Pm. Rothwell et D. Charlton, HIGH-INCIDENCE AND PREVALENCE OF MULTIPLE-SCLEROSIS IN SOUTH EAST SCOTLAND - EVIDENCE OF A GENETIC PREDISPOSITION, Journal of Neurology, Neurosurgery and Psychiatry, 64(6), 1998, pp. 730-735
Objective-To determine the incidence and prevalence of multiple sclero
sis in the Lothian and Border Health Board Regions of south east Scotl
and. Methods-Incidence study: all patients were identified in whom a d
iagnosis of Poser category probable or definite multiple sclerosis was
made by a neurologist between 1992 and 1995. Prevalence study: all pa
tients known to have multiple sclerosis who were alive and resident in
the study area on 15 March 1995 were recorded. Results-The crude annu
al incidence rates of probable or definite multiple sclerosis per 100
000 population were the highest ever reported: 12.2 (95% confidence in
terval (95% CI) 10.8-13.7) in the Lothian Region and 10.1 (95% CI 6.6-
13.6) in the Border Region. A total of 1613 patients with multiple scl
erosis were resident in the study area, giving standardised prevalence
rates per 100 000 population of 203 (95% CI 192-214) in the Lothian R
egion and 219 (95% CI 191-251) in the Border Region. Prevalent cases w
ere more likely than expected to have a Scottish surname (risk ratio 1
.24, 95% CI 1.14-1.34). Conclusions-Orkney and Shetland were previousl
y thought to have by far the highest prevalence of multiple sclerosis
in the world: about double that found in England and Wales. However, t
he prevalence in south east Scotland is equally high, suggesting that
the Scottish population as a whole has a genetic susceptibility to the
disease, and undermining the hypothesis that patterns of infection sp
ecific to small sparsely populated island communities are important in
the causation of multiple sclerosis.