Topological alterations in older adults with temporal lobe epilepsy are distinct from amnestic mild cognitive impairment |
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| Authors: | Erik Kaestner Anny Reyes Zhong Irene Wang Daniel L. Drane Vineet Punia Bruce Hermann Robyn M. Busch Carrie R. McDonald for the Alzheimer's Disease Neuroimaging Initiative |
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| Affiliation: | 1. Center for Multimodal Imaging and Genetics, University of California, San Diego, San Diego, CA, USA;2. Epilepsy Center, Neurological Institute, Cleveland Clinic, Cleveland, OH, USA;3. Departments of Neurology and Pediatrics, Emory University School of Medicine, Atlanta, GA, USA;4. Department of Neurology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA;5. Data used in the preparation of this article were obtained from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database (adni.loni.usc.edu). As such, the investigators within the ADNI contributed to the design and implementation of ADNI and/or provided data but did not participate in the analysis or writing of this report. A complete listing of ADNI investigators can be found at http://adni.loni.usc.edu/wp-content/uploads/how_to_apply/ADNI_Acknowledgement_List.pdf. |
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| Abstract: | Epilepsy incidence and prevalence peaks in older adults, yet systematic studies of brain aging and epilepsy remain limited. We investigated topological network disruption in older adults with temporal lobe epilepsy (TLE; age > 55 years). Additionally, we examined the potential network disruption overlap between TLE and amnestic mild cognitive impairment (aMCI), the prodromal stage of Alzheimer disease. Measures of network integration (“global path efficiency”) and segregation (“transitivity” and “modularity”) were calculated from cortical thickness covariance from 73 TLE subjects, 79 aMCI subjects, and 70 healthy controls. Compared to controls, TLE patients demonstrated abnormal measures of segregation (increased transitivity and decreased modularity) and integration (decreased global path efficiency). aMCI patients also displayed increased transitivity and decreased global path efficiency, but these differences were less pronounced than in TLE. At the local level, TLE patients demonstrated decreased local path efficiency focused in the bilateral temporal lobes, whereas aMCI patients had a more frontal-parietal distribution. These results suggest that network disruption at the global and local level is present in both disorders, but global disruption may be a particularly salient feature in older adults with TLE. These findings motivate further research into whether these network changes have distinct cognitive correlates or are progressive in older adults with epilepsy. |
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| Keywords: | amnestic mild cognitive impairment graph theory older adults temporal lobe epilepsy |
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