Hithersay, Rosalyn;
(2019)
Ageing in Down syndrome: Exploring executive functioning and frontal cortical activity using functional near infrared spectroscopy.
Doctoral thesis (Ph.D), UCL (University College London).
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Abstract
Adults with Down syndrome (DS) are at exceptionally high risk of developing early-onset dementia due to near universal Alzheimer’s disease (AD) neuropathology from age 35. Executive functioning (EF) decline may be an early dementia marker in DS. However, a paucity of functional neuroimaging in DS research limits our understanding of brain function and its relationship with EF performance at all ages. This knowledge gap may reflect difficulties administering neuroimaging protocols using restrictive modalities such as functional magnetic resonance imaging (fMRI). Functional near infrared spectroscopy (fNIRS) is an emerging cortical neuroimaging modality that is less restrictive than fMRI, thus may offer new opportunities for neuroimaging in people with DS. Four studies examined the feasibility of using fNIRS to measure EF-related frontal cortical activity in adults with DS. In study 1, 5 adults with DS and 5 carers discussed fNIRS alongside facilitators and barriers to neuroimaging research participation. Studies 2 (n=12 adults without DS) and 3 (n=9 adults with DS) assessed initial feasibility with four EF tasks: a go / no-go (GNG), a verbal fluency (VFT), a dimensional change card sort (DCCS) and a novel computerised picture-Stroop task. Study 4 examined task performance and haemodynamic responses in the GNG, VFT and Stroop tasks in 46 adults with DS, aged 18-59. 94% of participants with DS completed an fNIRS scan. The GNG, VFT and Stroop were widely accessible, with the latter two tasks showing consistent haemodynamic responses across studies. Peak oxy-haemoglobin concentration during Stroop interference in left inferior frontal / superior temporal regions decreased significantly with increasing age, and this task showed potential sensitivity to performance decline in early dementia stages. fNIRS is an extremely well-tolerated neuroimaging technique, which when combined with sensitive EF measures, can be used to examine age-related changes in brain function in people with DS.
| Type: | Thesis (Doctoral) |
|---|---|
| Qualification: | Ph.D |
| Title: | Ageing in Down syndrome: Exploring executive functioning and frontal cortical activity using functional near infrared spectroscopy |
| Event: | UCL (University College London) |
| Open access status: | An open access version is available from UCL Discovery |
| Language: | English |
| Additional information: | Copyright © The Author 2019. Original content in this thesis is licensed under the terms of the Creative Commons Attribution 4.0 International (CC BY 4.0) Licence (https://creativecommons.org/licenses/by/4.0/). Any third-party copyright material present remains the property of its respective owner(s) and is licensed under its existing terms. Access may initially be restricted at the author’s request. |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Brain Sciences |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10076691 |
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