Name: repeated transcranial magnetic stimulation combined with action observation training in children with spastic cerebral palsy
Uploaded: 2024-08-09T12:40:00.000+00:00
Duration: 7 min 20 s
Description: This study presents the results of a randomized controlled trial utilizing a 2 x 2 factorial design, comparing the effects of repeated transcranial ...

This study was supported by the funding of the Xiangya Boai Rehabilitation Hospital.

This study was carried out in strict accordance with the national standards for human experimentation, and the clinical study was approved by the Ethics Association of Xiangya Boai Rehabilitation Hospital (ethics approval number: 20211223). The children&#39;s guardians agreed to participate in this training program and signed informed consent forms. Children with SCP were recruited in the Xiangya Boai Rehabilitation Hospital and Xiangya Hospital of Central South University from February 2022 to December 2022.
1. Preparation before the experiment
<ol>
	<li>To ensure the accuracy of study results, provide relevant training to rehabilitation therapists and assess their skills in advance to make sure that they can guide the children in the training. 
	NOTE: The rTMS technicians should be trained and qualified to ensure the safety of children.</li>
	<li>Conduct rTMS safety screening with parents before the experiment, including questioning them about evidence of seizures and medications taken. 
	NOTE: Medications can lower the seizure threshold.</li>
</ol>
2. Recruitment
<ol>
	<li>Recruit children with SCP whose clinical diagnosis and classification meet the criteria of China Cerebral Palsy Rehabilitation Treatment Guidelines (2022)21.
	<ol>
		<li>Ensure that the children are between 3 and 6 years old.</li>
		<li>Ensure that the children have Gesell Developmental Diagnostic Scale (GDDS) adaptive behavioral area development quotient (DQ) &#62; 55 so that they can actively participate in training.</li>
		<li>Ensure that the children have Gross motor function classification (GMFCS) I-III.</li>
		<li>Ensure that the children can walk more than 10 m independently or with a walker.</li>
	</ol>
	</li>
	<li>Exclude the following: children with other types of CP; children scheduled for medical rehabilitation or surgery during the study period; children with epilepsy, severe intellectual impairment, visual impairment, or attention deficit; children with cochlear implants or intracranial implants.</li>
	<li>Before the training, obtain informed consent forms from children&#39;s guardians for voluntary participation in this training program 1x a day, 5 days per week for 12 weeks.</li>
</ol>
3. Pretreatment assessment
<ol>
	<li>Analyze the baseline data collected from recruited children with SCP, including name, sex, age, cerebral palsy spasticity type, GMFCS, cognitive level, ankle foot orthosis wear, previous or current medical treatment, and surgical history.</li>
	<li>Rehabilitation assessment 
	NOTE: Studies have shown that the Comprehensive Spasticity Scale (CSS) used to assess the degree of lower limb spasm in children with SCP has good reliability and validity22.
	<ol>
		<li>Determine the degree of spasm by examining the lower limb Achilles tendon reflex, the muscle tension of the ankle plantar flexor group, and the ankle clonus. Use the following evaluation criteria: no spasm, &#60;7; mild spasm, 7-9; moderate spasm, 10-12; and severe spasm, 13-16.</li>
		<li>Assess balance function according to the Pediatric Balance Scale (PBS)23, which includes 14 tested items. Each item is divided into five levels with 0-4 points for each item and 56 points in total. The higher the score, the better the balance function. 
		NOTE: PBS is based on the BBS Children&#39;s Revision, mainly adjusting the order of the tested items, shortening the time for maintaining posture, and clarifying test instructions.</li>
		<li>Assess the children&#39;s walking ability based on the 10 m walking speed (10MWS)24.
		<ol>
			<li>Ask children to walk as fast as possible on a runway with specifications of width x length =20 cm x 15 m, independently or wearing an ankle-foot orthotic or using a walking aid for children with GMFCS class III.</li>
		</ol>
		</li>
		<li>Ask children to start walking at the 15 m marker; start timing at 12 m, and stop at 2 m to measure the time taken for the middle 10 m. Ask the children to perform three consecutive 10MWT tests and calculate the walking speed (m/s). 
		NOTE: The functional level of the children was graded I-III according to GMFCS, meaning they have certain standing and walking ability.</li>
		<li>Evaluate the gross motor function level of the children by selecting a standing position in area D (13 items) and walking, running, and jumping in area E (24 items) in the Gross Motor Function Measure (GMFM). Calculate the score according to the completion degree of each item (0-3 points) and get the total score of Zones D and E. The higher the score, the better the gross motor function.</li>
		<li>Calculate the efficacy rate using equations (1) and (2) and assess the clinical effectiveness of gross motor function interventions by measuring the difference in the scores from the GMFM-88E section before and after treatment. 
		Efficacy rate (%) = <img alt="Equation 1" src="/files/ftp_upload/66013/66013eq01.jpg" style="margin: auto;" />&#160; &#160;(1) 
		&#8203;Efficacy rate = significant effective rate + effective rate&#160; &#160;(2)
		<ol>
			<li>Consider the outcome to be significantly effective if the efficacy rate is &#62;50%.</li>
			<li>Consider the outcome to be effective if the efficacy rate is between 20% and 50%.</li>
			<li>Consider the outcome to be ineffective if the efficacy rate is &#60;20%.</li>
		</ol>
		</li>
	</ol>
	</li>
</ol>
4. Therapeutic method
NOTE: Explain the principles and objectives of the training program, as well as possible adverse effects and safety issues during the training process, to the guardians of the children.
<ol>
	<li>Randomly divide the children with SCP into four different groups: a conventional group, a rTMS group, an AOT group, and a combination intervention group according to the numerical table method (16 cases in each group in this study).</li>
	<li>Ensure that all the children receive conventional rehabilitation treatment, based on which they will be given different rehabilitation treatment measures. The conventional group receives no other rehabilitation treatment; the rTMS group receives rTMS; the AOT group receives AOT; and the study group receives rTMS combined with AOT.
	<ol>
		<li>Explain in detail to the families of the subject children the possibilities of their participation in training programs of conventional rehabilitation, rTMS, AOT, and combined interventions. Ensure that the researchers are blinded to the allocation of the subjects and are not involved in the assessment.</li>
		<li>According to the admission order of these children, generate a numerical list as a spreadsheet. Randomize into groups as follows: numbers 1, 5, 9... for the regular group; numbers 2, 6, 10&#8230; for the rTMS group; numbers 3, 7, 11&#8230; for the AOT group; and numbers 4, 8, 12&#8230; for the combined intervention group. To ensure privacy, use a curtain to provide each child with a separate space during each treatment session.</li>
	</ol>
	</li>
	<li>Conventional rehabilitation
	<ol>
		<li>Exercise therapy
		<ol>
			<li>Explain the principle and purpose of exercise therapy to the guardians of the children and notify them that the duration of treatment is 30 min.</li>
			<li>According to their muscle strength rating, instruct the children to perform muscle strength exercises for the training of hip abductor muscles, hip posterior extensor muscles, and ankle dorsal extensor muscles, 10x per set and three sets per day.</li>
			<li>According to their balance function level, instruct the children to conduct balance training such as standing without support, standing with feet together, and standing on one leg, with a duration of 10 min each time.</li>
			<li>According to their walking ability, instruct the children to carry out walking training such as handholding, independent walking, and crossing obstacles, with a duration of 10 min each time.</li>
		</ol>
		</li>
		<li>Hydrotherapy
		<ol>
			<li>Explain the principle, process, and purpose of hydrotherapy to guardians of the children and notify them that the duration of treatment is 20 min.</li>
			<li>When using the special hydrotherapy machine for children, adjust the water temperature to an appropriate temperature of 37-38 &#176;C.</li>
			<li>Ask the parents to help their children take off their clothes, put on waterproof swimming trunks and hydrotherapy collars, and then get them into the hydrotherapy machine.</li>
			<li>Click on the bubble bath button to start treatment and instruct the children to stand, turn around, and take steps alternately with both feet in the water.</li>
		</ol>
		</li>
		<li>Massage treatment
		<ol>
			<li>Have the children diagnosed first.</li>
			<li>Explain the effects of massage treatment to the guardians of the children and notify them that the duration of treatment is 30 min.</li>
			<li>Place the children in the prone position and apply alternating pinching and pushing techniques 5-10x along both sides of the coronary artery and the bladder meridian.</li>
			<li>Place the children in the prone position and press, using the end of the thumb, the acupuncture points of Futu, Liangqiu, Zusanli, Jiexi, Huantiao, Chengfu, and Wuizhong from the top down.</li>
			<li>Place the children in the supine or prone position and apply rhythmic lifting and pinching 10-20x with the thumb and other four fingers alternately on the quadriceps, hamstrings, and calf triceps muscle at the same time.</li>
		</ol>
		</li>
	</ol>
	</li>
	<li>rTMS 
	NOTE: The physical therapist engaged in performing rTMS first participated in the training arranged by the manufacturer. For the safety of the participants, the therapist or other trained medical professionals must supervise the entire treatment process and inform the guardians in advance that the pulse generated by rTMS may cause temporary and mild pain and slight twitching of the face and limbs when it hits the scalp.
	<ol>
		<li>rTMS patient preparation
		<ol>
			<li>At the first visit, let the physical therapist know about the basic information and medical history of the subject children.</li>
			<li>Explain the process of rTMS treatment and possible responses to the guardians of the children and notify them that the duration of treatment is approximately 30 min.</li>
			<li>Place the children in the supine or seated position, degrease their hands with medical alcohol, and choose a suitable positioning cap for each of them according to their head circumference. Place the naso-occipital line on the positioning cap on the median line of the participating children, and the crossing point of the naso-occipital line and the temporal-parietal line at the midpoint of the line between the eyebrow and the occipital posterior carina. 
			NOTE: The appropriate size should be selected according to their head circumferences.</li>
			<li>Affix the recording electrode to the abdominal muscle of the abductor pollicis brevis of the participating children, the reference electrode to the tendon of the abductor pollicis brevis, and the bottom electrode to the wrist.</li>
		</ol>
		</li>
		<li>rTMS operation preparation
		<ol>
			<li>Start the computer application on the rTMS instrument, input the basic information and diagnoses of the participating children, and determine the treatment plan.</li>
			<li>The stimulation coil is a circular air-cooled coil, the center of which coincides with the contralateral M1 area corresponding to the identified abductor pollicis brevis. Place the coil at 45&#176; to the scalp. 
			NOTE: The positioning cap was designed according to the electroencephalography (EEG) 10-20 electrode arrangement system, which could quickly locate the M1 region.</li>
			<li>Select a stimulation intensity of 30% and stimulate the M1 region corresponding to the contralateral abductor pollicis brevis muscle by manual monopulse. 
			NOTE: During the treatment, the participating children should hold their position to avoid deviation of the stimulation target.</li>
			<li>Observe the motor evoked potentials interface graph and gradually reduce the stimulation intensity. Define the RMT as the minimum stimulus intensity that will elicit this response if at least 5 out of 10 consecutive stimulations of the child&#39;s primary motor cortex (M1) induce a motor potential strength of more than 50 mV in the contralateral abductor hallucis brevis muscle (Figure 1A).</li>
			<li>Click on the confirm button, save the RMT record, and then enter the treatment parameter setting page.</li>
		</ol>
		</li>
		<li>rTMS treatment
		<ol>
			<li>Use the following settings to perform low-frequency stimulation on the M1 region of the undamaged cerebral cortex: stimulation frequency 1 Hz, stimulation intensity 80% RMT, stimulation number 10, stimulation time 10 s, the number of repetitions 80, and the total number of pulses 80025,26 (see Figure 1B).</li>
			<li>Use the following settings to perform high-frequency stimulation of the M1 region of the damaged cerebral cortex: stimulation frequency 5 Hz, stimulation intensity 100% RMT, stimulation number 15, stimulation time 3 s, repetition times 80, and the total number of pulses 1,20010(see Figure 1C).</li>
			<li>Observe the responses of the participating children. For example, if the children start crying due to scalp beating, have excessive facial twitching, or show signs of a seizure and other adverse reactions, stop the treatment immediately. 
			NOTE: For children with spastic diplegia/quadriplegia, high-frequency stimulation of the M1 region of the damaged cerebral cortex was performed alternately on both sides of the damaged brain. For those with spastic hemiplegia, the M1 region of the undamaged cerebral cortex was stimulated at a low frequency, while the damaged cerebral cortex of M1 area was stimulated at a high frequency.</li>
		</ol>
		</li>
	</ol>
	</li>
	<li>AOT 
	NOTE: AOT requires physical therapists to video subjects&#39; body movements in advance and supervise the safety and training accuracy of the whole treatment process.
	<ol>
		<li>Explain the principle, process, and precautions of AOT to the guardians of the children, and notify them that the duration is 30 min.</li>
		<li>Have two professional physiotherapists shoot videos of body movements from three different angles: front, side, and back, and design six body movements for the purpose of improving lower limb balance and walking function.
		<ol>
			<li>The first movement goes from sitting to standing: move the body forward from the upright sitting position by lifting the pelvis and extending the knee joint, gradually converting to the standing position, and then sit down. Perform this 3x consecutively (Figure 2A).</li>
			<li>The second movement is a standing exercise: move the body weight to the left or right as far as possible and then back to the neutral position. Perform it 3x in turn (Figure 2B).</li>
			<li>The third movement is also a standing exercise: move the body weight forward or backward as far as possible and then return to the neutral position. Perform it 3x in turn (Figure 2C).</li>
			<li>The fourth movement is also a standing exercise: rotate the body to the left or right as far as possible and then return to the neutral position. Perform it 3x in turn (Figure 2D).</li>
			<li>The fifth movement is a standing exercise: walk sideways to the left or right and then return to the neutral position. Perform it 3x in turn (Figure 2E).</li>
			<li>The sixth movement is a standing exercise: alternately step up or down a 10 cm high step with the left and right feet. Perform it 3x in turn (Figure 2F).</li>
		</ol>
		</li>
		<li>Get the children gathered in a quiet room and sitting 5 m away from an 86 inch TV in comfortable positions.</li>
		<li>Have the physiotherapist explain the body movements first so that the children can then focus on watching the video.</li>
		<li>After watching the video, ask the children to imitate these movements.</li>
	</ol>
	</li>
</ol>
5. Post treatment evaluation
NOTE: The pretreatment and 12 week post treatment evaluation for each patient would be completed by the same pediatric rehabilitation doctor.
<ol>
	<li>After 12 weeks of different rehabilitation measures for the four groups of children, have the same pediatric rehabilitation doctor re-evaluate the clinical efficacy of CSS, PBS, 10 MWS, GMFM, and gross motor function.</li>
	<li>Record the guardians&#39; satisfaction and feedback on the treatment plan, including the degree of enjoyment of the treatment and improvement in self-awareness, as well as their wishes and suggestions for continuing the treatment.</li>
</ol>
6. Statistical analysis
<ol>
	<li>Enter the demographics, CSS, PBS, 10 m walking speed (10MWS), GMFM, and effective rate (%) assessment data into the software for statistical analysis.</li>
	<li>Analyze the counting data using the &#967;2 Test or Fisher Probabilistic Precision method.</li>
	<li>Determine whether the data conform to a normal distribution and express normally distributed data as mean &#177; SD.
	<ol>
		<li>Use repetitive measurement deviation analysis for comparison among the four groups and perform repeated measures analysis of variance under the mixed model to verify whether the results and variation scores of each group are consistent with the approximately normal distribution.</li>
	</ol>
	</li>
	<li>Consider time as an intra-group factor and intervention an inter-group factor. If there is any interaction between these two factors, test the inter-group difference at each time point at a= 0.05. If there is no interaction effect, test the main effect. Consider differences to be statistically significant at P &#60; 0.05.</li>
</ol>

Combined Intervention Training for Children with Spastic Cerebral Palsy 

The authors have no conflicts of interest to declare.

For children with SCP, increased activity of &#947; and &#945; neurons leads toinhibition of corticospinal tract input, which results in increased muscle tension known as spasm. As limb spasms significantly affect the development of lower limb motor function of children with SCP, one of the crucial training goals is to reduce spasticity. Currently, stepwise treatment strategies are employed to alleviate spasticity, including rehabilitation nursing, physical therapy, orthopedic brace application, botulinum toxin injection...

Cerebral palsy1 (CP) is one of the most common disabling disorders in children and is a group of persistent syndromes caused by non-progressive brain damage in developing fetuses and infants, including central dyskinesia, abnormal posture, and limited mobility. Currently, there are approximately 17 million children worldwide affected by cerebral palsy2, with over 5 million cases in China. Among various forms of cerebral palsy, spastic cerebral palsy (SCP) accounts for roughly 80%3. Children with SCP suffer from brain damage resulting in muscle spasms, diminished sensory function, impaired muscle coordination, and decreased balance capabilities, all of which hinder independent walking and daily activities. Current rehabilitation measures for enhancing gross motor function in children with SCP encompass activities such as core stability training4, task-oriented training5, constraint-induced movement therapy6, and mirror visual feedback therapy7. These measures can improve clinical symptoms of children by regulating and reshaping the central nervous system from bottom to top by improving the functions of peripheral organs. 
Transcranial magnetic stimulation (TMS)8,9 is a painless, non-invasive, and safe therapeutic method. rTMS refers to the continuous release of stimuli at equal intervals after a single command, which is one of the regular repetitive stimulation patterns. Based on the principle of electromagnetic induction and electromagnetic conversion, it applies transient currents through stimulation coils to form a pulsed magnetic field to penetrate the skull, generate induction current to stimulate neurons and trigger a series of physiological and biochemical responses. rTMS has been applied to the monitoring, evaluation, and treatment of neurological diseases, providing a novel approach to exploring the structure and function of the brain10. Existing studies11,12 have shown that rTMS has varying therapeutic effects on limb spasms and motor function in children with CP. Moreover, the effect of rTMS treatment combined with other rehabilitation techniques is more noticeable. 
AOT is a rehabilitation method that utilizes the Mirror Neuron System (MNS) to establish motor learning and memory13,14. The essence of AOT is to make the observer carefully observe actions in the video and subsequently try their best to imitate what they observed. The observing process might trigger activation in the neural network known as MNS, akin to the activation that occurs when one is personally engaged in executing those actions15, which provides a neurophysiological basis for AOT. AOT has shown success in improving motor skills in patients with movement disorders, yielding positive outcomes in stroke recovery and rehabilitation of upper limb motor function in cerebral palsy patients16,17. 
Our previous studies have found that AOT based on the mirror neuron system could effectively improve the balance and walking ability of children with cerebral palsy18. In addition, studies19 have shown that rTMS can improve muscle spasticity, movement, and gait in children with SCP, but treatment standards of rTMS applied to children with cerebral palsy have not been unified, and it is an urgent problem to explore the influence of different parameters of rTMS on children with CP, to provide a personalized and precise treatment standard. We believe that combining rTMS with AOT has the potential to develop into a valuable physical therapy strategy for the neurological rehabilitation of cerebral palsy. Both rTMS and AOT stimulated the cerebral cortex in children with SCP20, thereby aiding gross motor function development. This study aimed to find out whether the combination of rTMS and AOT could achieve a greater synergistic effect than conventional treatment or rTMS or AOT alone.

<table><tbody><tr><td>K6 multimedia scene interactive training system</td><td>Hunan Le Jiekang technology Co., LTD</td><td></td><td>Program implementation</td></tr><tr><td>KLW-SLL type spa machine for children</td><td>Nanjing Kanglongwei Technology Industrial Co., LTD</td><td></td><td>Conventional therapy</td></tr><tr><td>Pulse magnetic field stimulator model YRD CCY-II</td><td>Shenzhen Yingzhi technology Co., LTD</td><td></td><td>Program implementation</td></tr><tr><td>SPSS26 software</td><td>IBM</td><td></td><td>Statistic analysis</td></tr></tbody></table>

repeated transcranial magnetic stimulation combined with action observation training in children with spastic cerebral palsy

This study presents the results of a randomized controlled trial utilizing a 2 x 2 factorial design, comparing the effects of repeated transcranial magnetic stimulation (rTMS) and action observation training (AOT) intervention methods on spasticity, balance function, and motor function in children with spastic cerebral palsy (SCP). The study aimed to investigate whether the combination of the two interventions produces greater improvement than either treatment alone or conventional treatment.
Subject children in this study, in accordance with the random number table, were randomly divided into four groups: conventional group, rTMS group, AOT group, and combined intervention group. All the children in the four groups received conventional rehabilitation treatment, on the basis of which they were given different therapeutic programs of rehabilitation measures. The conventional group had no other treatment while the rTMS group received rTMS, the AOT group received AOT and the combined intervention group was given a combined intervention of rTMS and AOT. They were trained five days per week for 12 weeks. Changes in scores of spasticity, balance function, walking ability, and gross motor function were assessed at the onset of the training program and upon completion of 12 weeks of treatment.
A total of 64 Children with SCP completed the study, and their results were analyzed. The total gross motor function efficiency of 87.50% in the experimental group was significantly higher than that of 25.00% in the conventional group, 62.50% in the rTMS group, and 68.75% in the AOT group. The preliminary results showed that combined intervention of rTMS and AOT could effectively improve the balance function and motor function of children, and the therapeutic effect of the combined intervention was better than that of conventional treatment, rTMS or AOT alone. Finally, clinical efficacy and optimal treatment parameters of the combined intervention were clarified to provide a clinical basis for therapists to conduct lower limb function rehabilitation for children with SCP.

This paper presents the results of 64 children with SCP (Supplementary Table S1 and Supplementary File 1), who were randomly divided into four groups according to the numerical table method and given different rehabilitation measures for 12 weeks. During the entire process, the participating children had no adverse reactions such as headaches, dizziness, and seizures.
The demographic data of the four groups of children are shown in Table 1. Be...

Author Spotlight: Repetitive Transcranial Magnetic Stimulation Combined with Movement Observation in Cerebral Palsy

Children with spastic cerebral palsy (SCP) have limb spasticity, movement disorders, and abnormal posture due to injury to the cerebral cortex motor area, resulting in inability to stand and walk normally. Therefore, alleviating limb spasticity and enhancing gross motor function in children with SCP have become important therapeutic goals.

Repeated Transcranial Magnetic Stimulation Combined with Action Observation Training in Children with Spastic Cerebral Palsy

This study presents the results of a randomized controlled trial utilizing a 2 x 2 factorial design, comparing the effects of repeated transcranial ...

repeated-transcranial-magnetic-stimulation-combined-with-action

Research

JoVE Journal

Medicine

980 Views.  Xiangya Boai Rehabilitation Hospital. Children with spastic cerebral palsy (SCP) have limb spasticity, movement disorders, and abnormal posture due to injury to the cerebral cortex motor area, resulting in inability to stand and walk normally. Therefore, alleviating limb spasticity and enhancing gross motor function in children with SCP have become important therapeutic goals. 

Video: Author Spotlight: Repetitive Transcranial Magnetic Stimulation Combined with Movement Observation in Cerebral Palsy

Corticospinal Excitability Modulation During Action Observation

This study used the transcranial magnetic stimulation/motor evoked potential (TMS/MEP) technique to pinpoint when the automatic tendency to mirror someone else's action becomes anticipatory simulation of a complementary act. TMS was delivered to the left primary motor cortex corresponding to the hand to induce the highest level of MEP activity from the abductor digiti minimi (ADM; the muscle serving little finger abduction) as well as the first dorsal interosseus (FDI; the muscle serving index finger flexion/extension) muscles. A neuronavigation system was used to maintain the position of the TMS coil, and electromyographic (EMG) activity was recorded from the right ADM and FDI muscles. Producing original data with regard to motor resonance, the combined TMS/MEP technique has taken research on the perception-action coupling mechanism a step further. Specifically, it has answered the questions of how and when observing another person's actions produces motor facilitation in an onlooker's corresponding muscles and in what way corticospinal excitability is modulated in social contexts.

Single-pulse transcranial magnetic stimulation over the primary motor cortex, neuronavigation, and registration of electromyographic activity of hand muscles were used in this study to explore corticospinal excitability while participants were observing action sequences.

This study used the transcranial magnetic stimulation/motor evoked potential (TMS/MEP) technique to pinpoint when the automatic tendency to mirror someone ...

Behavior

Utilizing Transcranial Magnetic Stimulation to Study the Human Neuromuscular System

Transcranial magnetic stimulation (TMS) has been in use for more than 20 years 1, and has grown exponentially in popularity over the past decade. While the use of TMS has expanded to the study of many systems and processes during this time, the original application and perhaps one of the most common uses of TMS involves studying the physiology, plasticity and function of the human neuromuscular system. Single pulse TMS applied to the motor cortex excites pyramidal neurons transsynaptically 2 (Figure 1) and results in a measurable electromyographic response that can be used to study and evaluate the integrity and excitability of the corticospinal tract in humans 3. Additionally, recent advances in magnetic stimulation now allows for partitioning of cortical versus spinal excitability 4,5. For example, paired-pulse TMS can be used to assess intracortical facilitatory and inhibitory properties by combining a conditioning stimulus and a test stimulus at different interstimulus intervals 3,4,6-8. In this video article we will demonstrate the methodological and technical aspects of these techniques. Specifically, we will demonstrate single-pulse and paired-pulse TMS techniques as applied to the flexor carpi radialis (FCR) muscle as well as the erector spinae (ES) musculature. Our laboratory studies the FCR muscle as it is of interest to our research on the effects of wrist-hand cast immobilization on reduced muscle performance6,9, and we study the ES muscles due to these muscles clinical relevance as it relates to low back pain8. With this stated, we should note that TMS has been used to study many muscles of the hand, arm and legs, and should iterate that our demonstrations in the FCR and ES muscle groups are only selected examples of TMS being used to study the human neuromuscular system.

Transcranial magnetic stimulation (TMS) is a non-invasive tool to gain insight on the physiology and function of the human nervous system. Here, we present our TMS techniques to study cortical excitability of the upper limb and lumbar musculature.

Transcranial magnetic stimulation (TMS) has been in use for more than 20 years 1, and has grown exponentially in popularity over the past decade.  While ...

Eye Tracking Young Children with Autism

The rise of accessible commercial eye-tracking systems has fueled a rapid increase in their use in psychological and psychiatric research. By providing a direct, detailed and objective measure of gaze behavior, eye-tracking has become a valuable tool for examining abnormal perceptual strategies in clinical populations and has been used to identify disorder-specific characteristics1, promote early identification2, and inform treatment3. In particular, investigators of autism spectrum disorders (ASD) have benefited from integrating eye-tracking into their research paradigms4-7. Eye-tracking has largely been used in these studies to reveal mechanisms underlying impaired task performance8 and abnormal brain functioning9, particularly during the processing of social information1,10-11. While older children and adults with ASD comprise the preponderance of research in this area, eye-tracking may be especially useful for studying young children with the disorder as it offers a non-invasive tool for assessing and quantifying early-emerging developmental abnormalities2,12-13. Implementing eye-tracking with young children with ASD, however, is associated with a number of unique challenges, including issues with compliant behavior resulting from specific task demands and disorder-related psychosocial considerations. In this protocol, we detail methodological considerations for optimizing research design, data acquisition and psychometric analysis while eye-tracking young children with ASD. The provided recommendations are also designed to be more broadly applicable for eye-tracking children with other developmental disabilities. By offering guidelines for best practices in these areas based upon lessons derived from our own work, we hope to help other investigators make sound research design and analysis choices while avoiding common pitfalls that can compromise data acquisition while eye-tracking young children with ASD or other developmental difficulties.

Eye tracking has long been used to study gaze patterns in typically-developing individuals, but recent technological advancements have made its use with clinical populations, including autism, more feasible. While eye-tracking young children with autism can offer insight into early symptom manifestations, it involves methodological challenges. Suggestions for best practices are provided.

The rise of accessible commercial eye-tracking systems has fueled a rapid increase in their use in psychological and psychiatric research. By providing a ...

A Murine Model of Muscle Training by Neuromuscular Electrical Stimulation

Neuromuscular electrical stimulation (NMES) is a common clinical modality that is widely used to restore1, maintain2 or enhance3-5 muscle functional capacity. Transcutaneous surface stimulation of skeletal muscle involves a current flow between a cathode and an anode, thereby inducing excitement of the motor unit and the surrounding muscle fibers. 
NMES is an attractive modality to evaluate skeletal muscle adaptive responses for several reasons. First, it provides a reproducible experimental model in which physiological adaptations, such as myofiber hypertophy and muscle strengthening6, angiogenesis7-9, growth factor secretion9-11, and muscle precursor cell activation12 are well documented. Such physiological responses may be carefully titrated using different parameters of stimulation (for Cochrane review, see 13). In addition, NMES recruits motor units non-selectively, and in a spatially fixed and temporally synchronous manner14, offering the advantage of exerting a treatment effect on all fibers, regardless of fiber type. Although there are specified contraindications to NMES in clinical populations, including peripheral venous disorders or malignancy, for example, NMES is safe and feasible, even for those who are ill and/or bedridden and for populations in which rigorous exercise may be challenging. 
Here, we demonstrate the protocol for adapting commercially available electrodes and performing a NMES protocol using a murine model. This animal model has the advantage of utilizing a clinically available device and providing instant feedback regarding positioning of the electrode to elicit the desired muscle contractile effect. For the purpose of this manuscript, we will describe the protocol for muscle stimulation of the anterior compartment muscles of a mouse hindlimb.

A murine model of neuromuscular electrical stimulation (NMES), a safe and inexpensive clinical modality, to the anterior compartment muscles is described. This model has the advantage of modifying a readily available clinical device for the purpose of eliciting targeted and specific muscle contractions in mice.

Neuromuscular electrical stimulation (NMES) is a common clinical modality that is widely used to restore1, maintain2 or enhance3-5 muscle functional ...

Effects of Transcranial Alternating Current Stimulation on the Primary Motor Cortex by Online Combined Approach with Transcranial Magnetic Stimulation

Transcranial Alternating Current Stimulation (tACS) is a neuromodulatory technique able to act through sinusoidal electrical waveforms in a specific frequency and in turn modulate ongoing cortical oscillatory activity. This neurotool allows the establishment of a causal link between endogenous oscillatory activity and behavior. Most of the tACS studies have shown online effects of tACS. However, little is known about the underlying action mechanisms of this technique because of the AC-induced artifacts on Electroencephalography (EEG) signals. Here we show a unique approach to investigate online physiological frequency-specific effects of tACS of the primary motor cortex (M1) by using single pulse Transcranial Magnetic Stimulation (TMS) to probe cortical excitability changes. In our setup, the TMS coil is placed over the tACS electrode while Motor Evoked Potentials (MEPs) are collected to test the effects of the ongoing M1-tACS. So far, this approach has mainly been used to study the visual and motor systems. However, the current tACS-TMS setup can pave the way for future investigations of cognitive functions. Therefore, we provide a step-by-step manual and video guidelines for the procedure.

Transcranial Alternating Current Stimulation (tACS) allows the modulation of cortical excitability in a frequency-specific fashion. Here we show a unique approach which combines online tACS with single pulse Transcranial Magnetic Stimulation (TMS) in order to "probe" cortical excitability by means of Motor Evoked Potentials.

Transcranial Alternating Current Stimulation (tACS) is a neuromodulatory technique able to act through sinusoidal electrical waveforms in a specific ...

Neuroscience

Online Transcranial Magnetic Stimulation Protocol for Measuring Cortical Physiology Associated with Response Inhibition

We describe the development of a reproducible, child-friendly motor response inhibition task suitable for online Transcranial Magnetic Stimulation (TMS) characterization of primary motor cortex (M1) excitability and inhibition. Motor response inhibition prevents unwanted actions and is abnormal in several neuropsychiatric conditions. TMS is a non-invasive technology that can quantify M1 excitability and inhibition using single- and paired-pulse protocols and can be precisely timed to study cortical physiology with high temporal resolution. We modified the original Slater-Hammel (S-H) stop signal task to create a &#34;racecar&#34; version with TMS pulses time-locked to intra-trial events. This task is self-paced, with each trial initiating after a button push to move the racecar towards the 800 ms target. GO trials require a finger-lift to stop the racecar just before this target. Interspersed randomly are STOP trials (25%) during which the dynamically adjusted stop signal prompts subjects to prevent finger-lift. For GO trials, TMS pulses were delivered at 650 ms after trial onset; whereas, for STOP trials, the TMS pulses occurred 150 ms after the stop signal. The timings of the TMS pulses were decided based on electroencephalography (EEG) studies showing event-related changes in these time ranges during stop signal tasks. This task was studied in 3 blocks at two study sites (n=38) and we recorded behavioral performance and event-related motor-evoked potentials (MEP). Regression modelling was used to analyze MEP amplitudes using age as a covariate with multiple independent variables (sex, study site, block, TMS pulse condition [single- vs. paired-pulse], trial condition [GO, successful STOP, failed STOP]). The analysis showed that TMS pulse condition (p&#60;0.0001) and its interaction with trial condition (p=0.009) were significant. Future applications for this online S-H/TMS paradigm include the addition of simultaneous EEG acquisition to measure TMS-evoked EEG potentials. A potential limitation is that in children, the TMS pulse sound could&#160;affect behavioral task performance.

We describe an experimental procedure to quantify excitability and inhibition of primary motor cortex during a motor response inhibition task by using Transcranial Magnetic Stimulation throughout the course of a Stop Signal Task.

We describe the development of a reproducible, child-friendly motor response inhibition task suitable for online Transcranial Magnetic Stimulation (TMS) ...

The Combined Use of Transcranial Direct Current Stimulation and Robotic Therapy for the Upper Limb

Neurologic disorders such as stroke and cerebral palsy are leading causes of long-term disability and can lead to severe incapacity and restriction of daily activities due to lower and upper limb impairments. Intensive physical and occupational therapy are still considered main treatments, but new adjunct therapies to standard rehabilitation that may optimize functional outcomes are being studied.
Transcranial direct current stimulation (tDCS) is a noninvasive brain stimulation technique that polarizes underlying brain regions through the application of weak direct currents through electrodes on the scalp, modulating cortical excitability. Increased interest in this technique can be attributed to its low cost, ease of use, and effects on human neural plasticity. Recent research has been performed to determine the clinical potential of tDCS in diverse conditions such as depression, Parkinson&#39;s disease, and motor rehabilitation after stroke. tDCS helps enhance brain plasticity and seems to be a promising technique in rehabilitation programs.
A number of robotic devices have been developed to assist in the rehabilitation of upper limb function after stroke. The rehabilitation of motor deficits is often a long process requiring multidisciplinary approaches for a patient to achieve maximum independence. These devices do not intend to replace manual rehabilitation therapy; instead, they were designed as an additional tool to rehabilitation programs, allowing immediate perception of results and tracking of improvements, thus helping patients to stay motivated.
Both tDSC and robot-assisted therapy are promising add-ons to stroke rehabilitation and target the modulation of brain plasticity, with several reports describing their use to be associated with conventional therapy and the improvement of therapeutic outcomes. However, more recently, some small clinical trials have been developed that describe the associated use of tDCS and robot-assisted therapy in stroke rehabilitation. In this article, we describe the combined methods used in our institute for improving motor performance after stroke.

The combined use of transcranial direct current stimulation and robotic therapy as an add-on for conventional rehabilitation therapy may result in improved therapeutic outcomes due to modulation of brain plasticity. In this article, we describe the combined methods used in our institute for improving motor performance after stroke.

Neurologic disorders such as stroke and cerebral palsy are leading causes of long-term disability and can lead to severe incapacity and restriction of ...

Non-Invasive Modulation and Robotic Mapping of Motor Cortex in the Developing Brain

Mapping the motor cortex with transcranial magnetic stimulation (TMS) has potential to interrogate motor cortex physiology and plasticity but carries unique challenges in children. Similarly, transcranial direct current stimulation (tDCS) can improve motor learning in adults but has only recently been applied to children. The use of tDCS and emerging techniques like high&#8211;definition tDCS (HD-tDCS) require special methodological considerations in the developing brain. Robotic TMS motor mapping may confer unique advantages for mapping, particularly in the developing brain. Here, we aim to provide a practical, standardized approach for two integrated methods capable of simultaneously exploring motor cortex modulation and motor maps in children. First, we describe a protocol for robotic TMS motor mapping. Individualized, MRI-navigated 12x12 grids centered on the motor cortex guide a robot to administer single-pulse TMS. Mean motor evoked potential (MEP) amplitudes per grid point are used to generate 3D motor maps of individual hand muscles with outcomes including map area, volume, and center of gravity. Tools to measure safety and tolerability of both methods are also included. Second, we describe the application of both tDCS and HD-tDCS to modulate the motor cortex and motor learning. An experimental training paradigm and sample results are described. These methods will advance the application of non-invasive brain stimulation in children.

We demonstrate protocols for the modulation (tDCS, HD-tDCS) and mapping (robotic TMS) of the motor cortex in children.

Mapping the motor cortex with transcranial magnetic stimulation (TMS) has potential to interrogate motor cortex physiology and plasticity but carries ...

Combined Peripheral Nerve Stimulation and Controllable Pulse Parameter TMS

Combined Peripheral Nerve Stimulation and Controllable Pulse Parameter Transcranial Magnetic Stimulation to Probe Sensorimotor Control and Learning

Skilled motor ability depends on efficiently integrating sensory afference into the appropriate motor commands. Afferent inhibition provides a valuable tool to probe the procedural and declarative influence over sensorimotor integration during skilled motor actions. This manuscript describes the methodology and contributions of short-latency afferent inhibition (SAI) for understanding sensorimotor integration. SAI quantifies the effect of a convergent afferent volley on the corticospinal motor output evoked by transcranial magnetic stimulation (TMS). The afferent volley is triggered by the electrical stimulation of a peripheral nerve. The TMS stimulus is delivered to a location over the primary motor cortex that elicits a reliable motor-evoked response in a muscle served by that afferent nerve. The extent of inhibition in the motor-evoked response reflects the magnitude of the afferent volley converging on the motor cortex and involves central GABAergic and cholinergic contributions. The cholinergic involvement in SAI makes SAI a possible marker of declarative-procedural interactions in sensorimotor performance and learning. More recently, studies have begun manipulating the TMS current direction in SAI to tease apart the functional significance of distinct sensorimotor circuits in the primary motor cortex for skilled motor actions. The ability to control additional pulse parameters (e.g., the pulse width) with state-of-the-art controllable pulse parameter TMS (cTMS) has enhanced the selectivity of the sensorimotor circuits probed by the TMS stimulus and provided an opportunity to create more refined models of sensorimotor control and learning. Therefore, the current manuscript focuses on SAI assessment using cTMS. However, the principles outlined here also apply to SAI assessed using conventional fixed pulse width TMS stimulators and other forms of afferent inhibition, such as long-latency afferent inhibition (LAI).

Author Spotlight: Combined Peripheral Nerve Stimulation and Controllable Pulse Parameter Transcranial Magnetic Stimulation to Probe Sensorimotor Control and Learning  

Short-latency afferent inhibition (SAI) is a transcranial magnetic stimulation protocol to probe sensorimotor integration. This article describes how SAI can be used to study the convergent sensorimotor loops in the motor cortex during sensorimotor behavior.

Skilled motor ability depends on efficiently integrating sensory afference into the appropriate motor commands. Afferent inhibition provides a valuable ...

Using TMS to Measure Motor Excitability During Action Observation

Source: Laboratories of Jonas T. Kaplan and Sarah I. Gimbel&#8212;University of Southern California
Transcranial Magnetic Stimulation (TMS) is a non-invasive brain stimulation technique that involves passing current through an insulated coil placed against the scalp. A brief magnetic field is created by current in the coil, and because of the physical process of induction, this leads to a current in the nearby neural tissue. Depending on the duration, frequency, and magnitude of these magnetic pulses, the underlying neural circuitry can be affected in many different ways. Here, we demonstrate the technique of single-pulse TMS, in which one brief magnetic pulse is used to stimulate the neocortex.
One observable effect of TMS is that it can produce muscle twitches when applied over the motor cortex. Due to the somatotopic organization of the motor cortex, different muscles can be targeted depending on the precise placement of the coil. The electrical signals that cause these muscle twitches, called motor evoked potentials, or MEPs, can be recorded and quantified by electrodes placed on the skin over the targeted muscle. The amplitude of MEPs can be interpreted to reflect the underlying excitability of the motor cortex; for example, when the motor cortex is activated, observed MEPs are larger. 
In this experiment, based on a study originally performed by Fadiga and colleagues1 and since replicated by many others,2 we use single-pulse TMS to test the excitability of motor cortex during action observation. It is known that motor cortex can be activated not only when we move, but when we watch others perform movements. A common interpretation of this phenomenon is that it reflects a simulation process that may play a role in the understanding of others' actions. Here we will record MEPs evoked by TMS over the primary motor cortex while subjects observe the movements of others compared with control stimuli.