Prone sleeping and SUDEP risk: The dynamics of body positions in nonfatal convulsive seizures.

BACKGROUND: Most victims of sudden unexpected death in epilepsy (SUDEP) are found prone with signs suggestive of an unwitnessed convulsive seizure (CS). Prone sleeping has been proposed as a risk factor for SUDEP. Little is known, however, about the change of body position during the course of CSs.

METHODS: We retrospectively reviewed video-EEG data and assessed body positions during the course of CSs, until there was a physical interaction by nursing staff with the subject.

RESULTS: We identified 180 CSs in 90 individuals. In 16 of the 180 CSs (9%), the subject started in or turned to the prone position. Of the seven CSs that started in the prone position, three turned to a lateral position during the CS. In 13 CSs, the subject was in prone position at time of nursing intervention; nine (69%) of these started in a nonprone position.

DISCUSSION: Our data suggest that the prone position occurs infrequently in closely supervised nonfatal CSs, a notable contrast to the number of victims of SUDEP found prone. Whether prone sleeping prior to CSs increases SUDEP risk, however, remains speculative, as body position during the course of a CS appeared to be dynamic.