Abstracts

Rationale: Epilepsy is more common in patients with multiple sclerosis (MS) than the general public. The impact of an epilepsy diagnosis on MS prognosis in terms of mortality and risk of progression to secondary progressive MS (SPMS) has not previously been described. The aim of this study was to investigate the impact of epilepsy on prognosis on a nation-wide scale.  Methods: Data for 15,810 patients in the Swedish MS register was extracted and cross-referenced to the national patient register and the cause of death register until 2014. Cox proportional hazards regression model with time dependent covariates was used for statistical analyses. Results: The hazard ratio of death was increased (HR 4.1, 95%CI: 2.7-6.3) after an epilepsy diagnosis in the entire MS-population, and somewhat higher if only patients with relapsing remitting or secondary progressive MS were included. The hazard ratio for progression to SPMS after an epilepsy diagnosis was not significantly elevated in patients with RRMS.  Conclusions: An epilepsy diagnosis following the diagnosis of MS were associated with a higher risk of death, which at least in part may be explained by epilepsy being more common in severe MS.  Funding: Swedish Society of Medicine, Sahlgrenska University Hospital, Gothenburg Society of Medicine, Felix Neubergh Foundation, Magnus Bergvall Foundation, Jeanssons Foundations