AUTHOR=Zhang Ke , Sun Jintao , Sun Yulei , Niu Kai , Wang Pengfei , Wu Caiyun , Chen Qiqi , Wang Xiaoshan 

TITLE=Pretreatment Source Location and Functional Connectivity Network Correlated With Therapy Response in Childhood Absence Epilepsy: A Magnetoencephalography Study

JOURNAL=Frontiers in Neurology

VOLUME=Volume 12 - 2021

YEAR=2021

URL=https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2021.692126

DOI=10.3389/fneur.2021.692126

ISSN=1664-2295

ABSTRACT=Objective: To investigate the differences between antiepileptic drug (AED) responders and nonresponders among patients with childhood absence epilepsy (CAE) using magnetoencephalography (MEG), to additionally evaluate whether the neuromagnetic signals of the brain neurons were correlated with the response to therapy.
Methods: Twenty-four drug-naïve patients were subjected to MEG under six frequency bandwidths during ictal periods. The source location and functional connectivity were analyzed using accumulated source imaging and correlation analysis, respectively. All patients were treated with appropriate AED, at least one year after their MEG recordings, their outcome was assessed and patients were consequently divided into responders and nonresponders.
Results: The source location of the nonresponders was mainly in the frontal cortex at a frequency range of 8-12 Hz and 30-80 Hz, especially 8-12 Hz, while the source location of the responders was mostly in the medial frontal cortex, which was chosen as the region of interest. The nonresponders showed strong positive local frontal connections at 80-250 Hz. 
Conclusions: The frontal cortex and especially the medial frontal cortex might be the critical area associated to nonresponsive AED. The local frontal positive epileptic network in our study was probably due to an abnormal brain growth in CAE patients which could cause nonresponsive AED. One single mechanism cannot explain AED resistance; the nonresponders may represent a subgroup of CAE who is refractory to several antiepileptic drugs.