Photic Driving Response During Pediatric Stereotactic-EEG Monitoring
Abstract number :
480
Submission category :
3. Neurophysiology / 3C. Other Clinical EEG
Year :
2020
Submission ID :
2422822
Source :
www.aesnet.org
Presentation date :
12/6/2020 5:16:48 PM
Published date :
Nov 21, 2020, 02:24 AM
Authors :
Danielle Brigham, Columbia University Irving Medical Center; Daniel Lowenstein - Columbia University Irving Medical Center;
Rationale:
Intermittent photic stimulation (IPS) is a routine activation procedure used during electroencephalography (EEG) monitoring in attempt to provoke an abnormal electrographic pattern or seizure. A normal physiologic response to IPS is an occipital photic “driving” response, which represents repetitive visual evoked potentials (VEPs) produced in response to the photic flash. Photic driving is a common phenomenon captured on surface electrode EEG recordings, however based our review of the literature, is not commonly observed during stereotactic-EEG (sEEG) monitoring.
Method:
We discuss the case of a 9-year-old female with medically refractory focal epilepsy and left occipital horn heterotopia. On surface EEG, we captured both left and right posterior onset seizures. We implanted her with bilateral sEEG/depth electrodes in attempts to localize her seizure onset zone. Twelve depth electrodes were placed over the left hemisphere and 5 depth electrodes were placed over the right hemisphere. When activation procedures were performed, a photic “driving” response was recorded on sEEG during photic stimulation.
Results:
A photic “driving” response was the most robust at the right temporoparietooccipital junction (RTPOJ) lead, contacts 1-3. A sustained photic “driving” response was seen at all frequencies 3-30 Hz. It was also observed at the left temporoparietooccipital junction (LTPOJ) lead, contacts 1-3 at frequencies 6-8, 11-13, 16, 17, 21, 26, 29, and 30 Hz. The third depth electrode that showed a photic “driving” response was the left superior occipital to the isthmus of the cingulate gyrus (LISTH) lead, contacts 1-2 at frequencies 7, 11, 15-17, and 26 Hz. See attached images for a visual of the photic “driving” response, as well as the location of the depth electrodes.
Conclusion:
Photic “driving” is a common normal finding seen on surface EEG, however it is not reported in the literature to have been seen on sEEG recordings. In our patient, a photic “driving” response was seen in the most mesial leads in 3 depth electrodes. All 3 areas were deep in the occipitoparietal region (RTPOJ and LTPOJ- occipital; LISTH- occipitoparietal junction). To our knowledge, this is the first description of a photic “driving” response seen in a pediatric sEEG recording.
Funding:
:NA
Neurophysiology