Research Collection Doctoral Thesis Interactive Cognitive-Motor Training in older Adults – The Extra Boost for Cognitive Performance and Brain Function? Author(s): Eggenberger, Patrick Publication Date: 2017 Permanent Link: https://doi.org/10.3929/ethz-b-000246161 Rights / License: Creative Commons Attribution 4.0 International This page was generated automatically upon download from the ETH Zurich Research Collection. For more information please consult the Terms of use. ETH Library DISS. ETH NO. 24680 INTERACTIVE COGNITIVE–MOTOR TRAINING IN OLDER ADULTS – THE EXTRA BOOST FOR COGNITIVE PERFORMANCE AND BRAIN FUNCTION? A thesis submitted to attain the degree of DOCTOR OF SCIENCES of ETH ZURICH (Dr. sc. ETH Zurich) presented by PATRICK EGGENBERGER Dipl. Natw. ETH born on 04.06.1974 citizen of Grabs SG, Switzerland accepted on the recommendation of Prof. Dr. Eling D. de Bruin, ETH Zurich Prof. Dr. Nicole Wenderoth, ETH Zurich Prof. Dr. Jorunn L. Helbostad, NTNU Trondheim, Norway 2017 2 TABLE OF CONTENTS 1 Summary, Zusammenfassung 5 2 Thesis introduction 11 3 Gait speed in older adults (study 1) 27 4 Cognitive performance adaptations (study 2a) 51 5 Gait & physical performance adaptations (study 2b) 79 6 Brain functional adaptations (study 3) 119 7 Thesis conclusions 153 8 References 161 9 Acknowledgments 185 3 4 1 Summary, Zusammenfassung 5 1.1 SUMMARY Emerging evidence indicates that age-related decline in higher order cogni- tive processing, e.g. attention and executive functioning, is associated with impaired gait and is important in relation to falls in older adults (Yogev-Selig- mann et al., 2008; de Bruin and Schmidt, 2010; Mirelman et al., 2012). There are strong indications that the most important risk factors for cognitive de- cline, dementia, impaired gait, and falls in older adults are interconnected and are modifiable through physical activity and training as well as partly through cognitive training (Stenhagen et al., 2013; Baumgart et al., 2015; Hortobagyi et al., 2015; Van Abbema et al., 2015; Liu et al., 2016). However, since to date, to the best of our knowledge, no interventions have studied syn- ergistic or cumulative effects from multicomponent physical exercise pro- grams with additional cognitive training to improve cognitive performance, brain function, gait, and prevent falls. Moreover, the neurophysiological mechanisms mediating the effects of physical training on cognition and brain function in older adults remain unclear. Therefore, the aim of this thesis is to illuminate the effects of interactive sim- ultaneous cognitive–motor training modalities on cognitive and brain func- tion, cognitive–motor dual-task walking, and fall prevention in older adults. Study 1 (chapter 3) addresses the question of how good the cognitive and physical fitness status of Swiss older adults, as assessed with cognitive–motor dual-task gait speed measurements, is in relation to the requirements that are necessary to stay independent as a pedestrian in an urban environment. This cross-sectional study with 120 participants establishes the relevance of investigating effective training interventions for older adults, which are in the focus of the subsequent interventional studies 2a/b and 3. Thus, as a sec- ond step, a 6-month longitudinal training intervention study with a 1-year follow-up is performed, including 89 participants, to investigate both broad cognitive (study 2a, chapter 4) and physical adaptations, including dual-task gait measures and fall frequency (study 2b, chapter 5). Finally, in a third step, a shorter 8 weeks lasting training intervention study is conducted, in- cluding 42 participants, to address the question if the training-induced cog- nitive behavioral adaptations, that were observed in study 2a, would be re- flected in brain functional adaptations in older adults (study 3, chapter 6). 6 The main findings from study 1 include that about every third (35.6%) older person at the age of 70–79 years and almost three-quarters (73.8%) of persons ≥80 years cannot walk faster than 1.2 m/s, which is required to cross streets safely within the green–yellow phase of pedestrian lights, under cognitively challenging conditions. Study 2a demonstrates, first, that the two interactive simultaneous cognitive–motor programs are partially advantageous to boost performance in two measures of executive function (switching attention and working memory) compared to an exclusively physical training program; and second, that cognitive performance, including executive functions, long-term visual memory (episodic memory), and processing speed, is maintained until 1-year follow-up after all three interventions. Study 2b shows, first, that the two interactive simultaneous cognitive–motor programs result in a signifi- cant advantage in dual-task costs of walking compared to the exclusively physical program but not in any other gait variables; second, that the two simultaneous cognitive–motor interventions lead to different training-spe- cific adaptations in the rhythm and variability domains of gait; and third, that each of the three training programs very effectively reduced fall fre- quency for ~77%. Finally, Study 3 reports, first, that both the video game dancing and the balance interventions reduce left and right hemispheric pre- frontal cortex (PFC) oxygenation during the acceleration of walking, while video game dancing showed a larger reduction at the end of the walking phase compared to balance training in the left PFC; and second, that the exercise training-induced modulations in PFC oxygenation are associated with im- proved executive functions. The main conclusions from this thesis imply that the fitness status of many older adults is not appropriate to safely encounter the requirements for pe- destrians in urban areas, which reinforces the need for regular cognitive and physical training in the older population (study 1). Interactive simultaneous cognitive–motor training should be integrated in training programs aiming to improve cognition, gait performance, physical functioning, and reduce fall frequency in older persons. Such programs may potentially counteract the large prevalence of cognitive and gait impairments, as well as reduce fall fre- quency, inherently leading to more independence and a better quality of life (studies 2a/b). Finally, training-induced brain functional adaptations in the PFC seem to reduce the need of prefrontal resources of executive function and attention involved in challenging treadmill walking. This effect may liberate 7 cognitive resources to focus on other processes while walking in attention de- manding real-life situations such as crossing streets or walking while talking and could potentially reduce the risk of falling (study 3). 1.2 ZUSAMMENFASSUNG Neuere Forschungsergebnisse zeigen, dass die altersbedingte Abnahme von höheren kognitiven Prozessen, wie Aufmerksamkeit und exekutive Funktio- nen, mit Beeinträchtigungen des Gehens zusammenhängt und eine wichtige Rolle spielt bei Stürzen von älteren Erwachsenen (Yogev-Seligmann et al., 2008; de Bruin and Schmidt, 2010; Mirelman et al., 2012). Es gibt klare Hin- weise dafür, dass die wichtigsten Risikofaktoren für abnehmende kognitive Fähigkeiten, Demenz, Gangstörungen und Stürze bei älteren Erwachsenen in Verbindung zu einander stehen und zudem durch körperliche Aktivität und körperliches Training, sowie teilweise auch durch kognitives Training, modifizierbar sind (Stenhagen et al., 2013; Baumgart et al., 2015; Hortobagyi et al., 2015; Van Abbema et al., 2015; Liu et al., 2016). Dennoch haben unse- res Wissens bis heute keine Studien die synergistischen und kumulativen Ef- fekte von körperlichen Multikomponenten-Trainings-programmen, ergänzt mit kognitivem Training, hinsichtlich Verbesserungen der kognitiven Leis- tungsfähigkeit, der Hirnfunktion, des Ganges und der Sturzprävention un- tersucht. Zudem sind die neurophysiologischen Mechanismen ungeklärt wel- che die Effekte von körperlichem Training auf Kognition und Hirnfunktion bei älteren Erwachsenen verursachen. Das Ziel dieser Doktorarbeit ist es deshalb, die Effekte von interaktiven, si- multanen kognitiv–motorischen Trainingsformen auf die kognitiven Fähig- keiten, die Hirnfunktion, das Gehen mit kognitiv–motorischer Doppelaufgabe und die Sturzprävention bei älteren Erwachsenen zu beleuchten. In Studie 1 (Kapitel 3) wird der Frage nachgegangen wie gut die kognitive und körper- liche Fitness von älteren Schweizerinnen und Schweizern ist, bezüglich den Anforderungen welche notwendig sind um als Fussgänger in einem städti- schen Umfeld unabhängig zu bleiben. Als Parameter der kognitiven und kör- perlichen Fitness wird dazu die Gehgeschwindigkeit bei einer kognitiv–mo- torischen Doppelaufgabe erhoben. Diese Querschnittsstudie mit 120 8 Teilnehmern liefert die Begründung dafür weshalb es von grosser Relevanz ist, effektive Trainingsinterventionen für ältere Erwachsene zu erforschen, welche bei den nachfolgenden Interventionsstudien 2a/b und 3 im Fokus ste- hen. Als zweiter Schritt wird somit eine 6-monatige Trainings-Interventions- studie durchgeführt, welche eine Nachfolgeuntersuchung nach einem Jahr beinhaltet. Anhand von 89 Teilnehmern werden dabei umfassende kognitive (Studie 2a, Kapitel 4) und körperliche Anpassungen untersucht, inklusive Messungen des Gehens mit kognitiv–motorischer Doppelaufgabe und Sturz- häufigkeit (Studie 2b, Kapitel 5). Schliesslich wird in einem dritten Schritt eine kürzere 8-wöchige Trainings-Interventionsstudie mit 42 Teilnehmern durchgeführt. Damit