Background: We conducted a study to determine the incidence of multiple sclerosis (MS) among the whole Icelandic population during a 6-year period (2002–2007).
Methods: We included all Icelandic residents diagnosed with MS during the study period. Cases were identified from records of the only neurology department in Iceland, plus the records of all practicing neurologists and all radiology departments. All patients had experienced at least two confirmed MS relapses (i.e. clinically definite MS) or had primary progressive MS as defined by the Poser criteria.
Results:We identified 136 individuals who met the inclusion criteria, including 102 (75%) women. The mean age at diagnosis was 36.3 years (women 35.7 years, men 38.3 years). Average annual incidence was 7.6 per 100,000 population. All but one patient (99%) had an MRI study done at diagnosis and 61% of these (83/135) fulfilled the Barkhof criteria for diagnosis of MS; one had a normal MRI. A visual evoked potential test was done in 68% (93/136) at the time of diagnosis and 44% (41/93) were abnormal. Spinal fluid was obtained from 78% (106/136), and 75% (80/106) had oligoclonal bands.
Conclusion:A total population study is the most reliable method of determining the spectrum of clinical symptoms and the results of investigations in MS patients at diagnosis.
RothmanKJGreenlandSLashTL. Modern epidemiology20083rd ed. Lippincott Williams & Wilkins, PA, USA.
2.
HaderWJYeeIM. Incidence and prevalence of multiple sclerosis in Saskatoon, Saskatchewan. Neurology2007; 69: 1224–1229.
3.
BenedikzJStefanssonMGuomundssonJJonasdottirAFossdalRGulcherJ. The natural history of untreated multiple sclerosis in Iceland. A total population-based 50 year prospective study. Clin Neurol Neurosurg104: 208–210.
4.
GudmundssonKRBergmannSBjornssonOJEllertssonAB. Further studies on multiple sclerosis in Iceland. J Neurol Sci1974; 21: 47–58.
PoserCMPatyDWScheinbergLMcDonaldWIDavisFAEbersGC. New diagnostic criteria for multiple sclerosis: guidelines for research protocols. Ann Neurol1983; 13: 227–231.
7.
BarkhofFFilippiMMillerDHScheltensPCampiAPolmanCH. Comparison of MRI criteria at first presentation to predict conversion to clinically definite multiple sclerosis. Brain1997; 120: 2059–2069.
8.
CeliusEGVandvikB. Multiple sclerosis in Oslo, Norway: prevalence on 1 January 1995 and incidence over a 25-year period. Eur J Neurol2001; 8: 463–469.
9.
SumelahtiMLTienariPJHakamaMWikstromJ. Multiple sclerosis in Finland: incidence trends and differences in relapsing remitting and primary progressive disease courses. J Neurol Neurosurg Psychiatry2003; 74: 25–28.
10.
RothwellPMCharltonD. High incidence and prevalence of multiple sclerosis in south east Scotland: evidence of a genetic predisposition. J Neurol Neurosurg Psychiatry1998; 64: 730–735.
11.
MayrWTPittockSJMcClellandRLJorgensenNWNoseworthyJHRodriguezM. Incidence and prevalence of multiple sclerosis in Olmsted County, Minnesota, 1985–2000. Neurology2003; 61: 1373–1377.
12.
McDonaldWICompstonAEdanGGoodkinDHartungHPLublinFD. Recommended diagnostic criteria for multiple sclerosis: guidelines from the International Panel on the diagnosis of multiple sclerosis. Ann Neurol2001; 50: 121–127.
13.
HirstCIngramGPickersgillTSwinglerRCompstonDARobertsonNP. Increasing prevalence and incidence of multiple sclerosis in South East Wales. J Neurol Neurosurg Psychiatry2009; 80: 386–391.
14.
SarasojaTWikstromJPaltamaaJHakamaMSumelahtiML. Occurrence of multiple sclerosis in central Finland: a regional and temporal comparison during 30 years. Acta Neurol Scand2004; 110: 331–336.
