Correlation Between Gait and Near-Infrared Brain Functional Connectivity Under Cognitive Tasks in Elderly Subjects With Mild Cognitive Impairment

Older adults with mild cognitive impairment (MCI) have a high risk of developing Alzheimer’s disease. Gait performance is a potential clinical marker for the progression of MCI into dementia. However, the relationship between gait and brain functional connectivity (FC) in older adults with MCI remains unclear. Forty-five subjects [MCI group, n = 23; healthy control (HC) group, n = 22] were recruited. Each subject performed a walking task (Task 01), counting backward–walking task (Task 02), naming animals–walking task (Task 03), and calculating–walking task (Task 04). The gait parameters and cerebral oxygenation signals from the left prefrontal cortex (LPFC), right prefrontal cortex (RPFC), left motor cortex (LMC), right motor cortex (RMC), left occipital leaf cortex (LOL), and right occipital leaf cortex (ROL) were obtained simultaneously. Wavelet phase coherence was calculated in two frequency intervals: low frequency (interval I, 0.052–0.145 Hz) and very low frequency (interval II, 0.021–0.052 Hz). Results showed that the FC of RPFC–RMC is significantly lower in interval I in Task 03 compared with that in Task 02 in the MCI group (p = 0.001). Also, the right relative symmetry index (IDpsR) is significantly lower in Task 03 compared with that in Task 02 (p = 0.000). The IDpsR is positively correlated with the FC of RPFC–RMC in interval I in the MCI group (R = 0.205, p = 0.041). The gait symmetry such as left relative symmetry index (IDpsL) and IDpsR is significantly lower in the dual-task (DT) situation compared with the single task in the two groups (p < 0.05). The results suggested that the IDpsR might reflect abnormal change in FC of RPFC–RMC in interval I in the MCI population during Task 03. The gait symmetry is affected by DTs in both groups. The findings of this study may have a pivotal role in the early monitoring and intervention of brain dysfunction among older adults with MCI.

Dual and triple tasks performance in institutionalized prefrail and frail older adults

OBJECTIVE

The aim of this pilot study was to investigate differences on dual- and triple-task performance in institutionalized prefrail and frail older adults. Performance on these tasks is relevant since many activities of daily living involve simultaneous motor and cognitive tasks.

METHODS

We used a phenotypic description of frailty based on the presence or absence of five criteria related to physical fitness and metabolism (unintentional weight loss, self-reported exhaustion, muscle weakness, low gait speed, and low physical activity). Thirty-three institutionalized older adults (≥ 65 years, 78.8% females) were divided according to their frailty status. Participants completed cognitive tasks (a phonemic verbal fluency task and a visuospatial tracking task) while cycling on a stationary cycle (upper- and lower-extremity function was assessed). Cycling (number of arm and foot cycles) and cognitive (number of correct answers) performances were measured during single-, dual-, and triple-task conditions. Performances and costs of dual -and triple- tasking on cycling and cognitive performances were compared between prefrail and frail groups.

RESULTS

Prefrail and frail older adults did not differ in their performance in dual-tasks; however, frail older adults showed a poorer performance in the triple-task.

CONCLUSIONS

Although future studies need to confirm our observations in larger samples, this pilot study suggests that developing new tools based on triple tasking could be useful for the comprehensive assessment of frailty.

[Dual-tasks is an indicator of cognitive deficit specificity in patients after traumatic brain injury]

AIM

To investigate the brain activity impairment in patients after traumatic brain injury (TBI) during dual-tasks in comparison with the normal ranges.

MATERIAL AND METHODS

Electroencephalographic (EEG), stabilographic and clinical study was performed in 9 patients (mean age 25±1.2 years) for up to 3 months after a mild traumatic brain injury (TBI) in comparison with 18 healthy subjects (mean age 26.6±0.07 years). All participants of the study performed two motor tasks and two cognitive tasks that were carried out in isolation, and simultaneously (dual-tasks).

RESULTS

Clinical examination revealed cognitive deficit in TBI patients with safety of postural control. The EEG data demonstrated a pronounced decrease in the coherence for slow rhythms in the left hemisphere and frontal areas during cognitive tasks performance. In healthy subjects, an increase in EEG coherence for slow spectral bands was observed in these brain areas.

CONCLUSION

Dual-tasks are an informative method for estimation of predominant cognitive deficit after mild TBI and the use of this approach for rehabilitation contributes to positive clinical dynamics.

Enactive Approach and Dual-Tasks for the Treatment of Severe Behavioral and Cognitive Impairment in a Person with Acquired Brain Injury: A Case Study

One of the most important sequela in persons who suffer from acquired brain injury is a behavioral disorder. To date, the primary approaches for the rehabilitation of this sequela are Applied Behavior Analysis, Cognitive-Behavior Therapy, and Comprehensive-Holistic Rehabilitation Programs. Despite this theoretical plurality, none of these approaches focuses on rehabilitating behavioral disorders considering the relation between affordance and environmental adaptation. To introduce this therapeutic view to neurorehabilitation, we apply the theoretical tenets of the enactive paradigm to the rehabilitation of a woman with severe behavioral and cognitive impairment. Over seventeen sessions, her behavioral and cognitive performance was assessed in relation to two seated affordances (seated on a chair and seated on a ball 65 cm in diameter) and the environmental adaptation while she was working on various cognitive tasks. These two seated affordances allowed to incorporate the theoretical assumptions of the enactive approach and to know how the behavior and the cognition were modified based on these two postural settings and the environmental adaptation. The findings indicate that the subject exhibited better behavioral (physical and verbal) and cognitive (matching success and complex task) performances when the woman worked on the therapeutic ball than when the woman was on the chair. The enactive paradigm applied in neurorehabilitation introduces a level of treatment that precedes behavior and cognition. This theoretical consideration allowed the discovery of a better relation between a seated affordance and the environmental adaptation for the improvement behavioral and cognitive performance in our case study.

The planning and control model (PCM) of motorvisual priming: reconciling motorvisual impairment and facilitation effects

Previous research on dual-tasks has shown that, under some circumstances, actions impair the perception of action-consistent stimuli, whereas, under other conditions, actions facilitate the perception of action-consistent stimuli. We propose a new model to reconcile these contrasting findings. The planning and control model (PCM) of motorvisual priming proposes that action planning binds categorical representations of action features so that their availability for perceptual processing is inhibited. Thus, the perception of categorically action-consistent stimuli is impaired during action planning. Movement control processes, on the other hand, integrate multi-sensory spatial information about the movement and, therefore, facilitate perceptual processing of spatially movement-consistent stimuli. We show that the PCM is consistent with a wider range of empirical data than previous models on motorvisual priming. Furthermore, the model yields previously untested empirical predictions. We also discuss how the PCM relates to motorvisual research paradigms other than dual-tasks.