Aging effects on electrical and hemodynamic responses in the sensorimotor network during unilateral proximal upper limb functional tasks

Healthy aging leads to poorer performance in upper limb (UL) daily living movements. Understanding the neural correlates linked with UL functional movements may help to better understand how healthy aging affects motor control. Two non-invasive neuroimaging methods allow for monitoring the movement-related brain activity: functional near-infrared spectroscopy (fNIRS) and electroencephalography (EEG), respectively based on the hemodynamic response and electrical activity of brain regions. Coupled, they provide a better spatiotemporal mapping. The aim of this study was to evaluate the effect of healthy aging on the bilateral sensorimotor (SM1) activation patterns of functional proximal UL movements. Twenty-one young and 21 old healthy participants realized two unilateral proximal UL movements during: i) a paced reaching target task and ii) a circular steering task to capture the speed-accuracy trade-off. Combined fNIRS-EEG system was synchronised with movement capture system to record SM1 activation while moving. The circular steering task performance was significantly lower for the older group. The rate of increase in hemodynamic response was longer in the older group with no difference on the amplitude of fNIRS signal for the two tasks. The EEG results showed aging related reduction of the alpha-beta rhythms synchronisation but no desynchronisation modification. In conclusion, this study uncovers the age-related changes in brain electrical and hemodynamic response patterns in the bilateral sensorimotor network during two functional proximal UL movements using two complementary neuroimaging methods. This opens up the possibility to utilise combined fNIRS-EEG for monitoring the movement-related neuroplasticity in clinical practice.

Does cognitive loading interfere with walking control?

BACKGROUND

Cognitive-motor interference is a common method used to investigate the cognitive demands of human walking. Using this methodology, consistent effects emerge: under cognitive load, walking velocity decreases, while spatio-temporal variability of walking increases. These effects are often interpreted as indicative of an interference in the ability to control gait. However, walking velocity is highly correlated with most gait parameters; thus, the increase in variability does not necessarily reflect reduced control, but rather a constant signal-to-noise ratio.

METHODS

To investigate the effect of cognitive loading on gait variability, we retrospectively analysed 3721 records of healthy young adults, walking with and without a concurrent cognitive task, on a treadmill.

RESULTS

Stride duration and length increased under cognitive load, while the variability of these parameters decreased. Further, these effects were different between participants starting to walk without cognitive loading and those starting to walk with cognitive loading.

CONCLUSIONS

Dual tasking is more likely to divert the focus of attention away from the walking task, causing a shift of balance between automatic and conscious control, as opposed to interference per-se.

Therapeutic benefits of music-based synchronous finger tapping in Parkinson's disease-an fNIRS study protocol for randomized controlled trial in Dalian, China

BACKGROUND

Music therapy improves neuronal activity and connectivity of healthy persons and patients with clinical symptoms of neurological diseases like Parkinson's disease, Alzheimer's disease, and major depression. Despite the plethora of publications that have reported the positive effects of music interventions, little is known about how music improves neuronal activity and connectivity in afflicted patients.

METHODS

For patients suffering from Parkinson's disease (PD), we propose a daily 25-min music-based synchronous finger tapping (SFT) intervention for 8 weeks. Eligible participants with PD are split into two groups: an intervention group and a control arm. In addition, a third cohort of healthy controls will be recruited. Assessment of finger tapping performances, the Unified Parkinson's Disease Rating Scale (UPDRS), an n-back test, the Montreal Cognitive Assessment (MoCA), as well as oxygenated hemoglobin (HbO2), deoxygenated hemoglobin (HbR), and total hemoglobin activation collected by functional near-infrared spectroscopy (fNIRS) are measured at baseline, week 4 (during), week 8 (post), and week 12 (retention) of the study. Data collected from the two PD groups are compared to baseline performances from healthy controls.

DISCUSSION

This exploratory prospective trial study investigates the cortical neuronal activity and therapeutic effects associated with an auditory external cue used to induce automatic and implicit synchronous finger tapping in patients diagnosed with PD. The extent to which the intervention is effective may be dependent on the severity of the disease. The study's findings are used to inform larger clinical studies for optimization and further exploration of the therapeutic effects of movement-based music therapy on neural activity in neurological diseases.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04212897 . Registered on December 30, 2019. The participant recruitment and study protocol have received ethical approval from the First Affiliated Hospital of Dalian Medical University. The hospital Protocol Record number is PJ-KY-2019-123. The protocol was named "fNIRS Studies of Music Intervention of Parkinson's Disease." The current protocol is version 1.1, revised on September 1, 2020.

Risk factors for musculoskeletal injury in elite pre-professional modern dancers: A prospective cohort prognostic study

OBJECTIVES

To examine risk factors for injury in pre-professional modern dancers.

DESIGN

With prospectively designed screening and injury surveillance, we evaluated four risk factors as categorical predictors of injury: i) hypermobility; ii) dance technique motor-control; iii) muscle tightness; iv) previous injury. Screening and injury data of 180 students enrolled in a university modern dance program were reviewed over 4-yrs of training. Dancers were divided into 3-groups based on predictor scores. Dance exposure was based on hours of technique classes/wk. Negative binomial log-linear analyses were conducted with the four predictors, p < 0.05.

RESULTS

Dancers with low and high Beighton scores were 1.43 and 1.22 times more likely to sustain injury than dancers with mid-range scores (p ≤ 0.03). Dancers with better technique (low or medium scores) were 0.86 and 0.63 times less likely to sustain injury (p = 0.013 and p < 0.001) compared to those with poor technique. Dancers with one or 2-4 tight muscles were 2.7 and 4.0 times more likely to sustain injury (p ≤ 0.046). Dancers who sustained 2-4 injuries in the previous year were 1.38 times more likely to sustain subsequent injury (p < 0.001).

CONCLUSIONS

This contributes new information on the value of preseason screening. Dancers with these risk factors may benefit from prevention programs.