RESUMEN
BACKGROUND: Down syndrome (DS) is associated with elevated rates of autism spectrum disorder (ASD) and autism symptomatology. To better characterise heterogeneity in ASD symptomatology in DS, profiles of caregiver-reported ASD symptoms were modelled for children and adolescents with DS. METHODS: Participants (n = 125) were recruited through several multi-site research studies on cognition and language in DS. Using the Social Responsiveness Scale-2 (SRS-2; Constantino and Gruber 2012), two latent profile analyses (LPA) were performed, one on the broad composite scores of social communication and interaction and restricted interests and repetitive behaviour, and a second on the four social dimensions of social communication, social motivation, social awareness, and social cognition. RESULTS: A three-profile model was the best fit for both analyses, with each analysis yielding a low ASD symptom profile, an elevated or mixed ASD symptom profile and a high ASD symptom profile. Associations were observed between profile probability scores and IQ, the number of co-occurring biomedical conditions reported, sex, and SRS-2 form. CONCLUSIONS: Characterising heterogeneity in ASD symptom profiles can inform more personalised supports in this population, and implications for potential therapeutic approaches for individuals with DS are discussed.
Asunto(s)
Trastorno del Espectro Autista , Trastorno Autístico , Síndrome de Down , Adolescente , Trastorno del Espectro Autista/complicaciones , Niño , Síndrome de Down/epidemiología , Humanos , MotivaciónRESUMEN
Recent studies have suggested that Boundary Extension (BE), a scene construction error, may be linked to the function of the hippocampus. In this study, we tested BE in two groups with variations in hippocampal development and disorder: a typically developing sample ranging from preschool to adolescence and individuals with Down syndrome. We assessed BE across three different test modalities: drawing, visual recognition, and a 3D scene boundary reconstruction task. Despite confirmed fluctuations in memory function measured through a neuropsychological assessment, the results showed consistent BE in all groups across test modalities, confirming the near universal nature of BE. These results indicate that BE is an essential function driven by a complex set of processes, that occur even in the face of delayed memory development and hippocampal dysfunction in special populations.
Asunto(s)
Síndrome de Down/fisiopatología , Hipocampo/fisiología , Memoria/fisiología , Percepción Visual/fisiología , Adolescente , Niño , Preescolar , Femenino , Hipocampo/crecimiento & desarrollo , Hipocampo/fisiopatología , Humanos , Masculino , Pruebas Neuropsicológicas , Adulto JovenRESUMEN
Event related potentials (ERPs) can help to determine the cognitive and neural processes underlying memory functions and are often used to study populations with severe memory impairment. In healthy adults, memory is typically assessed with active tasks, while in patient studies passive memory paradigms are generally used. In this study we examined whether active and passive continuous object recognition tasks measure the same underlying memory process in typically developing (TD) adults and in individuals with Down syndrome (DS), a population with known hippocampal impairment. We further explored how ERPs in these tasks relate to behavioral measures of memory. Data-driven analysis techniques revealed large differences in old-new effects in the active versus passive task in TD adults, but no difference between these tasks in DS. The group with DS required additional processing in the active task in comparison to the TD group in two ways. First, the old-new effect started 150 ms later. Second, more repetitions were required to show the old-new effect. In the group with DS, performance on a behavioral measure of object-location memory was related to ERP measures across both tasks. In total, our results suggest that active and passive ERP memory measures do not differ in DS and likely reflect the use of implicit memory, but not explicit processing, on both tasks. Our findings highlight the need for a greater understanding of the comparison between active and passive ERP paradigms before they are inferred to measure similar functions across populations (e.g., infants or intellectual disability).
Asunto(s)
Corteza Cerebral/fisiopatología , Síndrome de Down/fisiopatología , Potenciales Evocados , Reconocimiento Visual de Modelos/fisiología , Reconocimiento en Psicología/fisiología , Adolescente , Adulto , Electroencefalografía , Femenino , Humanos , Masculino , Pruebas Neuropsicológicas , Adulto JovenRESUMEN
The high prevalence of sleep disorders, particularly obstructive sleep apnea, is well established in children with Down syndrome. However, only a few studies have focused on older children and young adults in this population. Given the presence of sleep disorders and the early emergence of Alzheimer's disease, more work is needed to examine the relationship between sleep and cognition in Down syndrome. Twenty-nine adolescents and young adults with Down syndrome participated in the present study. Parents reported on their sleep difficulties using a well-validated measure of sleep problems in intellectual disabilities. Based on theoretical models linking obstructive sleep apnea to prefrontal cortex dysfunction, we tested components of executive functions that have been shown to be impaired in previous studies of Down syndrome. First, results indicate that participants with Down syndrome with higher body mass index also had increased caregiver reports of sleep apnea symptoms. Individuals with high ratings of sleep disruption also showed greater difficulties with executive function. These results suggest that sleep disruption may place this set of functions at risk in young adults. Future work should examine if this risk may result in earlier onset of dementia or steeper decline with Alzheimer's disease. Further, additional studies are needed to investigate the effect of exercise interventions and weight reduction on sleep disorders in this population.
Asunto(s)
Síndrome de Down/fisiopatología , Función Ejecutiva/fisiología , Trastornos del Sueño-Vigilia/fisiopatología , Adolescente , Adulto , Femenino , Humanos , Masculino , Pruebas Neuropsicológicas , Apnea Obstructiva del Sueño/fisiopatologíaRESUMEN
BACKGROUND: Children with Down syndrome (DS) suffer from sleep problems, including sleep maintenance problems, as well as snoring, and other symptoms of disordered breathing. To examine sleep in DS, we gave parents a questionnaire assessing their child's sleep. MATERIALS AND METHODS: The parents of 35 children with DS (mean age = 12.65 years, range = 7-18 years) completed the 33-item Children's Sleep Habits Questionnaire. RESULTS: Eighty-five per cent of our sample had sleep disturbance scores in the clinical range (mean = 48.63, SD = 7.15, range = 34-64). Our sample also had significantly elevated scores on the Bedtime Resistance, Sleep Anxiety, Night Wakings, Parasomnias, Sleep Disordered Breathing and Daytime Sleepiness subscales. CONCLUSIONS: Children with DS are at risk for developing symptoms of sleep disordered breathing, and may have additional sleep problems that are unrelated to sleep disordered breathing.
Asunto(s)
Síndrome de Down/epidemiología , Discapacidad Intelectual/epidemiología , Trastornos del Sueño-Vigilia/epidemiología , Adolescente , Ansiedad/epidemiología , Ansiedad/psicología , Niño , Síndrome de Down/psicología , Femenino , Humanos , Discapacidad Intelectual/psicología , Masculino , Parasomnias/epidemiología , Parasomnias/psicología , Padres , Factores de Riesgo , Síndromes de la Apnea del Sueño/epidemiología , Síndromes de la Apnea del Sueño/psicología , Trastornos del Sueño-Vigilia/psicología , Encuestas y CuestionariosRESUMEN
BACKGROUND: While it has been common practice to discourage second language learning in neurodevelopmental disorders involving language impairment, little is known about the effects of second language exposure (SLE) on broader cognitive function in these children. Past studies have not found differences on language tasks in children with Down syndrome (DS) and SLE. We expand on this work to determine the effects on the broader cognitive profile, including tests tapping deficits on neuropsychological measures of prefrontal and hippocampal function. METHOD: This study examined the specific cognitive effects of SLE in children with DS (aged 7-18 years). Children with SLE (n = 13: SLE predominantly Spanish) and children from monolingual homes (n = 28) were assessed on a standardised battery of neuropsychological tests developed for DS, the Arizona Cognitive Test Battery. The current exposure level to a language other than English in the SLE group was greater than 4 h per day on average. RESULTS: No group differences were observed for any outcome, and level of exposure was also not linearly related to neuropsychological outcomes, several of which have been shown to be impaired in past work. CONCLUSION: There were no measurable effects of SLE on neuropsychological function in this sample of children with DS. Potential clinical implications of these findings are discussed.