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Background: Following practice of skilled movements, changes continue to take place in the brain that both strengthen and modify memory for motor learning. These changes represent motor memory consolidation a process whereby new memories are transformed from a fragile to a more permanent, robust and stable state. In the present study, the neural correlates of motor memory consolidation were probed using repetitive transcranial magnetic stimulation (rTMS) to the dorsal premotor cortex (PMd). Participants engaged in four days of continuous tracking practice that immediately followed either excitatory 5 HZ, inhibitory 1 HZ or control, sham rTMS. A delayed retention test assessed motor learning of repeated and random sequences of continuous movement; no rTMS was applied at retention.

BackgroundNumerous medications are available for the acute treatment of migraine in adults, and some have now been approved for use in children and adolescents in the ambulatory setting. A systematic review of acute treatment of migraine medication trials in children and adolescents will help clinicians make evidence-informed management choices. ObjectivesTo assess the effects of pharmacological interventions by any route of administration versus placebo for migraine in children and adolescents 17 years of age or less. For the purposes of this review, children were defined as under 12 years of age and adolescents 12 to 17 years of age. Search methodsWe searched seven bibliographic databases and four clinical trial registers as well as gray literature for studies through February 2016. Selection criteriaWe included prospective randomized controlled clinical trials of children and adolescents with migraine, comparing acute symptom relieving migraine medications with placebo in the ambulatory setting. Data collection and analysisTwo reviewers screened titles and abstracts and reviewed the full text of potentially eligible studies. Two independent reviewers extracted data for studies meeting inclusion criteria. We calculated the risk ratios (RRs) and number needed to treat for an additional beneficial outcome (NNTB) for dichotomous data. We calculated the risk difference (RD) and number needed to treat for an additional harmful outcome (NNTH) for proportions of adverse events. The percentage of pain-free patients at two hours was the primary efficacy outcome 1 Drugs for the acute treatment of migraine in children and adolescents (Review)

Consolidation of motor memories associated with skilled practice can occur both online, concurrent with practice, and offline, after practice has ended. The current study investigated the role of dorsal premotor cortex (PMd) in early offline motor memory consolidation of implicit sequence specific learning. Thirty-three participants were assigned to one of three groups of repetitive TMS over left PMd (5 Hz, 1 Hz or control) immediately following practice of a novel continuous tracking task. There was no additional practice following repetitive TMS. This procedure was repeated for 4 days. The continuous tracking task contained a repeated sequence that could be learned implicitly and random sequences that could not. On a separate fifth day, a retention test was performed to assess implicit sequence-specific motor learning of the task. Tracking error was decreased for the group who received 1 Hz repetitive TMS over the PMd during the early consolidation period immediately following practice compared to control or 5 Hz repetitive TMS. Enhanced sequence specific learning with 1 Hz repetitive TMS following practice was due to greater offline consolidation, not differences in online learning between the groups within practice days. A follow-up experiment revealed that stimulation of PMd following practice did not differentially change motor cortical excitability, suggesting that changes in offline consolidation can be largely attributed to stimulation induced changes in PMd. These findings support a differential role for the PMd in support of online and offline sequence specific learning of a visuomotor task and offer converging evidence for competing memory systems.

Background and Purpose-A transient ischemic attack (TIA) is a brief ischemic episode characterized by rapid clinical resolution and not associated with permanent cerebral infarction. Whether changes in intracortical excitability persist and are related to clinical predictors of stroke risk after TIA remains unknown. Methods-Participants were individuals with clinically resolved motor TIA with no structural lesions and healthy age-matched control participants. Single and paired-pulse transcranial magnetic stimulation was used to measure intracortical excitability. Recruitment curves for percent inhibition and facilitation were used to derive excitability thresholds. Correlations between threshold asymmetries and ABCD 2 score were performed. Results-Results showed a significant 3-way interaction with reduced inhibition and enhanced facilitation in the affected compared with unaffected hemisphere after TIA. No significant differences were present in healthy participants. Asymmetries in intracortical inhibition and facilitation were significantly correlated with ABCD 2 score. Conclusions-The present study is the first, to our knowledge, to demonstrate altered intracortical inhibition and facilitation in the affected hemisphere after TIA. These changes occurred on average 2 weeks after clinical signs of TIA resolved and in the absence of structural lesions and were not present in healthy age-matched control participants. Furthermore, this study is the first, to our knowledge, to report that changes in intracortical excitability after TIA are associated with ABCD 2 score. (Stroke. 2011;42:728-733.)

Purpose: The purpose of the present study was to assess changes in thresholds for the onset of short intracortical inhibition (SICI) and intracortical facilitation (ICF) in individuals with chronic stroke compared to age-matched healthy adults and evaluate the relationship between these thresholds and motor function in the chronic stroke group. Methods: Paired-pulse transcranial magnetic stimulation was used to derive thresholds for the onset of SICI and ICF in 12 neurologically healthy and 12 individuals with chronic stroke. Motor evoked potentials were elicited by a test stimulus of fixed intensity preceded by a conditioning stimulus ranging from 0%-125% of active motor threshold to generate recruitment curves. Regression functions were fit to these recruitment curves to identify thresholds for the onset of SICI and ICF. Mixed measures analysis of variance was used to compare thresholds for each hemisphere within and between groups. Results: Results showed a significant three-way interaction between Group (stroke, healthy), Hemisphere (ipsilesional, contralesional) and Stimulus interval (2 ms, 12 ms). Significant differences in the thresholds for the onset of both SICI and ICF were present in individuals with chronic stroke, with no between hemisphere differences for the control group. When compared to age-matched controls, comparisons revealed significant reductions in ipsilesional, but not contralesional thresholds for the onset of ICF, and significant reductions in contralesional, but not ipsilesional, thresholds for the onset of SICI in individuals with chronic stroke. In addition, as thresholds for ICF and SICI in stroke patients approached the level of healthy adults, higher function on the Wolf Motor Function Test was observed. Conclusions: Reduced thresholds for the onset of SICI and ICF observed in the present study indicate that both inhibitory and facilitatory systems mediate changes in cortical excitability in chronic stroke patients. The association between higher onset thresholds and motor function in the stroke group also suggests that these thresholds have potential utility for tracking functional 694 J.D. Edwards et al. / Intracortical thresholds in chronic strokemotor improvements in patients with chronic stroke. This study provides new insights to further characterize changes in intracortical neurotransmission that play an important role in modulating neuroplasticity and the potential relationship between inhibitory and facilitatory networks and motor function post-stroke.

Locomotor adaptations to a novel environment can be measured through changes in muscle activity patterns and lower limb kinematics. The location and mechanisms underlying these adaptive changes are unknown. The purposes of the current study were (1) to determine whether corticospinal tract (CST) excitability is altered by resisted walking and (2) to ascertain whether changes in cortical excitability are muscle specific. Forty healthy participants walked with a robotic gait device (Lokomat) that applied a velocity-dependent resistance against hip and knee movements during walking. CST excitability was assessed by quantifying motor evoked potentials (MEPs) elicited by transcranial magnetic stimulation immediately before and after baseline and resisted walking. MEPs were measured in either the biceps femoris (BF) or the rectus femoris (RF). Recruitment curves were collected by stimulating in 5 % increments from 105 to 145 % of active motor threshold. Results demonstrated a significant increase in MEP amplitude in the BF following baseline walking in the Lokomat. The RF did not demonstrate these changes. There was no further change in MEP size following resisted walking in either muscle group. These results suggest that locomotion increases CST excitability in a muscle-specific fashion. As such, it may be important for determining how to enhance the central nervous system's ability to integrate adaptive strategies during walking.