One year of health and social services for adolescents with Down's syndrome

Summary The costs of the public health and social security system supporting adolescents 14–20 years old with Down's syndrome (DS) over 1 year (1985) were investigated in the county of Aarhus, representing about 10% of the Danish population. Seventy-eight percent of the probands lived in private homes; the rest were institutionalized. No controls lived in an institution. The average yearly price of a DS adolescent living in a private home was Dkr 217,194 (US$ 24,213 or Br.£ 6,811). If the DS individual was institutionalized, the amount was Dkr 383,271 (US$ 42,728 or Br.£ 29,665). The average yearly price for a control was: Dkr 33,352 (US$ 3,718 or Br.£ 2,581).     

Olfactory function in young adolescents with Down's syndrome.

Decreased ability to smell is present in adults with Down's syndrome, many of whom are known to have brain pathology analogous to that seen in Alzheimer's disease. Because olfactory loss is well documented in Alzheimer's disease, the question arises whether young adolescents with Down's syndrome, who have no clear Alzheimer's disease-like neuropathology, also exhibit olfactory dysfunction. To consider this issue, standardised tests of odour discrimination and identification were administered to 20 young adolescents with Down's syndrome (mean age (SD) 13.89 (1.98) years) and their test scores were compared with 20 mentally retarded and 20 non-mentally retarded control subjects matched to the patients with Down's syndrome on the basis of cognitive ability. No significant differences in olfactory function were found among the three study groups. These findings, along with those from studies of olfactory function in older patients with Down's syndrome, suggest that Down's syndrome related olfactory dysfunction occurs only at ages when Alzheimer's disease-like pathology is present.     

Cognitive functions in adult Down's syndrome

Cognitive profiles of performances were obtained from a selected group of adult Down syndrome (DS) subjects (n = 20; mean age: 34.5 years; s.d.: 7.7) by means of an ad hoc neuropsychological battery. With the aim of examining, from a neuropsychological point of view, the modifications that increasing age produces in this group of patients, cognitive performances of younger DS subjects (mean age: 28 years; s.d.: 4.77) were compared with analogous performances obtained by the older ones (mean age: 39.8 years; s.d.: 5.11). Subsequently, to clarify qualitative aspects of cognitive patterns in the subgroups of young and old DS subjects, two different groups of control patients were utilised. Neuropsychological data collected from a group of adult mentally retarded subjects were compared with cognitive performances demonstrated by young DS subjects, while the old group of DS subjects was analyzed in comparison with a group of patients affected by initial form of Alzheimer disease (AD). Altogether, the results of our study do not seem to support, from a neuropsychological point of view, the hypothesis that mental decline observed in DS subjects reproduces the cognitive patterns of impairment observed in AD patients.     

Neocerebellar contributions to social perception in adolescents with autism spectrum disorder

Posterior superior temporal sulcus (pSTS) is specialized for interpreting perceived human actions, and disruptions to its function occur in autism spectrum disorder (ASD). Here we consider the role of Crus I of neocerebellum in supporting pSTS function. Research has associated Crus I activity with imitation and biological motion perception, and neocerebellum is theorized to coordinate activity among cerebral sites more generally. Moreover, cerebellar abnormalities have been associated with ASD. We hypothesized that disordered Crus I–pSTS interactions could predict social deficits in ASD. 15 high functioning adolescents with ASD and 15 same-age comparison youth participated in an fMRI imitation paradigm; ratings of mentalizing ability were collected via parent report. We predicted that stronger Crus I–pSTS interactions would be associated with better mentalizing ability. Consistent with these hypotheses, stronger psychophysiological interactions between Crus I and right pSTS were associated with greater mentalizing ability among adolescents with ASD. Whole-brain analyses also indicated that typically developing youth recruited right inferior frontal gyrus, left pSTS, medial occipital regions, and precuneus more strongly during imitation than did youth with ASD. Overall, these results indicate that variability in neocerebellar interactions with key cortical social brain sites may help explain individual differences in social perceptual outcomes in ASD.     

Sexual,social, and emotional development in people with Down's syndrome*

This article reviews the literature concerning the sexual development of people with Down's syndrome and considers the interplay of factors affecting their social and emotional development. The need for appropriate sociosexual education and training is discussed.     

Sentence imitation by adolescents and young adults with Down's syndrome and other intellectual disabilities

Sentence imitation performance was evaluated longitudinally in 26 adolescents and young adults with Down's syndrome (DS), and 26 age- and IQ-matched non-DS individuals with other causes of intellectual disability (ID). In each of three annual assessments, the DS group began sentence repetitions more slowly and imitated sentences less accurately than the ID group. DS sentence repetition accuracy was equivalent to the ID group only for two-word sentences and was poorer for every other sentence length. Comparisons of sentence imitation and auditory digit span scores suggested that only ID subjects benefitted from the additional meaning and structure provided by sentences. Correlational analyses performed between each year's sentence imitation score and a set of language, memory and hearing measures revealed that sentence imitation was related to grammatical comprehension, auditory short-term memory and IQ in both groups, and to expressive language ability, speed of spoken word processing, speech discrimination and acoustic reflexes in the DS group only. A significant relationship between sentence imitation and middle-ear functioning was further supported by a categorical analysis in which DS subjects with bilateral abnormal tympanograms tended to perform more poorly on sentence imitation tasks than DS subjects with at least one normal tympanogram. It was concluded that sentence imitation is a task that is sensitive to the auditory-perceptual, cognitive and expressive difficulties evidenced by individuals with DS.     

Visual-spatial processing in children and adolescents with Down's syndrome: a computerized assessment of memory skills

Background Several studies have identified better visual‐spatial than verbal memory skills in children with Down's syndrome (DS); however, research in both typical development and DS points to a relative dissociation between visual and spatial memory processing, questioning the notion of a unitary visual‐spatial memory construct. The insufficient and often contradictory results regarding the visual‐spatial memory domain probably reflect the heterogeneity of memory tests employed by these studies and the different memory systems that they evaluate. Method We administered five visual‐spatial memory tasks from the Cambridge Neuropsychological Test Automated Battery (CANTAB) to 25 children with DS and to 25 controls matched for mental age (MA) and basic psychomotor speed and accuracy. The memory tasks measure spatial span, visual and spatial recognition, paired associates learning and self‐ordered search abilities. Results The results confirm the relative sparing of the spatial short‐term memory (STM) capacity in children with DS; however, as memory load increases, in recognition tasks, or when visual and spatial demands are combined, their performance is impaired compared with MA controls. The same impairment is generated by additional executive demands in the self‐ordered search task, although search strategy is similar to the one presented by MA controls. Conclusions We did not find support for a visual vs. spatial dissociation in recognition memory. Performance impairment in the visual‐spatial domain parallels the increase in working memory (WM) load or in the executive demands of the task. Possible neurobiological implications of the observed performance on the CANTAB tasks are also considered.     

Hypercarotenaemia in children with Down's syndrome

ABSTRACT. In previous reports, deficiencies in serum vitamin A were considered a frequent finding in persons with Down's syndrome. Based on this assumption, the regular determination of both serum carotene and vitamin A has been recommended for the preventive care of this population. In the author's preventive medicine clinic for children with Down's syndrome, we have checked these items routinely in 44 fasting patients (aged 14 months to 19 years). The author was surprised to find no patient with either a deficiency of carotene or vitamin A, but 14 patients had hypercarotenemia. Any known aetiology of this finding, such as excessive ingestion, diabetes mellitus or hypothyroidism, could not be verified. It has to be mentioned that the previous reports on serum carotene levels were based on determinations by conventional spectrophoto-metric methods (normal range: 50-670 μg/dl), whereas the author applied an improved method of high-performance liquid chromatography with a much lower normal range (50-750 μg/l). Further investigations are to be performed to verify these findings and to evaluate probable mechanisms of hypercarotenemia in persons with Down's syndrome.     

Lipids and lipoproteins in persons with Down's syndrome

ABSTRACT. This study was designed to investigate whether the observed decreased prevalence of coronary artery disease in individuals with Down's syndrome may be explained by their serum lipid and lipoprotein profiles. Twentyseven persons with Down's syndrome and 23 non-afiFected control individuals were enrolled in this study. Their fasting venous blood was analysed for total cholesterol, triglyceride, LDH cholesterol, HDL cholesterol, apo B and apo AI. The results revealed no significant differences between the study and control group with regard to total cholesterol, LDL cholesterol, apo B and the apo B:apo AI ratio. However, triglyceride levels were significantly increased, and serum HDL cholesterol, apo AI and HDL cholesterohtotal cholesterol ratio were significantly decreased in patients with Down's syndrome when compared with the control group. The latter observations are all associated with an increased risk for coronary artery disease. Therefore, it is concluded that the decreased prevalence of coronary artery disease in individuals with Down's syndrome carmot be explained by the lipid and lipoprotein levels observed in this study population.     

Dementia and mortality in persons with Down's syndrome

Background Numerous studies have documented that persons with Down’s syndrome (DS) are at an increased risk of Alzheimer’s disease (AD). However, at present it is still not clear whether or not all persons with DS will develop dementia as they reach old age. Methods We studied 506 people with DS, aged 45 years and above. A standardized assessment of cognitive, functional and physical status was repeated annually. If deterioration occurred, the patients were examined and the differential diagnosis of dementia was made according to the revised Dutch consensus protocol and according to the ICD‐10 Symptom Checklist for Mental Disorders. We compared our findings with those reported in the literature. Results The overall prevalence of dementia was 16.8%. Up to the age of 60, the prevalence of dementia doubled with each 5‐year interval. Up to the age of 49, the prevalence is 8.9%, from 50 to 54, it is 17.7%, and from 55 to 59, it is 32.1%. In the age category of 60 and above, there is a small decrease in prevalence of dementia to 25.6%. The lack of increase after the age of 60 may be explained by the increased mortality among elderly demented DS patients (44.4%) in comparison with non‐demented patients (10.7%) who we observed during a 3.3‐year follow‐up. There was no decrease in incidence of dementia in the age group of 60 and above. Our findings are very similar to those published in the literature. Patients with dementia were more frequently treated with antiepileptic, antipsychotic and antidepressant drugs. The history of depression was strongly associated with dementia. Conclusions Our study is one of the largest population‐based studies to date. We found that despite the exponential increase in prevalence with age, the prevalence of dementia in the oldest persons with DS was not higher than 25.6%.     

Biochemical changes and catecholamine responses in Down's syndrome adolescents in relation to incremental maximal exercise

ABSTRACT. The aim of this study was to determine biological responses in Down's syndrome subjects for an incremental exercise lasting 10 min. After a training programme specially adapted for children and adolescents with mental handicaps, 11 healthy Down's syndrome subjects, seven boys and four girls aged from 15 to 20 years, performed a progressive exercise until exhaustion on an ergometric bicycle. The results were compared with those taken from the literature for similar aged normal subjects. The results in our series of Down's syndrome subjects showed: (a) no differences in haematologic parameters, except for a high concentration of uric acid at rest which did not increase after the test; (b) a lower blood lactate level than in maximal exercise for this age range; (c) a late mobilization of FFA; and (d) a slightly lower maximal value of catecholamines. These results may suggest a reduced sympathetic response to maximal exercise.     

Facial emotion perception by intensity in children and adolescents with 22q11.2 deletion syndrome

Difficulties in the recognition of emotions in expressive faces have been reported in people with 22q11.2 deletion syndrome (22q11.2DS). However, while low-intensity expressive faces are frequent in everyday life, nothing is known about their ability to perceive facial emotions depending on the intensity of expression. Through a visual matching task, children and adolescents with 22q11.2DS as well as gender- and age-matched healthy participants were asked to categorise the emotion of a target face among six possible expressions. Static pictures of morphs between neutrality and expressions were used to parametrically manipulate the intensity of the target face. In comparison to healthy controls, results showed higher perception thresholds (i.e. a more intense expression is needed to perceive the emotion) and lower accuracy for the most expressive faces indicating reduced categorisation abilities in the 22q11.2DS group. The number of intrusions (i.e. each time an emotion is perceived as another one) and a more gradual perception performance indicated smooth boundaries between emotional categories. Correlational analyses with neuropsychological and clinical measures suggested that reduced visual skills may be associated with impaired categorisation of facial emotions. Overall, the present study indicates greater difficulties for children and adolescents with 22q11.2DS to perceive an emotion in low-intensity expressive faces. This disability is subtended by emotional categories that are not sharply organised. It also suggests that these difficulties may be associated with impaired visual cognition, a hallmark of the cognitive deficits observed in the syndrome. These data yield promising tracks for future experimental and clinical investigations.     

Speech disorder in children with Down's syndrome

The speech of children with Down's syndrome (DS) is often unintelligible, unlike many other children who have an intellectual disability. However, the nature of their speech disorder is controversial. The speech error patterns of children with DS were compared to those of intellectually average chil‐dren with phonological disorder whose errors were characterized by inconsistency. The groups were matched for percentages of consonants produced in error. The data revealed no differences between the groups in terms of the number of words which were produced inconsistently on repeated productions in a picture‐naming task. However, further analyses revealed differences in the type of errors made by the groups in that the children with phonological disorder characterized by inconsistent errors made more changes to words on repeated production than the group with DS. The deficits underlying inconsistent pronunciation of words in the two groups of children under investigation would appear to differ. Intervention strategies should target the deficits identified.     

Dementia in people with Down's syndrome.

OBJECTIVES: To determine the prevalence of dementia in an Irish sample of people with Down's syndrome (DS) and to examine associated clinical characteristics of dementia in this group. METHOD: 285 people with DS (Age 35-74 years, mean age +/- SD 46.5 +/- 8.2 years) were included in this cross-sectional study. The diagnosis of dementia was made using modified DSMIV criteria. Cognitive tests used were the Down's syndrome Mental Status Examination (DSMSE), Test for Severe Impairment (TSI) and adaptive function was measured by the Daily Living Skills Questionnaire (DLSQ). RESULTS: The overall prevalence of dementia was 13.3%. The presence of dementia was associated with epilepsy, myoclonus, and head injury. The demented DS group were significantly older (n = 38, mean age 54.7 years SD +/- 7.5) than the non-demented (n = 246, mean age 45.6, SD +/- 7.3). The TSI and DLSQ had a satisfactory spread of scores without 'floor' or 'ceiling' effects in people with moderate and severe learning disability. Median scores in demented versus the non-demented groups were significantly different for each measure of function. CONCLUSIONS: Dementia had a prevalence of 13.3% and occurred at a mean age of 54.7 years. The combination of DLSQ score, age and presence of epilepsy were found to predict presence of dementia.