Evidence for Acute Electrophysiological and Cognitive Changes Following Routine Soccer Heading.

INTRODUCTION: There is growing concern around the effects of concussion and sub-concussive impacts in sport. Routine game-play in soccer involves intentional and repeated head impacts through ball heading. Although heading is frequently cited as a risk to brain health, little data exist regarding the consequences of this activity. This study aims to assess the immediate outcomes of routine football heading using direct and sensitive measures of brain function. METHODS: Nineteen amateur football players (5 females; age 22±3y) headed machine-projected soccer balls at standardized speeds, modelling routine soccer practice. The primary outcome measure of corticomotor inhibition measured using transcranial magnetic stimulation, was assessed prior to heading and repeated immediately, 24h, 48h and 2weeks post-heading. Secondary outcome measures were cortical excitability, postural control, and cognitive function. RESULTS: Immediately following heading an increase in corticomotor inhibition was detected; further to these electrophysiological alterations, measurable reduction memory function were also found. These acute changes appear transient, with values normalizing 24h post-heading. DISCUSSION: Sub-concussive head impacts routine in soccer heading are associated with immediate, measurable electrophysiological and cognitive impairments. Although these changes in brain function were transient, these effects may signal direct consequences of routine soccer heading on (long-term) brain health which requires further study.

Mental practice with motor imagery in stroke recovery: randomized controlled trial of efficacy.

This randomized controlled trial evaluated the therapeutic benefit of mental practice with motor imagery in stroke patients with persistent upper limb motor weakness. There is evidence to suggest that mental rehearsal of movement can produce effects normally attributed to practising the actual movements. Imagining hand movements could stimulate restitution and redistribution of brain activity, which accompanies recovery of hand function, thus resulting in a reduced motor deficit. Current efficacy evidence for mental practice with motor imagery in stroke is insufficient due to methodological limitations. This randomized controlled sequential cohort study included 121 stroke patients with a residual upper limb weakness within 6 months following stroke (on average <3 months post-stroke). Randomization was performed using an automated statistical minimizing procedure. The primary outcome measure was a blinded rating on the Action Research Arm test. The study analysed the outcome of 39 patients involved in 4 weeks of mental rehearsal of upper limb movements during 45-min supervised sessions three times a week and structured independent sessions twice a week, compared to 31 patients who performed equally intensive non-motor mental rehearsal, and 32 patients receiving normal care without additional training. No differences between the treatment groups were found at baseline or outcome on the Action Research Arm Test (ANCOVA statistical P=0.77, and effect size partial η2=0.005) or any of the secondary outcome measures. Results suggest that mental practice with motor imagery does not enhance motor recovery in patients early post-stroke. In light of the evidence, it remains to be seen whether mental practice with motor imagery is a valid rehabilitation technique in its own right.

The magic grasp: motor expertise in deception.

BACKGROUND: Most of us are poor at faking actions. Kinematic studies have shown that when pretending to pick up imagined objects (pantomimed actions), we move and shape our hands quite differently from when grasping real ones. These differences between real and pantomimed actions have been linked to separate brain pathways specialized for different kinds of visuomotor guidance. Yet professional magicians regularly use pantomimed actions to deceive audiences. METHODOLOGY AND PRINCIPAL FINDINGS: In this study, we tested whether, despite their skill, magicians might still show kinematic differences between grasping actions made toward real versus imagined objects. We found that their pantomimed actions in fact closely resembled real grasps when the object was visible (but displaced) (Experiment 1), but failed to do so when the object was absent (Experiment 2). CONCLUSIONS AND SIGNIFICANCE: We suggest that although the occipito-parietal visuomotor system in the dorsal stream is designed to guide goal-directed actions, prolonged practice may enable it to calibrate actions based on visual inputs displaced from the action.

Recovery of hand function through mental practice: a study protocol.

BACKGROUND: The study aims to assess the therapeutic benefits of motor imagery training in stroke patients with persistent motor weakness. There is evidence to suggest that mental rehearsal of movement can produce effects normally attributed to practising the actual movements. Imagining hand movements could stimulate the redistribution of brain activity, which accompanies recovery of hand function, thus resulting in a reduced motor deficit. METHODS/DESIGN: A multi-centre randomised controlled trial recruiting individuals between one and six months post-stroke (n = 135). Patients are assessed before and after a four-week evaluation period. In this trial, 45 patients daily mentally rehearse movements with their affected arm under close supervision. Their recovery is compared to 45 patients who perform closely supervised non-motor mental rehearsal, and 45 patients who are not engaged in a training program. Motor imagery training effectiveness is evaluated using outcome measures of motor function, psychological processes, and level of disability. DISCUSSION: The idea of enhancing motor recovery through the use of motor imagery rehabilitation techniques is important with potential implications for clinical practice. The techniques evaluated as part of this randomised controlled trial are informed by the current understanding in cognitive neuroscience and the trial is both of scientific and applied interest.