Disrupted Coupling Between the Spontaneous Fluctuation and Functional Connectivity in Idiopathic Generalized Epilepsy

Area of Science:

• Neuroscience
• Epileptology
• Medical Imaging

Background:

• Idiopathic generalized epilepsy (IGE) encompasses several epilepsy syndromes, including juvenile myoclonic epilepsy (JME) and generalized tonic-clonic seizures (GTCS).
• Resting-state functional magnetic resonance imaging (fMRI) is a key tool for investigating brain activity alterations in epilepsy.

Purpose of the Study:

• To comprehensively evaluate resting-state spontaneous brain activity and its alterations in patients with IGE and its subgroups (JME, GTCS).
• To analyze the coupling between amplitude of low frequency fluctuation (ALFF) and functional connectivity density (FCD) in IGE patients.

Main Methods:

• Resting-state fMRI data from 60 IGE patients and 60 healthy controls (HCs) were analyzed.
• Amplitude of low frequency fluctuation (ALFF), global FCD (gFCD), local FCD (lFCD), and long-range FCD (lrFCD) were computed.
• Voxel-wise and subject-wise analyses examined differences in ALFF, FCDs, and their coupling between groups.

Main Results:

• IGE patients exhibited reduced ALFF, gFCD, and lrFCD in the posterior default mode network (DMN).
• Decreased ALFF and increased ALFF-FCD coupling were observed in the cerebellum of IGE patients.
• JME patients showed increased coupling in the cerebellum and bilateral middle occipital gyrus compared to GTCS patients.

Conclusions:

• This study reveals multifactorial abnormalities within the DMN in IGE.
• Cerebellar abnormalities in IGE are associated with motor symptom dysfunction and may play a role in regulating generalized spike-wave discharges (GSWDs).