Asleep seizures seem to disrupt memory consolidation, according to a pilot study published in Clinical Neurophysiology.
A team from Harvard Medical School recruited 11 people with focal epilepsy aged between 21 and 56 years.
The study participants were asked to complete a memory test, during which they had to remember the positions of 15 pairs of coloured images of animals and everyday objects on a board. The participants were ‘trained’ by being shown where each image was located. They were then asked to remember the locations after either 12 hours of continuous wakefulness, or 12 hours that included sleep.
Memory retention results
After 12 hours of wakefulness, memory retention was found to be 62.7 per cent, which increased to 83.6 per cent when the 12 hours included sleep. The results suggest that sleep enhances memory consolidation in people with epilepsy.
During the study period, three participants had daytime seizures, and three had asleep seizures. Researchers found that, whereas the daytime seizures had no effect on memory, those with nocturnal seizures experienced a drop in memory retention rates.
Significance of findings
The findings of the study are important because they enable scientists to better understand the effect of seizures on memory consolidation. If future, larger studies confirm these results, scientists may be able to develop ways of managing the effects of seizures on sleep-dependent memory function.