Any MS phenotype according to the revised McDonald’s criteria123 124

Aged 18 years or older

Any ethnicity

Disability status score on the Expanded Disability Status Scale (EDSS)41 of 2.0–5.0

Stable disease; no clinical evidence of disease activity

Ability to speak and understand German language

Significant concomitant diseases (such as malignant diseases, other neurological or psychiatric disorders, musculoskeletal problems affecting walking, pain, uncorrected visual or hearing impairment)

Cognitive impairment as defined by a MoCA cut-off score of 26/30 (<26=impaired cognition)87

Anxiety or depression as signified by a HADS anxiety82 or depression subscale score of 11/2183 or suicidality as evaluated by a narrative screening79

Pregnancy

Relapse of MS within the last 3 months before the study

Any medication initiation or change (including corticosteroids) or any physiotherapy change or inpatient rehabilitation within 3 months prior to the study

Any change of symptomatic treatment affecting walking (medication or physiotherapy) or of disease modifying treatment during the study will lead to an exclusion of the participant from further analysis

Age-matched and gender-matched

Without any history of neurological, psychiatric or orthopaedic disorders

Metallic or electricity conducting implants or prostheses (cardiac pacemaker, insulin pump, middle-ear implants, heart valve or hip prostheses, artificial teeth, hearing aid, etc) in or on the body

Non-removable metal parts (coil, braces, etc) or metal shrapnel in or on the body

Tattoos in the head or neck area, nicotine plasters or cosmetic eye modifications

Pregnancy

Epilepsy

Claustrophobia