Disrupted periodic spatiotemporal pattern and dynamic reorganization of its basic states in generalized epilepsy

Area of Science:

• Neuroscience
• Epilepsy Research
• Brain Network Dynamics

Background:

• The anti-correlation between the default mode network (DMN) and task-positive network (TPN) is a hallmark of healthy brain function.
• Disruptions in this DMN-TPN anti-correlation are observed in idiopathic generalized epilepsy (IGE) and linked to seizures.

Purpose of the Study:

• To investigate the relationship between DMN-TPN anti-correlation and epileptic activity in IGE using periodic spatiotemporal patterns (PSTP).
• To provide novel insights into the neural mechanisms underlying IGE.

Main Methods:

• Resting-state fMRI data from healthy controls (HC) and IGE patients were analyzed.
• A novel PSTP-finding algorithm was employed to detect dynamic periodic patterns in DMN-TPN anti-correlation fluctuations.
• The Hilbert transform and analysis of intrinsic neural timescales (INT) were utilized.

Main Results:

• IGE patients showed reduced DMN-TPN anti-correlation, especially during TPN-dominant states.
• Greater dynamic instability and more frequent state transitions were observed in IGE patients.
• Lower correlations between period length and INT were found in cognitive regions of IGE patients.

Conclusions:

• Dynamic switching between DMN and TPN is impaired in IGE, characterized by weaker and less balanced interactions.
• Disruptions in periodic brain rhythms are associated with cognitive deficits in IGE.
• The PSTP framework offers a spatiotemporal perspective on abnormal brain rhythms in IGE.