scholarly journals Evaluation of default mode network in temporal lobe epilepsy patients and healthy subjects: a preliminary result

Author(s):  
JM Shuhada ◽  
MAR Husbani ◽  
A I A Hamid ◽  
AR Muhammad
2020 ◽  
Vol 4 (1) ◽  
pp. 23-30
Author(s):  
Shuhada J.M ◽  
Husbani M.A.R ◽  
A I A Hamid ◽  
Muhammad

The default mode network (DMN) is involved in conscious, resting state cognition and is thought to be affected in TLE where seizures cause impairment of consciousness. The study aimed to evaluate the brain activation of the DMN regions in both temporal lobe epilepsy (TLE) patients  and healthy subjects by using resting-state functional Magnetic Resonance Imaging (rsfMRI) technique. A same number of fourteen participants with age and gender matched for the healthy subjects and TLE patients were selected with the average age is 36.9 and 37.0 years old, respectively. The rsfMRI imaging protocol was executed using a 3-T Phillips Achieva MRI scanner at the Radiology Department, Hospital Universiti Sains Malaysia (HUSM). For healthy subjects, the brain activation cluster in bilateral superior parietal lobes (SPL),precuneus (PRE), supramarginal gyrus (SMG) and inferior parietal lobes (IPL) were found higher than TLE patients. While for TLE patients displays higher activation clusters in bilateral MFG, STG, and ANG. The result from  random effects (RFX) on  two-sample t-tests thresholded at p = 0.001 revealed that the TLE patients display significantly higher activations on the bilateral superior frontal gyrus (SFG), left SMG, left middle frontal gyrus (MFG) and right IPL. However for the core-region of DMN such as  bilateral precuneus, left MFG, bilateral STG and bilateral IPL were significantly activated but the number of voxels survives are substantially smaller than other regions such as bilateral SFG. The findings suggested that TLE patients may suffer from an impairment in some DMN region, which may cause certain neuropsychological and cognitive degradation.       Keywords: resting-state fMRI, temporal lobe epilepsy, brain activation, two-sample t-tests


Medicine ◽  
2018 ◽  
Vol 97 (26) ◽  
pp. e11239 ◽  
Author(s):  
Yujun Gao ◽  
Jinou Zheng ◽  
Yaping Li ◽  
Danni Guo ◽  
Mingli Wang ◽  
...  

Epilepsia ◽  
2013 ◽  
Vol 54 (5) ◽  
pp. 809-818 ◽  
Author(s):  
Cornelia McCormick ◽  
Maher Quraan ◽  
Melanie Cohn ◽  
Taufik A. Valiante ◽  
Mary Pat McAndrews

2012 ◽  
Vol 25 (3) ◽  
pp. 350-357 ◽  
Author(s):  
Zulfi Haneef ◽  
Agatha Lenartowicz ◽  
Hsiang J. Yeh ◽  
Jerome Engel ◽  
John M. Stern

2014 ◽  
Vol 5 ◽  
Author(s):  
Gaelle Eve Doucet ◽  
Christopher Skidmore ◽  
James Evans ◽  
Ashwini Sharan ◽  
Michael R. Sperling ◽  
...  

2020 ◽  
Author(s):  
Elliot G. Neal ◽  
Long Di ◽  
You Jeong Park ◽  
Austin Finch ◽  
Ferdinand Korneli ◽  
...  

AbstractIn patients undergoing surgery for intractable temporal lobe epilepsy, the relationship between the default mode network and patients’ neurocognitive outcome remains unclear. The objective of this study is to employ non-invasive network mapping to identify the relationship between subdivisions of the default mode network and neurocognitive function before and after epilepsy surgery in patients with temporal lobe epilepsy.Twenty-seven medically patients with medically refractory temporal lobe epilepsy were prospectively enrolled and received resting state functional MRI and neuropsychological testing both pre- and post-operatively. Connectivity within the default mode network was modeled and average connectivity within the networks was calculated.Higher pre-operative connectivity in the ventral default mode network hub correlated with impaired baseline performance in a visual memory task. Post-operatively, a decrease in ventral but not dorsal default mode network connectivity was correlated with a deterioration of verbal and logical memory after surgery.Overall, higher connectivity in the ventral default mode network hub was associated with poor memory function in patients with temporal lobe epilepsy both before and after temporal lobe surgery. Pre-operatively, higher ventral connectivity was associated with worse visual function. Post-operatively, decreased connectivity of the ventral and dorsal default mode network was correlated with a greater decrease in logical and verbal memory when compared with the pre-operation baseline. An imbalance in default mode network connectivity towards the ventral stream and more widespread epilepsy networks may be used to predict memory impairments following surgical intervention and may lead to more tailored surgical decision making based on this non-invasive network modeling.


2017 ◽  
Author(s):  
Tamires Araujo Zanão ◽  
Tátila Martins Lopes ◽  
Brunno Machado de Campos ◽  
Mateus Henrique Nogueira ◽  
Clarissa Lin Yasuda ◽  
...  

ABSTRACTObjectiveto investigate abnormal functional connectivity in the resting-state default mode network (DMN) and its relation to memory impairments in patients with temporal lobe epilepsy with and without hippocampal sclerosis (HS)Methodwe enrolled 122 MTLE patients divided into right-HS (n=42), left-HS (n=49), MRI-negative MTLE (n=31) and controls (n=69). All underwent resting-state seed-based connectivity fMRI, with a seed placed at the posterior cingulate cortex, an essential node for the DMN. In addition, patients and 41 controls were tested for verbal and visual memory, estimated intelligence coefficient and delayed recall.ResultsBoth right-HS and MRI-negative group presented the poorest visual memory scores, and right-HS and left-HS had a worse performance in verbal memory compared to controls and MRI-negative groups. As expected, hippocampus was less connected than controls in all groups of patients. Although EEGs indicated that 64.5% of MRI-negative patients were lateralized to the left, this group showed activations similar to the right-HS.ConclusionOur data suggest that there is a disruption of the normal pattern of DMN in MTLE. Patients with left and right-HS presented similar, increased and decreased connectivity in the ipsilateral hemisphere; however, left-HS had abnormal decreased connectivity in the contralateral hemisphere. Per neuropsychological examination, the presence of HS in the left hemisphere had more impact on verbal memory, which was not found when the seizure focus is in the left hemisphere in the absence of HS. The absence of hippocampal atrophy seems to yield a less prominent disruption in both functional connectivity and neuropsychological performance.


2010 ◽  
Vol 32 (6) ◽  
pp. 883-895 ◽  
Author(s):  
Wei Liao ◽  
Zhiqiang Zhang ◽  
Zhengyong Pan ◽  
Dante Mantini ◽  
Jurong Ding ◽  
...  

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