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Review of studies of incidence of MS over several decades in seven geographical areas scattered over Scandinavia and Finland have shown that incidence rates fluctuate significantly with time in most of the areas but in an inconsistent pattern. The incidence appeared to the lowest in the northernmost parts of Norway indicating that the well-known north-south gradient for risk of MS does not hold true for high latitudes.
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N. Koch–Henriksen (1995) studied this question.
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