Intrinsic Thalamic Network in Temporal Lobe Epilepsy With Hippocampal Sclerosis According to Surgical Outcomes

et al. 2022

J Clin Neurol

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Background and Purpose We aimed to determine 1) the frequency of mammillary body (MB) atrophy in patients with temporal lobe epilepsy (TLE) and hippocampal sclerosis (HS), 2) the clinical significance of MB atrophy, and 3) the association between MB atrophy and volume changes in other subcortical limbic structures. Methods We enrolled 69 patients with pathologically confirmed TLE with HS, who underwent a standard anterior temporal lobectomy, as well as 40 healthy controls. We used the FreeSurfer deep-learning tool of U-Net to obtain the volumes of the subcortical limbic structures, including the MB, hypothalamus, basal forebrain, septal nuclei, fornix, and nucleus accumbens. MB atrophy was considered to be present when the MB volume was decreased relative to the healthy controls. Results MB atrophy was present in 18 (26.1%) of the 69 patients with TLE and HS. Among the clinical characteristics, the mean age at seizure onset was higher (25.5 vs. 15.9 years, p =0.027) and the median duration of epilepsy was shorter (149 vs. 295 months, p =0.003) in patients with than without MB atrophy. The basal forebrain (0.0185% vs. 0.0221%, p =0.004) and septal nuclei (0.0062% vs. 0.0075%, p =0.003) in the ipsilateral hemisphere of HS were smaller in the patients with MB atrophy. Conclusions We observed ipsilateral MB atrophy in about one-quarter of patients with TLE and HS. The severity of subcortical limbic structure abnormalities was greater in patients without MB atrophy. These findings suggest that MB atrophy in TLE with HS is not rare, but it has little clinical significance.

Section: Discussionmentioning

confidence: 99%

Mammillary Body Atrophy in Temporal Lobe Epilepsy With Hippocampal Sclerosis

Cho

et al. 2022

J Clin Neurol

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“…Calculation of intrinsic thalamic network using graph theory and correlation analysis. We previously described the detailed procedure to compute the intrinsic thalamic network using graph theoretical analysis in the BRAPH version 1.0 program [15][16][17]37 . Graph theory was used to analyze the network's nodes and edges.…”

Section: Methodsmentioning

confidence: 99%

Alterations of the thalamic nuclei volumes and intrinsic thalamic network in patients with restless legs syndrome

Park

Kim

et al. 2023

Sci Rep

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We aimed to investigate the alterations of thalamic nuclei volumes and intrinsic thalamic network in patients with primary restless legs syndrome (RLS) compared to healthy controls. Seventy-one patients with primary RLS and 55 healthy controls were recruited. They underwent brain MRI using a three-tesla MRI scanner, including three-dimensional T1-weighted images. The intrinsic thalamic network was determined using graph theoretical analysis. The right and left whole thalamic volumes, and the right pulvinar inferior, left ventral posterolateral, left medial ventral, and left pulvinar inferior nuclei volumes in the patients with RLS were lower than those in healthy controls (0.433 vs. 0.447%, p = 0.034; 0.482 vs. 0.502%, p = 0.016; 0.013 vs. 0.015%, p = 0.031; 0.062 vs. 0.065%, p = 0.035; 0.001 vs. 0.001%, p = 0.034; 0.018 vs. 0.020%, p = 0.043; respectively). There was also a difference in the intrinsic thalamic network between the groups. The assortative coefficient in patients with RLS was higher than that in healthy controls (0.0318 vs. − 0.0358, p = 0.048). We demonstrated the alterations of thalamic nuclei volumes and intrinsic thalamic network in patients with RLS compared to healthy controls. These changes might be related to RLS pathophysiology and suggest the pivotal role of the thalamus in RLS symptoms.

“…We specifically focused on the thalamus in this study because it plays a pivotal role in seizure development, propagation, and termination in patients with focal epilepsy (Chaitanya et al, 2020;Cho et al, 2021;Lee et al, 2020;Park et al, 2019). The thalamus is a relay center for brain signaling, and the connections between different thalamic nuclei and the neocortex have been well demonstrated (Behrens et al, 2003).…”

Section: Patients Withmentioning

confidence: 99%

Brain networks and epilepsy development in patients with Alzheimer disease

Kim

et al. 2023

Brain and Behavior

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IntroductionThis study aimed to investigate the association between brain networks and epilepsy development in patients with Alzheimer disease (AD).MethodsWe enrolled patients newly diagnosed with AD at our hospital who underwent three‐dimensional T1‐weighted magnetic resonance imaging at the time of AD diagnosis and included healthy controls. We obtained the cortical, subcortical, and thalamic nuclei structural volumes using FreeSurfer and applied graph theory to obtain the global brain network and intrinsic thalamic network based on the structural volumes using BRAPH.ResultsWe enrolled 25 and 56 patients with AD with and without epilepsy development, respectively. We also included 45 healthy controls. The global brain network differed between the patients with AD and healthy controls. The local efficiency (2.026 vs. 3.185, p = .048) and mean clustering coefficient (0.449 vs. 1.321, p = .024) were lower, whereas the characteristic path length (0.449 vs. 1.321, p = .048) was higher in patients with AD than in healthy controls. Both global and intrinsic thalamic networks were significantly different between AD patients with and without epilepsy development. In the global brain network, local efficiency (1.340 vs. 2.401, p = .045), mean clustering coefficient (0.314 vs. 0.491, p = .045), average degree (27.442 vs. 41.173, p = .045), and assortative coefficient (−0.041 vs. −0.011, p = .045) were lower, whereas the characteristic path length (2.930 vs. 2.118, p = .045) was higher in patients with AD with epilepsy development than in those without. In the intrinsic thalamic network, the mean clustering coefficient (0.646 vs. 0.460, p = .048) was higher, whereas the characteristic path length (1.645 vs. 2.232, p = .048) was lower in patients with AD with epilepsy development than in those without.ConclusionWe found that the global brain network differs between patients with AD and healthy controls. In addition, we demonstrated significant associations between brain networks (both global brain and intrinsic thalamic networks) and epilepsy development in patients with AD.