Investigating the effects of dopamine on short- and long-latency afferent inhibition.

Short- and long-latency afferent inhibition (SAI and LAI respectively) are phenomenon whereby the motor evoked potential induced by transcranial magnetic stimulation (TMS) is inhibited by a sensory afferent volley consequent to nerve stimulation. It remains unclear whether dopamine participates in the genesis or modulation of SAI and LAI. The present study aimed to determine if SAI and LAI are modulated by levodopa (l-DOPA). In this placebo-controlled, double-anonymized study Apo-Levocarb (100 mg l-DOPA in combination with 25 mg carbidopa) and a placebo were administered to 32 adult males (mean age 24 ± 3 years) in two separate sessions. SAI and LAI were evoked by stimulating the median nerve and delivering single-pulse TMS over the motor hotspot corresponding to the first dorsal interosseous muscle of the right hand. SAI and LAI were quantified before and 1 h following ingestion of drug or placebo corresponding to the peak plasma concentration of Apo-Levocarb. The results indicate that Apo-Levocarb increases SAI and does not significantly alter LAI. These findings support literature demonstrating increased SAI following exogenous dopamine administration in neurodegenerative disorders. KEY POINTS: Short- and long-latency afferent inhibition (SAI and LAI respectively) are measures of corticospinal excitability evoked using transcranial magnetic stimulation. SAI and LAI are reduced in conditions such as Parkinson's disease which suggests dopamine may be involved in the mechanism of afferent inhibition. 125 mg of Apo-Levocarb (100 mg dopamine) increases SAI but not LAI. This study increases our understanding of the pharmacological mechanism of SAI and LAI.

A randomized trial to determine the minimum effective lidocaine volume for median nerve block using hydrodissection.

Ultrasound-guided hydrodissection with 5% dextrose in water (DW5) creates a peri-nervous compartment, separating the nerve from the neighboring anatomical structures. The aim of this randomized study was to determine the minimum volume of lidocaine 2% with epinephrine 1:200,000 required when using this technique to achieve an effective median nerve block at the elbow in 95% of patients (MEAV95). Fifty-two patients scheduled for elective hand surgery received an ultrasound-guided circumferential perineural injection of 4 ml DW5 and an injection of local anesthetic (LA) following a biased coin up-and-down sequential allocation method. A successful block was defined as a light touch completely suppressed on the two distal phalanges of the index finger within a 30-min evaluation period. The MEAV95 of lidocaine 2% with epinephrine was 4 ml [IQR 3.5-4.0]. Successful median nerve block was obtained in 38 cases (82.6%) with median onset time of 20.0 [10.0-21.2] minutes (95% CI 15-20). The analgesia duration was 248 [208-286] minutes (95% CI 222-276). Using an ultrasound-guided hydrodissection technique with DW5, the MEAV95 to block the median nerve at the elbow with 2% lidocaine with epinephrine was 4 ml [IQR 3.5-4.0]. This volume is close to that usually recommended in clinical practice.Trial registration clinicaltrials.gov. NCT02438657, Date of registration: May 8, 2015.

Tocotrienol-Rich Vitamin E (Tocovid) Improved Nerve Conduction Velocity in Type 2 Diabetes Mellitus Patients in a Phase II Double-Blind, Randomized Controlled Clinical Trial.

Diabetic peripheral neuropathy (DPN) is the most common microvascular complication of diabetes that affects approximately half of the diabetic population. Up to 53% of DPN patients experience neuropathic pain, which leads to a reduction in the quality of life and work productivity. Tocotrienols have been shown to possess antioxidant, anti-inflammatory, and neuroprotective properties in preclinical and clinical studies. This study aimed to investigate the effects of tocotrienol-rich vitamin E (Tocovid SuprabioTM) on nerve conduction parameters and serum biomarkers among patients with type 2 diabetes mellitus (T2DM). A total of 88 patients were randomized to receive 200 mg of Tocovid twice daily, or a matching placebo for 12 months. Fasting blood samples were collected for measurements of HbA1c, renal profile, lipid profile, and biomarkers. A nerve conduction study (NCS) was performed on all patients at baseline and subsequently at 2, 6, 12 months. Patients were reassessed after 6 months of washout. After 12 months of supplementation, patients in the Tocovid group exhibited highly significant improvements in conduction velocity (CV) of both median and sural sensory nerves as compared to those in the placebo group. The between-intervention-group differences (treatment effects) in CV were 1.60 m/s (95% CI: 0.70, 2.40) for the median nerve and 2.10 m/s (95% CI: 1.50, 2.90) for the sural nerve. A significant difference in peak velocity (PV) was also observed in the sural nerve (2.10 m/s; 95% CI: 1.00, 3.20) after 12 months. Significant improvements in CV were only observed up to 6 months in the tibial motor nerve, 1.30 m/s (95% CI: 0.60, 2.20). There were no significant changes in serum biomarkers, transforming growth factor beta-1 (TGFß-1), or vascular endothelial growth factor A (VEGF-A). After 6 months of washout, there were no significant differences from baseline between groups in nerve conduction parameters of all three nerves. Tocovid at 400 mg/day significantly improve tibial motor nerve CV up to 6 months, but median and sural sensory nerve CV in up to 12 months of supplementation. All improvements diminished after 6 months of washout.

Cortical somatosensory processing after botulinum toxin therapy in post-stroke spasticity.

ABSTRACT: In dystonic and spastic movement disorders, abnormalities of motor control and somatosensory processing as well as cortical modulations associated with clinical improvement after botulinum toxin A (BoNT-A) treatment have been reported, but electrophysiological evidence remains controversial. In the present observational study, we aimed to uncover central correlates of post-stroke spasticity (PSS) and BoNT-A-related changes in the sensorimotor cortex by investigating the cortical components of somatosensory evoked potentials (SEPs). Thirty-one chronic stroke patients with PSS of the upper limb were treated with BoNT-A application into the affected muscles and physiotherapy. Clinical and electrophysiological evaluations were performed just before BoNT-A application (W0), then 4 weeks (W4) and 11 weeks (W11) later. PSS was evaluated with the modified Ashworth scale (MAS). Median nerve SEPs were examined in both upper limbs with subsequent statistical analysis of the peak-to-peak amplitudes of precentral P22/N30 and postcentral N20/P23 components. At baseline (W0), postcentral SEPs were significantly lower over the affected cortex. At follow up, cortical SEPs did not show any significant changes attributable to BoNT-A and/or physiotherapy, despite clear clinical improvement. Our results imply that conventional SEPs are of limited value in evaluating cortical changes after BoNT-A treatment and further studies are needed to elucidate its central actions.

Ultrasound-guided corticosteroid injection for patients with carpal tunnel syndrome: a systematic review and meta-analysis of randomized controlled trials.

Carpal tunnel syndrome (CTS) refers to the symptoms and signs caused by the compression of the median nerve in the carpal tunnel. It can be treated by corticosteroid injection into the carpal tunnel. Two methods for injection have been employed, namely ultrasound-guided and landmark-guided injection. This systematic review and meta-analysis was conducted to compare these methods in terms of several outcomes. A search of the PubMed, Cochrane Library, and Embase databases was performed from the date of their inception to October 7, 2020 to identify randomized controlled trials (RCTs). Results for continuous variables are expressed as standardized mean differences (SMDs) with 95% confidence intervals (CIs). Analyses were performed using RevMan 5.3 software. The analysis included eight RCTs published between 2013 and 2019 with a total of 448 patients. Ultrasound-guided injection yielded more favorable results than landmark-guided injection for the Boston Carpal Tunnel Syndrome Questionnaire, Symptom Severity Scale [SMD = - 0.43, 95% CI (- 0.68, - 0.19), P = 0.0005] and Boston Carpal Tunnel Syndrome Questionnaire, Functional Status Scale [SMD = - 0.50, 95% CI (- 0.84, - 0.15), P = 0.005]. Ultrasound-guided corticosteroid injection is recommended for patients with CTS.

Prognostic factors in carpal tunnel syndrome treated with 5% dextrose perineural injection: A retrospective study.

Background: Perineural injection therapy with 5% dextrose water (D5W) is a potential and innovative treatment with long-term efficacy for carpal tunnel syndrome (CTS). However, the prognostic factors of this management are lacking; hence, the aim of this retrospective study was to identify the prognostic factors of D5W perineural injection therapy for mild-to-moderate CTS. Methods: A total of 52 patients (52 wrists) diagnosed with mild-to-moderate CTS and treated with a single ultrasound-guided 5cc D5W perineural injection were retrospectively reviewed. Patient-reported injection outcomes (visual analog scale, VAS) at 6 months post-injection were categorized into two groups; (1) Good outcome, when symptom relief ≥50% compared to pre-injection and (2) Poor outcome, when symptom relief < 50% compared to pre-injection. Significant variables between groups were entered into a binary logistic regression with forward stepwise regression to determine the prognostic factors for these outcomes. Results: The treatment outcome was significantly related to body height and sensory nerve conduction velocity (SNCV) (159.1 ± 1.0 vs. 155.0 ± 1.8, p=0.04; 33.6 ± 0.8 vs. 28.3 ± 1.2, p=0.001, good vs. poor outcomes). However, only SNCV remained significantly correlated with the outcomes after conducting stepwise logistic regression (ORs: 1.201; 95% CI 1.05-1.38; p=0.01). Conclusions: SNCV was found to be a significant prognostic factor of treatment outcome for patients with mild-to-moderate CTS 6 months after a D5W perineural injection.

Change to movement and morphology of the median nerve resulting from steroid injection in patients with mild carpal tunnel syndrome.

There are conflicting hypotheses regarding the initial pathogenesis of carpal tunnel syndrome (CTS). One hypothesis characterizes it as inflammation of the median nerve caused by compression, while another hypothesis characterizes CTS as non-inflammatory fibrosis of the subsynovial connective tissue (SSCT). This study aimed to investigate the differences in the ultrasonography parameters before and after a steroid injection, which is effective for CTS, to elucidate the initial pathogenesis of CTS and the mechanisms of action of the injected steroid. Fourteen hands from 14 healthy participants and 24 hands from 24 participants with mild CTS were examined. Dynamic movement and morphology of the median nerve before and after steroid injection were measured. There was no significant difference in the normalized maximal distance of the median nerve, which reflects the degree of fibrosis in the SSCT indirectly, during finger and wrist movements before and after the injection among patients with CTS (p > 0.05). Among the parameters that indirectly reflects the degree of median nerve compression, such as normalized maximal change in the aspect ratio of the minimum-enclosing rectangle (MER), maximal change in the median nerve perimeter, and maximal value of the median nerve cross-sectional area (CSA), statistically significant differences were not observed between values of the normalized maximal change in the aspect ratio of the MER and maximal change in the median nerve perimeter, during finger and wrist movements recorded before and after the injection in patients with CTS (p > 0.05). However, multivariate logistic regression analysis revealed that the change in the normalized maximal value of the median nerve CSA, according to finger and wrist movement was correlated with the administration of the steroid injection (p < 0.05). In conclusion, compared to that noted before steroid injection, the median nerve CSA noted during finger and wrist movements changed significantly after injection in patients with mild CTS. Given the improvement in median nerve swelling after steroid injection, but no improvement in the movement of the median nerve during finger and wrist movements, median nerve swelling due to compression (rather than fibrosis of the SSCT may be the initial pathogenesis of early-stage (mild) CTS, and the fibrous changes around the median nerves (SSCT) may be indicative of secondary pathology after median nerve compression. Further studies are required to validate the findings of our study and confirm the pathogenesis of CTS.

Comparison of Corticosteroid Injection Dosages in Mild to Moderate Idiopathic Carpal Tunnel Syndrome: A Randomized Controlled Trial.

OBJECTIVES: To evaluate whether the therapeutic effect of ultrasound-guided injections with 10 mg or 40 mg triamcinolone acetonide (TA) was dose-dependent in patients with idiopathic mild to moderate carpal tunnel syndrome (CTS). DESIGN: Prospective, double-blind, randomized controlled study with 12 weeks of follow-up. SETTING: Rehabilitation outpatient clinic of a single medical center. PARTICIPANTS: Patients with CTS (N=56). INTERVENTION: Participants were randomly assigned to 2 treatment groups for injection: (A) 40 mg TA+2% lidocaine hydrochloride or (B) 10 mg TA+2% lidocaine hydrochloride. MAIN OUTCOME MEASURES: Participants were evaluated using visual analog scale (VAS) and Boston Carpal Tunnel Questionnaire (BCTQ, including Symptom Severity Scale [SSS] and Functional Status Scale [FSS]) at baseline and 6 and 12 weeks after injection). Nerve conduction studies, including parameters of distal motor latency, amplitude of compound motor action potential, amplitude of sensory nerve action potential and sensory nerve conduction velocity of median nerve, and the patient's subjective impression of improvement, were recorded before injection and 6 and 12 weeks after injection. RESULTS: No significant differences were observed in baseline demographic characteristics and clinical evaluations. The parameters in group A and B at baseline, 6 weeks, and 12 weeks were (1) SSS: 2.17±0.14, 1.19±0.04, and 1.34±0.09 and 1.87±0.11, 1.21±0.07, and 1.26±0.04; (2) FSS: 1.63±0.07, 1.27±0.06, and 1.33±0.08 and 1.50±0.10, 1.18±0.05, and 1.26±0.05; (3) VAS: 6.4±0.3, 2.2±0.3, and 3.0±0.1 and 6.7±0.3, 2.0±0.3, and 3.1±0.3, respectively, and significantly decreased after 6 and 12 weeks in both treatment groups (P<.05). All parameters of nerve conduction studies improved in both groups after 12 weeks (P<.05). VAS, BCTQ, and nerve conduction studies did not show significant intergroup differences after 6 and 12 weeks. CONCLUSION: In patients with idiopathic mild to moderate CTS, ultrasound-guided injection with 10 and 40 mg TA yield similar improvements in BCTQ, VAS, and nerve conduction studies at the 12-week follow-up.

Motor excitability measurements in early stage familial amyloid polyneuropathy: The influence of tafamidis treatment.

OBJECTIVE: To test motor fiber excitability in early affected patients with transthyretin (TTR)-type familial amyloid polyneuropathy (TTR-FAP) before and during tafamidis treatment. METHODS: We examined the left median nerve of 21 healthy-matched controls and 10 early affected TTR-FAP patients using the automated threshold-tracking program, QTRAC. TTR-FAP patients were tested one day before the initiation of tafamidis treatment, 3 and 6 months later. RESULTS: The drug was well-tolerated in all patients; there was no drop-out. No statistical difference was found between healthy controls and TTR-FAP patients at study entry. On treatment, both stimulus intensity for 50% of the maximal motor response and rheobase increased significantly from entry to the last evaluation at 6 months (P<0.05). Strength duration time constant decreased significantly from the 3rd to the 6th month of evaluation (P<0.05). There was also a "fanning-out" effect on the late depolarization phase (TEd 90-100ms) as well as a shortened relative refractory period from study entry to the 6th month of evaluation. CONCLUSIONS: Threshold-tracking of median nerve motor fibers is not a helpful technique for the early diagnosis of TTR-FAP patients. Tafamidis was well-tolerated. We observed possible membrane hyperpolarization during treatment. Threshold tracking can contribute to documenting the action of new drugs to treat neuropathies. Tafamidis may change nerve electrical properties by reducing the burden of amyloid fibrils.

Carpal tunnel syndrome and associated nail changes: Review and examples from the author's practice.

Carpal tunnel syndrome (CTS) is commonly seen by general practitioners and often presents with neurologic symptoms of nocturnal pain and paresthesia along the median nerve distribution. Approximately 20% of patients also present with cutaneous findings (ulcerations, blistering, sclerodactyly, nail dystrophy) characterizing a severe form called necrotic CTS. Necrotic CTS can also be associated with bone changes (acro-osteolysis). In the author's practice, combined nail and skin findings are not an uncommon presentation of CTS, although this form remains overlooked and underreported in the dermatological textbooks and studies. This manuscript aims to review the literature on CTS cases, with a specific focus on using associated nail findings as diagnostic clues. The literature review along with a few additional recent cases from the author's practice demonstrate that CTS is frequently accompanied by a variety of nail changes including koilonychia, longitudinal fissuring, Beau's lines, onychomadesis, melanonychia, nail thickening, hyperkeratosis, and ischemic ulcerations with paronychia. Furthermore, when these changes are limited to the second and third fingernails, they should prompt the diagnosis of CTS. Once suspected, diagnostic evaluation is not difficult and surgical management can resolve cutaneous findings and prevent irreversible changes such as acro-osteolysis.

A randomized controlled trial: comparing extracorporeal shock wave therapy versus local corticosteroid injection for the treatment of carpal tunnel syndrome.

PURPOSE: Extracorporeal shock wave therapy (ESWT) has been reported as a new therapy for carpal tunnel syndrome (CTS). However, few studies have compared ESWT with the local corticosteroid injection (LCI). METHODS: In this study, a randomized controlled trial comparing 30 patients with ESWT and 25 patients treated with LCI was conducted. The clinical outcomes were obtained with tests including the visual analog scale (VAS) for pain and paresthesia, the Boston Carpal Tunnel Questionnaire (BQ), and a nerve conduction study, before the study started and at three, nine, and 12 weeks after the start of the treatment. RESULTS: Significantly greater improvement in the VAS and BQ scores was noted for the ESWT group than for the LCI group (P < 0.05). For the nerve conduction study, there was a significant improvement in the median nerve sensory nerve action potential distal latency at the nine and 12-week follow-ups for the ESWT group. CONCLUSIONS: ESWT is a useful noninvasive short-term treatment for mild to moderate carpal tunnel syndrome and elicits a better recovery than LCI does, but more research is needed to test the clinical outcomes of ESWT.

Polydeoxyribonucleotide injection in the treatment of patients with carpal tunnel syndrome: Retrospective preliminary study.

BACKGROUND: Corticosteroid injection is beneficial in treating carpal tunnel syndrome (CTS) due to its anti-inflammatory effects. However, its side effects limit widespread usage. Recently, several studies have found that polydeoxyribonucleotide offers anti-inflammatory capabilities with fewer side effects, making it an ideal alternative. Nevertheless, there has been no study on its effectiveness in patients with CTS. Therefore, we evaluate the effectiveness of polydeoxyribonucleotide in patients with CTS. Based on the criteria, 30 patients with CTS who received two-consecutive polydeoxyribonucleotide injections (with a week interval) were initially included. METHOD: Patients with CTS were investigated retrospectively. To evaluate the effectiveness of polydeoxyribonucleotide in patients with CTS, numeric rating scale (NRS), cross-sectional area (CSA) of the median nerve, and severity and functional status scores of CTS based on the Boston Carpal Tunnel Syndrome Questionnaire (BCTQ) were assessed. RESULTS: There was a significant improvement in the NRS, CSA, and functional and severity scores of BCTQ after two-consecutive polydeoxyribonucleotide injections (P < .05). CONCLUSION: In conclusion, although more research is needed to evaluate the effectiveness of polydeoxyribonucleotide in patients with CTS, the findings here suggest that polydeoxyribonucleotide may be a viable alternative to corticosteroids in patients with CTS.

Severe hyperhomocysteinemia and peripheral neuropathy as side effects of nitrous oxide in two patients with sickle cell disease.

Nitrous oxide (N2O) is a widely used anesthetic agent. We report two patients with sickle cell disease (SCD) who presented with complications following the use of N2O. Patient 1, a 15-year-old girl, presented severe hyperhomocysteinemia, pancytopenia, vitamin B12 deficiency, and peripheral polyneuropathy after massive use of N2O for pain management. At the 1-year follow-up, hyperhomocysteinemia and B12 deficiency had resolved, but she had persisting mild symptoms of polyneuropathy. Patient 2, a 17-year-old boy, presented only severe hyperhomocysteinemia, only partially corrected by initial B12 supplementation. Careful monitoring of N2O use, especially in patients with SCD, is mandatory to prevent complications.

The Use of a Hypoallergenic Dermal Matrix for Wrapping in Peripheral Nerve Lesions Regeneration: Functional and Quantitative Morphological Analysis in an Experimental Animal Model.

INTRODUCTION: The aim of this research was to test, in an animal model, the nerve regeneration technique with a hypoallergenic acellular dermal matrix used to wrap the microsurgical neural suture. MATERIALS AND METHODS: Two groups of rats received the cut of limb right median nerves. The regeneration technique considers for both groups an end-to-end nerve suture. In the experimental group (A) was used also a wrapping protocol by a conduit of collagen matrix currently used in oral surgery. The animals underwent functional grasping tests (at 1, 3, 5, and 7 months) and a histological and quantitative analysis of distal nerve was performed at the end of experimental time. RESULT: After seven months, the grasping test reveals functional recovery in each tested animal; this improvement is more evident in Group A. The fibers appear well organized with restored myelin sheaths in both groups. Group A showed a great quantity of connective tissue surrounding the nerve. The quantitative morphology analysis in both groups shows a similar fibers density, fiber diameter, and myelin thickness. The differences between the groups in axon mean diameter are significant. In Group A M/d, D/d, and g-ratio is significantly higher compared to control group. CONCLUSIONS: Histological and functional assessments show a functional recovery of the injured nerve in the test groups, stressed by the results of the grasping tests and the meaningful increasing in fiber diameter and higher g-ratio. Moreover, a connective tissue cuff distinguishes the distal portion of the injured nerve. Considering the easy availability and handling of the material used in this study we can conclude that this experimental technique can be considered as a valid alternative to protect nerves in nerve wrap surgery.

Liraglutide treatment reduced interleukin-6 in adults with type 1 diabetes but did not improve established autonomic or polyneuropathy.

AIMS: Type 1 diabetes can be complicated with neuropathy that involves immune-mediated and inflammatory pathways. Glucagon-like peptide-1 receptor agonists such as liraglutide, have shown anti-inflammatory properties, and thus we hypothesized that long-term treatment with liraglutide induced diminished inflammation and thus improved neuronal function. METHODS: The study was a randomized, double-blinded, placebo-controlled trial of adults with type 1 diabetes and confirmed symmetrical polyneuropathy. They were randomly assigned (1:1) to receive either liraglutide or placebo. Titration was 6 weeks to 1.2-1.8 mg/d, continuing for 26 weeks. The primary endpoint was change in latency of early brain evoked potentials. Secondary endpoints were changes in proinflammatory cytokines, cortical evoked potential, autonomic function and peripheral neurophysiological testing. RESULTS: Thirty-nine patients completed the study, of whom 19 received liraglutide. In comparison to placebo, liraglutide reduced interleukin-6 (-22.6%; 95% confidence interval [CI]: -38.1, -3.2; P = .025) with concomitant numerical reductions in other proinflammatory cytokines. However neuronal function was unaltered at the central, autonomic or peripheral level. Treatment was associated with -3.38 kg (95% CI: -5.29, -1.48; P < .001] weight loss and a decrease in urine albumin/creatinine ratio (-40.2%; 95% CI: -60.6, -9.5; P = .02). CONCLUSION: Hitherto, diabetic neuropathy has no cure. Speculations can be raised whether mechanism targeted treatment, e.g. lowering the systemic level of proinflammatory cytokines may lead to prevention or treatment of the neuroinflammatory component in early stages of diabetic neuropathy. If ever successful, this would serve as an example of how fundamental mechanistic principles are translated into clinical practice similar to those applied in the cardiovascular and nephrological clinic.

New basic insights on the potential of a chitosan-based medical device for improving functional recovery after radical prostatectomy.

OBJECTIVES: To evaluate: (i) the neuro-regenerative potential of chitosan membrane (CS-Me) on acutely axotomised autonomic neurones in vitro; (ii) to exclude the possibility that a pro-regenerative biomaterial could interfere with the proliferation activity of prostate cancer cell lines; (iii) to provide an in vivo proof of the biocompatibility and regeneration promoting effect of CS-Me in a standardised rat model of peripheral nerve injury and repair; (iv) finally, to evaluate the tissue reaction induced by the degrading material; as previous studies have shown promising effects of CS-Me for protection of the neurovascular bundles for potency recovery in patients that undergo nerve-sparing radical prostatectomy (RP). MATERIALS AND METHODS: Addressing aim (i), the neuro-regenerative potential, organotypic cultures derived from primary sympathetic ganglia were cultured on CS-Me over 3 days and neurite extension and axonal sprouting were evaluated. Addressing aim (ii), effects of CS on cancer cells, different human prostate cancer cell lines (PC3, DU-145, LN-Cap) were seeded on CS-coated plates or cultured in the presence of CS-Me dissolution products. Addressing aims (iii) and (iv), functional recovery of peripheral nerve fibres and tissue reaction with the biomaterial, CS-Me and CS nerve guides were used to repair a median nerve injury in the rat. Functional recovery was evaluated during the post-recovery time by the behavioural grasping test. RESULTS: CS-Me significantly stimulated axon elongation from autonomic ganglia in comparison to control conditions in organotypic three-dimensional cultures. CS coating, as well as the dissolution products of CS-Me, led to a significantly lower proliferation rate of prostate cancer cell lines in vitro. Tissue reaction towards CS-Me and standard CS nerve guides was similar in the rat median nerve model, as was the outcome of nerve fibre regeneration and functional recovery. CONCLUSION: The results of this study provide the first experimental evidence in support of the clinical safety of CS-Me and of their postulated effectiveness for improving functional recovery after RP. The presented results are coherent in demonstrating that acutely axotomised autonomic neurones show increased neurite outgrowth on CS-Me substrate, whilst the same substrate reduces prostate cancer cell line proliferation in vitro. Furthermore, CS-Me do not demonstrate any disadvantage for peripheral nerve repair in a standard animal model.

The Effectiveness of Ultrasound-Guided Steroid Injection Combined with Miniscalpel-Needle Release in the Treatment of Carpal Tunnel Syndrome vs. Steroid Injection Alone: A Randomized Controlled Study.

OBJECTIVES: Carpal tunnel syndrome (CTS) is one of the most common nerve entrapment syndromes, which has a serious impact on patients' work and life. The most effective conservative treatment is steroid injection but its long-term efficacy is still not satisfactory. The aim of this study was to evaluate the effectiveness of steroid injection combined with miniscalpel-needle (MSN) release for treatment of CTS under ultrasound guidance versus steroid injection alone. We hypothesized that combined therapy could be more beneficial. METHODS: Fifty-one patients with CTS were randomly allocated into two groups, namely, steroid injection combined with MSN release group and steroid injection group. The therapeutic effectiveness was evaluated using Boston Carpal Tunnel Questionnaire (BCTQ), cross-sectional area (CSA) of the median nerve, and four electrophysiological parameters, including distal motor latency (DML), compound muscle action potential (CMAP), sensory nerve action potential (SNAP), and sensory nerve conduction velocity (SNCV) at baseline, 4 and 12 weeks after treatment. RESULTS: Compared with baseline, all the parameters in both groups showed statistically significant improvement at week 4 and week 12 follow-up, respectively (P<0.05). When compared with steroid injection group, the outcomes including BCTQ, DML, CMAP, SNCV, and CSA of the median nerve were significantly better in steroid injection combined with MSN release group at week 12 after treatment (P<0.05). CONCLUSIONS: The effectiveness of steroid injection combined with MSN release for CTS is superior to that of steroid injection alone, which may have important implications for future clinical practice. This Chinese clinical trial is registered with ChiCTR1800014530.

Ultrasound-Guided Hydroneurolysis of the Median Nerve for Recurrent Carpal Tunnel Syndrome.

BACKGROUND: Recurrent carpal tunnel syndrome is often associated with perineural scarring around the median nerve. Surgical options include relatively invasive procedures, such as fat pad grafting, ligament reconstruction, muscle transfer, and nerve wraps. All have limited success because of the possibility of repeated recurrent scarring postoperatively. METHODS: We discuss a technique involving injection with external hydroneurolysis of the median nerve under ultrasound guidance for recurrent carpal tunnel. Injection enables a gentler dissection of the surrounding tissues compared with open external neurolysis, with less chance of recurrent scarring. This technique is a unique alternative to repeat operative intervention in recurrent carpal tunnel, as well as a prelude to repeat open decompression and salvage procedures. RESULTS: Ultrasound-guided injection with external hydroneurolysis of the median nerve is a safer, more limited procedure compared with repeat open surgery, usually performed in an office setting. This procedure limits risk, anesthesia, and operating/recovery room expenses, offering relief in 70% to 80% of cases. Furthermore, in the 20% to 30% of patients with inadequate relief, surgery remains a viable option. US provides important information on the anatomy of the median nerve and carpal canal and can rule out covert pathology. CONCLUSIONS: We offer an alternative treatment for recurrent carpal tunnel syndrome, a difficult problem for which many surgeons recommend nonoperative treatment. US provides objective data concerning residual nerve compression and allows for dynamic assessment. Theoretically, this also offers a viable solution for surgeons and their patients with recurrent carpal tunnel syndrome before being pressed to consider repeat open surgery.

Cross-sectional area of the median nerve after intraneural vs perineural low volume administration. / Evaluación del área de sección del nervio mediano tras la inyección intraneural o perineural.

INTRODUCTION: To recognise the relationship between the needle tip and the median nerve during peripheral nerve block is of interest to avoid neural damage. However, signs of intraneural injection are not clearly established. The aim of this study was to define the changes observed in the peripheral nerve after the intraneural or perineural administration of 1ml of solution. MATERIAL AND METHODS: Ultrasound guided median nerve blocks were performed in the forearm of 10 fresh cadavers on 60 occasions (3 per forearm). They were randomised into the intraneural (n=30) or perineural (n=30) location of the needle tip, after the consensus of location by 7 specialists. After 1ml of solution was injected an evaluation was made of the changes in the cross-sectional area of the nerve, as well as the displacement along the nerve. RESULTS: The cross-sectional area of the median nerve was increased in both groups, however, the increase was significantly higher in the intraneural group (perineural 0.007±0.013cm2 vs. intraneural 0.032±0.021cm2, P<.0001). An increase of more than 27% of the area ensures an intraneural injection in the median nerve according to the ROC curve analysis. Both proximal and distal diffusion were observed more frequently in the intraneural group (proximal: 86% vs 14%, P<.0001, Distal: 43% vs 4%, P<.0001). CONCLUSIONS: Based on this experimental study, it is concluded that the injection of a small volume (1ml) allows to discriminate the disposition of the intraneural vs perineural needle in a high percentage of cases. Therefore, it is suggested that this "dose test" should be considered in the safety algorithms if it is required to reduce the incidence of intraneural injection.

Nerve hydrodissection for carpal tunnel syndrome: A prospective, randomized, double-blind, controlled trial.

INTRODUCTION: In this study we explored the efficacy of nerve hydrodissection for mild-to-moderate carpal tunnel syndrome (CTS). METHODS: Thirty-four participants were randomly assigned to an intervention group or a control group. One 5-ml dose of normal saline was injected into the intracarpal and subcutaneous regions in subjects of both groups, respectively. The primary outcome measure was the Boston Carpal Tunnel Syndrome Questionnaire (BCTQ) score. Secondary outcomes were cross-sectional area of the median nerve and electrophysiological studies. Assessments were performed before the injection and at 1, 2, 3, and 6 months postintervention. RESULTS: Compared with the control group, the intervention group showed significantly greater improvement at the second and third posttreatment months according to BCTQ severity score and at all time-points for cross-sectional area of the median nerve (P < 0.01). DISCUSSION: Our study demonstrates the therapeutic effects of nerve hydrodissection for mild-to-moderate CTS. Muscle Nerve 59:174-180, 2019.