Noninvasive Mapping of Ripple Onset Predicts Outcome in Epilepsy Surgery

Eleonora Tamilia, Margherita A G Matarrese, Georgios Ntolkeras, P Ellen Grant, Joseph R Madsen, Steve M Stufflebeam, Phillip L Pearl, Christos Papadelis
Annals of Neurology 2021 March 12

OBJECTIVE: Intracranial EEG (icEEG) studies show that interictal ripples propagate across the brain of children with medically refractory epilepsy (MRE) and the onset of this propagation (ripple-onset-zone, ROZ) estimates the epileptogenic zone. It is still unknown whether we can map this propagation non-invasively. The goal of this study is to map ripples (ripple-zone, RZ) and their propagation onset (ROZ) using high-density EEG (HD-EEG) and magnetoencephalography (MEG), and to estimate their prognostic value in pediatric epilepsy surgery.

METHODS: We retrospectively analyzed simultaneous HD-EEG and MEG data from 28 children with MRE who underwent icEEG and epilepsy surgery. Using electric and magnetic source imaging, we estimated virtual sensors (VSs) at brain locations that matched the icEEG implantation. We detected ripples on VSs, defined virtual-RZ and virtual-ROZ, and estimated their distance from icEEG. We assessed the predictive value of resecting virtual-RZ and virtual-ROZ for postsurgical outcome. Interictal spike localization on HD-EEG and MEG was also performed and compared with ripples.

RESULTS: We mapped ripple propagation in all patients with HD-EEG and in 27 (96%) patients with MEG. The distance from icEEG did not differ between HD-EEG and MEG when mapping the RZ (26-27 mm; p = 0.6) or ROZ (22-24 mm; p = 0.4). Resecting the virtual-ROZ, but not virtual-RZ or the sources of spikes, was associated with good outcome for HD-EEG (p = 0.016) and MEG (p = 0.047).

INTERPRETATION: HD-EEG and MEG can map interictal ripples and their propagation onset (virtual-ROZ). Mapping non-invasively the ripple onset may augment epilepsy surgery planning and improve surgical outcome of children with MRE. This article is protected by copyright. All rights reserved.

Full Text Links

We have located links that may give you full text access.


You are not logged in. Sign Up or Log In to join the discussion.

Trending Papers

Remove bar
Read by QxMD icon Read

Save your favorite articles in one place with a free QxMD account.


Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"