Cognitive function in primary and secondary progressive multiple sclerosis: A multiparametric magnetic resonance...

Area of Science:

• Neuroscience
• Radiology
• Neurology

Background:

• Cognitive function differences between primary progressive multiple sclerosis (PPMS) and secondary progressive multiple sclerosis (SPMS) are not well understood.
• Multiple Sclerosis (MS) encompasses various forms, each with potentially distinct impacts on cognition.

Purpose of the Study:

• To compare cognitive performance between PPMS and SPMS patients.
• To identify structural and functional magnetic resonance imaging (MRI) correlates of cognitive function in PPMS and SPMS.

Main Methods:

• 183 MS patients (60 PPMS, 123 SPMS) and 75 controls underwent 3.0-T MRI.
• Cognitive function was assessed using the Brief Repeatable Battery of Neuropsychological Tests.
• Hierarchical linear regression analyzed MRI metrics (lesion volume, brain volume, white matter integrity, resting-state functional connectivity) in relation to global cognition.

Main Results:

• PPMS and SPMS groups demonstrated comparable cognitive domain z-scores.
• In PPMS, cognitive impairment correlated with medial lemniscus fractional anisotropy (FA) and gray matter volume.
• In SPMS, cognitive impairment correlated with fornix FA and white matter (WM) volume.

Conclusions:

• Neuropsychological performance was similar between PPMS and SPMS.
• Cognitive dysfunction in these MS subtypes is associated with unique structural MRI abnormalities and white matter tract involvement.
• Resting-state functional connectivity alterations did not significantly explain global cognitive functioning in either PPMS or SPMS.