Information processing speed, neural efficiency, and working memory performance in multiple sclerosis: differential...

Area of Science:

• Neuroscience
• Neurology

Background:

• Multiple sclerosis (MS) is a CNS neurodegenerative disorder affecting white and gray matter.
• MS is associated with cognitive impairments, including processing speed (PS), executive function, and working memory (WM).

Purpose of the Study:

• To investigate the specifics of cognitive deficits in MS patients.
• To examine the relationship between cognitive performance and structural brain damage using MRI.

Main Methods:

• A visual n-back task with three WM load conditions was employed.
• WM performance (accuracy), PS (reaction time), and processing efficiency (RTSD) were measured.
• Behavioral data were correlated with quantitative MRI measures of white and gray matter integrity.

Main Results:

• MS patients exhibited slower PS and reduced processing efficiency compared to controls, even at low WM loads.
• Accuracy on match trials differentiated MS patients from controls.
• Lower accuracy at high WM loads correlated with global gray and white matter atrophy.
• Slowed PS and processing inefficiency were primarily linked to white matter atrophy.

Conclusions:

• Cognitive deficits in MS are related to structural brain damage.
• The strongest relationships between cognitive function and MRI measures were observed during high WM load conditions requiring executive control.
• These findings suggest impaired connectivity in frontal cortical systems contributes to cognitive dysfunction in MS.