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Updated: May 7, 2026
Network Analysis of the Default Mode Network Using Functional Connectivity MRI in Temporal Lobe Epilepsy
Published on: August 5, 2014
Microstructural integrity of early- versus late-myelinating white matter tracts in medial temporal lobe epilepsy
Chu-Yu Lee1, Ali Tabesh, Andreana Benitez
1Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, South Carolina, U.S.A; Center for Biomedical Imaging, Medical University of South Carolina, Charleston, South Carolina, U.S.A.
Purpose:
Patients with medial temporal lobe epilepsy (MTLE) exhibit structural brain damage involving gray matter (GM) and white matter (WM). The mechanisms underlying tissue loss in MTLE are unclear and may be associated with a combination of seizure excitotoxicity and WM vulnerability. The goal of this study was to investigate whether late-myelinating WM tracts are more vulnerable to injury in MTLE compared with early myelinating tracts.
Methods:
Diffusional kurtosis imaging scans were obtained from 25 patients with MTLE and from 36 matched healthy controls. Diffusion measures from regions of interest (ROIs) for both late- and early myelinating WM tracts were analyzed. Regional Z-scores were computed with respect to normal controls to compare WM in early myelinating tracts versus late-myelinating tracts.
Key Findings:
We observed that late-myelinating tracts exhibited a larger decrease in mean, axial, and radial kurtosis compared with early myelinating tracts. We also observed that the change in radial kurtosis was more pronounced in late-myelinating tracts ipsilateral to the side of seizure onset.
Significance:
These results suggest a developmentally based preferential susceptibility of late-myelinating WM tracts to damage in MTLE. Brain injury in epilepsy may be due to the pathologic effects of seizures in combination with regional WM vulnerability.
Insights
Late-myelinating white matter (WM) tracts are more susceptible to damage in medial temporal lobe epilepsy (MTLE). This developmental vulnerability, combined with seizure effects, contributes to brain injury in epilepsy patients.
Area of Science:
- Neuroimaging
- Epilepsy Research
- White Matter Integrity
Background:
- Medial temporal lobe epilepsy (MTLE) is characterized by gray and white matter (WM) damage.
- The precise mechanisms of tissue loss in MTLE, potentially involving excitotoxicity and WM vulnerability, remain unclear.
Purpose of the Study:
- To investigate the differential vulnerability of late-myelinating versus early-myelinating WM tracts in MTLE.
- To determine if developmental myelination patterns influence WM injury in epilepsy.
Main Methods:
- Diffusional kurtosis imaging (DKI) was employed in 25 MTLE patients and 36 healthy controls.
- Diffusion measures were analyzed in regions of interest (ROIs) for both early and late-myelinating WM tracts.
- Regional Z-scores compared WM integrity between tract types relative to controls.
Main Results:
- Late-myelinating WM tracts showed significantly greater reductions in mean, axial, and radial kurtosis compared to early-myelinating tracts.
- The decrease in radial kurtosis was more pronounced in late-myelinating tracts on the same side as seizure onset.
- These findings indicate a preferential susceptibility of late-myelinating WM tracts.
Conclusions:
- Results suggest a developmental susceptibility of late-myelinating WM tracts to damage in MTLE.
- Epilepsy-related brain injury may result from a combination of seizure pathology and regional WM vulnerability.
- Understanding these mechanisms can inform therapeutic strategies for epilepsy.
