scholarly journals Network Analysis of the Default Mode Network Using Functional Connectivity MRI in Temporal Lobe Epilepsy

10.3791/51442 ◽  
2014 ◽  
Author(s):  
Zulfi Haneef ◽  
Agatha Lenartowicz ◽  
Hsiang J. Yeh ◽  
Jerome Engel ◽  
John M. Stern
Keyword(s):  
Functional Connectivity ◽  
Network Analysis ◽  
Temporal Lobe Epilepsy ◽  
Temporal Lobe ◽  
Default Mode Network ◽  
Default Mode ◽  
Functional Connectivity Mri

scholarly journals Default Mode Network in Temporal Lobe epilepsy: interactions with memory performance

2017 ◽  
Author(s):  
Tamires Araujo Zanão ◽  
Tátila Martins Lopes ◽  
Brunno Machado de Campos ◽  
Mateus Henrique Nogueira ◽  
Clarissa Lin Yasuda ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Temporal Lobe Epilepsy ◽  
Left Hemisphere ◽  
Temporal Lobe ◽  
Default Mode Network ◽  
Verbal Memory ◽  
Resting State ◽  
Visual Memory ◽  
Hippocampal Sclerosis ◽  
Default Mode

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.

scholarly journals Diminished default mode network recruitment of the hippocampus and parahippocampus in temporal lobe epilepsy

2013 ◽  
Vol 119 (2) ◽  
pp. 288-300 ◽  
Author(s):  
G. Andrew James ◽  
Shanti Prakash Tripathi ◽  
Jeffrey G. Ojemann ◽  
Robert E. Gross ◽  
Daniel L. Drane
Keyword(s):  
Functional Connectivity ◽  
Temporal Lobe Epilepsy ◽  
Temporal Lobe ◽  
Default Mode Network ◽  
Resting State ◽  
Functional Neuroimaging ◽  
Parahippocampal Gyrus ◽  
Epileptogenic Focus ◽  
Data Set ◽  
Default Mode

Object Functional neuroimaging has shown that the brain organizes into several independent networks of spontaneously coactivated regions during wakeful rest (resting state). Previous research has suggested that 1 such network, the default mode network (DMN), shows diminished recruitment of the hippocampus with temporal lobe epilepsy (TLE). This work seeks to elucidate how hippocampal recruitment into the DMN varies by hemisphere of epileptogenic focus. Methods The authors addressed this issue using functional MRI to assess resting-state DMN connectivity in 38 participants (23 control participants, 7 patients with TLE and left-sided epileptogenic foci, and 8 patients with TLE and right-sided foci). Independent component analysis was conducted to identify resting-state brain networks from control participants' data. The DMN was identified and deconstructed into its individual regions of interest (ROIs). The functional connectivity of these ROIs was analyzed both by hemisphere (left vs right) and by laterality to the epileptogenic focus (ipsilateral vs contralateral). Results This attempt to replicate previously published methods with this data set showed that patients with left-sided TLE had reduced connectivity between the posterior cingulate (PCC) and both the left (p = 0.012) and right (p < 0.002) hippocampus, while patients with right-sided TLE showed reduced connectivity between the PCC and right hippocampus (p < 0.004). After recoding ROIs by laterality, significantly diminished functional connectivity was observed between the PCC and hippocampus of both hemispheres (ipsilateral hippocampus, p < 0.001; contralateral hippocampus, p = 0.017) in patients with TLE compared with control participants. Regression analyses showed the reduced DMN recruitment of the ipsilateral hippocampus and parahippocampal gyrus (PHG) to be independent of clinical variables including hippocampal sclerosis, seizure frequency, and duration of illness. The graph theory metric of strength (or mean absolute correlation) showed significantly reduced connectivity of the ipsilateral hippocampus and ipsilateral PHG in patients with TLE compared with controls (hippocampus: p = 0.028; PHG: p = 0.021, after correction for false discovery rate). Finally, these hemispheric asymmetries in strength were observed in patients with TLE that corresponded to hemisphere of epileptogenic focus; 87% of patients with TLE had weaker ipsilateral hippocampus strength (compared with the contralateral hippocampus), and 80% of patients had weaker ipsilateral PHG strength. Conclusions This study demonstrated that recoding brain regions by the laterality to their epileptogenic focus increases the power of statistical approaches for finding interhemispheric differences in brain function. Using this approach, the authors showed TLE to selectively diminish connectivity of the hippocampus and parahippocampus in the hemisphere of the epileptogenic focus. This approach may prove to be a useful method for determining the seizure onset zone with TLE, and could be broadly applied to other neurological disorders with a lateralized onset.

scholarly journals Abnormal default-mode network homogeneity in patients with temporal lobe epilepsy

Medicine ◽  
2018 ◽  
Vol 97 (26) ◽  
pp. e11239 ◽  
Author(s):  
Yujun Gao ◽  
Jinou Zheng ◽  
Yaping Li ◽  
Danni Guo ◽  
Mingli Wang ◽  
...  
Keyword(s):  
Temporal Lobe Epilepsy ◽  
Temporal Lobe ◽  
Default Mode Network ◽  
Default Mode

Default mode network connectivity indicates episodic memory capacity in mesial temporal lobe epilepsy

Epilepsia ◽  
2013 ◽  
Vol 54 (5) ◽  
pp. 809-818 ◽  
Author(s):  
Cornelia McCormick ◽  
Maher Quraan ◽  
Melanie Cohn ◽  
Taufik A. Valiante ◽  
Mary Pat McAndrews
Keyword(s):  
Episodic Memory ◽  
Temporal Lobe Epilepsy ◽  
Temporal Lobe ◽  
Default Mode Network ◽  
Network Connectivity ◽  
Memory Capacity ◽  
Mesial Temporal Lobe Epilepsy ◽  
Default Mode ◽  
Mesial Temporal Lobe

Functional Connectivity MRI Asymmetries in Lateralized Temporal Lobe Epilepsy (P03.112)

Neurology ◽  
2012 ◽  
Vol 78 (Meeting Abstracts 1) ◽  
pp. P03.112-P03.112
Author(s):  
Z. Haneef ◽  
A. Lenartowicz ◽  
H. Yeh ◽  
J. Engel ◽  
J. Stern
Keyword(s):  
Functional Connectivity ◽  
Temporal Lobe Epilepsy ◽  
Temporal Lobe ◽  
Functional Connectivity Mri

scholarly journals Functional Connectivity MRI and Post-Operative Language Performance in Temporal Lobe Epilepsy: Initial Experience

2014 ◽  
Vol 27 (2) ◽  
pp. 158-162 ◽  
Author(s):  
Emanuele Pravatà ◽  
Carlo Sestieri ◽  
Gabriella Colicchio ◽  
Cesare Colosimo ◽  
Gian Luca Romani ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Temporal Lobe Epilepsy ◽  
Temporal Lobe ◽  
Initial Experience ◽  
Language Performance ◽  
Functional Connectivity Mri

scholarly journals Effect of lateralized temporal lobe epilepsy on the default mode network

2012 ◽  
Vol 25 (3) ◽  
pp. 350-357 ◽  
Author(s):  
Zulfi Haneef ◽  
Agatha Lenartowicz ◽  
Hsiang J. Yeh ◽  
Jerome Engel ◽  
John M. Stern
Keyword(s):  
Temporal Lobe Epilepsy ◽  
Temporal Lobe ◽  
Default Mode Network ◽  
Default Mode
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