Executive functions and working memory in motor control: Does the type of MCI matter?

EEG Reveals Alterations in Motor Imagery in People With Amnestic Mild Cognitive Impairment

OBJECTIVES

Motor imagery has been used to investigate the cognitive mechanism of motor control. Although behavioral and electrophysiological changes in motor imagery in people with amnestic mild cognitive impairment (aMCI) have been reported, deficits in different types of imagery remain unclear. To explore this question, we used electroencephalography (EEG) to study neural correlates of visual imagery (VI) and kinesthetic imagery (KI) and their relationship to cognitive function in people with aMCI.

METHODS

A hand laterality judgment task was used to induce implicit motor imagery in 29 people with aMCI and 40 healthy controls during EEG recording. Mass univariate and multivariate EEG analysis was applied to explore group differences in a data-driven manner.

RESULTS

Modulation of stimuli orientation to event-related potential (ERP) amplitudes differed significantly between groups at 2 clusters located in the posterior-parietal and frontal areas. Multivariate decoding revealed sufficient representation of VI-related orientation features in both groups. Relative to healthy controls, the aMCI group lacked accurate representation of KI-related biomechanical features, suggesting deficits in automatic activation of KI strategy. Electrophysiological correlates were associated with episodic memory, visuospatial function, and executive function. Higher decoding accuracy of biomechanical features predicted better executive function via longer response time in the imagery task in the aMCI group.

DISCUSSION

These findings reveal electrophysiological correlates related to motor imagery deficits in aMCI, including local ERP amplitudes and large-scale activity patterns. Alterations in EEG activity are related to cognitive function in multiple domains, including episodic memory, suggesting the potential of these EEG indices as biomarkers of cognitive impairment.

Does dual task merged in a mixed physical exercise protocol impact the mobility under dual task conditions in mild impaired stroke survivors? A feasibility, safety, randomized, and controlled pilot trial

PURPOSE

To investigate the feasibility, safety, and effects of dual task (DT) in a mixed physical exercise protocol on mobility under DT in stroke survivors.

MATERIALS AND METHODS

Twenty-six chronic mild-impaired stroke survivors (age 51.57 ± 12.55; men= 13, women= 13) were randomly assigned into Experimental Group participating in a 15-week mixed (aerobic and resistance exercises performing a cognitive DT condition simultaneously) physical exercise protocol (30 sessions, 2x/week, duration of 60-90 min), and Control Group engaged in the same protocol without DT. Feasibility and outcome measures were assessed before and after the intervention and in a 5-week follow-up.

RESULTS

DT physical exercise protocol was viable and safe. This protocol also improved mobility and gait when performed under DT, which was not found in the control group. DT does not influence aerobic resistance, strength, and balance responsiveness. It does not present any improvement in cognition, self-efficacy for falls, and quality of life.

CONCLUSION

The results indicate that mixed physical exercise under DT is feasible and safe for mild-impaired stroke survivors. Stroke survivors demonstrate more significant improvement in the mobility performance under DT when submitted to a DT mixed physical exercise protocol than the standard physical exercise intervention.

TRIAL REGISTRATION

Brazilian clinical trials registry (RBR-4mvzz6); WHO trial record (U1111-1198-7173)IMPLICATIONS FOR REHABILITATIONDT training can be prescribed by using clear and precise parameters for stroke survivors.Physical Exercise without DT requirements did not improve mobility performing and cognitive tasks simultaneously in stroke survivors.Clinicians are encouraged to incorporate DT requirements into the exercise routines to enhance mobility under DT to mild-moderate stroke survivors.