(xxix) Method for determining MEP size during analysis.
(xxx) Size of unconditioned MEP.
(xxxi) Disease duration in MS.
(xxxii) Disease severity in MS.
(xxxiii) MS subtype (i.e., relapsing-remitting and progressive).
(xxxiv) Participants experiencing a relapse in MS.
(xxxv) Participants receiving corticosteroid treatment for MS.
(xxxvi) Participants undergoing immunomodulatory treatment for MS.
(xxxvii) Participants taking nonprescription or recreational drugs (e.g., caffeine and nicotine).
(xxxviii) Room or skin temperature reported.
CNS: central nervous system; EMG: electromyography; MEP: motor-evoked potential; MS: multiple sclerosis. Criterion (xxii) was disregarded because we did not examine longitudinal studies. ǂCriteria (xxvi), (xxvii), and (xxviii) were marked NA, when studies did not utilize paired-pulse TMS measures.