Early structural hub disruption leads to premature functional adaption in multiple sclerosis

Area of Science:

• Neuroscience
• Medical Imaging
• Network Science

Background:

• Multiple Sclerosis (MS) involves inflammation and neurodegeneration, impacting brain networks.
• The role of functional connectivity changes in MS (adaptation vs. response) remains unclear.
• Understanding network dynamics is crucial for characterizing MS pathophysiology.

Purpose of the Study:

• To investigate the long-term topological changes in structural and functional brain networks in MS patients.
• To compare network dynamics in MS patients with healthy controls across different age groups.
• To determine if MS patients exhibit a functional adaptation response similar to healthy aging.

Main Methods:

• Analysis of brain connectomes from 65 MS patients and 59 controls over seven years.
• Utilized diffusion-weighted imaging and resting-state MRI data.
• Applied graph theory and the hub disruption index to assess network topology and connectivity perturbation.

Main Results:

• Healthy individuals show a transient increase in functional hub connectivity with aging, compensating for structural loss.
• MS patients exhibit early structural hub disruption and lack the typical age-related functional connectivity upregulation.
• MS patients show early functional reorganisation but transition directly to an 'exhausted' hub connectivity state.

Conclusions:

• MS patients may mount an early physiological response to structural damage, but it leads to accelerated hub overload.
• The absence of age-related functional compensation in MS could contribute to faster neurodegeneration.
• Lack of this compensatory mechanism might be a factor in the onset of chronic progression in middle age.