Altered Small-World Functional Network Topology in Patients with Optic Neuritis: A Resting-State fMRI Study

Area of Science:

• Neuroscience
• Medical Imaging
• Graph Theory

Background:

• Optic neuritis (ON) is an inflammatory condition affecting the optic nerve.
• Understanding brain network alterations in ON is crucial for diagnosing and treating associated cognitive deficits.

Purpose of the Study:

• To investigate changes in small-world topology and functional brain connectivity in patients with ON using resting-state functional magnetic resonance imaging (rs-fMRI).
• To analyze brain network characteristics and identify differences between ON patients and healthy controls (HC).

Main Methods:

• rs-fMRI data acquired from 21 ON patients and 21 matched HC.
• Brain parcellation into 116 regions of interest, followed by calculation of small-world network parameters and area under the curve (AUC).
• Statistical analysis using independent sample t-tests and network-based statistics to compare groups.

Main Results:

• Both groups displayed small-world network attributes.
• ON patients showed higher global network efficiency, normalized clustering coefficient, and small-world value, but a lower clustering coefficient value compared to HC.
• Reduced functional connectivity strength was observed in ON patients across several brain regions, including the rolandic operculum, insula, amygdala, and cerebellum.

Conclusions:

• ON patients exhibit a distinct "small world" brain network topology compared to HC.
• The brain network in ON is characterized by reduced and abnormal connectivity, potentially leading to cognitive impairment.