Evaluation of the Positron Emission Tomography (PET) Tracer ZK 6032924 in Patients With Multiple Sclerosis Compared to Healthy Volunteers

Inclusion Criteria: Healthy volunteers for brain imaging: * males or females, age 20 - 55 years * assessment of the brain MRI as "normal (age-appropriate)" * absence of any sign of CNS disease, no co-medi cation Patients for brain imaging * males or females, age 20 - 55 years * patients with previously diagnosed MS, presenting with acute relapse, without any current immunomodulating therapy for MS ("drug-naïve"), or patients presenting with first clinical episode suggestive of demyelinating disease (Clinically Isolated Syndrome, CIS) * patients with previously diagnosed MS, presenting with acute relapse, receiving currently immunomodulatory therapy exclusively with interferon β * MRI: \>/= 2 T2 lesions and \>/= 1 Gadolinium- (Gd-) enhancing lesion Exclusion Criteria: Exclusion criteria for all healthy volunteers and patients: * Pregnancy or lactation * Any disease, condition, or concomitant medications that significantly compromises the function of the body systems and could result in excessive accumulation, impaired metabolism, altered excretion of the radiotracer, or might interfere with the conduct of the study or interpretation of the results * other forms of diseases with neuroinflammatory components