Effect of progressive muscle relaxation on pain of multiple sclerosis patients

INTERVENTION: Intervention 1: Progressive muscle relaxation program: 90 sessions each session 45 minutes for three months. Intervention 2: Routine care. Progressive muscle relaxation program: 90 sessions each session 45 minutes for three months Rehabilitation Routine care CONDITION: Demyelinating diseases of the central nervous system Multiple sclerosis. ; Demyelinating diseases of the central nervous system PRIMARY OUTCOME: Pain. Timepoint: Baseline and 3 months after intervention. Method of measurement: visual analoge questionnaire. SECONDARY OUTCOME: Disease symptom. Timepoint: Baseline and 3 months after intervention. Method of measurement: Questionnaire. INCLUSION CRITERIA: INCLUSION CRITERIA: Presence of multiple sclerosis, ability to read and write Exclusion criteria: Presence of other diseases such as mental disorder, cognitive disorder, addiction, or other neurologic disorders