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Background Many studies have evaluated the prevalence of intellectual disability (ID) by focusing on different ages during childhood and adolescence. Although the prevalence of ID is higher in older age groups, how cumulative prevalence increases, and what level it reaches before adulthood, remains unclear. Method We used Care Register for Health Care to retrieve information on individuals born in 1996-2007 with any of the inclusion diagnoses of ID (F7 group and/or aetiological diagnoses) for the period 1996 to 2013. The cumulative prevalence was calculated as percentages for every age based on Finnish population data. Results The registration of new diagnoses of ID continued steadily throughout the developmental years. The cumulative prevalence reached 1.19% by age 17.5 among those born in 1996. Later-born age groups appeared to receive their first ID diagnoses earlier in childhood. Those born in 1999 reached a cumulative prevalence of 1.21% already by age 14.5. Of all those with ID, 67% had an F7 diagnosis only, 42% had an aetiological diagnosis only and 9% had both diagnoses. Conclusions Cumulative prevalence of ID by year, until the age of 18, will provide a better estimate and understanding of the prevalence of ID than a point prevalence at any one point during the developmental years. [ABSTRACT FROM AUTHOR]

Background Little is known about the mortality of individuals with Down syndrome who have lived at home with their families throughout their lives. The current study evaluates the predictors, causes and patterns of mortality among co-residing individuals in midlife with Down syndrome as compared with co-residing individuals with ID owing to other causes. Method This paper examines mortality in 169 individuals with and 292 individuals without Down syndrome from 1988 to 2007. Dates and causes of death were obtained from maternal report, the Social Security Death Index and the National Death Index. Risk factors predicting mortality, including demographic variables, transition variables, and initial and change measures of health, functional abilities and behaviour problems, were obtained from maternal report. Results Having Down syndrome is a risk factor of mortality, net of other risk factors including older age, poorer functional abilities, worsening behaviour problems, residential relocation and parental death. The causes of death among individuals with and without Down syndrome who are in midlife and co-residing with their families are similar, and are most commonly due to cardiovascular or respiratory problems. Conclusions The findings indicate that midlife adults with Down syndrome who co-reside with their families generally exhibit similar causes of mortality as do midlife adults with intellectual disability owing to other causes, but show an elevated risk of mortality in midlife net of other variables, such as age and changes in functional abilities and behaviour problems. [ABSTRACT FROM AUTHOR]

In the last few years, experimental data have been reported on differences in implicit memory processes of genetically distinct groups of individuals with Intellectual Disability (ID). These evidences are relevant for the more general debate on supposed asynchrony of cognitive maturation in children with abnormal brain development. This study, comparing implicit memory processes in individuals with Williams syndrome (WS) and Down syndrome (DS), was planned to verify the ‘etiological specificity' hypotheses pertaining to the skill learning abilities of individuals with ID. A modified version of Nissen and Bullemer's (1987) Serial Reaction Time (SRT) task was used. The performances of three group were evaluated. The first group consisted of thirty-two people with WS (18 males and 14 females). The second group was comprised of twenty-six individuals with DS (14 males and 12 females). The two groups of individuals with ID were selected so that the groups were comparable as for mental age and chronological age. The third group consisted of forty-nine typically developed children with a mental age similar to that of the groups with WS and DS. The two groups of individuals with ID demonstrated different patterns of procedural learning. WS individuals revealed poor implicit learning of the temporal sequence of events characterizing the ordered blocks in the SRT task. Indeed, differently from normal controls, WS participants showed no reaction time (RT) speeding through ordered blocks. Most importantly, the rebound effect, which so dramatically affected normal children's RTs passing from the last ordered to the last block, had only a marginal influence on WS children's RTs. Differently from the WS group, the rate of procedural learning of the participants with DS was comparable to that of their controls. Indeed, DS and typically developed individuals showed parallel RT variations in the series of ordered blocks and, more importantly, passing from the last ordered to [ABSTRACT FROM AUTHOR]

Background This preliminary study served as a pilot for an ongoing analysis of spectral power in adults with Down syndrome (DS) using a 151 channel whole head magnetoencephalography (MEG). The present study is the first step for examining and comparing cortical responses during spontaneous and task related activity in DS. Method Cortical responses were recorded with a 151 channel whole head MEG system in three adults with DS and three age-matched adults without DS. MEG data were obtained at rest with eyes open and during observation of point-light displays of human motion and object motion. Data from both groups were evaluated by spectral analysis. Results The preliminary results showed greater alpha (8–14 Hz) power particularly in the occipital and parietal areas during the eyes open condition in the adults with DS in relation to a normal comparison group. The visual task had little effect on alpha power in the comparison group. Engaging in the visual task reduced power in alpha across all regions in the DS group to the level observed in comparisons. In the gamma band (30–50 Hz), power values were similar across both groups for the eyes open condition. In the comparison group, large reductions in gamma were observed in the occipital and bilateral temporal areas during the visual task. This change was not observed in the DS group. Conclusions The results from this pilot study suggest that MEG may be useful in characterizing task-specific changes in cortical activity in individuals with DS. Future studies with a larger group of individuals will further contribute to our understanding of the neurophysiology of Down syndrome. [ABSTRACT FROM AUTHOR]

Persons with Down syndrome are frequently described as ‘clumsy’. The recent progress in the development of quantitative approaches to motor synergies has allowed researchers to move towards an understanding of ‘clumsiness’ at the level of underlying control mechanisms. This progress has also offered an opportunity to quantify changes in motor synergies that accompany improvement in the performance of motor tasks. Previous studies of our group have shown, in particular, that persons both with and without Down syndrome are able to show improvements in indices of their multi-finger synergies in tasks that require accurate production of finger forces. In particular, 3 days of practice has been shown to lead to significant improvements in indices of multi-finger synergies that stabilize the time patterns of the total force produced by the fingers of a hand. Persons with Down syndrome showed a qualitative change in their synergies that failed to stabilize the total force altogether prior to practice and became able to do so after practice. In addition, the studies have also shown that variable practice is more beneficial for the improvement of motor synergies than blocked practice. I would like to draw an optimistic conclusion that persons with Down syndrome are not inherently ‘clumsy’, but have a vast potential for an improvement of their motor performance. The current state of the area of motor control allows researchers and practitioners to tap into these reserves, and to use quantitative indices of changes in motor synergies with practice to optimize motor performance of these individuals. [ABSTRACT FROM AUTHOR]