Pattern of presentation of multiple sclerosis in Saudi Arabia: analysis based on clinical and paraclinical features.

We studied 89 MS patients comprising 38 males and 51 females seen over a 10-year period. The hospital frequency was 25/100,000 patients. The diagnosis was mainly clinical and was supported by neuroimaging, cerebrospinal fluid analysis and neurophysiological tests. Sixty-five patients (73%) were Saudis and the peak age of onset was in the third decade. Fifty-two patients (58.4%) had clinically definite MS, 17 (19.1%) had laboratory-supported definite MS, 15 (16.9%) were clinically probable MS cases and the remaining 5 (5.6%) had laboratory-supported probable MS. The mean age at onset of Saudi patients (25.9 years) was lower than that of the non-Saudis (29.4 years; p < 0.001). Involvement of the pyramidal system was the commonest mode of presentation. The clinical course was relapsing-remitting in 60.7%, progressive-relapsing in 20.2% and primary progressive in 19.1%. The number of systems involved was significantly associated with the duration of disease (p < 0.001). The demographic features and the variability of clinical presentation of Saudi MS patients is similar to the results from neighbouring countries. Combination of clinical features and paraclinical tests is essential for accurate determination of extent of dissemination and for unmasking clinically silent lesions.