Objectives: To identify predictors of conversion to definite multiple sclerosis (MS) in patients with a cord clinically isolated syndrome.
Methods: The predictive values for conversion to MS of clinical, magnetic resonance imaging (MRI) and cerebrospinal fluid (CSF) variables in 114 patients with acute partial myelitis confirmed by a spinal cord lesion on MRI were studied. Other causes of cord syndromes were excluded.
Results: MS was diagnosed in 78 patients (86%) during 4.0 ± 1.9 years of follow-up. Some 67 of these patients had a second clinical episode. The diagnosis of isolated myelitis was maintained for 36 patients, 78% of whom (28 cases) were followed for at least 2 years, comparable to the MS patients. Age, bladder involvement, ≥ 2 cord lesions on MRI, ≥ 9 brain lesions, ≥ 3 periventricular lesions and intrathecal IgG synthesis predicted conversion to clinically definite MS. Multivariate logistic analysis identified three predictors of MS diagnosis: age ≤ 40 years, inflammatory CSF and ≥ 3 periventricular lesions on brain MRI.
Conclusion: Two out of three baseline factors (age, periventricular lesions and inflammatory CSF) predicted conversion to MS with better accuracy than the revised McDonald criteria for dissemination in space.