  • Sodium-Potassium-Exchanging ATPase

Supplementary concepts

  • Alternating hemiplegia of childhood