A clinical longitudinal study of multiple sclerosis in Cantabria, Spain

There are many studies that analyze the clinical course of multiple sclerosis (MS), but only a few of them observed patients from their first episode. We report a MS series of patients longitudinally evaluated from the onset of the disease and compare outcome between immunosuppressive treatment and non-treatment groups.

Patients were included when their follow-up was at least three years and serial examination was available. Poser's criteria were used for diagnosis. We measured neurological impairment according to Kurtzke's expanded disability status scale (EDSS).

Fifty-five MS patients were followed-up. Forty-six had clinically defined and nine clinically probable MS. Thirty-three patients had relapsing-remitting, 11 had secondary-progressive and 11 had primary-progressive MS. Mean age of onset of the disease was 31.1 years and mean duration of follow-up was seven years. Pyramidal weakness and sensory symptoms were the most common initial manifestations. Median time to reach EDSS-3 and EDSS-6 from onset was 4.5 and 7.5 years, respectively. From a total of 23 patients with follow-up of 10 or more years, 11 (48 %) had benign MS. The average time from onset of MS to secondary-progressive was 6.1 years. There were no significant differences between treatment and non-treatment patients.

Longitudinal studies starting from early clinical course of MS are most useful in determining its semeiology, clinical pattern and outcome. Our results call for caution in initiating early immunosuppressive or immunomodulatory therapy.