Cortical activity during walking and balance tasks in older adults and in people with Parkinson’s disease: A structured review

Abstract

An emerging body of literature has examined cortical activity during walking and balance tasks in older adults and in people with Parkinson's disease, specifically using functional near infrared spectroscopy (fNIRS) or electroencephalography (EEG). This review provides an overview of this developing area, and examines the disease-specific mechanisms underlying walking or balance deficits. Medline, PubMed, PsychInfo and Scopus databases were searched. Articles that described cortical activity during walking and balance tasks in older adults and in those with PD were screened by the reviewers. Thirty-seven full-text articles were included for review, following an initial yield of 566 studies. This review summarizes study findings, where increased cortical activity appears to be required for older adults and further for participants with PD to perform walking and balance tasks, but specific activation patterns vary with the demands of the particular task. Studies attributed cortical activation to compensatory mechanisms for underlying age- or PD-related deficits in automatic movement control. However, a lack of standardization within the reviewed studies was evident from the wide range of study protocols, instruments, regions of interest, outcomes and interpretation of outcomes that were reported. Unstandardized data collection, processing and reporting limited the clinical relevance and interpretation of study findings. Future work to standardize approaches to the measurement of cortical activity during walking and balance tasks in older adults and people with PD with fNIRS and EEG systems is needed, which will allow direct comparison of results and ensure robust data collection/reporting. Based on the reviewed articles we provide clinical and future research recommendations.

Functional Near-Infrared Spectroscopy to Study Cerebral Hemodynamics in Older Adults During Cognitive and Motor Tasks: A Review

“…However, these findings are still preliminary and it is not yet clear if there is a specific pattern according to age or cognitive status, nor about how these differences should be interpreted. Recently published reviews have assessed the results of studies on fNIRS during cognitive tasks (Herold et al, 2018) or dual tasks (Gramigna et al, 2017;Herold et al, 2017;Leone et al, 2017;Vitorio et al, 2017;Stuart et al, 2018;Kahya et al, 2019) and some of them have chosen to focus on specific clinical profiles (Gramigna et al, 2017;Vitorio et al, 2017) or on methodological aspects such as fNIRS signal processing (Herold et al, 2017(Herold et al, , 2018Vitorio et al, 2017). To the best of our knowledge, our review is the first to focus specifically on older adults regardless of their clinical profile and to assess, from a clinical point of view, studies using only cognitive or motor tasks, as well as DTs.…”

Monitoring multiple cortical regions during walking in young and older adults: Dual-task response and comparison challenges

“…Previous fNIRS studies have been limited to examination of only PFC activity with differences in the activation across other cortical areas under dual-task walking only investigated in young adults (20,21,40), therefore age-related regional differences are unknown (41). Imaging studies have demonstrated that gait is complex and involves multiple cortical regions (24,42).…”

Corticomuscular control of walking in older people and people with Parkinson’s disease

“…The neural mechanisms associated with age-and disease-related gait changes have been investigated using neuroimaging techniques, such as functional magnetic resonance imaging (fMRI), near-infrared spectroscopy (NIRS) and electroencephalography (EEG). Studies using these imaging techniques have shown that gait-related brain activity differs in older adults and people with PD (Maillet et al 2012, Bohnen & Jahn 2013, Herman et al 2013, Hamacher et al 2015, Stuart et al 2018, Wilson et al 2018. For example, older adults exhibit greater activity in various cortical regions including motor, somatosensory, visual and frontal cortices than young individuals during gait imagery as revealed by fMRI (Wai et al 2012, Zwergal et al 2012, Allali et al 2014.…”