Glymphatic dysfunction impairs cognitive function via disrupted white matter network efficiency in primary insomnia:...

Area of Science:

• Neuroscience
• Sleep Medicine
• Cognitive Science

Background:

• Primary insomnia (PI) is increasingly viewed as a brain network disorder linked to cognitive impairment.
• Glymphatic system dysfunction, affecting brain clearance during sleep, is a potential cause of these deficits.
• The relationship between glymphatic activity, brain network efficiency, and cognitive function in PI is not well understood.

Purpose of the Study:

• To investigate the association between glymphatic function, structural brain network efficiency, and cognitive performance in primary insomnia.
• To explore the mediating roles of glymphatic function and network efficiency in the relationship between sleep quality and cognitive deficits in PI.

Main Methods:

• Diffusion tensor imaging (DTI) was used to assess glymphatic function (DTI-ALPS index) and structural white matter networks in 36 PI patients and 36 controls.
• Graph-theoretical metrics analyzed network efficiency, and the Psychomotor Vigilance Task (PVT) measured sustained attention.
• Correlational and mediation analyses examined the interplay between sleep quality (PSQI), glymphatic function, network properties, and cognitive performance.

Main Results:

• PI patients exhibited significantly lower DTI-ALPS index, prolonged PVT reaction times, and higher PSQI scores compared to healthy controls.
• The ALPS index positively correlated with global network efficiency and negatively with PSQI scores and PVT reaction times.
• Mediation analyses indicated that glymphatic function influenced network efficiency, which in turn affected attention performance.

Conclusions:

• Glymphatic dysfunction contributes to attention impairment in PI through disrupted structural network integration.
• These findings suggest that enhancing glymphatic health and white matter integrity could be therapeutic strategies for cognitive decline in insomnia.