The Effect of Electrical Stimulation on Median Nerve Recovery After Repair in Rats

This study aimed to summarize evidence on peripheral nerve enlargement in patients with diabetes, with and without diabetic sensorimotor polyneuropathy (DSP), compared with healthy controls. PubMed and Embase were systematically searched for ultrasound studies measuring the cross-sectional area (CSA) of peripheral nerves in patients with diabetes with and without DSP. The primary outcome was the weighted inter-group mean difference in CSA at all reported upper- and lower extremity sites. Forty-seven studies were identified, of which 41 were included in the meta-analyses. Patients with diabetes without DSP showed significantly larger CSA values than healthy controls at 3 of 11 anatomical locations, all located in the lower extremity. Patients with diabetes and DSP demonstrated increased CSA compared with controls at 9 of 14 sites, particularly at distal compression sites of the median and tibial nerves. Compared with patients with diabetes without DSP, those with DSP had significantly larger CSA values at 14 of 21 sites, with the greatest difference observed 4-5cm proximal to the medial malleolus (pooled mean difference+5.26mm2, 95% CI 0.94-9.57). In conclusion, peripheral nerve CSA is increased in diabetes and further enlarged in the presence of DSP, with the largest effects at distal compression sites.

Carpal tunnel syndrome (CTS) and cubital syndrome (CuTS) are common neuropathies typically associated with upper-extremity surgeries or systemic risk factors. This study investigates the incidence of CTS and CuTS following anterior cervical discectomy and fusion (ACDF), total hip arthroplasty (THA), and total knee arthroplasty (TKA) to evaluate whether postoperative upper-extremity neuropathy is linked to perioperative systemic responses, patient-specific risk factors, or a combination of the above. Patients who underwent ACDF, primary THA, or primary TKA at a single institution between 2015 and 2025 were retrospectively reviewed. Cases of postoperative CTS or CuTS were identified based on clinical presentation and electrodiagnostic testing when available. Each chart was reviewed to confirm the diagnosis, timing, and extract clinical details. Demographic, diagnostic, surgical, and clinical outcomes were compared between cohorts. Among 49,752 patients, 463 (0.93%) developed postoperative CTS and/or CuTS. The observed incidence was highest in the ACDF cohort (3.05%) compared to TKA (0.88%) and THA (0.82%). CTS accounted for 78% of cases, CuTS for 11%, and combined CTS/CuTS for 11%. Neuropathy distribution varied considerably by surgical group, with ACDF patients having higher rates of CuTS and combined CTS/CuTS diagnoses. Time to diagnosis was shorter in the ACDF group compared to other groups. Surgical decompression was performed in 69.5% of cases, with symptom resolution in 90.4%. Of the 30.5% managed conservatively, 34.8% reported persistent symptoms. Upper-extremity neuropathy can develop following nonupper extremity surgeries, particularly ACDF. The timing and pattern suggest that perioperative systemic and patient-level factors may contribute more substantially toward neuropathy development than local surgical effects. Prognostic III.

Associations Between Preoperative Diagnostic Tests and Surgical Recommendation for Carpal Tunnel Syndrome.

Incidence of Carpal Tunnel Syndrome After the Diagnosis of Ulnar Neuropathy.

AB-530. First experience with novel digital signal-to-noise management of median nerve somatosensory evoked potentials

Background: 3,4-methylenedioxymethamphetamine (MDMA), or "Ecstasy," is a semi-synthetic stimulant and hallucinogen widely used recreationally. While known for producing euphoria, it is associated with severe medical complications including serotonin syndrome, rhabdomyolysis, and multi-organ failure. Although MDMA is known to cause various vascular and muscular lesions, deep venous thrombosis (DVT) in the upper limbs remains a rare but serious consequence. Case Presentation: A 20-year-old male was admitted to the emergency department after consuming ecstasy, Zepam, and alcohol. He presented with classic signs of serotonin syndrome (disturbed consciousness, hyperhidrosis, tremors, and fever) alongside intense pain and significant edema in the left upper limb. Diagnostics: Venous echodoppler confirmed thrombosis of the left humeral and axillary veins. Laboratory tests revealed severe rhabdomyolysis (CPK: 23,304) and hepatic cytolysis. Management: Treatment included anticoagulant therapy (low-molecular-weight heparin transitioned to Rivaroxaban), hydration, and analgesics. Complications: On day 7, the patient developed compartment syndrome due to worsening edema. While the edema eventually regressed by day 9, the patient suffered persistent sensitivomotor deficits across the median, ulnar, radial, and musculocutaneous nerves. Discussion: The relationship between MDMA use and thrombosis may be linked to the inflammatory response and extensive muscle damage seen in rhabdomyolysis, similar to the mechanisms observed in inflammatory myopathies. While other sites of MDMA-induced thrombosis (renal and aortic) have been documented, upper limb DVT is less common. Conclusion: MDMA use can lead to life-altering, multi-visceral damage. Despite multidisciplinary management, the prognosis for such cases can be poor due to lasting nerve damage and muscle atrophy resulting from vascular and compartment complications.

Skeletal muscle undergoes progressive denervation-induced muscle atrophy (DIMA) after peripheral nerve injury that severely impairs the potential for motor functional recovery with reinnervation. There are currently no therapeutic strategies to reverse the deleterious effects of chronic DIMA, leaving affected patients with lifelong disability. Herein, we used a translational rodent forelimb nerve injury model to investigate whether targeted injection of syngeneic myoblasts to chronically atrophic muscle can reverse the histologic and functional consequences of DIMA. Male Lewis rats underwent median nerve transection followed by immediate (positive control) or delayed repair. Following a plateau of motor function, myoblasts were injected into the digital flexor muscles (n = 5-6 per group), delivered in either saline or a nanofiber hydrogel composite (NHC) loaded with agrin- and insulin-like growth factor 1 (IGF-1)-releasing nanoparticles (npNHC). Serial functional assessments of stimulated grip strength and terminal histological evaluation were used to measure recovery. Satellite cell-rich (Pax7Hi) myoblast therapy caused sustained improvement in stimulated grip strength from pretreatment baseline (p < 0.05). Histological evaluation demonstrated that myoblast therapy, when delivered in npNHC, reversed whole muscle atrophy compared to positive controls [p = 0.997 and 0.996] and restored mean myofiber cross-sectional area [p = 0.244]. Correlation analysis demonstrated functional improvements were associated with increased myofiber cross-sectional area [r = 0.900, p = 3.01E-09]. This data indicates that targeted injection of syngeneic myoblasts can reverse the functional and histologic effects of DIMA in skeletal muscles and is a promising strategy for improving recovery after peripheral nerve injuries.

Background: In the modern era new technology has overflowed in each and every field. Many things are getting mechanized overnight. Manual labour is getting reduced or replaced by newly developed instruments and robotic machines. Even then many machines are operated by human beings only. Electricians use hand held drilling machines routinely and because of that are exposed to hand vibration. So they are at high risk of developing either HAVS, carpel tunnel syndrome (CTS) or both. Material &amp; methods: In the present study 40 electricians using drill machines &amp; 40 Controls (not exposed to hand vibration) were selected and Nerve conduction study (NCS) of both upper limbs was carried out. Motor &amp; sensory nerve conduction of Ulnar, Median &amp; Radial nerves was studied. Results of both the groups were compared. Results:The Distal Motor &amp; sensory Latency (Min.) of both Median, both Radial &amp; both Ulnar was significantly prolonged in study group compared to control Group (p &lt; 0.05).The amplitude of CMAP of both Median, both Ulnar &amp; Left Radial was significantly reduced in study group compared to control Group (p &lt; 0.05). The amplitudes of SNAPs &amp; sensory conduction velocities were significantly reduced in study group compared to control group. Motor conduction velocities of Ulnar, Median &amp; Radial on both sides were significantly reduced in subjects compared to control Group (p &lt; 0.05). Conclusion:From our study we conclude that the long term repetitive exposure to hand vibration is associated with distal neuropathy more of sensory than motor. The median nerve is mostly affected but in few cases there is also involvement of ulnar &amp; radial nerve. Dominant hand is affected most of the time. However in few cases there is bilateral involvement.

Rheumatoid arthritis (RA) patients are prone to carpal tunnel syndrome (CTS). MRI can accurately detect median nerve swelling associated with CTS as well as evaluate synovial inflammation and structural damage. A median nerve cross-sectional area (CSA) of > 15 mm2 is the best MRI diagnostic criterion of CTS. This study investigates the prevalence of median nerve swelling in early RA patients, its relationship to inflammation and structural damage, and long-term outcome following treatment. Retrospective study of early RA patients who underwent clinical, serology, radiography, and dynamic contrast-enhanced MRI of the wrist at baseline, year 1, and year 8. Median nerve cross-sectional area (CSA), median nerve enhancement and perfusion, retinacular bowing, synovial inflammation, structural damage and functional impairment were assessed. 81 early RA patients (age: 54 ± 13 years, F/M: 64/17) were studied. Undue median nerve swelling was present in 25 (31%) at baseline and 37 (46%) of 81 ERA patients at year 8. Undue median nerve swelling was moderately (r = 0.634) related to tenosynovitis volume at baseline but was otherwise not related to synovitis and structural damage at either baseline, year 1, or year 8. Median nerve swelling did not regress long-term. At year 8, CTS symptoms were present in about half of RA patients and were not related to median nerve swelling. Functional impairment at year 8 was more frequent in patients with median nerve swelling. Undue median nerve swelling is common in RA patients, is not related to synovitis or structural damage, does not regress with treatment, and is linked to long-term functional impairment. Median nerve swelling, indicative of carpal tunnel syndrome, is common in RA patients, does not regress with reduction in synovitis or tenosynovitis after treatment and is associated with more severe and more frequent systemic functional impairment. Almost one-third of RA patients fulfilled MRI criteria for carpal tunnel syndrome (CTS) diagnosis at baseline, increasing to almost one-half of patients at year 8. Long-term median nerve swelling is not related to tenosynovitis, synovitis or structural damage. Functional impairment was over twice as common in patients with undue median nerve swelling than those without undue median nerve swelling.

Osteopathic manipulative treatment (OMT) has been recognized as a conservative management option for patients with carpal tunnel syndrome (CTS), although limited research exists to validate its ability to effect posttreatment changes in the median nerve or the surrounding soft tissues. The objectives of this study are to evaluate and quantify changes in the elasticity of the median nerve, transverse carpal ligament (TCL), and intracarpal tunnel soft tissues in patients treated for CTS with traditional conservative therapy (e.g., steroid injection and splinting), OMT, or OMT plus conservative therapy. This single-blinded, randomized controlled pilot study included patients with a definitive diagnosis of mild to moderate-severe CTS. Participants were assigned to one of the three treatment groups utilizing a random number generator. Analysis of variance (ANOVA) was conducted to compare the following outcome measures from baseline through 6weeks of treatment across the three groups of interest: the CTS-6 assessment tool and the shortened version of the Disabilities of the Arm, Shoulder, and Hand (Quick-DASH) questionnaire, electromyography (EMG) of the median nerve, grayscale ultrasound evaluation of the cross-sectional area (CSA) of the median nerve, and shear wave elastography (SWE) of the median nerve, TCL, and the intracarpal tunnel contents (ICTC). Associations between EMG severity scores, CTS-6 assessments, and Quick-DASH scores were also explored through correlation analyses. Among the 15 wrists randomized to the study, 5 withdrew, primarily due to the inability to complete all follow-up visits. 10 wrists completed the study: 3 in the conservative group, 4 in the OMT group, and 3 in the OMT plus conservative group. Ultrasound and SWE were effective in measuring median-nerve CSA and stiffness, although changes through 6weeks were generally limited. There was no significant difference in the CSA measurements of the median nerve throughout the study (p=0.22, 0.11, 0.18, and 0.71 at weekly visits 1, 3, 5, and 7, respectively). Only the conservative therapy group showed notable reductions in CSA and stiffness over time, which corresponded to statistically nonsignificant reductions in CTS-6 survey scores (ANOVA analysis at visit 6 producing p=0.35) and Quick-DASH scores (p=0.12). One ANOVA analysis of the TCL average shear velocity did produce significant results at visit 7 (OMT mean=4.1, combination mean=3.5, conservative mean=3.7, p=0.01). Changes in EMG parameters (amplitude, latency, and conduction velocity of the median nerve) from baseline through 6weeks were variable, with no clear pattern of change in any group. Similarly, there was weak association between EMG severity scores and CTS-6 (R2=0.1463) and Quick-DASH scores (R2=0.4676). History and clinical examination are the primary means of establishing the diagnosis of CTS, with EMG and imaging playing supportive roles. The use of grayscale ultrasound and SWE as alternative, noninvasive diagnostic means in establishing a diagnosis of CTS continues to be explored. Given that SWE can serve as a reproducible, noninvasive, and objective means of evaluating the stiffness of soft tissues prior to and following various forms of treatment, further studies should be undertaken to investigate its utility and value in providing objective evidence of the efficacy ofOMT.

Carpal Tunnel Release Surgical Techniques.

Following C5 and C6 brachial plexus injury there is loss of active elbow flexion. Nerve transfers from ulnar and median nerves have been reported for restoration of innervation to biceps and brachialis. However, fatigue of reinnervated elbow flexors remains a challenge. Double versus single fascicle transfer results are superior (MRC Grade 4 score 83% vs. 63.3%; p = 0.013), considering this we evaluate the feasibility of reinnervating a third muscle to support elbow flexion in terms of minimum reinnervation distance and surgical technique. This study explores the feasibility of nerve transfer to biceps, brachialis, as well as brachioradialis (BR) via a lateral cutaneous nerve of forearm (LCNF) in-situ interposition graft. Eight fresh frozen body donors, of mixed age range and gender, were dissected to measure baseline limb lengths, irrespective of bone circumference to determine: branching motor points for key muscles (biceps, brachialis, and BR) and measure donor nerve fascicle dissection lengths and calculate theoretical reinnervation distances from median nerve to biceps, ulnar nerve to brachialis via MSCN and to BR via the LCNF. The novel transfer from the ulnar nerve to BR using LCNF interposition graft was feasible in all eight limbs. The average fascicle dissection length of the median nerve was 14.63 mm (95% CI: 12.4-16.9) and for the ulnar nerve was 17.5 mm (95% CI: 13.9-21.0). Average theoretical reinnervation distance for BR was 94.13 mm (±23.21, R: 70-145, 95% CI: 77.35-110.90) equivalent to 3 months for reinnervation. With the biceps, reinnervation was 23.0 mm (±3.46, R: 15-35, 95% CI: 17.38-26.82) approximately 4 weeks and was 35.0 mm (±16.23, R: 9-55, 95% CI: 25.5-47.39) or approximately 5 weeks for brachialis, not accounting for latency or intramuscular axon regeneration distances from the motor point. Nerve transfer reinnervation of the BR through a LCNF in-situ graft is feasible with acceptable reinnervation distances. Clinical adoption of this modification to the traditional Oberlin nerve transfer could provide a way of improving elbow flexion strength and endurance through providing more reinnervated muscle mass, with the inclusion of BR.

Peripheral nerve injury is a significant clinical challenge due to its limited regenerative capacity. While immediate repair is generally preferred, delayed repair is often necessary in clinical scenarios where primary intervention is not feasible. Understanding the molecular and genetic mechanisms underlying both conditions is essential for optimizing functional recovery. Thus, this study aimed to investigate key pathways involved in nerve regeneration by conducting the first transcriptomic analysis of a regenerating nerve within a conduit, while also comparing immediate and delayed nerve repair over time in a rat model. Immediately after injury or following a delay of 3 months, microsurgical intervention with a chitosan tube was performed to repair an 8-mm median nerve gap, and regenerated nerves inside the conduit were collected at 14 and 21 days for morphometric analysis and at 7, 14, and 21 days post-repair for RNA sequencing. Morphometric analysis based on absolute values showed a significant reduction in Schwann cell and axonal areas at 14 days, along with a decreased number of blood vessels and an overall smaller section area at 21 days in the delayed repair group. However, when normalized to the total section area to assess the relative proportions occupied by Schwann cells, axons, and vessels, no significant differences were observed between the immediate repair and delayed repair groups at 21 days. To correlate morphometric data with transcriptomic profiles, RNA sequencing was conducted. When comparing regenerating nerves at different time points with a healthy nerve, 25,596 genes were differentially expressed in the immediate group and 25,868 genes in the delayed repair group. These genes were mainly involved in pathways related to inflammatory response, phagocytosis, cell signaling, and response to lipoprotein particles. However, only 137 genes were differentially expressed when comparing the delayed repair group versus immediate repair groups. Gene ontology analysis revealed that the most enriched pathways were related to angiogenesis, particularly at 7 days, which aligned with the higher vessel density observed at 14 days in the delayed group. Overall, the comparison between the experimental groups indicated that immediate repair initiated a more rapid regenerative response, while delayed repair followed a slower, yet ultimately convergent trajectory, highlighting that regeneration is postponed and partially impaired. Notably, the nerve caliber was reduced in the delayed repair group compared to the immediate repair group. These findings emphasize the importance of early intervention and address a critical gap in the field by providing the first transcriptomic comparison of delayed versus immediate repair within conduits, thereby contributing to the development of novel molecular therapies to enhance recovery.

Abstract Background Plantar fasciitis (PF) is a degenerative condition characterized by repetitive microtrauma at the attachment site of the plantar fascia to the calcaneus leading to heel pain and functional impairment. It has many causes like obesity, flat foot and tight shoes. Recent research has suggested that it may also be associated with neuropathy of the medial calcaneal nerve (MCN), which can cause pain and discomfort in the heel and surrounding areas. The current study aimed to investigate the association between medial calcaneal nerve neuropathy and plantar fasciitis through comparative analysis of nerve conduction study parameters and ultrasonographic measurement of plantar fascia thickness in affected patients and healthy controls. Methodology Thirty patients with clinical and ultrasonographic PF were included as patient group in addition to 30 age and sex-matched healthy individuals as control group. They were subjected to detailed history, thorough clinical examination, ultrasound (US) examination of the foot and nerve conduction studies of MCN in addition to routine posterior tibial motor, sural, medial and lateral plantar sensory conduction studies. Results A highly statistically significant increase in the peak sensory latency (PSL) and highly statistically significant reduced amplitude and decreased conduction velocity (CV) of the sensory response of MCN was found in patients group compared to controls ( P &lt; 0.001). A strong correlation was found between parameters of MCN conduction study parameters and clinical/ultrasonographic features. Conclusion The present study demonstrated a significant relationship between ultrasonographic plantar fascia parameters and MCN conduction findings, supporting a neuro–structural interplay in PF. Specifically, plantar fascia thickness showed a strong positive correlation with MCN peak sensory latency and significant negative correlations with both amplitude and conduction velocity, indicating that increasing fascial thickness is associated with worsening nerve conduction. Similarly, pain severity (VAS score) and duration of heel pain exhibited highly significant correlations with all MCN parameters, reinforcing the link between neuropathic dysfunction and clinical burden. The results suggest that plantar fasciitis extends beyond a purely degenerative fascial disorder, encompassing a neuropathic component reflected by measurable changes in nerve conduction. This underscores the value of integrating both ultrasound and neurophysiological assessments to achieve a more comprehensive evaluation and guide targeted management strategies.

Anatomical variations within the carhpal tunnel can contribute to compression of the median nerve. This can include abnormal flexor digitorum superficialis or palmaris profundus muscle bellies underneath the transverse carpal ligament. We report a rare case of an accessory lumbrical muscle found within the carpal tunnel in a patient with clinical carpal tunnel syndrome (CTS). This was found to be a functional lumbrical muscle to the middle finger. On division of the transverse carpal ligament without resection of this muscle, the patient had clinical resolution of their symptoms. This case is the first to show high-quality images of these lumbrical muscles actively functioning in a patient with carpal tunnel syndrome. This highlights the importance of considering anatomical variations in patients with CTS. Careful intraoperative inspection is essential to identify and address these anomalies, ensuring resolution of symptoms, without impairing function.

The median nerve (MN) is a main peripheral nerve that includes superficial motor and sensory fibers in the distal forearm. The proximity of the MN to the forearm muscle tendons and neurovascular structures enhances its clinical significance. The safety of invasive procedures in this area relies on a thorough understanding of the nerve morphometric characteristics. However, commonly used superficial anatomical landmarks may not provide the same reliability for every individual. This study aimed to precisely identify the morphometric features of the MN in the distal forearm by using fixed bony landmarks and to evaluate its positional relationships with nearby anatomical structures. Measurements of the length, width, surface area, and distances from the MN to the ulnar styloid process, radial styloid process, flexor carpi radialis tendon, and ulnar nerve were measured by dissecting the forearms of 31 formalin-fixed cadavers. Differences in gender and side were evaluated, along with the connections between wrist width and various morphometric parameters. There was no statistically significant difference between genders or sides. Without regard to sex or side, the mean distance from the MN to the radial styloid process was 20.97 ± 3.02 mm, to the ulnar styloid process was 19.44 ± 4.83 mm, and to the flexor carpi radialis tendon was 3.83 ± 0.96 mm. The mean surface area of the nerve was 1.49 ± 0.63 cm2. Median nerve-ulnar nerve distance was 12.09 ± 3.77 mm, and it remained within a narrow range. Furthermore, a positive correlation was observed between wrist width and both nerve length and surface area. The morphometric features of the MN in the distal forearm consistently align with bone landmarks, making these structures a more reliable guide than variable superficial tendon references. These data will contribute scientific knowledge to improve the safety of interventional methods, particularly in distal forearm and hand surgery. However, as these findings are based on cadaveric specimens, their direct clinical applicability should be interpreted with caution and warrants further validation in living subjects.

Carpal tunnel syndrome (CTS) is a common neuropathy disease as a result of constriction of the median nerve, leading to pain, numbness, and functional limitation. Although the prevalence of clinically diagnosed CTS is predicted at 3.8% in the general population, certain occupational groups, such as schoolteachers may be at elevated risk. To assess the prevalence and risk factors of CTS between schoolteachers in Al-Madinah Al-Munawwarah city, Saudi Arabia. An online cross-sectional survey was administered among schoolteachers in Al-Madinah Al-Munawwarah using a validated Arabic version of the Boston carpal tunnel questionnaire-A. A total of 268 participants provided sociodemographic and clinical data, including symptom severity scale (SSS) and functional status scale (FSS) scores. Descriptive statistics summarized sociodemographic and clinical data. Continuous variables were expressed as means, medians, and standard deviations. The Mann-Whitney and Kruskal-Wallis tests compared SSS and FSS scores, whereas Chi-square and Fisher's exact tests assessed categorical associations. Clinically diagnosed CTS was reported by 5.2% of participants, whereas 47.3% reported CTS-related symptoms, and 32.1% experienced functional difficulties. Mild symptoms were most common (31.7%). Pregnancy and the presence of multiple comorbidities were significantly associated with higher SSS and FSS scores (P < 0.001). CTS-related symptoms and functional limitations are common among schoolteachers in Al-Madinah Al-Munawwarah, particularly in pregnant teachers or those with multiple comorbidities. These findings highlight the need for preventive strategies and awareness programs in educational settings.

Background/Objectives: The paretic wrist after stroke may exhibit median nerve conduction abnormalities, but factors underlying hemiplegic-contralateral asymmetry remain uncertain. We compared electrodiagnostic and ultrasonographic wrist measures between sides and assessed predictors of side-to-side differences in distal motor latency (ΔDML) and distal sensory latency (ΔDSL). Methods: We retrospectively analyzed 85 patients with stroke. Distal motor latency (DML), distal sensory latency (DSL), wrist-to-forearm ratio (WFR), and median nerve inlet cross-sectional area (CSA) were measured bilaterally. Paired t-tests evaluated hemiplegic-contralateral differences, and Wilcoxon signed-rank tests were performed as sensitivity analyses. Multivariable linear regression with robust (HC3) standard errors modeled ΔDML as the primary outcome and ΔDSL as the secondary outcome, with wrist flexor spasticity (Modified Ashworth Scale, MAS) specified a priori as the primary explanatory variable; extended models additionally included ΔWFR. Sensitivity analyses re-specified MAS as an ordered category, and complementary linear mixed-effects models using raw bilateral latency values were fitted to assess the robustness of Δ-based modeling. Results: The hemiplegic side showed higher DML (5.51 ± 0.79 vs. 4.81 ± 0.42 ms; mean difference 0.694; p < 0.001), DSL (4.51 ± 0.88 vs. 3.66 ± 0.45 ms; mean difference 0.852; p < 0.001), WFR (1.21 ± 0.30 vs. 1.07 ± 0.16; p = 0.008), and CSA (11.16 ± 3.67 vs. 9.69 ± 2.04 mm2; p = 0.032). MAS was associated with ΔDML (β = 0.336; p < 0.001) and ΔDSL (β = 0.238; p = 0.015). ΔWFR remained significant for ΔDML (β = 1.314; p < 0.001) and ΔDSL (β = 1.371; p = 0.001), improving adjusted R2 from 0.251 to 0.370 for ΔDML and from 0.142 to 0.253 for ΔDSL. Findings remained directionally consistent when MAS was modeled as an ordered category. Complementary mixed-effects models using raw bilateral latency values showed significant hemiplegic-side-by-MAS interactions for both DML (β = 0.425; 95% CI 0.275 to 0.575; p < 0.001) and DSL (β = 0.366; 95% CI 0.195 to 0.537; p < 0.001). Conclusions: In chronic stroke hemiplegia, median nerve latencies and wrist morphology may differ between sides. Wrist flexor spasticity and side-to-side increases in WFR may be independently associated with greater latency asymmetry. These interlimb latency differences should be interpreted as physiological markers of side-to-side median nerve involvement at the wrist rather than as stand-alone diagnostic criteria for carpal tunnel syndrome.

Peripheral nerve injuries significantly impair quality of life due to limited regenerative capacity, which is affected by factors such as neuroma formation, injury severity, scarring, and comorbidities. The Muscle-in-Vein (MIV) repair technique, consisting of a vein filled with skeletal muscle fibers, has emerged as a promising alternative to nerve autografts. This approach supports regeneration by providing growth factors, guiding axonal growth, enhancing Schwann cell migration, and limiting scar and neuroma formation. However, its clinical use is currently restricted mainly to short gaps in sensory digital nerves, and the biological mechanisms underlying its effectiveness remain incompletely understood. In this study, we investigated the role of muscle fibers in the early phases of nerve regeneration, with a particular focus on vascularization. An 8 mm gap in rat median nerves was repaired using the MIV technique and analyzed at 3, 7, 14, and 21 days post-injury. Immunofluorescence analysis demonstrated complete macrophage infiltration and well-organized vascularization throughout the entire graft as early as 7 days post-injury. Consistently, RNA sequencing at early time points revealed significant enrichment of pathways associated with vascular development and identified key angiogenesis-related genes. Notably, our findings indicate partial anastomosis between vessels originating from the nerve stumps and those within the muscle component of the graft. These results suggest that the success of muscle-in-vein nerve repair strategy may be due to an early vascularization process mediated by the synergistic contribution of both muscle and vein.