Trial protocol: Feasibility of neuromodulation with connectivity-guided intermittent theta-burst stimulation for improving cognition in multiple sclerosis.

Cognitive impairment in multiple sclerosis (MS) can adversely impact participation in employment, activities of daily living, and wider society. It affects 40-70% of people living with MS (pwMS). There are few effective treatments for cognitive impairment in people with MS. Neuromodulation with intermittent theta-burst stimulation (iTBS) has potential for treating cognitive impairment in pwMS. This single-centre mixed-methods feasibility randomised controlled trial (NCT04931953) will assess feasibility, acceptability, and tolerability of procedures used for applying iTBS for improving cognitive performance in pwMS. Participants will be randomised into three intervention groups with varying lengths of iTBS treatment (from 1 to 4 weeks) and a sham-control group. Quantitative data will be collected at three time points (baseline, end of intervention, and 8-week follow-up). End of the intervention semi-structured interviews will explore the views and experiences of the participants receiving the intervention, analysed using framework analysis. Quantitative and qualitative data will be synthesised to explore the impact of the iTBS intervention. Ethical approval has been received from the Health Research Authority (21/LO/0506) and recruitment started in June 2022. The results will inform the design of an RCT of the efficacy of iTBS as a therapeutic intervention for cognitive impairment in pwMS.