The prevalence of Down syndrome in County Galway

This is a retrospective survey of all cases of Down syndrome recorded between 1981 and 2000 to mothers resident in Co. Galway. The study compares the incidence of Down syndrome in both decades and examines the effects of changing demographics on incidence rates. The overall prevalence rate was 26.8/10,000 live births for the full period. Although there were 5119 fewer births in the 1991-2000 period, the prevalence was 29.8/10,000 compared to 24.1/10,000 in the previous decade. Despite the falling birth rates and fertility rates observed in our study between the two decades we found that the higher prevalence of Down syndrome in the second decade was directly related to the significant increase in the proportion of women in the 30 plus age group. Our study also found the place of the child with Down syndrome in the family changed, with 25.3% being the 5th or more child in the first decade compared with 9.5% in the second decade.     

Relationship of age and hypertension to neuropsychological test performance

Young adult (X = 29) and middle aged (X = 50) hypertensive and normotensive subjects were compared with respect to seven neuropsychological test scores derived from tests on the Halstead-Reitan battery. Age main effects, with inferior performance for the middle aged subjects, were observed for the localization and time portions of the Tactile Performance Test (TPT) and for the Trail Making A test. The multivariate age effect was significant for the composite of seven scores. A multivariate blood pressure main effect was obtained and main effect blood pressure was significant for the category test; hypertensives made more errors than normotensives. A blood pressure by age interaction was observed for finger tapping scores and the TPT-Memory scores with larger differences between hypertensives and normotensives for the younger than for the middle aged group. Results were discussed in terms of previous studies of age and hypertension with the WAIS, the Primary Mental Abilities Test and serial reaction time measures. The poor prediction of hypertensive status from individual neuropsychological test scores was emphasized and readers were cautioned not to conclude that essential hypertensives, as a group, can be characterized as brain damaged.