Performance on the N-back task in children with Juvenile Myoclonic Epilepsy: Functional MRI study
Abstract number :
2.463
Submission category :
5. Neuro Imaging / 5B. Functional Imaging
Year :
2022
Submission ID :
2232997
Source :
www.aesnet.org
Presentation date :
12/4/2022 12:00:00 PM
Published date :
Nov 22, 2022, 05:29 AM
Authors :
Vivek Prabhakaran, MD PhD – University of Wisconsin-Madison; Veena A. Nair, PhD – Senior Scientist, Radiology, University Of Wisconsin-Madison; Daniel Chu, BS – University of Wisconsin-Madison; Troy Showers, BS – Neurology – University of Wisconsin-Madison; Liesl Hostetter, BS – Neurology – University of Wisconsin-Madison; Dace Almane, MS – Neurology – University of Wisconsin-Madison; Kevin Dabbs, MS – Neurology – University of Wisconsin-Madison; Nagesh Adluru, PhD – Radiology – University of Wisconsin-Madison; Jana Jones, PhD – Neurology – University of Wisconsin-Madison; Bruce Hermann, PhD – Neurology – University of Wisconsin-Madison; Aaron Struck, MD – Neurology – University of Wisconsin-Madison
This is a Late Breaking abstract
Rationale: Children with JME typically present with broadly average intelligence and by definition are without visually observable structural lesions on MRI. However, disruption in executive functions have been widely reported in this population. Recent evidence suggests that there may be disruptions in cognition-specific neural networks.1 Working memory, a component of executive function, is the ability to temporarily store and manipulate information while performing a range of cognitive tasks. In this prospective on-going study, we examined differences in functional brain activation patterns on the N-back task in a cohort of JME patients compared to healthy controls. The N-back involves monitoring a series of letters and responding whenever the stimulus is presented N trials prior.
Methods: Task-based functional MRI images were acquired in 25 patients with JME and 22 healthy control participants (age 13-25 years) while they performed the ZeroBack (respond to the letter "X") and TwoBack task (respond if the current letter appeared 2 trials prior) in the scanner. Stimuli were presented in blocks of zero-back and two-back alternating with 16-second rest blocks. Each task block consisted of 18 trials, with stimulus duration of 1.2 seconds, and ISI of 800 milliseconds. A high-resolution structural T1-weighted MPRAGE sequence was acquired prior to the fMRI task. SPM12 (developed by Wellcome Trust Centre for Neuroimaging in London, UK) was used for standard preprocessing and statistical analyses. Preprocessing included realignment to the mean functional image, co-registration with the anatomical image (T1-weighted), normalization to the MNI (Montreal Neurological Institute, Montreal, Canada), and spatial smoothing. In the first-level analysis, the conditions of interest corresponding to TwoBack > ZeroBack were modeled. Contrast images were used to evaluate group differences using corrected familywise-error threshold of p-value
Results: There were no significant age (p = 0.12) or sex (p=0.43) differences between the two groups. On the TwoBack vs. Zeroback comparison with healthy controls, patients showed reduced response in the left superior parietal lobule, bilateral angular gyri, bilateral supplementary motor cortex, left precentral gyrus and right middle frontal gyrus.
Conclusions: Early results from this ongoing study indicate that JME patients show disruption in the bilateral parietal, right frontal, and bilateral motor regions on a standard N-back working memory task. These results suggest that fronto-parietal inter-network connections may underlie aspects of the reported executive dysfunction in this cohort and should be investigated further.
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Reference:_x000D_
1. Oyegbile, TO. The role of task-based neural activation research in understanding cognitive deficits in pediatric epilepsy, Epilepsy and Behavior. 2019;99.
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Funding: R01NS111022, 1R01NS123378, R01NS105646, R01NS117568
Neuro Imaging