Intermittent Theta-Burst Stimulation for Lower-Limb Spasticity and Pain in Multiple Sclerosis

Multiple sclerosis (MS) is a chronic inflammatory and neurodegenerative disease of thecentral nervous system. Lower‐limb spasticity and neuropathic pain can substantiallyimpair mobility, daily functioning, and quality of life. Current symptomatic treatmentsinclude oral antispastic medication and targeted botulinum toxin type A injections, buttheir effects may be incomplete or time‐limited. Intermittent theta‐burst stimulation isa repetitive transcranial magnetic stimulation protocol with the potential to modulatecortical and corticospinal excitability.The study will determine whether active iTBS applied over the primary motor cortexproduces a greater reduction in lower‐limb spasticity and neuropathic pain than sham iTBSin patients with MS.This is a randomized, two‐arm, parallel‐group, sham‐controlled, assessor‐blinded clinicalstudy conducted at the Multiple Sclerosis Centre of the 2nd Department of Neurology,Faculty of Medicine, Comenius University Bratislava and University Hospital Bratislava.Eligible participants will be randomized to active iTBS or sham iTBS. Stimulation willtarget the primary motor cortex contralateral to the more affected lower limb and thecortical representation of the muscle group corresponding to the dominant spasticpattern, identified using motor‐evoked potentials and neuronavigation. Participants willundergo five sessions on consecutive weekdays. The active protocol comprises 1,200 pulsesper day, delivered as two 600‐pulse blocks separated by a 15‐minute inter‐block interval.Clinical and neurophysiological assessments will be performed at baseline and at Weeks 2and 4 after the intervention by an assessor blinded to treatment allocation. Assessmentsinclude the Tardieu Scale, pain measures, MS‐specific quality‐of‐life and symptomquestionnaires, and the H/M ratio measured by electromyography. Participants with apersistent clinical indication after completion of the four‐week follow‐up may receivebotulinum toxin type A as standard‐of‐care rescue treatment.