Ketogenic diet improves sleep quality in children with therapy-resistant epilepsy

The study purpose was to evaluate sleep structure during ketogenic diet (KD) treatment in children with therapy-resistant epilepsy and to correlate possible alterations with changes in clinical effects on seizure reduction, seizure severity, quality of life (QOL), and behavior.

Eighteen children were examined with ambulatory polysomnographic recordings initially and after 3 months of KD treatment. Eleven children continued with the KD and were also evaluated after 12 months. Sleep parameters were estimated. Seizure frequency was recorded in a diary and seizure severity in the National Health Seizure Severity Scale (NHS3). QOL was assessed with a visual analogue scale. Child behavior checklist and Ponsford and Kinsella's rating scale of attentional behavior were used.

KD induced a significant decrease in total sleep (p = 0.05) and total night sleep (p = 0.006). Slow wave sleep was preserved, rapid eye movement (REM) sleep increased (p = 0.01), sleep stage 2 decreased (p = 0.004), and sleep stage 1 was unchanged. Eleven children continued with the KD and were also evaluated after 12 months. They showed a significant decrease in daytime sleep (p = 0.01) and a further increase in REM sleep (p = 0.06). Seizure frequency (p = 0.001, p = 0.003), seizure severity (p < 0.001, p = 0.005) and QOL (p < 0.001, p = 0.005) were significantly improved at 3 and 12 months. Attentional behavior was also improved, significantly so at 3 months (p = 0.003). There was a significant correlation between increased REM sleep and improvement in QOL (Spearman r = 0.6, p = 0.01) at 3 months.

KD decreases sleep and improves sleep quality in children with therapy-resistant epilepsy. The improvement in sleep quality, with increased REM sleep, seems to contribute to the improvement in QOL.