Diagnostic Blocks Research Articles

Radiofrequency Ablation for Chronic Knee, Hip, and Shoulder Pain


 For patients with knee osteoarthritis (OA), radiofrequency ablation may reduce pain and improve function compared to other nonsurgical interventions without increasing adverse events.
 There is insufficient evidence to suggest that radiofrequency ablation reduces pain or improves function among patients with chronic hip pain.
 We did not find any studies or guidelines on the clinical effectiveness of radiofrequency ablation for treating chronic shoulder pain that met the inclusion criteria for this review.
 Three guidelines conditionally recommend the use of radiofrequency ablation for patients with knee OA, and 1 guideline conditionally recommends the use of radiofrequency ablation for hip joint pain following diagnostic blocks.

The use of Pulsed Radiofrequency in the treatment oftrigeminal neuralgia and painful trigeminal neuropathy –two clinical cases

Trigeminal neuralgia, one of the pain conditions with severe pain, can be effectively treated with pharmacotherapyand invasive methods of pain treatment (at the level of the peripheral nerve, Gasser's ganglion, or nerve root). Painfultrigeminal neuropathy is defined as facial pain in one or more branches of the trigeminal nerve caused by otherconditions or damage to the nerve. This condition can be effectively treated with individual pharmacotherapy andnon-pharmacological methods, and in some cases, invasive methods. In both diseases, many treatment methodscan be proposed, including the minimally invasive procedure of pulsed radiofrequency (PRF). The following studypresents two cases of successful therapy using pulsed radiofrequency of the peripheral branches of the trigeminalnerve in patients with trigeminal neuralgia and painful trigeminal neuropathy. Prior to the procedure, pain relief wasobtained in the painful branches of the trigeminal nerve after a diagnostic block. pulsed radiofrequency is a minimallyinvasive, safe for the patient treatment method.

Feasibility of Ultrasound Measurements of Peripheral Sensory Nerves in Head and Neck Area in Healthy Subjects.

Current diagnostic methods for nerve compression headaches consist of diagnostic nerve blocks. A less-invasive method that can possibly aid in the diagnosis is ultrasound, by measuring the cross-sectional area (CSA) of the affected nerve. However, this technique has not been validated, and articles evaluating CSA measurements in the asymptomatic population are missing in the current literature. Therefore, the aim of this study was to determine the feasibility of ultrasound measurements of peripheral extracranial nerves in the head and neck area in asymptomatic individuals. The sensory nerves of the head and neck in healthy individuals were imaged by ultrasound. The CSA was measured at anatomical determined measurement sites for each nerve. To determine the feasibility of ultrasound measurements, the interrater reliability and the intrarater reliability were determined. In total, 60 healthy volunteers were included. We were able to image the nerves at nine of 11 measurement sites. The mean CSA of the frontal nerves ranged between 0.80 ± 0.42 mm2 and 1.20 ± 0.43 mm2, the mean CSA of the occipital nerves ranged between 2.90 ± 2.73 mm2 and 3.40 ± 1.91 mm2, and the mean CSA of the temporal nerves ranged between 0.92 ± 0.26 mm2 and 1.40 ± 1.11 mm2. The intrarater and interrater reliability of the CSA measurements was good (ICC: 0.75-0.78). Ultrasound is a feasible method to evaluate CSA measurements of peripheral extracranial nerves in the head and neck area. Further research should be done to evaluate the use of ultrasound as a diagnostic tool for nerve compression headache.

The Effectiveness of Medial Branch Blocks and Radiofrequency Neurotomy in Managing Chronic Thoracic Pain: A Systematic Review and Meta-Analysis

BACKGROUND: Extensive research into potential sources of thoracic pain with or without referred pain into the chest wall has demonstrated that thoracic facet joints can be a potential source of pain confirmed by precise, diagnostic blocks. The objective of this systematic review and meta-analysis is to evaluate the effectiveness of medial branch blocks and radiofrequency neurotomy as a therapeutic thoracic facet joint intervention. METHODS: Systematic review and meta-analysis of randomized controlled trials (RCTs) and observational studies of medial branch blocks and the radiofrequency neurotomy in managing thoracic pain utilizing the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist was performed. A comprehensive literature search of multiple databases of RCTs and observational studies of medial branch blocks and radiofrequency neurotomy in managing chronic thoracic pain were identified from 1996 to December 2022 with inclusion of manual searches of the bibliography of known review articles and multiple databases. Methodologic quality and risk of bias assessment was also conducted. Evidence was synthesized utilizing principles of quality assessment and best evidence synthesis, with conventional and single meta-analysis. The primary outcome measure of success was 3 months of pain reduction for medial branch blocks and 6 months for radiofrequency thermoneurolysis for a single treatment. Short-term success was defined as up to 6 months and long-term was more than 6 months. RESULTS: This literature search yielded 11 studies meeting the inclusion criteria, of which 3 were RCTs and 8 were observational studies. Of the 3 RCTs, 2 of them assessed medial branch blocks and one trial assessed radiofrequency for thoracic pain. The evidence for managing thoracic pain with qualitative analysis and single-arm meta-analysis and GRADE system of appraisal, with the inclusion of 2 RCTs and 3 observational studies for medial branch blocks was Level II. For radiofrequency neurotomy, with the inclusion of one RCT of 20 patients in the treatment group and 5 observational studies, the evidence was Level III in managing thoracic pain. LIMITATIONS: There was a paucity of literature with RCTs and real-world pragmatic controlled trials. Even observational studies had small sample sizes providing inadequate clinically applicable results. In addition, there was heterogeneity of the available studies in terms of their inclusion and exclusion criteria, defining their endpoints and the effectiveness of the procedures. CONCLUSION: This systematic review and meta-analysis show Level II evidence of medial branch blocks and Level III evidence for radiofrequency neurotomy on a long-term basis in managing chronic thoracic pain. KEY WORDS: Chronic spinal pain, thoracic facet or zygapophysial joint pain, facet joint nerve blocks, medial branch blocks, controlled comparative local anesthetic blocks, diagnostic accuracy, radiofrequency neurotomy

A study to forecast healthcare capacity dynamics in the wake of the COVID-19 pandemic

PurposeThis study aims to evaluate the dynamics between healthcare resource capacity expansion and disease spread. Further, the study estimates the resources required to respond to a pandemic appropriately.Design/methodology/approachThis study adopts a system dynamics simulation and scenario analysis to experiment with the modification of the susceptible exposed infected and recovered (SEIR) model. The experiments evaluate diagnostic capacity expansion to identify suitable expansion plans and timelines. Afterwards, two popularly used forecasting tools, artificial neural network (ANN) and auto-regressive integrated moving average (ARIMA), are used to estimate the requirement of beds for a period when infection data became available.FindingsThe results from the study reflect that aggressive testing with isolation and integration of quarantine can be effective strategies to prevent disease outbreaks. The findings demonstrate that decision-makers must rapidly expand the diagnostic capacity during the first two weeks of the outbreak to support aggressive testing and isolation. Further, results confirm a healthcare resource deficit of at least two months for Delhi in the absence of these strategies. Also, the study findings highlight the importance of capacity expansion timelines by simulating a range of contact rates and disease infectivity in the early phase of the outbreak when various parameters are unknown. Further, it has been reflected that forecasting tools can effectively estimate healthcare resource requirements when pandemic data is available.Practical implicationsThe models developed in the present study can be utilised by policymakers to suitably design the response plan. The decisions regarding how much diagnostics capacity is needed and when to expand capacity to minimise infection spread have been demonstrated for Delhi city. Also, the study proposed a decision support system (DSS) to assist the decision-maker in short- and long-term planning during the disease outbreak.Originality/valueThe study estimated the resources required for adopting an aggressive testing strategy. Several experiments were performed to successfully validate the robustness of the simulation model. The modification of SEIR model with diagnostic capacity increment, quarantine and testing block has been attempted to provide a distinct perspective on the testing strategy. The prevention of outbreaks has been addressed systematically.

Ability of diagnostic injection to predict surgical outcomes in patients with chronic low back pain and lumbar radiculopathy

BackgroundArising from different anatomical structures of the spine, chronic low back pain is one of the leading causes of disability, and its management is still controversial. Thus, appropriate and effective management of chronic low back pain requires a precise diagnostic tool in order to target pain generators. Therefore, the role of diagnostic injection in predicting the outcome of surgical treatment of chronic low back pain and lower limb radicular pain need to be evaluated in order to guide the surgeon, especially in case of unclear pathoanatomical features. Thus, the aim of this study was to assess the predictive value of lumbar spine diagnostic injections in surgical outcome in patients with chronic low back pain and lumbar radiculopathy.Patients and methodsThis study included 30 patients complaining of chronic low back pain and/or lumbar radiculopathy who underwent lumbar spine surgery following positive diagnostic injections. The pre- and postoperative assessments consisted of a general neurological examination, evaluation of the Oswestry disability index, and a visual analog scale.ResultsThis prospective non-controlled study was conducted on 30 patients complaining of chronic low back pain and/or lumbar radiculopathy. The mean age was 42.60 ± 8.27 years with a range of 24.0–62.0 years. The visual analog scale decreased significantly from preoperative mean value of 8.26 ± 0.79 to postoperative mean value of 1.97 ± 0.92; with almost two-thirds of the patients experienced more than 75% pain reduction. The Oswestry disability index decreased significantly from preoperative mean value of 34.13 ± 4.88 to 11.47 ± 3.36 after surgery in the whole sample. The post-selective nerve root block visual analog scale was significantly correlated to the postoperative visual analog scale, while the postoperative Oswestry disability index was not significantly associated with the post-selective nerve root block visual analog scale.ConclusionThe use of lumbar selective nerve root block and lumbar provocative discography for patients with chronic low back pain and radiculopathy and equivocal radiological findings can improve surgical outcomes regarding pain intensity and spine functional outcomes. Diagnostic selective nerve root block can predict the postoperative pain relief.

Conventional Radio-frequency Ablation in Laminectomy- and Discectomy-induced Complex Regional Pain Syndrome

Abstract Complex regional pain syndrome (CRPS) following lumbar spine surgery is a rare and underdiagnosed clinical entity. This case report discusses CRPS of the left lower limb following lumbar spine laminectomy and discectomy done for left lumbar radiculopathy secondary to disc herniation. CRPS was diagnosed by the exclusion of other possible diagnoses. The Budapest Criteria were applied for a definitive diagnosis. We treated the patient with conventional radio-frequency ablation of the sympathetic ganglion at L2 and L4 after a successful diagnostic block. He had significant relief in pain for the next 6 months.

Spinal Injections: A Narrative Review from a Surgeon's Perspective.

Spinal pain is one of most frequent complaints of the general population, which can cause decreased activities of daily living and absence from work. Among numerous therapeutic methods, spinal injection is one of the most effective treatments for spinal pain and is currently widely applied in the clinical field. In this review, spinal injection is discussed from a surgeon's perspective. Recently, although the number of spinal surgeries has been increasing, questions are arising as to whether they are necessary. The failure rate after spinal surgery is high, and its long-term outcome was reported to be similar to spinal injection. Thus, spinal surgeries should be performed conservatively. Spinal injection is largely divided into diagnostic and therapeutic blocks. Using diagnostic blocks, such as the diagnostic selective nerve root block, disc stimulation test, and diagnostic medial branch block (MBB), the precise location causing the pain can be confirmed. For therapeutic blocks, transforaminal nerve root injection, therapeutic MBB, and percutaneous epidural neuroplasty are used. When unbearable spinal pain persists despite therapeutic spinal injections, spinal surgeries can be considered. Spinal injection is usefully used to identify the precise location prior to a patient undergoing injection treatment or surgery and can reduce pain and improve quality of life, and help to avoid spinal surgery. Pain physicians should treat patients with spinal pain by properly utilizing spinal injection.

Ultrasound-guided lateral pericapsular hip desensitization of the articular branches of the cranial gluteal nerve: A canine cadaveric study and feasibility study in dogs

ObjectiveTo develop and assess the feasibility, as a diagnostic block, of an ultrasound-guided lateral pericapsular hip desensitization (L-PHD) technique in dogs. Study designProspective, randomized, anatomical and feasibility study. AnimalsA total of 11 canine cadavers and eight adult dogs scheduled for acetabular surgical denervation. MethodsAfter studying the ultrasound anatomy of the lateral aspect of the gluteal region and determining an acoustic window to perform an ultrasound-guided L-PHD in three canine cadavers, the right and left hemipelves of eight canine cadavers were injected in the interfascial plane located lateral (LL-PHD group) or medial (LM-PHD group) to the deep gluteal muscle, with 0.05 mL kg–1 of dye per hip on each cadaver. The staining of the pericapsular nerves was assessed by anatomical dissection. Then, the LM-PHD was performed using 2% lidocaine as a diagnostic block in dogs scheduled for acetabular surgical denervation. Positive predictive value (PPV) was calculated for those animals who had favorable outcomes after acetabular surgical denervation. ResultsThe ultrasound-guided LL-PHD and LM-PHD could be performed by inserting the needle lateral and medial to the deep gluteal muscle. Ultrasound-guided LL-PHD stained the cranial gluteal nerve and its muscular branches in all injections and partially stained the lumbosacral trunk in two out of eight cadavers. The LM-PHD selectively stained the articular branches of the cranial gluteal nerve in all but one cadaver. The PPV for LM-PHD successful test prediction was 85.7% (95% confidence interval: 48.6% to 98.6%). Conclusionsand clinical significance Ultrasound-guided LM-PHD using 0.05 mL kg–1 of dye selectively stained the articular branches of the cranial gluteal nerve in canine cadavers. The LM-PHD technique is feasible and could be used as a diagnostic block before acetabular surgical denervation in dogs.

Модель профилактики синдрома профессионального выгорания у педагогических работников

The aim of the study is to develop a holistic methodologically sound model that will allow timely forecasting and managing the process of preventing professional burnout among modern teachers in the context of changing labour activity formats such as online interaction, distant and hybrid learning, emergency self-education and the transition to developing new technologies in digitalizing different aspects of education, etc. Studying the symptoms and phases of school teachers’ professional burnout is carried out, and negative trends associated with a number of factors and causes are identified. The main ones are the following: depersonalization, exhaustion, reduction of professional achievements. The model development is based on a personality-oriented approach and the principles arising from it. The model includes theoretical-target, diagnostic, preventive, reflective-evaluative and advisory blocks. It reflects the relationship of the leading symptoms, phases, causes of burnout with the main areas of preventive work, namely socio-psychological, personal, professional and used technologies. Testing the model shows positive changes in the studied indicators, confirmed by statistically significant differences. This model can be used by school administration staff to predict and manage the process of preventing professional burnout syndrome among teachers.

Anatomical landmarks for ultrasound‐guided rectus femoris diagnostic nerve block in post‐stroke spasticity

AbstractIntroduction/PurposeTo determine the location of the rectus femoris (RF) motor branch nerve, as well as its coordinates with reference to anatomical and ultrasound landmarks.MethodsThirty chronic stroke patients with stiff knee gait (SKG) and RF hyperactivity were included. The motor nerve branch to the RF muscle was identified medially to the vertical line from anterior superior iliac spine and the midpoint of the superior margin of the patella (line AP) and vertically to the horizontal line from the femoral pulse and its intersection point with the line AP (line F). The point of the motor branch (M) was located with ultrasound, and nerve depth and subcutaneous tissue thickness (ST) were calculated.ResultsThe coordinates of the motor branch to the RF were 2.82 (0.47) cm medially to the line AP and 4.61 (0.83) cm vertically to the line F. Nerve depth and subcutaneous tissue thickness were 2.71 (0.62) cm and 1.12 (0.75) cm, respectively.ConclusionThe use of specific coordinates may increase clinicians' confidence when performing RF motor nerve block. This could lead to better decision‐making when assessing SKG in chronic stroke patients.

Effects of Diagnostic Tibial Nerve Block and Selective Tibial Nerve Neurotomy on Spasticity and Spastic co-contractions: A Retrospective Observational Study

Objective: To assess the effects of diagnostic nerve block and selective tibial neurotomy on spasticity and co-contractions in patients with spastic equinovarus foot.Methods: Among 317 patients who underwent a tibial neurotomy between 1997 and 2019, 46 patients who met the inclusion criteria were retrospectively screened. Clinical assessment was made before and after diagnostic nerve block and within 6 months after neurotomy. A total of 24 patients underwent a second assessment beyond 6 months after surgery. Muscle strength, spasticity, angle of catch (XV3), passive (XV1) and active (XVA) ankle range of motion were measured. The spasticity angle X (XV1–XV3) and paresis angle Z (XV1–XVA) were calculated with the knee in flexed and extended positions.Results: Tibialis anterior and triceps surae strength remained unchanged, while both Ashworth and Tardieu scores were highly reduced after nerve block and neurotomy at all measurement times. XV3 and XVA increased significantly after block and neurotomy. XV1 increased slightly after neurotomy. Consequently, spasticity angle X and paresis angle Z decreased after nerve block and neurotomy.Conclusion: Tibial nerve block and neurotomy improve active ankle dorsiflexion, probably by reducing spastic co-contractions. The results also confirmed a long-lasting decrease in spasticity after neurotomy and the predictive value of nerve blocks. LAY ABSTRACTSelective tibial nerve neurotomy is an effective surgical treatment for spastic equinovarus foot deformity after stroke. However, its effectiveness on spastic co-contractions, defined as a disabling involuntary antagonist contraction during an active agonist movement, is unknown. This retrospective study evaluated the effects of tibial neurotomy on the active ankle dorsiflexion limitation related to co- contractions. Selective tibial neurotomy allows an immediate improvement in active dorsal flexion of the ankle, probably by decreasing muscle co-contractions around this joint. This effect continues for the long term for the soleus muscle. This study also confirms that reflex spasticity is permanently reduced after neurotomy. This surgical technique therefore seems useful in limiting impairment caused by the development of spasticity and co-contractions after a stroke.

Cervicogenic headache

IntroductionCervicogenic headache, first proposed as a distinct headache in 1983, is a secondary headache to a primary cervical musculoskeletal disorder. Research into physical impairments was integral to clinical diagnosis and to develop and test research informed conservative management as the first line approach. PurposeThis narrative presents an overview of the body of cervicogenic headache research from our laboratory which was undertaken in the context of a broad program of research into neck pain disorders. ImplicationsEarly research validated manual examination of the upper cervical segments against anaesthetic nerve blocks, which was vital to clinical diagnosis of cervicogenic headache. Further studies identified reduced cervical motion, altered motor control of the neck flexors, reduced strength of flexor and extensor muscles, and occasional presentation of mechanosensitivity of the upper cervical dura. Single measures are variable and not reliable in diagnosis. We proved that a pattern of reduced motion, upper cervical joint signs and impaired deep neck flexor function accurately identified cervicogenic headache and differentiated it from migraine and tension-type headache. The pattern was validated against placebo controlled diagnostic nerve blocks. A large multicentre clinical trial determined that a combined program of manipulative therapy and motor control exercise is effective in the management of cervicogenic headache and outcomes are maintained in the long term.More specific research into cervical related sensorimotor controlled is warranted in cervicogenic headache. Further adequately powered clinical trials of current research informed multimodal programs are advocated to further strengthen the evidence base for conservative management of cervicogenic headache.

A randomised phase II trial of niraparib versus active symptom control in patients with previously treated mesothelioma: NERO.

TPS8600 Background: Malignant mesothelioma is a universally lethal cancer that has been increasing over the last three decades. No treatment has been licenced for patients with relapsed mesothelioma after receipt of licenced systemic anti-cancer therapy in the UK. A previous single-arm phase IIa trial (MiST1) evaluated the efficacy of Poly (ADP-ribose) polymerase (PARP) inhibition in mesothelioma, which met its primary endpoint with 15% of patients having durable responses exceeding 1 year. Therefore, there is a need to evaluate PARP inhibitors in a randomised trial in relapsed mesothelioma patients. NERO is currently in progress in this setting. Methods: Co-ordinated by the CRUK Southampton Clinical Trials Unit, NERO is a multicentre, two arm, open-label UK randomised phase II trial comparing niraparib + Active Symptom Control (ASC) versus ASC alone in mesothelioma patients who have relapsed after previously receiving platinum-based systemic therapy. NERO is not restricted by line of therapy and treatment allocation ratio is 2:1 (niraparib + ASC:ASC), stratified by histology and response to prior platinum-based therapy. Participants will receive either niraparib + ASC or ASC alone for a period of 24 weeks. Participants will be treated until disease progression, withdrawal, death or development of significant treatment limiting toxicity. Participants randomised to niraparib will receive 200/300 mg every day in a 21-day cycle. The primary endpoint is progression-free survival, where progression is determined by modified RECIST or RECIST 1.1; investigator reported progression; or death from any cause, whichever comes first. Time to event data will be analysed and presented using Kaplan-Meier curves according to the intention to treat principle, with treatment-related intercurrent events handled using the treatment strategy policy, and study withdrawal following the “while on study” strategy. A Cox proportional hazards model will be used to calculate the Hazard Ratio, 95% CIs and p-value adjusted for stratification factors. Median PFS and 6 and 12 month PFS will also be reported. Secondary endpoints include overall survival, best overall response, 12 and 24 week disease control, duration of response, treatment compliance and safety/tolerability. Patients consent to provide mandatory diagnostic tissue blocks, blood samples and an optional stool sample for translational research. These will be used to interrogate homologous recombination deficiency and its association with response in NERO, translational research comprising multi-omic analysis with multiplex immune landscape phenotyping will be analysed and correlated with clinical outcome using machine learning. NERO opened in July 2022 and will be run in approximately 10 UK secondary care hospitals with the aim of recruiting 84 evaluable patients (recruitment is currently 24 on 11-Jan-2023). Clinical trial information: NCT05455424 .

17th International Conference on Malignant Lymphoma, Palazzo dei Congressi, Lugano, Switzerland, 13 - 17 June, 2023.

Introduction: R-CHOP remains the standard of care in DLBCL yet for up to 40% of patients (pts.) it fails either through refractory lymphoma or relapse after achieving an initial remission. In the phase Ib/II ACCEPT study (NCT03571308), acalabrutinib (A), a second generation Bruton Tyrosine Kinase inhibitor with enhanced kinase selectivity and a potential for better tolerability, was assessed in combination with R-CHOP in patients with de novo DLBCL. There were no dose-limiting toxicities and the maximum tolerated dose was not reached, At the recommended phase II dose of A 100 mg bd, R-CHOP+A demonstrated a 95% 24 month progression-free survival (PFS). In older patients there was no difference in safety and no compromise of delivery of full course R-CHOP. Efficacy was preserved across cell-of-origin and genomic sub-groups. The REMoDL-A study now builds upon these findings to examine efficacy of R-CHOP+A against R-CHOP. Methods: REMoDL-A is a stratified open-label, multicentre, randomised phase II study. Eligible patients have untreated histologically confirmed DLBCL requiring full course R-CHOP. All patients receive 1 cycle of R-CHOP chemotherapy. FFPE diagnostic pathology blocks have molecular profiling and are assigned subtype Germinal Centre B-cell, Activated B-Cell, Molecular High Grade, Unclassifiable, or failed RNA extraction (GEP Fail). Patients whose biopsies are successfully sub-typed are randomised 2:1 between R-CHOP+A (Arm B) or R-CHOP for a further 5 cycles (Arm A). The randomisation is stratified by molecular subtype, International Prognostic index and age. The primary endpoint for the study is progression free survival (PFS) in the modified intention to treat (ITT) population (non-Fail ITT population). Secondary endpoints include PFS related to the cell of origin and genomic subtypes, duration of response, overall survival, event free survival, toxicity and quality of life. Exploratory analyses will investigate how dynamic molecular (including CTDNA) and PET based biomarkers predict risk and can be incorporated into a dynamic risk prediction model. An early interim analysis is planned to explore safety in the ≥65 years population. The trial is powered to detect a hazard ratio of 0.668 with 90% power with 1-sided significance level of 20%. The number of patients to be randomised is 453 (302:151 per arm). To date 155 patients have been recruited. Of the FFPE diagnostic pathology blocks that have undergone molecular profiling, failed RNA extraction (GEP fail) has occurred in only 4 patients. This is a UK National Cancer Research Institute multicentre trial coordinated by Southampton Clinical Trials Unit. Molecular profiling is performed in HMDS, Leeds. Trial registration: ISRCTN14251143/ NCT04546620 The trial has been supported by an investigator initiated grant and drug access from AstraZeneca (ESR-19-20180) and has endorsement from Cancer Research UK (CRUKE/19/017). Keywords: aggressive B-cell non-Hodgkin lymphoma, combination therapies, ongoing trials Conflicts of interests pertinent to the abstract G. P. Collins Honoraria: Roche, AstraZeneca C. Fox Consultant or advisory role Abbvie, AstraZeneca, Atarabio, BMS, GenMab, Gilead/Kite, Incyte, Lilly, Morphosys, Ono, Roche, Takeda Research funding: Beigene Educational grants: Roche, BMS G. Griffiths Honoraria: AstraZeneca P. Johnson Honoraria: Takeda, InCyte, Genmab, Epizyme A. J. Davies Consultant or advisory role Celgene, Roche, Kite, Takeda, Incyte Honoraria: Celgene, Roche, Kite, Takeda Research funding: Celgene, Roche, Kite, Takeda, Janssen, GSK Educational grants: Celgene, Roche

“Four Legs of a Table”: Building a Stable Foundation and Systematic Approach to Diagnosing Peripheral Nerve Disorders

Management of patients with peripheral nerve disorders is multifaceted and complex; however, it fundamentally hinges upon first correctly localizing the problem. Peripheral nerve disorders may include injury, entrapment, inflammation, tumor, and pain. Differentiating a peripheral nerve condition from one that originates from the spinal or intracranial level is crucial to guiding proper management. A systematic and targeted approach to each patient is required for diagnosis. A comprehensive work-up includes: 1) detailed patient history; 2) thorough physical examination; 3) review of electrodiagnostic studies; and 4) incorporation of diagnostic imaging and (image-guided) diagnostic nerve blocks. Analogous to the “4 legs of a table,” the more findings in each domain that support the same diagnosis, the more certain the diagnosis and more stable the table (Figure 1). We present this framework as a tool for the localization, diagnosis, and treatment of all peripheral nerve issues.

ID: 219222 Peripheral Nerve Stimulation for Refractory Plantar Fibromatosis Pain: A Case Report and Literature Review

41-year-old man was referred by orthopedics to the outpatient pain clinic with history of chronic bilateral plantar heel pain and a diagnosis of plantar fibromatosis following diagnostic ultrasound evaluation. He had failed numerous non-operative treatments including shoe wear modification, orthoses, physical therapy, acupuncture, shock wave therapy, ultrasound guided corticosteroid injection, and percutaneous needle tenotomy. Upon initial consultation, the patient endorsed a 5-year history of bilateral medial plantar heel pain, provoked with weight bearing activities. He denied paresthesias and weakness. Given his refractory symptoms joint the decision was made to proceed with a diagnostic block of his more symptomatic side with goal to pursue bilateral percutaneous 60-day peripheral nerve stimulator placement if he experienced a favorable response. Diagnostic target was the left tibial nerve just proximal to the medial malleolus and prior to its division into plantar and calcaneal branches. Diagnostic injectate consisted of 2cc 1% lidocaine and 5mg of dexamethasone for a total volume of 2.5cc. Patient rated his pain 8/10 prior to injection and 0/10 following. He subsequently underwent placement of dual peripheral nerve stimulators targeting the bilateral tibial nerves with implantation 5cm proximal to the medial malleoli. At 60 day follow up, the device was explanted. The patient was no longer tender with palpation of either foot. He reported 50% reduction compared to pre-operative pain, significant improvement in his quality of life and physical functioning, and a reduction in oral analgesic regimen. The patient is currently awaiting permanent stimulator placement.

Anatomical study of the medial calcaneal nerve using high-resolution ultrasound.

To determine whether high-resolution ultrasound (US) can identify the course and relations of the medial calcaneal nerve (MCN). This investigation was initially undertaken in eight cadaveric specimens and followed by a high-resolution US study in 20 healthy adult volunteers (40 nerves) by two musculoskeletal radiologists in consensus. The location and course of the MCN as well as its relationship to adjacent anatomical structures were evaluated. The MCN was consistently identified by US along its entire course. The mean cross-sectional area of the nerve was 1 mm2 (range 0.5-2). The level at which the MCN branched from the tibial nerve was variable, located a mean of 7mm (range - 7-60) proximal to the tip of the medial malleolus. At the level of the medial retromalleolar fossa, the MCN was located inside the proximal tarsal tunnel a mean of 8mm (range 0-16) posterior to the medial malleolus. More distally, the nerve was depicted in the subcutaneous tissue at the surface of the abductor hallucis fascia with a mean direct distance to the fascia of 1.5mm (range 0.4-2.8). High-resolution US can identify the MCN at the level of the medial retromalleolar fossa, as well as more distally in the subcutaneous tissue at the surface of the abductor hallucis fascia. In the setting of heel pain, precise sonographic mapping of the MCN course may enable the radiologist to make diagnosis of nerve compression or neuroma, and perform selective US-guided treatments. In the setting of heel pain, sonography is an attractive tool for diagnosing compression neuropathy or neuroma of the medial calcaneal nerve, and enables the radiologist to perform selective image-guided treatments such as diagnostic blocks and injections. • The MCN is a small cutaneous nerve which rises from the tibial nerve in the medial retromalleolar fossa to the medial side of the heel. • The MCN can be depicted by high-resolution ultrasound along its entire course. • In the setting of heel pain, precise sonographic mapping of the MCN course may enable the radiologist to make diagnosis of neuroma or nerve entrapment, and perform selective ultrasound-guided treatments such as steroid injection or tarsal tunnel release.

Comparison of the effect of diagnosing discogenic low back pain by sinuvertebral nerve block versus discoblock a retrospective cohort study.

The purpose of this study was to evaluate the efficacy of sinuvertebral nerve blocks in the diagnosis of discogenic low back pain. In this retrospective cohort study, the data of 48 patients with high clinical suspicion of discogenic low back pain from L4/5 who received nerve block treatment from 2017 to 2018 were collected. Twenty-four patients received discoblock (L4/5 intradiscal injection of 1ml 0.5% lidocaine) and another 24 patients received the sinuvertebral nerve block(L4/5 intervertebral space injection of 0.5ml 0.5% lidocaine bilaterally). Percutaneous endoscopic radiofrequency thermal annuloplasty was performed in patients who responded to the diagnostic block. The visual analogue scale scores and Oswestry Disability Index scores in both groups before and 1, 3, and 12months after surgery were compared. Ten patients with a negative diagnostic block did not undergo surgery. Eighteen patients in the discoblock group and 20 patients in the sinuvertebral nerve block group showed a positive response and were evaluated. There were no differences in visual analogue scale or Oswestry Disability Index scores between the two cohorts at baseline or at all time points postsurgery (all p > 0.05). When comparing baseline values to all time points postsurgery improved visual analogue scale scores, and Oswestry Disability Index scores were observed within both cohorts (all p < 0.05). The effect of sinuvertebral nerve block as a diagnostic tool for discogenic low back pain is similar to that of discoblock, and it is a promising tool that deserves further study.

The Peripheral Nerve Surgeon’s Role in the Management of Neuropathic Pain

Summary: Neuropathic pain (NP) underlies significant morbidity and disability worldwide. Although pharmacologic and functional therapies attempt to address this issue, they remain incompletely effective for many patients. Peripheral nerve surgeons have a range of techniques for intervening on NP. The aim of this review is to enable practitioners to identify patients with NP who might benefit from surgical intervention. The workup for NP includes patient history and specific physical examination maneuvers, as well as imaging and diagnostic nerve blocks. Once diagnosed, there is a range of options surgeons can utilize based on specific causes of NP. These techniques include nerve decompression, nerve reconstruction, nerve ablative techniques, and implantable nerve-modulating devices. In addition, there is an emerging role for preoperative involvement of peripheral nerve surgeons for cases known to carry a high risk of inducing postoperative NP. Lastly, we describe the ongoing work that will enable surgeons to expand their armamentarium to better serve patients with NP.