Uso do laser de baixa potência para o tratamento de parestesia: uma revisão de literatura / Use of low-level laser to treat paresthesia: a literature review

Introdução: A parestesia é uma neuropatia que afeta a função sensorial. O Laser de Baixa Potência (LBP), por sua vez, apresenta propriedades analgésicas, bioestimuladoras e reparadoras. Objetivo: Realizar um levantamento na literatura científica sobre os aspectos gerais e benefícios do LBP no manejo terapêutico da parestesia, além de identificar a classificação e métodos de obtenção do diagnóstico desta condição. Materiais e Métodos: Tratou-se de uma revisão narrativa da literatura através da busca nas plataformas PubMed, SciELO, LILACS e Google Schoolar. Após o cruzamento dos descritores com os operadores booleanos e aplicação dos critérios de inclusão/exclusão, 26 estudos foram incluídos. Resultados: A parestesia pode ser classificada em neuropraxia, axonotmese e neurotmese, subdivididas em Grau I ao V. Seu diagnóstico pode ser executado através de testes subjetivos e objetivos. O LBP compreende em um dispositivo tecnológico com efeitos analgésico, anti-inflamatório e fotobiomodulador, que estimula o reparo neural. Os estudos mostram que a dosimetria nos comprimentos de onda vermelho e infravermelho, aplicação intra e extra oral, e com mais de uma sessão semanal exerce efeito modulatório positivo do reparo neural, com retorno progressivo da atividade sensitiva. Além disso, os estudos trazem uma ampla variação no número de pontos de aplicação, bem como no tempo de irradiação e quantidade de sessões, em virtude da extensão e tempo de diagnóstico da parestesia. Considerações finais: Apesar da alta complexidade da parestesia, o LBP exerce efeitos benéficos através do retorno da sensibilidade parcial ou total, além de ser um dispositivo bem tolerado pelo organismo e minimamente invasivo.

Introduction: Paresthesia is a neuropathy that affects sensory function. The Low-Level Laser (LLL), in turn, has analgesic, biostimulating and reparative properties. Purpose: Carry out a survey at the scientific literature on the general aspects and benefits of LLL in the therapeutic management of paresthesia in addition to identifying the classification and methods for obtaining a diagnosis of this condition. Materials and Methods: It was a narrative literature review through search in platforms PubMed, SciELO, LILACS and Google Schoolar. After crossing the descriptors with boolean operators and applying the inclusion/exclusion criteria, 26 articles were included in this study. Results: Paresthesia can be classified into neuropraxia, axonotmesis and neurotmesis, subdivided into Grades I to V. Its diagnostic can be carried out through subjective and objective tests. The LLL consists in a technological device with analgesic, anti-inflammatory and photobiomodulatory effects, which stimulates neural repair. Studies show that LLL in dosimetry at red and infrared wavelengths with intra and extra oral application and with more than one-week use exerts a positive modulatory effect on neural repair, with a progressive return of sensory activity. Furthermore, the studies show a wide variation in the number of application points, as well as the irradiation time and number of sessions, due to the extent and time of diagnosis of paresthesia. Final Considerations: Despite the high complexity of paresthesia, the LLL has beneficial effects through the return of partial or total sensitivity in addition being a device well tolerated by the body and minimally invasive.

Two-color fluorescence-guided surgery for head and neck cancer resections.

Significance: Head and neck squamous cell carcinoma (HNSCC) has the sixth highest incidence worldwide, with > 650,000 cases annually. Surgery is the primary treatment option for HNSCC, during which surgeons balance two main goals: (1) complete cancer resection and (2) preservation of normal tissues to ensure post-surgical quality of life. Unfortunately, these goals are not synergistic, where complete cancer resection is often limited by efforts to preserve normal tissues, particularly nerves, and reduce life-altering comorbidities. Aim: Currently, no clinically validated technology exists to enhance intraoperative cancer and nerve recognition. Fluorescence-guided surgery (FGS) has successfully integrated into clinical medicine, providing surgeons with real-time visualization of important tissues and complex anatomy, where FGS imaging systems operate almost exclusively in the near-infrared (NIR, 650 to 900 nm). Notably, this spectral range permits the detection of two NIR imaging channels for spectrally distinct detection. Approach: Herein, we evaluated the utility of spectrally distinct NIR nerve- and tumor-specific fluorophores for two-color FGS to guide HNSCC surgery. Using a human HNSCC xenograft murine model, we demonstrated that facial nerves and tumors could be readily differentiated using these nerve- and tumor-specific NIR fluorophores. Results: The selected nerve-specific fluorophore showed no significant difference in nerve specificity and off-target tissue fluorescence in the presence of xenograft head and neck tumors. Co-administration of two NIR fluorophores demonstrated successful tissue-specific labeling of nerves and tumors in spectrally distinct NIR imaging channels. Conclusions: We demonstrate a comprehensive FGS tool for cancer resection and nerve sparing during HNSCC procedures for future clinical translation.

Obturator canal block: an anatomical study.

BACKGROUND: Different approaches to the obturator nerve have been described. However, few have focused on the injection point inferior the iliopubic ramus, specifically at the exit of the obturator canal. This study aims to anatomically evaluate the ultrasound-guided obturator nerve block at the exit of the obturator canal, detailing anatomical landmarks and solution distribution. METHODS: This anatomical study was conducted using 10 cadavers to generate 20 hemipelvis samples. Ultrasound references were utilized to identify the obturator canal, iliopubic ramus, pectineus and external obturator muscles, and the obturator membrane. An ultrasound-guided obturator nerve block was performed using a low-frequency convex probe for initial identification and a high-frequency linear transducer for the injection of a methylene blue solution. Subsequent dissections were performed to evaluate the distribution of the dye within the obturator nerve. RESULTS: The injection of methylene blue consistently stained the common trunk and anterior branch of the obturator nerve in 100% of the cases and the posterior branch in 80% of the samples. Intrapelvic staining was observed in 65% of the specimens, indicating effective diffusion of the dye. Key anatomical landmarks, such as the iliopubic ramus and the obturator membrane, were crucial for accurate identification and injection. CONCLUSION: In conclusion, sagittal approaches using the iliopubic ramus as an anatomical reference achieve the most complete obturator nerve block. Our anatomical study details the structures of the obturator canal and access to the obturator nerve at its exit. Future studies are needed to confirm its safety and efficacy.

Whole-body MRI-based long-term evaluation of pediatric NF1 patients without initial tumor burden with evidence of newly developed peripheral nerve sheath tumors.

BACKGROUND: Patients with neurofibromatosis type 1 (NF1) can develop plexiform neurofibromas (PN). Large tumor burden is a predictor for the development of malignant peripheral nerve sheath tumors. Whole-body magnetic resonance imaging (WB-MRI) is the recommended imaging method for the evaluation of PN. WB-MRI is recommended for NF1 patients at transition from adolescence to adulthood. In the absence of internal PN further follow-up WB-MRI is not considered necessary. PN are often detected in early childhood, leading to the assumption that they may be congenital lesions. It remains unclear whether this invariably applies to all patients or whether patients who initially displayed no tumors can still develop PN over time. Therefore, we retrospectively reviewed WB-MRI scans of pediatric patients with NF1 without initial tumor burden and compared these with long-term follow-up scans for presence of newly developed PN. METHODS: We retrospectively reviewed WB-MRI scans of 17 NF1-children (twelve male; median age at initial scan: 9 [IQR 6.1-11.9] years) who initially displayed no PN. MRI scans with a follow-up interval of at least 6 years (median follow-up interval: 9 [IQR 5.6-12.4] years) were reviewed in consensus by two radiologists regarding the development of new PN over time. RESULTS: New PN were identified in two out of 17 children without initial tumor burden in follow-up examinations. One of these two patients developed two larger distinct PN of 4.5 cm on the right upper arm and of 2.5 cm on the left thoracic wall between the age of ten and twelve. The second child developed multiple smaller PN along the major peripheral nerves between the age of eleven and 16. In addition, 15 of the children without initial tumor burden did not develop any distinct tumors for a period of at least 6 years. CONCLUSION: Our results indicate that PN can be newly detected in pediatric patients over time, even if no PN were detected on initial MRI scans. Therefore, it seems reasonable to perform at least a second MRI in pediatric NF1 patients at transition to adulthood, even if they did not display any tumor burden on initial MRI, and when the MRI was performed significantly under the age of 18. With this approach, tumors that may have developed between scans can be detected and patients at risk for complications can be identified.

Is anterior transposition of the ulnar nerve necessary for post-traumatic elbow stiffness? A retrospective study.

OBJECTIVE: To explore whether anterior transposition of the ulnar nerve is necessary in patients with post-traumatic elbow stiffness. METHOD: This was a retrospective study of 177 patients with post-traumatic elbow stiffness treated at Shandong Provincial Hospital from 1 January 2012 to 31 October 2022. Sixty-one patients presented with ulnar nerve symptoms, and 116 patients had no nerve symptoms. Outcomes between patients with and without symptoms were compared using a range of clinical measures, namely range of motion (ROM), ulnar nerve symptoms, and various standardized scoring systems, namely, the Mayo Elbow Performance Score (MEPS), visual analog scale (VAS), improved Broberg and Morrey Score (BMS), Quick disabilities of the Arm, Shoulder, and Hand (DASH) score, Oxford Elbow Score (OES), and Amadio score. RESULTS: Open elbow release surgery significantly improved elbow joint function in patients with post-traumatic elbow stiffness, regardless of the presence of ulnar nerve symptoms. Patients with ulnar nerve symptoms showed significant improvement after anterior transposition compared with in situ release. For patients without ulnar nerve symptoms, there was no significant difference in outcomes between the two types of ulnar nerve surgery. CONCLUSION: Anterior transposition of the ulnar nerve is preferable for patients with ulnar nerve symptoms, while the choice between anterior transposition and in situ release can be individualized for patients without symptoms, based on intraoperative findings.

Risk factors for recovery from oculomotor nerve palsy after aneurysm surgery: a meta-analysis.

Background: Risk factors for recovery from oculomotor nerve palsy (ONP) after aneurysm surgery explored by meta-analysis. Methods: The PubMed, Embase, web of science, Cochrane library, China Knowledge, Wan fang, and VIP databases were searched for case-control or cohort studies on risk factors of oculomotor nerve palsy recovery after aneurysm surgery, with a cut-off date of 14 February 2024, and data were analyzed using Stata 15. Result: A total of 12 articles involving 866 individuals were included, meta-analysis results suggesting that gender (OR = 0.75, 95% CI [0.51-1.10]), age (OR = 1.00, 95% CI [0.93-1.07]), aneurysm size (OR = 0.85, 95% CI [-0.71 to 1.01]), treatment time (OR = 1.01, 95% CI [0.91-1.13]) is not a risk factor for recovery of motor nerve palsy after aneurysm surgery. Preoperative complete ONP (OR = 2.27, 95% CI [1.07-4.81]), surgery (OR = 9.88, 95% CI [2.53-38.57]), subarachnoid hemorrhage (OR = 1.29, 95% CI [1.06-1.56]) is a risk factor for recovery of motor nerve palsy after aneurysm surgery. Conclusion: Based on the results of the studies we included, we found that complete ONP before surgery led to poorer recovery, but patients with post-operative and subarachnoid hemorrhage had better recovery.

Incidence and Etiology of Rare Saphenous Nerve Injury After Knee Surgery with Adductor Canal Block: A Retrospective Observational Study.

Background: Adductor canal block (ACB) is commonly included in multimodal analgesia regimens for knee surgery. Nonetheless, the incidence, etiology, and procedure-specific risk of saphenous nerve injury after knee surgery with ACB have not been established. Purpose: We sought to identify the risk of saphenous nerve injury during knee surgery with ACB. Methods: We conducted a retrospective cohort study of patients at a single institution who underwent elective knee surgery with ultrasound-guided ACB between January 1, 2014, and December 31, 2018, and had subsequent saphenous nerve injury. The primary outcome was the incidence of saphenous nerve injury within 3 months of surgery, by surgical type and approach. Secondary outcomes included attribution of the most likely etiology and clinical outcome of the injury. Results: In 28,196 cases of knee surgery with ACB, we identified 18 cases (0.06%) of saphenous nerve injury. The most common surgery associated with saphenous nerve injury was anterior cruciate ligament (ACL) reconstruction with autograft (8/18 cases); 3 cases of injury were seen after TKA, 2 after medial patellofemoral ligament reconstruction, 2 after arthroscopy/meniscal surgery, and 1 after patellar fixation. The most likely etiology of nerve injury was attributed to ACB in 5 of 18 cases (28%) and to non-ACB cause in 13 of 18 (72%). Prognosis was rated as unknown in 11 of 18, poor in 2 of 18, favorable in 3 of 18, and full recovery in 2 of 18. Conclusions: This 5-year retrospective, single-institution cohort study found a low overall incidence of saphenous nerve injury after knee surgery with ACB, but the injury likelihood varied based on surgery and approach. Although not statistically significant, ACL reconstruction with hamstring autograft and ACB performed for postoperative rescue analgesia were most frequently associated with nerve injury.

TSPO deficiency promotes the progression of malignant peripheral sheath tumors by regulating the G2/M phase of the cell cycle via CDK1.

Malignant peripheral nerve sheath tumors (MPNSTs) are highly aggressive Schwann cell-derived sarcomas that are sporadic or associated with Neurofibromatosis 1 (NF1) gene mutations. Traditional therapies are usually ineffective for treating MPNSTs, so new targets need to be identified for the treatment of MPNSTs. In the present study, the role of the mitochondrial translocator protein (TSPO) in the regulation of cell proliferation and the cell cycle in MPNSTs was investigated. TSPO expression was lower in MPNSTs than in NFs. Loss-of-function experiments revealed that TSPO deficiency promoted MPNST cell growth, migration, and invasion and influenced the cell cycle in vitro and in vivo. In addition, TSPO depletion suppressed cell apoptosis by downregulating the expression of caspase-3, caspase-8, HSP60, p27, p53, and BCL-2 and suppressed the cell cycle by upregulating CDK1, CDK2, CCNB1 and CCNA2. Furthermore, CDK1 was determined to be an upstream target of TSPO-mediated regulation via RNA-seq, qPCR, and Western blotting. Specifically, depletion of CDK1 weakened the effect of TSPO deficiency on cell proliferation and migration. More importantly, CDK1 knockdown induced significant cell cycle arrest in the G2/M phase. In summary, TSPO deficiency regulates the cell cycle in MPNSTs by targeting CDK1, which may be an effective molecular target for prognosis evaluation and treatment.

Cardiac arrest during alveolar recruitment manoeuvre under general anaesthesia for laparoscopic surgery.

A 67-year-old woman with no history of cardiovascular disease, undergoing an elective laparoscopic cholecystectomy, experienced severe bradycardia and cardiac arrest immediately following an alveolar recruitment manoeuvre under general anaesthesia. Prompt cardiopulmonary resuscitation restored cardiac output within 2-3 min. Postoperatively, she remained stable and was discharged following 24 h of monitoring. The cardiac arrest was likely triggered by vagal nerve stimulation and activation of intrinsic cardiac reflexes by the alveolar recruitment manoeuvre. The event emphasises a rare, but significant, risk of the routine management of pulmonary atelectasis.

Midline sacral meningeal cysts: Neurophysiology abnormalities and their correlation with pelvic sensory and visceral symptoms.

BACKGROUND AND PURPOSE: Midline sacral meningeal cysts (MSMCs) are cerebrospinal fluid-filled dural diverticula. Although widely considered asymptomatic, cases involving voiding difficulties or pain have been reported. The aims of this study were, firstly, to describe the clinical presentation of patients with symptomatic MSMCs, secondly, to assess the impact of the cyst on nerve root function, and, thirdly, to assess whether nerve root injury is more frequent in patients with MSMCs than those with Tarlov cysts (TCs). METHODS: Consecutive patients with MSMCs presenting with at least one pelvic symptom participated in a cross-sectional review of symptoms using validated questionnaires. Findings of pelvic neurophysiology (pudendal sensory evoked potentials, sacral dermatomal sensory evoked potentials, external anal sphincter electromyography) and urodynamic testing were collected retrospectively. The relationship between neurophysiology, magnetic resonance imaging findings and patients' symptoms were assessed using Fisher's and analysis of variance tests. Neurophysiology findings were compared with those of TC patients. RESULTS: Eleven female patients were included (mean age 42.3 ± 12.4 years). All reported urinary symptoms. Back pain (91%), radicular leg pain (91%), bowel symptoms (45%) and sexual dysfunction (75%) were also frequently reported. Nine patients (82%) had abnormal findings on neurophysiology; three patients (27%) had one abnormal test, and six (55%) had two abnormal tests. Patients with MSMCs were more likely to have at least two abnormal neurophysiology test results compared to TC patients (55% vs. 18%, respectively; p = 0.018). CONCLUSION: Our results indicate that MSMCs are indeed associated with injury to the sacral somatic innervation when symptomatic. MSMCs are more likely to cause sacral nerve root damage compared to TCs.

Therapeutic effect of Marrubium vulgare L. Aqueous extract on chronic constriction injury of sciatic nerve-induced neuropathic pain in mice.

Marrubium vulgare L. leaves have long been recognised in Moroccan traditional medicine for their effectiveness in managing pain and inflammation. However, their potential is in treating peripheral neuropathic pain. This study aimed to investigate the effects of M. vulgare aqueous extract (AEMV) on peripheral neuropathic pain induced by chronic constriction injury (CCI) of the sciatic nerve in mice. This research represents the first exploration of AEMV's therapeutic potential in neuropathic pain management. AEMV was initially analysed using HPLC MS/MS to identify its predominant compound, Marrubiin. Mice underwent CCI surgery to induce neuropathic pain. AEMV was administered orally and Clomipramine served as a positive control. Chronic administration of AEMV significantly attenuated thermal, mechanical, and cold sensitivity induced by CCI. It also promoted functional and histological recovery of the sciatic nerve.

Development and in vitro assessment of injectable, adhesive, and self-healing chitosan-based hydrogels for treatment of spinal cord injury.

Injured spinal cords have a limited ability to regenerate because of the inhibitory environment formed in situ that affects neuronal regrow. Ensuring stable contact between the injuried nerves to support neural regeneration in the lesion microenvironment remains a significant challenge. To address this challenge, we have engineered a new injectable and adhesive hydrogel to treat spinal cord injuries. This hydrogel was produced by functionalizing chitosan with catechol groups and crosslinking it with different amounts of ß-glycerophosphate to obtain adhesive hydrogels with tunable mechanical properties. The softest hydrogel (G' ~ 300 Pa) demonstrated strong adhesion to different biological soft tissues, including porcine skin (adhesion strength of 3.4 ± 0.9 kPa) and spinal cord, as well as injectability and self-healing abilities, making it ideal for a minimally invasive administration in difficult-to-reach areas. Additionally, this composition promoted the attachment, viability, proliferation, and the expression of neuronal marker ß-III tubulin (Tuj-1) by the neuroblastoma SH-SY5Y cells. Moreover, SH-SY5Y cells cultured on the hydrogel modulated its mechanical properties (G' ~ 3500 Pa). In summary, we propose a material that is compatible with different therapies for soft tissue healing, including repairing injured nerve tissue.

Severe subacute onset sensorimotor polyneuropathy associated with brentuximab vedotin treatment for refractory classical Hodgkin's lymphoma.

A man in his 30s with a history of refractory classical Hodgkin's lymphoma presented with subacute onset asymmetric sensory disturbance, and severe weakness affecting his right more than left hand. Symptom onset was 18 weeks after commencing brentuximab vedotin (BV) treatment, an anti-CD30 antibody drug-conjugate for relapsed/refractory classical Hodgkin's lymphoma. Symptoms progressed to his lower limbs with distal sensory loss, gait imbalance, bilateral foot drop and mild proximal leg weakness. He was globally areflexic. Neurophysiology revealed a mildly asymmetric, non-length dependent, motor >sensory polyradiculoneuropathy, with mixed axonal and demyelinating features. Extensive laboratory work-up, lumbar puncture and MRI of the brachial plexus, brain, spine and chest were unremarkable. Treatment with plasma exchange, followed by intravenous immunoglobulin, resulted in objective clinical improvement 4 weeks after. BV is a potent antimicrotubule agent, thus well known to cause a length-dependent sensory axonal polyneuropathy. Demyelinating polyneuropathy, with more prominent motor involvement, in association with BV is much rarer.

Successful cutaneous sensory blockade following single-injection and double-injection techniques of ultrasound-guided superficial parasternal intercostal plane block: a randomized clinical trial.

BACKGROUND: While superficial parasternal intercostal plane blocks can improve analgesia after cardiac surgery, the optimal site and the number of injections remain uncertain. This study aimed to compare the efficacy of single versus double injections of superficial parasternal blocks, hypothesizing that double injections would achieve superior cutaneous sensory blockade. METHODS: 70 cardiac patients undergoing median sternotomy were randomly assigned to receive either single or double injections of superficial parasternal blocks bilaterally. Each patient received 40 mL of 0.25% bupivacaine with epinephrine 5 µg/mL and dexamethasone 10 mg. The single-injection group received 20 mL/side at the third costal cartilage, while the double-injection group received 10 mL/injection at the second and fourth costal cartilages. The primary outcome was a successful block, defined as sensory loss in the T2-T6 dermatomes. Secondary outcomes included sensory block of T1, T7, and T8 dermatomes, block-related complications, intraoperative hemodynamics, postoperative pain intensity, opioid consumption, and recovery quality. RESULTS: Double injections achieved an overall higher success rate compared with the single-injection technique (81% vs 51%, relative risk 1.6; 95% CI 1.2, 2.0; p<0.001). Additionally, higher blockade percentages were observed in dermatomes T1 (83% vs 59%, p=0.003), T7 (67% vs 46%, p=0.017), and T8 (61% vs 39%, p=0.011) with double injections. Other secondary outcomes did not differ significantly between groups. CONCLUSIONS: Compared with single injection, double injections of superficial parasternal blocks provided more reliable coverage of the T2-T6 dermatomes, crucial for median sternotomy. However, no differences were observed in intraoperative hemodynamic effects or postoperative pain control after cardiac surgery. TRIAL REGISTRATION NUMBER: TCTR20230408004.

Consensus recommendations for an integrated diagnostic approach to peripheral nerve sheath tumors arising in the setting of Neurofibromatosis type 1 (NF1).

Consensus recommendation published in 2017 histologically defining atypical neurofibromatous neoplasm of uncertain biologic potential (ANNUBP) and malignant peripheral nerve sheath tumor (MPNST) were codified in the 2021 WHO Classification of Tumors of the Central Nervous System and the 2022 WHO Classification of Tumors of Soft Tissue and Bone. However, given the shift in diagnostic pathology toward the use of integrated histopathologic and genomic approaches, the incorporation of additional molecular strata in the classification of Neurofibromatosis Type 1 (NF1)-associated peripheral nerve sheath tumors should be formalized to aid in accurate diagnosis and early identification of malignant transformation to enable appropriate intervention for affected patients. To this end, we assembled a multi-institutional expert pathology working group as part of a "Symposium on Atypical Neurofibroma: State of the Science". Herein, we provide a suggested framework for adequate interventional radiology and surgical sampling, and recommend molecular profiling for clinically or radiologically worrisome non-cutaneous lesions in patients with NF1 to identify diagnostically-relevant molecular features, including CDKN2A/B inactivation for ANNUBP, as well as SUZ12, EED, or TP53 inactivating mutations, or significant aneuploidy for MPNST. We also propose renaming "low-grade MPNST" to "ANNUBP with increased proliferation" to avoid the use of the "malignant" term in this group of tumors with persistent unknown biologic potential. This refined integrated diagnostic approach for NF1-associated peripheral nerve sheath tumors should continue to evolve in concert with our understanding of these neoplasms.

[Research Progress in Neurogram and Neuro-Immune Interaction of Joints in the Case of Osteoarthritis].

The joints have abundant sensory nerves and sympathetic nerve fibers,which convert physical and chemical stimuli in the joints into nerve impulses that are transmitted to the central nervous system and participate in the hypersensitivity reactions of inflammatory joint diseases such as osteoarthritis (OA).This paper summarizes the distribution and functional characteristics of intra-articular nerves and focuses on the mechanism of the vagus-sympathetic autonomic circuit in regulating the immune microenvironment in joints in the case of OA.In addition,intra-articular inflammatory cytokines represented by tumor necrosis factor-α and interleukin-6 directly or indirectly induce sensory nerve action potential and activate the pain transduction pathway from the local joint to the central nervous system.The sensory nerves in the joints in the case of OA are also involved in the recruitment of immune cells and inflammatory cytokines.This neuro-immune interaction model not only provides a variety of new targets for the treatment of OA but also suggests that the treatment of OA should adopt a holistic view with comprehensive consideration of the nerve and immune microenvironment in the bone and joint and their mutual influences.

Preoperative geniohyoid muscle mass in esophageal cancer patients is associated with swallowing function after esophagectomy.

Aim: Dysphagia often develops after esophagectomy. The geniohyoid muscle is involved in swallowing movements, but its significance in esophagectomy patients remains unclear. We investigated the relationship of preoperative geniohyoid muscle mass with post-esophagectomy swallowing function. Methods: We retrospectively analyzed 114 patients who underwent esophagectomy and gastric conduit reconstruction for esophageal malignancy. We evaluated preoperative geniohyoid muscle sagittal cross-sectional areas (cm2) using computed tomography. Median values for each sex were considered as cutoff values. Dysphagia severity was assessed using the Penetration-Aspiration Scale (PAS) during video-fluoroscopic swallowing studies performed 7-10 days postoperatively. Results: The cross-sectional area was significantly larger in males than in females (3.2 ± 0.7 vs. 2.4 ± 0.5, p < 0.01: median in males: 3.2 cm2, and in females: 2.3 cm2). These values were used to define high and low cross-sectional area groups. The cross-sectional area correlated positively with grip strength (correlation coefficient (CC) = 0.530) and skeletal muscle index (CC = 0.541). Transthyretin levels (22.4 ± 6.8 vs. 25.4 ± 5.5, p = 0.03) and cross-sectional area (2.6 ± 0.7 vs. 3.2 ± 0.8, p < 0.01) were significantly lower in patients with (PAS score ≥6; 20%) than in those without aspiration during fluoroscopic swallowing studies. Recurrent laryngeal nerve palsy was significantly more frequent in those with than in those without aspiration during fluoroscopic studies (22% vs. 5%, p = 0.03). In the multivariate analysis, low cross-sectional area and recurrent laryngeal nerve palsy were both independent risk factors for aspiration during swallowing studies (odds ratio = 3.6, p = 0.03 and odds ratio = 6.6, p = 0.02, respectively). Conclusion: Preoperative geniohyoid muscle mass, evaluated using neck computed tomography, can predict dysphagia after esophagectomy.

Alginate Use in Orthopedics and Peripheral Nerve Repair: A Systematic Review.

The use of alginate, a derivative of seaweed, has been proposed for multiple orthopedic indications. We aimed to review the current use of alginate in orthopedics and to focus on the future applications of alginate for peripheral nerve repair. A comprehensive literature search was performed to identify biomechanical, laboratory, animal, and human studies where alginate has been utilized for orthopedic or nerve repair indications. A systematic review of orthopedic indications was conducted for safety and efficacy, and a specific focus was placed on alginate for use in peripheral nerve repair and reconstruction. Thirty-two studies were identified. Alginate has a strong history and safety profile for usage in orthopedic surgery. Its primary usage has been for the repair of articular cartilage, although it has also been used for disc regeneration of the lumbar spine and for cushioning joints in osteoarthritis. The primary indication in peripheral nerve repair is to create an environment that encourages Schwann cell migration and repair in nerve injuries while blocking fibrotic scar tissue formation by inhibiting the activity of fibroblasts. Alginate hydrogel may serve as a potential conduit for nerve regeneration in nerve injuries with small to medium-sized gaps.

Early and Late Intrinsic Hand Muscle Reinnervation After End-to-Side AIN to Ulnar Motor Nerve Transfer.

BACKGROUND: The "supercharge" end-to-side (SETS) anterior-interosseous-nerve (AIN) to ulnar-motor nerve transfer is used to improve intrinsic muscle recovery in cases of severe ulnar nerve compression or proximal axonotmetic injuries. Previous work has found differing intrinsic muscle recovery after this transfer. The objectives of this study were to examine the patterns of recovery in first dorsal interossei (FDI) and abductor digiti minimi (ADM) and the impact of AIN transfer to a specific fascicular location on the ulnar-motor nerve. METHODS: A retrospective review of one fellowship-trained surgeon's consecutive patients at a single center from December 2019 to September 2021 was conducted. Patients who had an AIN to ulnar-motor nerve transfer for any indication were included and were excluded if they had less than 9 months follow-up. RESULTS: Seventeen patients were included (88% male, mean age 55 ± 14 years). At early follow-up, compound muscle action potential amplitudes for ADM and FDI did not increase. Compound muscle action potential amplitude for ADM significantly increased at late follow-up (P < .01). Average British Medical Research Council (BMRC) strength increased at early follow-up for FDI (P < .05), but not ADM. The proportion of patients with BMRC ≥ 3 increased for FDI (P < .01) and ADM (P < .05) at late follow-up. Volar-ulnar AIN insertion position did not have a clear effect on outcomes. CONCLUSIONS: The SETS AIN to ulnar-motor nerve transfer demonstrates clinical and electrophysiologic evidence of intrinsic muscle recovery and reinnervation, with differing recovery of outcomes. The role of specific fascicular targeting is still unclear and required further examination as does the mechanism behind differing intrinsic recovering.

Ultra-High Frequency Spinal Nerve Neuromodulation for Improving Bladder Continence: Implications for Overactive Bladder Management.

OBJECTIVE: Ultrahigh frequencies (UHF) have been shown to selectively suppress the sensory pathway with a rapid onset and prolonged effect compared with low frequencies. Few studies have explored the feasibility of UHF electrical stimulation in treating overactive bladder. This study aimed to investigate whether bladder overactivity could be inhibited by UHF stimulation at the L6 nerve root. MATERIALS AND METHODS: Female Sprague-Dawley rats (n = 12) were divided into two groups: sham and UHF groups. Bladder overactivity was induced by continuous intravesical infusion of 0.5% acetic acid (AA). UHF L6 nerve root stimulation (500 kHz, 20 mA for 5 minutes) was applied to the rats in the UHF group. To investigate the effects of the treatment, intravesical pressure was recorded by cystometrography during continuous transvesical infusion, with volume threshold (VT) and intercontraction interval (ICI) used to conduct the investigation. RESULTS: Bladder overactivity was successfully developed in all rats with a significant decrease of median VT and ICI to 83.7% and 86.4%, respectively. UHF stimulation of the L6 nerve root was able to counteract the AA effect by significantly increasing median VT and ICI to 220% and 36.1%, respectively; these effects persisted for ≥two hours. There was a significant difference in the effects of UHF electrical stimulation between the sham and UHF groups (p < 0.05). CONCLUSION: This preliminary study provides evidence for UHF stimulation of the L6 spinal nerve root, analogous to the sacral nerve root in humans, as a potential alternative neuromodulation technique to suppress bladder overactivity.