Nerve Innervation Research Articles

Senescence of endplate osteoclasts induces sensory innervation and spinal pain.

Spinal pain affects individuals of all ages and is the most common musculoskeletal problem globally. Its clinical management remains a challenge as the underlying mechanisms leading to it are still unclear. Here, we report that significantly increased numbers of senescent osteoclasts (SnOCs) are observed in mouse models of spinal hypersensitivity, like lumbar spine instability (LSI) or aging, compared to controls. The larger population of SnOCs is associated with induced sensory nerve innervation, as well as the growth of H-type vessels, in the porous endplate. We show that deletion of senescent cells by administration of the senolytic drug Navitoclax (ABT263) results in significantly less spinal hypersensitivity, spinal degeneration, porosity of the endplate, sensory nerve innervation, and H-type vessel growth in the endplate. We also show that there is significantly increased SnOC-mediated secretion of Netrin-1 and NGF, two well-established sensory nerve growth factors, compared to non-senescent OCs. These findings suggest that pharmacological elimination of SnOCs may be a potent therapy to treat spinal pain.

Senescence of endplate osteoclasts induces sensory innervation and spinal pain

Spinal pain affects individuals of all ages and is the most common musculoskeletal problem globally. Its clinical management remains a challenge as the underlying mechanisms leading to it are still unclear. Here, we report that significantly increased numbers of senescent osteoclasts (SnOCs) are observed in mouse models of spinal hypersensitivity, like lumbar spine instability (LSI) or aging, compared to controls. The larger population of SnOCs is associated with induced sensory nerve innervation, as well as the growth of H-type vessels, in the porous endplate. We show that deletion of senescent cells by administration of the senolytic drug Navitoclax (ABT263) results in significantly less spinal hypersensitivity, spinal degeneration, porosity of the endplate, sensory nerve innervation, and H-type vessel growth in the endplate. We also show that there is significantly increased SnOC-mediated secretion of Netrin-1 and NGF, two well-established sensory nerve growth factors, compared to non-senescent OCs. These findings suggest that pharmacological elimination of SnOCs may be a potent therapy to treat spinal pain.

CT-guided radiofrequency ablation of facial and mandibular nerves in the treatment of compound Meige’s syndrome

This retrospective study examined the clinical outcomes and complications in 6 cases of compound Meige’s syndrome, presenting with blepharospasm and masticatory muscle spasm, following treatment with CT-guided radiofrequency ablation targeting bilateral facial nerves and mandibular branches of the trigeminal nerve. After the operation, the symptoms of eyelid spasm and masticatory muscle spasm resolved, but mild facial paralysis and numbness of mandibular nerve innervation persisted. Follow-up for 4–28 months showed that the symptoms of facial paralysis resolved within 2–5 (3.17 ± 0.94) months after the operation, whereas the numbness in the mandibular region persisted, accompanied by a decrease in masticatory function. During the follow-up period, none of the 6 patients experienced a recurrence of Meige’s syndrome. These findings suggest that CT-guided radiofrequency ablation of the bilateral facial nerve and mandibular branches of the trigeminal nerve may offer a promising approach to treating compound Meige’s syndrome.

Progressively worsening ptosis in a woman: A case report

Key Clinical MessageFiller injections into the upper eyelid may cause levator aponeurosis fibrosis and ptosis. This risk must be considered. When ptosis appears, treatment might be difficult. Understanding the upper eyelid anatomy and procedures is essential to prevent eyelid damage.AbstractPtosis is a prevalent condition in cosmetic surgery that occurs due to malfunction of the levator palpebrae superioris or insufficient Müller muscle action. It is characterized by the upper eyelid edge appearing lower than usual when seen at eye level. Ptosis may be categorized into congenital and acquired forms. The primary cause of congenital ptosis is attributed to abnormalities of the levator palpebrae superioris muscle or the motor nerve innervation that controls it. The condition arises from atypical development and malfunction of the oculomotor system. Acquired ptosis may be classified into many categories including traumatic, neurogenic, myogenic, senile, mechanical, and fake ptosis. Currently, there is little documentation of ptosis resulting from the degeneration of the aponeurosis of the muscle in the upper eyelid. We received a case of ptosis caused by fibrosis of the levator palpebrae superioris aponeurotic membrane. We used the technique of levator palpebrae superioris great advancement. The levator palpebrae superioris—Müller muscle was folded to create a stable composite construction via the levator palpebrae superioris high progress.

Cause analysis and clinical intervention of C 5 palsy after cervical surgery

To review the research progress of C 5 palsy (C 5P) after cervical surgery, providing new clinical intervention ideas for the C 5P patients. The relevant literature domestically and abroad was extensively consulted and the latest developments in the incidence, risk factors, manifestations and diagnosis, prevention, and intervention measures of C 5P were systematically expounded. C 5P is characterized by weakness in the C 5 nerve innervation area after cervical decompression surgery, manifested as limited shoulder abduction and elbow flexion, with an incidence rate more than 5%, often caused by segmental spinal cord injury or mechanical injury to the nerve roots. For patients with risk factors, careful operation and preventive measures can reduce the incidence of C 5P. Most of the patients can recover with conservative treatment such as drug therapy and physical therapy, while those without significant improvement after 6 months of treatment may require surgical intervention such as foraminal decompression and nerve displacement. Currently, there has been some advancement in the etiology and intervention of C 5P. Nevertheless, further research is imperative to assess the timing of intervention and surgical protocol.

A surgical technique for individual control of the muscles of the rabbit lower hindlimb.

Little is known regarding the precise muscle, bone and joint actions resulting from individual and simultaneous muscle activation(s) of the lower limb. An in situ experimental approach is described herein to control the muscles of the rabbit lower hindlimb, including the medial and lateral gastrocnemius, soleus, plantaris and tibialis anterior. The muscles were stimulated using nerve-cuff electrodes placed around the innervating nerves of each muscle. Animals were fixed in a stereotactic frame with the ankle angle set at 90deg. To demonstrate the efficacy of the experimental technique, isometric plantarflexion torque was measured at the 90deg ankle joint angle at a stimulation frequency of 100, 60 and 30 Hz. Individual muscle torque and the torque produced during simultaneous activation of all plantarflexor muscles are presented for four animals. These results demonstrate that the experimental approach was reliable, with insignificant variation in torque between repeated contractions. The experimental approach described herein provides the potential for measuring a diverse array of muscle properties, which is important to improve our understanding of musculoskeletal biomechanics.

Maternal High-Fat Diet Programs Development of Airway Hyperinnervation and Hyperresponsiveness In Offspring Independent of Genetic Background

HYPOTHESIS/RATIONALE: Asthma is more likely to occur in children born to obese mothers. However, understanding the mechanisms behind this increased risk has lacked genetically representative animal models. We have shown, in one mouse strain (FVB/NJ), that offspring of dams on a high-fat diet have airway hyperreactivity, airway hyperinnervation and obesity as adults. Here we test whether these pathologies are present in immature offspring of dams on high-fat diet or develop with adulthood, using diverse outbred (DO) mice. We hypothesize that offspring born to dams given a high-fat diet will develop airway hyperinnervation and resulting airway hyperresponsiveness independent of genetic background. Methods: Six-week female DO mice were fed either a 45% fat (high-fat diet; HFD) or 14% fat diet (regular diet; RD) for 8 weeks before breeding, during pregnancy, and during lactation. After weaning, all offspring were fed a regular diet. Bronchoconstriction to inhaled 5-HT (1-100mM) was measured in anesthetized, paralyzed, and mechanically ventilated offspring before and after vagotomy at 8, 12, and 16 weeks of age. Traches of offspring were collected at 4, 8, 12, and 16 weeks, fixed with Zamboni’s and labeled with PGP9.5 antibody to identify nerves. Tracheas were optical cleared, airway nerves imaged using confocal microscopy, and 3D modeled using IMARIS software. DATA/RESULTS: At birth offspring born to dams on a HFD were normal weight. However, by 4 weeks of age, these offspring had a higher % body fat and significantly increased body weight. By 12 weeks of age offspring born to dams on a HFD also had significantly increased fasting insulin and glucose accompanied by insulin resistance. At 12 weeks, offspring of dams on a HFD had increased airway epithelial sensory nerve innervation that was significantly increased at 16 weeks. Importantly, 16 week old offspring born to dams on a HFD had also developed significantly increased airway bronchoconstriction to inhaled 5-HT compared to offspring of dams on a RD. Notably, increased bronchoconstriction in offspring of HFD dams was blocked by bilateral vagotomy, indicating it was mediated by airway nerves (5-HT is known to induce bronchoconstriction via a reflex). SUMMARY OF RESULTS: 16 week old offspring born to dams fed a HFD were obese, hyperinsulinemic, hyperglycemic, had increased airway sensory nerve innervation, and airway hyperresponsiveness to 5HT. Airway hyperresponsiveness was blocked by vagotomy indicating that airway nerves mediate this process. CONCLUSION: Independent of genetic background, maternal high-fat diet significantly impacts development of airway hyperinnervation in offspring leading to airway hyperresponsiveness, mediated by airway nerves, in adult offspring (16 weeks). Development of airway hyperresponsiveness is preceded by airway hyperinnervation, increased fasting insulin and glucose, and increase body weight and fat compared to offspring of dams on a regular diet. NIH, Ruth L Kirschstein T32 Training Grant- 1T32GM142619-01. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Bioactive Nanofiber-Hydrogel Composite Regulates Regenerative Microenvironment for Skeletal Muscle Regeneration after Volumetric Muscle Loss.

Volumetric muscle loss (VML) is a severe form of muscle trauma that exceeds the regenerative capacity of skeletal muscle tissue, leading to substantial functional impairment. The abnormal immune response and excessive reactive oxygen species (ROS) accumulation hinder muscle regeneration following VML. Here, an interfacial cross-linked hydrogel-poly(ε-caprolactone) nanofiber composite, that incorporates both biophysical and biochemical cues to modulate the immune and ROS microenvironment for enhanced VML repair, is engineered. The interfacial cross-linking is achieved through a Michael addition between catechol and thiol groups. The resultant composite exhibits enhanced mechanical strength without sacrificing porosity. Moreover, it mitigates oxidative stress and promotes macrophage polarization toward a pro-regenerative phenotype, both in vitro and in a mouse VML model. 4 weeks post-implantation, mice implanted with the composite show improved grip strength and walking performance, along with increased muscle fiber diameter, enhanced angiogenesis, and more nerve innervation compared to control mice. Collectively, these results suggest that the interfacial cross-linked nanofiber-hydrogel composite could serve as a cell-free and drug-free strategy for augmenting muscle regeneration by modulating the oxidative stress and immune microenvironment at the VML site.

Online Bayesian optimization of vagus nerve stimulation.

Objective.In bioelectronic medicine, neuromodulation therapies induce neural signals to the brain or organs, modifying their function. Stimulation devices capable of triggering exogenous neural signals using electrical waveforms require a complex and multi-dimensional parameter space to control such waveforms. Determining the best combination of parameters (waveform optimization or dosing) for treating a particular patient's illness is therefore challenging. Comprehensive parameter searching for an optimal stimulation effect is often infeasible in a clinical setting due to the size of the parameter space. Restricting this space, however, may lead to suboptimal therapeutic results, reduced responder rates, and adverse effects.Approach. As an alternative to a full parameter search, we present a flexible machine learning, data acquisition, and processing framework for optimizing neural stimulation parameters, requiring as few steps as possible using Bayesian optimization. This optimization builds a model of the neural and physiological responses to stimulations, enabling it to optimize stimulation parameters and provide estimates of the accuracy of the response model. The vagus nerve (VN) innervates, among other thoracic and visceral organs, the heart, thus controlling heart rate (HR), making it an ideal candidate for demonstrating the effectiveness of our approach.Main results.The efficacy of our optimization approach was first evaluated on simulated neural responses, then applied to VN stimulation intraoperatively in porcine subjects. Optimization converged quickly on parameters achieving target HRs and optimizing neural B-fiber activations despite high intersubject variability.Significance.An optimized stimulation waveform was achieved in real time with far fewer stimulations than required by alternative optimization strategies, thus minimizing exposure to side effects. Uncertainty estimates helped avoiding stimulations outside a safe range. Our approach shows that a complex set of neural stimulation parameters can be optimized in real-time for a patient to achieve a personalized precision dosing.

Overview of Ventilator-Associated Pneumonia in Traumatic Cervical Spinal Injury in Trauma Center of Nepal

Background Cervical spine, crucial for nerve innervation and head and neck motion, is vulnerable to injury due to its over-reliance on ligaments. This study examines the increasing incidence of traumatic spinal cord injuries, particularly in fall and traffic accidents, with respiratory complications being the leading cause of morbidity and mortality, with VAP being a significant complication. MethodsA retrospective cross-section study involving 52 patient data, using self-prepared proforma. The patient’s age, sex, injury severity, and CPIS score were used to determine VAP.ResultsThe study involved 52 patients with a mean age of 50.96. Of these, 67.3% were male and 11.5% female, with 45-60 years being the most common age group. The most severe spinal injury patients, i.e., ASIA A Neurology, developed VAP. Patients with prolonged ICU stay and intubation days also developed VAP, but no statistical significance was seen (P-value: 0.3941 and 0.4751). Mortality had a significant association with VAP (P-value: 0.023). Acinetobacter Baumann was the most common microorganism causing VAP, while Staphylococcus aureus was the least common. The most sensitive antibiotics for isolated organisms were Polymyxin B, Amikacin, Colistin, and Levofloxacin.Conclusions The study found a high prevalence of ventilator association pneumonia (VAP) in cervical spine fracture patients, with mortality associated with the most common organism being Acinetobacter, sensitivity to Polymyxin b. Further monitoring and implementation of VAP prevention strategies are recommended.

Modified technique improves efficacy for in-office posterior nasal nerve ablation.

Posterior nasal nerve (PNN) ablation is a minimally invasive treatment option for patients with chronic rhinitis. Recent evidence shows that parasympathetic innervation of the nasal cavity is more extensive and there are many fibers posterior to the lateral attachment of the middle turbinate. We describe a modified ablative technique that targets the extensive innervation of the posterior nasal nerves. Description of the technique and retrospective cohort analysis. In addition to the traditional radiofrequency and cryoablation targets, three additional treatment sites posterior to the middle turbinate were targeted using radiofrequency ablation, as well as one focused treatment posteroinferior to the middle turbinate attachment using cryotherapy ablation. The primary outcome collected was a 30% improvement in overall rhinitis symptoms. Forty-five patients received treatment and completed 3-month follow-up using the modified technique for radiofrequency and cryotherapy PNN ablation. Previously, our institution documented a 64.5% responder rate at 3 months. After introducing the modified technique, the response rate at 3 months significantly improved (64.5% vs. 91.1%, p = .004). This report suggests improved efficacy with implementation of the modified technique for in-office PNN ablation. Given the extensive nature of the post-ganglionic parasympathetic fibers of the nasal cavity which often emerge posterior to the middle turbinate attachment, a modified technique to target these branches should be considered. Prospective randomized studies comparing this modified technique to the traditional technique are needed. III.

Recording from Drosophila Larval Body Wall Muscles: Passive Membrane Properties and Basic Features of Synaptic Transmission.

The Drosophila larval body wall muscle preparation was first used for electrophysiological analysis in the 1970s. This preparation has become the "gold standard" for studying neuronal excitability as well as synaptic transmission. Here, we first describe the steps for performing intracellular recording from fly larval body wall muscles and then explain how to record and analyze spontaneous and evoked synaptic potentials. Methods used include larval dissection (filleting), identification of muscle fibers and their innervating nerves, the use of the micromanipulator and microelectrode in penetrating the muscle membrane, and nerve stimulation to evoke synaptic potentials.

Periampullary cancer and neurological interactions: current understanding and future research directions.

Periampullary cancer is a malignant tumor occurring around the ampullary region of the liver and pancreas, encompassing a variety of tissue types and sharing numerous biological characteristics, including interactions with the nervous system. The nervous system plays a crucial role in regulating organ development, maintaining physiological equilibrium, and ensuring life process plasticity, a role that is equally pivotal in oncology. Investigations into nerve-tumor interactions have unveiled their key part in controlling cancer progression, inhibiting anti-tumor immune responses, facilitating invasion and metastasis, and triggering neuropathic pain. Despite many mechanisms by which nerve fibers contribute to cancer advancement still being incompletely understood, the growing emphasis on the significance of nerves within the tumor microenvironment in recent years has set the stage for the development of groundbreaking therapies. This includes combining current neuroactive medications with established therapeutic protocols. This review centers on the mechanisms of Periampullary cancer's interactions with nerves, the influence of various types of nerve innervation on cancer evolution, and outlines the horizons for ongoing and forthcoming research.

Effects of Electric Field‐Modulated Conductive Hydrogel on Osseoperception and Osseointegration of Dental Implants

AbstractAchieving optimal implant restoration hinges on both robust osseointegration as the structural foundation and favorable osseoperception for advanced masticatory function. The significance of nerve innervation in the peri‐implant environment as the cornerstone of osseointegration and osseoperception is often underestimated. Despite the integral role of endogenous electric fields (EFs) in the human body, particularly in electrosensitive tissues like nerve tissue, the current approach involving external electrical stimulation is invasive and not clinically applicable. The present study introduces a conductive hydrogel designed to respond to endogenous EFs, aiming to foster nerve regeneration around dental implants to coordinate both osseointegration and osseoperception. The hydrogel promotes neurite outgrowth by upregulating intracellular Ca2+ concentration and activating subsequent pathways. Furthermore, the enhanced release of neuropeptides from neurocells improves the osteogenesis of osteoblasts. The impact of the conductive hydrogel on osseointegration and osseoperception is also thoroughly investigated in vivo. This conductive hydrogel represents a unique strategy for enhancing osseointegration and osseoperception within the endogenous EFs of the peri‐implant environment. This advancement opens the door to achieving the physiological and psychological integration of dental implants.

Alteration of Neurotrophic Factors and Innervation in Extraocular Muscles of Individuals With Concomitant Esotropia.

To determine whether neurotrophic factors and innervation in extraocular muscles (EOMs) were altered in different types of concomitant esotropia, and to explore the possible association between neurotrophic factors and innervation of EOMs in humans. Patients with concomitant esotropia who required strabismus surgery were recruited from January to December 2022. Lateral rectus EOMs were obtained from patients, and controls were obtained from deceased organ donors. Immunofluorescence (IF) was performed to detect innervation of EOMs (neurofilament and synaptophysin), and immunohistochemistry (IHC) was used to detect the neurotrophic factors insulin-like growth factor-1 (IGF-1), brain-derived neurotrophic factor (BDNF), glial cell-derived neurotrophic factor (GDNF), and neurotrophin-3 (NT-3). The positive IHC results were further verified using western blotting (WB). One-way ANOVA followed by a Dunnett's multiple comparison post hoc test was used for continuous variables and the χ2 test for categorical variables. Spearman correlation analysis was used for the correlation analysis. We collected lateral rectus EOM samples from acute and chronic types of concomitant esotropia and controls. Consistent with IHC, WB showed that IGF-1 was significantly increased in patients with acute acquired comitant esotropia or essential infantile esotropia compared with controls. In IF, synaptophysins were significantly increased only in acute acquired comitant esotropia compared with controls. Furthermore, Spearman correlation analysis showed that the correlation between IGF-1 and synaptophysin was borderline (P = 0.057) for patients with acute acquired comitant esotropia. Our study highlights the role of IGF-1 and altered innervation of EOMs in acute acquired comitant esotropia, suggesting that an effect of increased IGF-1 on nerve innervation may temporarily cause a compensatory increase in the strength of lateral rectus muscles.

A case of pituitary apoplexy presented with isolated complete oculomotor nerve palsy

The oculomotor nerve (CN3) innervates four extra-ocular muscles and contains parasympathetic fibers controlling pupillary light reflex (PLR). CN3 palsy with impaired PLR or complete CN3 palsy usually suggests a compressive lesion against the CN3 because the parasympathetic fibers located superficially on the cranial nerve trunk are affected. A cerebral aneurysm originated from posterior communicating artery, posterior cerebral artery or superior cerebellar artery is a common cause of isolated complete CN 3 palsy. Here, we reported a less common intracranial lesion causing isolated complete CN3 palsy for which the preceding recurrent temporal headaches before the CN3 palsy assisted the neurological localization.

Netrin-1 Role in Nociceptive Neuron Sprouting through Activation of DCC Signaling in a Rat Model of Bone Cancer Pain.

Bone cancer pain (BCP) is a common primary or metastatic bone cancer complication. Netrin-1 plays an essential role in neurite elongation and pain sensitization. This study aimed to determine the role of netrin-1 from the metastatic bone microenvironment in BCP development and identify the associated signaling pathway for the strategy of BCP management. The rat BCP model was established by intratibial implantation of Walker 256 cells. Von Frey filaments measured the mechanical pain threshold. Movement-induced pain was assessed using limb use scores. Expressions of associated molecules in the affected tibias or dorsal root ganglia (DRG) were measured by immunofluorescence, immunohistochemistry, real-time quantitative polymerase chain reaction, or western blotting. Transduction of deleted in colorectal cancer (DCC) signaling was inhibited by intrathecal injection of DCC-siRNA. In BCP rats, the presence of calcitonin gene-related peptide (CGRP)-positive nerve fibers increased in the metastatic bone lesions. The metastatic site showed enrichment of well-differentiated osteoclasts and expressions of netrin-1 and its attractive receptor DCC. Upregulation of DCC and increased phosphorylation levels of focal adhesion kinase (FAK) and Rac family small GTPase 1/Cell division cycle 42 (Rac1/Cdc42) were found in the DRG. Intrathecal administration of DCC-siRNA led to a significant reduction in FAK and Rac1/Cdc42 phosphorylation levels in the DRG, decreased nociceptive nerve innervation, and improved pain behaviors. Netrin-1 may contribute to the activation of the BCP by inducing nociceptive nerve innervation and improving pain behaviors.

Elongation of intercostal nerve cutaneous branches for breast and nipple neurotization during breast reconstruction after mastectomy for breast cancer: case-control study.

To restore sensation after breast reconstruction, a modified surgical approach was employed by identifying the cut fourth intercostal lateral cutaneous branch, elongating it with intercostal nerve grafts, and coapting it to the innervating nerve of the flap or by using direct neurotization of the spared nipple/skin. This was a retrospective case-control study including 56 patients who underwent breast neurotization surgery. Breast operations included immediate reconstruction after nipple-sparing mastectomy (36 patients), skin-sparing mastectomy (8 patients), and delayed reconstruction with nipple preservation (7 patients) or without nipple preservation (5 patients). Patients who underwent breast reconstruction without neurotization were included as the non-neurotization negative control group. The contralateral normal breasts were included as positive controls. The mean(s.d.) monofilament test values were 0.07(0.10) g for the positive control breasts and 179.13(143.31) g for the breasts operated on in the non-neurotization group. Breasts that underwent neurotization had significantly better sensation after surgery, with a mean(s.d.) value of 35.61(92.63) g (P < 0.001). The mean(s.d.) sensory return after neurotization was gradual; 138.17(143.65) g in the first 6 months, 59.55(116.46) g at 7-12 months, 14.54(62.27) g at 13-18 months, and 0.37(0.50) g at 19-24 months after surgery. Two patients had accidental rupture of the pleura, which was repaired uneventfully. One patient underwent re-exploration due to a lack of improvement 1.5 years after neurotization. Using the lateral cutaneous branch of the intercostal nerve as the innervating stump and elongating it with intercostal nerve grafts is a suitable technique to restore sensation after mastectomy. This method effectively innervates reconstructed breasts and spares the nipple/skin with minimal morbidity.

Automatic muscle impedance and nerve analyzer (AMINA) as a novel approach for classifying bioimpedance signals in intraoperative pelvic neuromonitoring

Frequent complications arising from low anterior resections include urinary and fecal incontinence, as well as sexual disorders, which are commonly associated with damage to the pelvic autonomic nerves during surgery. To assist the surgeon in preserving pelvic autonomic nerves, a novel approach for intraoperative pelvic neuromonitoring was investigated that is based on impedance measurements of the innervated organs. The objective of this work was to develop an algorithm called AMINA to classify the bioimpedance signals, with the goal of facilitating signal interpretation for the surgeon. Thirty patients included in a clinical investigation underwent nerve-preserving robotic rectal surgery using intraoperative pelvic neuromonitoring. Contraction of the urinary bladder and/or rectum, triggered by direct stimulation of the innervating nerves, resulted in a change in tissue impedance signal, allowing the nerves to be identified and preserved. Impedance signal characteristics in the time domain and the time–frequency domain were calculated and classified to develop the AMINA. Stimulation-induced positive impedance changes were statistically significantly different from negative stimulation responses by the percent amplitude of impedance change Amax in the time domain. Positive impedance changes and artifacts were distinguished by classifying wavelet scales resulting from peak detection in the continuous wavelet transform scalogram, which allowed implementation of a decision tree underlying the AMINA. The sensitivity of the software-based signal evaluation by the AMINA was 96.3%, whereas its specificity was 91.2%. This approach streamlines and automates the interpretation of impedance signals during intraoperative pelvic neuromonitoring.

The third head of the biceps brachii muscle exhibiting variable shape presentation: Prevalence, variability and clinical considerations

IntroductionThe third head of the biceps brachii is the predominant variation of the arm muscles. Awareness of muscular variations is essential for the management of upper limb pathologies. Variations in the shape of the muscles are rarely explored. This study aimed to describe the prevalence and anatomical presentation of the third head of the biceps brachii muscle (origin, insertion and innervation) with an emphasis on the shape and form variations. Materials and methodsBiceps brachii of eighty-nine cadavers were examined. The presence of the third head, its origin, shape patterns, blood supply, and nerve innervation were determined and recorded. ResultsThe third head of the biceps brachii was present in 20.2 %, with a prevalence of 22.2 % in males and 18.2 % in females. Half (50 %) of these were bilateral presentations. Most (92 %) of the third head of the biceps brachii variations were flat, thin and straight in shape. All the shape variation patterns were observed in males and on the left arm. The third head originated from the humerus on its anteromedial aspect in 92 % of cases. The musculocutaneous nerve innervated the third head of the biceps brachii in 96 % of the cases, and a nerve anomaly of musculocutaneous and median nerves innervated it in a single (4 %) case. The muscular branches of the brachial artery supplied the third head of the biceps brachii in all cases. ConclusionStudies on the variation of arm muscles may assist in identifying new patterns of morphological variations like the shape of the muscle and may aid in the accurate diagnosis and management of arm pathologies.