Does intellectual disability increase sudden unexpected death in epilepsy (SUDEP) risk?

Purpose: An estimated 1.4 million people in the United Kingdom (UK) have intellectual disability (ID) with 210,000 having severe or profound ID. Of these, approximately 125,000 have epilepsy, representing one quarter of all patients with epilepsy in the UK. For those with full scale intellectual quotients (FSIQs) of less than 50, half have epilepsy, with half of these having treatment resistant epilepsy. One of the two major causes of mortality within this population is sudden unexpected death in epilepsy (SUDEP).

Methods: We performed a literature review exploring the extent to which ID was considered as a risk factor for SUDEP. We also considered whether there was any relationship between the types of health care system in which the studies were conducted and whether ID was considered in studies of SUDEP.

Results: We identified 49 studies which had explored risk factors for SUDEP, of which, approximately 50% (n=23) considered ID in the planning stages. Of these studies 60% (n=14) found ID was a risk factor for SUDEP. 60% of all the studies were conducted in countries where the health care system was publicly funded.

Conclusions: Overall we found ID definitions and specified standardized mortality rates and impact of institutionalization to be quite poorly presented.