Step initiation interferes with working memory in nondisabled patients with the earliest multiple sclerosis-A...

Area of Science:

• Neuroscience
• Neurology
• Rehabilitation Science

Background:

• Multiple sclerosis (MS) significantly impacts balance and cognitive functions.
• Cognitive-motor interference (CMI) contributes to balance deficits in MS, but its role in early disease stages is understudied.
• Step initiation (SI) and anticipatory postural adjustments (APAs) are crucial for balance and linked to falls in MS.

Purpose of the Study:

• To investigate CMI between SI and working memory systems in patients with clinically isolated syndrome (CIS) suggestive of MS.
• To compare CMI in CIS patients with age- and sex-matched healthy controls.

Main Methods:

• Twenty CIS patients (optic neuritis) and 20 controls performed SI under single-task and dual-task conditions (spatial and verbal working memory).
• Center of pressure measures assessed APAs.
• CMI was calculated by combining performance decrements in cognitive and motor tasks.

Main Results:

• Cognitive task performance was more impaired by dual-tasking in CIS patients than controls.
• APA parameters remained unaffected by dual-tasking in both groups.
• CMI was significantly higher in CIS patients compared to healthy controls.

Conclusions:

• The findings suggest that CMI is affected even in the earliest stages of MS.
• The central executive appears to be the primary component of CMI between SI and working memory.
• Increased CMI in early MS may stem from reduced divided attention capacity, with patients prioritizing motor control for balance.