Arteriovenous Fistulae and Asymmetrical Asterixis

SIR-John L. Kiely and colleagues comment on the mixed patterns of prevalence rates for cerebral palsy in Western nations over recent decades'. In some reports there is a downward trend, in others a stable rate and in yet others fluctuations are reported, or even a rising rate. From Sweden, for example, Hagberg reported a decreased incidence of cerebral palsy. and especially of spastic and atactic diplegia among low-birthweight children between 1954 and 1970, followed by an increase i n the 1 9 7 0 ~ ~ . In 1976 I made an unselected and thorough investigation of all motor-handicapped children in the southernmost county-council area of Sweden (0 .5 million inhabitant^)^. The incidence of cerebral palsy was 1.9 per thousand livebirths and the prevalence rate was 1 8 per thousand. These are exactly the same figures as I found in an analagous study in the same area 10 years earlier4. This means that for two decades the prevalence rate for cerebral palsy in our part of Sweden has remained unchanged. It would seem, therefore, that differences in prevalence rates between countries may also occur within a particular country.