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This study investigates the relationship between motor function and processing speed in preterm children. Processing speed was compared in 145 adolescents, born 25–41 weeks gestational age, utilizing tasks including differing motor demands. The influence of motor cortex excitability and functional motor skills on task performance was assessed. For tasks with motoric demands, differences in performance between preterm and term-born children were mediated by the relationship between gestational age, corticomotor excitability, and motor function. There were no differences in non-motor processing speed task performance between preterm and term-born children. Measures of processing speed may be confounded by a timed motor component. [ABSTRACT FROM AUTHOR]

Non-invasive brain stimulation techniques, such as repetitive transcranial magnetic stimulation (rTMS), can modify cortical excitability in a lasting fashion. The modification can be bi-directional in nature and holds considerable therapeutic promise for a number of neurological conditions. However, the effectiveness of these techniques is currently limited by large intra- and inter-subject variability in the response. A number of factors that contribute to response variability have now been identified, with one of the most important being the history of synaptic activity within the cortical region being targeted by stimulation. In this review we discuss what is currently known about the influence of behaviourally, or experimentally, induced changes in synaptic activity in the cortical (or interconnected) region being targeted by stimulation on the response to rTMS techniques. Understanding such influences is a critical step in the development of effective therapeutic paradigms employing such techniques. [ABSTRACT FROM AUTHOR]

In vivo magnetic resonance imaging has revealed that the anterior half of the corpus callosum is larger in musicians trained intensively from an early age than in untrained subjects. The corpus callosum is crucial for the coordination of bimanual motor activity, but neurophysiological correlates of morphological differences in the corpus callosum of musicians are not known. In the present study we have used transcranial magnetic stimulation (TMS) to assess interhemispheric inhibition in six adult professional musicians who began musical training at an early age. Conditioning TMS was applied to the hand area of the motor cortex of one hemisphere, followed 4–16 ms later by a test stimulus applied to the other hemisphere. Tests were performed at rest, and with the first dorsal interosseous muscle contralateral to the conditioning hemisphere voluntarily active. Conditioning TMS in musicians was 29% less effective at reducing the size of the test MEP at rest, and 63% less effective in the active condition, compared with control subjects. We conclude that transcallosal interhemispheric inhibitory circuits activated by TMS are less effective in musicians than in controls. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine whether prolonged, repetitive mixed nerve stimulation (duty cycle 1 s, 500 ms on–500 ms off, 10 Hz) of the ulnar nerve leads to a change in excitability of primary motor cortex in normal human subjects. Motor-evoked potentials (MEPs) generated in three intrinsic hand muscles [abductor digiti minimi (ADM), first dorsal interosseous (FDI) and abductor pollicis brevis (APB)] by focal transcranial magnetic stimulation were recorded during complete relaxation before and after a period of prolonged repetitive ulnar nerve stimulation at the wrist. Transcranial magnetic stimuli were applied at seven scalp sites separated by 1 cm: the optimal scalp site for eliciting MEPs in the target muscle (FDI), three sites medial to the optimal site and three sites lateral to the optimal stimulation site. The area of the MEPs evoked in the ulnar- (FDI, ADM) but not the median-innervated (APB) muscles was increased after prolonged ulnar nerve stimulation. Centre of gravity measures demonstrated that there was no significant difference in the distribution of cortical excitability after the peripheral stimulation. F-wave responses in the intrinsic hand muscles were not altered after prolonged ulnar nerve stimulation, suggesting that the changes in MEP areas were not the result of stimulus-induced increases in the excitability of spinal motoneurones. Control experiments employing transcranial electric stimulation provided no evidence for a spinal origin for the excitability changes. These results demonstrate that in normal human subjects the excitability of the cortical projection to hand muscles can be altered in a manner determined by the peripheral stimulus applied. [ABSTRACT FROM AUTHOR]

Introduction: Low back pain (LBP) is the leading cause of disability worldwide, with prevalence doubling in the past 14 years. To date, prognostic screening tools display poor discrimination and offer no net benefit of screening over and above a 'treat all' approach. Characteristics of the primary sensory (S1) and motor (M1) cortices may predict the development of chronic LBP, yet the prognostic potential of these variables remains unknown. The Understanding persistent Pain Where it ResiDes (UPWaRD) study aims to determine whether sensorimotor cortex activity, an individual's capacity for plasticity and psychosocial factors in the acute stage of pain, predict LBP outcome at 6 months. This paper describes the methods and analysis plan for the development of the prediction model., Methods and Analysis: The study uses a multicentre prospective longitudinal cohort design with 6-month follow-up. 120 participants, aged 18 years or older, experiencing an acute episode of LBP (less than 6 weeks duration) will be included. Primary outcomes are pain and disability., Ethics and Dissemination: Ethical approval has been obtained from Western Sydney University Human Research Ethics Committee (H10465) and from Neuroscience Research Australia (SSA: 16/002). Dissemination will occur through presentations at national and international conferences and publications in international peer-reviewed journals., Trial Registration Number: ACTRN12619000002189; Pre-results., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Stroke can have devastating consequences for an individual's quality of life. Interventions capable of enhancing response to therapy would be highly valuable to the field of neurological rehabilitation. One approach is to use noninvasive brain stimulation techniques, such as transcranial direct current stimulation, to induce a neuroplastic response. When delivered in combination with rehabilitation exercises, there is some evidence that transcranial direct current stimulation is beneficial. However, responses to stimulation are highly variable. Therefore biomarkers predictive of response to stimulation would be valuable to help select appropriate people for this potentially beneficial treatment., Objective: The objective of this study is to investigate connectivity of the stimulation target, the ipsilesional motor cortex, as a biomarker predictive of response to anodal transcranial direct current stimulation in people with stroke., Methods: This study is a double blind, randomized controlled trial (RCT), with two parallel groups. A total of 68 participants with first ever ischemic stroke with motor impairment will undertake a two week (14 session) treatment for upper limb function (Graded Repetitive Arm Supplementary Program; GRASP). Participants will be randomized 2:1 to active:sham treatment groups. Those in the active treatment group will receive anodal transcranial direct current stimulation to the ipsilesional motor cortex at the start of each GRASP session. Those allocated to the sham treatment group will receive sham transcranial direct current stimulation. Behavioural assessments of upper limb function will be performed at baseline, post treatment, 1 month follow-up and 3 months follow-up. Neurophysiological assessments will include magnetic resonance imaging (MRI), electroencephalography (EEG) and transcranial magnetic stimulation (TMS) and will be performed at baseline, post treatment, 1 month follow-up (EEG and TMS only) and 3 months follow-up (EEG and TMS only)., Results: Participants will be recruited between March 2018 and December 2018, with experimental testing concluding in March 2019., Conclusions: Identifying a biomarker predictive of response to transcranial direct current stimulation would greatly assist clinical utility of this novel treatment approach., Trial Registration: Australia New Zealand Clinical Trials Registry ACTRN12618000443291; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?ACTRN=12618000443291 (Archived by WebCite at http://www.webcitation.org/737QOXXxt)., Registered Report Identifier: RR1-10.2196/10848., (©Ellana Welsby, Michael Ridding, Susan Hillier, Brenton Hordacre. Originally published in JMIR Research Protocols (http://www.researchprotocols.org), 18.10.2018.)

Several techniques and protocols of non-invasive transcranial brain stimulation (NIBS), including transcranial magnetic and electrical stimuli, have been developed in the past decades. Non-invasive transcranial brain stimulation may modulate cortical excitability outlasting the period of non-invasive transcranial brain stimulation itself from several minutes to more than one hour. Quite a few lines of evidence, including pharmacological, physiological and behavioral studies in humans and animals, suggest that the effects of non-invasive transcranial brain stimulation are produced through effects on synaptic plasticity. However, there is still a need for more direct and conclusive evidence. The fragility and variability of the effects are the major challenges that non-invasive transcranial brain stimulation currently faces. A variety of factors, including biological variation, measurement reproducibility and the neuronal state of the stimulated area, which can be affected by factors such as past and present physical activity, may influence the response to non-invasive transcranial brain stimulation. Work is ongoing to test whether the reliability and consistency of non-invasive transcranial brain stimulation can be improved by controlling or monitoring neuronal state and by optimizing the protocol and timing of stimulation., (Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.)

Purpose: Lower limb amputee rehabilitation has traditionally focussed on restoration of gait and balance through use of prosthetic limbs and mobility aids. Despite these efforts, some amputees continue to experience difficulties with mastering prosthetic mobility. Emerging techniques in rehabilitation, such as non-invasive brain stimulation (NIBS), may be an appropriate tool to enhance prosthetic rehabilitation outcomes by promoting "normal" brain reorganisation and function. The purpose of this review is to highlight the potential of NIBS to improve functional outcomes for lower limb amputees., Methods: To demonstrate the rationale for applying NIBS to amputees, this study will first review literature regarding human motor control of gait, followed by neurophysiological reorganisation of the motor system after amputation and the relationship between brain reorganisation and gait function. We will conclude by reviewing literature demonstrating application of NIBS to lower limb muscle representations and evidence supportive of subsequent functional improvements., Results: Imaging, brain stimulation and behavioural evidence indicate that the cortex contributes to locomotion in humans. Following amputation both hemispheres reorganise with evidence suggesting brain reorganisation is related to functional outcomes in amputees. Previous studies indicate that brain stimulation techniques can be used to selectively promote neuroplasticity of lower limb cortical representations with improvements in function., Conclusions: We suggest NIBS has the potential to transform lower limb amputee rehabilitation and should be further investigated. Implications for Rehabilitation Despite extensive rehabilitation some amputees continue to experience difficulty with prosthetic mobility Brain reorganisation following amputation has been related to functional outcomes and may be an appropriate target for novel interventions Non-invasive brain stimulation is a promising tool which has potential to improve functional outcomes for lower limb amputees.

Background/objectives: Over the last ten years, an increasing number of authors have used the theta burst stimulation (TBS) protocol to investigate long-term potentiation (LTP) and long-term depression (LTD)-like plasticity non-invasively in the primary motor cortex (M1) in healthy humans and in patients with various types of movement disorders. We here provide a comprehensive review of the LTP/LTD-like plasticity induced by TBS in the human M1., Methods: A workgroup of researchers expert in this research field review and discuss critically ten years of experimental evidence from TBS studies in humans and in animal models. The review also includes the discussion of studies assessing responses to TBS in patients with movement disorders., Main Findings/discussion: We discuss experimental studies applying TBS over the M1 or in other cortical regions functionally connected to M1 in healthy subjects and in patients with various types of movement disorders. We also review experimental evidence coming from TBS studies in animals. Finally, we clarify the status of TBS as a possible new non-invasive therapy aimed at improving symptoms in various neurological disorders., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Transcranial magnetic stimulation (TMS)-elicited motor-evoked potentials (MEPs) exhibit considerable trial-to-trial variability, potentially reducing the sensitivity and reproducibility of this measure. While increasing the number of trials will improve accuracy, prolonged recording blocks are not always feasible. In this study, we investigated the minimum number of trials required to provide a measure of human corticospinal excitability that is stable both within and between sessions. Single-pulse TMS was applied to the left primary motor cortex, and MEPs were recorded from the right first dorsal interosseous muscle. Approximately 20-30 trials were required to provide a stable measure of MEP amplitude with high within- and between-session reliability. Extending the number of trials beyond 30 provided no additional benefit. Collecting 30 trials may be optimal for reliably estimating corticospinal excitability using TMS. These findings may have significant implications for using TMS to measure corticospinal excitability in both basic and clinical research settings., (Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.)

Objective: Measures of short-interval intracortical inhibition (SICI) can be contaminated by excitatory influences of short-interval intracortical facilitation (SICF), unless examined at individually-optimized interstimulus intervals (ISIs). We hypothesized that age-related differences in SICF would explain previously reported reduced SICI in children and adolescents compared with adults., Methods: Fifty-one participants, aged 8-29years, underwent transcranial magnetic stimulation. SICF curves were constructed to determine the ISI at which SICF was minimal (i.e. the first trough). SICI curves were constructed at this individually-determined ISI with conditioning stimulus (S1) intensities of 60-110% of active motor threshold., Results: There was no effect of age on the ISI corresponding with the SICF trough. However, there was a main effect of age on the amplitude of the conditioned motor-evoked potential at the different ISIs, such that children aged 8-12years demonstrated greater SICF than those aged 16-18 and 19-21years. There was no effect of age on SICI, and no interaction between age group and S1 intensity., Conclusions: Compared with that in older adolescents and young adults, SICF is enhanced in children aged 8-12years. Surprisingly, this enhanced SICF does not appear to reduce the degree of SICI that can be evoked at the first trough in this age group., Significance: This is the first report of enhanced SICF in young children. It remains possible that enhanced SICF may have confounded earlier reports of reduced SICI in children less than 8years., (Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.)