Shapour Jaberzadeh

Shapour Jaberzadeh
Monash University (Australia) · Department of Physiotherapy

BSc (Phty), MSc (Phty), MAppSc (Manip Phty), GCHPE, PhD

About

195
Publications
33,222
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
3,471
Citations
Citations since 2016
126 Research Items
2925 Citations
20162017201820192020202120220100200300400500600
20162017201820192020202120220100200300400500600
20162017201820192020202120220100200300400500600
20162017201820192020202120220100200300400500600
Introduction

Publications

Publications (195)
Article
Full-text available
Transcranial direct current stimulation (tDCS) applied to the primary motor cortex (M1), and cerebellum (CB) can change the level of M1 corticospinal excitability (CSE). A randomized double-blinded crossover, the sham-controlled study design was used to investigate the effects of concurrent bilateral anodal tDCS of M1 and CB (concurrent bilateral a...
Article
Sustained performance of cognitive tasks could lead to the development of state mental fatigue characterized by subjective sensation of mental weariness and decrease in cognitive performance. In addition to the occupational hazards associated with mental fatigue, it can also affect physical performance reducing endurance, balance, and sport-specifi...
Article
Postural impairment is one of the most disorders in patients with multiple sclerosis (MS), while fear of falling can exacerbate it in these patients. One of the leading causes of postural impairment and fear of falling in patients with MS is the cerebellum region's abnormalities, which may be modulated by cerebellar anodal transcranial direct curre...
Article
Purpose: Postural instability can increase the risk of a fall in older adults. In this study, the impact of mental fatigue on postural stability among healthy older adults was investigated. Method: Participants were randomly divided into two groups: experimental and control groups. Postural stability of all participants was tested using the Biodex...
Article
Full-text available
Exercise performance (EP) is affected by a combination of factors including physical, physiological, and psychological factors. This includes factors such as peripheral, central, and mental fatigue, external peripheral factors such as pain and temperature, and psychological factors such as motivation and self-confidence. During the last century, nu...
Article
Full-text available
The dual task experimental paradigm is used to probe the attentional requirements of postural control. However, findings of dual task postural studies have been inconsistent with many studies even reporting improvement in postural stability during dual tasking and thus raising questions about cognitive involvement in postural control. A U-shaped no...
Preprint
Full-text available
Sustained performance of cognitive tasks could lead to the development of state mental fatigue characterized by subjective sensation of mental weariness and decrease in cognitive performance. In addition to the occupational hazards associated with mental fatigue, it can also affect physical performance reducing endurance, balance, and sport-specifi...
Article
Introduction Stretching and strengthening exercises are commonly used to improve muscle shortness. Consequently, the aim of this trial was to compare the flexion-relaxation response (electromyography activities of shortened hamstring and back muscles) in chronic nonspecific LBP patients. Methods In this randomized controlled clinical trial, forty-...
Article
Introduction: Transcranial pulsed current stimulation (tPCS) could be used to deliver electrical pulses at different frequencies to entrain the cortical neurons of the brain. Frequency dependence of these pulses in the induction of changes in corticospinal excitability (CSE) has not been reported. Objective: We aimed to assess the effect of anod...
Article
Full-text available
Context-dependent execution or inhibition of a response is an important aspect of executive control, which is impaired in neuropsychological and addiction disorders. Transcranial direct current stimulation (tDCS) of the dorsolateral prefrontal cortex (DLPFC) has been considered a remedial approach to address deficits in response control; however, c...
Preprint
Our ability to interact flexibly with the surrounding environment and achieve an adaptive goal-directed response is one of the necessities of balance control. This study aimed to examine the interaction between cognitive demand and the necessity for keeping balance in unstable conditions. We examined the effects of performing two cognitive tasks, n...
Article
One of the most common symptoms in stroke patients is spasticity. The aims were to investigate the effects of anodal trans-cranial direct current stimulation (a-tDCS) over the affected primary motor cortex (M1) on ankle plantar flexor spasticity and dorsiflexor muscle activity in stroke patients. The design of this study was a randomized sham-contr...
Article
The issue of using transcranial direct current stimulation (tDCS) to improve sport performance has recently been a topic of interest for researchers. The purpose of this study was to examine the effect of tDCS over left dorsolateral prefrontal cortex (DLPFC) on mental fatigue and physical performance in professional swimmers. Fifteen professional s...
Article
The Corona Virus Disease 19 (COVID-19) pandemic has imposed serious restrictions for academic institutions to maintain their research and teaching practical subjects. Universities have implemented adaptive measures to maintain educational activities and achieve the learning objectives for undergraduate and postgraduate students by shifting to onlin...
Article
Background Neuroimaging studies show that nociceptive stimuli elicit responses in an extensive cortical network. Functional near-infrared spectroscopy (fNIRS) allows for functional assessment of changes in oxyhemoglobin (HbO), an indirect index for cortical activity. Unlike functional magnetic resonance imaging (fMRI), fNIRS is portable, relatively...
Article
Objective To investigate whether unilateral strength training helps improve cortical excitability and clinical outcomes after stroke. Design Randomized controlled trial Setting Rehabilitation sciences research center Participants 26 patients with subacute stroke were randomly assigned to a control group (n=13) or the experimental group (n=13)....
Article
Introduction: High variability between individuals (i.e., interindividual variability) in response to transcranial direct current stimulation (tDCS) has become a commonly reported issue in the tDCS literature in recent years. Inherent genetic differences between individuals have been proposed as a contributing factor to observed response variabilit...
Article
Spasticity is a common symptom in stroke survivors. This study is double-blinded, sham-controlled randomized, clinical trial with three parallel arms. The aim of the study was to investigate the effects of anodal trans-cranial direct current stimulation (a-tDCS) over the damaged primary motor cortex (M1) on spasticity of the wrist flexor and also t...
Article
Genetic mediation of cortical plasticity and the role genetic variants play in previously observed response variability to transcranial direct current stimulation (tDCS) have become important issues in the tDCS literature in recent years. This study investigated whether inter‐individual variability to tDCS was in‐part genetically mediated. In 61 he...
Article
Full-text available
Transcranial direct current stimulation is applied to modulate activity, and excitability of the brain. Basically, LTP-like plasticity is induced when anodal tDCS (a-tDCS) is applied over the primary motor cortex. However, it has been shown that specific parameters of a-tDCS can induce a plasticity reversal. We aimed to systematically assess the in...
Article
Introduction: Transcranial pulsed current stimulation (tPCS) is an emerging noninvasive brain stimulation technique that has shown significant effects on cortical excitability. To date, electrophysiological measures of the efficiency of monophasic tPCS have not been reported. Objective: We aimed to explore the effects of monophasic anodal and cath...
Article
Full-text available
The aim of this study was to examine the effects of 5 days of anodal-transcranial direct current stimulation (a-tDCS) over the primary motor cortex (M1) on lower extremity functional performance in healthy elderly people. This was a randomized, double-blinded, sham-controlled study whereby 32 healthy older individuals participated in two groups. Th...
Article
Transcranial pulsed current stimulation (tPCS) of the human motor cortex has received much attention in recent years. Although the effect of anodal tPCS with different frequencies has been investigated, the effect of cathodal tPCS (c‐tPCS) has not been explored yet. Therefore, the aim of the present study was to investigate the effect of c‐tPCS at...
Preprint
High variability between individuals (i.e. inter-individual variability) in response to transcranial direct current stimulation (tDCS) has become a commonly reported issue in the tDCS literature in recent years. Inherent genetic differences between individuals has been proposed as a contributing factor to observed response variability. This study i...
Article
Response variability following transcranial direct current stimulation (tDCS) highlights need for exploring different tDCS electrode montages. Corticospinal excitability (CSE), cortico-cortical excitability and intra-individual variability was compared following conventional and high-definition (HD) anodal (a-tDCS) and cathodal (c-tDCS) tDCS. Fifte...
Article
Objective To compare the effects of anodal trans-cranial direct current stimulation (a-tDCS) over primary motor and dorsolateral prefrontal cortices on Fatigue Severity Scale and its lasting effect on fatigue reduction and improvement in quality of life in patients with multiple sclerosis. Design A randomized, double-blinded, sham-controlled paral...
Preprint
Genetic mediation of cortical plasticity and the role genetic variants play in previously observed response variability to transcranial direct current stimulation (tDCS) have become important issues in the tDCS literature in recent years. This study investigated whether inter-individual variability to tDCS was in-part genetically mediated. In sixty...
Article
Background With advancing age, changes in the central nervous system may lead to motor functional deficits. Non-invasive Brain stimulation techniques are suggested to help modifing brain function. Objectives The aim of the current study was to investigate the effect of using multi session anodal transcranial Direct Current Stimulation (a-tDCS) ove...
Preprint
Response variability following transcranial direct current stimulation (tDCS) highlights need for exploring different tDCS electrode montages. This study compared corticospinal excitability (CSE), cortico-cortical excitability and intra-individual variability following conventional and HD anodal (a-tDCS) and cathodal (c-tDCS) tDCS. Fifteen healthy...
Article
Objective Multiple Sclerosis (MS) is one of the most common neurological diseases in the world. Due to structural and functional changes in central nerves system, the patients with MS may affected by sensory-motor learning deficits. The aims of the current study was to assess the effect of primary motor cortex (M1) anodal transcranial direct curren...
Article
Response variability between individuals (inter-individual variability) and within individuals (intra-individual variability) is an important issue in the transcranial magnetic stimulation (TMS) literature. This has raised questions of the validity of TMS to assess changes in corticospinal excitability (CSE) in a predictable and reliable manner. Se...
Article
Introduction To overcome the limitations of clinical scales, objective measurement methods are becoming prominent in spasticity assessment. The aim of this study was to assess the test–retest reliability and responsiveness of isokinetic dynamometry to evaluate wrist flexor spasticity in patients with subacute stroke. Methods Twenty six patients wi...
Article
Full-text available
Background Transcranial direct current stimulation (tDCS) is used to induce neuroplasticity in the human brain. Within certain limits of stimulation duration, anodal tDCS (a-tDCS) over the primary motor cortex induces long term potentiation- (LTP) like plasticity. A reversal of the direction of plasticity has however been described with prolonged a...
Article
Various studies have investigated the effect of noninvasive brain stimulation methods such as transcranial direct stimulation (tDCS) on postural control in healthy young and older adults. However, the use of different treatment protocols and outcome measures makes it difficult to interpret the research results. This systematic review provides a com...
Article
Application of unilateral tDCS (Uni-tDCS) vs. bilateral tDCS (Bi-tDCS) is another important factor that can affect the physiological results of tDCS intervention on motor learning and motor performance. According to the evidence, some studies indicated that motor performance or motor learning are facilitated in healthy individuals by application of...
Article
BACKGROUND: Muscle weakness is the most common impairment in the upper extremity (UE) after a stroke. Understanding the relationship between hand strength and functional outcomes would be advantageous in clinical settings for the development of efficient rehabilitation programs. PURPOSE: To determine the relationship of hand strength with paretic UE...
Article
Context: Chronic low back pain (CLBP) often presents with a dysfunction in deep abdominal muscles activity during standing tasks. Although some studies indicated that deep abdominal muscle activity improved during some functional tasks following stabilization exercise (SE), there is no study to evaluate the effect of SE on lateral abdominal muscle...
Article
Objective: High rates of variability in the amplitude of transcranial magnetic stimulation (TMS)-induced motor evoked potentials (MEPs), a popular method for assessing corticospinal excitability (CSE), make it essential to examine inherent reliability of the MEP amplitude. We aimed to investigate the effects of different inter-trial-intervals (ITI...
Article
Full-text available
Purpose Transcranial magnetic stimulation (TMS) usually investigates the corticospinal responses of the agonist muscle to strength training, despite the role of the antagonist muscle in strength development. We examined the intracortical responses from an agonist and antagonist muscle following a single session of heavy-loaded strength training (do...
Article
Full-text available
Recently, there have been several studies that have examined the acute effects of aerobic exercise on cognitive function. Importantly, one precise indicator of cognitive function is response time (RT), which has two main components; premotor time (PMT) and motor time (MT). PMT is the time for perception, decision making and response preparation, wh...
Article
Changes in different regions of the brain due to postural disturbances were found in patients with chronic low back pain (LBP). The aims of the current study were to investigate the short- and long-term enhancing effects of concurrent postural training and primary motor cortex (M1) anodal transcranial direct current stimulation (a-tDCS) on balance,...
Article
Mason, J, Frazer, AK, Jaberzadeh, S, Ahtiainen, JP, Avela, J, Rantalainen, T, Leung, M, and Kidgell, DJ. Determining the corticospinal responses to single bouts of skill and strength training. J Strength Cond Res XX(X): 000-000, 2019-Neuroplastic changes in the primary motor cortex accompany performance improvements following motor practice. Recent...
Article
Background: Postural control impairment is a key target for rehabilitation of older adults with high fall risk. Objective: To investigate whether anodal transcranial direct current stimulation (a-tDCS) over primary motor cortex (M1) or cerebellum can enhance the positive effects of postural training on balance and postural stability in older adu...
Article
Numerous studies have indicated that non-invasive brain stimulation (NIBS) of the cerebellum could modulate corticospinal excitability (CSE) in young healthy individuals. However, there is no systematic review and meta-analysis that clarifies the effects of cerebellar NIBS on CSE. The aim of this study was to provide a meta-analytic summary of the...
Article
The effects of transcranial direct-current stimulation (tDCS) on cognitive functions, such as response inhibition, might be mediated through plastic changes within the prefrontal cortex. Previous studies have also confirmed learning-related plasticity in prefrontal neurocircuitry. The susceptibility of prefrontal neurocircuitry for tDCS-induced pla...
Article
Intensifying fear and fear of pain may lead to some diseases such as panic disorder, phobias, post-traumatic stress disorder (PTSD), anxiety disorders, depression, etc. A number of studies indicated positive effect of transcranial direct current stimulation (tDCS) on controlling fear and some studies did not observe any effect or even negative effe...
Chapter
This chapter describes the methodological considerations for selection of transcranial direct current stimulation (tDCS) approaches, protocols and devices for studies conducted in both healthy individuals and patients with different pathological conditions. The first section of the chapter discusses evidence-based use of tDCS. The second section of...
Article
Full-text available
Study aim : Increased muscle tone, a common consequence of stroke, has neural and non-neural components. Spasticity is related to the neural component. Non-neural resistance arises from passive stiffness. This study was designed to assess the feasibility of using isokinetic dynamometry to evaluate wrist flexor muscle spasticity in stroke patients....
Article
Dear Editor, We appreciated Kang & Cauraugh’ letter (‘A Comment on Postural Stability Improvement in Older Adults with High Fall Risk after Anodal tDCS on Primary Motor Cortex versus Cerebellar Stimulation’) in response to our research article [1]. Kang & Cauraugh’ primary point – the insufficient focal administration of the unilateral anodal tD...
Chapter
Transcranial magnetic stimulation (TMS) is a non-invasive tool for assessment of brain function in health and disease. It can be also used as a therapeutic tool in a number of psychological and neurological conditions. TMS as an assessment tool usually uses single or paired-pulse paradigms and although it is considered as a safe technique it is not...
Article
Background: Supra-threshold scaling of multiple pressure-pain sensations involves delivery of varied stimulus intensities, either via stimulus-dependent or response-dependent manner, and recording of subjective pain ratings by participants. The focus of this study was to determine the intra- and inter-session reliability of pain intensity and pain...
Article
Full-text available
It is believed that unihemispheric concurrent dual-site transcranial direct current stimulation (tDCSUHCDS) of the primary motor cortex (M1) and the dorsolateral prefrontal cortex (DLPFC) causes an increase in motor cortex excitability. However, the clinical effect of this type of stimulation on patients with neurological conditions is not yet know...
Article
Several methods can be used to determine the resting motor threshold (RMT) and by that recording transcranial magnetic stimulation (TMS) induced motor evoked potentials (MEPs). However, no research has compared the test retest reliability of these methods. Thus, the aim of this study was to determine intra‐ and inter‐session reliability of Rossini–...
Article
High degrees of variability reported in Transcranial magnetic stimulation (TMS) assessment of corticospinal excitability (CSE) highlight the need to investigate its reliability as an assessment tool. This study investigated the effect of TMS test intensity on the amplitude, variability and test-retest reliability of motor evoked potentials (MEP). T...
Article
Full-text available
Recently, several studies have used Transcranial Magnetic Stimulation (TMS) to probe the corticospinal-motoneuronal responses to a single session of strength training; however, the findings are inconsistent. This systematic review and meta-analysis examined whether a single bout of strength training affects the excitability and inhibition of intrac...