Motor cortex rTMS improves dexterity in relapsing-remitting and secondary progressive multiple sclerosis

Area of Science:

• Neuroscience
• Neurology
• Rehabilitation Medicine

Background:

• The motor cortex (MC) relies on excitatory input from the cerebellum, which is often impaired in individuals with cerebellar lesions.
• High-frequency repetitive transcranial magnetic stimulation (rTMS) can enhance cortical excitability, potentially compensating for reduced cerebellar drive to the MC.

Purpose of the Study:

• To investigate the efficacy of high-frequency motor cortex rTMS in improving cerebellar function and motor performance in patients with multiple sclerosis (MS) and dysmetria.
• To compare the effects of different rTMS protocols (two real sessions vs. one real and one sham session) on motor outcomes.

Main Methods:

• Twenty-four patients with relapsing-remitting MS (RRMS) and secondary progressive MS (SPMS) experiencing dysmetria were enrolled.
• Participants were randomized into two groups: Group A (two real MC rTMS sessions) and Group B (one real, one sham MC rTMS session).
• Motor function was assessed using the nine-hole pegboard task and the cerebellar functional system score (FSS) of the expanded disability status scale (EDSS).

Main Results:

• Group A demonstrated significant improvements in the nine-hole pegboard task completion time (P=0.002) and cerebellar FSS (P=0.000) immediately after treatment and at one-month follow-up.
• Relapsing-remitting MS patients showed greater improvement compared to secondary progressive MS patients.
• Group B did not exhibit any significant improvements in the assessed motor tasks or cerebellar function.

Conclusions:

• Motor cortex rTMS is a potentially effective therapeutic strategy for managing cerebellar impairment in both RRMS and SPMS patients.
• The observed benefits of MC rTMS on motor function and cerebellar FSS can be long-lasting, suggesting sustained therapeutic effects.