Temporal stability of intracranial EEG abnormality maps for localising epileptogenic tissue
Y Wang, GM Schroeder, JJ Horsley… - arXiv preprint arXiv …, 2023 - arxiv.org
arXiv preprint arXiv:2302.05734, 2023•arxiv.org
Objective: Identifying abnormalities in interictal intracranial EEG, by comparing patient data
to a normative map, has shown promise for the localisation of epileptogenic tissue and
prediction of outcome. The approach typically uses short interictal segments of around one
minute. However, the temporal stability of findings has not been established. Methods: Here,
we generated a normative map of iEEG in non-pathological brain tissue from 249 patients.
We computed regional band power abnormalities in a separate cohort of 39 patients for the …
to a normative map, has shown promise for the localisation of epileptogenic tissue and
prediction of outcome. The approach typically uses short interictal segments of around one
minute. However, the temporal stability of findings has not been established. Methods: Here,
we generated a normative map of iEEG in non-pathological brain tissue from 249 patients.
We computed regional band power abnormalities in a separate cohort of 39 patients for the …
Objective
Identifying abnormalities in interictal intracranial EEG, by comparing patient data to a normative map, has shown promise for the localisation of epileptogenic tissue and prediction of outcome. The approach typically uses short interictal segments of around one minute. However, the temporal stability of findings has not been established.
Methods
Here, we generated a normative map of iEEG in non-pathological brain tissue from 249 patients. We computed regional band power abnormalities in a separate cohort of 39 patients for the duration of their monitoring period (0.92-8.62 days of iEEG data, mean 4.58 days per patient, over 4,800 hours recording). To assess the localising value of band power abnormality, we computed DRS - a measure of how different the surgically resected and spared tissue were in terms of band power abnormalities - over time.
Results
In each patient, band power abnormality was relatively consistent over time. The median DRS of the entire recording period separated seizure free (ILAE = 1) and not seizure free (ILAE > 1) patients well (AUC = 0.69). This effect was similar interictally (AUC = 0.69) and peri-ictally (AUC = 0.71).
Significance
Our results suggest that band power abnormality DRS, as a predictor of outcomes from epilepsy surgery, is a relatively robust metric over time. These findings add further support for abnormality mapping of neurophysiology data during presurgical evaluation.
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