Examining penile sensitivity in neonatally circumcised and intact men using quantitative sensory testing
The study is assessing penile sensitivity in circumcised and intact men by testing tactile and thermal thresholds at control site and few penile sites. The results demonstrate that circumcision procedure does not influence penile sensitivity and suggest that the foreskin is not the most sensitive part of the penis.
Neonatal circumcision is quite a widely used procedure, which causes a lot of debates on topic of its pros and cons. Among the potential benefits of the procedure is, for example, reduction of urinary tract infections, protection against sexually transmitted infection, etc. One of the concerns related to neonatal circumcision is a possible influence on sexual function, in particular, reduction of penile sensitivity.
The aim of this study was to assess penile sensitivity of neonatally circumcised and intact male by comparing the functionality of their peripheral nerves. For that purpose 30 circumcised and 32 intact men were recruited ant tested with QST protocol, which included assessing of tactile and pain thresholds by von Frey filaments and warm detection and heat pain thresholds by Medoc’s TSA device with small, 5×5 mm thermode used. The testing was performed on neutral site (wrist) and on 3-4 penile sites.
The findings of the study demonstrated that neither of the tested parameters differed with respect to circumcision status, meaning the neonatal circumcision is not associated with penile sensitivity decrease. The findings are important and may influence the decisions of the male-babies parents and policy makers on topic of neonatal circumcision.
This week the Ruppin College hosted a unique skills day within the framework of “Young Israeli Entrepreneurs”. The children learned along the day about entrepreneurship, management, branding and defining roles, as well as raised funds for various purposes. Medoc accompanies the program, and the participants will soon be invited to a special day at the company’s offices.
I am pleased to announce the appointment of Mr. David Gutmacher to the position of Operation & Service Manager of the Medical Systems Division ( QST Division), effective Jan. 1st, 2016.
Since joining the company in Dec 2010, David has significantly strengthened the level and quality of our service commitment to Medoc customers. David has done so, while also playing an expanded role in operational areas beyond the service function.
It is only natural that David receives this promotion, which is reflective of the confidence management has in his future and even wider contributions at Medoc.
Please join me in wishing David the very best in his new and important position
Amir Haiman, General Manager
Medoc Ltd, Advanced Medical Systems Division
Last September, at the 9th EFIC Pain Meeting, Medoc had sponsored a CPM Recommendation Meeting, organized and headed by Prof. Yarnitsky (Rambam Medical Center, Israel). This meeting is a follow up meeting to a previous CPM session, held during 2 years ago (2013) at the 8th EFIC meeting in Florence. Over 25 participants, KOLs in the field of CPM, attended this meeting trying to formulate additional recommendations for CPM method used for CPM studies. Some KOLs presented their way of doing CPM and the tools they use in their studies (cold/hot water bath, thermal probe, pressure algometer, blood pressure calf etc). The session gave the CPM specialist a great platform to address important questions such as the specifications of test and conditioning stimuli, distraction role, attempts to reach a standard CPM protocol, etc. Some of the participants shared the data they have collected, comparing different CPM methods, and their studies results. Medoc was pleased to sponsor this meeting and to get the CPM research community sharing their knowledge and take on this important subject.
Methods to Measure Peripheral and Central Pain Sensitization Using Quantitative Sensory Testing: A Focus on Individuals with Low Back PainThis paper proposes a standardized method for performing various modalities of quantitative sensory testing (QST) in patients with low back pain. It concludes that such QST protocol can help to evaluate the mechanisms of low back pain – central and peripheral – and can be used for individualized treatment, based on the mechanism involved. Angela R. et al. Muscle Nerve. 2014.
Quantitative sensory testing (QST) is a non-invasive method to evaluate the function of large and small nerve fibers and of peripheral and central sensory pathways. QST is used in many researches for various approaches, but standardization of the protocol is sometimes missing. This article’s purpose is to provide a standard protocol for using QST in patients with low back pain (LBP). The QST measures described in this paper are mechanical pain threshold and pain tolerance, mechanical temporal summation, dynamic mechanical allodynia; vibration detection threshold; thermal testings’ including warm and cold detection thresholds and heat and cold pain thresholds; conditioned pain modulation test (with thermal test and conditioning stimuli); thermal temporal summation; pressure pain threshold. The paper describes the protocol for each measurement, equipment used and analysis techniques. The paper emphasizes the importance of the measurement standardization, raises further steps that need to be taken to implement QST into the clinical practice and suggests that QST can be used for various approaches – detecting individual pain perception differences, dividing between peripheral and central mechanisms of pain, etc. – and also can serve to develop personalized treatment based on the individual pain mechanism and to evaluate the treatment effectiveness.
A Randomized Controlled Trial on the Effect of Tapentadol and Morphine on Conditioned Pain Modulation in Healthy Volunteers
The aim of this study was to evaluate the effect of tapentadol and morphine on descending pain inhibition, represented by CPM test, in healthy volunteers. The results demonstrated that morphine affects CPM while tapentadol has no effect on CPM, confirming the different mechanism of action of the two drugs.
Chris M. et al. 2015.
Tapentadol and morphine are both opioid analgesics, tapentadol is a combined μ-opioid receptor (MOR) agonist and noradrenaline reuptake inhibitor; morphine is a strong mu-opioid receptor agonist without significant effect on noradrenaline reuptake. This study evaluated the influence of the above analgesic drugs on conditioning pain modulation (CPM) in healthy individuals and, based on the existing data, suggested that morphine will cause reduced CPM responses and tapentadol increased ultram 50mg. All 12 healthy volunteers attended 3 sessions, in each they were treated with different drug (placebo, tapentadol and morphine) and then CPM test was performed 60–90 and 120–150 min after drug intake. The results demonstrated that morphine reduced CPM responses in comparison to placebo (by 80%) and tapentadol, in contrast to the hypothesis, had no effect on CPM responses compared to placebo treatment. The paper suggests various possible explanations of these findings. The data presented in the paper confirms the difference in main mechanism of action of the two drugs and suggests a possible explanation for these underlying mechanisms.
This study presents age- and body region-specific normative data for thermal threshold testing and investigates the factors which may influence the reference values. Normative data presented in this study can be easily applied in clinical practice. Thermal QST is a useful tool for assessment of small fibers function and therefore can be used for small fiber neuropathies diagnosis and monitoring.
Hafner J. et al. 2015.
Clinically useful, age- and body region-specific normative data for thermal QST was collected from large population (101 healthy volunteers), for hand and foot, for warm and cold sensation modalities. Data was collected by three operators, using two different TSA II systems. Warm and cold sensation thresholds were assessed using a method of Limits with standard parameters – baseline temperature 32˚C, temperature changing rate of 1˚C per second. Each modality was measured five times at each site, with 4-6 sec between trials; warm detection threshold was followed by cold detection threshold. Additional study was performed on 10 subjects, using the two TSA II machines, by a single operator, so that all the subjects were tested by both machines. This small study demonstrated that there is no difference between the data collected on different TSA II machines. This study demonstrates the influence of the age and body region on normal values and presents normative data for thermal QST, which can be easily applied in clinical practice, contributing to the usage of thermal QST for diagnosis and monitoring of small fiber neuropathies.
This study investigates the difference in quantitative sensory testing results and self-reported neuropathic pain in patients after Total Knee Arthroplasty surgery with and without persistent pain. The results demonstrate that patients with persistent post-operative pain demonstrate widespread mechanical, cold and heat hyperalgesia and also higher level of neuropathic-like pain.
Wright A. et al. 2015.
Total Knee Arthroplasty causes pain relief and improves the functionality, however up to 15% of the patients suffer from persistent post-operative pain after the surgery. The aim of this study was to determine if such persistent pain is associated with neuropathic-like pain and QST impairments. To answer the above questions 53 patients after TKA surgery were recruited, some with moderate to severe pain and some without pain. Patients completed self-report questionnaires and went through QST, including pressure pain threshold, cold and heat pain threshold and cold and warm detection threshold tests on the operated knee and on distant elbow. The results demonstrated that there was an association between moderate to severe pain reported after the surgery and widespread mechanical and cold and heat hyperalgesia. Patients with persistent pain also demonstrated higher levels of neuropathic-type pain and less improvement after the surgery. The results suggest that some patients after TKA surgery continue to suffer from knee pain and dysfunction and raises a need for larger study assessing these patient pre and postoperatively.
Dynamic Pain Phenotypes are associated with Spinal Cord Stimulation-Induced Reduction in Pain: A Repeated Measures Observational Pilot StudyThis study investigates the effect of Spinal Cord Stimulation (SCS) on sensory processing of chronic pain patients and demonstrates that enhanced central sensitization and reduced conditioned pain modulation (CPM) correlate with more effective pain relief by SCS.
Campbell C. et al. Pain med 2015.
Spinal Cord Stimulation (SCS) is a promising and gaining popularity treatment for various pain conditions. Its mechanism is currently not well understood. In the current study a battery of tests was performed on 24 patients with a range of chronic-pain conditions suitable for SCS treatment. The testing procedure included assessment of pain thresholds, allodynia, cold pressor test, CPM, mechanical and thermal temporal summation before SCS, during trial stimulation, 1 and 3 months following permanent implantation. The results of this study demonstrated that both central sensitization, represented by the results of the temporal summation test, and CPM were associated with the level of pain after 3 months of SCS stimulation. The results suggest that patients with greater central sensitization and less efficient CPM at baseline will gain more benefit from SCS treatment. The above results throw a light on the potential mechanism of SCS treatment and suggest that dynamic sensory testing (temporal summation, CPM) may be used in the future to categorize the candidates for the treatment and to detect those for whom this treatment will be most useful and effective.
Effects of Spinal Cord Stimulation on Pain Thresholds and Sensory Perceptions in Chronic Pain Patients
This paper evaluates the influence of Spinal Cord Stimulation (SCS) on the sensory and pain perception in chronic pain patients and demonstrates changes in Quantitative Sensory Testing results during SCS activation, both on painful and non-painful area, providing additional information on SCS treatment mechanism.
Ahmed SU. et al. Clinical Neuromodulation. 2015
Spinal Cord Stimulation treatment has been used for pain relief in different pain conditions, but the evidences of its impact on pain and sensory thresholds are conflicting. The aim of this study was to quantify the influence of SCS on warm detection threshold (WDT), heat pain threshold (HPT) and heat pain tolerance on both painful and non-painful areas. 19 patients with SCS device implanted were tested with two sets of QST – one with SCS off and one 20 minutes after the SCS was turned on. The results demonstrated that the values of all the testing modalities (WDT, HPT and heat tolerance threshold) were increased when the SCS was on, both on painful and non-painful areas. The fact that there was an increase in sensation and pain thresholds on non-painful area suggests that there is a role of central influence of SCS treatment..