Search Results (117)

Brain–computer interface-based (BCI) training induces neural plasticity and promotes motor recovery in stroke patients by pairing movement intentions with congruent electrical stimulation of the affected limb, eliciting somatosensory afferent feedback. However, this training can potentially be refined further to enhance rehabilitation outcomes. It is not known how specific the afferent feedback needs to be with respect to the efferent activity from the brain. This study investigated how corticospinal excitability, a marker of neural plasticity, was modulated by four types of BCI-like interventions that varied in the specificity of afferent feedback relative to the efferent activity. Fifteen able-bodied participants performed four interventions: (1) wrist extensions paired with radial nerve peripheral electrical stimulation (PES) (matching feedback), (2) wrist extensions paired with ulnar nerve PES (non-matching feedback), (3) wrist extensions paired with sham radial nerve PES (no feedback), and (4) palmar grasps paired with radial nerve PES (partially matching feedback). Each intervention consisted of 100 pairings between visually cued movements and PES. The PES was triggered based on the peak of maximal negativity of the movement-related cortical potential associated with the visually cued movement. Before, immediately after, and 30 min after the intervention, transcranial magnetic stimulation-elicited motor-evoked potentials were recorded to assess corticospinal excitability. Only wrist extensions paired with radial nerve PES significantly increased the corticospinal excitability with 57 ± 49% and 65 ± 52% immediately and 30 min after the intervention, respectively, compared to the pre-intervention measurement. In conclusion, maximizing the induction of neural plasticity with an associative BCI requires that the afferent feedback be precisely matched to the efferent brain activity. Full article

Anaesthesia in avian species presents significant challenges due to high peri-anaesthetic mortality rates and marked anatomical variability. Multimodal anaesthetic protocols incorporating locoregional techniques are advocated to improve analgesia and minimise systemic drug requirements. While brachial plexus blocks are described for avian wing surgery, the proximity to major vessels and air sacs increases the risk of complications. This study introduces the “Avian-RUM block,” a novel locoregional technique for the distal wing, adapted from the mammalian RUMM block but modified to reflect avian neuroanatomy, which lacks a distinct musculocutaneous nerve. Twelve rock doves (Columba livia) and twelve hooded crows (Corvus cornix) received transcutaneous injections of a dye solution targeting the radial and median-ulnar nerves at two volumes (0.15 and 0.3 mL/kg). Both species demonstrated high rates of nerve staining and procedural feasibility, with no significant difference in staining length between volumes. An illustrative clinical application of the Avian-RUM block in a domestic goose is also reported to contextualise the cadaveric findings within a multimodal perioperative setting. The results confirm the feasibility of the Avian-RUM block and its potential as a simple, equipment-free technique for regional anaesthesia of the avian wing. These findings provide a foundation for future clinical validation across bird species. Full article

Background and Clinical Significance: Wartenberg’s syndrome (cheiralgia paresthetica) is classically described as a pure sensory neuropathy of the superficial branch of the radial nerve (SBRN). However, in rare circumstances, dynamic mechanical irritation around the radial styloid may produce an atypical clinical phenotype with concurrent motor impairment, broadening the clinical significance of recognizing motion-related compression mechanisms. Case Presentation: A 35-year-old woman presented with persistent dorsoradial wrist pain and numbness, accompanied by progressive weakness of thumb extension, five years after a conservatively treated nondisplaced scaphoid fracture. Neurological examination demonstrated sensory loss in the SBRN distribution and Medical Research Council (MRC) grade 3/5 strength of the extensor pollicis longus (EPL). Nerve conduction studies revealed a markedly prolonged EPL motor latency (4.5 ms; normal ≤ 2.5 ms) with preserved sensory conduction. High-resolution ultrasound showed focal enlargement of the SBRN (cross-sectional area 0.13 cm²) and, critically, dynamic snapping of the nerve over the radial styloid that reproduced the patient’s symptoms. The patient underwent ten weekly sessions of ultrasound-guided hydrodissection with 5% dextrose. After treatment, the pain Visual Analog Scale improved from 8/10 to 0/10 and EPL strength recovered to MRC 5/5. Follow-up nerve conduction studies demonstrated normalization of EPL motor latency (2.1 ms), and repeat ultrasound confirmed resolution of SBRN enlargement and snapping. Conclusions: This case expands the phenotype of Wartenberg’s syndrome to include mixed sensory–motor involvement associated with dynamic SBRN snapping at the radial styloid. Dynamic ultrasound was pivotal for identifying the motion-dependent mechanism, and ultrasound-guided 5% dextrose hydrodissection achieved complete sensory and motor recovery as a minimally invasive and effective treatment option. Full article

Due to the complex anatomical structure of the distal humerus, elbow joint, and the soft tissue mantle (the triceps brachii muscle, large nerves, and vessels), fractures of the distal humerus and humeral condyle are difficult to treat. In most cases, strong instrumentation is needed to stabilize the fractures. To improve exposure of the distal humerus and humeral condyle, we proposed a caudolateral approach that involves elevating the anconeus muscle and splitting the triceps brachii. This study presents the results of using this approach in 16 canine cadavers. After exposing the distal humerus and maximally flexing the elbow joint, photographs were taken of the condyle from the same distance before and after olecranon osteotomy. The visible surface area of the articular cartilage was then calculated in square pixels after calibrating the photographs. It was possible to reach the distal and middle humerus in all cases. The only vital structure that could be easily identified and protected in all cadavers was the radial nerve. The visible area of the articular surface of the humeral condyle increased after olecranon osteotomy. The A₀ (visible area before osteotomy) was significantly smaller than the A₁ (visible area after osteotomy) in all dogs (p < 0.001). The ratio of A₀ to A₁ ranged from 57% to 67% in 15 dogs (median: 64%, interquartile range (IQR): 61–66%), with a very high value of 85% observed in one dog. This experiment used cadavers with intact elbows. This could limit the study’s findings because the effectiveness of the proposed access in reducing T-Y fractures was not assessed. The caudolateral approach is a valuable alternative to other methods for treating T-Y humeral fractures in dogs. Olecranon osteotomy widens access to the condyle. Further studies are needed to evaluate the necessity of olecranon osteotomy in clinical cases. Full article

Background: Peripheral nerve injuries affect a significant proportion of patients with upper extremity trauma, with transections frequently requiring surgical intervention. While direct repair (DR) remains the historical standard, connector-assisted repair (CAR) has been proposed to improve functional outcomes by addressing limitations inherent to DR, such as fascicular misalignment and tension at the repair site. Objectives: The purpose of this systematic review is to evaluate and compare the clinical effectiveness and complication rates of DR versus CAR in upper extremity peripheral nerve injuries. Methods: A systematic search of the PubMed, Scopus, and Ovid MEDLINE databases was conducted for clinical studies published between January 1980 and August 2025 that reported sensory outcomes after DR or CAR for peripheral nerve injuries in the upper limb. Studies were included if sensory outcomes could be categorized using the Medical Research Council Classification (MRCC) scale. The primary outcome was the rate of meaningful sensory recovery (MR), defined as MRCC ≥ S3, with a secondary threshold of MRCC ≥ S3+. Secondary outcomes included postoperative neuroma formation, cold intolerance, pain scores, altered sensation, and revision rate. Statistical analysis was performed using two-sided Fisher exact tests and unpaired t-tests, with p < 0.05 considered significant. Results: A total of 441 patients (DR) and 338 (CAR) were included, with mean ages of 34.2 and 37.3 years and a male predominance (79.7% vs. 73.8%). Overall, 705 nerves in DR and 436 in CAR were treated, mainly digital (86.4% vs. 79.9%), followed by ulnar, median, and radial. Sensory nerves predominated (86.4% vs. 81.6%), with mixed nerves more frequent in CAR (22.5%). Most injuries were Grade I (73% vs. 72.1%), with similar rates of Grades II–III. In the CAR group, the most used conduit was collagen type I (58.3%). Sensory recovery (S3+ and S4) was higher in CAR (69.3%) than DR (50.8%), while DR showed lower two-point discrimination >15 mm. Motor recovery was limited, with better values in DR. DASH scores averaged 13.2 (DR) and 18.2 (CAR), with follow-up of 26 and 23.8 months. Complications were more frequent in DR for cold intolerance, altered sensation, and pain, whereas neuromas, revisions, and fistulas were higher in CAR. Conclusions: Connector-assisted repair demonstrates better sensory recovery and less cold intolerance than DR in small-gap upper-extremity nerve injuries but with higher post-interventional risks and costs. DR remains effective for closely approximated nerves. Randomized trials are warranted, as current evidence is heterogeneous and mostly observational. Full article

Effective metabolic waste clearance and maintaining ionic homeostasis are essential for the health and normal function of the central nervous system (CNS). To understand its mechanism and the role of fluid flow, we develop a multidomain electro-osmotic model of optic-nerve microcirculation (as a part of the CNS) that couples hydrostatic and osmotic fluid transport with electro-diffusive solute movement across axons, glia, the extracellular space (ECS), and arterial/venous/capillary perivascular spaces (PVS). Cerebrospinal fluid enters the optic nerve via the arterial parivascular space (PVS-A) and passes both the glial and ECS before exiting through the venous parivascular space (PVS-V). Exchanges across astrocytic endfeet are essential and they occur in two distinct and coupled paths: through AQP4 on glial membranes and gaps between glial endfeet, thus establishing a mechanistic substrate for two modes of glymphatic transport, at rest and during stimulus-evoked perturbations. Parameter sweeps show that lowering AQP4-mediated fluid permeability or PVS permeability elevates pressure, suppresses radial exchange (due mainly to hydrostatic pressure difference at the lateral surface and the center of the optic nerve), and slows clearance, effects most pronounced for solutes reliant on PVS–V export. The model reproduces baseline and stimulus-evoked flow and demonstrates that PVS-mediated export is the primary clearance route for both small and moderate solutes. Small molecules (e.g., A$\beta$) clear faster because rapid ECS diffusion broadens their distribution and enhances ECS–PVS exchange, whereas moderate species (e.g., tau monomers/oligomers) have low ECS diffusivity, depend on trans-endfoot transfer, and clear more slowly via PVS–V convection. Our framework can also be used to explain the sleep–wake effect mechanistically: enlarging ECS volume (as occurs in sleep) or permeability increases trans-interface flux and accelerates waste removal. Together, these results provide a unified physical picture of glymphatic transport in the optic nerve, yield testable predictions for how AQP4 function, PVS patency, and sleep modulate size-dependent clearance, and offer guidance for targeting impaired waste removal in neurological disease. Full article

Objective: This cross-sectional survey aimed to comprehensively gather data on radial forearm free flap (RFFF) utilization and practices in head and neck reconstructive surgery. Methods: An online questionnaire was organized into seven sections: demographics, surgeon experience, harvesting techniques, microsurgical considerations, postoperative care, flap monitoring, and outcomes. It was distributed by email to 216 head and neck reconstructive surgeons who attended the International Federation of Head and Neck Oncologic Societies (IFHNOS) congress in Rome (21–25 June 2023) using the congress mailing list. Responses were collected from 54 surgeons (25% response rate), representing 15 countries across Europe, Asia, the Americas, and Oceania, underscoring the international scope of the survey between 5 February and 25 March 2024. The questionnaire was not formally piloted or validated. Missing data were managed on a per-question basis. Descriptive statistics were used, and 95% confidence intervals (CIs) were calculated for key surgical outcomes to indicate estimate precision. Associations between categorical variables were analyzed using Pearson’s χ² test with Cramér’s V as an effect size, and relationships between continuous variables were examined using Spearman’s rank correlation (ρ) with 95% confidence intervals (CIs). Given the exploratory design and limited sample size, no correction for multiple comparisons was applied, and the risk of both Type I and Type II errors was acknowledged. Results: Variations were observed in harvesting techniques, microsurgical preferences, and postoperative care protocols. Most surgeons initiated flap harvesting concurrently with tumor resection, primarily preserving superficial sensory nerves. Regarding venous outflow, 50% of respondents preferred the cephalic vein, 19% used comitant veins, and 29% utilized both systems when possible. Perioperative antibiotic use was standard practice, though anticoagulant preferences and flap monitoring methods varied. The study achieved a high success rate for RFFF procedures, exceeding 95%, with venous thrombosis identified as the main cause of flap failure. No significant correlations were found between flap failure rate and training method (p = 0.21), specialty (p = 0.37), annual number of RFFF procedures (p = 0.89), surgeon age (p = 0.42), or hospital type (p = 0.48). Effect sizes were small to moderate, indicating weak or negligible associations. Similarly, perioperative factors such as anticoagulant use (p = 0.84), preoperative antibiotics (p = 0.42), surgical instruments (p = 0.61), suture techniques (p = 0.51), and donor vein selection (p = 0.20) showed no statistically significant associations with flap loss. Patient satisfaction assessments were inconsistent, with only 39% of surgeons routinely performing them. Conclusions: The study provides valuable insights into current RFFF practices and outcomes across an international cohort of head and neck surgeons, highlighting patterns and variability in techniques, perioperative care, and monitoring strategies. Full article

Background: Non-transected and partially transected peripheral nerve injuries (neuromas-in-continuity) are relatively common but understudied. Their optimal surgical management and expected outcomes remain unclear. We conducted a literature review of surgical repairs in such lesions and illustrate a case to guide decision-making. Systematic searches of PubMed and Google Scholar identified 70 eligible reports (Level I = 2, Level II = 5, Level III = 37, Level IV = 20, Level V = 4). Across studies, neurolysis of NAP-positive lesions often restored antigravity strength, while direct repair or grafting of nonconductive segments yielded meaningful recovery in ~75%. After neurolysis or reconstruction, ~77–92% of brachial plexus/axillary neuromas-in-continuity reached LSUHSC Grade ≥3. Median/ulnar lesions treated with neurolysis, biologic/vascularized coverage, or reconstruction showed reliable pain relief but variable sensory/motor recovery. Radial/PIN lesions improved in some series irrespective of NAPs. Earlier intervention, shorter gaps, distal sites, and younger age correlated with superior outcomes. Meanwhile, prolonged observation risking end-organ atrophy degraded results. Adjuncts such as electrical stimulation and wraps may aid reinnervation or reduce scarring, though high-quality evidence is limited. Conclusions: For non-transected and partially transected PNIs, a pragmatic approach emerges: Observe low-grade injuries with serial examinations. Explore early if recovery stalls (≈3–6 months). Use NAP-guided neurolysis for conductive lesions. Perform tension-free repair or grafting for nonconductive segments, adding anti-adhesive coverage when appropriate. Standardized reporting and prospective trials are needed to refine timing, technique selection, and patient-reported outcomes. Full article

Background: Humeral shaft fractures (HSFs) represent 13–25% of humeral fractures and are frequently complicated by radial nerve palsy and nonunion. While conservative management was historically preferred, surgical fixation with intramedullary nailing (IMN) has gained increasing popularity. The aim of this study was to evaluate the effectiveness of IMN in the treatment of HSFs, focusing on postoperative complications and functional outcomes. Methods: A bicenter retrospective analysis was conducted on 202 patients who underwent antegrade IMN fixation for HSF between 2014 and 2019, with a minimum follow-up of four years. Demographic data, trauma characteristics, surgical details, and postoperative complications were recorded. Functional outcomes were assessed at one year using the Disabilities of the Arm, Shoulder and Hand (DASH), Oxford Shoulder Score (OSS), Constant Shoulder Score (CSS), and Visual Analogue Scale (VAS). Statistical analysis included ANOVA, Student’s t-test, Spearman’s correlation, and multivariate regression. Results: The mean follow-up was 57.7 ± 19.6 months. At one year, mean OSS, DASH, CSS, and VAS scores were 39.0, 16.6, 73.5, and 0.9, respectively. Excellent or good Constant outcomes were recorded in 89.6% of patients. Sixteen complications (7.9%) occurred, including nerve injuries (4.0%) and pseudoarthrosis (1.5%). Patients operated within 48 h had significantly better functional scores compared to those treated later (p < 0.01). No differences were found according to fracture pattern, sex, diabetes, or osteoporosis. Age showed a weak correlation with functional outcomes. Conclusions: IMN is a safe and effective option for the treatment of HSFs, with high rates of functional recovery and a low incidence of complications. Early surgical intervention appears to improve outcomes, supporting its role as a valuable strategy in HSF management. Full article

Background: Hypothyroidism has been implicated as a risk factor for carpal tunnel syndrome (CTS). However, the effect of hypothyroidism on the risk of CTS has not been studied in large, non-selective clinic populations, and the impact of hypothyroidism on electrodiagnostic parameters remains inadequately understood. Methods: In this retrospective study, we examined 480 patients referred for upper limb electrodiagnostic evaluation. We compared the prevalence of CTS among patients with and without hypothyroidism, adjusting for age and gender. Additionally, we compared the median nerve sensory and motor latencies and comparative latency studies (COLS) [median-to-ulnar comparison through palmar difference (Palmdiff) and ring difference studies (Ringdiff); and median-to-radial comparison through a thumb difference study (Thumbdiff)] among patients with and without hypothyroidism disease, stratified by CTS status and age groups. Results: The crude prevalence of CTS was higher among patients with hypothyroidism (79.7%) compared to those without (61.8%) (p = 0.005). However, after adjusting for age and gender, logistic regression analysis revealed a non-significant association between hypothyroidism and CTS (adjusted odds ratio (OR): 1.71; 95% CI: 0.89–3.28, p = 0.106). CTS was more prevalent among patients with hypothyroidism under 50 years of age (OR: 2.59; 95% CI: 1.17–5.73, p = 0.018). There were no significant differences in any electrodiagnostic parameters between patients with and without hypothyroidism among CTS and non-CTS groups. Conclusions: Hypothyroidism increased the risk of CTS among patients under 50 years of age. The electrodiagnostic parameters used for CTS diagnosis were not influenced by the presence of hypothyroidism. Full article

Background/Objectives: Radial head arthroplasty (RHA) and open reduction and internal fixation (ORIF) have emerged as predominant methods of surgical management for radial head fractures. The objective of this study was to evaluate national trends in management of radial head fractures among ABOS oral examination candidates and to compare complication rates between RHA and ORIF. Methods: A search of the American Board of Orthopaedic Surgery (ABOS) oral examination database identified radial head fractures treated with RHA or ORIF between 2003 and 2021 in patients 18 years or older. Results: RHA cases increased significantly from 2003–2021 (p < 0.001). Patients undergoing RHA were older (52.4 years vs. 42.9 years, p < 0.001) and predominantly female (60.8% vs. 45.7%, p < 0.001). Medical and surgical complications within 60 days were higher after RHA (2.9% vs. 1.6%, p = 0.012; 24.9% vs. 20.4%, p = 0.001), most commonly stiffness (10.8% vs. 7.1%, p < 0.001), nerve injury (3.3% vs. 2.7%, p = 0.26), and implant failure (3.4% vs. 2.4%, p = 0.064). Non-union or delayed union (0.5% vs. 2.5%, p < 0.001) was significantly higher after ORIF, and fracture (1.1% vs. 0.3%, p = 0.008) was significantly higher after RHA. The highest proportion of RHA to ORIF was performed by surgeons with shoulder and elbow fellowship training (p < 0.001). Conclusions: Among ABOS Candidates, RHA volume surpassed ORIF for radial head fractures in 2010. Surgical complication rates for radial head fractures are high at 60 days follow-up for both procedures. RHA is associated with higher complication rates, especially stiffness; however, similar reoperation and readmission rates suggest that RHA may have been selected for more complex injuries. Full article

Background: Primary lymphoma of peripheral nerves (PLPN) is a rare extranodal non-Hodgkin lymphoma that mimics benign nerve conditions, leading to diagnostic delays. This systematic review evaluates the clinical, radiological, and pathological features of PLPN, alongside diagnostic and therapeutic strategies. Materials and Methods: A systematic search was conducted across PubMed, Scopus, and Web of Science, and identified 23 studies reporting 27 cases of PLPN. Data on demographics, clinical presentation, diagnostics, treatment, and outcomes were extracted and synthesized qualitatively due to study heterogeneity. Results: The sciatic nerve was most involved (48.15%), followed by the ulnar (18.5%) and radial nerves (18.5%). The median age at diagnosis was 58 years, with symptoms including motor deficits (88.9%), sensory disturbances (74.1%), and pain (70.4%). B-cell lymphomas accounted for 81.5% of cases, predominantly diffuse large B-cell lymphoma. MRI findings were non-specific; however, diffusion-weighted imaging (DWI) showed diagnostic potential. Treatments included combination therapies (51.9%), chemotherapy (25.9%), and surgery. Complete remission was achieved in 70.8%, with a 2-year survival rate of 83.3%. Conclusions: PLPN is rare but likely underdiagnosed. Early recognition requires multidisciplinary collaboration, advanced imaging, and standardized protocols. Future research should focus on molecular characterization, diagnostic criteria, and treatment optimization to improve outcomes for this challenging condition. Full article

Background/Objectives: Radial artery access (RAA) is widely used for catheter-based procedures due to its safety and convenience, but complex regional pain syndrome (CRPS) remains a rare, underrecognized complication—particularly in women. CRPS manifests as prolonged, severe pain and autonomic symptoms, often associated with nerve irritation near the carpal tunnel. This study aimed to evaluate whether modifying the puncture site to a high radial artery puncture (HRAP) reduces the risk of CRPS in patients undergoing transarterial micro-embolization (TAME) for frozen shoulder. Methods: We retrospectively reviewed 97 patients (47 women and 50 men) who underwent transarterial micro-embolization (TAME) via conventional RAA for frozen shoulder between February and June 2019. The occurrence of CRPS and vascular complications was recorded. All punctures were ultrasound-guided. Results: Among women treated via conventional RAA, five developed CRPS and one had radial artery occlusion. CRPS symptoms included intense puncture site pain (mean duration was 47 days), which severely impaired daily function. No complications occurred in men. Following the adoption of HRAP, no cases of CRPS, prolonged pain, or vascular complications were observed in the consecutive 101 women treated. Conclusions: Our findings suggest HRAP reduces CRPS risk by avoiding superficial nerve branches and targeting deeper arterial segments with fewer sensory structures. This ultrasound-guided modification is simple, does not require additional training, and may be widely applicable in both musculoskeletal and cardiovascular interventions. HRAP may help minimize neuropathic complications in broader patient populations. Full article

Background and Clinical Significance: Radial nerve palsy typically presents as wrist drop due to nerve compression, with conventional management often yielding prolonged recovery. We report a case where ultrasound-guided hydrodissection (HD) with 5% dextrose in water (D5W) achieved immediate functional restoration, suggesting neurapraxia as the underlying pathology. Case Presentation: A 54-year-old diabetic female presented with acute left wrist drop without trauma. Examination confirmed radial nerve palsy (MRC grade 0 wrist extension), while radiographs ruled out structural causes. Ultrasound revealed fascicular swelling at the spiral groove. Under real-time guidance, 50 mL D5W (no local anesthetic) was injected to hydrodissect the radial nerve. Immediate post-procedure assessment showed restored wrist extension (medical research council (MRC) grade 4+). At one- and three-month follow-ups, the patient maintained complete resolution of symptoms and normal function. Conclusions: This case highlights two key findings: (1) HD with D5W can serve as both a diagnostic tool (confirming reversible neurapraxia through immediate response) and therapeutic intervention, and (2) early HD may circumvent prolonged disability associated with conservative management. The absence of electrodiagnostic studies limits objective severity assessment, though ultrasound localized the lesion. While promising, these observations require validation through controlled trials comparing HD to standard care, particularly in diabetic patients with heightened compression susceptibility. Technical considerations—including optimal injectate volume and the role of adjuvant therapies—warrant further investigation. US-guided HD with D5W emerges as a minimally invasive, surgery-sparing option for acute compressive radial neuropathies, with potential to redefine treatment paradigms when applied at symptom onset. Full article