The Effect of Liraglutide on Axon Regeneration and Functional Recovery after Peripheral Nerve Lesion.

Peripheral nerve injuries inflict severe consequences, necessitating innovative therapeutic strategies. This study investigates the potential of liraglutide, a glucagon-like peptide-1 receptor agonist, in mitigating the consequences of peripheral nerve injury. The existing treatment methods for such injuries underscore the importance of ongoing translational research efforts. Thirty adult Wistar rats underwent sciatic nerve dissection and repair surgery. The nerves were surgically transected using micro scissors at a precise location located 1.5 cm proximal to the trifurcation site. The study included a control group and two experimental groups, one treated with saline (placebo group) and the other with liraglutide (experimental group) for 12 weeks. Motor function, electromyography (EMG), and biochemical and histopathological analyses were performed after 12 weeks of treatment. Electrophysiological assessments revealed that liraglutide improved the compound muscle action potential (CMAP) amplitude and motor function compared to the saline-treated group. Histological and immunohistochemical analyses demonstrated increased NGF expression, total axon number, and diameter and reduced fibrosis in the liraglutide group. Biochemical analyses illustrated liraglutide's antioxidative properties, evidenced by reduced malondialdehyde (MDA) levels. Galectin-3 levels were suppressed and GDF-11 levels were modulated by liraglutide, indicating anti-inflammatory and anti-apoptotic effects. Liraglutide is a promising therapeutic intervention for peripheral nerve injuries, promoting functional recovery and histopathological improvement. Its multifaceted positive impact, beyond glycemic control, suggests constructive effects on the acute and chronic inflammatory processes associated with peripheral neuropathy. These findings warrant further research to elucidate molecular mechanisms and facilitate clinical translation. The study contributes valuable insights to the growing understanding of GLP-1 receptor agonists' neuroprotective properties in the context of peripheral nerve injuries.

Consecutive assessment of recovery after peripheral nerve injury of the sciatic nerve within the same rat using PET/MRI.

BACKGROUND: Positron emission tomography (PET) has been reported as effective in diagnosing peripheral nerve injury (PNI). However, there is a lack of studies evaluating different degrees of PNI using PET within the same individual to reduce errors due to interindividual differences. PURPOSE: To evaluate the recovery process in the same rat after sciatic nerve injury using PET/magnetic resonance imaging (MRI). MATERIAL AND METHODS: Crushing nerve injuries were induced in the left sciatic nerves of six male rats, preserving the right ones. The degree of nerve damage was measured at one, two, three, four, and five weeks postoperatively using three assessment methods: paw withdrawal threshold test (RevWT); PET (SUVR); and MRI (MRSIR). All the representing values of each method are presented as ratio values of the right and left sides in each rat. RESULTS: Significant gradual recovery of all rats was observed over time in all the methods. No significant differences in RevWT and MRSIR were observed between before and more than four weeks after injury, whereas a significant difference in SUVR was still observed between before and five weeks after injury (P = 0.0007). The parameters of all methods decreased significantly over time (P = 0.000, all), and the explanatory power was significant in RevWT, SUVR, and MRSIR. CONCLUSION: PET and MRI could be valuable non-invasive techniques for diagnosing neuropathic pain resulting from PNI. PET/MRI would be expected to be a more accurate and informative diagnostic tool for PNI than MRI alone.

Enhancing nerve regeneration in infraorbital nerve injury rat model: effects of vitamin B complex and photobiomodulation.

Orofacial nerve injuries may result in temporary or long-term loss of sensory function and decreased quality of life in patients. B vitamins are required for DNA synthesis and the repair and maintenance of phospholipids. In particular, vitamins B1, B6, and B12 are essential for neuronal function. Deficiency in vitamin B complex (VBC) has been linked to increased oxidative stress, inflammation and demyelination. Photobiomodulation (PBM) has antioxidant activity and is neuroprotective. In addition, a growing literature attests to the positive effects of PBM on nerve repair. To assess the effect of PBM and VBC on regenerative process we evaluated the expression of brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), myelin basic protein (MBP), laminin and neurofilaments (NFs) using Western blotting to identify regenerative pattern after chronic constriction injury of the infraorbital nerve (CCI IoN) treated by PBM, VBC or its combination. After CCI IoN, the rats were divided into six groups naive, sham, injured (CCI IoN), treated with photobiomodulation (904 nm, 6.23 J/cm2, CCI IoN + PBM), treated with VBC (containing B1, B6 and B12) 5 times, CCI IoN + VBC) and treated with PBM and VBC (CCI IoN + VBC + PBM). The treatments could revert low expression of BDNF, MBP and laminin. Also reverted the higher expression of neurofilaments and enhanced expression of NGF. PBM and VBC could accelerate injured infraorbital nerve repair in rats through reducing the expression of neurofilaments, increasing the expression of BDNF, laminin and MBP and overexpressing NGF. These data support the notion that the use of PBM and VBC may help in the treatment of nerve injuries. This finding has potential clinical applications.

Neurotropin® accelerates peripheral nerve regeneration in a rat sciatic nerve crush injury model.

BACKGROUND: Peripheral nerve injuries are common and serious conditions. The effect of Neurotropin® (NTP), a nonprotein extract derived from the inflamed skin of rabbits inoculated with vaccinia virus, on peripheral nerve regeneration has not been fully elucidated. However, it has analgesic properties via the activation of descending pain inhibitory systems. Therefore, the current study aimed to determine the effects of NTP on peripheral nerve regeneration. METHODS: We examined axonal outgrowth of dorsal root ganglion (DRG) neurons using immunocytochemistry in vitro. In addition, nerve regeneration was evaluated functionally, electrophysiologically, and histologically in a rat sciatic nerve crush injury model in vivo. Furthermore, gene expression of neurotrophic factors in the injured sciatic nerves and DRGs was evaluated. RESULTS: In the dorsal root ganglion neurons in vitro, NTP promoted axonal outgrowth at a concentration of 10 mNU/mL. Moreover, the systemic administration of NTP contributed to the recovery of motor and sensory function at 2 weeks, and of sensory function, nerve conduction velocity, terminal latency, and axon-remyelination 4 weeks after sciatic nerve injury. In the gene expression assessment, insulin-like growth factor 1 and vascular endothelial growth factor expressions were increased in the injured sciatic nerve 2 days postoperatively. CONCLUSIONS: Therefore, NTP might be effective in not only treating chronic pain but also promoting peripheral nerve regeneration after injury.

Therapeutic Effect of an Ursolic Acid-Based Nutraceutical on Neuronal Regeneration after Sciatic Nerve Injury.

Peripheral nerve injuries lead to severe functional impairments and long recovery times, with limited effectiveness and accessibility of current treatments. This has increased interest in natural bioactive compounds, such as ursolic acid (UA). Our study evaluated the effect of an oleolyte rich in UA from white grape pomace (WGPO) on neuronal regeneration in mice with induced sciatic nerve resection, administered concurrently with the induced damage (the WGPO group) and 10 days prior (the PRE-WGPO group). The experiment was monitored at two-time points (4 and 10 days) after injury. After 10 days, the WGPO group demonstrated a reduction in muscle atrophy, evidenced by an increased number and diameter of muscle fibers and a decreased Atrogin-1 and Murf-1 expression relative to the denervated control. It was also observed that 85.7% of neuromuscular junctions (NMJs) were fully innervated, as indicated by the colocalization of α-bungarotoxin and synaptophysin, along with the significant modulation of Oct-6 and S-100. The PRE-WGPO group showed a more beneficial effect on nerve fiber reformation, with a significant increase in myelin protein zero and 95.2% fully innervated NMJs, and a pro-hypertrophic effect in resting non-denervated muscles. Our findings suggest WGPO as a potential treatment for various conditions that require the repair of nerve and muscle injuries.

Ultrasound evaluation of radial nerve injuries by cortex overlapping screw tips after internal fixation of humeral fractures: a cadaveric study.

PURPOSE: The radial nerve may be painfully irritated or damaged by open reduction and internal fixation (ORIF) of humeral fractures. Secondary radial nerve lesions after ORIF of humeral shaft fractures are described in up to 16%. Not only peripheral nerves but also orthopaedic instruments and osteosynthesis material are well visible by ultrasound. The aim of this study was to evaluate the accuracy of ultrasound in assessing the relation between the bone overlapping screw tips and the radial nerve close to the humeral bone. METHODS: Ultrasound-guided drilling was used to place screws as close as possible to the radial nerve in 8 humeral bones of four cadavers. The relation between the radial nerve and the screw tips was assessed by high-resolution ultrasound, and the overlap of all screw tips over the bone was measured by ultrasound and fluoroscopy. Thereafter, the findings were validated by anatomical dissection. RESULTS: We could correctly identify all screw tips and their relation to the radial nerve by ultrasound. In 7 of 8 cases, the screw tip had direct contact with the radial nerve. The overlaying length of the screw tip was accurately measured by using ultrasound in all cases. In contrast fluoroscopy underestimated this length in 50% of cases. CONCLUSION: With this study, we show that ultrasound can reliable visualize the screw tips and its relation to the radial nerve. Ultrasound is a promising diagnostic tool to evaluate patients with radial nerve irritations or lesions after ORIF of humeral fractures. Furthermore, ultrasound could be an adequate tool to guide drilling.

Ultrasound evaluation of a new surface reference line to describe sural nerve location and safe zones to consider in posterior leg approaches.

PURPOSE: Several authors have described methods to predict the sural nerve pathway with non-proportional numerical distances, but none have proposed a person-proportional, reproducible method with anatomical references. The aim of this research is to describe ultrasonographically the distance and crossing zone between a surface reference line and the position of the sural nerve. METHODS: Descriptive cross-sectional study, performed between January and April 2022 in patients requiring foot surgery who met inclusion criteria. The sural nerve course in the posterior leg was located and marked using ultrasound. Landmarks were drawn with a straight line from the medial femoral condyle to the tip of the fibula. Four equal zones were established in the leg by subdividing the distal half of the line. This way, areas based on simple anatomical proportions for each patient were studied. The distance between the marking and the ultrasound nerve position was measured in these 4 zones, creating intersection points and safety areas. Location and distances from the sural nerve to the proposed landmarks were assessed. RESULTS: One-hundred and four lower limbs, 52 left and 52 right, assessed in 52 patients were included. The shortest median distance of the nerve passage was 2.9 mm from Point 2. The sural nerve intersection was 60/104 (57.7%) in Zone B, 21/104 (20.1%) in Zone C and 19/104 (18.3%) in Zone A. Safety zones were established. Average 80.5% of coincidence in sural nerve localization was found in the distal half of the leg, in relation to the surface reference line when comparing both legs of each patient. CONCLUSIONS: This study proposes a simple, reproducible, non-invasive and, for the first time, person-proportional method, that describes the distance and location of the main areas of intersection of the sural nerve with points and zones (risk and safe zones) determined by a line guided by superficial anatomical landmarks. Its application when surgeons plan and perform posterior leg approaches will help to avoid iatrogenic nerve injuries. LEVEL OF EVIDENCE: IV.

Iatrogenic nerve injury in primary and revision reverse total shoulder arthroplasty.

INTRODUCTION: Iatrogenic nerve injury in orthopedic surgery can impair functional outcomes. During the last years, a steady increase in the number of performed reverse total shoulder arthroplasties has been reported and complications associated with this procedure are continuously described. Neurological complications, however, remain underreported. The aims of this study were to calculate the incidence of iatrogenic nerve injury after primary and revision reverse total shoulder arthroplasty in a large patient cohort, as well as identify associated patient-and surgery-related risk factors. MATERIALS AND METHODS: A retrospective review of our institution's internal Reverse Total Shoulder Arthroplasty (RTSA) database from September 2005 to December 2019 was undertaken and 34 patients with iatrogenic nerve injuries were identified, resulting in a neurological complication rate of 2.6%. Group comparisons between patients with nerve injuries (n = 34) and the remaining cohort without nerve injuries (n = 1275) were performed to identify patient- and surgery-related risk factors. RESULTS: Of the 34 cases with iatrogenic nerve injury, damage to terminal nerve branches occurred in 21 patients, whereas a brachial plexus lesion was diagnosed in the other 13. Nerve revision surgery was necessary in four patients. At final follow-up 13 patients (45%) had residual motor deficits and 17 (59%) had residual sensory deficits. Higher numbers of previous surgeries of the affected shoulder correlated with subsequent nerve injury (p = 0.035). Operative time was significantly longer in patients, who developed a neurologic deficit, showing a correlation between duration of surgery and occurrence of nerve injury (p = 0.013). Patients with neurologic complications were significantly younger than patients without nerve damage (median 68 vs. 72 years, p = 0.017). CONCLUSIONS: In specialists' hands reverse total shoulder arthroplasty is a rather safe procedure regarding the risk of neurologic injury. However, multiple previous surgeries of the affected shoulder increase the risk of neurological complications. Cases with post-operative neurologic compromise are rare and usually recover well, with few patients suffering long-term functional deficits from iatrogenic nerve injury. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

Neuropathy following intramuscular injections: a clinical and neurophysiological study from a tertiary care centre in Pakistan.

OBJECTIVE: To assess the clinical and neurophysiological profile of peripheral nerve injuries in patients following intramuscular injections. METHODS: The descriptive, cross-sectional study was conducted at the Department of Neurology, Mayo Hospital, Lahore, Pakistan, from July 2019 to January 2021, and comprised adult patients of either gender with isolated peripheral nerve injuries following intramuscular injections. Nerve conduction studies were performed for each patient. Data was analysed using SPSS 26. RESULTS: Of the 99 patients, 59(59.6%) were males and 40(40.4%) were females. The mean age was 26.7+/-18.1 years, 34(34.3%) patients were under weight and 78(78.8%) were either illiterate or had low literacy level. Radial nerve was involved in 56(56.6%) cases, followed by sciatic in 39(39.4%) and axillary nerve 4(4.04%). Overall, 14(14.14%) injection had been administered by doctors, while the other 85(85.85%) were given by paramadics. Marked reduction in compound muscle action potential 72(72.7%) and sensory nerve action potential 82(82.8%) was noted, while re-innervation was seen in 78(78.7%). CONCLUSIONS: Intramuscular nerve injuries can be greatly minimised by spreading awareness regarding safe injection techniques and strict implementation of standard operating procedures in hospitals and clinics.

Pregabalin in patients with post-traumatic peripheral neuropathic pain: A meta-analysis of randomized controlled trials.

OBJECTIVE: The aim of the study was to investigate the safety and efficacy of pregabalin versus placebo in post-traumatic peripheral neuropathic pain (PTNP). METHODS: PubMed, Cochrane Library, Web of Science, and Google Scholar were searched for relevant evidence up to January 2022. The Cochran tool was used to assess the quality of randomized clinical trials (RCTs). Data analysis was performed using Comprehensive Meta-Analysis software. RESULTS: Three RCTs involving 821 patients were included in the meta-analysis. A significant difference was observed between pregabalin and placebo in terms of the pain score (the standardized mean difference [SMD] = -0.14, 95% CI: 0.28 to -0.006, p = 0.04) and sleep interference (MD = -0.25, 95% CI: -0.39 to -0.11, p = 0.00). There was also a significant difference between pregabalin and placebo regarding somnolence (risk ratio [RR] = 2.78; 95% CI: 1.64-4.71, p = 0.00), dizziness (RR = 4.13; 95% CI: 2.71-6.28, p = 0.00), and disturbance in attention (RR: 2.97; 95% CI: 1.02-8.65, p = 0.04). However, no significant difference was observed between pregabalin and placebo in terms of headache (RR = 1.20; 95% CI: 0.70-2.06, p = 0.50), fatigue (RR = 1.42; 95% CI: 0.82-2.47, p = 0.20), nausea (RR = 1.52; 95% CI: 0.88-2.62, p = 0.13), constipation (RR = 1.84; 95% CI: 0.78-4.29, p = 0.15), and discontinuation (RR = 1.52; 95% CI: 0.45-5.06, p = 0.49). CONCLUSION: Compared with placebo, pregabalin showed better efficacy in reducing PTNP and improving sleep interference. However, it was associated with higher adverse events. Further RCTs are needed to confirm these findings.

Creatine promotes the repair of peripheral nerve injury by affecting macrophage polarization.

The present study aimed to explore whether creatine promotes the repair of peripheral nerve injury and its possible mechanism. In vitro: RAW264.7 cells were used to investigate the role of proteins related to the JAK2/STAT1 pathway in the polarization of macrophages treated with creatine. In vivo: A sciatic nerve crush model was used. After the injury, IL-4 or creatine was injected. The recovery of motor function was assessed by the rotarod test and sciatic function index at 2, 6, 10, and 16 days after injury. At 16 days after injury, the ultrastructure of the nerve tissue was observed under a transmission electron microscope. Immunostaining were performed at 4 and 16 days to investigate the expression levels of macrophage-related markers as well as the distribution of macrophages after injury. Compared with the IFN-γ group, the group pretreated with creatine showed a significant decrease in p-JAK2 and p-STAT1 in vitro. The motor function of mice in the creatine group (CR1) and creatine 4 days group (CR2) was significantly improved compared to the control group (CON). The improvement in the CR2 group was more significant. Immunostaining showed that infiltrating macrophages mainly comprised M1 macrophages in the CON group and M2 macrophages in the CR group. Our study shows that creatine promotes the repair of peripheral nerve injury by affecting macrophage polarization, possibly through decreasing M1 polarization by inhibiting the JAK2/STAT1 pathway.

Frozen vein wrapping for chronic nerve constriction injury reduces sciatic nerve allodynia in a rat model.

BACKGROUND: Autologous vein wrapping (VW) is used in the treatment of recurrent chronic constriction neuropathy and traumatic peripheral nerve injury. However, use of autologous veins is limited by the inability to obtain longer veins of sufficient length for larger sites. Frozen allograft tissue has several advantages, including its availability for large grafts, avoidance of donor-site morbidity, and shorter operation time. Here, we investigated the effect of frozen vein wrapping (FVW) in Wistar rats as a model of sciatic nerve injury. RESULTS: The rats were grouped by treatment as (i) untreated after chronic constriction injury surgery (CCI; control group), (ii) treated with vein wrapping using freshly isolated vein (VW), and (iii) treated with vein wrapping using frozen vein (FVW). Mechanical allodynia was assessed with von Frey filaments on postoperative days (PODs) 1, 3, 5, 7, and 14. Gene expression of HO-1 was evaluated by quantitative polymerase chain reaction (qPCR). The response of heme oxygenase-1 gene, Hmox-1, expression to VW and FVW was assessed by RT-PCR. Both VW and FVW significantly increased withdrawal threshold levels compared to the untreated control group on POD 1, 3, and 5. Both VW and FVW also showed increased HO-1 expression compared to the CCI group. CONCLUSIONS: FVW increased the withdrawal threshold similar to VW in a rat CCI model for short periods. Frozen vein wrapping using vein allograft without donor site morbidity may be an alternative therapeutic option.

Failure to Compensate: Patients With Nerve Injury Use Their Injured Dominant Hand, Even When Their Nondominant Is More Dexterous.

OBJECTIVE: To identify how individuals respond to unilateral upper extremity peripheral nerve injury via compensation (increased use of the nondominant hand). We hypothesized that injury to the dominant hand would have a greater effect on hand use (left vs right choices). We also hypothesized that compensation would not depend on current (postinjury) nondominant hand performance because many patients undergo rehabilitation that is not designed to alter hand use. DESIGN: Observational survey, single-arm. SETTINGS: Academic research institution and referral center. PARTICIPANTS: A total of 48 adults (N=48) with unilateral upper extremity peripheral nerve injury. Another 14 declined participation. Referred sample, including all eligible patients from 16 months at 1 nerve injury clinic and 1 hand therapy clinic. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Hand use (% of actions with each hand) via Block Building Task. Dexterity via Jebsen-Taylor Hand Function. RESULTS: Participants preferred their dominant hand regardless of whether it was injured: hand usage (dominant/nondominant) did not differ from typical adults, regardless of injured side (P>.07), even though most participants (77%) were more dexterous with their uninjured nondominant hand (mean asymmetry index, -0.16±0.25). The Block Building Task was sensitive to hand dominance (P=2 × 10-4) and moderately correlated with Motor Activity Log amount scores (r2=0.33, P<.0001). Compensation was associated only with dominant hand dexterity (P=3.9 × 10-3), not on nondominant hand dexterity, rehabilitation, or other patient and/or injury factors (P>.1). CONCLUSIONS: Patients with peripheral nerve injury with dominant hand injury do not compensate with their unaffected nondominant hand, even if it is more dexterous. For the subset of patients unlikely to recover function with the injured hand, they could benefit from rehabilitation that encourages compensation with the nondominant hand.

Early and late apoptosis protein expression (Bcl-2, BAX and p53) in traumatic brachial plexus injury.

OBJECTIVES: This research aims to analyze the expression of pro-apoptotic proteins (Bax, p53) and anti-apoptotic protein (Bcl-2) in the nerve roots of the brachial plexus following traumatic brachial plexus injury (TBPI) in the early and late stage. METHODS: A total of 30 biopsy samples were taken from the proximal stump of the postganglionic nerve roots of the TBPI patients' brachial plexus from January 2018 until September 2019. The samples were taken from patients within six months of trauma (early stage, group A) and more than six months following trauma (late stage, group B). Bcl-2, Bax, and p53 expressions in each group were measured and compared. RESULTS: We found significant differences in the Bcl-2 (p=0.04), Bax (p<0.0001), p53 (p<0.0001) expressions between group A and B. The Bcl-2/Bax expression ratio in group A and B was 2.26 and 0.22, respectively. Meanwhile, the Bcl-2/p53 expression ratio in group A and B was 1.64 and 0.23, respectively. CONCLUSION: Apoptosis is inhibited by Bcl-2 activities in the early stage following trauma. In the late stage, a significant decrease of Bcl-2 coupled with a substantial increase of Bax and p53 indicates a continuation of the apoptotic process.

A novel approach of using brachial plexus blockade as an experimental model for diagnosis of intraoperative nerve dysfunction with somatosensory evoked potentials: a blinded proof-of-concept study.

PURPOSE: Intraoperative nerve dysfunction has been difficult to investigate because of its rarity and unpredictable occurrence. The diagnostic test attributes of nerve function monitors have not been clearly defined. This proof-of-concept study aimed to assess the feasibility of using brachial plexus blockade (BPB) in awake patients as an experimental model for nerve dysfunction to characterize the diagnostic test attributes of somatosensory evoked potentials (SSEPs). METHODS: We obtained baseline SSEPs and neurologic function in patients and subsequently placed BPBs (experimental model) to generate progressive states of nerve dysfunction. We monitored SSEP changes (index test) and neurologic symptoms (reference standard) simultaneously during the onset of BPB to determine the temporal relationships and diagnostic test attributes of SSEPs. RESULTS: Brachial plexus blockade produced differential motor and sensory dysfunction that allowed simultaneous clinical and neurophysiologic assessment. One hundred and fifty-seven pairs of multiple data points from 14 patients were included for final analysis. The onset of abnormal SSEP signals almost always preceded the onset of neurologic symptoms. The sensitivities and specificities of SSEP to detect the impairment of power (motor rating score ≤ 4/5), cold sensation, and two-point discrimination were 100% and 67%, 99% and 55%, and 100% and 46%, respectively. CONCLUSION: This study found that BPB can produce sufficient differential nerve dysfunction to allow adequate evaluation of the diagnostic test attributes of SSEPs as a nerve monitor. The results of this study may stimulate further work on refining intraoperative nerve dysfunction models and diagnostic nerve function monitors. TRIAL REGISTRATION: www.clinicaltrials.gov (NCT03409536); registered 24 January 2018.

RéSUMé: OBJECTIF: La dysfonction nerveuse peropératoire est difficile à étudier en raison de sa rareté et de son imprévisibilité. Les attributs d'un test diagnostique des moniteurs de la fonction nerveuse n'ont pas été clairement définis. Cette étude de démonstration de faisabilité visait à évaluer la faisabilité de l'utilisation d'un bloc du plexus brachial (BPB) chez des patients éveillés comme modèle expérimental de la dysfonction nerveuse afin de caractériser les attributs de test diagnostique des potentiels évoqués somesthésiques (PES). MéTHODE: Nous avons enregistré les PES et la fonction neurologique de base des patients, puis administré des BPB (modèle expérimental) pour générer des états progressifs de dysfonction nerveuse. Nous avons surveillé simultanément les changements des PES (test pour déterminer l'indicateur) et les symptômes neurologiques (norme de référence) pendant l'évolution du BPB afin de déterminer les relations temporelles et les attributs de test diagnostique des PES. RéSULTATS: Le bloc du plexus brachial a produit une dysfonction motrice et sensorielle différentielle qui nous a permis de procéder à une évaluation clinique et neurophysiologique simultanée. Cent cinquante-sept paires de points de données multiples issues de 14 patients ont été incluses pour l'analyse finale. L'apparition de signaux de PES anormaux a presque toujours précédé l'apparition de symptômes neurologiques. Les sensibilités et les spécificités des PES pour détecter la perte de force (score moteur ≤ 4/5), la sensation de froid et la discrimination à deux points étaient de 100 % et 67 %, 99 % et 55 %, et 100 % et 46 %, respectivement. CONCLUSION: Cette étude a constaté que le bloc du plexus brachial peut produire une dysfonction nerveuse différentielle suffisante pour permettre l'évaluation adéquate des attributs de test diagnostique des PES en tant que moniteur nerveux. Les résultats de cette étude pourraient motiver d'autres travaux sur l'amélioration des modèles de dysfonction nerveuse peropératoire et des moniteurs diagnostiques de la fonction nerveuse. ENREGISTREMENT DE L'éTUDE: www.clinicaltrials.gov (NCT03409536); enregistrée le 24 janvier 2018.

Communications between the superficial and deep fibular nerves in the foot: An anatomical and electrophysiological study.

INTRODUCTION: The deep fibular sensory nerve can be recorded to evaluate for peripheral nerve injury; however, it can be challenging in some individuals. Anatomic variation could account for some of this difficulty. Cadaver dissection and electrophysiological testing were used to characterize deep and superficial fibular sensory nerve supply to the foot. MATERIALS AND METHODS: Nineteen feet from 15 (8 males and 7 females) cadavers were dissected to identify the deep fibular nerves (DFNs) and superficial fibular nerves (SFNs). Sensation to the first dorsal web space was tested electrophysiologically in 101 participants (31 males and 70 females) with an age range of 18-47 years with stimulation over both DFNs and SFNs. RESULTS: Eleven of the 19 (58%) cadaver limbs had a communication between SFNs and DFNs in the dorsum of the foot. A reliable sensory response was recorded in the first dorsal web space in 88% of the limbs tested. Deep fibular stimulation alone produced a response in 34% of the limbs, while superficial fibular stimulation alone produced a response in 10% of the limbs. A separate response with stimulation of both the DFNs and SFNs was recorded in 44% of the limbs. CONCLUSIONS: A functional superficial to deep fibular sensory communication is present in a significant portion of the population. Those with the communication may not have the isolated sensory loss that would be expected in the first dorsal web space in conditions impacting the DFNs.

Comparison of two different decellularization methods for processed nerve allograft.

The use of processed nerve allografts as an alternative to autologous nerve grafts, the gold standard treatment for peripheral nerve defects, is increasing. However, it is not widely used in Korea due to cost and insurance issues. Moreover, the main detergent used in the conventional Hudson method is unavailable. Therefore, a new nerve allograft decellularization process is needed. We aimed to compare the traditional Hudson method with a novel decellularization process that may remove cellular content more efficiently while preserving the extracellular matrix (ECM) structure using low concentration sodium dodecyl sulfate (SDS) and nuclease. After each decellularization process, DNA content was measured in nerve tissue. Masson's trichrome staining and scanning electron microscopy were performed to determine the state of preservation of the ECM. A significantly greater amount of DNA content was removed in the novel method, and the ECM structure was preserved in both methods. For the in vivo study, a 15-mm long sciatic nerve defect was created in two groups of Sprague-Dawley rats, and processed nerve allografts decellularized using the Hudson or novel method were transplanted. Functional and histological recovery results were measured 12 weeks post-transplantation. Ankle contracture angle, maximal isometric tetanic force of the tibialis anterior (TA), and the TA mass were compared between the groups, as well as the percent neural tissue (100 × neural area/intrafascicular area). There was no significant difference in functional and histological nerve recovery between the methods. The novel method is appropriate for developing a processed nerve allograft.

Predictors of functional outcome after peripheral nerve injury and compression.

STUDY DESIGN: Retrospective cohort study. INTRODUCTION: Upper-extremity peripheral nerve injuries can impact long-term pain, work performance, and disability, yet there are few studies evaluating treatment outcomes for a large sample of patients with varying peripheral nerve pathology. PURPOSE OF THE STUDY: The purpose of this study was to identify outcomes of care and predictors of disability and health status in adults with peripheral nerve injuries. METHODS: We explored medical records from 364 patients treated by a plastic surgeon over a three-year period. Descriptive and inferential statistics compared the Disabilities of the Arm, Shoulder, and Hand, Short-Form 8, and routine intake data between baseline and discharge, diagnosis, and intervention group. Multivariate linear regression models predicted disability, work disability, and physical and mental health at discharge. RESULTS: We found significant improvements in disability, work disability, pain, depression, and stress. Health status changed minimally. Disability decreased most in patients who were working and who had symptoms fewer than six months. Outcomes were not statistically different between surgical and nonsurgical patients. Disability was the highest in patients with brachial plexus injuries. Multivariate models predicted 35 to 55% of the variance in the outcome measures. Factors that were highly predictive of functional outcomes included work status, household management, pain, depression, stress, and difficulty sleeping. CONCLUSIONS: Patients with peripheral nerve injuries experience improved pain and disability whether treated surgically or nonsurgically. Maintaining engagement in meaningful home and work roles may improve outcomes. Helping patients manage pain remains important, along with combatting stress, depression, and sleep deprivation.

Sural nerve harvest for infants: integrated with information based on anatomical dissections

Background/aim: The aim of the present study was to determine the course and possible variations of the sural nerve with all anatomical details in human fetal cadavers. Materials and methods: This study was performed on 60 fetal cadavers. Formation type and level of the sural nerve was detected. Results: According to trimesters, it was determined that the mean transverse and vertical distance between the lowest point of the LM and the SN varied between 1.1 and 2.9 mm and 1.54 and 3.58 mm, respectively. Type 2 was the most common seen type of sural nerve (35.83%). It was determined that the sural nerve was mostly formed at the middle third of the leg (42.5%). Conclusion: Sural nerve graft with the knowledge of the anatomical details may be used for peripheral nerve reconstruction is required in congenital lesions, such as facial paralysis, obstetric brachial paralysis, and posttraumatic lesions in infants and children.

Efficacy of electrical stimulation of denervated muscle: A multicenter, double-blind, randomized clinical trial.

BACKGROUND: This was a multicenter, double-blind, randomized clinical trial to investigate the efficacy of electrical stimulation of denervated muscle (ESDM) on recovery of patients with peripheral nerve injuries. METHODS: We enrolled 38 patients with traumatic peripheral nerve injuries with axonal damage and clinical impairment of two muscles, who were randomly treated with real or sham electrical stimulation (ES). Clinical and neurophysiological examinations were performed before treatment, at the end of treatment, and 3 mo posttreatment, by the same physician who was blinded to the ES allocation. RESULTS: All patients improved but there was no significant beneficial effect of ESDM compared with sham treatment. CONCLUSIONS: This study failed to demonstrate the efficacy of ESDM for peripheral nerve injuries. However, given the large number of variables related to ES and the heterogeneity in disease etiologies and clinical manifestations, future studies on homogeneous populations using different stimulation protocols may be useful.