Quantitative Sensory Testing Instruments For Pain Management

Thermode and Quantitative Sensory Testing (QST)

Pressure point threshold is defines as the minimum force, which is needed to induce pain in individuals. This is the measure of tenderness and there is a scale that is used to measure the tenderness in individuals. This scale is known as Quantitative Sensory Testing (QST), which is used to measure the pain and different pain related diseases. The characteristics of QST includes a thermal and a vibratory stimulator technology. A small ‘thermode’ is attached to the patient’s body and then the device starts cooling or heating by the usage of an electrical current. The specificity and sensitivity of the QST is to study the physiological and anatomical level of pain threshold and pathological sensory (Ziaeifar et al., 2014). It also helps to measure the pharmacological or non-pharmacological therapeutic strategies under different clinical and experimental conditions. It also distinguishes between different pain thresholds having similar symptomatic pattern. According to Stabell et al., (2014) the test was performed with 1117 students and after excluding participants based on their age (18 and above were excluded), 961 final participants were selected and a series of tests were performed with them. These tests were heat pain threshold and tolerance (HPTT), pressure pain threshold, cold pressure pain tolerance and tolerance in two body sites. Within this population, 8.2 percent was suffering from Irritable Bowel Syndrome (IBS) symptoms. HPTT was measured using MEDOC ATS sensory stimulator and stimulation was applied on volar surface of right forearm. Threshold was measured according to the maximum tolerable pain determined by the participants. Furthermore, the cold pressure was measured using 3 degree Celsius water bath namely Julabo PF-40-HE and participants submerged their hand in the water. The time of withdrawal was noted as the threshold. The test result was analyzed using SPSS version 20 instrument used for Chi square and T-test (Stabell et al., 2014). There are several QST scales are available in market such as VSA-3000 vibratory sensory analyzer, and the time taken for each test is around 5 to 10 minutes. This scale is automated and to perform the test, no technical expertise is important. The device helps to produce an automated data summary with graphic report generation. The device utilizes different test methods such as limits, levels and manual test method. There are a range of diseases in which this device can be used for analysis such as carpal tunnel syndrome, diabetic neuropathy, lumbar radiculopathies and peripheral neuropathies. As the test is easy to perform and does not require any expert or trained personnel to perform, this can be performed anyone such as general physician, practice assistant, physiotherapist, nursing staff and so on (Suokas et al., 2012).

Electrical Stimulator for Muscle Activation and Pain Management Therapies

Electrical stimulator is an instrument that is used to apply the electric stimulator therapy to treat muscle spasm and pain using electrical stimulation. It is usually applied in enhancing muscle strength for patients with injuries. It is also useful in keeping the muscle active while recovering from cold strokes and injuries. The sensitivity and specificity of this measuring instrument is for physiological injuries, nervous activation and pain management therapies. There are several type of stimulation therapy used for muscle activation and injury analysis in patients. Transcutaneous electrical neuromuscular stimulation is a physical therapy, which is used to manage acute pain in physiological therapy. According to the experiment of Neziri et al., (2013), electrical stimulation was used to understand the level of chronic pain of neck and stimulation was to control the asymptomatic control subject. Different electrical stimulation results helps to discriminate between different level of pain and first three of the pain stimulation from the neck as used to understand the severity of neck pain. Pain detection and tolerance threshold was measured using an electrical pressure algometer and the threshold point, in which pressure becomes pain, was measured. For the stimulation, TSA-II MEDOC was used in which maximum heat stimulation was 50 degree and minimum was 0 degree Celsius. The Stimulation was done on the innervation area of the sural nerve. As the stimulator was computer-controlled constant current stimulator, the reflexes were recorded in the computer and the data was stored after statistical analysis (Neziri et al., 2013). The several instruments that are needed for the electrical stimulation test are neuromuscular electrical stimulation machine, iontrophoresis device, and transcutaneous electrical neuromuscular stimulation device and so on that are being used to analyze and monitor different acute injuries. These therapies generally takes 30 to 45 minutes to perform and electrical stimulation should reach its target nerve or muscle for faster and long-lasting effects. There are different companies who produce electrical stimulation within which, aurora scientific is going to be discussed. 701C: electrical stimulator is the product of this company that is used for the electrical stimulator for different quantitative sensory testing for pain and discomfort (Miklas et al., 2014). The features of this product is full automation and constant current and voltage mode with positive negative and bi-phase output. The rise and fall time is less than 5 micron second that leads to analyses small impulse of pain and helps to distinguish between different similar pain related symptoms. The only complexity of this device or measuring instrument is its productivity. The spots where the nervous or muscle injury occurred, should be impulse with proper amount of electrical stimulation. Therefore, the person performing the analysis should be trained in this task and people with less and no experience of this analysis should not be given with the opportunity to perform it.

Dolorimeter and Measuring Heat and Cold-Related Pains

Several instruments are used to determine heat pain sensitivity, cold pressure and heat shock tolerance. An example of such instrument is dolorimeter, which is used to measure the heat related pain threshold and the tolerance to cold or heat shock related pain. There are different kind of dolorimeter are available in the market. The specificity and sensitivity of dolorimeter is to determine heat related shocks or pains in human body. It uses steady pressure, steady electrical current, to produce heat and the generated heat determines the level of pain. At times, the device applies pressure using a blunt object (Lopes Frutos et al., 2012). The object increases the pressure at a point of body and then the heat is generated by pressing a sharp object to the body. Kuni et al., (2015) has presented an experiment, in which, the researchers were analyzing pain threshold with functional scores in osteoarthritis patients. The researchers included 50 patients with knee osteoarthritis and 49 patients with hip osteoarthritis with 15 control patients. Before starting the test, the current medication and VAS for testing was assessed. The assessment was done based on different questionnaires such as VAS, American Knee Society Score 1 and 2, Oxford knee score and Harris Hip Score. Pressure point algometer was used to determine the pressure threshold and the patients were advised to stop the algometer according to their pain threshold and discomfort. After completing the pain measurement, it was found that lower pressure pain was found in 26 patients of knee osteoarthritis and 17 of hip osteoarthritis. Statistical analysis was done to get the result and for accuracy, the significance level was set at 5% (Kuni et al., 2013). There are different instruments that are being used for the temperature measurement in patients (Usamentiaga et al., 2014). These instruments are used to measure different type of pains such as somatic pain that is caused by activation of pain management, visceral pain that happens when the organs are damaged or injured. The final pain it can measure is the neuropathic pain, which is caused by injured spinal cord. Injury to other organs are also can be measured such as back, feet, thighs and toes. Dolorimeter is the device that is used to measure pain. It uses pressure and temperature to measure the level of pain. The benefit of using this device to detect the physical or neurological pain is the automated nature (Harte et al., 2013). The machine does not require any trained or expert professional to operate it. Therefore, any professional such as general physician, practice assistant or physiotherapist can use this device to measure the level or acute pain in patients.

Electromyography Nerve Study for Touch Sensitivity Measurement

There are several quantitative sensory testing available to determine the touch as the measurement of pain. The method that is used for the diagnostic study is known as the electromyography nerve study. This measuring instrument is utilized to evaluate the function of large myelinated nerve fibers such as the motor nerves, which helps to understand the touch. It is specific for the nerves, which is related to pain and acute injury as the small myelinated nerves, or unmyelinated nerves are not responsible for pain related sensations and without the involvement of motor nerves. This pain related sensations are measured through the quantitative sensory testing is a non-invasive technique to assess the nerve damage by measuring the threshold of pressure, which is felt on skin (Weiss, Weiss & Silver, 2015). This quality sensory testing is specific for the sensory stimuli and thermal stimuli. There are two types of sensory testing devices, which utilizes touch related sensory to determine the level of pain. These are current perception threshold and a pressure specific sensory device. An area of the skin has been chosen for specific nerve. The nerve damage can be measured by the amount of pressure needed for the person to feel the touch. The test is repeated several times to make an average of the threshold pain level and then the further is carried out (Collin et al., 2014). In the experiment by Hilgenberg-Sydney, Kowacs &Conti (2016), 613 women were seleceted for the assessment and usage of analgesics prior to the test was prohibited. These women were divided into groups according to their pain level and with the help of pain algometer, the level of reflex upon touch of pain sensation was determined. Further, for the CPT test was assessed based on readings of neurometer. The analysis was done based on the differences between the pain levels in groups. The test, process is pain-free and no electrical stimulation is used in this process.

The device, which is used, for the determination of pain level using touch is known as electromyography device and using this device is easy and compatible as no expertise or training is required to handle it (Hilgenberg-Sydney, Kowacs &Conti, 2016). Therefore, any professional such as general physicians, physiotherapist or nursing staff can carry out the test on patients having acute pain. This QST has been used in a broad range of healthcare related interventions, which includes detection of carpal tunnel syndrome, tarsal tunnel syndrome, diabetic neuropathy and quantification of hypo esthetic conditions (Kimura, 2017).

To conclude, it can be stated that quantitative sensory testing is a major subject that encompasses a wide range of measures and testing. These measures are applied on different acute pain related issues. This assignment discussed about four sensory issues, such as, touch, temperature, pressure point threshold and electrical stimulation. Several aspects of these measurements were resented in this assignment, such as their characteristics, cost, usage and it can be deduced that a high level of expertise is needed to operate these devices.

References

Collin, P., Treseder, T., Lädermann, A., Benkalfate, T., Mourtada, R., Courage, O., & Favard, L. (2014). Neuropathy of the suprascapular nerve and massive rotator cuff tears: a prospective electromyographic study. Journal of shoulder and elbow surgery, 23(1), 28-34.

Harte, S. E., Mitra, M., Ichesco, E. A., Halvorson, M. E., Clauw, D. J., Shih, A. J., & Kruger, G. H. (2013). Development and validation of a pressure-type automated quantitative sensory testing system for point-of-care pain assessment. Medical & biological engineering & computing, 51(6), 633-644.

Kimura, J. (2017). Nerve conduction studies. Oxford Textbook of Clinical Neurophysiology, 49-66.

Kuni, B., Wang, H., Rickert, M., Ewerbeck, V., & Schiltenwolf, M. (2015). Pain threshold correlates with functional scores in osteoarthritis patients. Acta orthopaedica, 86(2), 215-219.

Lopes Frutos, A., Fomentão Araújo, B., Alves da Silva, E. A., & Flor Bertolini, G. R. (2012). Pain threshold assessment in relation to neural mobilization therapy. Acta Scientiarum. Health Sciences, 34.

Miklas, J. W., Nunes, S. S., Sofla, A., Reis, L. A., Pahnke, A., Xiao, Y., … & Radisic, M. (2014). Bioreactor for modulation of cardiac microtissue phenotype by combined static stretch and electrical stimulation. Biofabrication, 6(2), 024113.

Neziri, A. Y., Limacher, A., Jüni, P., Radanov, B. P., Andersen, O. K., Arendt-Nielsen, L., & Curatolo, M. (2013). Ranking of tests for pain hypersensitivity according to their discriminative ability in chronic neck pain. Regional anesthesia and pain medicine, 38(4), 308-320.

Stabell, N., Stubhaug, A., Flægstad, T., Mayer, E., Naliboff, B. D., & Nielsen, C. S. (2014). Widespread hyperalgesia in adolescents with symptoms of irritable bowel syndrome: results from a large population-based study. The Journal of Pain, 15(9), 898-906.

Suokas, A. K., Walsh, D. A., McWilliams, D. F., Condon, L., Moreton, B., Wylde, V., … & Zhang, W. (2012). Quantitative sensory testing in painful osteoarthritis: a systematic review and meta-analysis. Osteoarthritis and Cartilage, 20(10), 1075-1085.

Usamentiaga, R., Venegas, P., Guerediaga, J., Vega, L., Molleda, J., & Bulnes, F. G. (2014). Infrared thermography for temperature measurement and non-destructive testing. Sensors, 14(7), 12305-12348.

Weiss, J. M., Weiss, L. D., & Silver, J. K. (2015). Easy EMG: a guide to performing nerve conduction studies and electromyography. Elsevier Health Sciences. https://books.google.co.in/books?hl=en&lr=&id=o-d1BwAAQBAJ&oi=fnd&pg=PP1&dq=electromyography+nerve+study&ots=KjL13JU0Qi&sig=Za4QYEWI8o9Onf1cS5yfwbOAhVY#v=onepage&q=electromyography%20nerve%20study&f=false

Ziaeifar, M., Arab, A. M., Karimi, N., & Nourbakhsh, M. R. (2014). The effect of dry needling on pain, pressure pain threshold and disability in patients with a myofascial trigger point in the upper trapezius muscle. Journal of bodywork and movement therapies, 18(2), 298-305.