EUROPEAN EPILEPSY DATABASE Aims Implementation of large highquality

EUROPEAN EPILEPSY DATABASE • Aims – Implementation of large, high-quality polymodal data from patients with epilepsy for the purpose of advanced analyses leading to an improved prediction of epileptic seizures • Planned data content • 250 surface, 50 intracranial continuous long-term EEG data sets with annotations • Imaging data (3 D MR data sets) • Structured metadata (clinical) • Derived features based on EEG analysis Grant 211713 EPILEPSIAE 1

Database: preparatory steps • Specific issues: – Safety of personal data • Pseudonymization of patient data • Deletion of data contents with identifying character – Ethical issues • Individual informed patient consent • Restrictions of access and use Replicated European database – Management of multimodal data • raw data (e. g. EEG/MRI data) • meta data (e. g. patient history, seizure counts, semiological characteristics, EEG annotations, electrode positions) Coimbra – Multisite access to local databases of consortium members (data warehouse approach) • Multiple local databases • Procedures do assure identical data content Freiburg Paris SQL Client interfaces Grant 211713 EPILEPSIAE 2

Clinical procedures • • • Consortium consent on Inclusion criteria (Paris, 2008): Patient selection • Patients with focal and multifocal epilepsy Criteria for data quality • Minimum duration of continuous EEG – Standardized annotations recordings: 96 h (4 days) (types and positioning of seizure • Minimal number of seizures: 5 related markers: with an interseizure interval of ≥ 3. 5 h • Clinical seizure onset / first • Information on subclinical EEG events and behavioural alteration sleep stages in the preictal period • EEG seizure onset / first EEG • Appropriate electrode implantation for focus identification change • Spikes • Subclinical events – Uniform nomenclature of EEG channels – EEG review Metadata (types and inclusion form) Grant 211713 EPILEPSIAE 3

T 1. 1: clinical procedures Sleep staging EEG onset Early propagation EEG pattern morphology Grant 211713 EPILEPSIAE 4

Database client interfaces Coimbra Freiburg Paris Grant 211713 EPILEPSIAE 5

Database development Storage of sample values: • External binary files: space efficient & the way people are used to work • Inside database tables: flexible for querying Database system: • Open source (Postgre. SQL) vs. Oracle (commercial) • Decision for Oracle to allow the storage of the samples inside the database Replicated vs. distributed database • Local datatbase at every site, replicated content • Not a single distributed database because of immense data traffic • Estimation of data volume: > 50 Tb Grant 211713 EPILEPSIAE 6

Present status The database is open for collaboration with US-databases www. epilepsiae. eu