Cognitive Phenotyping and Global Efficiency in Temporal Lobe Epilepsy
Abstract number :
2.203
Submission category :
5. Neuro Imaging / 5A. Structural Imaging
Year :
2023
Submission ID :
643
Source :
www.aesnet.org
Presentation date :
12/3/2023 12:00:00 AM
Published date :
Authors :
Presenting Author: Rebecca Roth, BA – Emory University
Allen Chang, PhD – Medical University of South Carolina; Ruxue Gong, PhD – Emory University; Leonardo Bonilha, MD, PhD – leonardo.bonilha@emory.edu; Daniel Drane, PhD – Emory University; Ezequiel Gleichgerrcht, MD, PhD – Emory University
Rationale: Temporal Lobe Epilepsy (TLE) is the most common form of focal epilepsy, and commonly associated with cognitive deficits, including memory, language, and executive functioning. Cognitive impairments can be a result of duration of epilepsy, medication effects, or frequency, location, and spread of seizures. These factors result in differential types of cognitive dysfunction, which has recently led to the systematic classification of neuropsychological profiles or phenotypes of cognitive dysfunction.
Methods: Sixty-two patients with left (n=25) or right (n=37) drug-resistant TLE underwent both MRI and neuropsychological examination on the following battery: the Rey Auditory Verbal Learning Test (AVLT) and Logical Memory (taken from WAIS-IV) for verbal memory, Digit Span and the Wisconsin Card Sorting Test (WCST) for executive functioning, and the Boston Naming Test (BNT) and Columbia Auditory Naming Test (CAN) for language. Z-scores computed based on age-, sex-, and education-matched normative tables were employed to determine whether performance on each task was impaired (z < -1.5 USD). This information was pooled across tasks to classify participants as showing generalized (at least two domains affected), domain-specific (only one domain affected), or no cognitive impairment. We then constructed whole brain structural connectomes based on Diffusion Tensor Imaging (DTI) using the Automated Anatomical Labelling (AAL) atlas. From the structural connectome, we calculated global efficiency, a measure of the distance between nodes in a network that reflects integrated processing. We hypothesized that higher structural network efficiency would be associated with less or no impairment.
Results: A total of 34% of the sample was classified as no impairment, 46% as domain- specific impairment, and 20% as generalized impairment. While controlling for age, education, and disease duration, an analysis of covariance (ANCOVA) revealed that global efficiency was different across the three phenotypes F(2, 54)=6.15, p=.004. Age was also significant in the model, (F(1,54)= 6.99, p=.011) while education and duration were not. The analysis revealed that lower global efficiency was lower for the generalized impairment group.
Conclusions: Our findings demonstrate that patients with TLE who demonstrate generalized cognitive impairment have decreased network global efficiency compared to non-impaired patients. This finding reveals that structural aberrant plasticity in patients with TLE has consequences for disease symptoms that extend beyond seizure, such as cognitive impairment.
Funding: NIH/NINDS (R01 NS088748)
Neuro Imaging