Lucy S. Chipchase

The number of stimuli required to reliably assess corticomotor excitability and primary motor cortical representations using transcranial magnetic stimulation (TMS): a systematic review and meta-analysis

BackgroundTranscranial magnetic stimulation (TMS) is a non-invasive means by which to assess the structure and function of the central nervous system. Current practices involve the administration of multiple stimuli over target areas of a participant’s scalp. Decreasing the number of stimuli delivered during TMS assessments would improve time efficiency and decrease participant demand. However, doing so may also compromise the within- or between-session reliability of the technique. The aim of this review was therefore to determine the minimum number of TMS stimuli required to reliably measure (i) corticomotor excitability of a target muscle at a single cranial site and (ii) topography of the primary motor cortical representation of a target muscle across multiple cranial sites.MethodsDatabase searches were performed to identify diagnostic reliability studies published before May 2015. Two independent reviewers extracted data from studies employing single-pulse TMS to measure (i) the corticomotor excitability at a single cranial site or (ii) the topographic cortical organisation of a target muscle across a number of cranial sites. Outcome measures included motor evoked potential amplitude, map volume, number of active map sites and location of the map centre of gravity.ResultsOnly studies comparing the reliability of varying numbers of stimuli delivered to a single cranial site were identified. Five was the lowest number of stimuli that could be delivered to produce excellent within-session motor evoked potential (MEP) amplitude reliability (intraclass correlation coefficient (ICC)u2009=u20090.92, 95% CI 0.87 to 0.95). Ten stimuli were required to achieve consistent between-session MEP amplitudes among healthy participants (ICCu2009=u20090.89, 95% CI 0.76 to 0.95). However, between-session reliability was influenced by participant characteristics, intersession intervals and target musculature.ConclusionsFurther exploration of the reliability of multi-site TMS mapping is required. Five stimuli produce reliable MEP recordings during single-site TMS investigations involving one session. For single-site analyses involving multiple sessions, ten stimuli are recommended when investigating corticomotor excitability in healthy participants or the upper limb musculature. However, greater numbers of stimuli may be required for clinical populations or assessments involving the lower limb.Systematic review registrationPROSPERO CRD42015024579

Primary Motor Cortex Organization Is Altered in Persistent Patellofemoral Pain

ObjectivenReorganization of the primary motor cortex (M1) may be a feature of persistent patellofemoral pain (PFP), but no studies have investigated M1 organization in this condition. Here we aimed to examine the organization of the M1 representation of the quadriceps muscles in people with PFP and healthy controls.nnnDesignnUsing a cross-sectional design, the M1 representation of the rectus femoris, vastus lateralis, and vastus medialis was mapped using transcranial magnetic stimulation in 11 individuals with PFP and 11 controls. Measures of pain severity were also made.nnnResultsnIndividuals with PFP had reduced map volumes (P < 0.001) and an anterior shift in the M1 representation (Pu2009=u20090.03) across all three quadriceps muscles compared with controls. Greater overlap of the M1 representation (Pu2009=u20090.02) and a reduction in the number of discrete cortical peaks (Pu2009=u20090.009) across all three quadriceps muscles were also observed in individuals with PFP compared with controls. There was no relationship between altered M1 organization and pain in PFP.nnnConclusionsnThese findings provide evidence of altered M1 organization in individuals with PFP compared with healthy controls. Notably, no difference in M1 organization was observed for the medial and lateral heads of the quadriceps in PFP. These data have relevance for our understanding of the pathophysiology of PFP and for the design of future treatments that aim to target M1 in this condition.

Determining the number of stimuli required to reliably assess corticomotor excitability and primary motor cortical representations using transcranial magnetic stimulation (TMS): a protocol for a systematic review and meta-analysis

BackgroundTranscranial magnetic stimulation (TMS) is a technique that can be used to assess corticospinal plasticity. Current TMS practices involve the administration of multiple stimuli over target areas of the participant’s scalp. However, these procedures require 1 to 2xa0h per assessment. Decreasing the number of stimuli delivered during TMS assessments would improve time efficiency and decrease participant demand. Thus, the aim of this review is to determine the number of TMS stimuli required to reliably measure (1) corticomotor excitability to a target muscle at a single cranial site and (2) the topography of the primary motor cortical representation for a target muscle across multiple cranial sites (termed ‘mapping’).Methods/designA systematic review and meta-analysis will be conducted. Electronic databases will be searched using pre-determined search terms to identify relevant studies and evaluate the studies for inclusion and risks of bias. Two independent reviewers will extract the data. Any disagreements will be resolved by a third reviewer. Studies employing single-pulse TMS to measure (1) corticomotor excitability at a single cranial site or (2) the topographic cortical organisation of a target muscle across a number of cranial sites, published before May 2015, will be included if they meet the eligibility criteria. Outcomes will include motor-evoked potential amplitude, map volume, number of active map sites, location of the map centre of gravity, and distance between the centres of gravity of the target muscle and one or more neighbouring muscles.DiscussionTo our knowledge, this review will be the first to systematically explore the number of TMS stimuli required to reliably measure both corticomotor excitability and the topography of primary motor cortical representations. This research has the capacity to improve the efficiency of TMS, decrease participant demand, and facilitate the use of TMS as an outcome measurement tool in clinical populations.Systematic review registrationPROSPERO CRD42015024579

Determining the Optimal Number of Stimuli per Cranial Site during Transcranial Magnetic Stimulation Mapping

The delivery of five stimuli to each cranial site is recommended during transcranial magnetic stimulation (TMS) mapping. However, this time-consuming practice restricts the use of TMS mapping beyond the research environment. While reducing the number of stimuli administered to each cranial site may improve efficiency and decrease physiological demand, doing so may also compromise the procedures validity. Therefore, the aim of this study was to determine the minimum number of stimuli per cranial site required to obtain valid outcomes during TMS mapping. Map volume and centre of gravity (CoG) recordings obtained using five stimuli per cranial site were retrospectively compared to those obtained using one, two, three, and four stimuli per cranial site. For CoG longitude, one stimulus per cranial site produced valid recordings (ICC = 0.91, 95% CI 0.82 to 0.95). However, this outcome is rarely explored in isolation. As two stimuli per cranial site were required to obtain valid CoG latitude (ICC = 0.99, 95% CI 0.99 to 0.99) and map volume (ICC = 0.99, 95% CI 0.99 to 0.99) recordings, it is recommended that a minimum of two stimuli be delivered to each cranial site during TMS mapping in order to obtain valid outcomes.

Anticipatory and compensatory postural adjustments in people with low back pain: a systematic review and meta-analysis

BACKGROUND CONTEXTnDespite altered anticipatory (APAs) and compensatory postural adjustments (CPAs) being hypothesized to contribute to the onset and persistence of low back pain (LBP), results from studies comparing people with and without LBP are conflicting.nnnPURPOSEnThis systematic review aimed to determine whether APAs or CPAs are altered in the presence of acute and chronic LBP.nnnSTUDY DESIGNnA systematic review of studies was carried out.nnnPATIENT SAMPLEnNo patient sample was required.nnnOUTCOME MEASURESnBetween group standardized mean differences and 95% confidence intervals for APAs ad CPAs METHODS: A comprehensive search was conducted for articles comparing people with LBP (acute or chronic) to healthy controls for the onset or amplitude of muscle activity, center of pressure (COP), or kinematic responses to expected or unexpected perturbations. Two independent reviewers extracted data and assessed the methodological quality of relevant studies. Differences between people with and without LBP were calculated as standardized mean differences, and included in a meta-analysis if outcomes were homogeneous. Otherwise, a narrative synthesis was conducted.nnnRESULTSnTwenty-seven studies were included, of which the majority examined muscle onsets in response to expected and unexpected perturbations. Only two studies compared people with and without acute LBP, and results for these studies were conflicting. The results show delayed muscle onsets in response to expected and unexpected perturbations for people with chronic LBP when compared with healthy controls. No conclusive evidence for differences between people with and without chronic LBP for COP or kinematic responses.nnnCONCLUSIONSnThere is currently no convincing evidence of differences between people with and without acute LBP for APAs or CPAs. Conversely, delayed muscle onsets in people with chronic LBP suggest APAs and CPAs are altered in this population. However, the functional relevance of these delayed muscle onsets (eg, COP and kinematics) is unknown.

Fisioterapia guiada por TMS reduz a dor e induz a plasticidade no córtex motor na Osteoartrose Crônica do Joelho

| BACKGROUND: Knee osteoarthritis (OA) is associated with chronic pain, impaired function and loss of quality of life. Maladaptive plasticity of the motor cortex may be involved limiting the beneficial effects of exercises and other interventions. Neuromodulation with peripheral electrical stimulation guided by TMS mapping may specifically influence those maladaptive plasticity. OBJECTIVE: To compare the cortical organization and excitability of three muscles (rectus femoris, vastus lateralis and vastus medialis) in a subject with knee OA. METHODS: This single case (ABA) study involved a 66 years old woman with knee OA that was considering an arthroplasty. She was assessed for pain (VAS), function (WOMAC, ICOAP), and quadriceps strength once a week, for 10 weeks (A – four weeks assessment; B – two weeks assessment and intervention; A – four weeks assessment). TMS mapping was performed at baseline, after the two-week intervention period and at the end of the study. The baseline examination revealed less volume of the vastus medialis portion of the quadriceps muscle over the primary motor cortex (M1), which determined a peripheral electrical stimulation protocol specifically designed to increase this muscle’s excitability. During the intervention period the participant also performed other specific exercises daily. RESULTS: WOMAC scores, and quadriceps strength were not changed during the study period. However, improvements were seen in the three subscales of the ICOAP following the intervention. This clinical change was associated with an increase in vastus medialis and also vastus lateralis, and a decrease in rectus femoris TMS map volumes, which were maintained until the last evaluation. CONCLUSION: TMS mapping may guide specific interventions to counteract motor cortex maladaptive plasticity and positively influence pain and function in knee OA.

Keep the momentum going: pushing the boundaries of clinical learning and assessment

The tertiary education sector in Australia and New Zealand has undergone rapid, sometimes unsettling, change in the last 20 years. The sector now faces a complex array of challenges impacted upon by national and international competition, globalisation, digital disruption, the changing expectations of the student body, and the threat of deregulation. However, entry-level physiotherapy education continues to thrive in this constantly evolving environment, and faces challenges ‘head on’ by providing innovative solutions to some of the stressors, strains and barriers felt by both physiotherapy academics and clinicians. This editorial argues that while this relentless change may often be difficult to adjust to, novel and innovative solutions to the many challenges faced in the provision of physiotherapy education provide breakthroughs that may not be possible if reliant on traditional, sometimes deeply entrenched, ways of thinking and doing things. In the current higher education environment, physiotherapy remains a highly popular career choice and, as a consequence, the number of entry-level programs provided by Australian and New Zealand universities has continued to rise. In 2005, the Australian Council of Physiotherapy Regulating Authorities (ACOPRA) reported that there were 20 programs in Australia and New Zealand. Today, 38 programs are offered by 22 Australian and New Zealand universities, which is a 90% increase in 13 years. In addition, five new programs have indicated that they are applying for accreditation, making a total of 43, as shown in Figure 1. The rate of growth in the number of programs has slowed a little since the period between 1995 and 2005, when the number of physiotherapy programs increased from eight to 20, a 150% increase in 10 years. While growth in the number of programs may be slowing a little, the number of students enrolled in these programs has increased and the types of educational offerings have diversified to differentiate universities in this competitive market. Now, there are multiple entry points into physiotherapy including Bachelor, Bachelor with Honours, graduate entry Masters, and extended graduate entry Masters degrees, with some universities offering the same program at a number of different campuses. Growth in the number of programs and student load within each program has always created questions about access to appropriate clinical placements for students. In 2005, for example, concerns were expressed that the increase in student numbers could mean that some students would be unlikely to have access to a comprehensive program of supervised clinical practice. The pressure on clinical practice sites from the growing number of students was, and remains, a significant concern for the profession. However, when systems and people are under pressure, innovation is required rather than resting on one’s laurels. One solution that has emerged is simulation-based education, predominately in the form of simulated patients portrayed by professional actors. As physiotherapy academics embraced simulation-based education, the prevailing view was that clinical education would not be removed from curricula, but rather that simulation-based education would supplement and enhance traditional clinical experiences. To this end, a large multicentre, nationally funded study was developed by some key physiotherapy academic leaders in partnership with the Australian Physiotherapy Association, the Australian Physiotherapy Council, registration boards, Laerdal Medical Australia, and Health Departments. The research program involved four randomised controlled trials that investigated the effect on students achieving clinical competencies when 1 week of a 4-week traditional clinical placement was replaced with simulation-based education using simulated patients. These landmark publications provided the first tangible, high-quality evidence in physiotherapy that clinical education using simulation could replace 25% of clinical time with real clients without compromising students’ attainment of the professional competencies required to practise. While providing strong empirical evidence, this research program also demonstrated that big strides can be made in the academic and clinical landscape when academic leaders work in partnership with professional bodies. This seminal work was then followed by a large-scale national project, supported financially by the now obsolete Health Workforce Australia, that rolled out simulation-based learning, using mostly professional actors as patients, into 16 physiotherapy programs in Australia between 2014 and 2015. Approximately 1800 physiotherapy students participated in the project, completing 13 200 days of simulation-based training across three core areas of physiotherapy practice: cardiorespiratory, neurological and musculoskeletal physiotherapy. As a consequence, simulation has now become a significant and accepted part of most entry-level physiotherapy curricula in Australia and New Zealand. For the first time in the physiotherapy profession’s history, simulation is currently being trialled as an alternative assessment of competence to practise for physiotherapists with overseas qualifications wishing to work in Australia. The Australian Physiotherapy Council, the body responsible for the assessment of overseas-qualified physiotherapists seeking to work in Australia, has designed a scientifically robust trial in conjunction with academics across Australia to determine whether simulation is as valid an evaluation as the final, single-event comprehensive assessment currently conducted on real patients. In doing so, the Australian Physiotherapy Council has developed a state of the art Journal of Physiotherapy 64 (2018) 205–207

The reliability and validity of rapid transcranial magnetic stimulation mapping

BACKGROUNDnTraditional transcranial magnetic stimulation mapping involves systematically delivering stimuli over a predefined grid. The pseudorandom walk method seeks to improve map acquisition times by abandoning the grid in favour of delivering stimuli randomly over a given area.nnnOBJECTIVESnTo i) determine the minimum interstimulus interval (ISI) required for reliable mapping outcomes within and between sessions using the pseudorandom walk method and ii) assess the validity of the pseudorandom walk method by testing its equivalence with traditional mapping.nnnMETHODSnMaps collected using the pseudorandom walk method at four ISIs (4, 3, 2, and 1s) were compared to maps collected using traditional mapping in twenty healthy individuals. Outcomes included map area, volume, centre of gravity, mean MEP amplitude, and number of discrete peaks.nnnRESULTS AND CONCLUSIONSnThe pseudorandom walk method was valid and reliable with a 2-second ISI for all outcomes except number of discrete peaks, which was less reliable than other measures.

Which learning activities enhance physiotherapy practice? A systematic review protocol of quantitative and qualitative studies

BackgroundLearning activities are fundamental for the development of expertise in physiotherapy practice. Continuing professional development (CPD) encompasses formal and informal learning activities undertaken by physiotherapists. Identifying the most efficient and effective learning activities is essential to enable the profession to assimilate research findings and improve clinical skills to ensure the most efficacious care for clients. To date, systematic reviews on the effectiveness of CPD provide limited guidance on the most efficacious models of professional development for physiotherapists. The aim of this systematic review is to evaluate which learning activities enhance physiotherapy practice.MethodsA search of Ovid MEDLINE, EMBASE, Cumulative Index to Nursing and Allied Health Literature (CINAHL), PsycINFO (Psychological Abstracts), PEDro, Cochrane Library, AMED and Educational Resources and Information Center (ERIC) will be completed. Citation searching and reference list searching will be undertaken to locate additional studies. Quantitative and qualitative studies will be included if they examine the impact of learning activities on clinician’s behaviour, attitude, knowledge, beliefs, skills, self-efficacy, work satisfaction and patient outcomes. Risk of bias will be assessed by two independent researchers. Grading of Recommendations Assessment, Development, and Evaluation (GRADE) and Confidence in the Evidence from Reviews of Qualitative research (CERQual) will be used to synthesise results where a meta-analysis is possible. Where a meta-analysis is not possible, a narrative synthesis will be conducted.Systematic review registrationPROSPERO CRD42016050157

Temporal and spatial characteristics of post-silent period electromyographic bursting in low back muscles: comparison between persons with and without low back pain

ABSTRACT Purpose/aim: Recently, a novel measure of cortical disinhibition was identified using transcranial magnetic stimulation (TMS). This measure, described as post-silent period electromyographic (EMG) bursting, may inform on the corticomotor control of movement in health and disease; however, it has not been investigated for muscles outside the hand or in musculoskeletal conditions. Thus, the aim of this study was to investigate the temporal and spatial characteristics of “EMG bursting” in individuals with and without low back pain (LBP). Materials and Methods: TMS was used to map the motor cortical representation of paraspinal muscles in 11 individuals with LBP and 11 pain-free controls. The latency, duration and magnitude of bursting, number of active burst sites, map volume and coordinates of the burst “hotspot” were compared between the groups. Results: In pain-free controls, the latency, duration and magnitude of bursts were similar to the hand; however, bursts occurred earlier and were of smaller magnitude in LBP. Bursting was widespread throughout the cortical representation in both groups; however, there was a trend towards smaller mean EMG burst and map volume in LBP. Conclusions: We confirm the presence of EMG bursting in back muscles and provide a description of the spatial profile of this mechanism. Our observations in LBP suggest that cortical disinhibition may be altered in this condition.