Altered functional connectivity in default mode network in absence epilepsy: a resting-state fMRI study

Area of Science:

• Neuroscience
• Clinical Neurology
• Brain Imaging

Background:

• Dysfunctional default mode network (DMN) is implicated in various mental disorders.
• Epilepsy, particularly absence epilepsy, may involve DMN alterations.
• Interictal epileptic discharges could confound DMN functional connectivity studies.

Purpose of the Study:

• To investigate DMN functional connectivity in absence epilepsy patients during seizure-free periods.
• To determine if absence epilepsy is associated with altered DMN integration.
• To explore the relationship between DMN connectivity and epilepsy duration.

Main Methods:

• Resting-state functional magnetic resonance imaging (fMRI) was employed.
• 12 absence epilepsy patients and 14 healthy controls were studied.
• Cross-correlation analysis was used to assess DMN functional connectivity, with a focus on the posterior cingulate cortex and region-wise calculations.

Main Results:

• Absence epilepsy patients exhibited decreased DMN integration compared to controls.
• Region-wise functional connectivity within the frontal, parietal, and temporal lobes was significantly reduced in patients.
• Frontoparietal functional connectivity showed a negative correlation with epilepsy duration.

Conclusions:

• Absence epilepsy is associated with DMN abnormalities, even in the absence of interictal epileptic discharges.
• Reduced DMN functional connectivity may reflect underlying anatomo-functional integration deficits.
• These DMN alterations could contribute to cognitive impairments observed in absence epilepsy.