Time course of lesion-induced atrophy in multiple sclerosis

Area of Science:

• Neuroimaging
• Neurology
• Multiple Sclerosis Research

Background:

• White matter (WM) tract disruption is linked to deep gray matter (DGM) volume loss in people with multiple sclerosis (PwMS).
• The precise timing of this relationship is not well understood.

Purpose of the Study:

• To investigate the temporal relationship between white matter (WM) tract disruption and deep gray matter (DGM) atrophy in people with multiple sclerosis (PwMS).
• To determine the time lag between new WM lesions and subsequent DGM volume loss.

Main Methods:

• Retrospective analysis of annual serial MRI scans from 181 PwMS over 10 years.
• Measurement of annualized thalamic and DGM atrophy and connected WM tract disruption.
• Time series analysis using sliding windows and regression models to assess the predictive influence of WM disruption on DGM atrophy.

Main Results:

• WM tract disruptions connected to the thalamus were significantly associated with thalamic atrophy one year later.
• WM tract disruptions connected to the DGM were significantly associated with DGM atrophy one year later.
• No significant association was found for concurrent WM disruption or disruption preceding atrophy by 2-4 years.

Conclusions:

• Thalamic and DGM atrophy rates in PwMS are elevated specifically within one year following new WM tract disruption.
• Clinicians and researchers should anticipate gray matter atrophy approximately one year after new lesion development in connected white matter.