1 research outputs found
Quantifying interictal intracranial EEG to predict focal epilepsy
Intracranial EEG (IEEG) is used for 2 main purposes, to determine: (1) if
epileptic networks are amenable to focal treatment and (2) where to intervene.
Currently these questions are answered qualitatively and sometimes differently
across centers. There is a need for objective, standardized methods to guide
surgical decision making and to enable large scale data analysis across centers
and prospective clinical trials.
We analyzed interictal data from 101 patients with drug resistant epilepsy
who underwent presurgical evaluation with IEEG. We chose interictal data
because of its potential to reduce the morbidity and cost associated with ictal
recording. 65 patients had unifocal seizure onset on IEEG, and 36 were
non-focal or multi-focal. We quantified the spatial dispersion of implanted
electrodes and interictal IEEG abnormalities for each patient. We compared
these measures against the 5 Sense Score (5SS), a pre-implant estimate of the
likelihood of focal seizure onset, and assessed their ability to predict the
clinicians choice of therapeutic intervention and the patient outcome.
The spatial dispersion of IEEG electrodes predicted network focality with
precision similar to the 5SS (AUC = 0.67), indicating that electrode placement
accurately reflected pre-implant information. A cross-validated model combining
the 5SS and the spatial dispersion of interictal IEEG abnormalities
significantly improved this prediction (AUC = 0.79; p<0.05). The combined model
predicted ultimate treatment strategy (surgery vs. device) with an AUC of 0.81
and post-surgical outcome at 2 years with an AUC of 0.70. The 5SS, interictal
IEEG, and electrode placement were not correlated and provided complementary
information.
Quantitative, interictal IEEG significantly improved upon pre-implant
estimates of network focality and predicted treatment with precision
approaching that of clinical experts.Comment: 25 pages, 4 Figures, 1 tabl