Background: To establish the early risk of multiple sclerosis (MS) following isolated demyelinating syndromes.
Patients and method: 36 patients with optic neuritis, 24 with brainstem syndromes, 27 with spinal cord syndromes and 8 patients with a poliregional syndrome were included in a prospective protocol: including clinical data, immunological determinations, oligoclonal bands, visual, somestesic and brainstem evoked potentials and a magnetic resonance imaging (MRI) study.
Results: MRI showed the presence of signal abnormalities in 70% of the patients. The conversion rate (CR) was 18.5%. In patients with a normal MRI, CR was 4% compared to 26% in patients with an abnormal MRI (p = 0.05).
Conclusions: The early conversion rate to MS is significantly increased when MRI is abnormal.