Lack of correlation between cortical demyelination and white matter pathologic changes in multiple sclerosis

Area of Science:

• Neuropathology
• Neuroimaging
• Multiple Sclerosis Research

Background:

• Chronic multiple sclerosis (MS) is characterized by extensive subpial cortical demyelination.
• Understanding the relationship between gray matter and white matter (WM) pathology in MS is crucial.

Purpose of the Study:

• To investigate the association between subpial cortical demyelination in MS and focal or diffuse WM pathological features observed on magnetic resonance imaging (MR imaging).

Main Methods:

• Postmortem MR imaging findings were compared with histopathologic findings from brain donations.
• Two blinded observers assessed WM pathological changes using MR imaging and histopathology in MS patients with varying degrees of cortical demyelination.

Main Results:

• Extensive subpial demyelination was not significantly associated with increased focal or diffuse WM pathological changes on MR imaging or histopathology.
• No correlation was found between the extent of subpial demyelination and juxtacortical abnormalities on MR imaging.

Conclusions:

• Gray matter demyelination in MS appears to occur largely independently of white matter pathological changes.
• White matter abnormalities on MR imaging cannot reliably predict the presence or extent of cortical demyelination in clinical settings.