Lesion symptom map of cognitive-postural interference in multiple sclerosis.

Area of Science:

• Neuroscience
• Neurology
• Biomedical Engineering

Background:

• Cognitive-postural interference (CPI) is a common issue in multiple sclerosis (MS).
• Understanding the underlying brain structure-function relationship in MS is crucial for managing CPI.
• Previous research has not fully elucidated the specific lesion locations contributing to CPI in MS.

Purpose of the Study:

• To investigate the disease-altered structure-function relationship of the cognitive-postural interference (CPI) phenomenon in multiple sclerosis (MS).
• To identify specific brain lesion locations associated with impaired dual-task balance control in MS patients.

Main Methods:

• Postural sway was measured using a force platform in 96 MS patients and 48 healthy controls during single-task and dual-task (Stroop test) conditions.
• Dual-task cost (DTC) of balance was calculated.
• Brain magnetic resonance imaging (MRI) was used to obtain T1 and T2 lesion masks, lesion volumes, and normalized brain volume (NBV).
• Voxel-based lesion symptom mapping (VLSM) analyses were performed to correlate DTC with lesion locations.

Main Results:

• MS patients exhibited significantly greater DTC than controls.
• T1 lesion volume showed a significant negative correlation with DTC, but VLSM analysis with T1 lesions did not reveal specific associations.
• Clusters of T2 lesions in the anterior and superior corona radiata (bilaterally) were significantly correlated with DTC.
• Multivariable regression confirmed the association between T2 lesion locations and DTC, independent of NBV.

Conclusions:

• The CPI phenomenon in MS is associated with T2 lesions in specific white matter tracts.
• These affected areas, particularly the corona radiata, are implicated in task-switching and divided attention.
• Disconnection within these specific neural pathways likely underlies the observed cognitive-postural interference in MS.