Participants

Twenty patients with a primary diagnosis of RRMS were recruited for this study at Dongzhimen Hospital, Beijing, China. All patients met the revised McDonald criteria (22) and classification standards for MS. Fifteen age and sex-matched right-handed healthy subjects were used as a control group. Healthy subjects had no history of neurological or psychiatric disease.

The inclusion criteria for RRMS patients were: (1) patients were in the remission stage of RRMS with no acute attack or exacerbation of MS during the last month; (2) patients were not taking any glucocorticoid medications; (3) patients’ medication and treatment had no significant recent adjustments; (4) patients had no history of serious psychiatric illness or neurological disease other than MS; (5) Chinese was their primary language; (6) patients were right-handed according to the modified Edinburgh Handedness Questionnaire (23); and (7) patients did not have any contraindications to MRI. Patients who had contraindications to MRI, poor quality MRI images, or showed one or more gadolinium-enhancing lesions during their baseline MRI were excluded.

A neurologist assessed patients’ disability using the EDSS (24) on the day of the neuropsychological assessment.