Brain Structural Changes and Cognitive-Clinical Profiles in Late-Onset Unexplained Epilepsy.

Area of Science:

• Neurology
• Neuroimaging
• Cognitive Neuroscience

Background:

• Epilepsy incidence is bimodal, with a second peak after age 55.
• Late-onset unexplained epilepsy (LOUE) often lacks identifiable causes, with prior imaging suggesting mesiotemporal atrophy.
• Understanding structural brain alterations in LOUE is crucial for diagnosis and management.

Purpose of the Study:

• To quantify whole-brain cortical and deep gray matter alterations in LOUE.
• To investigate the association between these structural changes and cognitive/clinical measures in LOUE patients.

Main Methods:

• Prospective recruitment of LOUE patients and comparison with healthy older adults.
• Utilized 3T structural MRI to extract cortical thickness and deep gray matter volumes.
• Employed linear models for group comparisons and correlation analyses with cognitive and clinical data.

Main Results:

• LOUE patients exhibited reduced cortical thickness in sensory/mesiotemporal regions and decreased pallidum/putamen volumes.
• Structural reductions correlated with poorer performance on fluency and memory tasks.
• Increased thickness in the inferior frontal gyrus and thalamic volume were observed, particularly in patients with focal seizures.

Conclusions:

• LOUE is associated with more extensive brain structural changes than previously understood.
• These changes are linked to cognitive vulnerabilities, indicating potential overlap with neurodegenerative processes.
• Findings suggest LOUE may represent a spectrum between epilepsy and neurodegeneration.