This invention provides a method of treating a subject afflicted with multiple sclerosis or presenting a clinically isolated syndrome comprising administering to the subject fampridine as an add-on therapy to or in combination with laquinimod. This invention also provides a package comprising laquinimod and fampridine for treating a subject afflicted with multiple sclerosis or presenting a clinically isolated syndrome. This invention also provides fampridine for use as an add-on therapy or in combination with laquinimod in treating a subject afflicted with multiple sclerosis or presenting a clinically isolated syndrome. This invention also provides a pharmaceutical composition comprising laquinimod and fampridine for use in treating a subject afflicted with multiple sclerosis or presenting a clinically isolated syndrome. This invention further provides use of laquinimod and fampridine in the preparation of a combination for treating a subject afflicted with multiple sclerosis or presenting a clinically isolated syndrome.