The Distinct Connectivity Patterns in Human Medial Parietal Cortices: A Cortico-cortical Evoked Potential Study
Abstract number :
1.183
Submission category :
3. Neurophysiology / 3E. Brain Stimulation
Year :
2022
Submission ID :
2204501
Source :
www.aesnet.org
Presentation date :
12/3/2022 12:00:00 PM
Published date :
Nov 22, 2022, 05:25 AM
Authors :
Masaya Togo, MD, PhD – Kobe University; Riki Matsumoto, Professor – Neurology – Kobe University; Kiyohide Usami, assistant professor – Neurology – Kyoto University; Katsuya Kobayashi, Assistant professor – Neurology – Kyoto University; Hirofumi Takeyama, Chief Physician – Neurology – Japanese Red Cross Otsu Hospital; Takuro Nakae, Chief Physician – Neurosurgery – Shiga General Hospital; Akihiro Shimotake, Assistant professor – Neurology – Kyoto University; Takayuki Kikuchi, Lecturer – Neurosurgery – Kyoto University; Kazumichi Yoshida, Associate Professor – Neurosurgery – Kyoto University; Masao Matsuhashi, Associate Professor – Epilepsy, Movement Disorders and Physiology – Kyoto University; Takeharu Kunieda, Professor – Neurosurgery – Ehime University; Ryosuke Takahashi, Professor – Neurology – Kyoto University; Akio Ikeda, Professor – Epilepsy, Movement Disorders and Physiology – Kyoto University
Rationale: The medial parietal cortices are components of the default mode network (DMN), which are active in the resting state. The medial parietal cortices include the precuneus and the dorsal posterior cingulate cortex (dPCC). Few studies have mentioned differences in their connectivity between the two regions, and these differences have not yet been precisely elucidated. Electrophysiological connectivity is essential for understanding cortical function or functional differences. Since little is known about electrophysiological connections from the medial parietal cortices in humans, we evaluated distinct connectivity patterns from the precuneus and dPCC by constructing a standardized connectivity map using cortico-cortical evoked potential (CCEP).
Methods: This study included nine patients with partial epilepsy or a brain tumor who underwent chronic intracranial electrode placement covering the medial parietal cortices. Single-pulse electrical stimuli were delivered to the medial parietal cortices (38 pairs of electrodes). Responses were standardized using the Z-score of the baseline activity, and the connectivity pattern difference between the precuneus and dPCC was investigated using permutation test. A response density map was constructed in the Montreal Neurological Institutes (MNI) space. This electrophysiological connectivity was compared with the published functional connectivity database.
Results: The precuneus tended to connect with the inferior parietal lobule (IPL, the angular gyrus [AG] and the supramarginal gyrus [SMG]), the occipital cortex, superior parietal lobube (SPL), and the dorsal premotor area (PMd) (the 4 most active regions), while the dPCC tended to connect to the middle cingulate cortex, SPL, precuneus, and IPL (AG). The connectivity pattern differs significantly between the precuneus and dPCC stimulation by means of permutation test (p< 0.05). Regarding each part of the medial parietal cortices, the distributions of CCEP responses resembled those of the functional connectivity database.
Neurophysiology