Broadway office: 02 9514 7222; Moore Park lab: 02 9514 4039
Alana is a lecturer in the Graduate School of Health, Discipline of Physiotherapy. Her research in the Clinical Neurostimulation Laboratory uses noninvasive brain stimulation techniques in humans to better understand neurological movement disorders such as stroke and dystonia.
Previously, Alana completed her PhD in the Movement Neuroscience Lab at the University of Auckland Sport & Exercise Science department and moved to UTS as a postdoctoral research fellow.
Alana is a subject-coordinator for Research Projects 1 & 2 in the Masters of Physiotherapy course where she guides the students in the design, ethics, data collection, analysis, and dissemination of a group research project.
Find her on Research Gate:
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Can supervise: YES
GSH Physiotherapy Research Projects 1 and 2 (96086, 96092)
Key teaching areas:
- Research methods
Boyce, MJ, Kennedy, DS & McCambridge, AB 2020, 'Letter to the Editor, "A randomized study of botulinum toxin versus botulinum toxin plus physical therapy for treatment of cervical dystonia"', Parkinsonism & Related Disorders.View/Download from: Publisher's site
McCambridge, AB, Hay, K, Levin, K, Philpott, K, Wood, K & Bradnam, LV 2020, 'Neck rotation modulates motor-evoked potential duration of proximal muscle cortical representations in healthy adults.', Experimental brain research.View/Download from: Publisher's site
Transcranial magnetic stimulation (TMS) produces motor-evoked potentials (MEP) used to infer changes in corticomotor excitability. In humans, neck rotation can probe reticulospinal input on corticomotor output. This study investigated the effect of neck rotation on MEP duration in a proximal and distal upper limb muscle and compared responses between rest and preactivation. Single-pulse TMS to motor cortex was used to evoke MEPs at two stimulus intensities in 18 healthy adults (20-40 years). Surface electromyography recorded MEPs from the non-dominant biceps brachii (BB) and first dorsal interosseous (FDI). Participants were seated with the target muscle at rest or 10% preactivated, and head rotated ipsilateral, contralateral, or in neutral position. The primary outcome was MEP tail, defined as the mean difference in MEP duration between active and rest trials. Secondary outcomes were MEP duration and amplitude. MEP tail was modulated by neck rotation in the proximal BB (P = 0.03) but not distal FDI (P > 0.19), with shorter duration during ipsilateral or contralateral rotation relative to neutral. In a neutral neck position, MEP duration was prolonged by muscle preactivation and higher TMS intensities in the FDI and BB (P < 0.03). Neck rotation attenuated the prolongation of MEP duration during preactivation in the BB, but not the FDI. Neck rotation had no effect on MEP amplitude for either muscle (P > 0.05). Modulation of the late portion of the MEP by rotation of the neck could indicate subcortical projections to alpha-motoneuron pools are stronger in proximal than distal upper limb muscles. These findings may have relevance for using MEP duration as a neural biomarker in neurological diseases.
McCambridge, A, Meiring, RM & Bradnam, LV 2019, 'Physical Activity, Sedentary Behavior, and Barriers to Exercise in People Living With Dystonia.', Frontiers in Neurology, vol. 10.View/Download from: Publisher's site
Background: Dystonia is a neurological movement disorder that presents as sustained or intermittent involuntary muscle contractions causing abnormal postures and movements. Knowledge of dystonia is mostly at the impairment level with minimal understanding of activity and participation limitations. Physical activity (PA) is an important aspect of neurological disease management, with wide-ranging benefits for overall health and quality of life. No studies have quantified PA and sedentary behavior (SB), nor explored barriers to being physically active in people with dystonia. Methods: Participants diagnosed with any form of dystonia completed a mixed-methods anonymous online survey on activity behaviors. The International Physical Activity Questionnaire (IPAQ) and Adult Sedentary Behavior Questionnaire (SBQ) assessed self-reported PA and SB. Barriers to exercise engagement were investigated according to the five-factor social-ecological framework and dystonia-specific questions regarding the impact of exercise on symptoms were included. Results: Two-hundred and sixty-three participants consented to the study (mean (SD) age = 55 (13) years, 76% Female). A large proportion of respondents (40%) reported living with cervical dystonia (CD). Overall, the median (IQR) time spent in walking, moderate, and vigorous activity was 60 (0-120), 120 (15-300), and 0 (0-13) min/day, respectively. SB time during weekdays was 285.0 (157.5-465.0) min/day and 345.0 (195.0-502.5) min/day on weekends. Fifty-five percent of participants were dissatisfied with their current level of PA and 75% reported dystonia had decreased their level of PA. Fifty-seven percent found their symptoms were worsened during exercise though the after-effects on symptoms varied. Fatigue, motor symptoms, pain, and poor balance were commonly cited limiting factors. Qualitative and quantitative data indicated difficulties with more vigorous intensity activity. The common barriers to engagement were personal and go...
McCambridge, AB, Zaslawski, C & Bradnam, LV 2019, 'Investigating the mechanisms of acupuncture on neural excitability in healthy adults.', NeuroReport, vol. 30, no. 2, pp. 71-76.View/Download from: Publisher's site
Acupuncture is gaining interest as a potential treatment modality for various neurological conditions. Yet, the underlying mechanisms and efficacy on brain function are not well understood. Therefore, this study investigated the previously proposed hypothesis that acupuncture suppresses motor cortex excitability using transcranial magnetic stimulation (TMS) in healthy adults. The study was randomised, sham-controlled, and double-blinded. Single and paired-pulse TMS was delivered before, during, immediately after, and 30 min after removal of the needle. Acupuncture to the right Hegu acupoint (LI-4) of the hand was delivered by an experienced acupuncturist using standardised manipulations. A disposable (0.22×30 mm, Hwato) needle was used for verum stimulation (penetrating) and a Park retractable needle for sham (nonpenetrating). The peak-to-peak amplitude of TMS-induced motor-evoked potentials was recorded from two intrinsic hand muscles. Needling sensations were quantified using the Massachusett's acupuncture sensation scale. Participant needling sensations were not different between verum or sham acupuncture (P>0.54). Corticomotor excitability, intracortical inhibition, and intracortical facilitation were not modulated by verum or sham acupuncture during, immediately after, or 30 min after, recorded from a local or distant hand muscle to the needling site (all P>0.075). Contrary to previous studies, manual acupuncture did not affect motor cortex excitability in healthy adults. Because of the increasing popularity of acupuncture therapy, further research using patient populations should be considered.
Miterko, LN, Baker, KB, Beckinghausen, J, Bradnam, LV, Cheng, MY, Cooperrider, J, DeLong, MR, Gornati, SV, Hallett, M, Heck, DH, Hoebeek, FE, Kouzani, AZ, Kuo, S-H, Louis, ED, Machado, A, Manto, M, McCambridge, AB, Nitsche, MA, Taib, NOB, Popa, T, Tanaka, M, Timmann, D, Steinberg, GK, Wang, EH, Wichmann, T, Xie, T & Sillitoe, RV 2019, 'Consensus Paper: Experimental Neurostimulation of the Cerebellum.', Cerebellum (London, England), vol. 18, no. 6, pp. 1064-1097.View/Download from: Publisher's site
The cerebellum is best known for its role in controlling motor behaviors. However, recent work supports the view that it also influences non-motor behaviors. The contribution of the cerebellum towards different brain functions is underscored by its involvement in a diverse and increasing number of neurological and neuropsychiatric conditions including ataxia, dystonia, essential tremor, Parkinson's disease (PD), epilepsy, stroke, multiple sclerosis, autism spectrum disorders, dyslexia, attention deficit hyperactivity disorder (ADHD), and schizophrenia. Although there are no cures for these conditions, cerebellar stimulation is quickly gaining attention for symptomatic alleviation, as cerebellar circuitry has arisen as a promising target for invasive and non-invasive neuromodulation. This consensus paper brings together experts from the fields of neurophysiology, neurology, and neurosurgery to discuss recent efforts in using the cerebellum as a therapeutic intervention. We report on the most advanced techniques for manipulating cerebellar circuits in humans and animal models and define key hurdles and questions for moving forward.
Lee, M & McCambridge, A 2018, 'Clinimetrics: Amyotrophic Lateral Sclerosis Functional Rating Scale-revised (ALSFRS-R)', Journal of Physiotherapy, vol. 64, no. 4, pp. 269-270.View/Download from: Publisher's site
McCambridge, AB, Stinear, JW & Byblow, WD 2018, 'Revisiting interhemispheric imbalance in chronic stroke: A tDCS study.', Clinical Neurophysiology, vol. 129, no. 1, pp. 42-50.View/Download from: Publisher's site
Chronic stroke patients with moderate-severe motor impairment may have an increased reliance on contralesional vs ipsilesional motor areas to control the paretic arm. We hypothesised that increasing contralesional excitability with anodal transcranial direct current stimulation (a-tDCS) would benefit motor performance in patients with moderate-severe impairment.Ten patients with motor impairment at the chronic stage after stroke received a-tDCS, cathodal (c-tDCS) and sham with the target electrode over contralesional motor cortex (M1). Motor performance was quantified from the circularity and size of planar movements made with the paretic arm. Contralateral and ipsilateral corticospinal excitability was inferred using transcranial magnetic stimulation. Corticospinal tract integrity and basal GABA concentration were assessed with magnetic resonance imaging and spectroscopy.Anodal tDCS increased contralesional corticomotor excitability evident from motor evoked potentials in both wrist extensors (both P<0.043). Cathodal tDCS did not affect corticomotor excitability (P>0.37). The effect of tDCS on motor performance with the paretic limb was negatively associated with ipsilesional GABA concentration after c-tDCS (P=0.001).Further investigation of noninvasive brain stimulation protocols that facilitate contralesional M1 is warranted.The inter-hemispheric imbalance model of stroke recovery may not apply to patients with more severe impairment.
McCambridge, AB, Stinear, JW, Peek, S & Byblow, WD 2017, 'Propriospinal cutaneous-induced EMG suppression is unaltered by anodal tDCS of healthy motor cortex', Clinical Neurophysiology, vol. 128, no. 9, pp. 1608-1616.View/Download from: Publisher's site
© 2017 International Federation of Clinical Neurophysiology Objective Cervical propriospinal premotoneurons (PN) relay descending motor commands and integrate peripheral afferent feedback. Effects of anodal transcranial direct current stimulation (a-tDCS) on propriospinal excitability in the upper limbs are unknown. Methods Healthy right-handed adults received a-tDCS or sham tDCS over primary motor cortex (M1) at 1 mA (Experiment 1, n = 18) or 2 mA current intensity (Experiment 2, n = 15). Propriospinal excitability was assessed by suppression of background electromyography (EMG) in extensor carpi radialis (ECR) from electrical stimulation of the superficial radial nerve during bilateral (Experiment 1 and 2) or unilateral (Experiment 2 only) activation of the left and/or right ECR. EMG suppression could be attributed to an early propriospinal component and late cortical component. Motor evoked potentials (MEP) were obtained as a manipulation check. Results Before tDCS, propriospinal-mediated cutaneous-induced suppression was present in each arm for early and late components. ECR MEP amplitude increased after 1 mA, but not 2 mA, a-tDCS. Neither 1 mA nor 2 mA a-tDCS modulated either component of ipsilateral or contralateral propriospinal excitability during bilateral or unilateral tasks. Conclusions Propriospinal-mediated cutaneous-induced suppression was not modulated by a-tDCS in healthy adults. Significance Reporting non-significant findings is paramount for the development of clinically-relevant tDCS protocols.
McCambridge, AB, Stinear, JW & Byblow, WD 2016, 'Are ipsilateral motor evoked potentials subject to intracortical inhibition?', Journal of Neurophysiology, vol. 115, no. 3, pp. 1735-1739.View/Download from: Publisher's site
McCambridge, AB, Stinear, JW & Byblow, WD 2016, 'Neurophysiological and behavioural effects of dual-hemisphere transcranial direct current stimulation on the proximal upper limb', Experimental Brain Research, vol. 234, no. 6, pp. 1419-1428.View/Download from: Publisher's site
Kersten, P, McCambridge, A, Kayes, NM, Theadom, A & McPherson, KM 2015, 'Bridging the gap between goal intentions and actions: a systematic review in patient populations', DISABILITY AND REHABILITATION, vol. 37, no. 7, pp. 563-570.View/Download from: Publisher's site
Kersten, P, McPherson, KM, Kayes, NM, Theadom, A & McCambridge, A 2015, 'Bridging the goal intention-action gap in rehabilitation: a study of if-then implementation intentions in neurorehabilitation', DISABILITY AND REHABILITATION, vol. 37, no. 12, pp. 1073-1081.View/Download from: Publisher's site
McCambridge, AB, Stinear, JW & Byblow, WD 2015, ''I-wave' Recruitment Determines Response to tDCS in the Upper Limb, but Only So Far', BRAIN STIMULATION, vol. 8, no. 6, pp. 1124-1129.View/Download from: Publisher's site
McCambridge, AB, Stinear, JW & Byblow, WD 2014, 'A dissociation between propriospinal facilitation and inhibition after bilateral transcranial direct current stimulation.', Journal of Neurophysiology, vol. 111, no. 11, pp. 2187-2195.View/Download from: Publisher's site
Propriospinal premotoneurons (PN) are essential for accurate control of the upper limb. They receive bilateral input from premotor (PM) and primary motor (M1) cortices. In humans, excitability of PNs can be estimated from motor-evoked potentials (MEPs) by pairing a descending volley using transcranial magnetic stimulation (TMS) to summate with an ascending volley from peripheral nerve stimulation at the C3-C4 level of the spinal cord. Transcranial direct current stimulation (tDCS) alters excitability of cortical and subcortical areas. A recent study demonstrated that cathodal tDCS can suppress facilitatory (FAC) and inhibitory (INH) components of PN excitability, presumably via effects on corticoreticulospinal neurons (Bradnam LV, Stinear CM, Lewis GN, Byblow WD. J Neurophysiol 103: 2382-2389, 2010). The present study investigated the effects of bilateral tDCS with healthy subjects. The cathode was placed over left dorsal PM or M1 and the anode over right M1 in separate sessions (PM-M1, M1-M1, or Sham). TMS of right M1 elicited MEPs in left biceps brachii across a range of TMS intensities chosen to examine PN-mediated FAC and INH. Conditioning was applied using median nerve stimulation with an interstimulus interval that coincided with TMS and peripheral volleys summating at the C3-C4 level. All participants showed FAC at TMS intensities near active motor threshold and INH at slightly higher intensities. After tDCS, FAC was reduced for M1-M1 compared with Sham but not after PM-M1 stimulation. Contrary to an earlier study with cathodal tDCS, INH was unchanged across all sessions. The difference between these and earlier findings may relate to dual- vs. single-hemisphere M1 stimulation. M1-M1 tDCS may be a useful adjuvant to techniques that aim to reduce upper limb impairment after stroke.
Byblow, WD, Stinear, CM, Smith, M-C, Bjerre, L, Flaskager, BK & McCambridge, AB 2012, 'Mirror Symmetric Bimanual Movement Priming Can Increase Corticomotor Excitability and Enhance Motor Learning', PLOS ONE, vol. 7, no. 3.View/Download from: Publisher's site
Biddle, M, Vincent, G, McCambridge, AB, Britton, G, Dewes, O, Elley, CR, Moyes, SA & Edge, J 2011, 'Randomised controlled trial of informal team sports for cardiorespiratory fitness and health benefit in Pacific adults', Journal of Primary Health Care, vol. 3, no. 4, pp. 269-277.
Introduction: Rates of obesity, Type 2 diabetes and cardiovascular disease are high among Pacific
people in New Zealand. Physical activity is recommended in the prevention and management of these
conditions. Community-based, 'small-sided game' group activities may be an effective and culturally appropriate
way to promote physical activity within Pacific communities.
Aim: To assess the effectiveness of small-sided games-based exercise on fitness and health parameters
among Pacific adults over four weeks.
Methods: Twenty untrained (13 female) Pacific adults were randomised to intervention or control.
Intervention participants were offered 45 minutes of small-sided games three times per week for four
weeks. Control participants were offered one-month gym membership after the trial. Primary outcomes
included cardiorespiratory fitness (VO2
peak) and leg strength (maximal concentric force of quadriceps at
60°/second) measured at baseline and four weeks. Secondary outcomes included glycaemia, lipid profile,
blood pressure (BP), and inflammatory markers. Multivariable regression models were used to assess
differences between groups, adjusting for baseline values, age and gender.
Results: At baseline, mean age was 34.8 years (SD 12.6), BMI 36.3 (6.7), systolic BP 127.7 mmHg
(12.1), HbA1c 6.1% (1.9), VO2
peak 2.5 L/min (0.6) and leg strength 170.0 N.m (57.4). Sixteen participants
completed the trial. Change in outcomes were greater in intervention than control participants in absolute
peak (0.9 L/min (p=0.003)), leg strength (17.8 N.m (p=0.04)) and HDL (0.12 mmol/L (p=0.02)). There
were no other significant differences.
DISCUSSION: Small-sided games appear to be a promising means for improving the health and cardiorespiratory
fitness and reducing the risk of diabetes and cardiovascular disease in Pacific adults.
KEYWORDS: Exercise; diabetes mellitus, Type 2; Pacific Islands; randomized controlled trial; health
McCambridge, AB & Hordacre, B 2018, 'Motor control: structure & function of the nervous system' in Lennon, S, Ramdhary, G & Verheyden, G (eds), Neurological Physiotherapy Pocketbook.
McCambridge, A & Bradnam, L 2018, 'S63. Cerebellar stimulation for adults with cervical dystonia: A tDCS study', International Congress of Clinical Neurophysiology, Washington, pp. 165-165.View/Download from: Publisher's site
Cervical dystonia (CD) is characterized by painful, involuntary twisting of the neck, and sometimes tremor. Unfortunately, treatment options for CD are limited and the underlying pathophysiology is not well understood. Recent evidence implicates cerebellar dysfunction may play a role in the development of CD symptoms. Non-invasive brain stimulation is able to modulate neural excitability of the cerebellum.
The present study examined the effect of five consecutive days of anodal transcranial direct current stimulation (tDCS) over the cerebellum of adults with CD (2 mA, 20 min). Patients received five sessions of anodal tDCS and sham tDCS in a randomised, cross-over design that was double-blinded. During tDCS, patients performed a motor imagery task (first 10 min) and a real movement task (last 10 min). We hypothesised that anodal tDCS would improve patient's clinical features and modulate neural excitability of the cerebellum. Clinical features were examined using the TWSTRS2, CDQ-24, cervical range of motion, and visual analogue scales of pain. Behavioural outcomes were assessed using a motor learning finger tracking task. Neural excitability was inferred using eye-blink conditioning to examine cerebellar excitability and single-pulse transcranial magnetic stimulation (TMS) over the motor cortex to examine corticomotor excitability and intracortical inhibition. Motor evoked potentials (MEP) and cortical silent periods (cSP) were recorded bilaterally from the upper trapezius (UT) and first dorsal interosseous (FDI) muscles. All dependent measures were assessed on day-1 and day-5 of the intervention, and follow up questionnaires were completed one and four weeks later. There was a minimum washout period of 5 weeks between treatment blocks, and patients undergoing Botox were tested 4 weeks post injections.
The study is in the late stages of data collection and analysis (n = 14 patients enrolled, 8 males).
The outcome of thi...
Acupuncture is a therapeutic technique that is being used as an adjuvant to treatment in a variety of health-related disorders. However despite its increasing use in western countries, the underlying mechanisms are not fully understood. The aim of this study is to investigate the underlying neurophysiological mechanisms of acupuncture by examining the effect of real (verum) and sham acupuncture to the hand on the excitability of the motor cortex (M1) in healthy adults. A better understanding of the underlying mechanisms of acupuncture may improve the potential therapeutic application of acupuncture for neurological disorders in the future.
Healthy, right-handed, adults with no neurological or musckuloskeletal conditions participated in the study. Participants were randomised to receive verum or sham acupuncture to the Hegu acupoint of the hand on separate days, with a minimum 5 day washout. The intervention type was double-blinded, and the acupuncturist was not involved in data collection or analysis. Transcranial magnetic stimulation (TMS) was delivered to the left M1 and surface electromyography was used to record TMS-induced responses from the First Dorsal Interossues (FDI) and Adductor Digiti Minimi (ADM). Stimulus-response curves, short-intracortical inbhition (SICI-2 ms) and intracortical facilitaiton (ICF-15 ms) were measured before, during, immediately after needle removal, and 30 min after needle removal. Needling sensation questionnaires were administered after each session, and self-rated anxiety was assessed before, during and after needle removal.
Relative to sham, verum acupuncture did not modulate corticomotor or intracortical excitability in either muscle across time (all P > 0.05). There were no differences in the severity of needling sensations between sessions (all P > 0.05), therefore sham park needle acupuncture was likely an adequate sham control.
There was little-to-no evidence that acupuncture to ...
McCambridge, AB, Stinear, JW & Byblow, WB 2015, '"I-wave" recruitment predicts response to tDCS in the upper limb, but only so far', Brain Stimulation, Elsevier, Singapore, pp. 357-357.View/Download from: Publisher's site
McCambridge, AB, Stinear, JW & Byblow, WB 2014, 'P647: A dissociation between propriospinal facilitation and inhibition after bilateral transcranial direct current stimulation', Journal of Clinical Neurophysiology, ICCN, Lippincott, Williams & Wilkins, Berlin, pp. S226-S226.
McCambridge, A Accident Compensation Corporation (ACC) 2011, A review of community and social integration & a critique of frameworks of measurement in rehabilitation., New Zealand.
McCambridge, A Accident Compensation Corporation (ACC) 2011, Review of Outcome Measurement in Injury Rehabilitation (Update of Return to Work measures and review of Participation)., New Zealand.
McCambridge, AB, 'Ipsilateral Motor Evoked Potentials and Intracortical Inhibition'.
Seeking to better understand the role of ipsilateral primary motor cortex during functional motor tasks, Byblow and colleagues examined whether ipsilateral motor evoked potentials (iMEPs) in the biceps brachii would be suppressed by sub-threshold conditioning, thereby demonstrating short-interval intracortical inhibition of iMEPs. In this podcast, Editor-in-Chief Bill Yates (University of Pittsburgh) and Associate Editor Monica A. Perez (University of Miami) join authors Winston Byblow (University of Auckland) and Alana McCambridge (University of Auckland) in an engaging discussion about their recent work. Are ipsilateral motor evoked potentials subject to intracortical inhibition? Listen and find out.