Minocycline in Clinically Isolated Syndromes (CIS)

Inclusion Criteria: * Age between 18 and 60 years. * First focal clinical episode suggestive of demyelinating disease within the previous 180 days (measured from onset of the first symptom to treatment start), based on the appearance of a neurological abnormality, present for at least 24 hours. * Objective clinical evidence must be present or documented. Patients will be included irrespective of whether the first clinical demyelinating episode was monosymptomatic (i.e. clinical evidence of a single lesion) or polysymptomatic (i.e. clinical evidence of more than one lesion). * At least two lesions on the T2-weighted brain MRI\* scan at least one of which is ovoid or periventricular or infratentorial. MRI eligibility will be determined centrally by the UBC MS/MRI Research Group.\*One lesion on spinal MRI may substitute for one brain lesion as per the 2005 McDonald Criteria. * Sexually active women of child-bearing potential must agree to use adequate contraception. * Written informed consent Exclusion Criteria: * Any disease other than MS that could better explain the patient's signs and symptoms. * Any previous clinical event reasonably attributable to acute demyelination, regardless of whether medical attention was obtained. * Complete transverse myelitis or bilateral optic neuritis. A waiver can be obtained for bilateral optic neuritis but must be obtained prior to randomization. Waivers must be approved by 3 neurologists including a member of the Clinical Eligibility / Endpoint Committee, a member of the DSMC, and by an experienced MS neurophthalmologist.