Dual-task related frontal cerebral blood flow changes in older adults with mild cognitive impairment: A functional diffuse correlation spectroscopy study

Cerebral blood flow; Mild cognitive impairment; SpectroscopyFlux sanguini cerebral; Deteriorament cognitiu lleu; EspectroscòpiaFlujo sanguíneo cerebral; Deterioro cognitivo leve; EspectroscopiaIntroduction: In a worldwide aging population with a high prevalence of motor and cognitive impairment, it is paramount to improve knowledge about underlying mechanisms of motor and cognitive function and their interplay in the aging processes. Methods: We measured prefrontal cerebral blood flow (CBF) using functional diffuse correlation spectroscopy during motor and dual-task. We aimed to compare CBF changes among 49 older adults with and without mild cognitive impairment (MCI) during a dual-task paradigm (normal walk, 2- forward count walk, 3-backward count walk, obstacle negotiation, and heel tapping). Participants with MCI walked slower during the normal walk and obstacle negotiation compared to participants with normal cognition (NC), while gait speed during counting conditions was not different between the groups, therefore the dual-task cost was higher for participants with NC. We built a linear mixed effects model with CBF measures from the right and left prefrontal cortex. Results: MCI (n = 34) showed a higher increase in CBF from the normal walk to the 2-forward count walk (estimate = 0.34, 95% CI [0.02, 0.66], p = 0.03) compared to participants with NC, related to a right- sided activation. Both groups showed a higher CBF during the 3-backward count walk compared to the normal walk, while only among MCI, CFB was higher during the 2-forward count walk. Discussion: Our findings suggest a differential prefrontal hemodynamic pattern in older adults with MCI compared to their NC counterparts during the dual-task performance, possibly as a response to increasing attentional demand.This work was supported by the Instituto de Salud Carlos III (MEDPHOTAGE, DTS 16/00099 and DTS 16/00087, 2017, and FRONT STAGE, PI 19/00734, 2020) and co-funded by European Regional Development Fund/European Social Fund “Investing in your future,” the European Union’s Horizon 2020 Research and Innovation Program under the Marie Skłodowska-Curie (Grant No. 713729), Fundació CELLEX Barcelona, Fundació Mir-Puig, Agencia Estatal de Investigación (PHOTOMETABO, PID2019-106481RB-C31/10.13039/501100011033), FEDER EC and LASERLAB-EUROPE V (EC H2020 number 871124) and “Severo Ochoa” Programme for Centres of Excellence in R&D (CEX2019-000910-S)

Effect of a multicomponent exercise program and cognitive stimulation (VIVIFRAIL-COGN) on falls in frail community older persons with high risk of falls: study protocol for a randomized multicenter control trial

Cognitive function; Falls; FracturesFunción cognitiva; Caídas; FracturasFunció cognitiva; Caigudes; FracturesBackground Falls represent important drivers of intrinsic capacity losses, functional limitations and reduced quality of life in the growing older adult’s population, especially among those presenting with frailty. Despite exercise- and cognitive training-based interventions have shown effectiveness for reducing fall rates, evidence around their putative cumulative effects on falls and fall-related complications (such as fractures, reduced quality of life and functional limitations) in frail individuals remains scarce. The main aim of this study is to explore the effectiveness program combining an individualized exercise program and an executive function-based cognitive training (VIVIFRAIL-COGN) compared to usual care in the prevention of falls and fall-related outcomes over a 1-year follow-up. Methods This study is designed as a four-center randomized clinical trial with a 12-week intervention period and an additional 1-year follow-up. Three hundred twenty frail or pre-frail (≥ 1 criteria of the Frailty Phenotype) older adults (≥ 75 years) with high risk of falling (defined by fall history and gait performance) will be recruited in the Falls Units of the participating centers. They will be randomized in a 1:1 ratio to the intervention group (IG) or the control group (CG). The IG will participate in a home-based intervention combining the individualized Vivifrail multicomponent (aerobic, resistance, gait and balance and flexibility) exercise program and a personalized executive function-based cognitive training (VIVIFRAIL-COGN). The CG group will receive usual care delivered in the Falls Units, including the Otago Exercise Program. Primary outcome will be the incidence of falls (event rate/year) and will be ascertained by self-report during three visits (at baseline, and 6 and 12 weeks) and telephone-based contacts at 6, 9 and 12 months after randomization. Secondarily, effects on measures of physical and cognitive function, quality of life, nutritional, muscle quality and psychological status will be evaluated. Discussion This trial will provide new evidence about the effectiveness of an individualized multidomain intervention by studying the effect of additive effects of cognitive training and physical exercise to prevent falls in older frail persons with high risk of falling. Compared to usual care, the combined intervention is expected to show additive effects in the reduction of the incidence of falls and associated adverse outcomes.The present study is funded by a grant from the Spanish Ministry of Science and Innovation and the Instituto de Salud Carlos III (PI20/01546). Funder Agencies do not play any role in the conducting of the study. Instituto de Salud Carlos III,PI20/01546,Alvaro Casas-Herrer

Práctica avanzada enfermera en los servicios de urgencias hospitalarias

Introducción: La práctica avanzada en enfermería surge de la exigencia de responder a las necesidades de la población en el contexto social actual. Algunos países han incorporado el perfil enfermero de práctica avanzada en los servicios de urgencias, a través de los programas de triaje avanzado. Objetivo: Actualizar los conceptos de enfermera de práctica avanzada y triaje avanzado en los servicios de urgencias hospitalarias. Desarrollo: El triaje avanzado es un ejemplo de práctica enfermera avanzada que se centra en aquellos pacientes clasificados como leves o poco urgentes, con niveles de clasificación IV o V, y permite al profesional enfermero ir un paso más allá en la atención sanitaria urgente de estos pacientes, aplicando unos protocolos o guías de práctica clínica previamente consensuadas por el equipo multidisciplinar, en relación a las enfermedades o problemas de salud más prevalentes de los ciudadanos. El triaje avanzado incluye la solicitud e interpretación de pruebas diagnósticas, la identificación del problema de salud y su abordaje, así como la gestión del control del dolor con analgesia farmacológica. En algunos países donde la práctica avanzada enfermera está más instaurada, se contempla la atención a todo el proceso urgente de la persona con este tipo de problemas de salud, con un impacto positivo en los resultados clínicos, la satisfacción de los pacientes y la optimización de los recursos. Conclusiones: Implementar las competencias de práctica avanzada, como en el triaje avanzado, puede contribuir a reducir la estancia hospitalaria y disminuir la sobresaturación en los servicios de urgencias hospitalarias, así como a la mejora de la eficiencia del sistema sanitario y el aumento de la satisfacción de las personas atendidas

Implementation of advanced triage in the Emergency Department of high complexity public hospital: Research protocol

Aim: To evaluate the efficacy of advanced nurse triage based on the quality of care outcomes of patients attending the Emergency Department of a high-complexity hospital. To analyse the concept of advanced triage and the essential elements of the construct. Design: Mixed longitudinal study, divided into 4 steps; which will include an initial qualitative step, two observational studies and finally, a quasi-experimental study. Clinical trial registration number: NCT05230108. Methods: Step 1 will consist of a concept analysis. Step 2 will include a mapping of advanced practice protocol terminologies. Step 3 will analyse the opinion of health professionals on advanced triage. In step 4: in the retrospective phase (n = 1095), sociodemographic and clinical variables and quality indicators such as waiting time will be analysed. After that, in the prospective phase (n = 547), advanced triage will be implemented and the two cohorts will be compared. The whole study will be carried out from January 2022 to January 2024. Discussion: Patients classified as low complexity at triage are more vulnerable to emergency department overcrowding. The implementation of advanced triage would make it possible to respond to patient needs by offering equitable and quality healthcare, facilitating accessibility, safety and humanization of the emergency department

Effect of a multicomponent exercise program and cognitive stimulation (VIVIFRAIL-COGN) on falls in frail community older persons with high risk of falls: study protocol for a randomized multicenter control trial

Mat complBackground: Falls represent important drivers of intrinsic capacity losses, functional limitations and reduced quality of life in the growing older adult’s population, especially among those presenting with frailty. Despite exercise- and cognitive training-based interventions have shown efectiveness for reducing fall rates, evidence around their puta‑ tive cumulative efects on falls and fall-related complications (such as fractures, reduced quality of life and functional limitations) in frail individuals remains scarce. The main aim of this study is to explore the efectiveness program combining an individualized exercise program and an executive function-based cognitive training (VIVIFRAIL-COGN) compared to usual care in the prevention of falls and fall-related outcomes over a 1-year follow-up. Methods: This study is designed as a four-center randomized clinical trial with a 12-week intervention period and an additional 1-year follow-up. Three hundred twenty frail or pre-frail (≥1 criteria of the Frailty Phenotype) older adults (≥75 years) with high risk of falling (defned by fall history and gait performance) will be recruited in the Falls Units of the participating centers. They will be randomized in a 1:1 ratio to the intervention group (IG) or the control group (CG). The IG will participate in a home-based intervention combining the individualized Vivifrail multicomponent (aerobic, resistance, gait and balance and fexibility) exercise program and a personalized executive function-based cognitive training (VIVIFRAIL-COGN). The CG group will receive usual care delivered in the Falls Units, including the Otago Exercise Program. Primary outcome will be the incidence of falls (event rate/year) and will be ascertained by self-report during three visits (at baseline, and 6 and 12 weeks) and telephone-based contacts at 6, 9 and 12 months after randomization. Secondarily, efects on measures of physical and cognitive function, quality of life, nutritional, muscle quality and psychological status will be evaluated. Discussion: This trial will provide new evidence about the efectiveness of an individualized multidomain interven‑ tion by studying the efect of additive efects of cognitive training and physical exercise to prevent falls in older frail persons with high risk of falling. Compared to usual care, the combined intervention is expected to show additive efects in the reduction of the incidence of falls and associated adverse outcomes. Trial registration: NCT04911179 02/06/2021. © 2022, The Author(s).The present study is funded by a grant from the Spanish Ministry of Science and Innovation and the Instituto de Salud Carlos III (PI20/01546). Instituto de Salud Carlos III, PI20/01546, Alvaro Casas-Herrer

Phenomenology of high-ozone episodes in NE Spain

Ground-level and vertical measurements (performed using tethered and non-tethered balloons), coupled with modelling, of ozone (O3), other gaseous pollutants (NO, NO2, CO, SO2) and aerosols were carried out in the plains (Vic Plain) and valleys of the northern region of the Barcelona metropolitan area (BMA) in July 2015, an area typically recording the highest O3 episodes in Spain. Our results suggest that these very high O3 episodes were originated by three main contributions: (i) the surface fumigation from high O3 reservoir layers located at 1500-3000 m a.g.l. (according to modelling and non-tethered balloon measurements), and originated during the previous day(s) injections of polluted air masses at high altitude; (ii) local/regional photochemical production and transport (at lower heights) from the BMA and the surrounding coastal settlements, into the inland valleys; and (iii) external (to the study area) contributions of both O3 and precursors. These processes gave rise to maximal O3 levels in the inland plains and valleys northwards from the BMA when compared to the higher mountain sites. Thus, a maximum O3 concentration was observed within the lower tropospheric layer, characterised by an upward increase of O3 and black carbon (BC) up to around 100-200 m a.g.l. (reaching up to 300 µg m−3 of O3 as a 10 s average), followed by a decrease of both pollutants at higher altitudes, where BC and O3 concentrations alternate in layers with parallel variations, probably as a consequence of the atmospheric transport from the BMA and the return flows (to the sea) of strata injected at certain heights the previous day(s). At the highest altitudes reached in this study with the tethered balloons (900-1000 m a.g.l.) during the campaign, BC and O3 were often anti-correlated or unrelated, possibly due to a prevailing regional or even hemispheric contribution of O3 at those altitudes. In the central hours of the days a homogeneous O3 distribution was evidenced for the lowest 1 km of the atmosphere, although probably important variations could be expected at higher levels, where the high O3 return strata are injected according to the modelling results and non-tethered balloon data. Relatively low concentrations of ultrafine particles (UFPs) were found during the study, and nucleation episodes were only detected in the boundary layer. Two types of O3 episodes were identified: type A with major exceedances of the O3 information threshold (180 µg m−3 on an hourly basis) caused by a clear daily concatenation of local/regional production with accumulation (at upper levels), fumigation and direct transport from the BMA (closed circulation); and type B with regional O3 production without major recirculation (or fumigation) of the polluted BMA/regional air masses (open circulation), and relatively lower O3 levels, but still exceeding the 8 h averaged health target. To implement potential O3 control and abatement strategies two major key tasks are proposed: (i) meteorological forecasting, from June to August, to predict recirculation episodes so that NOx and VOC abatement measures can be applied before these episodes start; (ii) sensitivity analysis with high-resolution modelling to evaluate the effectiveness of these potential abatement measures of precursors for O3 reduction

Brain function and gait and mobility impairment in older adults

Les síndromes pre-demència, com el deteriorament cognitiu lleu (DCL) i la síndrome de risc cognitiu-motor (SRCM), estan guanyant interès en l'àmbit de la recerca. Els trastorns cognitius i de la marxa s'associen amb conseqüències negatives de salut que podrien prevenir-se en fases precoces. Existeix evidència sobre la relació entre la funció física i cognitiva, recolzada pel substrat neural comú, que inclou el còrtex prefrontal. Les funcions cognitives en el control neural de la marxa prenen especial rellevància durant la marxa en circumstàncies complexes, como el "dual-task". Tècniques de neuroimatge novells estan guanyant rellevància per l'estudi de l'activació cerebral durant el moviment. L'objectiu de la tesis doctoral és l'estudi de les funcions cognitives i motores i la seva interrelació en gent gran amb síndromes pre-demència. La tesis doctoral consisteix en els resultats: Estudi 1 avalua l'execució de "dual-task" i la oxigenació prefrontal en gent gran amb SRCM i Estudi 2 estudia l'execució de "dual-task" i el flux sanguini prefrontal en gent gran amb DCL. Estudi 1 Vem incloure 538 participants i vem comparar l'execució de "dual-task" en SRCM vs. sense SRCM durant "dual-task" (caminar mentres recitaven lletres alternes de l'alfabet). SRCM presentaven pitjor execució cognitiva i de marxa durant la tasca simple així com durant "dual-task" mentres que el cost de "dual-task" ("dual-task cost") no era significativament diferent entre grups. L'execució de "dual-task" mesurada com velocitat de la marxa durant "dual-task" no s'associava amb la funció cognitiva global ni funció executiva. En una submostra (n=325) vem medir la concentració d'hemoglobina oxigenada a nivell prefrontal mitjançant espectroscòpia d'infrarroig proper ("functional near-infrared spectroscopy") mentres realitzaven "dual-task". Els resultats suggereixen una oxigenació prefrontal durant "dual-task" major en participants amb SRCM comparat amb participants sense SRCM. Estudi 2 Vem incloure 49 participants i vem avaluar diferències entre participants amb DCL vs. cognitivament sans. Vem mesurar el flux sanguini (FS) prefrontal mitjançant espectroscòpia de correlació difosa ("functional diffuse correlation spectroscopy") durant un paradigma de "dual-task" que incloïa: marxa normal, marxa amb càlcul sumant +2 ("2-forward count", FWC), marxa amb càlcul restant -3 ("3-backward count", BWC), marxa amb obstacles i elevació de talons en sedestació. Ambdós grups de participants van incrementar el FS durant BWC comparat amb el FS durant marxa normal, junt amb impacte negatiu en velocitat de la marxa. En canvi, únicament participants amb DCL van augmentar FS durant FWC comparat amb marxa normal. "Dual-task" amb FWC va provocar un canvi en el FS (de marxa normal a FWC) major en participants amb DCL comparat amb participants cognitivament sans, en particular a l'hemisferi dret. Conclusions Participants amb SRCM i DCL presentaven velocitat de la marxa durant la marxa normal alentida comparat amb participants sense síndromes pre-demència, els què presentaven un major impacte de "dual-task" sobre la velocitat de la marxa. SRCM i DCL mostraven signes de major activació prefrontal en relació a la doble tasca comparat amb participants sense síndromes pre-demència. Aquest fet podria interpretar-se com ineficàcia dels circuits neurals en els subgrups amb recursos neurals més limitats, és a dir, els participants amb SRCM i DCL. Els resultats recolzen l'ús de tècniques d'espectroscòpia per a neuroimatge en recerca de l'envelliment. En la nostra opinió, els resultats presentats en la tesis doctoral reforcen la necessitat de continuar la recerca en aquest camp per aprofundir l'estudi dels mecanismes neurals de la marxa en l'envelliment i per estudiar el paper que podrien tenir les tècniques d'espectroscòpia en la monitorització de la resposta a intervencions o inclús, potser en el futur, en la pràctica clínica.Los síndromes pre-demencia, como el deterioro cognitivo leve (DCL) y el síndrome de riesgo cognitivo-motor (SRCM), están ganando interés en el ámbito de la investigación. Los trastornos cognitivos y de la marcha se asocian con consecuencias negativas en salud que podrían prevenirse en fases tempranas. Existe evidencia sobre la relación entre la función física y cognitiva, respaldada por un sustrato neural común, incluyendo el córtex prefrontal. Las funciones cognitivas en el control neural de la marcha toman especial relevancia durante la marcha en circunstancias complejas, como el "dual-task". Técnicas de neuroimagen novedosas están ganando relevancia para el estudio de la activación cerebral durante el movimiento. El objetivo de la tesis doctoral es el estudio de las funciones cognitivas y motoras y su interrelación en adultos mayores con síndromes pre-demencia. La tesis doctoral consiste en los resultados de: Estudio 1 evaluó la ejecución de "dual-task" y la oxigenación prefrontal en adultos mayores con SRCM y Estudio 2 estudió la ejecución de "dual-task" y el flujo sanguíneo prefrontal en adultos mayores con DCL. Estudio 1 Se incluyeron 538 adultos mayores y se comparó la ejecución de "dual-task" en SRCM vs. sin SRCM durante "dual-task" (caminar mientras recitaban letras alternas del alfabeto). SRCM presentaban peor ejecución cognitiva y de marcha durante la tarea simple así como durante "dual-task" mientras que el coste de "dual-task" ("dual-task cost") no era significativamente diferente entre grupos. La ejecución de "dual-task" medida como velocidad de la marcha durante "dual-task" no se asoció con desempeño de la función cognitiva global ni función ejecutiva. En una submuestra (n=325) se midió la concentración de hemoglobina oxigenada a nivel prefrontal mediante espectroscopia de infrarrojo cercano ("functional near-infrared spectroscopy") mientras realizaban "dual-task". Los resultados sugieren una oxigenación prefrontal durante "dual-task" mayor en los participantes con SRCM comparado con participantes sin SRCM. Estudio 2 Se incluyeron 49 adultos mayores y se evaluaron diferencias entre participantes con DCL vs. cognitivamente sanos. Se midió el flujo sanguíneo (FS) prefrontal mediante espectroscopia de correlación difusa ("functional diffuse correlation spectroscopy") durante paradigma de "dual-task" que incluía: marcha normal, marcha con cálculo sumando +2 ("2-forward count", FWC), marcha con cálculo restando -3 ("3-backward count", BWC), marcha con obstáculos y elevación de talones en sedestación. Ambos grupos de participantes incrementaron el FS durante BWC comparado con el FS durante marcha normal, junto con impacto negativo en velocidad de la marcha. En cambio, únicamente participantes con DCL mostraron aumento del FS durante FWC comparado con marcha normal. "Dual-task" con FWC causó un cambio en el FS (de marcha normal a FWC) mayor en participantes con DCL comparado con participantes cognitivamente sanos, en particular en hemisferio derecho. Conclusiones Los participantes con SRCM y DCL presentaron velocidad de la marcha durante la marcha normal enlentecida comparado con participantes sin síndromes pre-demencia, los cuales presentaron un mayor impacto de "dual-task" sobre la velocidad de la marcha. SRCM y DCL mostraron signos de mayor activación prefrontal en relación a la doble tarea comparado con los participantes sin síndromes pre-demencia. Esto podría ser interpretado como ineficacia de los circuitos neurales en los subgrupos con recursos neurales más limitados, es decir, los participantes con SRCM y DCL. Los resultados apoyan el uso de técnicas de espectroscopia para neuroimagen en investigación del envejecimiento. En nuestra opinión, los resultados presentados en la tesis doctoral refuerzan la necesidad de continuar la investigación en este campo para profundizar el estudio de los mecanismos neurales de la marcha en el envejecimiento y para estudiar el papel que podrían tener las técnicas de espectroscopia en la monitorización de la respuesta a intervenciones o incluso, quizás en el futuro, en la práctica clínica.Focus of research is shifting to pre-dementia stages, such as mild cognitive impairment (MCI) and motoric cognitive risk syndrome (MCR), to try to prevent negative health outcomes that have been associated to gait and cognitive dysfunction. Vast evidence supports the notion of a motor-cognitive interplay, which is further supported by shared neural substrates that include the prefrontal cortex. Involvement of cognitive control of gait becomes especially relevant during challenging circumstances, such as dual-task. Novel neuroimaging techniques are emerging to study brain activation during actual movement. The global aim of the PhD thesis was to study motor and cognitive function and its interplay in older adults with pre-dementia syndromes. To achieve this goal, the PhD thesis consisted of Study 1 that assessed dual-task performance and prefrontal oxygenation in older adults with MCR and Study 2 that evaluated dual-task performance and prefrontal cerebral blood flow in older adults with MCI. Study 1 We included 538 community-dwelling older adults from the Central Control of Mobility in Aging study and compared participants with and without MCR during a dual-task paradigm (walking while reciting alternate letters of the alphabet). Compared to No MCR, participants with MCR showed worse gait and cognitive performance during single-task and dual-task while the dual-task cost was not signifcantly different. Dual-task gait performance among participants with MCR was not related to global cognition or executive function performance. A subsample of participants (n=325) underwent functional near-infrared spectroscopy measures while performing the walk while talk paradigm. Our findings suggest higher prefrontal oxygenation during dual-task walk in participants with MCR compared to No MCR counterparts. Study 2 We included 49 community-dwelling older adults from the MEDPHOTAGE study and assessed between-group differences between participants with MCI and normocognitive counterparts. We assessed prefrontal blood flow with functional diffuse correlation spectroscopy while participants performed a dual-task paradigm that included: normal walk; walk while 2-forward counting (FWC); walk while 3-backward counting (BWC); walk while negotiating obstacles and heel tapping. Both groups increased significantly their cerebral blood flow during BWC compared to normal walk, along with a negative impact on gait speed. Only among participants with MCI, cerebral blood flow also increased during FWC compared to normal walk, so that FWC is the dual-task in which we observed a statistically significant difference with a higher cerebral blood flow increase from normal walk to FWC in participants with MCI compared to normocognitive participants, in particular in the right hemisphere. Conclusions Participants with MCR and MCI showed slower gait speed during normal walk compared to healthier counterparts, so that the latter showed a higher dual-task interference when looking at absolute values. The findings suggest a higher prefrontal activation related to dual-task in both MCR and MCI compared to healthier controls, which could be interpreted as a neural inefficiency mechanism in the subgroups with poorer neural resources, namely MCR and MCI. Our findings go in line with previous functional near-infrared spectroscopy literature and supports the potential role of spectroscopy techniques to study brain aging. In our opinion, the results presented in the PhD thesis strengthen the need of further research in this field to study the neural mechanisms of brain aging during gait and to assess the potential role of spectroscopy techniques to monitor the response to interventions and, maybe in the future, in clinical practice

Mapping the diagnosis axis of an interface terminology to the NANDA International Taxonomy

Background: Nursing terminologies are designed to support nursing practice but, as with any other clinical tool, they should be evaluated. Cross-mapping is a formal method for examining the validity of the existing controlled vocabularies. Objectives: The study aims to assess the inclusiveness and expressiveness of the nursing diagnosis axis of a newly implemented interface terminology by cross-mapping with the NANDA-I taxonomy. Design/Methods: The study applied a descriptive design, using a cross-sectional, bidirectional mapping strategy. The sample included 728 concepts from both vocabularies. Concept cross-mapping was carried out to identify one-to-one, negative, and hierarchical connections. The analysis was conducted using descriptive statistics. Results: Agreement of the raters" mapping achieved 97%. More than 60% of the nursing diagnosis concepts in the NANDA-I taxonomy were mapped to concepts in the diagnosis axis of the new interface terminology; 71.1% were reversely mapped. Conclusions: Main results for outcome measures suggest that the diagnosis axis of this interface terminology meets the validity criterion of cross-mapping when mapped from and to the NANDA-I taxonomy

Brain function and gait and mobility impairment in older adults|

Les síndromes pre-demència, com el deteriorament cognitiu lleu (DCL) i la síndrome de risc cognitiu-motor (SRCM), estan guanyant interès en l’àmbit de la recerca. Els trastorns cognitius i de la marxa s’associen amb conseqüències negatives de salut que podrien prevenir-se en fases precoces. Existeix evidència sobre la relació entre la funció física i cognitiva, recolzada pel substrat neural comú, que inclou el còrtex prefrontal. Les funcions cognitives en el control neural de la marxa prenen especial rellevància durant la marxa en circumstàncies complexes, como el “dual-task”. Tècniques de neuroimatge novells estan guanyant rellevància per l’estudi de l’activació cerebral durant el moviment. L’objectiu de la tesis doctoral és l’estudi de les funcions cognitives i motores i la seva interrelació en gent gran amb síndromes pre-demència. La tesis doctoral consisteix en els resultats: Estudi 1 avalua l’execució de “dual-task” i la oxigenació prefrontal en gent gran amb SRCM i Estudi 2 estudia l’execució de “dual-task” i el flux sanguini prefrontal en gent gran amb DCL. Estudi 1 Vem incloure 538 participants i vem comparar l’execució de “dual-task” en SRCM vs. sense SRCM durant “dual-task” (caminar mentres recitaven lletres alternes de l’alfabet). SRCM presentaven pitjor execució cognitiva i de marxa durant la tasca simple així com durant “dual-task” mentres que el cost de “dual-task” (“dual-task cost”) no era significativament diferent entre grups. L’execució de “dual-task” mesurada com velocitat de la marxa durant “dual-task” no s’associava amb la funció cognitiva global ni funció executiva. En una submostra (n=325) vem medir la concentració d’hemoglobina oxigenada a nivell prefrontal mitjançant espectroscòpia d’infrarroig proper (“functional near-infrared spectroscopy”) mentres realitzaven “dual-task”. Els resultats suggereixen una oxigenació prefrontal durant “dual-task” major en participants amb SRCM comparat amb participants sense SRCM. Estudi 2 Vem incloure 49 participants i vem avaluar diferències entre participants amb DCL vs. cognitivament sans. Vem mesurar el flux sanguini (FS) prefrontal mitjançant espectroscòpia de correlació difosa (“functional diffuse correlation spectroscopy”) durant un paradigma de “dual-task” que incloïa: marxa normal, marxa amb càlcul sumant +2 (“2-forward count”, FWC), marxa amb càlcul restant -3 (“3-backward count”, BWC), marxa amb obstacles i elevació de talons en sedestació. Ambdós grups de participants van incrementar el FS durant BWC comparat amb el FS durant marxa normal, junt amb impacte negatiu en velocitat de la marxa. En canvi, únicament participants amb DCL van augmentar FS durant FWC comparat amb marxa normal. “Dual-task” amb FWC va provocar un canvi en el FS (de marxa normal a FWC) major en participants amb DCL comparat amb participants cognitivament sans, en particular a l’hemisferi dret. Conclusions Participants amb SRCM i DCL presentaven velocitat de la marxa durant la marxa normal alentida comparat amb participants sense síndromes pre-demència, els què presentaven un major impacte de “dual-task” sobre la velocitat de la marxa. SRCM i DCL mostraven signes de major activació prefrontal en relació a la doble tasca comparat amb participants sense síndromes pre-demència. Aquest fet podria interpretar-se com ineficàcia dels circuits neurals en els subgrups amb recursos neurals més limitats, és a dir, els participants amb SRCM i DCL. Els resultats recolzen l’ús de tècniques d’espectroscòpia per a neuroimatge en recerca de l’envelliment. En la nostra opinió, els resultats presentats en la tesis doctoral reforcen la necessitat de continuar la recerca en aquest camp per aprofundir l’estudi dels mecanismes neurals de la marxa en l’envelliment i per estudiar el paper que podrien tenir les tècniques d’espectroscòpia en la monitorització de la resposta a intervencions o inclús, potser en el futur, en la pràctica clínica.Los síndromes pre-demencia, como el deterioro cognitivo leve (DCL) y el síndrome de riesgo cognitivo-motor (SRCM), están ganando interés en el ámbito de la investigación. Los trastornos cognitivos y de la marcha se asocian con consecuencias negativas en salud que podrían prevenirse en fases tempranas. Existe evidencia sobre la relación entre la función física y cognitiva, respaldada por un sustrato neural común, incluyendo el córtex prefrontal. Las funciones cognitivas en el control neural de la marcha toman especial relevancia durante la marcha en circunstancias complejas, como el “dual-task”. Técnicas de neuroimagen novedosas están ganando relevancia para el estudio de la activación cerebral durante el movimiento. El objetivo de la tesis doctoral es el estudio de las funciones cognitivas y motoras y su interrelación en adultos mayores con síndromes pre-demencia. La tesis doctoral consiste en los resultados de: Estudio 1 evaluó la ejecución de “dual-task” y la oxigenación prefrontal en adultos mayores con SRCM y Estudio 2 estudió la ejecución de “dual-task” y el flujo sanguíneo prefrontal en adultos mayores con DCL. Estudio 1 Se incluyeron 538 adultos mayores y se comparó la ejecución de “dual-task” en SRCM vs. sin SRCM durante “dual-task” (caminar mientras recitaban letras alternas del alfabeto). SRCM presentaban peor ejecución cognitiva y de marcha durante la tarea simple así como durante “dual-task” mientras que el coste de “dual-task” (“dual-task cost”) no era significativamente diferente entre grupos. La ejecución de “dual-task” medida como velocidad de la marcha durante “dual-task” no se asoció con desempeño de la función cognitiva global ni función ejecutiva. En una submuestra (n=325) se midió la concentración de hemoglobina oxigenada a nivel prefrontal mediante espectroscopia de infrarrojo cercano (“functional near-infrared spectroscopy”) mientras realizaban “dual-task”. Los resultados sugieren una oxigenación prefrontal durante “dual-task” mayor en los participantes con SRCM comparado con participantes sin SRCM. Estudio 2 Se incluyeron 49 adultos mayores y se evaluaron diferencias entre participantes con DCL vs. cognitivamente sanos. Se midió el flujo sanguíneo (FS) prefrontal mediante espectroscopia de correlación difusa (“functional diffuse correlation spectroscopy”) durante paradigma de “dual-task” que incluía: marcha normal, marcha con cálculo sumando +2 (“2-forward count”, FWC), marcha con cálculo restando -3 (“3-backward count”, BWC), marcha con obstáculos y elevación de talones en sedestación. Ambos grupos de participantes incrementaron el FS durante BWC comparado con el FS durante marcha normal, junto con impacto negativo en velocidad de la marcha. En cambio, únicamente participantes con DCL mostraron aumento del FS durante FWC comparado con marcha normal. “Dual-task” con FWC causó un cambio en el FS (de marcha normal a FWC) mayor en participantes con DCL comparado con participantes cognitivamente sanos, en particular en hemisferio derecho. Conclusiones Los participantes con SRCM y DCL presentaron velocidad de la marcha durante la marcha normal enlentecida comparado con participantes sin síndromes pre-demencia, los cuales presentaron un mayor impacto de “dual-task” sobre la velocidad de la marcha. SRCM y DCL mostraron signos de mayor activación prefrontal en relación a la doble tarea comparado con los participantes sin síndromes pre-demencia. Esto podría ser interpretado como ineficacia de los circuitos neurales en los subgrupos con recursos neurales más limitados, es decir, los participantes con SRCM y DCL. Los resultados apoyan el uso de técnicas de espectroscopia para neuroimagen en investigación del envejecimiento. En nuestra opinión, los resultados presentados en la tesis doctoral refuerzan la necesidad de continuar la investigación en este campo para profundizar el estudio de los mecanismos neurales de la marcha en el envejecimiento y para estudiar el papel que podrían tener las técnicas de espectroscopia en la monitorización de la respuesta a intervenciones o incluso, quizás en el futuro, en la práctica clínica.Focus of research is shifting to pre-dementia stages, such as mild cognitive impairment (MCI) and motoric cognitive risk syndrome (MCR), to try to prevent negative health outcomes that have been associated to gait and cognitive dysfunction. Vast evidence supports the notion of a motor-cognitive interplay, which is further supported by shared neural substrates that include the prefrontal cortex. Involvement of cognitive control of gait becomes especially relevant during challenging circumstances, such as dual-task. Novel neuroimaging techniques are emerging to study brain activation during actual movement. The global aim of the PhD thesis was to study motor and cognitive function and its interplay in older adults with pre-dementia syndromes. To achieve this goal, the PhD thesis consisted of Study 1 that assessed dual-task performance and prefrontal oxygenation in older adults with MCR and Study 2 that evaluated dual-task performance and prefrontal cerebral blood flow in older adults with MCI. Study 1 We included 538 community-dwelling older adults from the Central Control of Mobility in Aging study and compared participants with and without MCR during a dual-task paradigm (walking while reciting alternate letters of the alphabet). Compared to No MCR, participants with MCR showed worse gait and cognitive performance during single-task and dual-task while the dual-task cost was not signifcantly different. Dual-task gait performance among participants with MCR was not related to global cognition or executive function performance. A subsample of participants (n=325) underwent functional near-infrared spectroscopy measures while performing the walk while talk paradigm. Our findings suggest higher prefrontal oxygenation during dual-task walk in participants with MCR compared to No MCR counterparts. Study 2 We included 49 community-dwelling older adults from the MEDPHOTAGE study and assessed between-group differences between participants with MCI and normocognitive counterparts. We assessed prefrontal blood flow with functional diffuse correlation spectroscopy while participants performed a dual-task paradigm that included: normal walk; walk while 2-forward counting (FWC); walk while 3-backward counting (BWC); walk while negotiating obstacles and heel tapping. Both groups increased significantly their cerebral blood flow during BWC compared to normal walk, along with a negative impact on gait speed. Only among participants with MCI, cerebral blood flow also increased during FWC compared to normal walk, so that FWC is the dual-task in which we observed a statistically significant difference with a higher cerebral blood flow increase from normal walk to FWC in participants with MCI compared to normocognitive participants, in particular in the right hemisphere. Conclusions Participants with MCR and MCI showed slower gait speed during normal walk compared to healthier counterparts, so that the latter showed a higher dual-task interference when looking at absolute values. The findings suggest a higher prefrontal activation related to dual-task in both MCR and MCI compared to healthier controls, which could be interpreted as a neural inefficiency mechanism in the subgroups with poorer neural resources, namely MCR and MCI. Our findings go in line with previous functional near-infrared spectroscopy literature and supports the potential role of spectroscopy techniques to study brain aging. In our opinion, the results presented in the PhD thesis strengthen the need of further research in this field to study the neural mechanisms of brain aging during gait and to assess the potential role of spectroscopy techniques to monitor the response to interventions and, maybe in the future, in clinical practice.Universitat Autònoma de Barcelona. Programa de Doctorat en Medicin