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 (3D 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
– Management of multimodal data European database
• raw data (e.g. EEG/MRI data)
• meta data (e.g. patient history, seizure
counts, semiological characteristics,
EEG annotations, electrode positions) Coimbra Freiburg
– Multisite access to local databases
Paris
of consortium members
SQL
(data warehouse approach)
• Multiple local databases Client
• Procedures do assure identical data interfaces
content
Grant 211713 EPILEPSIAE 2
Clinical procedures
Consortium consent on Inclusion criteria
• Patient selection (Paris, 2008):
• Criteria for data quality • Patients with focal and multifocal epilepsy
– Standardized annotations • Minimum duration of continuous EEG
recordings: 96h (4 days)
(types and positioning of seizure-
• Minimal number of seizures: 5
related markers: with an interseizure interval of ≥ 3.5h
• 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
change focus identification
• Spikes
• Subclinical events
– Uniform nomenclature of EEG
channels
– EEG review
• Metadata (types and inclusion form)
Grant 211713 EPILEPSIAE 3
T1.1: 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 (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
Grant 211713 EPILEPSIAE 6
Present status
The database is open for collaboration with US-databases
www.epilepsiae.eu