rTMS affects working memory performance, brain activation and functional connectivity in patients with multiple...

Area of Science:

• Neuroscience
• Neurology
• Rehabilitation Medicine

Background:

• Multiple Sclerosis (MS) is a demyelinating disease affecting the central nervous system.
• Cognitive impairment, particularly in working memory, is a common symptom in MS.
• Current rehabilitation strategies for MS-related cognitive dysfunction are limited.

Purpose of the Study:

• To investigate the effects of high-frequency repetitive transcranial magnetic stimulation (rTMS) on working memory in MS patients.
• To assess changes in task-related brain activation and functional connectivity following rTMS.
• To compare rTMS effects between MS patients and healthy controls.

Main Methods:

• 17 MS patients and 11 healthy controls (HCs) participated in three sessions: baseline, real-rTMS, and sham-rTMS.
• Repetitive TMS (10 Hz) was applied to the right dorsolateral prefrontal cortex (DLPFC) before N-back tasks within an MRI scanner.
• Functional MRI measured brain activation and functional connectivity changes related to the N-back task performance.

Main Results:

• N-back task accuracy improved in MS patients after real-rTMS compared to baseline and sham conditions.
• MS patients exhibited reduced frontal hyperactivation after real-rTMS, shifting towards HC patterns.
• Functional connectivity between the right DLPFC and regions including the caudate nucleus and cingulate gyrus increased post-rTMS in MS patients.

Conclusions:

• Real-rTMS enhanced working memory performance in MS patients.
• rTMS modulated brain activation and connectivity, potentially improving network efficiency in MS.
• These findings support the potential of rTMS as a therapeutic tool for cognitive rehabilitation in multiple sclerosis.