Inter-cortical modulation from premotor to motor plasticity.

Key Points: Synaptic plasticity is involved in daily activities but abnormal plasticity may be deleterious. In this study, we found that motor plasticity could be modulated by suppressing the premotor cortex with the theta burst form of repetitive transcranial magnetic stimulation. Such changes in motor plasticity were associated with reduced learning of a simple motor task.

Observing Without Acting: A Balance of Excitation and Suppression in the Human Corticospinal Pathway?

Transcranial magnetic stimulation (TMS) studies of human primary motor cortex (M1) indicate an increase corticospinal excitability during the observation of another's action. This appears to be somewhat at odds with recordings of pyramidal tract neurons in primate M1 showing that there is a balance of increased and decreased activity across the population. TMS is known to recruit a mixed population of cortical neurons, and so one explanation for previous results is that TMS tends to recruit those excitatory output neurons whose activity is increased during action observation.

Dietary polyphenol intake and their major food sources in the Mexican Teachers' Cohort.

Several descriptive studies on the intake of polyphenols, mostly flavonoids, have been published, especially in Europe and the USA, but insufficient data are still available in Latin-American countries, where different types of foods are consumed and different dietary habits are observed. The goal of this cross-sectional study was to estimate dietary intakes of polyphenols, including grand total, total per classes and subclasses and individual compounds, and to identify their main food sources in Mexican women. The Mexican Teachers' Cohort includes 115 315 female teachers, 25 years and older, from twelve states of Mexico, including urban and rural areas.

Reappraising the role of motor surround inhibition in dystonia.

Background: Surround inhibition (SI) in the motor system has been described to be decreased in patients with focal hand dystonia (FHD) but no evidence currently exists for patients with cervical dystonia (CD).

Objective: To characterise the SI profiles in three groups of participants: healthy volunteers, patients with FHD and patients with CD. To provide sample size calculations for future studies.

Dietary intake of total polyphenol and polyphenol classes and the risk of colorectal cancer in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort.

Polyphenols may play a chemopreventive role in colorectal cancer (CRC); however, epidemiological evidence supporting a role for intake of individual polyphenol classes, other than flavonoids is insufficient. We evaluated the association between dietary intakes of total and individual classes and subclasses of polyphenols and CRC risk and its main subsites, colon and rectum, within the European Prospective Investigation into Cancer and Nutrition (EPIC) study. The cohort included 476,160 men and women from 10 European countries.

Evidence for a subcortical contribution to intracortical facilitation.

Intracortical facilitation (ICF) describes the facilitation of an EMG response (motor evoked potential) to a suprathreshold pulse (S2) of transcranial magnetic stimulation (TMS) by a preceding subthreshold pulse (S1) given 10-15 ms earlier. ICF is widely assumed to originate from intracortical mechanisms. In this study, we used spinal H-reflexes to test whether subcortical mechanisms can also contribute to the facilitation.

Cortical Paired Associative Stimulation Influences Response Inhibition: Cortico-cortical and Cortico-subcortical Networks.

Background: The ability to stop a suboptimal response is integral to decision making and is commonly impaired across psychiatric disorders. Cortical paired associative stimulation (cPAS) is a form of transcranial magnetic stimulation in which paired pulses can induce plasticity at cortical synapses. Here we used cPAS protocols to target cortico-cortical and cortico-subcortical networks by using different intervals between the paired pulses in an attempt to modify response inhibition.

Effects of pulse width, waveform and current direction in the cortex: A combined cTMS-EEG study.

Background: the influence of pulse width, pulse waveform and current direction on transcranial magnetic stimulation (TMS) outcomes is of critical importance. However, their effects have only been investigated indirectly with motor-evoked potentials (MEP). By combining TMS and EEG it is possible to examine how these factors affect evoked activity from the cortex and compare that with the effects on MEP.

The Role of Task Difficulty in Learning a Visuomotor Skill.

Introduction: Task difficulty affects the amount of interpretable information from a task, which is thought to interfere with motor learning. However, it is unclear whether task difficulty in itself is a stimulus for motor learning because the experimental evidence is mixed in support of the optimal challenge point framework that predicts one specific level of task difficulty to produce the greatest magnitude of motor learning.

Purpose: We determined the effects of functional task difficulty on motor skill acquisition, retention, and transfer.

Measurement of motor-evoked potential resting threshold and amplitude of proximal and distal arm muscles in healthy adults. A reliability study.

Purpose: Reliability of motor-evoked potential threshold and amplitude measurement of upper limb muscles is important when detecting changes in cortical excitability. The objective of this study was to investigate intra-rater, test-retest reliability and minimal detectable change of resting motor threshold and amplitude of a proximal and distal upper limb muscles, anterior deltoid and distal extensor digitorum communis in healthy adults.

Method: To measure motor-evoked potential responses, transcranial magnetic stimulation was interfaced with electromyography and neuronavigation equipment.

Breast screening in symptomatic women over 35 years of age: improvements in service efficiency.

Introduction: The rationalization of cancer services in Ireland saw all women with symptomatic breast problems referred to one of the eight regional cancer centers. A pilot triaging system was introduced in St Vincent's University Hospital to streamline these services. Women over 35 years who do not meet urgent referral criteria are referred for a mammogram prior to a clinic appointment ("image first").

Short-interval intracortical inhibition: Comparison between conventional and threshold-tracking techniques.

Background: Short-interval intracortical inhibition (SICI) is conventionally measured as the relative amplitude reduction of motor evoked potentials (MEPs) by subthreshold conditioning stimuli. In threshold-tracking SICI (T-SICI), stimulus intensity is instead adjusted repeatedly to maintain a constant MEP and inhibition is measured as the relative threshold increase. T-SICI is emerging as a useful diagnostic test, but its relationship to conventional amplitude SICI (A-SICI) is unclear.

Effect of donepezil on transcranial magnetic stimulation parameters in Alzheimer's disease.

Introduction: There is a need for a reliable, noninvasive biomarker for Alzheimer's disease (AD). We assessed whether short-latency afferent inhibition (SAI), a transcranial magnetic stimulation paradigm that assesses cholinergic circuits of the brain, could become such a biomarker.

Methods: Nineteen patients with AD underwent four SAI testing sessions.

Prostate-specific antigen velocity in a prospective prostate cancer screening study of men with genetic predisposition.

This corrects the article DOI: 10.1038/bjc.2017.

Voluntary inhibitory motor control over involuntary tic movements.

Inhibitory control is crucial for normal adaptive motor behavior. In hyperkinesias, such as tics, disinhibition within the cortico-striato-thalamo-cortical loops is thought to underlie the presence of involuntary movements. Paradoxically, tics are also subject to voluntary inhibitory control.

High motor variability in DYT1 dystonia is associated with impaired visuomotor adaptation.

For the healthy motor control system, an essential regulatory role is maintaining the equilibrium between keeping unwanted motor variability in check whilst allowing informative elements of motor variability. Kinematic studies in children with generalised dystonia (due to mixed aetiologies) show that movements are characterised by increased motor variability. In this study, the mechanisms by which high motor variability may influence movement generation in dystonia were investigated.

Functional Strength Training and Movement Performance Therapy for Upper Limb Recovery Early Poststroke-Efficacy, Neural Correlates, Predictive Markers, and Cost-Effectiveness: FAST-INdiCATE Trial.

Background: Variation in physiological deficits underlying upper limb paresis after stroke could influence how people recover and to which physical therapy they best respond.

Objectives: To determine whether functional strength training (FST) improves upper limb recovery more than movement performance therapy (MPT). To identify: (a) neural correlates of response and (b) whether pre-intervention neural characteristics predict response.

Effectiveness of systemic family therapy versus treatment as usual for young people after self-harm: a pragmatic, phase 3, multicentre, randomised controlled trial.

Background: Self-harm in adolescents is common and repetition occurs in a high proportion of these cases. Scarce evidence exists for effectiveness of interventions to reduce self-harm.

Methods: This pragmatic, multicentre, randomised, controlled trial of family therapy versus treatment as usual was done at 40 UK Child and Adolescent Mental Health Services (CAMHS) centres.

Neurophysiological adaptations in the untrained side in conjunction with cross-education of muscle strength: a systematic review and meta-analysis.

We reviewed the evidence from randomized controlled trials (RCTs) focusing on the neurophysiological adaptations in the untrained side associated with cross-education of strength (CE) and pooled data into definite effect estimates for neurophysiological variables assessed in chronic CE studies. Furthermore, scoping directions for future research were provided to enhance the homogeneity and comparability of studies investigating the neural responses to CE. The magnitude of CE was 21.

Direct detection of glucuronide metabolites of lidocaine in sheep urine.

The anaesthetic lidocaine is metabolised quickly to produce a series of metabolites, including several hydroxylated metabolites, which are further metabolised by addition of a glucuronic acid moiety. Analysis of these glucuronide metabolites in urine is performed indirectly by cleaving the glucuronic acid group using β-glucuronidase. However, direct analysis of intact glucuronide conjugates is a more straightforward approach as it negates the need for long hydrolysis incubations, and minimises the oxidation of sensitive hydrolysis products, while also distinguishing between the two forms of hydroxylated metabolites.

Saliency Detection as a Reactive Process: Unexpected Sensory Events Evoke Corticomuscular Coupling.

Survival in a fast-changing environment requires animals not only to detect unexpected sensory events, but also to react. In humans, these salient sensory events generate large electrocortical responses, which have been traditionally interpreted within the sensory domain. Here we describe a basic physiological mechanism coupling saliency-related cortical responses with motor output.

Motor cortex synchronization influences the rhythm of motor performance in premanifest huntington's disease.

Background: In Huntington's disease there is evidence of structural damage in the motor system, but it is still unclear how to link this to the behavioral disorder of movement. One feature of choreic movement is variable timing and coordination between sequences of actions. We postulate this results from desynchronization of neural activity in cortical motor areas.

TMS of primary motor cortex with a biphasic pulse activates two independent sets of excitable neurones.

Background: Biphasic pulses produced by most commercially available TMS machines have a cosine waveform, which makes it difficult to study the interaction between the two phases of stimulation.

Objective: We used a controllable pulse TMS (cTMS) device delivering quasi-rectangular pulse outputs to investigate whether monophasic are more effective than biphasic pulses.

Methods: Temporally symmetric ("biphasic") or highly asymmetric ("monophasic") charge-balanced biphasic stimuli were used to target the hand area of motor cortex in the anterior-posterior (AP) or posterior-anterior (PA) initial current direction.