Table 1.

Estimated prevalence of seizures in multiple sclerosis – population-based cohort studies

Location	Number of subjects	Number with seizure	Prevalence (Incidence)	MS duration prior to seizure mean ± SD	Reference
Uusimaa, Finland	599	21	3.5%†	6.45 ± 7.4 years	[21]
Hordaland, Norway	423	17	4.0%	7.4 ± 6.3 years	[19]
Iceland	188		2.3% (SIR=3.0)	5.0 ± 4.1 years	[24]
Rochester, MN	208	5	2.4% (SIR=1.3) ††	9.6 ± 4.5 years	[23]
Gothenburg, Sweden	255	20	3.5% (SIR=7.8)	*	[20]
Catania, Italy	170	4	2.4% (SIR=3.3)	6.25 ± 6.45 years	[22]

SIR = Standardized incidence ratio

^*Data not available

^†SIR not calculated, reported prevalence was estimated to be 4-fold greater than the general population.

^††Age-adjusted incidence of seizure during the lifetime of patients with MS estimated to be 82/100,000; age-adjusted incidence in the general population of Rochester, Minnesota, 61/100,000.