Abstracts

Rationale: Status epilepticus (SE) is the most serious manifestation of epilepsy. There remains a great deal of uncertainty regarding the optimal treatment, and considerable variability regarding the causes and outcome of status epilepticus. EpiNet has been developed to facilitate investigator-led clinical research in epilepsy. It can be used for registries, pragmatic clinical trials and epidemiological studies. We used the EpiNet platform to conduct a study of status epilepticus in Auckland, New Zealand. Methods: All patients more than 4 weeks old who attended any of the public hospitals or the major private hospital in Auckland (population 1.61 million) between 6 April 2015 and 5 April 2016 following a seizure lasting 10 minutes or longer were identified, and relevant information was recorded in the EpiNet database by three research nurses. Multiple overlapping sources of information were used to identify the patients. Cases were excluded if the status epilepticus commenced outside Auckland, if it occurred in neonates, if there were repeated spasms, even if they lasted more than 10 minutes, or if it followed anoxic brain injury.  Results: More than 6200 presentations to hospital were reviewed by the research nurses. 503 patients who appeared to fulfil  the entry criteria had a total of 640 episodes of apparent status epilepticus, and were entered into the EpiNet database. These records were reviewed by the lead author (PB) or one of the epilepsy fellows (JJ, AB and SS). 473 episodes were accepted as definite or probable status epilepticus and were included in the study; these episodes occurred in 372 patients. 285 (60%) of episodes lasted > 30 minutes, and 188 episodes lasted between 10 and 30 minutes. 52% of patients had a diagnosis of epilepsy before the SE. 59 patients had more than 1 episode of SE during the year, and 13 patients had 4 or more episodes of SE. 58 episodes (12%) developed while the patient was already in hospital. 54% of patients were aged < 15, and 44% of episodes in children were associated with fever. 28 episodes of SE occurred in 22 patients who did not live within the Auckland region.  When these patients were excluded, the incidence of primary and recurrent SE in Auckland was 27.6 episodes (21.7 persons) per 100 000 per year.  If SE is defined as an episode lasting 30 min or longer, (the definition used in many epidemiological studies), the incidence of primary and recurrent SE in Auckland is 16.5 episodes (13.3 persons) per 100 000 per year.16 patients died within 30 days of the episode of SE, giving a 30 day mortality of 4.3%.  Status epilepticus was considered the disease process causing death in only two of the deaths; in all other cases, the SE was a contributing factor but the underlying pathology which caused the SE was considered the primary cause of death. The major pathology causing the deaths was: malignancy (n=4); degenerative disease / dementia (n=3); cerebrovascular disease; subarachnoid haemorrhage; multiple congenital abnormalities; Batten's disease; Aicardi syndrome; acute drug intoxication; recent liver transplant. Conclusions: This study has determined the incidence, aetiology, treatment and outcomes of SE in Auckland, the largest city in New Zealand. Auckland's population is 60% European, 23% Asian, 15% Pacific people, and 11% Maori. The incidence of SE in Auckland is similar to that of other Western countries. The mortality of SE with modern treatment is low. A form has been developed to collect comprehensive data on SE in the on-line EpiNet database, and can be used for local or multicentre cohort studies, and randomized controlled trials. Funding: Health Research Council (New Zealand); Neurological Foundation of New Zealand; Julius Brendel Trust; CSL Biotherapies (NZ) Ltd; Sanofi; Zynerba pharmaceuticals