Altered Functional Activation and Network Connectivity Underlies Working Memory Dysfunction in Adolescents with Epilepsy
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University of Cincinnati / OhioLINK
2017
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ndltd-OhioLink-oai-etd.ohiolink.edu-ucin15155142891450942021-08-03T07:05:20Z Altered Functional Activation and Network Connectivity Underlies Working Memory Dysfunction in Adolescents with Epilepsy Radhakrishnan, Rupa, M.D. Surgery Working memory Epilepsy Connectivity Pediatrics Executive function functional MRI Executive dysfunction is observed in adolescents with localization-related and generalized epilepsy, and likely contributes to poor outcomes in social, academic, behavioral and quality of life domains. Identification of neuroimaging biomarkers of brain network connectivity could provide insight into the neural mechanisms of executive dysfunction in epilepsy and facilitate more objective assessment of disruptions in executive function related brain networks. Neural correlates of working memory, a specific component of executive function involving short-term retention and manipulation of information, can be assessed by task based functional MRI (fMRI) studies such as the n-back task. N-back tasks are very demanding and require participants to continually adjust the information held in working memory to incorporate the most recently presented stimulus while simultaneously rejecting or ignoring more temporally distant stimuli. As adolescents with epilepsy are at a greater risk of working memory disability, we hypothesized that fMRI activation in brain regions involved in working memory would be significantly different in children with epilepsy relative to healthy controls and that activation patterns would correlate with neuropsychological measures of executive dysfunction. We performed a prospective case- control study of 29 adolescents with MRI non-lesional epilepsy and 20 healthy controls. Both groups performed standardized measures of executive function and questionnaires (parent and child Behavior Rating Inventory of Executive Function - BRIEF) to rate executive function and behavior. All participants performed an n-back fMRI task with 2-back and 0-back components. We performed group analysis of brain functional activation, ROI based analyses of working memory specific brain regions and functional connectivity analyses of the known working memory networks. Adolescents with epilepsy scored poorly on working memory neuropsycholgical tests Wechsler Intelligence Scale Digit Span, and the working memory composite scores, as well as on the the BRIEF parent report. Analysis of n-back task MRI revealed significantly reduced functional connectivity (p<0.05) between the left frontal operculum to the anterior cingulate gyrus (components of the cingulo-opercular network) in adolescents with epilepsy when compared to controls. There were significant correlations between the Weschler intelligence scale Digit Span scores and activation in the left frontal pole(r =0.53, p=0.013), left frontal operculum/insula (r=0.53, p= 0.015) and left parieto-occipital area(r= 0.48, p= 0.034) in controls, but not in adolescents with epilepsy. In adolescents with epilepsy, there was significant correlation between the activation in the left temporal lobe and parent BRIEF working memory scores(r=0.49, p=0.009). These findings suggest presence of functional reorganization during performance of working memory task. Correlations between brain region activation and specific neuropsychological working memory scores that were significantly worse in adolescents with epilepsy suggests that that the altered pattern of working memory processing in epilepsy patients may be inefficient. 2017 English text University of Cincinnati / OhioLINK http://rave.ohiolink.edu/etdc/view?acc_num=ucin1515514289145094 http://rave.ohiolink.edu/etdc/view?acc_num=ucin1515514289145094 unrestricted This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws. |
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NDLTD |
| language |
English |
| sources |
NDLTD |
| topic |
Surgery Working memory Epilepsy Connectivity Pediatrics Executive function functional MRI |
| spellingShingle |
Surgery Working memory Epilepsy Connectivity Pediatrics Executive function functional MRI Radhakrishnan, Rupa, M.D. Altered Functional Activation and Network Connectivity Underlies Working Memory Dysfunction in Adolescents with Epilepsy |
| author |
Radhakrishnan, Rupa, M.D. |
| author_facet |
Radhakrishnan, Rupa, M.D. |
| author_sort |
Radhakrishnan, Rupa, M.D. |
| title |
Altered Functional Activation and Network Connectivity Underlies Working Memory Dysfunction in Adolescents with Epilepsy |
| title_short |
Altered Functional Activation and Network Connectivity Underlies Working Memory Dysfunction in Adolescents with Epilepsy |
| title_full |
Altered Functional Activation and Network Connectivity Underlies Working Memory Dysfunction in Adolescents with Epilepsy |
| title_fullStr |
Altered Functional Activation and Network Connectivity Underlies Working Memory Dysfunction in Adolescents with Epilepsy |
| title_full_unstemmed |
Altered Functional Activation and Network Connectivity Underlies Working Memory Dysfunction in Adolescents with Epilepsy |
| title_sort |
altered functional activation and network connectivity underlies working memory dysfunction in adolescents with epilepsy |
| publisher |
University of Cincinnati / OhioLINK |
| publishDate |
2017 |
| url |
http://rave.ohiolink.edu/etdc/view?acc_num=ucin1515514289145094 |
| work_keys_str_mv |
AT radhakrishnanrupamd alteredfunctionalactivationandnetworkconnectivityunderliesworkingmemorydysfunctioninadolescentswithepilepsy |
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1719453355500109824 |