Search Results (104)

Background: Hand–arm vibration syndrome (HAVS) is a well-recognized occupational condition resulting from prolonged exposure to hand-transmitted vibration (HTV), characterized by vascular, neurological, and musculoskeletal impairments. While vibration exposure is a known risk factor for HAVS, less is understood about the role of personal risk factors and, particularly regarding neurosensory dysfunction. This study aimed to examine the association between vibrotactile (VPT) and thermotactile perception thresholds (TPT) and individual risk factors and comorbidities in HTV-exposed workers. Methods: A total of 235 male HTV workers were evaluated between 1995 and 2005 at the University of Trieste’s Occupational Medicine Unit. Personal, occupational, and health-related data were collected, and sensory function was assessed in both hands. VPTs at 31.5 and 125 Hz and TPTs (for warm and cold) were measured on fingers innervated by the median and ulnar nerves. Results: Multivariable regression analysis revealed that impaired VPTs were significantly associated with age, higher daily vibration exposure (expressed as 8 h energy-equivalent A(8) values), BMI ≥ 25, smoking, vascular/metabolic disorders, and neurosensory symptoms. In contrast, TPTs showed weaker and less consistent associations, with some links to smoking and alcohol use. Conclusions: These findings suggest that, in addition to vibration exposure, individual factors such as aging, overweight, smoking, and underlying health conditions significantly contribute to neurosensory impairment and may exacerbate neurosensory dysfunction in a context of HAVS. The results underscore the importance of including personal health risk factors in both clinical assessment and preventive strategies for HAVS and may inform future research on its pathogenesis. Full article

Background: Cubital tunnel syndrome is the second most common compressive neuropathy of the upper limb, and it is characterized by ulnar nerve compression at the elbow. Traditional surgical options, including simple decompression and anterior transposition, have limitations in addressing ulnar nerve instability. This study introduces and evaluates the short-term outcomes of a novel surgical technique, the fascio-aponeurotic epicondylar flap (FAEF), for stabilizing the ulnar nerve and managing its instability. Materials and methods: A retrospective study was conducted on ten patients with longstanding cubital tunnel syndrome and confirmed ulnar nerve dislocation or instability. All patients underwent surgical intervention using the FAEF technique, which involves creating a quadrangular fascial flap from the epicondylar fascia to stabilize the ulnar nerve within the retrocondylar groove. Outcomes were assessed using clinical follow-ups, the Michigan Hand Outcomes Questionnaire (MHQ), VAS, and qDASH scores over a 90-day postoperative period. Results: All ten patients experienced complete resolution of neurological symptoms, including paresthesia, pain, and nerve clicking, by the final follow-up. Postoperative recovery was uneventful, with no complications such as infections or hematomas. Grip strength and hand functionality were fully restored, with significant improvements in MHQ scores (mean: 94). Dynamic elbow mobilization initiated on the first postoperative day resulted in full recovery of elbow range of motion. No recurrence of ulnar nerve dislocation was observed. Discussion: The FAEF technique effectively stabilizes the ulnar nerve, alleviates symptoms, and restores function while minimizing risks associated with traditional procedures, such as nerve trauma and elbow instability. By preserving the anatomical integrity of the medial epicondyle and enhancing nerve mobility, this approach represents a less invasive alternative to anterior transposition and medial epicondylectomy. Conclusions: The FAEF technique is a viable and effective surgical option for managing ulnar nerve instability in cubital tunnel syndrome. It offers a less invasive solution with excellent short-term outcomes, making it a promising addition to the surgical armamentarium for this condition. Further studies are warranted to evaluate long-term efficacy and broader applicability. Full article

Background/Objectives: The Wartenberg sign is a diagnostic feature of ulnar nerve neuropathy. It results from unbalanced activity of the abductor digiti minimi (ADM) and extensor digiti minimi (EDM) muscles secondary to weakness of the third palmar interosseous muscle. Rarely, this sign may occur in the absence of an underlying ulnar neuropathy, which we refer to as the “pseudo Wartenberg sign” (PWS). Methods: This is a retrospective review of 10 patients manifesting an inability to adduct the little finger towards the ring finger with no evidence of an ulnar neuropathy. We describe the clinical and electrodiagnostic (EDX) findings in these patients and discuss the pathophysiologic basis of PWS. Results: The most common cause was an injury in five (50.0%) patients: avulsion of the third volar interosseous muscle in two (20.0%), contracture of the ADM muscle in one (10.0%), and trauma-related dystonia in two (20.0%). The most frequent mechanism of PWS was focal dystonia of specific hand muscles in seven (70.0%) patients. Needle electromyography (EMG) demonstrated no denervation changes in ulnar nerve-innervated hand muscles; the motor and sensory conduction was normal in the ulnar nerve in all patients. Four (40.0%) patients underwent ultrasound studies, with a hyperechoic, avulsed third volar interosseous muscle in one, a hyperechoic and atrophic ADM muscle in one, normal hypothenar and extensor muscles in one, and a normal hypothenar muscle in one. Conclusions: Neurologists, neurosurgeons, and hand and orthopedic surgeons should be aware of the rare cases in which the inability to adduct the little finger may occur in the absence of ulnar neuropathy and look for other causes like avulsion of the third palmar interosseus muscle or focal hand dystonia. Full article

Introduction: Carpal Tunnel Syndrome (CTS) is a prevalent neuropathy requiring accurate, non-invasive diagnostics to minimize patient burden. This study evaluates the New Energy Vision (NEV) camera, an RGB-based multispectral imaging tool, to detect CTS through skin texture and color analysis, developing a machine learning algorithm to distinguish CTS-affected hands from controls. Methods: A two-part observational study included 103 participants (50 controls, 53 CTS patients) in Part 1, using NEV camera images to train a Support Vector Machine (SVM) classifier. Part 2 compared median nerve-damaged (MED) and ulnar nerve-normal (ULN) palm areas in 32 CTS patients. Validations included nerve conduction tests (NCT), Semmes–Weinstein monofilament testing (SWMT), and Boston Carpal Tunnel Questionnaire (BCTQ). Results: The SVM classifier achieved 93.33% accuracy (confusion matrix: [[14, 1], [1, 14]]), with 81.79% cross-validation accuracy. Part 2 identified significant differences (p < 0.05) in color proportions (e.g., red_proportion) and Haralick texture features between MED and ULN areas, corroborated by BCTQ and SWMT. Conclusions: The NEV camera, leveraging multispectral imaging, offers a promising non-invasive CTS diagnostic tool using detection of nerve-related skin changes. Further validation is needed for clinical adoption. Full article

Background: Amyotrophic Lateral Sclerosis (ALS) is a neurodegenerative disease that leads to nerve atrophy. Ultrasonography has a significant role in the diagnosis of ALS. Aim: We aimed to sonographically assess the size of all peripheral nerves and cervical nerve roots in ALS compared to controls. Methods: We searched MEDLINE (PubMed), Web of Science, Cochrane Central Register of Controlled Trials (CENTRAL), Embase, and Scopus using comprehensive MeSH terms for the keywords nerve, ultrasound, and ALS. We extracted data regarding cross-sectional area (CSA) or diameter for the following nerves: vagus, phrenic, tibial, fibular, sural, radial, ulnar, and median nerves, and the roots of C5, C6, C7, and C8 in both ALS patients and controls. Results: Our study included 2683 participants, of which 1631 were ALS patients (mean age = 60.36), 792 were healthy controls (mean age = 57.79), and 260 were patients with other neurological disorders. ALS patients had significantly smaller nerve size compared to controls. Nerve size differences were observed in the vagus nerve [MD = −0.23], phrenic nerve [MD = −0.25], C5 nerve root [SMD = −0.94], C6 nerve root [SMD = −1.56], C7 nerve root [SMD = −1.18], C8 nerve root [MD = −1.9], accessory nerve [MD = −0.32], sciatic nerve [MD = −11], tibial nerve [MD = −0.68], sural nerve [MD = −0.32,], ulnar nerve [MD = −0.80], and median nerve [MD = −1.21]. Conclusions: Our findings showed that ALS patients have a sonographically smaller nerve size than healthy controls. Therefore, this is a potential marker for neuronal diseases. Full article

Since its discovery, TRPC6 has been associated with a variety of physiological and pathophysiological processes in different tissues. It functions as a non-selective cation channel and belongs to the group of TRP channels. Its importance in the development of pain hypersensitivity is becoming increasingly apparent. This condition has already been associated with increased expression of TRPC6 in dorsal root ganglia. Apart from the fact that most of the evidence has been obtained from samples of animal origin, it remains unclear whether the channel is also expressed in peripheral nerves outside the dorsal root ganglia. The aim of this work was therefore to examine peripheral nerves from human samples for TRPC6. For this purpose, samples of both the sciatic and ulnar nerves were taken from a total of eight body donors and analyzed by immunohistochemistry. Both longitudinal and transverse sections were obtained from the samples and stained. In total, 43 of 48 histological sections showed a positive immunosignal. There were no major differences between the sciatic and ulnar nerves with regard to staining. There was a slight difference in the staining intensity of transverse and longitudinal sections. The longitudinal sections of both nerves were consistently colored slightly more intensely. However, the inter-individual differences between the donors were more pronounced. Interestingly, the samples of a donor who suffered from chronic pain syndrome during his lifetime were particularly strongly stained. This is consistent with the knowledge gained to date, largely from animal experiments, that the channel shows increased expression in pain conditions in dorsal root ganglia. In the future, TRPC6 could therefore be a target in pain therapy. Full article

Background: The brachial plexus is a network of nerves responsible for the motor and sensory innervation of the upper limb. Variations in the formation and course of the brachial plexus are well documented, though combinations of multiple unilateral abnormalities are rare. The complex pathology of this structure nerve may result in clinical consequences. We present a unique set of brachial plexus abnormalities involving the C4–C6 nerve roots, superior and middle trunks, additional communicating branches, and delayed median nerve union. Case Presentation: During the routine dissection of a 70-year-old female cadaver, several unique variations in the brachial plexus anatomy were identified. The C4 root contributed to C5 before the superior trunk formed, resulting in a superior trunk composed of C4–C6. The C5 root was located anterior to the anterior scalene muscle, whereas C6 maintained its usual posterior position. Additionally, an anterior communicating branch from the middle trunk to the posterior cord was observed. A communicating branch between the lateral and medial cords split into two terminal branches: one merged with the ulnar nerve, and the other joined the medial contribution of the median nerve. The median nerve contributions from the lateral and medial cords merged approximately two inches above the elbow. Conclusions: This rare combination of brachial plexus anomalies has not been previously described in the literature and is of significant clinical relevance. The additional anterior communicating branch from the middle trunk may suggest potential flexor muscle innervation by the posterior cord, which typically innervates extensor muscles. Additionally, the delayed convergence of the median nerve may provide a protective mechanism in cases of midshaft humeral fracture. Awareness of these peripheral nerve abnormalities is important for diagnostic imaging, surgery, or peripheral nerve blocks. Knowledge of such variations is critical for clinicians managing upper limb pathologies. Full article

Supracondylar humeral fractures are the most common type of elbow fractures in children. The treatment methods vary depending on the type of fracture (Gartland classification), which can be conservative or surgical. There is no clear consensus or guidelines to dictate the treatment of complicated supracondylar humeral fractures (Gartland types II and III). Gartland type II and III fractures are most frequently treated with closed reduction and percutaneous Kirchner-wire pinning or open reduction with K-wire pinning, depending on the degree of displacement and the orthopedic surgeon’s preference. Most studies recommend avoiding open reduction because of prolonged hospitalization and higher rates of complications. Orthopedic surgeons have different opinions regarding the Kirschner pin placement technique. Studies suggest that only lateral pinning is safe and effective, but medial and lateral pinning is proven to give more stability; there is always a risk of iatrogenic ulnar nerve damage during surgery. Modern treatment of supracondylar humeral fracture in children should focus on minimally invasive techniques and avoid open reduction, when possible, to ensure the best outcome for the patients. This scoping review’s purpose is to gather the available information on the topic in one place and to underline the lack of clear protocols. Full article

Peripheral nerve blocks play a critical role in pain management; however, no technique has been described to specifically target the articular nerve branches of the elbow in dogs. This study aimed to develop and compare the success rate of an ultrasound-guided versus a blind pericapsular elbow desensitization (PED) technique in canine cadavers. Phase I involved gross and ultrasonographic evaluations of the elbow joint in four cadavers to identify landmarks for the PED technique. Phase II compared the ultrasound-guided and blind PED techniques using dye injections in eight cadavers, followed by the dissection and histological analysis of stained tissues to confirm nerve involvement. The results demonstrated that four quadrant injections are required to target the articular branches of the radial, ulnar, median, and musculocutaneous nerves. The ultrasound-guided technique achieved a significantly higher overall success rate (77.5%) than the blind technique (45%, p = 0.005). While both techniques showed similar success rates (50–62.5%) for the ulnar, median, and musculocutaneous branches, the ultrasound-guided technique (100%) outperformed the blind technique for the cranial (37%, p = 0.02) and caudal (12.5%, p = 0.001) articular branches of the radial nerve. These findings provide a foundation for future clinical studies evaluating the ultrasound-guided PED technique in live animals. Full article

Postoperative ulnar neuropathy is a common complication in patients undergoing surgery for distal humerus fractures, particularly when open reduction and internal fixation (ORIF) is performed. Objectives: This study aims to compare the rates of ulnar nerve neuropathy following classic in situ decompression versus ulnar nerve subcutaneous anterior transposition. Methods: A retrospective study was conducted, including 51 patients treated for distal humerus fractures with precontoured locking plates in our institution between 2009 and 2023, according to specific inclusion and exclusion criteria. Age, sex, ulnar neuropathy, range of motion (ROM), complications, surgical approach, and Mayo Elbow Performance Score (MEPS) were evaluated. Ulnar nerve function was graded according to modified McGowan classification. Results: Ulnar neuropathy was observed in 17 (33.3%) patients, with a higher risk in those who underwent anterior ulnar nerve transposition compared to in situ decompression (58% vs. 26%, p = 0.042). In the modified McGowan classification, 14 patients had grade 1 and 3 had grade 2 neuropathy. The overall complication rate was 49%, and the functional outcomes according to the MEPS scale showed a mean score of 81.6 (SD 17.29). The mean flexion–extension was 100.56°, and 94% of patients retained complete pronosupination. Conclusions: Our results demonstrate that routine intraoperative ulnar nerve transposition should not be performed for these fractures. Full article

Background/Objective: To assess the effectiveness of therapy based on sliding and tensioning neurodynamic techniques in the conservative treatment of mild and moderate forms of cubital tunnel syndrome (CuTS) compared to sham therapy. Methods: A single-blinded, randomized placebo-controlled trial. The study was conducted at several medical clinics. Individuals diagnosed with CuTS (initially 136 subjects, of whom 91 completed the full protocol) participated in the experiment. In the experimental group (MT), sliding and tensioning neurodynamic techniques were applied, whereas in the control group (ST), a sham therapy was used, involving the performance of neurodynamic techniques in an intermediate position without following the specific neurodynamic sequence for the ulnar nerve. The therapy was administered five times per week over the course of 10 sessions. All participants underwent assessments, including nerve conduction studies, ultrasound imaging (cross-sectional area and shear modulus), pain levels, two-point discrimination sensation, cutaneous sensory perception threshold, symptoms, ability to perform certain activities, and changes in improvement following treatment. Results: A baseline assessment revealed no significant inter-group differences in all examined parameters (p > 0.05). After therapy, there was a statistically significant intra-group improvement in all parameters tested (p < 0.01). In the MT group, the intra-group differences were significant across all parameters tested (p < 0.01). However, in the ST group (sham therapy), only the shear modulus showed statistically significant changes, while the other tested parameters remained unchanged. Conclusions: Neurodynamic techniques demonstrate superior therapeutic effects compared to sham therapy in the treatment of mild to moderate forms of CuTS. Full article

Guyon’s canal, or the ulnar tunnel, is a critical anatomical structure at the wrist that houses the ulnar nerve and artery, making it susceptible to various pathological conditions. Pathologies affecting this canal include traumatic injuries, compressive neuropathies like ulnar tunnel syndrome, and space-occupying lesions such as ganglion cysts. Ulnar tunnel syndrome, characterised by numbness, tingling, and weakness in the ulnar nerve distribution, is a prevalent condition that can severely impair hand function. The canal’s intricate anatomy is defined by surrounding ligaments and bones, divided into three zones, each containing distinct neural structures. Variations, including aberrant muscles and vascular anomalies, can complicate diagnosis and treatment. Imaging techniques are essential for evaluating these conditions; ultrasound provides real-time, dynamic assessments, while magnetic resonance imaging (MRI) offers detailed visualisation of soft tissues and bony structures, aiding in pre-surgical documentation and pathology evaluation. This review article explores the anatomy, pathologies, and imaging modalities associated with Guyon’s canal and underscores the necessity of understanding Guyon’s canal’s anatomy and associated pathologies to improve diagnostic accuracy and management strategies. By integrating anatomical insights with advanced imaging techniques, clinicians can enhance patient outcomes and preserve hand function, emphasising the need for increased awareness and research in this often-neglected area of hand anatomy. Full article

The medial approach is a traditional portal during elbow arthroscopy. Some researchers have suggested that the caudo-medial arthroscopic approach allows better visualization of the medial and caudal elbow compartments. Such a portal is created caudally to the medial humeral epicondyle’s caudal aspect in the ulnar nerve’s vicinity. Therefore, we investigated the risk of ulnar nerve injury following the caudo-medial portal placement in 30 canine cadavers. After the telescope was inserted, an incision was made to visualize the nerve, and the distance between the cannula and the nerve was measured. An injury was diagnosed when the telescope at least scratched the nerve. The distance between the arthroscopic cannula and the ulnar nerve ranged from 0 to 8.0 mm (median: 0.5 mm) in 60 joints. Nerve injury occurred in 16/30 dogs (53%; CI 95%: 36%, 70%)—in 11 unilaterally and 5 bilaterally. In addition, in eight dogs, the cannula directly touched the nerve, creating a high risk of trauma. In total, nerve injury or high risk of trauma occurred in 21/30 dogs (70%; CI 95%: 52%, 83%). Ulnar nerve injury during caudo-medial arthroscopic portal creation appears common. Full article

This prospective, experimental, randomised, assessor-blinded cadaveric study was undertaken to describe the sono-anatomical features of the radial, ulnar, median and musculocutaneous (RUMM) nerves in rabbits and to develop and evaluate an ultrasound (US)-guided proximal RUMM block technique comparing a medial versus a lateral approach. A total of 13 adult rabbit cadavers were used. In Phase I of the study, four cadavers were used for anatomical dissection and to design and test a lateral and medial single injection point US-guided proximal RUMM block technique, while in Phase II, the medial and lateral approaches were randomly performed on nine cadavers administering 0.1 mL kg⁻¹ injectate. After dissection, nerve staining was categorised as adequate (all nerves stained ≥4 mm) or inadequate (at least one nerve not stained or stained <4 mm). Staining spread was compared with Fisher’s exact test, with p < 0.05 considered statistically significant. From Phase I, the axillary fascia containing all RUMM nerves was identified. The radial nerve exited the fascia right after the humeral head. In the lateral approach, the transducer was angled at 80° to the humerus longitudinal axis. In the medial approach, the transducer was placed perpendicularly to the humerus longitudinal axis. In both approaches, the brachial artery appeared as a rounded and anechoic structure, the musculocutaneous nerve as hypoechoic and oval and the radial nerve as a honeycomb, and the ulnar and median nerves were identified adjacent to each other. The radial nerve was selected as the injection point for both approaches using an in-plane technique. In Phase II, the injectate was found outside the axillary fascia in zero out of nine and five out of nine thoracic limbs, with an adequate staining in nine of nine and two of nine injections (p < 0.01) using the medial and lateral approach, respectively. Thus, a US-guided proximal RUMM block technique is feasible in rabbits, and the medial approach demonstrated evidence of a more consistent stain of the RUMM nerves. Full article

CXCL12 and CXCR4 proteins and mRNAs were monitored in the dorsal root ganglia (DRGs) of lumbar (L4–L5) and cervical (C7–C8) spinal segments of naïve rats, rats subjected to sham operation, and those undergoing unilateral complete sciatic nerve transection (CSNT) on post-operation day 7 (POD7). Immunohistochemical, Western blot, and RT-PCR analyses revealed bilaterally increased levels of CXCR4 protein and mRNA in both lumbar and cervical DRG neurons after CSNT. Similarly, CXCL12 protein levels increased, and CXCL12 mRNA was upregulated primarily in lumbar DRGs ipsilateral to the nerve lesion. Intrathecal application of the CXCR4 inhibitor AMD3100 following CSNT reduced CXCL12 and CXCR4 protein levels in cervical DRG neurons, as well as the length of afferent axons regenerated distal to the ulnar nerve crush. Furthermore, treatment with the CXCR4 inhibitor decreased levels of activated Signal Transducer and Activator of Transcription 3 (STAT3), a critical transforming factor in the neuronal regeneration program. Administration of IL-6 increased CXCR4 levels, whereas the JAK2-dependent STAT3 phosphorylation inhibitor (AG490) conversely decreased CXCR4 levels. This indicates a link between the CXCL12/CXCR4 signaling axis and IL-6-induced activation of STAT3 in the sciatic nerve injury-induced pro-regenerative state of cervical DRG neurons. The role of CXCR4 signaling in the axon-promoting state of DRG neurons was confirmed through in vitro cultivation of primary sensory neurons in a medium supplemented with CXCL12, with or without AMD3100. The potential involvement of conditioned cervical DRG neurons in the induction of neuropathic pain is discussed. Full article