Grant 211713 EPILEPSIAE 1

• 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 (3D MR data sets)

• Structured metadata (clinical)

• Derived features based on EEG analysis

EUROPEAN EPILEPSY DATABASE

Grant 211713 EPILEPSIAE 2

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

– 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)

– Multisite access to local databases of consortium members (data warehouse approach)

• Multiple local databases• Procedures do assure identical data

content

Coimbra Freiburg

Paris

Replicated European database

Client interfaces

SQL

Grant 211713 EPILEPSIAE 3

Clinical procedures

• Patient selection• Criteria for data quality

– Standardized annotations(types and positioning of seizure-related markers:

• Clinical seizure onset / first behavioural alteration

• EEG seizure onset / first EEG change

• Spikes• Subclinical events

– Uniform nomenclature of EEG channels

– EEG review• Metadata (types and inclusion

form)

Consortium consent on Inclusion criteria (Paris, 2008):

• Patients with focal and multifocal epilepsy• Minimum duration of continuous EEG

recordings: 96h (4 days)• Minimal number of seizures: 5

with an interseizure interval of ≥ 3.5h• Information on subclinical EEG events and

sleep stages in the preictal period• Appropriate electrode implantation for

focus identification

Grant 211713 EPILEPSIAE 4

T1.1: clinical procedures

Sleep staging

EEG onsetEarly propagation

EEG pattern morphology

Grant 211713 EPILEPSIAE 5

Database client interfaces

Coimbra

Freiburg

Paris

Grant 211713 EPILEPSIAE 6

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 (PostgreSQL) 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: > 50Tb

Present status

www.epilepsiae.eu

The database is open for collaboration with US-databases