Nervous Structures Research Articles

Updates on Intraoperative Neurophysiology During Surgery for Spinal Dysraphism.

Spinal dysraphism is a group of disorders resulting from an embryologic failure of spinal cord development which can lead to a radicular-medullary mechanical stretch that generates vascular compromise and hypoxic-ischemic damage to the nervous structures of the conus-cauda region.Thus, the clinical relevance of the different types of spinal dysraphism is related to the possible neurologic deficits resulting from spinal cord tethering. The clinical presentation is heterogenous: from asymptomatic to very compromised patients. The indications and the time of a detethering surgery are still subject of debate, although there is an agreement on the high standards of treatment that have to be offered by the surgery. Intraoperative neurophysiology (ION) contributes to the safety of tethered cord surgery in reducing the risks of iatrogenic neurological damages.

Сравнение удовлетворенности голосом пациентов, оперированных на щитовидной железе при доброкачественных заболеваниях с применением различных методов визуализации нервных структур

Сравнение удовлетворенности голосом пациентов, оперированных на щитовидной железе при доброкачественных заболеваниях с применением различных методов визуализации нервных структур

Physical therapy — the main focus of modern ophthalmic rehabilitation

Ophthalmic rehabilitation consists of improving or maintaining the functions of the visual analyzer within the possibilities of the "therapeutic window". Ophthalmic rehabilitation involves physiotherapeutic methods, as well as additional ones that improve the condition of the body and indirectly affect the organ of vision. This article presents schematic algorithms of physiotherapeutic ophthalmic stimulation in neurodystrophic diseases of the visual organ and the main results of their multifactorial objective and subjective analysis. It was shown that even with the consistent visual resolution, treatment courses can help get positive changes at the level of nerve structures lasting for three to six months. This allows us to recommend physiotherapeutic ophthalmic stimulation for maintaining the therapeutic effects obtained after the main medical or surgical treatment.

Vascular decompression in the treatment of trigeminal neuralgia in dolichoectated vertebrobasilar artery

Dolichoectasia of vertebrobasilar artery is an uncommon and rare cause of trigeminal neuralgia. The article presents a case of successful treatment of a patient with trigeminal neuralgia caused by vertebrobasilar dolichoectasia. The technical complexity of the operation is due to the rigidity and tortuosity of a large-caliber vessel with perforating branches leading to the brain stem and limited space in the cerebellopontine angle. The implantation of Teflon wool in areas of neurovascular conflict is an effective surgical aid for complete elimination of trigeminal neuralgia while maintaining the anatomical integrity of the nerve structures and minimizing the risk to the patient.

The role of autonomic nervous system imbalance in the pathogenesis of hyperplastic laryngitis

A decrease in the mediator activity of nerve structures in organ tissues leads to the development of neurodystrophic changes and an increase in their sensitivity to certain influences. In these planets, it is important to assess the morphological characteristics of target structures, taking into account the neurodystrophic component of the disease. The aim of the study was to determine the activity of the peripheral adrenergic link of the trophic reflex and assessing the morphological features of the mucous membrane of the vocal folds in chronic hypertrophic laryngitis in patients with neurovegetative disorders. Materials and methods: the study involved 45 patients (37 men and 8 women) aged 23 to 72 years with a diagnosis of chronic hypertrophic laryngitis. An objective study of the upper respiratory tract, a cytological study of reprinted smears from the affected areas of the larynx, a study of the functional state of the ANS, as well as a histological and histochemical study of the removed tissue were carried out. Results. The examined patients were found to have dysfunction of the ANS in the form of insufficient or excessive autonomic support of activity. Morphological signs of keratinization of the epithelium of the mucous membrane of the vocal folds and its active proliferation, as well as dystrophic and atypical changes in cellular elements revealed as a sign of insufficient, tact and a sign of excessive vegetative support of activity. It was found that with insufficient vegetative support of activity, the proliferative activity of epithelial cells is more pronounced than that of a chemer with excess. The same applies to keratosis with atypia and dystrophic changes in the epithelium. Conclusions. The activity of the interstitial adrenergic nerve structures of the mucous membrane of the vocal folds correlates with the characteristics of autonomic activity. The weakening of the processes of synthesis, accumulation and excretion of neurotransmitter is associated with insufficient vegetative support of activity, and their strengthening is associated with excessive. The amount of neurotransmitter in peripheral nerve fibers and endings depends on the nature and intensity of manifestations of neurogenic dystrophies developing in executive tissues – targets of adrenergic innervation.

Targeted surface marker screening on neuronal structures in the human choroid

While choroidal neuronal control is known to be essential for retinal and ocular health, its mechanisms are not understood. Especially, the local choroidal innervation mediated by intrinsic choroidal neurons (ICN) remains enigmatic. Neuronal functionality depends on the synaptic neurotransmitters and neuroregulatory peptides involved as well as from membrane components presented on the cell surface. Since the neuronal surface molecular expression patterns in the choroid are currently unknown, we sought to determine the presence of various cluster-of-differentiation (CD) antigens in choroidal neuronal structures with a particular focus on ICN. Human choroids were prepared for immunohistochemistry and the pan-neuronal marker PGP9.5 was combined with CD15, CD24, CD29, CD34, CD46, CD49b, CD49e, CD56, CD58, CD59, CD71, CD81, CD90, CD146, CD147, CD151, CD165, CD171, CD184, CD200, CD271 and fluorescence- and confocal laser scanning-microscopy was used for documentation. The following antigens were found to be co-localized in PGP.9.5+ nerve fibers and ICN perikarya: CD29, CD34, CD56, CD81, CD90, CD146, CD147, CD151, CD171, CD200 and CD271, while all other CD markers where not detectable. Whereas CD24− and CD59− immunoreactivity was clearly absent in ICN perikarya, some neural processes of the choroidal stroma displayed CD24 and CD59 immunopositivity. While a multitude of the aforementioned CD-markers were indeed detected in nervous structures of the choroid, the CD24+ and CD59+ nerve fibers most likely have extrinsic origin from cranial ganglia since ICN cell bodies were found to lack both markers. These findings illustrate how the detailed analysis of CD molecules described here opens novel avenues for future functional studies on choroidal innervation and its control.

Retinoblastoma Radiotherapy Treatment Optimizations Through GATE Simulations

One of the most frequent children tumors in the area around the eyes is defined as retinoblastoma. Proton radiotherapy treatment is a particularly effective type of radiation therapy due to the prolonged survival rates of children with childhood cancers such as retinablastoma, continued growth of nearby organs and tissues, low radiation dose restriction of vision-related tissues and systems of these tissues. In this study, a geometry phantom including eyeball, lens, lacrimal gland, optic nerve, optic chiasm, retina, cancer, cornea and bone structures was modeled with Monte Carlo simulation tool GATE (vGATE 9.0). With this simulation, the doses absorbed by the tissues were calculated using the DoseActor and TLEDoseActor algorithms. Secondary doses were determined by the TLEDoseActor algorithm. Determination of secondary radiations is important because of the low radiation dose limit of tissues and systems that affect vision. The best treatment results were tried to be obtained by giving the beam thickness of the radiation used in our study, 4 different angles towards the target and different energies. These results show that it can be helpful in calculating a treatment plan for proton therapy in clinical practice.

An anatomical study of the tibial nerve branches innervating the posterior tibial artery.

The arteries of the lower limbs are innervated by vascular branches (VBs) originating from the lumbar sympathetic trunk and branches of the spinal nerve. Although lumbar sympathectomy is used to treat nonreconstructive critical lower limb ischemia (CLLI), it has limited long-term effects. In addition, the anatomical structure of tibial nerve (TN) VBs remain incompletely understood. This study aimed to clarify their anatomy and better inform the surgical approach for nonreconstructive CLLI. Thirty-six adult cadavers were dissected under surgical microscopy to observe the patterns and origin points of VBs under direct vision. The calves were anatomically divided into five equal segments, and the number of VB origin points found in each was expressed as a proportion of the total found in the whole calf. Immunofluorescence staining was used to identify the sympathetic nerve fibers of the VBs. Our results showed that the TN gave off 3-4 VBs to innervate the posterior tibial artery (PTA), and the distances between VBs origin points and the medial tibial condyle were: 24.7± 16.3 mm, 91.7± 66.1 mm, 199.6± 52.0 mm, 231.7± 38.5 mm, respectively. They were mainly located in the first (40.46%) and fourth (31.68%) calf segments, and immunofluorescence staining showed that they contained tyrosine hydroxylase-positive sympathetic nerve fibers. These findings indicate that the TN gives off VBs to innervate the PTA and that these contain sympathetic nerve fibers. Therefore, these VBs may need to be cut to surgically treat nonreconstructable CLLI.

A flexible protruding microelectrode array for neural interfacing in bioelectronic medicine

Recording neural signals from delicate autonomic nerves is a challenging task that requires the development of a low-invasive neural interface with highly selective, micrometer-sized electrodes. This paper reports on the development of a three-dimensional (3D) protruding thin-film microelectrode array (MEA), which is intended to be used for recording low-amplitude neural signals from pelvic nervous structures by penetrating the nerves transversely to reduce the distance to the axons. Cylindrical gold pillars (Ø 20 or 50 µm, ~60 µm height) were fabricated on a micromachined polyimide substrate in an electroplating process. Their sidewalls were insulated with parylene C, and their tips were optionally modified by wet etching and/or the application of a titanium nitride (TiN) coating. The microelectrodes modified by these combined techniques exhibited low impedances (~7 kΩ at 1 kHz for Ø 50 µm microelectrode with the exposed surface area of ~5000 µm²) and low intrinsic noise levels. Their functionalities were evaluated in an ex vivo pilot study with mouse retinae, in which spontaneous neuronal spikes were recorded with amplitudes of up to 66 µV. This novel process strategy for fabricating flexible, 3D neural interfaces with low-impedance microelectrodes has the potential to selectively record neural signals from not only delicate structures such as retinal cells but also autonomic nerves with improved signal quality to study neural circuits and develop stimulation strategies in bioelectronic medicine, e.g., for the control of vital digestive functions.

Radiation-induced salivary gland damage/dysfunction in head and neck cancer: Nano-bioengineering strategies and artificial intelligence for prevention, therapy and reparation

Saliva is produced by and secreted from salivary glands. It is an extra-cellular fluid, 98% water, plus electrolytes, mucus, white blood cells, epithelial cells, enzymes, and anti-microbial agents. Saliva serves a critical role in the maintenance of oral, dental, and general health and well-being. Hence, alteration(s) in the amount/quantity and/or quality of secreted saliva may induce the development of several oro-dental variations, thereby the negatively-impacting overall quality of life. Diverse factors may affect the process of saliva production and quantity/quality of secretion, including medications, systemic or local pathologies and/or reversible/irreversible damage. Herein, chemo- and/or radio-therapy, particularly, in cases of head and neck cancer, for example, are well-documented to induce serious damage and dysfunction to the radio-sensitive salivary gland tissue, resulting in hypo-salivation, xerostomia (dry mouth) as well as numerous other adverse Intra-/extra-oral, medical and quality-of-life issues. Indeed, radio-therapy inevitably causes damage to the normal head and neck tissues including nerve structures (brain stem, spinal cord, and brachial plexus), mucous membranes, and swallowing muscles. Current commercially-available remedies as well as therapeutic interventions provide only temporary symptom relief, hence, do not address irreversible glandular damage. Further, despite salivary gland-sparing techniques and modified dosing strategies, long-term hypo-function remains a significant problem. Although a single governing mechanism of radiation-induced salivary gland tissue damage and dysfunction has not been yet elucidated, the potential for synergy in radio-protection (mainly, and possibly -reparation) via a combinatorial approach of mechanistically distinct strategies, has been suggested and explored over the years. This is, undoubtfully, in parallel to the ongoing efforts in improving the precision, safety, delivery, and efficacy of clinical radiotherapy protocols/outcomes, and in designing, developing, evaluating and optimizing (for translation) new artificial intelligence, technological and bio-pharmaceutical alternatives, topics covered in this review.

Diagnosis and Treatment in frontobasal fractures

Traumatic brain injury can result in frontobasal fractures (FBF). The goals of treatment for FBF are to eliminate primary morbidity and/or prevent secondary morbidity. Of particular importance in this regard is the proximity of important sensory organs for hearing, vision, smell, and taste, as well as their supplying nervous structures. Medical history, clinical findings, or CT scan are necessary and should lead to an individual evaluation. Depending on the severity of the fractures, the following disciplines may be involved in the treatment of FBF: neurosurgery, plastic surgery, oral and maxillofacial surgery, and/or otorhinolaryngology. Particularly less invasive endoscopic endonasal therapy is aspecialty of otorhinolaryngologic surgeons and has not been widely established in other disciplines. The present work provides an overview of the current state of the art in terms of the following aspects, taking into account the current literature: anatomic principles, classification of fractures, diagnostics (in particular clinical examination, imaging, and laboratory chemistry tests), clinical symptoms, and treatment.

Acute thiamethoxam exposure induces hepatotoxicity and neurotoxicity in juvenile Chinese mitten crab (Eriocheir sinensis)

The similar nervous system structure between crustaceans and insects and the high-water solubility of thiamethoxam can lead to the more severe toxicity of thiamethoxam to crustaceans. However, the effects of thiamethoxam on crustaceans are unclear. Therefore, a 96-h acute toxicity test was performed to explore the hepatotoxicity and neurotoxicity effects of thiamethoxam on Chinese mitten crab (Eriocheir sinensis) at concentrations 0 µg/L, 150 µg/L and 300 µg/L. The antioxidant and detoxification systems (including phases I and II) were significantly activated after exposure of juvenile crabs to thiamethoxam for 24 h in 300 µg/L group, whereas the toxic activation effect in 150 μg/L group was delayed. Moreover, a similar pattern was observed for the transcription levels of immune-related genes. Further analysis of inflammatory signaling pathway-related genes showed that thiamethoxam exposure with 300 µg/L for 24 h may induce a pro-inflammatory response through the NF-κB pathway. In contrast, the gene expression levels in 150 µg/L group were significantly upregulated compared with 0 µg/L group after 96 h. In addition, although the acute exposure of 150 μg/L thiamethoxam did not seem to induce significant neurotoxicity, the acetylcholinesterase activity was significantly decreased in 300 μg/L group after thiamethoxam exposure for 96 h. Correspondingly, thiamethoxam exposure with 300 µg/L for 24 h resulted in significantly downregulated transcriptional levels of synaptic transmission-related genes (e.g. dopamine-, gamma-aminobutyric acid- and serotonin-related receptors). Therefore, thiamethoxam may be harmful and cause potential toxic threats such as neurotoxicity and metabolic damage to crustaceans.

Cadaveric and Ultrasound Validation of Percutaneous Electrolysis Approach at the Distal Biceps Tendon: A Potential Treatment for Biceps Tendinopathy.

Distal biceps brachii tendinopathy is a musculoskeletal pain condition-comprising chronic intrasubstance degeneration with alterations of the tendon structure-that is difficult to treat. Preliminary evidence suggests a positive effect for pain and related disability of percutaneous electrolysis treatment in patients with tendinopathy. Ultrasound is an excellent diagnostic tool to identify tendon injuries, such as tendinopathy, and to guide treatment approaches. Different approaches using ultrasound evaluation of the biceps tendon have been described. Our aim was to determine the validity and safety of a percutaneous electrolysis approach, targeting insertion of the distal tendon of biceps brachii, in both human (ultrasound-guided) and Thiel-embalmed cadaver (not ultrasound-guided) models. There were two approaches evaluated: an anterior approach with the elbow in extension and the forearm in supination and a posterior approach with the elbow in flexion and the forearm in pronation. A needle was inserted following the tendon up to its insertion into the radial tuberosity. The anterior approach, both in cadaveric study and US-guided intervention, revealed a close relationship between the distal biceps tendon and the brachial artery. The mean distance of the depth of the biceps tendon distal to the brachial artery was 0.21 ± 0.021 cm in the cadavers and 0.51 ± 0.024 cm in subjects. It was also found that the anterior approach has a potential technical difficulty due to the anatomical location of the brachial artery. With the posterior approach, it was possible to safely identify the tendon insertion and the needle approach, since no important vascular and nervous structures were visualized in the window of insertion of the needle. The clinician rated the posterior approach as low difficulty in all subjects. Current results would support a posterior approach with US guidance as a safe approach for applying the percutaneous electrolysis technique for insertional tendinopathies of the distal biceps brachii tendon. The current study did not assess the effectiveness of the proposed intervention; accordingly, future studies investigating the clinical effectiveness of the proposed intervention are needed.

Non-surgical approach to a paediatric pilocytic astrocytoma with MRI follow-up. Case report and brief literature review

Abstract Introduction: Pilocytic astrocytoma is a common tumour in paediatric patients. A low-grade glioma, it is most commonly treated by surgery, with various post-surgical side effects. New methods of treatment and follow-up are constantly evolving to offer alternative options to paediatric patients whose nerve structures are developing. Case presentation: A 9-year-old patient diagnosed with a pilocytic astrocytoma by MRI and histopathological examination underwent a biopsy and evacuation procedure of the cystic component after which the patient’s condition improved significantly. The ‘wait-and-see’ approach using MRI instead of total surgical excision of the tumour was preferred, and the patient had favourable results on control imaging. Conclusions: Paediatric patients suffering from pilocytic astrocytoma with favourable imaging and histopathological features may consider MRI follow-up instead of surgical excision until the character of the tumour changes or until the brain has reached full development.

Результат успешного лечения пациентки с сочетанной травмой, включающей оскольчатый переломовывих крестца, осложненный каудопатией

Introduction Combined injury, as a cause of death, occupies a central place in different age groups and is common for individuals ages 50 and younger. Most sacral fractures are traditionally repaired with screw or plate. However, the fixation can be unreliable in atypical anatomy of the upper sacral segment, U-shaped and H-shaped fractures, compression of nerve structures and failed fixation. Material and methods Reported is a case of a 29-year-old patient who suffered a severe concomitant injury including comminuted fracture-dislocation of the sacrum complicated by caudopathy. Results A good clinical and anatomical result was obtained. She developed a complete regression of neurological symptoms. The patient could ambulate without additional support. The function of the pelvic organs was restored. Discussion For a comparison, two methods were presented: lumbopelvic fixation using two rods and a transverse buckle and triangular fixation with a rod and an additional iliosacral screw. Lumbopelvic fixation is a surgical procedure for unstable pelvic ring injuries that allows immediate weight-bearing. Biomechanical tests showed greater primary stability with triangular lumbopelvic fixation than iliosacral fixation with no stress to the injured area. Bilateral lumbopelvic fixation with a transverse buckle allowed secure fixation of the lumbopelvic junction for fracture healing, protection of the sacroiliac joints preventing the development of transitional kyphosis and maintaining the spine balance with careful surgical handling of the soft tissues.

Topographic and Morphometric Study of the Foramen Spinosum of the Skull and Its Clinical Correlation.

Background and Objectives: The spinous foramen (FS) of the skull is an opening located in the greater wing of the sphenoid bone at the base of the skull, and it includes the middle meningeal vessels and the meningeal branch of the mandibular trigeminal nerve. The FS is commonly used as an anatomical landmark in neurosurgical procedures and neuroimaging of the middle cranial fossa because of its relationship with other cranial foramina and surrounding vascular and nervous structures. Thus, specific knowledge of its topography and possible anatomical variations is important regarding some surgical interventions and skull imaging. The aim of this study was to provide further details on the morphology of the FS of the skull by evaluating its topographic and morphometric relationships and correlating the findings with clinical practice. Materials and Methods: Thirty dried skulls of human skeletons from body donors from the collection of the Laboratory of Anatomical Microdissection at a medical school were used. The metric dimensions and variations of the FS and its relationship with adjacent bone structures were analyzed with an interface digital microscope. Results: The results showed the bilateral presence of the FS in all skulls; however, differences were observed in the shape, diameter, and topography in relation to the foramen ovale and the spine of the sphenoid. The FS was present in the greater wing of the sphenoid bone; however, in one skull, it was located in the lateral lamina of the pterygoid process. The FS was smaller than the foramen ovale. A round and oval FS shape was the most common (42.1% and 32.8% of the samples, respectively), followed by drop-shaped (12.5%) and irregular-shaped (12.5%) foramina. Conclusions: In conclusion, FS variations among individuals are common and must be considered by surgeons during skull base interventions in order to avoid accidents and postoperative complications.

A Quasi-Wireless Intraoperatory Neurophysiological Monitoring System

Intraoperative Neurophysiological Monitoring is a set of monitoring techniques that reads electrical activity generated by the nervous system structures during surgeries. In non-trivial surgeries, neurophysiologists require a significant number of electrical signals to be picked up to check the effects of the surgeon’s actions in real time or to confirm that the correct nerves are selected. As a result, cabling the patient in the operating room can become cumbersome. The proposed WIONM module solves part of the problem by converting a good part of those cables into a wireless connection that is substantially transparent to the human operator and the existing medical instrumentation.

It Is Time to Rethink Adult Glaucoma Screening Recommendations.

It Is Time to Rethink Adult Glaucoma Screening Recommendations.

Evaluation of B7-H3 Targeted Immunotherapy in a 3D Organoid Model of Craniopharyngioma.

A craniopharyngioma (CP) is a rare epithelial tumor of the sellar and parasellar region. CPs are difficult to treat due to their anatomical proximity to critical nervous structures, which limits the ability of the surgeon to completely resect the lesion, exposing patients to a high risk of recurrence. The treatment of craniopharyngiomas is primarily surgery and radiotherapy. So far, neither a cell line nor an animal model has been established, and thus data on other treatment options, such as chemotherapy and immunotherapy, are limited. Here, the expression profile of the pan-cancer antigen B7-H3 in various cancer types including CP was examined by immunohistochemistry. An in vitro organoid model was established by using fresh tissue biospecimens of CP. Based on the organoid model, we evaluated the antitumor efficacy of B7-H3-targeted immunotherapy on CP. As a result, the highest expression of B7-H3 was observed in CP tissues across various cancer types. Although B7-H3-targeted chimeric antigen-receptor T cells show obvious tumor-killing effects in the traditional 2D cell culture model, limited antitumor effects were observed in the 3D organoid model. The B7-H3-targeted antibody-DM1 conjugate exhibited a potent tumor suppression function both in 2D and 3D models. In conclusion, for the first time, we established an organoid model for CP and our results support that B7-H3 might serve as a promising target for antibody-drug conjugate therapy against craniopharyngioma.

Fast-acting and injectable cryoneurolysis device

Cryoneurolysis is an opioid-sparing therapy for long-lasting and reversible reduction of pain. We developed a nerve-selective method for cryoneurolysis by local injection of ice-slurry (− 5 to − 6 °C) that induced decrease in nocifensive response starting from about a week after treatment and lasting up to 8 weeks. In this study, we test the hypothesis that injection of colder slurry leads to faster onset of analgesia. Colder slurry (− 9ºC) was injected around the rat sciatic nerve to induce cryoneurolysis. Hematoxylin and Eosin (H&E) staining was used to examine histologic effects on surrounding tissues. Coherent anti-Stokes Raman scattering (CARS) microscopy was used to study effects on myelin sheaths. Functional tests were used to assess changes in sensory and motor function in the treated hind paw. No inflammation or scarring was detected in surrounding skin and muscle tissues at day 7 post slurry injection. Functional tests showed rapid onset reduction in mechanical pain sensitivity starting from day 1 and lasting up to day 98. CARS imaging demonstrated disintegration of myelin sheaths post treatment followed by complete recovery of nerve structure by day 140. In this study we showed that colder slurry (− 9 °C) produces more rapid onset and longer duration of analgesia, while remaining nerve-selective