Abstracts

Different Effects on Interictal Activity with Stimulation on Three Sub-nuclei of the Bilateral Thalamus in a Patient with Bilateral Posterior Temporo-occipito-parietal Drug-resistant Epilepsy

Abstract number : 2.153
Submission category : 4. Clinical Epilepsy / 4C. Clinical Treatments
Year : 2023
Submission ID : 539
Source : www.aesnet.org
Presentation date : 12/3/2023 12:00:00 AM
Published date :

Authors :
Presenting Author: Naoki Ikegaya, MD, PhD – University of Pittsburgh

Thandar Aung, MD, MS – University of Pittsburgh; Ruchi Dhyani, MD – University of Pittsburgh; Arka Mallela, MD – University of Pittsburgh; Arianna Damiani, MS – University of Pittsburgh; Arun Antony, MD – Univesity of Pittsburgh; Hallie Williams, PA – University of Pittsburgh; Jorge Gonzalez-Martinez, MD, PhD – University of Pittsburgh

Rationale:
In patients who aren’t surgical resection candidates, neuromodulation can be the alternative treatment option, including a deep brain stimulator targeting the particular thalamic nucleus. With the thalamus being so intricately connected with cortical regions, thalamic nuclei have been implicated in seizure onset and propagation, and is involved in modulating spontaneous cortical activity. Anterior nucleus has been a potential target, and more recently, the centromedian and pulvinar nucleus have been emerging as potential new targets. In this reported case, we aimed to illustrate the different effects of changes in interictal activities of various cortical structures (lingual gyri and hippocampi) based upon stimulation of different sub-nuclei of thalamus using different stimulation parameters.

Methods:
Bilateral sEEG electrodes were implanted over the bilateral posterior temporo-parieto-occipital cortical regions as well as centromedian, anterior nuclei, and medial and lateral pulvinar sub-nuclei of bilateral thalamus. Stimulations were performed at i) 50Hz, 300us, 4 sec; ii) 100Hz, 300us, 4 sec, and iii) 1Hz, 1000us, 30 sec, and interictal activity 30 and 60 seconds following each stimulation round analyzed. The interictal spikes at (i) lingual gyrus ipsilateral to the stimulation, (ii) lingual gyrus contralateral to the stimulation, and (iii) hippocampus ipsilateral to the stimulation were visually counted after the stimulation effect. The results were compared with the baseline interictal activities on the same day as the stimulation round and between all targets at different stimulation frequencies.

Results:
Various response of interictal activities was noted after the stimulation at different sub-nuclei of the thalamus. Majority of interictal activities reduction (over 50% reduction of spikes) compared to the baseline was noted in the lingual gyrus bilaterally with stimulation of the pulvinar and in hippocampal activities with stimulating the anterior thalamic nucleus. However, the changes at lingual gyrus were rarely noted after the centromedian and anterior nuclei simulation. Difference in the changes in the interictal activities was noted between stimulation of medial and lateral pulvinar nuclei. Also, we noted the changes in the interictal activities were dependent upon the frequency of the stimulation in the medial pulvinar (p < 0.05; Fisher’s exact test).
Clinical Epilepsy