Epilepsy related multimorbidity, polypharmacy and risks in adults with intellectual disabilities: a national study

Background: A quarter of people with Intellectual Disability (ID) in the UK have epilepsy compared to 0.6% in the general population and die much younger. Epilepsy is associated with two-fifths of all deaths with related polypharmacy and multi-morbidity. Epilepsy research on this population has been poor. This study describes real-world clinical and risk characteristics of a large cohort across England and Wales. Methods: A retrospective multi-centre cohort study was conducted. Information on seizure characteristics, ID severity, relevant co-morbidities, psychotropic and antiseizure drugs (ASDs), SUDEP and other risk factors was collected across a year. Results: Of 904 adults across 10 centres (male:female, 1.5:1), 320 (35%) had mild ID and 584 (65%) moderate-profound (M/P) ID. The mean age was 39.9 years (SD 15.0). Seizures were more frequent in M/P ID (p < 0.001). Over 50% had physical health co-morbidities, more in mild ID (p < 0.01). A third had psychiatric co-morbidity and a fifth had an underlying genetic disorder. Autism Spectrum Disorder was seen in over a third (37%). Participants were on median two ASDs and overall, five medications. Over quarter were on anti-psychotics. Over 90% had an epilepsy review in the past year but 25% did not have an epilepsy care plan, particularly those with mild ID (p < 0.001). Only 61% had a documented discussion of SUDEP, again less likely with mild ID or their care stakeholders (p < 0.001). Conclusions: Significant levels of multi-morbidity, polypharmacy and a lack of systemised approach to treatment and risk exist. Addressing these concerns is essential to reduce premature mortality.