Down's syndrome, research and practice : the journal of the Sarah Duffen Centre最新文献

Immunological, endocrinological, and haematological abnormalities are relatively common in people with Down syndrome (Cuadrado & Barrena, 1996; Decoq & Vincker, 1995; Hestnes et al., 1991; Sustrova & Strbak, 1994; Nespoli, Burgio, Ugazio & Maccario, 1993; Kempski, Chessells & Reeves, 1997; Kivivuori, Rajantie, & Siimes, 1996; David et al., 1996; Gjertson, Sturm & Berger, 1999). Zinc is one of the elements that act in the maintenance of normal function of these systems. This study was designed to investigate zinc levels in children with Down syndrome. Zinc levels were measured in hair using atomic absorption spectrophotometry. The hair zinc level of 19 children with Down syndrome was compared with the zinc level of 11 typically developing children. Hair zinc levels were found to be significantly lower (p < .05) in those with Down syndrome (average 95.18 +/- 56.10 ppm) than in the typically developing children (average 208.88 +/- 152.37 ppm). Some of the problems experienced by children with Down syndrome may be due to these low zinc levels, but further research is required to confirm these results, and to establish any correlation with these problems.

The increase in life expectancy within the general population has resulted in an increasing number of elderly adults with intellectual disability, and this is reflected in the increased life expectancy in persons with Down syndrome, currently about 56 years. The aim of this study was to study the clinical characteristics, the functional status and sensori-motor function of 10 older persons with Down syndrome (mean age 59 years), 13 younger persons with Down syndrome (mean age 44 years) and compare them with 38 adults with intellectual disability without Down syndrome and a control group of people without intellectual disability. All the persons with Down syndrome and intellectual disability resided in two residential living centres in Israel, while the 31 older persons without intellectual disability (mean age 75 years), who served as the control group, lived in an independent living facility. The study considered demographic data, medical backgrounds, physical and functional tests. The results showed that the older persons with Down syndrome in the study were more obese, shorter and had more medical problems than both the older persons with intellectual disability and the control group. The functional performance of the older adults with Down syndrome was more impaired in comparison with both other groups. It is postulated that their slower responses may be explained by a less physically active lifestyle, that may accelerate the onset of disease, resulting in symptoms associated with aging that are detrimental to health.

This pilot study was designed to examine mental rotation ability in individuals with Down syndrome. 7 individuals with Down syndrome (mean mental age = 8.18 +/- 2.73 years; mean chronological age = 29.8 +/- 5.4 years) and a group of 9 typically developing children, matched for mental age, (mean mental age = 8.40 +/- 1.73 years; mean chronological age = 7.2 +/- 1.2 years) were given a version of Cooper and Shepherd's (1973) mental rotation paradigm. On each trial, participants viewed a symbol representing an upper case 'F' or a mirror image of an 'F'. The symbol was presented at one of eight different orientations. The participant's task was to determine whether the letter was reversed or non-reversed. Interestingly, both groups showed similar trends in increased reaction times with increasing angular disparity, suggesting that both groups were performing mental rotations. There was no significant difference in reaction time between the typically developing and Down syndrome groups, however, the Down syndrome group made significantly more errors than the typically developing group. Participants with Down syndrome were able to carry out the mental rotations at well above chance level and mental rotation ability was shown to correlate with mental age.

This study was undertaken to explore the use of a digital camera for mental imagery training of a vocational task with two young adult men with Down syndrome. The results indicate that these particular men benefited from the use of a collaborative training process that involved mental imagery for learning a series of photocopying operations. An outline of a mental imagery assessment method is provided along with a description of the training procedures that were used in the study. Mental imagery was taught and rehearsed by means of a Powerpoint computer presentation. Trainers and participants worked collaboratively to complete a task analysis and to take photos of each person performing the operations correctly. Through the use of self-modelling and feed forward, participants were able to learn from observing their own actions and, in particular, to learn from 'successes' that they have not yet had. On the basis of this pilot study, it is proposed that mental imagery training is an important new approach for collaborative training, especially for individuals whose language systems are not well developed. There is a need, however, for further investigation into the role of mental imagery as this relates to memory, self-regulation and metacognition.

Increasingly, children with Down syndrome receive literacy instruction with the expectation of acquiring functional reading skills. Unfortunately, little is known about the processes underlying literacy skills in this special population. Phonological awareness contributes to literacy development in typically developing children, however, there is inconclusive evidence about these skills in younger children with Down syndrome. 9 children with Down syndrome (5.6-8.10 years) participated in this investigation. Due to the paucity of standardised phonological awareness measures for children with special needs, in particular children with Down syndrome, a variety of tasks were adapted from the literature. The assessment battery examined the skills of phonological awareness, literacy, speech production, expressive language, hearing acuity, speech perception, and auditory-visual memory. The results suggest that children with Down syndrome are at risks for reading acquisition difficulties due to reduced phonological awareness skills. These deficits are in addition to delays caused by reduced cognitive skills. Only one of the participants was able to demonstrate rhyme awareness, which may have been due to task effects. Written word recognition ability was correlated with tests of phonemic awareness, and error analysis of the spelling and non-word reading tasks suggested grapheme-phoneme connections deficits. Further research is needed to determine the best methods of assessment and intervention for phonological awareness in children with Down syndrome.

A fifteen-year follow up of the linguistic and cognitive profile of a woman, named Françoise, with standard trisomy 21. She had been studied in considerable detail between 1987 and 1991 by Rondal (1995) and found to have exceptionally good language abilities in advance of regular cognitive abilities for a person with Down syndrome. Françoise's psychological functioning has been deteriorating relatively rapidly over the last two years. A severe deterioration of her previously excellent receptive language abilities is documented in the present study. Productively, her on-line word finding is becoming problematic, mean length of utterance has halved compared with 15 years ago, and production of compound sentences is reduced. However, basic phonological and morphosyntactic skills are preserved. Françoise's changing profile during the latter years seems to mirror that documented in the first stages of Alzheimer disease in ageing adults in the general population.

Background: While the prevalence of obstructive sleep apnoea syndrome among children with Down syndrome is reported to vary from 30 to 50%, the nocturnal respiratory patterns of adults with Down syndrome is not well known.

Objectives: The aim of this study is to evaluate sleep-related breathing disorders in a sample of adults with Down syndrome.

Methods: We studied the nocturnal respiratory patterns of 6 adults with Down syndrome, aged 28-53 years. All participants were monitored for 8 hours using a 12 channel polysomnograph. Respiratory events (apnoeic and hypopnoeic) were classified as obstructive or central, in relation to the presence or the absence of paradoxical breathing.

Results: All participants had respiratory pauses during sleep. 5 of them had an apnoea/hypopnoea index > 10, justifying the diagnosis of sleep apnoea syndrome. About 85% of the respiratory events were apnoeic, the others being hypopnoeic. Among all the respiratory events 89.2% were obstructive, whereas only 10.8% were central. The central events were almost always organised in very low and regular sequences and respiration frequently showed a true periodic pattern, consisting of short periods of augmented breath followed by central events causing oxygen desaturation.

Conclusions: According to the literature and in conjunction with the current study's results it could be hypothesised that the nocturnal respiratory pattern of adults with Down syndrome depends on several pathogenetic factors such as age, severity of upper airway abnormalities, body mass index (BMI), other pathological conditions and age-related brainstem dysfunction.

The purpose of this study was to examine the learning of movement sequences in individuals with Down syndrome under different visual information conditions. 10 adults with Down syndrome and 14 neurologically typical adults performed a sequence of movements under two different visual information conditions: full visual feedback of the limb and environment and no visual feedback of the limb. Participants were given knowledge of results of their total movement time after each trial. The entire task was presented as a game and movement time information was given as a "score" after each trial. Participants were also given verbal encouragement throughout the task. As expected, individuals with Down syndrome had significantly slower reaction and movement times than neurologically typical participants. Interestingly, however, mean reaction and movement time was not affected by the visual condition, in either group. Participants with Down syndrome improved their performance over the presented trials, in both visual information conditions. These findings indicate that providing knowledge of results of movement performance can facilitate the performance and coordination of movement sequences even under conditions where visual information of the moving limb is restricted.