Exploring Symptom Responses to Upper Limb Neural Test Variations of the Radial Nerve in Patients With Lateral Epicondylalgia: An Observational Study.

OBJECTIVE: Clinical practice guidelines recommend the radial nerve mechanosensitivity evaluation in patients with lateral epicondylalgia. Despite different positions and sequences having been described, no research analyzed how each variation triggers symptoms associated with lateral epicondylalgia. The aim of this study was to explore the effects of different positions and sequences in the upper limb neural tension test 2b (ULNT2b) in symptom responses in patients with lateral epicondylalgia. METHODS: In this observational study, 66 patients underwent 4 test conditions: standard ULNT2b, ULNT2b proximal to distal, ULNT2B with resisted supination, and resisted supination isolated. Paresthesia sensations, symptom reproduction, pain intensity (measured using a visual analog scale), and distribution of painful symptoms data were collected. RESULTS: Significant differences in paresthesia sensations were observed between groups, with significant differences between the standard ULNT2B and other ULNT variations or resisted supination maneuvers. Symptom reproduction also differed significantly across groups, with significant differences between the standard ULNT2B and other ULNT or resisted supination tests. The positive/negative test and percentage of distribution of painful symptoms scores varied significantly across 4 conditions in both lateral and frontal views. Although pain intensity scores during tests were comparable among the tests, distribution of painful symptoms differed significantly. CONCLUSION: Variations in the ULNT2b test can affect symptom responses in patients with lateral epicondylalgia. The standard ULNT2b test appears more effective at reproducing symptoms, intensity of paresthesia, and distribution of painful symptoms compared to other ULNT variations and the resisted supination test. IMPACT: ULNT2b sequences have been shown to elicit varying responses concerning paresthesia, replication of familiar symptoms, positive/negative test results, and distribution of painful symptoms. Clinicians should consider specific test variations during the patients' radial nerve mechanosensitivity assessment to identify aggravating factors reproducing recognizable symptoms. A control group of asymptomatic participants and the role of presence of other comorbidities, psychological factors, or the duration of symptoms were not considered in this study and might play an important role influencing the results of the tests.

A Special type of non-traumatic posterior interosseous nerve compression syndrome.

The posterior interosseous nerve (PIN) is the terminal branch of the radial nerve. The symptoms of PIN palsy vary markedly according to its types. In this report, we present the case of a 61-years-old male patient with an unusual manifestation of non-traumatic novel type of PIN palsy. A complicated course was involved in the diagnosis of this disease. The operation was performed after verification of PIN palsy. Recovery of symptoms was observed in a follow-up conducted three years later. Additionally, the electromyography examination returned to normal.

Bi-allelic loss of function variants in COX20 gene cause autosomal recessive sensory neuronopathy.

Sensory neuronopathies are a rare and distinct subgroup of peripheral neuropathies, characterized by degeneration of the dorsal root ganglia neurons. About 50% of sensory neuronopathies are idiopathic and genetic causes remain to be clarified. Through a combination of homozygosity mapping and whole exome sequencing, we linked an autosomal recessive sensory neuronopathy to pathogenic variants in the COX20 gene. We identified eight unrelated families from the eastern Chinese population carrying a founder variant c.41A>G (p.Lys14Arg) within COX20 in either a homozygous or compound heterozygous state. All patients displayed sensory ataxia with a decrease in non-length-dependent sensory potentials. COX20 encodes a key transmembrane protein implicated in the assembly of mitochondrial complex IV. We showed that COX20 variants lead to reduction of COX20 protein in patient's fibroblasts and transfected cell lines, consistent with a loss-of-function mechanism. Knockdown of COX20 expression in ND7/23 sensory neuron cells resulted in complex IV deficiency and perturbed assembly of complex IV, which subsequently compromised cell spare respiratory capacity and reduced cell proliferation under metabolic stress. Consistent with mitochondrial dysfunction in knockdown cells, reduced complex IV assembly, enzyme activity and oxygen consumption rate were also found in patients' fibroblasts. We speculated that the mechanism of COX20 was similar to other causative genes (e.g. SURF1, COX6A1, COA3 and SCO2) for peripheral neuropathies, all of which are functionally important in the structure and assembly of complex IV. Our study identifies a novel causative gene for the autosomal recessive sensory neuronopathy, whose vital function in complex IV and high expression in the proprioceptive sensory neuron further underlines loss of COX20 contributing to mitochondrial bioenergetic dysfunction as a mechanism in peripheral sensory neuron disease.

Post-operative rehabilitation in a traumatic rare radial nerve palsy managed with tendon transfers: a case report.

Radial nerve is a frequently injured nerve. Radial nerve palsy result from direct trauma, neuropathies, and fracture over the humerus, malignant tumor and neuritis. A case of 26-year male is presented in this report who had a road traffic accident resulting in injury over the right shoulder, wrist joint and diagnosed of radial nerve palsy, consequently was operated with soft tissue reconstruction with tendon transfers which resulted into pain over wrist joint and loss of extensors muscle function of the wrist joint, which led to difficulty in performing activities of daily living. Surgical history and rehabilitation is mentioned in the case report. We report that there were significant improvements in muscle strength, range of motion, relief from pain, and exceptional improvements in the patient´s functional independence with physiotherapy interventions post-operative tendon transfers.

Radial motor nerve conduction studies in the upper arm.

INTRODUCTION: The main goal of this study was to determine the contribution of the anterior forearm muscles to the compound muscle action potential (CMAP) recorded from the extensor digitorum (ED) after proximal stimulation. METHODS: Twenty-one healthy volunteers and 114 patients with compressive and traumatic radial neuropathies were examined. Stimulation was carried out at six different points: distal third of the upper arm; Erb's point; axilla; medial upper arm; antecubital fossa; and ulnar groove. RESULTS: In the control group, Erb's CMAP area was significantly greater than the distal CMAP area. In compressive neuropathy, there was conduction block, but no change in conduction velocity. There were no differences in Erb's CMAP latencies between the control group and the neuropathies group. DISCUSSION: CMAPs recorded over the ED with stimulation at the brachial plexus represent the sum of the motor unit action potentials of the posterior and anterior forearm muscles.

Strength-Duration Curves of Radial Nerve in Patients With Lateral Elbow Pain.

CONTEXT: Lateral epicondylalgia (LE) refers to a painful condition at or around the lateral epicondyle of the humerus. LE is one of the most common injuries of the elbow; however, the cause of the pathology is not clear. Patients often experience symptoms consistent with a radial nerve injury; however, data on the involvement of the radial nerve are needed. OBJECTIVE: To analyze the relationship between electrophysiologic excitability and morphology of the radial nerve in patients with unilateral chronic LE. DESIGN: Cross-sectional study. SETTING: Department of Physiotherapy, University of Seville. PATIENTS: A total of 56 elbows (28 right, 28 left) in 28 patients (12 females, 16 males; age 49 [7.37] y) were recruited by convenience sampling. MAIN OUTCOME MEASURES: Strength-duration curves (chronaxia and accommodation index) and cross-sectional area (CSA) of the radial nerve were made in all participants. All parameters were compared between both limbs. Also, pain with palpation in the lateral epicondyle and functional pain of involved extremities was assessed using visual analog scale and the Patient-Rated Tennis Elbow Evaluation, respectively. RESULTS: Symptomatic limb showed higher CSA values of the radial nerve when compared with the asymptomatic limb (P < .001). On the symptomatic limb, duration of symptoms was positively correlated with CSA values. Chronaxia values were all normal and similar between both limbs (P = .35). Regarding accommodation index, 14 (54%) patients showed accommodation indices that suggested pathological radial nerve on the right limb, 4 (14%) on the left limb, 5 (18%) on both limbs, and 4 (14%) had none of the affected nerves. Eight-six percent of patients showed accommodation indices that suggested pathological radial nerve, independently of symptomatic limb. In these cases, affected nerves had higher CSA than the unaffected nerve (P = .01). On the affected nerves, duration of symptoms was positively correlated with accommodation indices. CONCLUSIONS: These findings suggest that patients with unilateral chronic LE show a decreased excitability in any radial nerve, independently of the symptomatic limb, and that pathological nerves have higher CSA than the nonpathological nerves.

Polyneuropathy and the sural/radial sensory nerve action potential ratio in primary Sjögren's syndrome.

Objectives: Polyneuropathy is the most common neurological complication in primary Sjögren's syndrome (pSS). A ratio of sural nerve and superficial radial nerve sensorial action potential amplitudes (SRARs) of <0.4 is an indicator for early axonal neuropathy. We evaluated the polyneuropathies and SRARs in pSS patients.Method: Fifty-two female patients who were diagnosed with pSS according to the European-American Consensus Criteria and 45 healthy controls were enrolled. Nerve conduction studies were performed to diagnose polyneuropathy. Sensory axonal polyneuropathy was diagnosed in three patients, so SRARs were compared in 49 patients and 50 healthy controls.Results: Fifty-two patients with pSS underwent nerve conduction tests. The sural sensory nerve action potential (SNAP) was <6 µV in threepatients and they were diagnosed with sensory axonal neuropathy. SRARs were evaluated in 49 female patients, with a mean age of 51.98 ± 10.79 years and 50 healthy controls with a mean age of 50.52 ± 12.55 years. The mean disease duration was 7.59 ± 6.17 years. The SRAR values were different between the patient and control groups. SRAR was <0.4 in 20.4% of the patient group and <0.4 in 6% of the control group. The SRAR value was not statistically different within the patient group based on anti-Ro and anti-La.Discussion: The potential for neurological involvement in patients with pSS who have no signs or injury should be evaluated because nervous system involvement in pSS is a negative prognostic factor. SRAR in patients with pSS can be used as a marker for the early detection of axonal neuropathy.

Spontaneous Radial Nerve Palsy due to an Unrecognized Myofibroma: A Case Report.

CASE: A 33-year-old woman presented with a six-month history of spontaneous radial nerve palsy and no identified lesion on imaging. She underwent operative exploration where an hourglass deformity was seen and resected. Pathology returned as a rare tumor, a myofibroma. The patient regained full radial nerve function. CONCLUSIONS: A trial of observation is often indicated in the cases of isolated nerve palsy where anatomic lesions have been eliminated. This case highlights that imaging studies can miss a tumor involving nerve and that painless, spontaneous nerve palsy may be a time where early surgical intervention offers a better chance of recovery.

A method of ultrasound diagnosis for unilateral peripheral entrapment neuropathy based on multilevel side-to-side image contrast.

Individual variations have been reported in the existing methods for examining peripheral entrapment neuropathy, by which limited sites can be examined. In this study, the patients with unilateral carpal tunnel syndrome (CTS), cubital tunnel syndrome (CuTS) and radial nerve compression (RNC) were selected as research subjects and an ultrasound technique was proposed based on multilevel side-to-side image contrast for the diagnosis of unilateral peripheral entrapment neuropathy. According to the statistical analysis of 62 patients with CTS, CuTS or RNC, the diagnostic thresholds of the cross-sectional area swelling ratio (CSASR) for diagnosis of CTS, CuTS or RNC were 1.22, 1.51 and 1.50, respectively. The surgical therapeutic thresholds of CSASR for the treatment of CTS, CuTS and RNC were 1.48, 1.67 and 3.04, respectively. When the maximal CSASR of the diseased nerve was greater than or equal to the diagnostic threshold, the nerve compression could be diagnosed. If it was less than the diagnostic threshold, nerve compression was excluded. Conservative treatment was indicated when the maximal CSASR of the diseased nerve was less than the therapeutic threshold. When the maximal CSASR was greater than or equal to the therapeutic threshold, surgical treatment was indicated, and the nerve release procedure was selected. The novel multilevel side-to-side image contrast ultrasound technique proposed in this study can substantially reduce the impact of individual variation and explore the full course of the diseased nerve. It is a novel approach for diagnosis, treatment selection, and determination of treatment sites of unilateral peripheral entrapment neuropathy.

Electrophysiological determinants of the clinical severity of axonal peripheral neuropathy.

INTRODUCTION: Electrophysiological diagnosis of axonal peripheral neuropathy (PN) is based on the attenuated amplitudes of nerve conduction studies (NCS), or a reduced sural/radial amplitude ratio (SRAR). We aimed to identify the electrophysiological determinants of the clinical severity of PN. METHODS: Patients with chronic axonal PN underwent detailed NCS. The clinical severity of PN was determined based upon the overall neuropathy limitations scale (ONLS). RESULTS: Ninety-five patients (71.6% males, mean age 71.9 ± 9.0 years) were recruited. Significant correlations were observed between the radial sensory nerve action potential (SNAP) and the ONLS total score (Spearman's rho -0.382, p < 0.001); and between the tibial compound muscle action potential and the ONLS leg score (Spearman's rho -0.283, p = 0.005). No correlations between the SRAR and the ONLS scores were found. DISCUSSION: The radial SNAP is the strongest electrophysiological determinant of PN severity and might be useful for monitoring disease progression or response to treatment. Muscle Nerve 59:491-493, 2019.

Ultrasound-Guided Percutaneous Electrical Nerve Stimulation of the Radial Nerve for a Patient With Lateral Elbow Pain: A Case Report With a 2-Year Follow-up.

BACKGROUND: Patients with lateral elbow pain are often diagnosed with lateral epicondylalgia. Lateral elbow pain is often associated with dysfunction of the wrist extensor muscles; however, in some cases, it can also mimic signs and symptoms of radial nerve dysfunction. CASE DESCRIPTION: In this case report, a 43-year-old man, who was originally referred with a diagnosis of lateral epicondylalgia as a result of playing table tennis and who previously responded favorably to manual therapy and exercise, presented to the clinic for treatment. An exacerbation while participating in a table tennis match resulted in a return of his lateral epicondylalgia symptoms, which did not respond favorably to the same interventions used in his prior course of therapy. Further examination revealed sensitization of the radial nerve, which was treated with 2 sessions of ultrasound-guided percutaneous electrical nerve stimulation and 4 weeks of a low-load, concentric/eccentric exercise program for the wrist extensors. OUTCOMES: Following this intervention, the patient experienced clinically meaningful improvement in pain intensity (numeric pain-rating scale), function (Patient-Rated Tennis Elbow Evaluation), and related disability (Disabilities of the Arm, Shoulder and Hand questionnaire). The patient progressively exhibited complete resolution of pain and function, which was maintained at 2 years. DISCUSSION: This case report demonstrates the outcomes of a patient with lateral elbow pain who did not respond to manual therapy and exercise. Once radial nerve trunk sensitivity was identified and the intervention, consisting of ultrasound-guided percutaneous electrical nerve stimulation targeting the radial nerve combined with a low-load exercise program, was applied, a full resolution of pain and function occurred rapidly. Future clinical trials should examine the effect of percutaneous electrical nerve stimulation in the management of nerve-related symptoms associated with musculoskeletal pain conditions. LEVEL OF EVIDENCE: Therapy, level 5. J Orthop Sports Phys Ther 2019;49(5):347-354. Epub 18 Jan 2019. doi:10.2519/jospt.2019.8570.

Diffusion tensor imaging in anterior interosseous nerve syndrome - functional MR Neurography on a fascicular level.

PURPOSE: By applying diffusor tensor imaging (DTI) in patients with anterior interosseous nerve syndrome (AINS), this proof of principle study aims to quantify the extent of structural damage of a peripheral nerve at the anatomical level of individual fascicles. METHODS: In this institutional review board approved prospective study 13 patients with spontaneous AINS were examined at 3 Tesla including a transversal T2-weighted turbo-spin-echo and a spin-echo echo-planar-imaging pulse sequence of the upper arm level. Calculations of quantitative DTI parameters including fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD), and axial diffusivity (AD) for median nerve lesion and non-lesion fascicles as well as ulnar and radial nerve were obtained. DTI values were compared to each other and to a previously published dataset of 58 healthy controls using one-way Analysis of Variance with Bonferroni correction and p-values <.05 were considered significant. Receiver operating characteristic (ROC) curves were performed to assess diagnostic accuracy. RESULTS: FA of median nerve lesion fascicles was decreased compared to median nerve non-lesion fascicles, ulnar nerve and radial nerve while MD, RD, and AD was increased (p < .001 for all parameters). Compared to median nerve values of healthy controls, lesion fascicles showed a significant decrease in FA while MD, RD, and AD was increased (p < .001 for all parameters). FA of median nerve non-lesion fascicles showed a weak significant decrease compared to healthy controls (p < .01) while there was no difference in MD, RD, and AD. ROC analyses revealed an excellent diagnostic accuracy of FA, MD and RD in the discrimination of median nerve lesion and non-lesion fascicles in AINS patients as well as in the discrimination of lesion fascicles and normative median nerve values of healthy controls. CONCLUSION: By applying this functional MR Neurography technique in patients with AINS, this proof of principle study demonstrates that diffusion tensor imaging is feasible to quantify structural nerve injury at the anatomical level of individual fascicles.

A Pilot Study of a Novel Automated Somatosensory Evoked Potential (SSEP) Monitoring Device for Detection and Prevention of Intraoperative Peripheral Nerve Injury in Total Shoulder Arthroplasty Surgery.

INTRODUCTION: Peripheral nerve injury is a potentially devastating complication after total shoulder arthroplasty (TSA) surgery. This pilot study aimed to assess the feasibility of using an automated somatosensory evoked potential (SSEP) device to provide a timely alert/intervention to minimize intraoperative nerve insults during TSA surgery. METHODS: A prospective, single-arm, observational study was conducted in a single university hospital. The attending anesthesiologist monitored the study participants using the EPAD automated SSEP device and an intervention was made if there was an alert during TSA surgery. The median, radial, and ulnar nerve SSEP on the operative arm, as well as the median nerve SSEP of the nonoperative arm were monitored for each patient. All patients were evaluated for postoperative neurological deficits 6 weeks postoperatively. RESULTS: In total, 21 patients were consented and were successfully monitored. In total, 4 (19%) patients developed intraoperative abnormal SSEP signal changes in the operative arm, in which 3 were reversible and 1 was irreversible till the end of surgery. Median and radial nerves were mostly involved (3/4 patients). The mean cumulative duration of nerve insult (abnormal SSEP) was 21.7±26.2 minutes. Univariate analysis did not identify predictor of intraoperative nerve insults. No patients demonstrated postoperative peripheral neuropathy at 6 weeks. CONCLUSIONS: A high incidence (19%) of intraoperative nerve insult was observed in this study demonstrating the feasibility of using an automated SSEP device to provide a timely alert and enable an intervention in order to minimize peripheral nerve injury during TSA. Further randomized studies are warranted.

Effect of dry needling on radial tunnel syndrome: A case report.

This case report describes a 45-year-old male who presented with chronic right lateral elbow pain managed unsuccessfully with conservative treatment that included anti-inflammatory medication, injection, massage, exercise, bracing, taping, electro-physical agents, and manual therapy. Diagnosis of radial tunnel syndrome (RTS) was based on palpatory findings, range of motion testing, resisted isometrics, and a positive upper limb neural tension test 2b (radial nerve bias). Conventionally, the intervention for this entrapment has been surgical decompression, with successful outcomes. This is potentially a first-time report, describing the successful management of RTS with dry needling (DN) using a recently published DN grading system. Immediate improvements were noted in all the outcome measures after the first treatment, with complete pain-resolution maintained at a 6-month follow-up. A model is proposed describing the mechanism by which DN could be used to intervene for nerve entrapment interfaces.

Anterior humeral approach with nerve stimulator.

INTRODUCTION: The prevalence of radial nerve injury during surgery is as high as the prevalence of radial nerve injury due to trauma. The aim of this study is to minimize the risk of iatrogenic injury of radial nerve. MATERIALS AND METHODS: Fifty patients with middle or distal diaphysis fractures of humerus and 18 patients with pseudoarthrosis at the same localizations were treated with surgery. Plate-screw fixation was performed with anterior approach in 43 patients. Eleven patients had minimally invasive plate osteosynthesis, and 14 patients had intramedullary nailing. The localization of the radial nerve was determined with nerve stimulator at the area of dissection. RESULTS: Iatrogenic radial nerve injury did not occur in patients treated with open reduction or minimally invasive approach. DISCUSSION: Nerve stimulator may be a method that decreases radial nerve injury, an iatrogenic complication. This method may be used in anterior approach and minimally invasive procedures.

Double-Shock Stimulation of the Superficial Radial Nerve Compared With Standard Medial Plantar Nerve Conduction in the Early Detection of Asymptomatic Diabetic Neuropathy: A Pilot Study.

PURPOSE: Diabetes mellitus is a major public health problem. Diabetic polyneuropathy (DP) is one of the most common complications of diabetes mellitus. The early detection of DP is very important for timely treatment of symptoms and preventative foot care. METHODS: Participants were sorted into 3 age- and sex-matched groups: 20 "healthy" individuals; 21 diabetic patients without DP symptoms, "asymptomatic"; and 24 diabetic patients suffering from symptoms consistent with DP, "symptomatic." All study participants had normal results on conventional nerve conduction studies. All groups underwent both medial plantar mixed nerve conduction (as a single-shock stimulation technique) and superficial radial nerve conduction (double-shock stimulation) measurements. Interstimulus intervals of 2 to 8 ms were used to record sensory nerve action potentials (SNAP) 1 and SNAP 2 for both stimuli. RESULTS: We found statistically significant decreases in medial plantar NAPs' amplitude and conduction velocity, and SNAP1/SNAP2 ratios between the three groups, especially at smaller interstimulus intervals. CONCLUSIONS: Both medial plantar mixed nerve conduction and double-shock superficial radial nerve stimulation are reliable methods for the early detection of asymptomatic DP. However, the medial plantar mixed nerve technique is easier and less time-consuming.

Incidence and Clinical Course of Limb Dysfunction Post Cardiac Catheterization　- A Systematic Review.

BACKGROUND: We systematically reviewed the available literature on limb dysfunction after transradial access (TRA) or transfemoral access (TFA) cardiac catheterization. Methods and Results: MEDLINE and EMBASE were searched for studies evaluating any transradial or transfemoral procedures and limb function outcomes. Data were extracted and results were narratively synthesized with similar treatment arms. The TRA group included 15 studies with 3,616 participants and of these 3 reported nerve damage with a combined incidence of 0.16% and 4 reported sensory loss, tingling and numbness with a pooled incidence of 1.61%. Pain after TRA was the most common form of limb dysfunction (7.77%) reported in 3 studies. The incidence of hand dysfunction defined as disability, grip strength change, power loss or neuropathy was low at 0.49%. Although radial artery occlusion (RAO) was not a primary endpoint for this review, it was observed in 3.57% of the participants in a total of 8 studies included. The TFA group included 4 studies with 15,903,894 participants; the rates of peripheral neuropathy were 0.004%, sensory neuropathy caused by local groin injury and retroperitoneal hematomas were 0.04% and 0.17%, respectively, and motor deficit caused by femoral and obturator nerve damage was 0.13%. CONCLUSIONS: Limb dysfunction post cardiac catheterization is rare, but patients may have nonspecific sensory and motor complaints that resolve over a period of time.