This research was supported by a grant from the National Health Commission Science and Technology Plan Project, funded by the Medical and Health Science and Technology Development Research Center of the National Health Commission (grant number: HDSL202001051).

Prior to implementation, the Institutional Review Board of The Northern Jiangsu People&#39;s Hospital thoroughly assessed and granted approval for all procedures detailed in the subsequent protocol. In this study, patients are provided with comprehensive explanations of the processes involved, and their informed consent is duly obtained before employing electrophysiological technology for diagnostic and therapeutic purposes. The details of the reagents and equipment used are listed in the Table of Materials.
1. Patient selection
<ol>
	<li>Set the following inclusion criteria
	<ol>
		<li>Based on the established reference standard7 for varicocele using color Doppler flow imaging (CFDI), identify clinical varicocele by the presence of at least three spermatic veins within the spermatic venous plexus during a relaxed state. Confirm that one of these veins has an internal diameter exceeding 2.2 mm or shows a significant increase in diameter when abdominal pressure is applied.
		<ol>
			<li>Assess evident reflux of venous blood flow following the Valsalva test as another indicative factor for varicocele10. Look for symptoms related to scrotal pain.</li>
		</ol>
		</li>
		<li>Ensure the subject is aged 18 to 50 years old.</li>
		<li>Confirm that the subject has not taken any medication for varicocele treatment in the last month.</li>
	</ol>
	</li>
	<li>Set the following exclusion criteria
	<ol>
		<li>Exclude secondary varicocele.</li>
		<li>Exclude individuals with orchitis, epididymitis, or syringomyelia11.</li>
		<li>Exclude individuals with metallic medical stimulators (e.g., pacemakers) in the body.</li>
		<li>Exclude those who are allergic to skin electrode materials.</li>
		<li>Exclude those with broken skin at the treatment site.</li>
	</ol>
	</li>
</ol>
2. Diagnosis and treatment process
NOTE: Anesthetization is not required for this procedure.
<ol>
	<li>Pre-examination preparation
	<ol>
		<li>Have the patient sit still or lie flat to rest for 15 min.</li>
		<li>Ask the patient to enter the examination compartment, remove all clothing, and face the scanner (Figure 1).</li>
		<li>Ask the patient to follow the system voice instructions for movements. Click on Freeze (Figure 2) on the operation side to save the image (performed by the doctor). 
		NOTE: The system utilizes infrared thermal imaging combined with a recorder. Instructions include raising arms to capture armpits or turning backward to capture the back. No questions are asked.</li>
	</ol>
	</li>
	<li>Finding the abnormal temperature area
	<ol>
		<li>Move the mouse to the testicles in the patient&#39;s action screen. Observe the abnormal body temperature region. The normal temperature region is displayed in yellow, the high-temperature region in red, and the low-temperature region in green (Figure 3). 
		NOTE: Abnormal body temperature areas in patients with varicocele are often found in the inguinal area and the testis on the affected side.</li>
		<li>Subtract the temperature of the healthy testis from the temperature of the affected testis to obtain the bilateral scrotal temperature difference.</li>
	</ol>
	</li>
</ol>
3. Concluding the treatment
<ol>
	<li>Apply electrode pads to the patient&#39;s abdomen and bilateral inguinal regions.</li>
	<li>Adjust the current intensity and pulse width (4 Hz, 400 &#181;s) on the electrode pads to levels acceptable to the patient.</li>
	<li>Record the current intensity and pulse width at which the area of temperature abnormality on the scanner returns to normal.</li>
	<li>Locate the treatment protocol in the system that corresponds to the recorded current intensity and pulse width.</li>
	<li>Input the treatment protocol into the removable low-frequency neuromuscular therapy device. Guide the patient through the treatment, selecting appropriate parameters within a frequency range of 1-400 Hz and a pulse width of 50-1000 &#181;s.</li>
</ol>
4. Patient follow-up steps
<ol>
	<li>Arrange for the patient to return for follow-up visits to monitor progress and assess the effectiveness of the treatment.</li>
	<li>Instruct the patient to report any changes in symptoms, including improvements or new discomfort, during follow-up appointments.</li>
	<li>Perform follow-up imaging to evaluate the status of the varicocele and ensure the treatment has had the desired effect.</li>
	<li>Based on the follow-up imaging and symptom reports, adjust the treatment plan as needed to optimize outcomes.</li>
	<li>Review the patient&#39;s treatment progress and document all findings and changes in their medical record.</li>
	<li>Offer guidance on managing symptoms, lifestyle changes, and any additional treatments or therapies that may be required.</li>
	<li>Evaluate the patient for any side effects or complications resulting from the treatment and address them promptly.</li>
</ol>

Electrical Stimulation Therapy: Non-Surgical Remedy for Varicocele-Induced Pain

<ol>
	<li>Bellastella, G., Carotenuto, R., Caiazzo, F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Varicocele:+An+endocrinological+perspective.">Varicocele: An endocrinological perspective.</a> Front Reprod Health. 4, 863695 (2022).</li><li>Bozhedomov, V. A., Lipatova, N. A., Rokhlikov, I. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Male+fertility+and+varicocoele:+Role+of+immune+factors.">Male fertility and varicocoele: Role of immune factors.</a> Andrology. 2 (1), 51-58 (2014).</li><li>Bonyadi, M. R., Madaen, S. K., Saghafi, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+varicocelectomy+on+anti-sperm+antibody+in+patients+with+varicocele.">Effects of varicocelectomy on anti-sperm antibody in patients with varicocele.</a> J Reprod Infertil. 14 (2), 73-78 (2013).</li><li>Finelli, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+silico+sperm+proteome+analysis+to+investigate+DNA+repair+mechanisms+in+varicocele+patients.">In silico sperm proteome analysis to investigate DNA repair mechanisms in varicocele patients.</a> Front Endocrinol (Lausanne). 12, 757592 (2021).</li><li>Garolla, A., Torino, M., Miola, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Twenty-four-hour+monitoring+of+scrotal+temperature+in+obese+men+and+men+with+a+varicocele+as+a+mirror+of+spermatogenic+function.">Twenty-four-hour monitoring of scrotal temperature in obese men and men with a varicocele as a mirror of spermatogenic function.</a> Hum Reprod. 30 (5), 1006-1013 (2015).</li><li>Gomaa, M. D., Motawaa, M. A., Al-Nashar, A. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Impact+of+subinguinal+varicocelectomy+on+serum+testosterone+to+estradiol+ratio+in+male+patients+with+infertility.">Impact of subinguinal varicocelectomy on serum testosterone to estradiol ratio in male patients with infertility.</a> Urology. 117, 70-77 (2018).</li><li>Goulis, D., Mintziori, G., Koliakos, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Inhibin+B+and+anti-M&#252;llerian+hormone+in+spermatic+vein+of+subfertile+men+with+varicocele.">Inhibin B and anti-M&#252;llerian hormone in spermatic vein of subfertile men with varicocele.</a> Reprod Sci. 18 (6), 551-555 (2011).</li><li>Jin, G., Liu, J., Qin, Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Increased+Level+of+C-kit+in+semen+of+infertile+patients+with+varicocele.">Increased Level of C-kit in semen of infertile patients with varicocele.</a> Urol J. 14 (2), 3023-3027 (2017).</li><li>Kadioglu, T. C., Aliyev, E., Celtik, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microscopic+varicocelectomy+significantly+decreases+the+sperm+DNA+fragmentation+index+in+patients+with+infertility.">Microscopic varicocelectomy significantly decreases the sperm DNA fragmentation index in patients with infertility.</a> Biomed Res Int. 2014, 695713 (2014).</li><li>Lorenc, T., Krupniewski, L., Palczewski, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Warto&#347;&#263;+ultrasonografii+w+diagnostyce+&#380;ylak&#243;w+powr&#243;zka+nasiennego.">Warto&#347;&#263; ultrasonografii w diagnostyce &#380;ylak&#243;w powr&#243;zka nasiennego.</a> J Ultrasonography. 16 (67), 359-370 (2016).</li><li>Kummari, S., Das, S., Mahajan, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Role+of+high-resolution+ultrasonography+with+colour+and+duplex+doppler+in+the+evaluation+of+acute+scrotal+diseases.">Role of high-resolution ultrasonography with colour and duplex doppler in the evaluation of acute scrotal diseases.</a> Cureus. 15 (11), e49231 (2023).</li><li>Pogoreli&#263;, Z., Gaberc, T., Juki&#263;, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+effect+of+subcutaneous+and+intraperitoneal+instillation+of+local+anesthetics+on+postoperative+pain+after+laparoscopic+varicocelectomy:+A+randomized+controlled+trial.">The effect of subcutaneous and intraperitoneal instillation of local anesthetics on postoperative pain after laparoscopic varicocelectomy: A randomized controlled trial.</a> Children (Basel). 8 (11), 1051 (2021).</li><li>Kilin&#231;, F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experimental+varicocele+induces+hypoxia-inducible+factor-1alpha,+vascular+endothelial+growth+factor+expression+and+angiogenesis+in+the+rat+testis.">Experimental varicocele induces hypoxia-inducible factor-1alpha, vascular endothelial growth factor expression and angiogenesis in the rat testis.</a> J Urol. 172 (3), 1188-1191 (2004).</li><li>Krzy&#347;ciak, W., K&#243;zka, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Generation+of+reactive+oxygen+species+by+a+sufficient,+insufficient+and+varicose+vein+wall.">Generation of reactive oxygen species by a sufficient, insufficient and varicose vein wall.</a> Acta Biochim Pol. 58 (1), 89-94 (2011).</li><li>Tian, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+varicocelectomy+on+serum+FSH+and+LH+levels+for+patients+with+varicocele:+a+systematic+review+and+meta-analysis.">Effect of varicocelectomy on serum FSH and LH levels for patients with varicocele: a systematic review and meta-analysis.</a> Indian J Surg. 80 (3), 233-238 (2018).</li><li>Paick, S., Choi, W. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Varicocele+and+testicular+pain:+A+Review.">Varicocele and testicular pain: A Review.</a> World J Mens Health. 37 (1), 4-11 (2019).</li></ol>

The authors have no conflicts of interest to disclose.

The etiology of testicular pain in varicocele remains elusive, with potential mechanisms including increased testicular temperature, oxidative stress, testicular hypoxic injury, endocrine factors, and the involvement of renal/adrenal metabolic toxicity. When alternative causes of scrotal pain are excluded, and conservative treatment proves ineffective, surgical intervention becomes a crucial therapeutic approach for patients suffering from painful varicocele. Surgical techniques include retroperitoneal or inguinal approa...

Varicocele is a prevalent vascular abnormality affecting the male reproductive system, characterized by the enlargement, elongation, and tortuosity of the spermatic cord&#39;s venous plexus. It often leads to scrotal pain, discomfort, and progressive testicular hypogonadism, and is a major contributing factor to male infertility. Epidemiological studies have shown that varicocele affects approximately 10% to 15% of adult males. Among infertile men, the prevalence of varicocele can reach 40%, and scrotal pain occurs in 2% to 10% of cases1.
Varicose veins commonly occur on the left side of the spermatic cord, which can be attributed to two primary factors. Firstly, the left spermatic vein is anatomically longer than the right spermatic vein. Secondly, the right spermatic vein connects to the inferior vena cava, experiencing lower pressure, whereas the left spermatic vein joins the left renal vein at a right angle, resulting in higher pressure2. Increased venous pressure in the left renal vein, situated between the abdominal aorta and the superior mesenteric artery, leads to elevated pressure within the corresponding spermatic vein3.
The exact mechanism underlying scrotal pain in varicocele remains unclear. Potential contributing factors include elevated testicular temperature, oxidative stress, testicular hypoxic injury, endocrine dysregulation, and the influence of renal/adrenal metabolic toxins. These factors stimulate receptors, triggering the generation of action potentials that propagate through neural pathways within the spinal cord, ultimately transmitting electrical signals to the brain via the thalamic tracts located on the medial and posterior aspects of the spinal cord, resulting in pain perception4.
Clinical treatments for scrotal pain associated with varicocele encompass general measures, medication, and surgical interventions. General treatment involves lifestyle and dietary adjustments, which can provide some degree of symptom reduction. Pharmacological approaches often include the administration of hepatic saponins, such as Aescuven Forte, which exhibit anti-inflammatory and anti-exudative properties and help maintain the structural integrity of venous walls, particularly collagen fibers5. Treatment with hepatic saponins, such as Aescuven Forte, gradually restores the elasticity and contractile function of venous walls, thereby increasing venous blood reflux rate, reducing venous pressure, and alleviating symptoms like scrotal discomfort. Flavonoids and non-steroidal anti-inflammatory drugs are other commonly employed therapeutic agents that offer some efficacy in improving scrotal pain symptoms. Although physical cooling and scrotal rest have been utilized for varicocele-associated scrotal pain, their usage is limited due to decreased patient acceptance6.
Surgical interventions, such as open surgery, laparoscopic surgery, microscopic surgery, and interventional surgery, are commonly selected for patients with varicocele who experience more pronounced scrotal pain symptoms or infertility. Surgical treatment is currently regarded as the most effective approach, achieving up to an 80% success rate in relieving pain symptoms. However, it is important to acknowledge potential postoperative complications, including bleeding, wound infection, testicular sheath effusion, and testicular atrophy. Regardless of the surgical method chosen, the recurrence rate of varicocele ranges from 1.9% to 17.2%7.
Transcutaneous electrical nerve stimulation (TENS) is an extensively employed non-invasive physical therapy that applies electrical stimulation to the skin&#39;s surface, leading to pain relief and enhanced nerve function. By transmitting electrical currents through electrodes into nerve tissue, TENS influences nerve activity and finds widespread applications, including: (1) Pain relief: TENS effectively alleviates various types of pain, including muscle pain, neuralgia, and joint pain. The stimulation of nerve endings through TENS promotes the secretion of natural pain-relieving substances, such as endorphins, thereby reducing pain; (2) Rehabilitation training: TENS serves as a valuable tool in rehabilitation training, aiding in the restoration of impaired muscle and nerve function. For instance, after a sports injury, TENS can be used to alleviate pain and facilitate the recovery process; (3) Neuromodulation: TENS is also utilized for neuromodulation purposes, such as managing symptoms associated with urinary incontinence and constipation8.
The diverse therapeutic potential of transcutaneous electrical nerve stimulation (TENS) in pain management, rehabilitation, and neuromodulation highlights its efficacy and applicability. Through the stimulation of nerve endings, TENS promotes desirable neuromuscular responses, effectively ameliorating associated symptoms. Notably, TENS has demonstrated favorable efficacy in addressing male conditions such as erectile dysfunction and premature ejaculation. Patients readily embrace TENS due to its advantageous features of safety, reliability, and affordability. Furthermore, TENS treatment for venous vascular diseases yields beneficial outcomes, including pain relief, enhanced blood flow, and expedited wound healing9.
This study utilizes electrophysiological therapy-related technology to examine the effectiveness of transcutaneous neuromuscular electrical stimulation in alleviating scrotal pain associated with varicocele. The findings of this investigation have the potential to offer a valuable alternative treatment approach for individuals experiencing varicocele-related scrotal pain.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Low frequency neuromuscular therapy device</td>
			<td>Foshan Shanshan Datang Medical Technology Company</td>
			<td>BioStim pro</td>
			<td>Detachable and portable therapeutic instruments</td>
		</tr>
		<tr>
			<td>Medical infrared thermal imager</td>
			<td>Foshan Shanshan Datang Medical Technology Company</td>
			<td>PRISM 640A, PRISM 384A</td>
			<td>Instrument for infrared thermal imaging scanning of the human body</td>
		</tr>
		<tr>
			<td>Medical infrared thermal imaging system</td>
			<td>Foshan Shanshan Datang Medical Technology Company</td>
			<td>PRISM X 1.0.3</td>
			<td>Medical infrared thermal imager supporting computer system</td>
		</tr>
		<tr>
			<td>Surface electrodes for physical therapy</td>
			<td>Foshan Shanshan Datang Medical Technology Company</td>
			<td>JB50100, E6596, B50180</td>
			<td>Electrode plate</td>
		</tr>
	</tbody>
</table>

transcutaneous neuromuscular electrical stimulation for treating varicocele-induced scrotal pain

Varicocele is a prevalent vascular disorder affecting the male reproductive system, leading to scrotal pain and testicular dysfunction. Epidemiological studies have shown that varicocele occurs in approximately 10% to 15% of adult males, while scrotal pain affects 2% to 10% of the population. Currently, clinical treatment options for varicocele-induced scrotal pain include general therapy, medication, and surgery. Among these, surgical intervention is considered the most effective method, boasting a success rate of 80%. However, it carries risks such as postoperative bleeding, infection, and recurrence, making it less desirable for some patients. In recent years, transcutaneous neuromuscular electrical stimulation has gained wide acceptance for treating various andrological conditions, including erectile dysfunction and premature ejaculation, yielding positive outcomes. This non-invasive technique offers a promising alternative for managing varicocele-induced scrotal pain, potentially reducing the need for surgical intervention and its associated risks. Its growing popularity underscores the need for further research and clinical trials to validate its efficacy and safety in treating this condition.

The current protocol outlines the use of transcutaneous neuromuscular electrical stimulation for treating varicocele-induced scrotal pain. The therapeutic equipment used by the patients is displayed in Figure 4. Eventually, 38 patients completed the treatment, and the following results were obtained after performing a normality test on the data (Table 1). The mean Visual Analog Scale (VAS) score12 of the patients before treatment was 3.00 (3.00, 4.00)...

Author Spotlight: Advancing Varicocele Treatment with Neuromuscular Electrical Stimulation

This protocol outlines the use of transcutaneous neuromuscular electrical stimulation for treating varicocele-induced scrotal pain. It compares visual analog scale (VAS) scores and imaging changes before and after treatment to assess effectiveness. Results indicate that patients experienced improved scrotal pain symptoms following the treatment.

Transcutaneous Neuromuscular Electrical Stimulation for Treating Varicocele-Induced Scrotal Pain

Varicocele is a prevalent vascular disorder affecting the male reproductive system, leading to scrotal pain and testicular dysfunction. Epidemiological ...

transcutaneous-neuromuscular-electrical-stimulation-for-treating

Research

JoVE Journal

Medicine

588 Views.  Northern Jiangsu People's Hospital of Jiangsu Province. This protocol outlines the use of transcutaneous neuromuscular electrical stimulation for treating varicocele-induced scrotal pain. It compares visual analog scale (VAS) scores and imaging changes before and after treatment to assess effectiveness. Results indicate that patients experienced improved scrotal pain symptoms following the treatment.

Video: Author Spotlight: Advancing Varicocele Treatment with Neuromuscular Electrical Stimulation

Programmed Electrical Stimulation in Mice

Genetically-modified mice have emerged as a preferable animal model to study the molecular mechanisms underlying conduction abnormalities, atrial and ventricular arrhythmias, and sudden cardiac death.1 Intracardiac pacing studies can be performed in mice using a 1.1F octapolar catheter inserted into the jugular vein, and advanced into the right atrium and ventricle. Here, we illustrate the steps involved in performing programmed electrical stimulation in mice. Surface ECG and intracardiac electrograms are recorded simultaneously in the atria, atrioventricular junction, and ventricular myocardium, whereas intracardiac pacing of the atrium is performed using an external stimulator. Thus, programmed electrical stimulation in mice provides unique opportunities to explore molecular mechanisms underlying conduction defects and cardiac arrhythmias.

Programmed electrical stimulation provides the ability to determine conduction properties of the heart, and the possibility to induce and terminate cardiac arrhythmias using various pacing protocols. Using a transvenous catheter, intracardiac electrogram recordings can be obtained in mice following programmed electrical stimulation protocols to identify arrhythmogenic substrates.

Genetically-modified mice have emerged as a preferable animal model to study the molecular mechanisms underlying conduction abnormalities, atrial and ...

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 ...

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 ...

Breathing-controlled Electrical Stimulation (BreEStim) for Management of Neuropathic Pain and Spasticity

Electrical stimulation (EStim) refers to the application of electrical current to muscles or nerves in order to achieve functional and therapeutic goals. It has been extensively used in various clinical settings. Based upon recent discoveries related to the systemic effects of voluntary breathing and intrinsic physiological interactions among systems during voluntary breathing, a new EStim protocol, Breathing-controlled Electrical Stimulation (BreEStim), has been developed to augment the effects of electrical stimulation. In BreEStim, a single-pulse electrical stimulus is triggered and delivered to the target area when the airflow rate of an isolated voluntary inspiration reaches the threshold. BreEStim integrates intrinsic physiological interactions that are activated during voluntary breathing and has demonstrated excellent clinical efficacy. Two representative applications of BreEStim are reported with detailed protocols: management of post-stroke finger flexor spasticity and neuropathic pain in spinal cord injury.

Breathing-controlled Electrical Stimulation BreEStim for Management of Neuropathic Pain and Spasticity

The purpose is to present a new method, breathing-control electrical stimulation (BreEStim) for management of neuropathic pain and spasticity.

Electrical stimulation (EStim) refers to the application of electrical current to muscles or nerves in order to achieve functional and therapeutic goals. ...

Clinical Assessment of Spatiotemporal Gait Parameters in Patients and Older Adults

Spatial and temporal characteristics of human walking are frequently evaluated to identify possible gait impairments, mainly in orthopedic and neurological patients1-4, but also in healthy older adults5,6. The quantitative gait analysis described in this protocol is performed with a recently-introduced photoelectric system (see&#160;Materials table) which has the potential to be used in the clinic because it is portable, easy to set up (no subject preparation is required before a test), and does not require maintenance and sensor calibration. The photoelectric system consists of series of high-density floor-based photoelectric cells with light-emitting and light-receiving diodes that are placed parallel to each other to create a corridor, and are oriented perpendicular to the line of progression7. The system simply detects interruptions in light signal, for instance due to the presence of feet within the recording area. Temporal gait parameters and 1D spatial coordinates of consecutive steps are subsequently calculated to provide common gait parameters such as step length, single limb support and walking velocity8, whose validity against a criterion instrument has recently been demonstrated7,9. The measurement procedures are very straightforward; a single patient can be tested in less than 5 min&#160;and a comprehensive report can be generated in less than 1&#160;min.

This protocol is used to evaluate spatial and temporal gait variables of neurological/orthopedic patients and older persons by means of a recently-introduced floor-based photocell system.

Spatial and temporal characteristics of human walking are frequently evaluated to identify possible gait impairments, mainly in orthopedic and ...

In vitro Functional Characterization of Mouse Colorectal Afferent Endings

This video demonstrates in detail an in vitro single-fiber electrophysiological recording protocol using a mouse colorectum-nerve preparation. The approach allows unbiased identification and functional characterization of individual colorectal afferents. Extracellular recordings of propagated action potentials (APs) that originate from one or a few afferent (i.e., single-fiber) receptive fields (RFs) in the colorectum are made from teased nerve fiber fascicles. The colorectum is removed with either the pelvic (PN) or lumbar splanchnic (LSN) nerve attached and opened longitudinally. The tissue is placed in a recording chamber, pinned flat and perfused with oxygenated Krebs solution. Focal electrical stimulation is used to locate the colorectal afferent endings, which are further tested by three distinct mechanical stimuli (blunt probing, mucosal stroking and circumferential stretch) to functionally categorize the afferents into five mechanosensitive classes. Endings responding to none of these mechanical stimuli are categorized as mechanically-insensitive afferents (MIAs). Both mechanosensitive and MIAs can be assessed for sensitization (i.e., enhanced response, reduced threshold, and/or acquisition of mechanosensitivity) by localized exposure of RFs to chemicals (e.g., inflammatory soup (IS), capsaicin, adenosine triphosphate (ATP)). We describe the equipment and colorectum&#8211;nerve recording preparation, harvest of colorectum with attached PN or LSN, identification of RFs in the colorectum, single-fiber recording from nerve fascicles, and localized application of chemicals to the RF. In addition, challenges of the preparation and application of standardized mechanical stimulation are also discussed.

In vitro Functional Characterization of Mouse Colorectal Afferent Endings

This video demonstrates a protocol for conducting single-fiber electrophysiological recordings on an in vitro mouse colorectum-nerve preparation.

This video demonstrates in detail an in vitro single-fiber electrophysiological recording protocol using a mouse colorectum-nerve preparation. The ...

Transcutaneous Microcirculatory Imaging in Preterm Neonates

Microcirculatory imaging (MI) is a relatively new research tool mainly used in the intensive care setting. MI provides a clear view of the smallest capillaries, arterioles and venules. The magnifying effect visualizes the flow pattern of erythrocytes through these vessels.
It's non-invasive character makes it suitable to apply in (preterm) neonates, even in cardiorespiratory unstable patients. In adults and children, MI is mainly performed sublingually, but this is not possible in preterm infants as these cannot cooperate and the size of the probe is problematic. In preterm infants, MI is therefore performed transcutaneously. Their thin skin makes it possible to obtain high quality images of peripheral microcirculation. 
In this manuscript we will demonstrate the method of transcutaneous MI in preterm infants. We will focus on the different techniques and provide tips to optimize image quality. The highlights of software settings, safety and offline analysis are also addressed.

Microcirculatory imaging (MI) is used to monitor peripheral perfusion in critically ill or preterm neonates. This manuscript and video demonstrates the optimal approach for obtaining high-quality images.

Microcirculatory imaging (MI) is a relatively new research tool mainly used in the intensive care setting. MI provides a clear view of the smallest ...

The Monoiodoacetate Model of Osteoarthritis Pain in the Mouse

A major symptom of patients with osteoarthritis (OA) is pain that&#160;is triggered by peripheral as well as central changes within the pain pathways. The current treatments for OA pain such as NSAIDS or opiates are neither sufficiently effective nor devoid of detrimental side effects. Animal models of OA are being developed to improve our understanding of OA-related pain mechanisms and define novel pharmacological targets for therapy. Currently available models of OA in rodents include surgical and chemical interventions into one knee joint. The monoiodoacetate (MIA) model has become a standard for modelling joint disruption in OA in both rats and mice. The model, which is easier to perform in the rat, involves injection of MIA into a knee joint that induces rapid pain-like responses in the ipsilateral limb, the level of which can be controlled by injection of different doses. Intra-articular injection of MIA disrupts chondrocyte glycolysis by inhibiting glyceraldehyde-3-phosphatase dehydrogenase and results in chondrocyte death, neovascularization, subchondral bone necrosis and collapse, as well as inflammation. The morphological changes of the articular cartilage and bone disruption are reflective of some aspects of patient pathology. Along with joint damage, MIA injection induces referred mechanical sensitivity in the ipsilateral hind paw and weight bearing deficits that are measurable and quantifiable. These behavioral changes resemble some of the symptoms reported by the patient population, thereby validating the MIA injection in the knee as a useful and relevant pre-clinical model of OA pain.
The aim of this article is to describe the methodology of intra-articular injections of MIA and the behavioral recordings of the associated development of hypersensitivity with a mind to highlight the necessary steps to give consistent and reliable recordings.

Osteoarthritis (OA), or degenerative joint disease, is a debilitating condition associated with pain that remains only partially controlled by available analgesics. Animal models are being developed to improve our understanding of OA-related pain mechanisms. Here we describe the methodology for the monoiodoacetate model of OA pain in the mouse.

A major symptom of patients with osteoarthritis (OA) is pain that&#160;is triggered by peripheral as well as central changes within the pain pathways. The ...

Transcutaneous Assessment of Renal Function in Conscious Rodents

Glomerular filtration rate (GFR) is the gold standard to assess overall kidney function. However, traditional methods to evaluate GFR are cumbersome and time-consuming. In addition, serial blood or urine samples are required, with the associated stress for the experimental animals. A recent technique significantly reduces the investment in time and resources, minimizing the invasiveness and the animal stress, but being equally valid as the traditional approaches. The method measures transcutaneously renal function. Using an optical device and the exogenous renal marker fluorescein isothiocyanate (FITC)-sinistrin, this technique is capable of measuring the elimination kinetics of the marker through the skin. With neither blood nor urine samples nor the associated laboratory assays needed, the results of the transcutaneous measurement are almost instantaneously available. The method has been already validated in different species and successfully applied in several models of renal pathology. Moreover, due to its minimally invasive characteristics, it is suitable for sequential measurements within the same animal. Here is provided a detailed protocol to carry out the transcutaneous assessment of renal function in rodents.

Determination of glomerular filtration rate (GFR) is the gold standard to assess overall kidney function. However, traditional procedures to measure this parameter are cumbersome and require a large investment of time. Here we describe a faster and minimally invasive method to determinate GFR transcutaneously.

Glomerular filtration rate (GFR) is the gold standard to assess overall kidney function. However, traditional methods to evaluate GFR are cumbersome and ...

Subcutaneous Trigeminal Nerve Field Stimulation for Refractory Facial Pain

Chronic or neuropathic trigeminal facial pain can be challenging to treat. Neurosurgical procedures should be applied when conservative treatment fails. Neuromodulation techniques for chronic facial pain include deep brain stimulation and motor cortex stimulation, which are complex to perform. Subcutaneous nerve field stimulation is certified for chronic back pain and is the least invasive form of neuromodulation. We applied this technique to treat chronic and neuropathic trigeminal pain as an individual therapy concept. First, trial stimulation is performed. Subcutaneous leads are placed in the painful trigeminal dermatome under local anesthesia. The leads are connected to an external neurostimulator that applies constant stimulation. Patients undergo a 12 day outpatient trial to assess the effect of the stimulation. Electrodes are removed after the trial. If the patient reports pain reduction of at least 50% in intensity and/or attack frequency, a reduction in medication or increase in quality of life, permanent implantation is scheduled. New electrodes are implanted under general anesthesia and are subcutaneously tunneled to an infraclavicular internal pulse generator. Patients are able to turn stimulation on and off and to increase or decrease the stimulation amplitude as needed.
This technique represents a minimal invasive alternative to other more invasive means of neuromodulation for trigeminal pain such as motor cortex stimulation or deep brain stimulation.

Treating chronic or neuropathic facial pain can be challenging when medical or standard treatment fails. Subcutaneous nerve field stimulation is the least invasive form of neuromodulation and is used for chronic back pain. We applied this technology to treat chronic and neuropathic trigeminal facial pain.

Chronic or neuropathic trigeminal facial pain can be challenging to treat. Neurosurgical procedures should be applied when conservative treatment fails. ...