Abstracts

Rationale: to ato assess the incidence of status epilepticus (SE) using the new definition and classification by the International League Against Epilepsy (ILAE) 2015 in a population based study. The main difference compared to the previous definitions of SE is the introduction of timepoint T1 to establish the diagnosis of status epilepticus. Time T1 depends on the semiological type: it is set at five minutes for generalized/ bilateral tonic clonic status epilepticus, and 10 minutes for focal SE with impaired consciousness. SE episodes were classified as those “with major motor phenomena” (i.e. convulsive) when these occurred either as the only semiology of SE, or as part of a changing semiology including nonconvulsive parts. “SE without major motor phenomena” (nonconvulsive SE, NCSE) was diagnosed if major motor phenomena were absent at any time. NCSE included minor phenomena like subtle perioral or periorbital jerks. Methods: we retrospectively analyzed data from all adult non-hypoxic patients with status epilepticus (SE) admitted to or treated by the Department of Neurology, Christian Doppler Medical Centre, Paracelsus Medical University Salzburg, Austria, between January 2011 and December 2015. Only patients residing in Salzburg City (“census code 50101”, 127.068 adults) were included. The episodes of status epilepticus were defined and classified according to ILAE 2015. Results: 247 patients (age 20 – 99, median 69 years) suffered 297 episodes of SE (including 238 first episodes). The age- and gender-adjusted incidence of first episode was 38.8/100,000 adults per year (95% CI: 28.5 – 51.6, prominent motor phenomena in 59.7%, total in house case fatality 13.4%) (refractory SE: 0.8/ 100,000 adults/ year [95% CI: 0.0 – 5.2], superrefractory 1.3/ 100,000 adults/ year [95% CI: 0.0 – 5.9]). Incidence and mortality increased steadily with patient age. The incidence increased during the study period mainly due to the publication of a new set of diagnostic criteria for NCSE in 2013. The number of SE episodes increased by 10.2 % due to the reduction of the diagnostic time T1 from 30 to 5 minutes. The main etiologies were remote cerebrovascular injury, remote traumatic brain injury, and acute cerebrovascular etiology (acute symptomatic 35 %, remote unprovoked 45 %, progressive disease 14 %, unknown 6 %). History of epilepsy was prevalent in 41.2 %. The onset of SE was witnessed in 45.8 %. SE occurred in hospital in 27.7 %. The mean stay at the neurological intensive care unit was 3.5 days (median 0). First line treatment was mainly lorazepam and rarely midazolam or diazepam. Second line treatment consisted of levetiracetam in the vast majority of cases followed by lacosamide, valproic acid, and phenytoin. Midazolam and propofol were the main anaesthetics used. Ketamine and markedly less frequently cooling, sevoflurane and electro convulsive therapies were used as fourth line therapy. Conclusions: This first population based study with the new definition and classification of SE provides incidence rates of almost the double value of previous studies, with the first time finding of a female predominance. Inhomogeneity in population pyramids over the time, which might explain differences compared to previous studies need to be carefully considered. Funding: none