Abnormal brain functional network dynamics in narcolepsy type 1 patients

Area of Science:

• Neuroscience
• Sleep Medicine
• Computational Psychiatry

Background:

• Narcolepsy type 1 (NT1) is a chronic neurological disorder affecting sleep-wake regulation.
• Understanding the underlying brain network alterations in NT1 is crucial for developing targeted therapies.

Purpose of the Study:

• To investigate dynamic functional connectivity (dFC) in drug-naïve NT1 patients.
• To explore the association between clinical features and aberrant brain connectivity in NT1.

Main Methods:

• Employed a sliding-window approach, clustering state analysis, and graph-theory methods to analyze dFC in 80 NT1 patients, 30 idiopathic hypersomnia (IH) patients, and 60 healthy controls.
• Evaluated relationships between clinical features and identified dFC abnormalities.

Main Results:

• Identified three distinct dFC brain states: State I (frequent, sparse), State II (less frequent, strong), and State III (less frequent, sparse).
• NT1 patients showed increased occurrence and dwell time in State II, while IH patients and controls predominantly exhibited State III.
• State III metrics negatively correlated with sleep latency in NT1 patients. Both IH and NT1 groups displayed abnormal global brain network integration.

Conclusions:

• Abnormal temporal patterns and functional segregation in NT1 patients underscore network vulnerability.
• The findings link altered brain network dynamics to the severity of sleepiness and topological property deficits in NT1.