A majority of patients with multiple sclerosis initially presents with a single demyelinating event, e.g. in the optic nerves, brain, brainstem or spinal cord, referred to as a clinically isolated syndrome (CIS). Not all patients with CIS get a relapse and develop multiple sclerosis but in those patients who do, irreversible damage of the central nervous system, e.g. axonal damage, is already detectable in that early stage of disease. Early initiation of immunomodulatory therapy is crucial for patients with clinically isolated syndrome who are at high risk for the development of multiple sclerosis. Vice versa identification of low risk patients could help to avoid an unnecessary therapy. In this prospective observational study we want to follow up patients with CIS and early multiple sclerosis over a period of four years and obtain clinical, laboratory and MRI - data in order to identify risk factors for relapses, prognostic factors and therapy response markers.

Inclusion Criteria:

• age > 18 years
• signed informed consent
• clinically isolated syndrome within the last 6 months
• diagnosis of multiple sclerosis within the last two years

Exclusion Criteria:

• eye disease that could interfere with OCT (e.g. glaucoma, diabetic retinopathy)
• secondary progressive multiple sclerosis
• pregnancy
• contraindications for MRI, e.g. pacemaker, metal implants, allergy against gadolinium
• alcohol or drug abuse

Patients will be recruted at neurological outpatient clinics and neurologcial clinics of the charité and neurologists' medical practices.