Clinical aspects of multiple sclerosis in north-east Scotland with particular reference to its course and prognosis

The prognosis and course of multiple sclerosis (MS) and the factors that affect them were assessed in a group of 1055 patients, representing an unselected (epidemiological) sample observed in the north-east (Grampian region) of Scotland for a period ranging between 1 and 60 yrs. In 7% the disease began before the age of 20 yrs, in 12% after the age of 50 yrs, and in the remainder onset was between the ages of 20 and 50 yrs. The male/female ratio was 1:1.8. Mean disease duration in those observed until death (216 patients) was 24.5 yrs, with no significant difference between the sexes. Prognosis was assessed either by the interval between onset and death or by the degree of disability over a defined period of time. Depending on the length of follow-up, just over one-quarter (26%) to over one-third (36.3%) had a benign course and between 8.0 and 17.7% had a poor prognosis. Nearly a third had a remittent (32.8%) or relapsing cumulative (34%) course and 9% had a progressive course from the start. Several factors were noted to affect the prognosis. Prognosis was significantly better, independent of sex, in those with (1) an early onset (less than 40 yrs of age); (2) retrobulbar neuritis or a brainstem lesion or sensory symptoms alone at onset; (3) short duration of initial symptoms (less than 6 months); (4) a long onset--first relapse interval (greater than 1 yr); (5) a remittent course in the beginning and (6) lack of a family history of MS. The factors which predicted a poor prognosis included: (1) a late onset (greater than 40 yrs of age); (2) progressive course from the start; (3) multiple sites of lesions initially, or a cerebellar or spinal cord lesion at the onset; (4) psychiatric or persistent urinary symptoms at the onset or within 10 yrs; (5) persistent initial symptoms (beyond 1 yr); (6) early first relapse (within 6 months); (7) a family history of MS; (8) social class status IV and V; and (9) bilaterally prolonged visual evoked potential (VEP) P100 latency. Address in childhood and at the onset of the disease, changes in the CSF and CT brain scan were not of predictive value.